// SPDX-License-Identifier: MIT
pragma solidity >=0.8.0;
import { IMessageLibManager } from "./IMessageLibManager.sol";
import { IMessagingComposer } from "./IMessagingComposer.sol";
import { IMessagingChannel } from "./IMessagingChannel.sol";
import { IMessagingContext } from "./IMessagingContext.sol";
struct MessagingParams {
    uint32 dstEid;
    bytes32 receiver;
    bytes message;
    bytes options;
    bool payInLzToken;
}
struct MessagingReceipt {
    bytes32 guid;
    uint64 nonce;
    MessagingFee fee;
}
struct MessagingFee {
    uint256 nativeFee;
    uint256 lzTokenFee;
}
struct Origin {
    uint32 srcEid;
    bytes32 sender;
    uint64 nonce;
}
interface ILayerZeroEndpointV2 is IMessageLibManager, IMessagingComposer, IMessagingChannel, IMessagingContext {
    event PacketSent(bytes encodedPayload, bytes options, address sendLibrary);
    event PacketVerified(Origin origin, address receiver, bytes32 payloadHash);
    event PacketDelivered(Origin origin, address receiver);
    event LzReceiveAlert(
        address indexed receiver,
        address indexed executor,
        Origin origin,
        bytes32 guid,
        uint256 gas,
        uint256 value,
        bytes message,
        bytes extraData,
        bytes reason
    );
    event LzTokenSet(address token);
    event DelegateSet(address sender, address delegate);
    function quote(MessagingParams calldata _params, address _sender) external view returns (MessagingFee memory);
    function send(
        MessagingParams calldata _params,
        address _refundAddress
    ) external payable returns (MessagingReceipt memory);
    function verify(Origin calldata _origin, address _receiver, bytes32 _payloadHash) external;
    function verifiable(Origin calldata _origin, address _receiver) external view returns (bool);
    function initializable(Origin calldata _origin, address _receiver) external view returns (bool);
    function lzReceive(
        Origin calldata _origin,
        address _receiver,
        bytes32 _guid,
        bytes calldata _message,
        bytes calldata _extraData
    ) external payable;
    // oapp can burn messages partially by calling this function with its own business logic if messages are verified in order
    function clear(address _oapp, Origin calldata _origin, bytes32 _guid, bytes calldata _message) external;
    function setLzToken(address _lzToken) external;
    function lzToken() external view returns (address);
    function nativeToken() external view returns (address);
    function setDelegate(address _delegate) external;
}
// SPDX-License-Identifier: MIT
pragma solidity >=0.8.0;
import { Origin } from "./ILayerZeroEndpointV2.sol";
interface ILayerZeroReceiver {
    function allowInitializePath(Origin calldata _origin) external view returns (bool);
    function nextNonce(uint32 _eid, bytes32 _sender) external view returns (uint64);
    function lzReceive(
        Origin calldata _origin,
        bytes32 _guid,
        bytes calldata _message,
        address _executor,
        bytes calldata _extraData
    ) external payable;
}
// SPDX-License-Identifier: MIT
pragma solidity >=0.8.0;
import { IERC165 } from "@openzeppelin/contracts/utils/introspection/IERC165.sol";
import { SetConfigParam } from "./IMessageLibManager.sol";
enum MessageLibType {
    Send,
    Receive,
    SendAndReceive
}
interface IMessageLib is IERC165 {
    function setConfig(address _oapp, SetConfigParam[] calldata _config) external;
    function getConfig(uint32 _eid, address _oapp, uint32 _configType) external view returns (bytes memory config);
    function isSupportedEid(uint32 _eid) external view returns (bool);
    // message libs of same major version are compatible
    function version() external view returns (uint64 major, uint8 minor, uint8 endpointVersion);
    function messageLibType() external view returns (MessageLibType);
}
// SPDX-License-Identifier: MIT
pragma solidity >=0.8.0;
struct SetConfigParam {
    uint32 eid;
    uint32 configType;
    bytes config;
}
interface IMessageLibManager {
    struct Timeout {
        address lib;
        uint256 expiry;
    }
    event LibraryRegistered(address newLib);
    event DefaultSendLibrarySet(uint32 eid, address newLib);
    event DefaultReceiveLibrarySet(uint32 eid, address newLib);
    event DefaultReceiveLibraryTimeoutSet(uint32 eid, address oldLib, uint256 expiry);
    event SendLibrarySet(address sender, uint32 eid, address newLib);
    event ReceiveLibrarySet(address receiver, uint32 eid, address newLib);
    event ReceiveLibraryTimeoutSet(address receiver, uint32 eid, address oldLib, uint256 timeout);
    function registerLibrary(address _lib) external;
    function isRegisteredLibrary(address _lib) external view returns (bool);
    function getRegisteredLibraries() external view returns (address[] memory);
    function setDefaultSendLibrary(uint32 _eid, address _newLib) external;
    function defaultSendLibrary(uint32 _eid) external view returns (address);
    function setDefaultReceiveLibrary(uint32 _eid, address _newLib, uint256 _gracePeriod) external;
    function defaultReceiveLibrary(uint32 _eid) external view returns (address);
    function setDefaultReceiveLibraryTimeout(uint32 _eid, address _lib, uint256 _expiry) external;
    function defaultReceiveLibraryTimeout(uint32 _eid) external view returns (address lib, uint256 expiry);
    function isSupportedEid(uint32 _eid) external view returns (bool);
    function isValidReceiveLibrary(address _receiver, uint32 _eid, address _lib) external view returns (bool);
    /// ------------------- OApp interfaces -------------------
    function setSendLibrary(address _oapp, uint32 _eid, address _newLib) external;
    function getSendLibrary(address _sender, uint32 _eid) external view returns (address lib);
    function isDefaultSendLibrary(address _sender, uint32 _eid) external view returns (bool);
    function setReceiveLibrary(address _oapp, uint32 _eid, address _newLib, uint256 _gracePeriod) external;
    function getReceiveLibrary(address _receiver, uint32 _eid) external view returns (address lib, bool isDefault);
    function setReceiveLibraryTimeout(address _oapp, uint32 _eid, address _lib, uint256 _expiry) external;
    function receiveLibraryTimeout(address _receiver, uint32 _eid) external view returns (address lib, uint256 expiry);
    function setConfig(address _oapp, address _lib, SetConfigParam[] calldata _params) external;
    function getConfig(
        address _oapp,
        address _lib,
        uint32 _eid,
        uint32 _configType
    ) external view returns (bytes memory config);
}
// SPDX-License-Identifier: MIT
pragma solidity >=0.8.0;
interface IMessagingChannel {
    event InboundNonceSkipped(uint32 srcEid, bytes32 sender, address receiver, uint64 nonce);
    event PacketNilified(uint32 srcEid, bytes32 sender, address receiver, uint64 nonce, bytes32 payloadHash);
    event PacketBurnt(uint32 srcEid, bytes32 sender, address receiver, uint64 nonce, bytes32 payloadHash);
    function eid() external view returns (uint32);
    // this is an emergency function if a message cannot be verified for some reasons
    // required to provide _nextNonce to avoid race condition
    function skip(address _oapp, uint32 _srcEid, bytes32 _sender, uint64 _nonce) external;
    function nilify(address _oapp, uint32 _srcEid, bytes32 _sender, uint64 _nonce, bytes32 _payloadHash) external;
    function burn(address _oapp, uint32 _srcEid, bytes32 _sender, uint64 _nonce, bytes32 _payloadHash) external;
    function nextGuid(address _sender, uint32 _dstEid, bytes32 _receiver) external view returns (bytes32);
    function inboundNonce(address _receiver, uint32 _srcEid, bytes32 _sender) external view returns (uint64);
    function outboundNonce(address _sender, uint32 _dstEid, bytes32 _receiver) external view returns (uint64);
    function inboundPayloadHash(
        address _receiver,
        uint32 _srcEid,
        bytes32 _sender,
        uint64 _nonce
    ) external view returns (bytes32);
    function lazyInboundNonce(address _receiver, uint32 _srcEid, bytes32 _sender) external view returns (uint64);
}
// SPDX-License-Identifier: MIT
pragma solidity >=0.8.0;
interface IMessagingComposer {
    event ComposeSent(address from, address to, bytes32 guid, uint16 index, bytes message);
    event ComposeDelivered(address from, address to, bytes32 guid, uint16 index);
    event LzComposeAlert(
        address indexed from,
        address indexed to,
        address indexed executor,
        bytes32 guid,
        uint16 index,
        uint256 gas,
        uint256 value,
        bytes message,
        bytes extraData,
        bytes reason
    );
    function composeQueue(
        address _from,
        address _to,
        bytes32 _guid,
        uint16 _index
    ) external view returns (bytes32 messageHash);
    function sendCompose(address _to, bytes32 _guid, uint16 _index, bytes calldata _message) external;
    function lzCompose(
        address _from,
        address _to,
        bytes32 _guid,
        uint16 _index,
        bytes calldata _message,
        bytes calldata _extraData
    ) external payable;
}
// SPDX-License-Identifier: MIT
pragma solidity >=0.8.0;
interface IMessagingContext {
    function isSendingMessage() external view returns (bool);
    function getSendContext() external view returns (uint32 dstEid, address sender);
}
// SPDX-License-Identifier: MIT
pragma solidity >=0.8.0;
import { MessagingFee } from "./ILayerZeroEndpointV2.sol";
import { IMessageLib } from "./IMessageLib.sol";
struct Packet {
    uint64 nonce;
    uint32 srcEid;
    address sender;
    uint32 dstEid;
    bytes32 receiver;
    bytes32 guid;
    bytes message;
}
interface ISendLib is IMessageLib {
    function send(
        Packet calldata _packet,
        bytes calldata _options,
        bool _payInLzToken
    ) external returns (MessagingFee memory, bytes memory encodedPacket);
    function quote(
        Packet calldata _packet,
        bytes calldata _options,
        bool _payInLzToken
    ) external view returns (MessagingFee memory);
    function setTreasury(address _treasury) external;
    function withdrawFee(address _to, uint256 _amount) external;
    function withdrawLzTokenFee(address _lzToken, address _to, uint256 _amount) external;
}
// SPDX-License-Identifier: LZBL-1.2
pragma solidity ^0.8.20;
library AddressCast {
    error AddressCast_InvalidSizeForAddress();
    error AddressCast_InvalidAddress();
    function toBytes32(bytes calldata _addressBytes) internal pure returns (bytes32 result) {
        if (_addressBytes.length > 32) revert AddressCast_InvalidAddress();
        result = bytes32(_addressBytes);
        unchecked {
            uint256 offset = 32 - _addressBytes.length;
            result = result >> (offset * 8);
        }
    }
    function toBytes32(address _address) internal pure returns (bytes32 result) {
        result = bytes32(uint256(uint160(_address)));
    }
    function toBytes(bytes32 _addressBytes32, uint256 _size) internal pure returns (bytes memory result) {
        if (_size == 0 || _size > 32) revert AddressCast_InvalidSizeForAddress();
        result = new bytes(_size);
        unchecked {
            uint256 offset = 256 - _size * 8;
            assembly {
                mstore(add(result, 32), shl(offset, _addressBytes32))
            }
        }
    }
    function toAddress(bytes32 _addressBytes32) internal pure returns (address result) {
        result = address(uint160(uint256(_addressBytes32)));
    }
    function toAddress(bytes calldata _addressBytes) internal pure returns (address result) {
        if (_addressBytes.length != 20) revert AddressCast_InvalidAddress();
        result = address(bytes20(_addressBytes));
    }
}
// SPDX-License-Identifier: LZBL-1.2
pragma solidity ^0.8.20;
import { Packet } from "../../interfaces/ISendLib.sol";
import { AddressCast } from "../../libs/AddressCast.sol";
library PacketV1Codec {
    using AddressCast for address;
    using AddressCast for bytes32;
    uint8 internal constant PACKET_VERSION = 1;
    // header (version + nonce + path)
    // version
    uint256 private constant PACKET_VERSION_OFFSET = 0;
    //    nonce
    uint256 private constant NONCE_OFFSET = 1;
    //    path
    uint256 private constant SRC_EID_OFFSET = 9;
    uint256 private constant SENDER_OFFSET = 13;
    uint256 private constant DST_EID_OFFSET = 45;
    uint256 private constant RECEIVER_OFFSET = 49;
    // payload (guid + message)
    uint256 private constant GUID_OFFSET = 81; // keccak256(nonce + path)
    uint256 private constant MESSAGE_OFFSET = 113;
    function encode(Packet memory _packet) internal pure returns (bytes memory encodedPacket) {
        encodedPacket = abi.encodePacked(
            PACKET_VERSION,
            _packet.nonce,
            _packet.srcEid,
            _packet.sender.toBytes32(),
            _packet.dstEid,
            _packet.receiver,
            _packet.guid,
            _packet.message
        );
    }
    function encodePacketHeader(Packet memory _packet) internal pure returns (bytes memory) {
        return
            abi.encodePacked(
                PACKET_VERSION,
                _packet.nonce,
                _packet.srcEid,
                _packet.sender.toBytes32(),
                _packet.dstEid,
                _packet.receiver
            );
    }
    function encodePayload(Packet memory _packet) internal pure returns (bytes memory) {
        return abi.encodePacked(_packet.guid, _packet.message);
    }
    function header(bytes calldata _packet) internal pure returns (bytes calldata) {
        return _packet[0:GUID_OFFSET];
    }
    function version(bytes calldata _packet) internal pure returns (uint8) {
        return uint8(bytes1(_packet[PACKET_VERSION_OFFSET:NONCE_OFFSET]));
    }
    function nonce(bytes calldata _packet) internal pure returns (uint64) {
        return uint64(bytes8(_packet[NONCE_OFFSET:SRC_EID_OFFSET]));
    }
    function srcEid(bytes calldata _packet) internal pure returns (uint32) {
        return uint32(bytes4(_packet[SRC_EID_OFFSET:SENDER_OFFSET]));
    }
    function sender(bytes calldata _packet) internal pure returns (bytes32) {
        return bytes32(_packet[SENDER_OFFSET:DST_EID_OFFSET]);
    }
    function senderAddressB20(bytes calldata _packet) internal pure returns (address) {
        return sender(_packet).toAddress();
    }
    function dstEid(bytes calldata _packet) internal pure returns (uint32) {
        return uint32(bytes4(_packet[DST_EID_OFFSET:RECEIVER_OFFSET]));
    }
    function receiver(bytes calldata _packet) internal pure returns (bytes32) {
        return bytes32(_packet[RECEIVER_OFFSET:GUID_OFFSET]);
    }
    function receiverB20(bytes calldata _packet) internal pure returns (address) {
        return receiver(_packet).toAddress();
    }
    function guid(bytes calldata _packet) internal pure returns (bytes32) {
        return bytes32(_packet[GUID_OFFSET:MESSAGE_OFFSET]);
    }
    function message(bytes calldata _packet) internal pure returns (bytes calldata) {
        return bytes(_packet[MESSAGE_OFFSET:]);
    }
    function payload(bytes calldata _packet) internal pure returns (bytes calldata) {
        return bytes(_packet[GUID_OFFSET:]);
    }
    function payloadHash(bytes calldata _packet) internal pure returns (bytes32) {
        return keccak256(payload(_packet));
    }
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.20;
// @dev Import the 'MessagingFee' and 'MessagingReceipt' so it's exposed to OApp implementers
// solhint-disable-next-line no-unused-import
import { OAppSender, MessagingFee, MessagingReceipt } from "./OAppSender.sol";
// @dev Import the 'Origin' so it's exposed to OApp implementers
// solhint-disable-next-line no-unused-import
import { OAppReceiver, Origin } from "./OAppReceiver.sol";
import { OAppCore } from "./OAppCore.sol";
/**
 * @title OApp
 * @dev Abstract contract serving as the base for OApp implementation, combining OAppSender and OAppReceiver functionality.
 */
abstract contract OApp is OAppSender, OAppReceiver {
    /**
     * @dev Constructor to initialize the OApp with the provided endpoint and owner.
     * @param _endpoint The address of the LOCAL LayerZero endpoint.
     * @param _delegate The delegate capable of making OApp configurations inside of the endpoint.
     */
    constructor(address _endpoint, address _delegate) OAppCore(_endpoint, _delegate) {}
    /**
     * @notice Retrieves the OApp version information.
     * @return senderVersion The version of the OAppSender.sol implementation.
     * @return receiverVersion The version of the OAppReceiver.sol implementation.
     */
    function oAppVersion()
        public
        pure
        virtual
        override(OAppSender, OAppReceiver)
        returns (uint64 senderVersion, uint64 receiverVersion)
    {
        return (SENDER_VERSION, RECEIVER_VERSION);
    }
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.20;
import { Ownable } from "@openzeppelin/contracts/access/Ownable.sol";
import { IOAppCore, ILayerZeroEndpointV2 } from "./interfaces/IOAppCore.sol";
/**
 * @title OAppCore
 * @dev Abstract contract implementing the IOAppCore interface with basic OApp configurations.
 */
abstract contract OAppCore is IOAppCore, Ownable {
    // The LayerZero endpoint associated with the given OApp
    ILayerZeroEndpointV2 public immutable endpoint;
    // Mapping to store peers associated with corresponding endpoints
    mapping(uint32 eid => bytes32 peer) public peers;
    /**
     * @dev Constructor to initialize the OAppCore with the provided endpoint and delegate.
     * @param _endpoint The address of the LOCAL Layer Zero endpoint.
     * @param _delegate The delegate capable of making OApp configurations inside of the endpoint.
     *
     * @dev The delegate typically should be set as the owner of the contract.
     */
    constructor(address _endpoint, address _delegate) {
        endpoint = ILayerZeroEndpointV2(_endpoint);
        if (_delegate == address(0)) revert InvalidDelegate();
        endpoint.setDelegate(_delegate);
    }
    /**
     * @notice Sets the peer address (OApp instance) for a corresponding endpoint.
     * @param _eid The endpoint ID.
     * @param _peer The address of the peer to be associated with the corresponding endpoint.
     *
     * @dev Only the owner/admin of the OApp can call this function.
     * @dev Indicates that the peer is trusted to send LayerZero messages to this OApp.
     * @dev Set this to bytes32(0) to remove the peer address.
     * @dev Peer is a bytes32 to accommodate non-evm chains.
     */
    function setPeer(uint32 _eid, bytes32 _peer) public virtual onlyOwner {
        _setPeer(_eid, _peer);
    }
    /**
     * @notice Sets the peer address (OApp instance) for a corresponding endpoint.
     * @param _eid The endpoint ID.
     * @param _peer The address of the peer to be associated with the corresponding endpoint.
     *
     * @dev Indicates that the peer is trusted to send LayerZero messages to this OApp.
     * @dev Set this to bytes32(0) to remove the peer address.
     * @dev Peer is a bytes32 to accommodate non-evm chains.
     */
    function _setPeer(uint32 _eid, bytes32 _peer) internal virtual {
        peers[_eid] = _peer;
        emit PeerSet(_eid, _peer);
    }
    /**
     * @notice Internal function to get the peer address associated with a specific endpoint; reverts if NOT set.
     * ie. the peer is set to bytes32(0).
     * @param _eid The endpoint ID.
     * @return peer The address of the peer associated with the specified endpoint.
     */
    function _getPeerOrRevert(uint32 _eid) internal view virtual returns (bytes32) {
        bytes32 peer = peers[_eid];
        if (peer == bytes32(0)) revert NoPeer(_eid);
        return peer;
    }
    /**
     * @notice Sets the delegate address for the OApp.
     * @param _delegate The address of the delegate to be set.
     *
     * @dev Only the owner/admin of the OApp can call this function.
     * @dev Provides the ability for a delegate to set configs, on behalf of the OApp, directly on the Endpoint contract.
     */
    function setDelegate(address _delegate) public onlyOwner {
        endpoint.setDelegate(_delegate);
    }
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.20;
import { IOAppReceiver, Origin } from "./interfaces/IOAppReceiver.sol";
import { OAppCore } from "./OAppCore.sol";
/**
 * @title OAppReceiver
 * @dev Abstract contract implementing the ILayerZeroReceiver interface and extending OAppCore for OApp receivers.
 */
abstract contract OAppReceiver is IOAppReceiver, OAppCore {
    // Custom error message for when the caller is not the registered endpoint/
    error OnlyEndpoint(address addr);
    // @dev The version of the OAppReceiver implementation.
    // @dev Version is bumped when changes are made to this contract.
    uint64 internal constant RECEIVER_VERSION = 2;
    /**
     * @notice Retrieves the OApp version information.
     * @return senderVersion The version of the OAppSender.sol contract.
     * @return receiverVersion The version of the OAppReceiver.sol contract.
     *
     * @dev Providing 0 as the default for OAppSender version. Indicates that the OAppSender is not implemented.
     * ie. this is a RECEIVE only OApp.
     * @dev If the OApp uses both OAppSender and OAppReceiver, then this needs to be override returning the correct versions.
     */
    function oAppVersion() public view virtual returns (uint64 senderVersion, uint64 receiverVersion) {
        return (0, RECEIVER_VERSION);
    }
    /**
     * @notice Indicates whether an address is an approved composeMsg sender to the Endpoint.
     * @dev _origin The origin information containing the source endpoint and sender address.
     *  - srcEid: The source chain endpoint ID.
     *  - sender: The sender address on the src chain.
     *  - nonce: The nonce of the message.
     * @dev _message The lzReceive payload.
     * @param _sender The sender address.
     * @return isSender Is a valid sender.
     *
     * @dev Applications can optionally choose to implement separate composeMsg senders that are NOT the bridging layer.
     * @dev The default sender IS the OAppReceiver implementer.
     */
    function isComposeMsgSender(
        Origin calldata /*_origin*/,
        bytes calldata /*_message*/,
        address _sender
    ) public view virtual returns (bool) {
        return _sender == address(this);
    }
    /**
     * @notice Checks if the path initialization is allowed based on the provided origin.
     * @param origin The origin information containing the source endpoint and sender address.
     * @return Whether the path has been initialized.
     *
     * @dev This indicates to the endpoint that the OApp has enabled msgs for this particular path to be received.
     * @dev This defaults to assuming if a peer has been set, its initialized.
     * Can be overridden by the OApp if there is other logic to determine this.
     */
    function allowInitializePath(Origin calldata origin) public view virtual returns (bool) {
        return peers[origin.srcEid] == origin.sender;
    }
    /**
     * @notice Retrieves the next nonce for a given source endpoint and sender address.
     * @dev _srcEid The source endpoint ID.
     * @dev _sender The sender address.
     * @return nonce The next nonce.
     *
     * @dev The path nonce starts from 1. If 0 is returned it means that there is NO nonce ordered enforcement.
     * @dev Is required by the off-chain executor to determine the OApp expects msg execution is ordered.
     * @dev This is also enforced by the OApp.
     * @dev By default this is NOT enabled. ie. nextNonce is hardcoded to return 0.
     */
    function nextNonce(uint32 /*_srcEid*/, bytes32 /*_sender*/) public view virtual returns (uint64 nonce) {
        return 0;
    }
    /**
     * @dev Entry point for receiving messages or packets from the endpoint.
     * @param _origin The origin information containing the source endpoint and sender address.
     *  - srcEid: The source chain endpoint ID.
     *  - sender: The sender address on the src chain.
     *  - nonce: The nonce of the message.
     * @param _guid The unique identifier for the received LayerZero message.
     * @param _message The payload of the received message.
     * @param _executor The address of the executor for the received message.
     * @param _extraData Additional arbitrary data provided by the corresponding executor.
     *
     * @dev Entry point for receiving msg/packet from the LayerZero endpoint.
     */
    function lzReceive(
        Origin calldata _origin,
        bytes32 _guid,
        bytes calldata _message,
        address _executor,
        bytes calldata _extraData
    ) public payable virtual {
        // Ensures that only the endpoint can attempt to lzReceive() messages to this OApp.
        if (address(endpoint) != msg.sender) revert OnlyEndpoint(msg.sender);
        // Ensure that the sender matches the expected peer for the source endpoint.
        if (_getPeerOrRevert(_origin.srcEid) != _origin.sender) revert OnlyPeer(_origin.srcEid, _origin.sender);
        // Call the internal OApp implementation of lzReceive.
        _lzReceive(_origin, _guid, _message, _executor, _extraData);
    }
    /**
     * @dev Internal function to implement lzReceive logic without needing to copy the basic parameter validation.
     */
    function _lzReceive(
        Origin calldata _origin,
        bytes32 _guid,
        bytes calldata _message,
        address _executor,
        bytes calldata _extraData
    ) internal virtual;
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.20;
import { SafeERC20, IERC20 } from "@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol";
import { MessagingParams, MessagingFee, MessagingReceipt } from "@layerzerolabs/lz-evm-protocol-v2/contracts/interfaces/ILayerZeroEndpointV2.sol";
import { OAppCore } from "./OAppCore.sol";
/**
 * @title OAppSender
 * @dev Abstract contract implementing the OAppSender functionality for sending messages to a LayerZero endpoint.
 */
abstract contract OAppSender is OAppCore {
    using SafeERC20 for IERC20;
    // Custom error messages
    error NotEnoughNative(uint256 msgValue);
    error LzTokenUnavailable();
    // @dev The version of the OAppSender implementation.
    // @dev Version is bumped when changes are made to this contract.
    uint64 internal constant SENDER_VERSION = 1;
    /**
     * @notice Retrieves the OApp version information.
     * @return senderVersion The version of the OAppSender.sol contract.
     * @return receiverVersion The version of the OAppReceiver.sol contract.
     *
     * @dev Providing 0 as the default for OAppReceiver version. Indicates that the OAppReceiver is not implemented.
     * ie. this is a SEND only OApp.
     * @dev If the OApp uses both OAppSender and OAppReceiver, then this needs to be override returning the correct versions
     */
    function oAppVersion() public view virtual returns (uint64 senderVersion, uint64 receiverVersion) {
        return (SENDER_VERSION, 0);
    }
    /**
     * @dev Internal function to interact with the LayerZero EndpointV2.quote() for fee calculation.
     * @param _dstEid The destination endpoint ID.
     * @param _message The message payload.
     * @param _options Additional options for the message.
     * @param _payInLzToken Flag indicating whether to pay the fee in LZ tokens.
     * @return fee The calculated MessagingFee for the message.
     *      - nativeFee: The native fee for the message.
     *      - lzTokenFee: The LZ token fee for the message.
     */
    function _quote(
        uint32 _dstEid,
        bytes memory _message,
        bytes memory _options,
        bool _payInLzToken
    ) internal view virtual returns (MessagingFee memory fee) {
        return
            endpoint.quote(
                MessagingParams(_dstEid, _getPeerOrRevert(_dstEid), _message, _options, _payInLzToken),
                address(this)
            );
    }
    /**
     * @dev Internal function to interact with the LayerZero EndpointV2.send() for sending a message.
     * @param _dstEid The destination endpoint ID.
     * @param _message The message payload.
     * @param _options Additional options for the message.
     * @param _fee The calculated LayerZero fee for the message.
     *      - nativeFee: The native fee.
     *      - lzTokenFee: The lzToken fee.
     * @param _refundAddress The address to receive any excess fee values sent to the endpoint.
     * @return receipt The receipt for the sent message.
     *      - guid: The unique identifier for the sent message.
     *      - nonce: The nonce of the sent message.
     *      - fee: The LayerZero fee incurred for the message.
     */
    function _lzSend(
        uint32 _dstEid,
        bytes memory _message,
        bytes memory _options,
        MessagingFee memory _fee,
        address _refundAddress
    ) internal virtual returns (MessagingReceipt memory receipt) {
        // @dev Push corresponding fees to the endpoint, any excess is sent back to the _refundAddress from the endpoint.
        uint256 messageValue = _payNative(_fee.nativeFee);
        if (_fee.lzTokenFee > 0) _payLzToken(_fee.lzTokenFee);
        return
            // solhint-disable-next-line check-send-result
            endpoint.send{ value: messageValue }(
                MessagingParams(_dstEid, _getPeerOrRevert(_dstEid), _message, _options, _fee.lzTokenFee > 0),
                _refundAddress
            );
    }
    /**
     * @dev Internal function to pay the native fee associated with the message.
     * @param _nativeFee The native fee to be paid.
     * @return nativeFee The amount of native currency paid.
     *
     * @dev If the OApp needs to initiate MULTIPLE LayerZero messages in a single transaction,
     * this will need to be overridden because msg.value would contain multiple lzFees.
     * @dev Should be overridden in the event the LayerZero endpoint requires a different native currency.
     * @dev Some EVMs use an ERC20 as a method for paying transactions/gasFees.
     * @dev The endpoint is EITHER/OR, ie. it will NOT support both types of native payment at a time.
     */
    function _payNative(uint256 _nativeFee) internal virtual returns (uint256 nativeFee) {
        if (msg.value != _nativeFee) revert NotEnoughNative(msg.value);
        return _nativeFee;
    }
    /**
     * @dev Internal function to pay the LZ token fee associated with the message.
     * @param _lzTokenFee The LZ token fee to be paid.
     *
     * @dev If the caller is trying to pay in the specified lzToken, then the lzTokenFee is passed to the endpoint.
     * @dev Any excess sent, is passed back to the specified _refundAddress in the _lzSend().
     */
    function _payLzToken(uint256 _lzTokenFee) internal virtual {
        // @dev Cannot cache the token because it is not immutable in the endpoint.
        address lzToken = endpoint.lzToken();
        if (lzToken == address(0)) revert LzTokenUnavailable();
        // Pay LZ token fee by sending tokens to the endpoint.
        IERC20(lzToken).safeTransferFrom(msg.sender, address(endpoint), _lzTokenFee);
    }
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.20;
import { ILayerZeroEndpointV2 } from "@layerzerolabs/lz-evm-protocol-v2/contracts/interfaces/ILayerZeroEndpointV2.sol";
/**
 * @title IOAppCore
 */
interface IOAppCore {
    // Custom error messages
    error OnlyPeer(uint32 eid, bytes32 sender);
    error NoPeer(uint32 eid);
    error InvalidEndpointCall();
    error InvalidDelegate();
    // Event emitted when a peer (OApp) is set for a corresponding endpoint
    event PeerSet(uint32 eid, bytes32 peer);
    /**
     * @notice Retrieves the OApp version information.
     * @return senderVersion The version of the OAppSender.sol contract.
     * @return receiverVersion The version of the OAppReceiver.sol contract.
     */
    function oAppVersion() external view returns (uint64 senderVersion, uint64 receiverVersion);
    /**
     * @notice Retrieves the LayerZero endpoint associated with the OApp.
     * @return iEndpoint The LayerZero endpoint as an interface.
     */
    function endpoint() external view returns (ILayerZeroEndpointV2 iEndpoint);
    /**
     * @notice Retrieves the peer (OApp) associated with a corresponding endpoint.
     * @param _eid The endpoint ID.
     * @return peer The peer address (OApp instance) associated with the corresponding endpoint.
     */
    function peers(uint32 _eid) external view returns (bytes32 peer);
    /**
     * @notice Sets the peer address (OApp instance) for a corresponding endpoint.
     * @param _eid The endpoint ID.
     * @param _peer The address of the peer to be associated with the corresponding endpoint.
     */
    function setPeer(uint32 _eid, bytes32 _peer) external;
    /**
     * @notice Sets the delegate address for the OApp Core.
     * @param _delegate The address of the delegate to be set.
     */
    function setDelegate(address _delegate) external;
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.20;
/**
 * @title IOAppMsgInspector
 * @dev Interface for the OApp Message Inspector, allowing examination of message and options contents.
 */
interface IOAppMsgInspector {
    // Custom error message for inspection failure
    error InspectionFailed(bytes message, bytes options);
    /**
     * @notice Allows the inspector to examine LayerZero message contents and optionally throw a revert if invalid.
     * @param _message The message payload to be inspected.
     * @param _options Additional options or parameters for inspection.
     * @return valid A boolean indicating whether the inspection passed (true) or failed (false).
     *
     * @dev Optionally done as a revert, OR use the boolean provided to handle the failure.
     */
    function inspect(bytes calldata _message, bytes calldata _options) external view returns (bool valid);
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.20;
/**
 * @dev Struct representing enforced option parameters.
 */
struct EnforcedOptionParam {
    uint32 eid; // Endpoint ID
    uint16 msgType; // Message Type
    bytes options; // Additional options
}
/**
 * @title IOAppOptionsType3
 * @dev Interface for the OApp with Type 3 Options, allowing the setting and combining of enforced options.
 */
interface IOAppOptionsType3 {
    // Custom error message for invalid options
    error InvalidOptions(bytes options);
    // Event emitted when enforced options are set
    event EnforcedOptionSet(EnforcedOptionParam[] _enforcedOptions);
    /**
     * @notice Sets enforced options for specific endpoint and message type combinations.
     * @param _enforcedOptions An array of EnforcedOptionParam structures specifying enforced options.
     */
    function setEnforcedOptions(EnforcedOptionParam[] calldata _enforcedOptions) external;
    /**
     * @notice Combines options for a given endpoint and message type.
     * @param _eid The endpoint ID.
     * @param _msgType The OApp message type.
     * @param _extraOptions Additional options passed by the caller.
     * @return options The combination of caller specified options AND enforced options.
     */
    function combineOptions(
        uint32 _eid,
        uint16 _msgType,
        bytes calldata _extraOptions
    ) external view returns (bytes memory options);
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.20;
import { ILayerZeroReceiver, Origin } from "@layerzerolabs/lz-evm-protocol-v2/contracts/interfaces/ILayerZeroReceiver.sol";
interface IOAppReceiver is ILayerZeroReceiver {
    /**
     * @notice Indicates whether an address is an approved composeMsg sender to the Endpoint.
     * @param _origin The origin information containing the source endpoint and sender address.
     *  - srcEid: The source chain endpoint ID.
     *  - sender: The sender address on the src chain.
     *  - nonce: The nonce of the message.
     * @param _message The lzReceive payload.
     * @param _sender The sender address.
     * @return isSender Is a valid sender.
     *
     * @dev Applications can optionally choose to implement a separate composeMsg sender that is NOT the bridging layer.
     * @dev The default sender IS the OAppReceiver implementer.
     */
    function isComposeMsgSender(
        Origin calldata _origin,
        bytes calldata _message,
        address _sender
    ) external view returns (bool isSender);
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.20;
import { Ownable } from "@openzeppelin/contracts/access/Ownable.sol";
import { IOAppOptionsType3, EnforcedOptionParam } from "../interfaces/IOAppOptionsType3.sol";
/**
 * @title OAppOptionsType3
 * @dev Abstract contract implementing the IOAppOptionsType3 interface with type 3 options.
 */
abstract contract OAppOptionsType3 is IOAppOptionsType3, Ownable {
    uint16 internal constant OPTION_TYPE_3 = 3;
    // @dev The "msgType" should be defined in the child contract.
    mapping(uint32 eid => mapping(uint16 msgType => bytes enforcedOption)) public enforcedOptions;
    /**
     * @dev Sets the enforced options for specific endpoint and message type combinations.
     * @param _enforcedOptions An array of EnforcedOptionParam structures specifying enforced options.
     *
     * @dev Only the owner/admin of the OApp can call this function.
     * @dev Provides a way for the OApp to enforce things like paying for PreCrime, AND/OR minimum dst lzReceive gas amounts etc.
     * @dev These enforced options can vary as the potential options/execution on the remote may differ as per the msgType.
     * eg. Amount of lzReceive() gas necessary to deliver a lzCompose() message adds overhead you dont want to pay
     * if you are only making a standard LayerZero message ie. lzReceive() WITHOUT sendCompose().
     */
    function setEnforcedOptions(EnforcedOptionParam[] calldata _enforcedOptions) public virtual onlyOwner {
        _setEnforcedOptions(_enforcedOptions);
    }
    /**
     * @dev Sets the enforced options for specific endpoint and message type combinations.
     * @param _enforcedOptions An array of EnforcedOptionParam structures specifying enforced options.
     *
     * @dev Provides a way for the OApp to enforce things like paying for PreCrime, AND/OR minimum dst lzReceive gas amounts etc.
     * @dev These enforced options can vary as the potential options/execution on the remote may differ as per the msgType.
     * eg. Amount of lzReceive() gas necessary to deliver a lzCompose() message adds overhead you dont want to pay
     * if you are only making a standard LayerZero message ie. lzReceive() WITHOUT sendCompose().
     */
    function _setEnforcedOptions(EnforcedOptionParam[] memory _enforcedOptions) internal virtual {
        for (uint256 i = 0; i < _enforcedOptions.length; i++) {
            // @dev Enforced options are only available for optionType 3, as type 1 and 2 dont support combining.
            _assertOptionsType3(_enforcedOptions[i].options);
            enforcedOptions[_enforcedOptions[i].eid][_enforcedOptions[i].msgType] = _enforcedOptions[i].options;
        }
        emit EnforcedOptionSet(_enforcedOptions);
    }
    /**
     * @notice Combines options for a given endpoint and message type.
     * @param _eid The endpoint ID.
     * @param _msgType The OAPP message type.
     * @param _extraOptions Additional options passed by the caller.
     * @return options The combination of caller specified options AND enforced options.
     *
     * @dev If there is an enforced lzReceive option:
     * - {gasLimit: 200k, msg.value: 1 ether} AND a caller supplies a lzReceive option: {gasLimit: 100k, msg.value: 0.5 ether}
     * - The resulting options will be {gasLimit: 300k, msg.value: 1.5 ether} when the message is executed on the remote lzReceive() function.
     * @dev This presence of duplicated options is handled off-chain in the verifier/executor.
     */
    function combineOptions(
        uint32 _eid,
        uint16 _msgType,
        bytes calldata _extraOptions
    ) public view virtual returns (bytes memory) {
        bytes memory enforced = enforcedOptions[_eid][_msgType];
        // No enforced options, pass whatever the caller supplied, even if it's empty or legacy type 1/2 options.
        if (enforced.length == 0) return _extraOptions;
        // No caller options, return enforced
        if (_extraOptions.length == 0) return enforced;
        // @dev If caller provided _extraOptions, must be type 3 as its the ONLY type that can be combined.
        if (_extraOptions.length >= 2) {
            _assertOptionsType3(_extraOptions);
            // @dev Remove the first 2 bytes containing the type from the _extraOptions and combine with enforced.
            return bytes.concat(enforced, _extraOptions[2:]);
        }
        // No valid set of options was found.
        revert InvalidOptions(_extraOptions);
    }
    /**
     * @dev Internal function to assert that options are of type 3.
     * @param _options The options to be checked.
     */
    function _assertOptionsType3(bytes memory _options) internal pure virtual {
        uint16 optionsType;
        assembly {
            optionsType := mload(add(_options, 2))
        }
        if (optionsType != OPTION_TYPE_3) revert InvalidOptions(_options);
    }
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.20;
import { Ownable } from "@openzeppelin/contracts/access/Ownable.sol";
import { IPreCrime } from "./interfaces/IPreCrime.sol";
import { IOAppPreCrimeSimulator, InboundPacket, Origin } from "./interfaces/IOAppPreCrimeSimulator.sol";
/**
 * @title OAppPreCrimeSimulator
 * @dev Abstract contract serving as the base for preCrime simulation functionality in an OApp.
 */
abstract contract OAppPreCrimeSimulator is IOAppPreCrimeSimulator, Ownable {
    // The address of the preCrime implementation.
    address public preCrime;
    /**
     * @dev Retrieves the address of the OApp contract.
     * @return The address of the OApp contract.
     *
     * @dev The simulator contract is the base contract for the OApp by default.
     * @dev If the simulator is a separate contract, override this function.
     */
    function oApp() external view virtual returns (address) {
        return address(this);
    }
    /**
     * @dev Sets the preCrime contract address.
     * @param _preCrime The address of the preCrime contract.
     */
    function setPreCrime(address _preCrime) public virtual onlyOwner {
        preCrime = _preCrime;
        emit PreCrimeSet(_preCrime);
    }
    /**
     * @dev Interface for pre-crime simulations. Always reverts at the end with the simulation results.
     * @param _packets An array of InboundPacket objects representing received packets to be delivered.
     *
     * @dev WARNING: MUST revert at the end with the simulation results.
     * @dev Gives the preCrime implementation the ability to mock sending packets to the lzReceive function,
     * WITHOUT actually executing them.
     */
    function lzReceiveAndRevert(InboundPacket[] calldata _packets) public payable virtual {
        for (uint256 i = 0; i < _packets.length; i++) {
            InboundPacket calldata packet = _packets[i];
            // Ignore packets that are not from trusted peers.
            if (!isPeer(packet.origin.srcEid, packet.origin.sender)) continue;
            // @dev Because a verifier is calling this function, it doesnt have access to executor params:
            //  - address _executor
            //  - bytes calldata _extraData
            // preCrime will NOT work for OApps that rely on these two parameters inside of their _lzReceive().
            // They are instead stubbed to default values, address(0) and bytes("")
            // @dev Calling this.lzReceiveSimulate removes ability for assembly return 0 callstack exit,
            // which would cause the revert to be ignored.
            this.lzReceiveSimulate{ value: packet.value }(
                packet.origin,
                packet.guid,
                packet.message,
                packet.executor,
                packet.extraData
            );
        }
        // @dev Revert with the simulation results. msg.sender must implement IPreCrime.buildSimulationResult().
        revert SimulationResult(IPreCrime(msg.sender).buildSimulationResult());
    }
    /**
     * @dev Is effectively an internal function because msg.sender must be address(this).
     * Allows resetting the call stack for 'internal' calls.
     * @param _origin The origin information containing the source endpoint and sender address.
     *  - srcEid: The source chain endpoint ID.
     *  - sender: The sender address on the src chain.
     *  - nonce: The nonce of the message.
     * @param _guid The unique identifier of the packet.
     * @param _message The message payload of the packet.
     * @param _executor The executor address for the packet.
     * @param _extraData Additional data for the packet.
     */
    function lzReceiveSimulate(
        Origin calldata _origin,
        bytes32 _guid,
        bytes calldata _message,
        address _executor,
        bytes calldata _extraData
    ) external payable virtual {
        // @dev Ensure ONLY can be called 'internally'.
        if (msg.sender != address(this)) revert OnlySelf();
        _lzReceiveSimulate(_origin, _guid, _message, _executor, _extraData);
    }
    /**
     * @dev Internal function to handle the OAppPreCrimeSimulator simulated receive.
     * @param _origin The origin information.
     *  - srcEid: The source chain endpoint ID.
     *  - sender: The sender address from the src chain.
     *  - nonce: The nonce of the LayerZero message.
     * @param _guid The GUID of the LayerZero message.
     * @param _message The LayerZero message.
     * @param _executor The address of the off-chain executor.
     * @param _extraData Arbitrary data passed by the msg executor.
     *
     * @dev Enables the preCrime simulator to mock sending lzReceive() messages,
     * routes the msg down from the OAppPreCrimeSimulator, and back up to the OAppReceiver.
     */
    function _lzReceiveSimulate(
        Origin calldata _origin,
        bytes32 _guid,
        bytes calldata _message,
        address _executor,
        bytes calldata _extraData
    ) internal virtual;
    /**
     * @dev checks if the specified peer is considered 'trusted' by the OApp.
     * @param _eid The endpoint Id to check.
     * @param _peer The peer to check.
     * @return Whether the peer passed is considered 'trusted' by the OApp.
     */
    function isPeer(uint32 _eid, bytes32 _peer) public view virtual returns (bool);
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.20;
// @dev Import the Origin so it's exposed to OAppPreCrimeSimulator implementers.
// solhint-disable-next-line no-unused-import
import { InboundPacket, Origin } from "../libs/Packet.sol";
/**
 * @title IOAppPreCrimeSimulator Interface
 * @dev Interface for the preCrime simulation functionality in an OApp.
 */
interface IOAppPreCrimeSimulator {
    // @dev simulation result used in PreCrime implementation
    error SimulationResult(bytes result);
    error OnlySelf();
    /**
     * @dev Emitted when the preCrime contract address is set.
     * @param preCrimeAddress The address of the preCrime contract.
     */
    event PreCrimeSet(address preCrimeAddress);
    /**
     * @dev Retrieves the address of the preCrime contract implementation.
     * @return The address of the preCrime contract.
     */
    function preCrime() external view returns (address);
    /**
     * @dev Retrieves the address of the OApp contract.
     * @return The address of the OApp contract.
     */
    function oApp() external view returns (address);
    /**
     * @dev Sets the preCrime contract address.
     * @param _preCrime The address of the preCrime contract.
     */
    function setPreCrime(address _preCrime) external;
    /**
     * @dev Mocks receiving a packet, then reverts with a series of data to infer the state/result.
     * @param _packets An array of LayerZero InboundPacket objects representing received packets.
     */
    function lzReceiveAndRevert(InboundPacket[] calldata _packets) external payable;
    /**
     * @dev checks if the specified peer is considered 'trusted' by the OApp.
     * @param _eid The endpoint Id to check.
     * @param _peer The peer to check.
     * @return Whether the peer passed is considered 'trusted' by the OApp.
     */
    function isPeer(uint32 _eid, bytes32 _peer) external view returns (bool);
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.20;
struct PreCrimePeer {
    uint32 eid;
    bytes32 preCrime;
    bytes32 oApp;
}
// TODO not done yet
interface IPreCrime {
    error OnlyOffChain();
    // for simulate()
    error PacketOversize(uint256 max, uint256 actual);
    error PacketUnsorted();
    error SimulationFailed(bytes reason);
    // for preCrime()
    error SimulationResultNotFound(uint32 eid);
    error InvalidSimulationResult(uint32 eid, bytes reason);
    error CrimeFound(bytes crime);
    function getConfig(bytes[] calldata _packets, uint256[] calldata _packetMsgValues) external returns (bytes memory);
    function simulate(
        bytes[] calldata _packets,
        uint256[] calldata _packetMsgValues
    ) external payable returns (bytes memory);
    function buildSimulationResult() external view returns (bytes memory);
    function preCrime(
        bytes[] calldata _packets,
        uint256[] calldata _packetMsgValues,
        bytes[] calldata _simulations
    ) external;
    function version() external view returns (uint64 major, uint8 minor);
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.20;
import { Origin } from "@layerzerolabs/lz-evm-protocol-v2/contracts/interfaces/ILayerZeroEndpointV2.sol";
import { PacketV1Codec } from "@layerzerolabs/lz-evm-protocol-v2/contracts/messagelib/libs/PacketV1Codec.sol";
/**
 * @title InboundPacket
 * @dev Structure representing an inbound packet received by the contract.
 */
struct InboundPacket {
    Origin origin; // Origin information of the packet.
    uint32 dstEid; // Destination endpointId of the packet.
    address receiver; // Receiver address for the packet.
    bytes32 guid; // Unique identifier of the packet.
    uint256 value; // msg.value of the packet.
    address executor; // Executor address for the packet.
    bytes message; // Message payload of the packet.
    bytes extraData; // Additional arbitrary data for the packet.
}
/**
 * @title PacketDecoder
 * @dev Library for decoding LayerZero packets.
 */
library PacketDecoder {
    using PacketV1Codec for bytes;
    /**
     * @dev Decode an inbound packet from the given packet data.
     * @param _packet The packet data to decode.
     * @return packet An InboundPacket struct representing the decoded packet.
     */
    function decode(bytes calldata _packet) internal pure returns (InboundPacket memory packet) {
        packet.origin = Origin(_packet.srcEid(), _packet.sender(), _packet.nonce());
        packet.dstEid = _packet.dstEid();
        packet.receiver = _packet.receiverB20();
        packet.guid = _packet.guid();
        packet.message = _packet.message();
    }
    /**
     * @dev Decode multiple inbound packets from the given packet data and associated message values.
     * @param _packets An array of packet data to decode.
     * @param _packetMsgValues An array of associated message values for each packet.
     * @return packets An array of InboundPacket structs representing the decoded packets.
     */
    function decode(
        bytes[] calldata _packets,
        uint256[] memory _packetMsgValues
    ) internal pure returns (InboundPacket[] memory packets) {
        packets = new InboundPacket[](_packets.length);
        for (uint256 i = 0; i < _packets.length; i++) {
            bytes calldata packet = _packets[i];
            packets[i] = PacketDecoder.decode(packet);
            // @dev Allows the verifier to specify the msg.value that gets passed in lzReceive.
            packets[i].value = _packetMsgValues[i];
        }
    }
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.20;
import { ERC20 } from "@openzeppelin/contracts/token/ERC20/ERC20.sol";
import { IOFT, OFTCore } from "./OFTCore.sol";
/**
 * @title OFT Contract
 * @dev OFT is an ERC-20 token that extends the functionality of the OFTCore contract.
 */
abstract contract OFT is OFTCore, ERC20 {
    /**
     * @dev Constructor for the OFT contract.
     * @param _name The name of the OFT.
     * @param _symbol The symbol of the OFT.
     * @param _lzEndpoint The LayerZero endpoint address.
     * @param _delegate The delegate capable of making OApp configurations inside of the endpoint.
     */
    constructor(
        string memory _name,
        string memory _symbol,
        address _lzEndpoint,
        address _delegate
    ) ERC20(_name, _symbol) OFTCore(decimals(), _lzEndpoint, _delegate) {}
    /**
     * @dev Retrieves the address of the underlying ERC20 implementation.
     * @return The address of the OFT token.
     *
     * @dev In the case of OFT, address(this) and erc20 are the same contract.
     */
    function token() public view returns (address) {
        return address(this);
    }
    /**
     * @notice Indicates whether the OFT contract requires approval of the 'token()' to send.
     * @return requiresApproval Needs approval of the underlying token implementation.
     *
     * @dev In the case of OFT where the contract IS the token, approval is NOT required.
     */
    function approvalRequired() external pure virtual returns (bool) {
        return false;
    }
    /**
     * @dev Burns tokens from the sender's specified balance.
     * @param _from The address to debit the tokens from.
     * @param _amountLD The amount of tokens to send in local decimals.
     * @param _minAmountLD The minimum amount to send in local decimals.
     * @param _dstEid The destination chain ID.
     * @return amountSentLD The amount sent in local decimals.
     * @return amountReceivedLD The amount received in local decimals on the remote.
     */
    function _debit(
        address _from,
        uint256 _amountLD,
        uint256 _minAmountLD,
        uint32 _dstEid
    ) internal virtual override returns (uint256 amountSentLD, uint256 amountReceivedLD) {
        (amountSentLD, amountReceivedLD) = _debitView(_amountLD, _minAmountLD, _dstEid);
        // @dev In NON-default OFT, amountSentLD could be 100, with a 10% fee, the amountReceivedLD amount is 90,
        // therefore amountSentLD CAN differ from amountReceivedLD.
        // @dev Default OFT burns on src.
        _burn(_from, amountSentLD);
    }
    /**
     * @dev Credits tokens to the specified address.
     * @param _to The address to credit the tokens to.
     * @param _amountLD The amount of tokens to credit in local decimals.
     * @dev _srcEid The source chain ID.
     * @return amountReceivedLD The amount of tokens ACTUALLY received in local decimals.
     */
    function _credit(
        address _to,
        uint256 _amountLD,
        uint32 /*_srcEid*/
    ) internal virtual override returns (uint256 amountReceivedLD) {
        if (_to == address(0x0)) _to = address(0xdead); // _mint(...) does not support address(0x0)
        // @dev Default OFT mints on dst.
        _mint(_to, _amountLD);
        // @dev In the case of NON-default OFT, the _amountLD MIGHT not be == amountReceivedLD.
        return _amountLD;
    }
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.20;
import { IERC20 } from "@openzeppelin/contracts/token/ERC20/IERC20.sol";
import { OApp, Origin } from "@layerzerolabs/oapp-evm/contracts/oapp/OApp.sol";
import { OAppOptionsType3 } from "@layerzerolabs/oapp-evm/contracts/oapp/libs/OAppOptionsType3.sol";
import { IOAppMsgInspector } from "@layerzerolabs/oapp-evm/contracts/oapp/interfaces/IOAppMsgInspector.sol";
import { OAppPreCrimeSimulator } from "@layerzerolabs/oapp-evm/contracts/precrime/OAppPreCrimeSimulator.sol";
import { IOFT, SendParam, OFTLimit, OFTReceipt, OFTFeeDetail, MessagingReceipt, MessagingFee } from "./interfaces/IOFT.sol";
import { OFTMsgCodec } from "./libs/OFTMsgCodec.sol";
import { OFTComposeMsgCodec } from "./libs/OFTComposeMsgCodec.sol";
/**
 * @title OFTCore
 * @dev Abstract contract for the OftChain (OFT) token.
 */
abstract contract OFTCore is IOFT, OApp, OAppPreCrimeSimulator, OAppOptionsType3 {
    using OFTMsgCodec for bytes;
    using OFTMsgCodec for bytes32;
    // @notice Provides a conversion rate when swapping between denominations of SD and LD
    //      - shareDecimals == SD == shared Decimals
    //      - localDecimals == LD == local decimals
    // @dev Considers that tokens have different decimal amounts on various chains.
    // @dev eg.
    //  For a token
    //      - locally with 4 decimals --> 1.2345 => uint(12345)
    //      - remotely with 2 decimals --> 1.23 => uint(123)
    //      - The conversion rate would be 10 ** (4 - 2) = 100
    //  @dev If you want to send 1.2345 -> (uint 12345), you CANNOT represent that value on the remote,
    //  you can only display 1.23 -> uint(123).
    //  @dev To preserve the dust that would otherwise be lost on that conversion,
    //  we need to unify a denomination that can be represented on ALL chains inside of the OFT mesh
    uint256 public immutable decimalConversionRate;
    // @notice Msg types that are used to identify the various OFT operations.
    // @dev This can be extended in child contracts for non-default oft operations
    // @dev These values are used in things like combineOptions() in OAppOptionsType3.sol.
    uint16 public constant SEND = 1;
    uint16 public constant SEND_AND_CALL = 2;
    // Address of an optional contract to inspect both 'message' and 'options'
    address public msgInspector;
    event MsgInspectorSet(address inspector);
    /**
     * @dev Constructor.
     * @param _localDecimals The decimals of the token on the local chain (this chain).
     * @param _endpoint The address of the LayerZero endpoint.
     * @param _delegate The delegate capable of making OApp configurations inside of the endpoint.
     */
    constructor(uint8 _localDecimals, address _endpoint, address _delegate) OApp(_endpoint, _delegate) {
        if (_localDecimals < sharedDecimals()) revert InvalidLocalDecimals();
        decimalConversionRate = 10 ** (_localDecimals - sharedDecimals());
    }
    /**
     * @notice Retrieves interfaceID and the version of the OFT.
     * @return interfaceId The interface ID.
     * @return version The version.
     *
     * @dev interfaceId: This specific interface ID is '0x02e49c2c'.
     * @dev version: Indicates a cross-chain compatible msg encoding with other OFTs.
     * @dev If a new feature is added to the OFT cross-chain msg encoding, the version will be incremented.
     * ie. localOFT version(x,1) CAN send messages to remoteOFT version(x,1)
     */
    function oftVersion() external pure virtual returns (bytes4 interfaceId, uint64 version) {
        return (type(IOFT).interfaceId, 1);
    }
    /**
     * @dev Retrieves the shared decimals of the OFT.
     * @return The shared decimals of the OFT.
     *
     * @dev Sets an implicit cap on the amount of tokens, over uint64.max() will need some sort of outbound cap / totalSupply cap
     * Lowest common decimal denominator between chains.
     * Defaults to 6 decimal places to provide up to 18,446,744,073,709.551615 units (max uint64).
     * For tokens exceeding this totalSupply(), they will need to override the sharedDecimals function with something smaller.
     * ie. 4 sharedDecimals would be 1,844,674,407,370,955.1615
     */
    function sharedDecimals() public view virtual returns (uint8) {
        return 6;
    }
    /**
     * @dev Sets the message inspector address for the OFT.
     * @param _msgInspector The address of the message inspector.
     *
     * @dev This is an optional contract that can be used to inspect both 'message' and 'options'.
     * @dev Set it to address(0) to disable it, or set it to a contract address to enable it.
     */
    function setMsgInspector(address _msgInspector) public virtual onlyOwner {
        msgInspector = _msgInspector;
        emit MsgInspectorSet(_msgInspector);
    }
    /**
     * @notice Provides the fee breakdown and settings data for an OFT. Unused in the default implementation.
     * @param _sendParam The parameters for the send operation.
     * @return oftLimit The OFT limit information.
     * @return oftFeeDetails The details of OFT fees.
     * @return oftReceipt The OFT receipt information.
     */
    function quoteOFT(
        SendParam calldata _sendParam
    )
        external
        view
        virtual
        returns (OFTLimit memory oftLimit, OFTFeeDetail[] memory oftFeeDetails, OFTReceipt memory oftReceipt)
    {
        uint256 minAmountLD = 0; // Unused in the default implementation.
        uint256 maxAmountLD = IERC20(this.token()).totalSupply(); // Unused in the default implementation.
        oftLimit = OFTLimit(minAmountLD, maxAmountLD);
        // Unused in the default implementation; reserved for future complex fee details.
        oftFeeDetails = new OFTFeeDetail[](0);
        // @dev This is the same as the send() operation, but without the actual send.
        // - amountSentLD is the amount in local decimals that would be sent from the sender.
        // - amountReceivedLD is the amount in local decimals that will be credited to the recipient on the remote OFT instance.
        // @dev The amountSentLD MIGHT not equal the amount the user actually receives. HOWEVER, the default does.
        (uint256 amountSentLD, uint256 amountReceivedLD) = _debitView(
            _sendParam.amountLD,
            _sendParam.minAmountLD,
            _sendParam.dstEid
        );
        oftReceipt = OFTReceipt(amountSentLD, amountReceivedLD);
    }
    /**
     * @notice Provides a quote for the send() operation.
     * @param _sendParam The parameters for the send() operation.
     * @param _payInLzToken Flag indicating whether the caller is paying in the LZ token.
     * @return msgFee The calculated LayerZero messaging fee from the send() operation.
     *
     * @dev MessagingFee: LayerZero msg fee
     *  - nativeFee: The native fee.
     *  - lzTokenFee: The lzToken fee.
     */
    function quoteSend(
        SendParam calldata _sendParam,
        bool _payInLzToken
    ) external view virtual returns (MessagingFee memory msgFee) {
        // @dev mock the amount to receive, this is the same operation used in the send().
        // The quote is as similar as possible to the actual send() operation.
        (, uint256 amountReceivedLD) = _debitView(_sendParam.amountLD, _sendParam.minAmountLD, _sendParam.dstEid);
        // @dev Builds the options and OFT message to quote in the endpoint.
        (bytes memory message, bytes memory options) = _buildMsgAndOptions(_sendParam, amountReceivedLD);
        // @dev Calculates the LayerZero fee for the send() operation.
        return _quote(_sendParam.dstEid, message, options, _payInLzToken);
    }
    /**
     * @dev Executes the send operation.
     * @param _sendParam The parameters for the send operation.
     * @param _fee The calculated fee for the send() operation.
     *      - nativeFee: The native fee.
     *      - lzTokenFee: The lzToken fee.
     * @param _refundAddress The address to receive any excess funds.
     * @return msgReceipt The receipt for the send operation.
     * @return oftReceipt The OFT receipt information.
     *
     * @dev MessagingReceipt: LayerZero msg receipt
     *  - guid: The unique identifier for the sent message.
     *  - nonce: The nonce of the sent message.
     *  - fee: The LayerZero fee incurred for the message.
     */
    function send(
        SendParam calldata _sendParam,
        MessagingFee calldata _fee,
        address _refundAddress
    ) external payable virtual returns (MessagingReceipt memory msgReceipt, OFTReceipt memory oftReceipt) {
        return _send(_sendParam, _fee, _refundAddress);
    }
    /**
     * @dev Internal function to execute the send operation.
     * @param _sendParam The parameters for the send operation.
     * @param _fee The calculated fee for the send() operation.
     *      - nativeFee: The native fee.
     *      - lzTokenFee: The lzToken fee.
     * @param _refundAddress The address to receive any excess funds.
     * @return msgReceipt The receipt for the send operation.
     * @return oftReceipt The OFT receipt information.
     *
     * @dev MessagingReceipt: LayerZero msg receipt
     *  - guid: The unique identifier for the sent message.
     *  - nonce: The nonce of the sent message.
     *  - fee: The LayerZero fee incurred for the message.
     */
    function _send(
        SendParam calldata _sendParam,
        MessagingFee calldata _fee,
        address _refundAddress
    ) internal virtual returns (MessagingReceipt memory msgReceipt, OFTReceipt memory oftReceipt) {
        // @dev Applies the token transfers regarding this send() operation.
        // - amountSentLD is the amount in local decimals that was ACTUALLY sent/debited from the sender.
        // - amountReceivedLD is the amount in local decimals that will be received/credited to the recipient on the remote OFT instance.
        (uint256 amountSentLD, uint256 amountReceivedLD) = _debit(
            msg.sender,
            _sendParam.amountLD,
            _sendParam.minAmountLD,
            _sendParam.dstEid
        );
        // @dev Builds the options and OFT message to quote in the endpoint.
        (bytes memory message, bytes memory options) = _buildMsgAndOptions(_sendParam, amountReceivedLD);
        // @dev Sends the message to the LayerZero endpoint and returns the LayerZero msg receipt.
        msgReceipt = _lzSend(_sendParam.dstEid, message, options, _fee, _refundAddress);
        // @dev Formulate the OFT receipt.
        oftReceipt = OFTReceipt(amountSentLD, amountReceivedLD);
        emit OFTSent(msgReceipt.guid, _sendParam.dstEid, msg.sender, amountSentLD, amountReceivedLD);
    }
    /**
     * @dev Internal function to build the message and options.
     * @param _sendParam The parameters for the send() operation.
     * @param _amountLD The amount in local decimals.
     * @return message The encoded message.
     * @return options The encoded options.
     */
    function _buildMsgAndOptions(
        SendParam calldata _sendParam,
        uint256 _amountLD
    ) internal view virtual returns (bytes memory message, bytes memory options) {
        bool hasCompose;
        // @dev This generated message has the msg.sender encoded into the payload so the remote knows who the caller is.
        (message, hasCompose) = OFTMsgCodec.encode(
            _sendParam.to,
            _toSD(_amountLD),
            // @dev Must be include a non empty bytes if you want to compose, EVEN if you dont need it on the remote.
            // EVEN if you dont require an arbitrary payload to be sent... eg. '0x01'
            _sendParam.composeMsg
        );
        // @dev Change the msg type depending if its composed or not.
        uint16 msgType = hasCompose ? SEND_AND_CALL : SEND;
        // @dev Combine the callers _extraOptions with the enforced options via the OAppOptionsType3.
        options = combineOptions(_sendParam.dstEid, msgType, _sendParam.extraOptions);
        // @dev Optionally inspect the message and options depending if the OApp owner has set a msg inspector.
        // @dev If it fails inspection, needs to revert in the implementation. ie. does not rely on return boolean
        address inspector = msgInspector; // caches the msgInspector to avoid potential double storage read
        if (inspector != address(0)) IOAppMsgInspector(inspector).inspect(message, options);
    }
    /**
     * @dev Internal function to handle the receive on the LayerZero endpoint.
     * @param _origin The origin information.
     *  - srcEid: The source chain endpoint ID.
     *  - sender: The sender address from the src chain.
     *  - nonce: The nonce of the LayerZero message.
     * @param _guid The unique identifier for the received LayerZero message.
     * @param _message The encoded message.
     * @dev _executor The address of the executor.
     * @dev _extraData Additional data.
     */
    function _lzReceive(
        Origin calldata _origin,
        bytes32 _guid,
        bytes calldata _message,
        address /*_executor*/, // @dev unused in the default implementation.
        bytes calldata /*_extraData*/ // @dev unused in the default implementation.
    ) internal virtual override {
        // @dev The src sending chain doesnt know the address length on this chain (potentially non-evm)
        // Thus everything is bytes32() encoded in flight.
        address toAddress = _message.sendTo().bytes32ToAddress();
        // @dev Credit the amountLD to the recipient and return the ACTUAL amount the recipient received in local decimals
        uint256 amountReceivedLD = _credit(toAddress, _toLD(_message.amountSD()), _origin.srcEid);
        if (_message.isComposed()) {
            // @dev Proprietary composeMsg format for the OFT.
            bytes memory composeMsg = OFTComposeMsgCodec.encode(
                _origin.nonce,
                _origin.srcEid,
                amountReceivedLD,
                _message.composeMsg()
            );
            // @dev Stores the lzCompose payload that will be executed in a separate tx.
            // Standardizes functionality for executing arbitrary contract invocation on some non-evm chains.
            // @dev The off-chain executor will listen and process the msg based on the src-chain-callers compose options passed.
            // @dev The index is used when a OApp needs to compose multiple msgs on lzReceive.
            // For default OFT implementation there is only 1 compose msg per lzReceive, thus its always 0.
            endpoint.sendCompose(toAddress, _guid, 0 /* the index of the composed message*/, composeMsg);
        }
        emit OFTReceived(_guid, _origin.srcEid, toAddress, amountReceivedLD);
    }
    /**
     * @dev Internal function to handle the OAppPreCrimeSimulator simulated receive.
     * @param _origin The origin information.
     *  - srcEid: The source chain endpoint ID.
     *  - sender: The sender address from the src chain.
     *  - nonce: The nonce of the LayerZero message.
     * @param _guid The unique identifier for the received LayerZero message.
     * @param _message The LayerZero message.
     * @param _executor The address of the off-chain executor.
     * @param _extraData Arbitrary data passed by the msg executor.
     *
     * @dev Enables the preCrime simulator to mock sending lzReceive() messages,
     * routes the msg down from the OAppPreCrimeSimulator, and back up to the OAppReceiver.
     */
    function _lzReceiveSimulate(
        Origin calldata _origin,
        bytes32 _guid,
        bytes calldata _message,
        address _executor,
        bytes calldata _extraData
    ) internal virtual override {
        _lzReceive(_origin, _guid, _message, _executor, _extraData);
    }
    /**
     * @dev Check if the peer is considered 'trusted' by the OApp.
     * @param _eid The endpoint ID to check.
     * @param _peer The peer to check.
     * @return Whether the peer passed is considered 'trusted' by the OApp.
     *
     * @dev Enables OAppPreCrimeSimulator to check whether a potential Inbound Packet is from a trusted source.
     */
    function isPeer(uint32 _eid, bytes32 _peer) public view virtual override returns (bool) {
        return peers[_eid] == _peer;
    }
    /**
     * @dev Internal function to remove dust from the given local decimal amount.
     * @param _amountLD The amount in local decimals.
     * @return amountLD The amount after removing dust.
     *
     * @dev Prevents the loss of dust when moving amounts between chains with different decimals.
     * @dev eg. uint(123) with a conversion rate of 100 becomes uint(100).
     */
    function _removeDust(uint256 _amountLD) internal view virtual returns (uint256 amountLD) {
        return (_amountLD / decimalConversionRate) * decimalConversionRate;
    }
    /**
     * @dev Internal function to convert an amount from shared decimals into local decimals.
     * @param _amountSD The amount in shared decimals.
     * @return amountLD The amount in local decimals.
     */
    function _toLD(uint64 _amountSD) internal view virtual returns (uint256 amountLD) {
        return _amountSD * decimalConversionRate;
    }
    /**
     * @dev Internal function to convert an amount from local decimals into shared decimals.
     * @param _amountLD The amount in local decimals.
     * @return amountSD The amount in shared decimals.
     */
    function _toSD(uint256 _amountLD) internal view virtual returns (uint64 amountSD) {
        return uint64(_amountLD / decimalConversionRate);
    }
    /**
     * @dev Internal function to mock the amount mutation from a OFT debit() operation.
     * @param _amountLD The amount to send in local decimals.
     * @param _minAmountLD The minimum amount to send in local decimals.
     * @dev _dstEid The destination endpoint ID.
     * @return amountSentLD The amount sent, in local decimals.
     * @return amountReceivedLD The amount to be received on the remote chain, in local decimals.
     *
     * @dev This is where things like fees would be calculated and deducted from the amount to be received on the remote.
     */
    function _debitView(
        uint256 _amountLD,
        uint256 _minAmountLD,
        uint32 /*_dstEid*/
    ) internal view virtual returns (uint256 amountSentLD, uint256 amountReceivedLD) {
        // @dev Remove the dust so nothing is lost on the conversion between chains with different decimals for the token.
        amountSentLD = _removeDust(_amountLD);
        // @dev The amount to send is the same as amount received in the default implementation.
        amountReceivedLD = amountSentLD;
        // @dev Check for slippage.
        if (amountReceivedLD < _minAmountLD) {
            revert SlippageExceeded(amountReceivedLD, _minAmountLD);
        }
    }
    /**
     * @dev Internal function to perform a debit operation.
     * @param _from The address to debit.
     * @param _amountLD The amount to send in local decimals.
     * @param _minAmountLD The minimum amount to send in local decimals.
     * @param _dstEid The destination endpoint ID.
     * @return amountSentLD The amount sent in local decimals.
     * @return amountReceivedLD The amount received in local decimals on the remote.
     *
     * @dev Defined here but are intended to be overriden depending on the OFT implementation.
     * @dev Depending on OFT implementation the _amountLD could differ from the amountReceivedLD.
     */
    function _debit(
        address _from,
        uint256 _amountLD,
        uint256 _minAmountLD,
        uint32 _dstEid
    ) internal virtual returns (uint256 amountSentLD, uint256 amountReceivedLD);
    /**
     * @dev Internal function to perform a credit operation.
     * @param _to The address to credit.
     * @param _amountLD The amount to credit in local decimals.
     * @param _srcEid The source endpoint ID.
     * @return amountReceivedLD The amount ACTUALLY received in local decimals.
     *
     * @dev Defined here but are intended to be overriden depending on the OFT implementation.
     * @dev Depending on OFT implementation the _amountLD could differ from the amountReceivedLD.
     */
    function _credit(
        address _to,
        uint256 _amountLD,
        uint32 _srcEid
    ) internal virtual returns (uint256 amountReceivedLD);
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.20;
import { MessagingReceipt, MessagingFee } from "@layerzerolabs/oapp-evm/contracts/oapp/OAppSender.sol";
/**
 * @dev Struct representing token parameters for the OFT send() operation.
 */
struct SendParam {
    uint32 dstEid; // Destination endpoint ID.
    bytes32 to; // Recipient address.
    uint256 amountLD; // Amount to send in local decimals.
    uint256 minAmountLD; // Minimum amount to send in local decimals.
    bytes extraOptions; // Additional options supplied by the caller to be used in the LayerZero message.
    bytes composeMsg; // The composed message for the send() operation.
    bytes oftCmd; // The OFT command to be executed, unused in default OFT implementations.
}
/**
 * @dev Struct representing OFT limit information.
 * @dev These amounts can change dynamically and are up the specific oft implementation.
 */
struct OFTLimit {
    uint256 minAmountLD; // Minimum amount in local decimals that can be sent to the recipient.
    uint256 maxAmountLD; // Maximum amount in local decimals that can be sent to the recipient.
}
/**
 * @dev Struct representing OFT receipt information.
 */
struct OFTReceipt {
    uint256 amountSentLD; // Amount of tokens ACTUALLY debited from the sender in local decimals.
    // @dev In non-default implementations, the amountReceivedLD COULD differ from this value.
    uint256 amountReceivedLD; // Amount of tokens to be received on the remote side.
}
/**
 * @dev Struct representing OFT fee details.
 * @dev Future proof mechanism to provide a standardized way to communicate fees to things like a UI.
 */
struct OFTFeeDetail {
    int256 feeAmountLD; // Amount of the fee in local decimals.
    string description; // Description of the fee.
}
/**
 * @title IOFT
 * @dev Interface for the OftChain (OFT) token.
 * @dev Does not inherit ERC20 to accommodate usage by OFTAdapter as well.
 * @dev This specific interface ID is '0x02e49c2c'.
 */
interface IOFT {
    // Custom error messages
    error InvalidLocalDecimals();
    error SlippageExceeded(uint256 amountLD, uint256 minAmountLD);
    // Events
    event OFTSent(
        bytes32 indexed guid, // GUID of the OFT message.
        uint32 dstEid, // Destination Endpoint ID.
        address indexed fromAddress, // Address of the sender on the src chain.
        uint256 amountSentLD, // Amount of tokens sent in local decimals.
        uint256 amountReceivedLD // Amount of tokens received in local decimals.
    );
    event OFTReceived(
        bytes32 indexed guid, // GUID of the OFT message.
        uint32 srcEid, // Source Endpoint ID.
        address indexed toAddress, // Address of the recipient on the dst chain.
        uint256 amountReceivedLD // Amount of tokens received in local decimals.
    );
    /**
     * @notice Retrieves interfaceID and the version of the OFT.
     * @return interfaceId The interface ID.
     * @return version The version.
     *
     * @dev interfaceId: This specific interface ID is '0x02e49c2c'.
     * @dev version: Indicates a cross-chain compatible msg encoding with other OFTs.
     * @dev If a new feature is added to the OFT cross-chain msg encoding, the version will be incremented.
     * ie. localOFT version(x,1) CAN send messages to remoteOFT version(x,1)
     */
    function oftVersion() external view returns (bytes4 interfaceId, uint64 version);
    /**
     * @notice Retrieves the address of the token associated with the OFT.
     * @return token The address of the ERC20 token implementation.
     */
    function token() external view returns (address);
    /**
     * @notice Indicates whether the OFT contract requires approval of the 'token()' to send.
     * @return requiresApproval Needs approval of the underlying token implementation.
     *
     * @dev Allows things like wallet implementers to determine integration requirements,
     * without understanding the underlying token implementation.
     */
    function approvalRequired() external view returns (bool);
    /**
     * @notice Retrieves the shared decimals of the OFT.
     * @return sharedDecimals The shared decimals of the OFT.
     */
    function sharedDecimals() external view returns (uint8);
    /**
     * @notice Provides the fee breakdown and settings data for an OFT. Unused in the default implementation.
     * @param _sendParam The parameters for the send operation.
     * @return limit The OFT limit information.
     * @return oftFeeDetails The details of OFT fees.
     * @return receipt The OFT receipt information.
     */
    function quoteOFT(
        SendParam calldata _sendParam
    ) external view returns (OFTLimit memory, OFTFeeDetail[] memory oftFeeDetails, OFTReceipt memory);
    /**
     * @notice Provides a quote for the send() operation.
     * @param _sendParam The parameters for the send() operation.
     * @param _payInLzToken Flag indicating whether the caller is paying in the LZ token.
     * @return fee The calculated LayerZero messaging fee from the send() operation.
     *
     * @dev MessagingFee: LayerZero msg fee
     *  - nativeFee: The native fee.
     *  - lzTokenFee: The lzToken fee.
     */
    function quoteSend(SendParam calldata _sendParam, bool _payInLzToken) external view returns (MessagingFee memory);
    /**
     * @notice Executes the send() operation.
     * @param _sendParam The parameters for the send operation.
     * @param _fee The fee information supplied by the caller.
     *      - nativeFee: The native fee.
     *      - lzTokenFee: The lzToken fee.
     * @param _refundAddress The address to receive any excess funds from fees etc. on the src.
     * @return receipt The LayerZero messaging receipt from the send() operation.
     * @return oftReceipt The OFT receipt information.
     *
     * @dev MessagingReceipt: LayerZero msg receipt
     *  - guid: The unique identifier for the sent message.
     *  - nonce: The nonce of the sent message.
     *  - fee: The LayerZero fee incurred for the message.
     */
    function send(
        SendParam calldata _sendParam,
        MessagingFee calldata _fee,
        address _refundAddress
    ) external payable returns (MessagingReceipt memory, OFTReceipt memory);
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.20;
library OFTComposeMsgCodec {
    // Offset constants for decoding composed messages
    uint8 private constant NONCE_OFFSET = 8;
    uint8 private constant SRC_EID_OFFSET = 12;
    uint8 private constant AMOUNT_LD_OFFSET = 44;
    uint8 private constant COMPOSE_FROM_OFFSET = 76;
    /**
     * @dev Encodes a OFT composed message.
     * @param _nonce The nonce value.
     * @param _srcEid The source endpoint ID.
     * @param _amountLD The amount in local decimals.
     * @param _composeMsg The composed message.
     * @return _msg The encoded Composed message.
     */
    function encode(
        uint64 _nonce,
        uint32 _srcEid,
        uint256 _amountLD,
        bytes memory _composeMsg // 0x[composeFrom][composeMsg]
    ) internal pure returns (bytes memory _msg) {
        _msg = abi.encodePacked(_nonce, _srcEid, _amountLD, _composeMsg);
    }
    /**
     * @dev Retrieves the nonce for the composed message.
     * @param _msg The message.
     * @return The nonce value.
     */
    function nonce(bytes calldata _msg) internal pure returns (uint64) {
        return uint64(bytes8(_msg[:NONCE_OFFSET]));
    }
    /**
     * @dev Retrieves the source endpoint ID for the composed message.
     * @param _msg The message.
     * @return The source endpoint ID.
     */
    function srcEid(bytes calldata _msg) internal pure returns (uint32) {
        return uint32(bytes4(_msg[NONCE_OFFSET:SRC_EID_OFFSET]));
    }
    /**
     * @dev Retrieves the amount in local decimals from the composed message.
     * @param _msg The message.
     * @return The amount in local decimals.
     */
    function amountLD(bytes calldata _msg) internal pure returns (uint256) {
        return uint256(bytes32(_msg[SRC_EID_OFFSET:AMOUNT_LD_OFFSET]));
    }
    /**
     * @dev Retrieves the composeFrom value from the composed message.
     * @param _msg The message.
     * @return The composeFrom value.
     */
    function composeFrom(bytes calldata _msg) internal pure returns (bytes32) {
        return bytes32(_msg[AMOUNT_LD_OFFSET:COMPOSE_FROM_OFFSET]);
    }
    /**
     * @dev Retrieves the composed message.
     * @param _msg The message.
     * @return The composed message.
     */
    function composeMsg(bytes calldata _msg) internal pure returns (bytes memory) {
        return _msg[COMPOSE_FROM_OFFSET:];
    }
    /**
     * @dev Converts an address to bytes32.
     * @param _addr The address to convert.
     * @return The bytes32 representation of the address.
     */
    function addressToBytes32(address _addr) internal pure returns (bytes32) {
        return bytes32(uint256(uint160(_addr)));
    }
    /**
     * @dev Converts bytes32 to an address.
     * @param _b The bytes32 value to convert.
     * @return The address representation of bytes32.
     */
    function bytes32ToAddress(bytes32 _b) internal pure returns (address) {
        return address(uint160(uint256(_b)));
    }
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.20;
library OFTMsgCodec {
    // Offset constants for encoding and decoding OFT messages
    uint8 private constant SEND_TO_OFFSET = 32;
    uint8 private constant SEND_AMOUNT_SD_OFFSET = 40;
    /**
     * @dev Encodes an OFT LayerZero message.
     * @param _sendTo The recipient address.
     * @param _amountShared The amount in shared decimals.
     * @param _composeMsg The composed message.
     * @return _msg The encoded message.
     * @return hasCompose A boolean indicating whether the message has a composed payload.
     */
    function encode(
        bytes32 _sendTo,
        uint64 _amountShared,
        bytes memory _composeMsg
    ) internal view returns (bytes memory _msg, bool hasCompose) {
        hasCompose = _composeMsg.length > 0;
        // @dev Remote chains will want to know the composed function caller ie. msg.sender on the src.
        _msg = hasCompose
            ? abi.encodePacked(_sendTo, _amountShared, addressToBytes32(msg.sender), _composeMsg)
            : abi.encodePacked(_sendTo, _amountShared);
    }
    /**
     * @dev Checks if the OFT message is composed.
     * @param _msg The OFT message.
     * @return A boolean indicating whether the message is composed.
     */
    function isComposed(bytes calldata _msg) internal pure returns (bool) {
        return _msg.length > SEND_AMOUNT_SD_OFFSET;
    }
    /**
     * @dev Retrieves the recipient address from the OFT message.
     * @param _msg The OFT message.
     * @return The recipient address.
     */
    function sendTo(bytes calldata _msg) internal pure returns (bytes32) {
        return bytes32(_msg[:SEND_TO_OFFSET]);
    }
    /**
     * @dev Retrieves the amount in shared decimals from the OFT message.
     * @param _msg The OFT message.
     * @return The amount in shared decimals.
     */
    function amountSD(bytes calldata _msg) internal pure returns (uint64) {
        return uint64(bytes8(_msg[SEND_TO_OFFSET:SEND_AMOUNT_SD_OFFSET]));
    }
    /**
     * @dev Retrieves the composed message from the OFT message.
     * @param _msg The OFT message.
     * @return The composed message.
     */
    function composeMsg(bytes calldata _msg) internal pure returns (bytes memory) {
        return _msg[SEND_AMOUNT_SD_OFFSET:];
    }
    /**
     * @dev Converts an address to bytes32.
     * @param _addr The address to convert.
     * @return The bytes32 representation of the address.
     */
    function addressToBytes32(address _addr) internal pure returns (bytes32) {
        return bytes32(uint256(uint160(_addr)));
    }
    /**
     * @dev Converts bytes32 to an address.
     * @param _b The bytes32 value to convert.
     * @return The address representation of bytes32.
     */
    function bytes32ToAddress(bytes32 _b) internal pure returns (address) {
        return address(uint160(uint256(_b)));
    }
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.0.0) (access/Ownable.sol)
pragma solidity ^0.8.20;
import {Context} from "../utils/Context.sol";
/**
 * @dev Contract module which provides a basic access control mechanism, where
 * there is an account (an owner) that can be granted exclusive access to
 * specific functions.
 *
 * The initial owner is set to the address provided by the deployer. This can
 * later be changed with {transferOwnership}.
 *
 * This module is used through inheritance. It will make available the modifier
 * `onlyOwner`, which can be applied to your functions to restrict their use to
 * the owner.
 */
abstract contract Ownable is Context {
    address private _owner;
    /**
     * @dev The caller account is not authorized to perform an operation.
     */
    error OwnableUnauthorizedAccount(address account);
    /**
     * @dev The owner is not a valid owner account. (eg. `address(0)`)
     */
    error OwnableInvalidOwner(address owner);
    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
    /**
     * @dev Initializes the contract setting the address provided by the deployer as the initial owner.
     */
    constructor(address initialOwner) {
        if (initialOwner == address(0)) {
            revert OwnableInvalidOwner(address(0));
        }
        _transferOwnership(initialOwner);
    }
    /**
     * @dev Throws if called by any account other than the owner.
     */
    modifier onlyOwner() {
        _checkOwner();
        _;
    }
    /**
     * @dev Returns the address of the current owner.
     */
    function owner() public view virtual returns (address) {
        return _owner;
    }
    /**
     * @dev Throws if the sender is not the owner.
     */
    function _checkOwner() internal view virtual {
        if (owner() != _msgSender()) {
            revert OwnableUnauthorizedAccount(_msgSender());
        }
    }
    /**
     * @dev Leaves the contract without owner. It will not be possible to call
     * `onlyOwner` functions. Can only be called by the current owner.
     *
     * NOTE: Renouncing ownership will leave the contract without an owner,
     * thereby disabling any functionality that is only available to the owner.
     */
    function renounceOwnership() public virtual onlyOwner {
        _transferOwnership(address(0));
    }
    /**
     * @dev Transfers ownership of the contract to a new account (`newOwner`).
     * Can only be called by the current owner.
     */
    function transferOwnership(address newOwner) public virtual onlyOwner {
        if (newOwner == address(0)) {
            revert OwnableInvalidOwner(address(0));
        }
        _transferOwnership(newOwner);
    }
    /**
     * @dev Transfers ownership of the contract to a new account (`newOwner`).
     * Internal function without access restriction.
     */
    function _transferOwnership(address newOwner) internal virtual {
        address oldOwner = _owner;
        _owner = newOwner;
        emit OwnershipTransferred(oldOwner, newOwner);
    }
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.1.0) (interfaces/IERC1363.sol)
pragma solidity ^0.8.20;
import {IERC20} from "./IERC20.sol";
import {IERC165} from "./IERC165.sol";
/**
 * @title IERC1363
 * @dev Interface of the ERC-1363 standard as defined in the https://eips.ethereum.org/EIPS/eip-1363[ERC-1363].
 *
 * Defines an extension interface for ERC-20 tokens that supports executing code on a recipient contract
 * after `transfer` or `transferFrom`, or code on a spender contract after `approve`, in a single transaction.
 */
interface IERC1363 is IERC20, IERC165 {
    /*
     * Note: the ERC-165 identifier for this interface is 0xb0202a11.
     * 0xb0202a11 ===
     *   bytes4(keccak256('transferAndCall(address,uint256)')) ^
     *   bytes4(keccak256('transferAndCall(address,uint256,bytes)')) ^
     *   bytes4(keccak256('transferFromAndCall(address,address,uint256)')) ^
     *   bytes4(keccak256('transferFromAndCall(address,address,uint256,bytes)')) ^
     *   bytes4(keccak256('approveAndCall(address,uint256)')) ^
     *   bytes4(keccak256('approveAndCall(address,uint256,bytes)'))
     */
    /**
     * @dev Moves a `value` amount of tokens from the caller's account to `to`
     * and then calls {IERC1363Receiver-onTransferReceived} on `to`.
     * @param to The address which you want to transfer to.
     * @param value The amount of tokens to be transferred.
     * @return A boolean value indicating whether the operation succeeded unless throwing.
     */
    function transferAndCall(address to, uint256 value) external returns (bool);
    /**
     * @dev Moves a `value` amount of tokens from the caller's account to `to`
     * and then calls {IERC1363Receiver-onTransferReceived} on `to`.
     * @param to The address which you want to transfer to.
     * @param value The amount of tokens to be transferred.
     * @param data Additional data with no specified format, sent in call to `to`.
     * @return A boolean value indicating whether the operation succeeded unless throwing.
     */
    function transferAndCall(address to, uint256 value, bytes calldata data) external returns (bool);
    /**
     * @dev Moves a `value` amount of tokens from `from` to `to` using the allowance mechanism
     * and then calls {IERC1363Receiver-onTransferReceived} on `to`.
     * @param from The address which you want to send tokens from.
     * @param to The address which you want to transfer to.
     * @param value The amount of tokens to be transferred.
     * @return A boolean value indicating whether the operation succeeded unless throwing.
     */
    function transferFromAndCall(address from, address to, uint256 value) external returns (bool);
    /**
     * @dev Moves a `value` amount of tokens from `from` to `to` using the allowance mechanism
     * and then calls {IERC1363Receiver-onTransferReceived} on `to`.
     * @param from The address which you want to send tokens from.
     * @param to The address which you want to transfer to.
     * @param value The amount of tokens to be transferred.
     * @param data Additional data with no specified format, sent in call to `to`.
     * @return A boolean value indicating whether the operation succeeded unless throwing.
     */
    function transferFromAndCall(address from, address to, uint256 value, bytes calldata data) external returns (bool);
    /**
     * @dev Sets a `value` amount of tokens as the allowance of `spender` over the
     * caller's tokens and then calls {IERC1363Spender-onApprovalReceived} on `spender`.
     * @param spender The address which will spend the funds.
     * @param value The amount of tokens to be spent.
     * @return A boolean value indicating whether the operation succeeded unless throwing.
     */
    function approveAndCall(address spender, uint256 value) external returns (bool);
    /**
     * @dev Sets a `value` amount of tokens as the allowance of `spender` over the
     * caller's tokens and then calls {IERC1363Spender-onApprovalReceived} on `spender`.
     * @param spender The address which will spend the funds.
     * @param value The amount of tokens to be spent.
     * @param data Additional data with no specified format, sent in call to `spender`.
     * @return A boolean value indicating whether the operation succeeded unless throwing.
     */
    function approveAndCall(address spender, uint256 value, bytes calldata data) external returns (bool);
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.0.0) (interfaces/IERC165.sol)
pragma solidity ^0.8.20;
import {IERC165} from "../utils/introspection/IERC165.sol";
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.0.0) (interfaces/IERC20.sol)
pragma solidity ^0.8.20;
import {IERC20} from "../token/ERC20/IERC20.sol";
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.1.0) (interfaces/draft-IERC6093.sol)
pragma solidity ^0.8.20;
/**
 * @dev Standard ERC-20 Errors
 * Interface of the https://eips.ethereum.org/EIPS/eip-6093[ERC-6093] custom errors for ERC-20 tokens.
 */
interface IERC20Errors {
    /**
     * @dev Indicates an error related to the current `balance` of a `sender`. Used in transfers.
     * @param sender Address whose tokens are being transferred.
     * @param balance Current balance for the interacting account.
     * @param needed Minimum amount required to perform a transfer.
     */
    error ERC20InsufficientBalance(address sender, uint256 balance, uint256 needed);
    /**
     * @dev Indicates a failure with the token `sender`. Used in transfers.
     * @param sender Address whose tokens are being transferred.
     */
    error ERC20InvalidSender(address sender);
    /**
     * @dev Indicates a failure with the token `receiver`. Used in transfers.
     * @param receiver Address to which tokens are being transferred.
     */
    error ERC20InvalidReceiver(address receiver);
    /**
     * @dev Indicates a failure with the `spender`’s `allowance`. Used in transfers.
     * @param spender Address that may be allowed to operate on tokens without being their owner.
     * @param allowance Amount of tokens a `spender` is allowed to operate with.
     * @param needed Minimum amount required to perform a transfer.
     */
    error ERC20InsufficientAllowance(address spender, uint256 allowance, uint256 needed);
    /**
     * @dev Indicates a failure with the `approver` of a token to be approved. Used in approvals.
     * @param approver Address initiating an approval operation.
     */
    error ERC20InvalidApprover(address approver);
    /**
     * @dev Indicates a failure with the `spender` to be approved. Used in approvals.
     * @param spender Address that may be allowed to operate on tokens without being their owner.
     */
    error ERC20InvalidSpender(address spender);
}
/**
 * @dev Standard ERC-721 Errors
 * Interface of the https://eips.ethereum.org/EIPS/eip-6093[ERC-6093] custom errors for ERC-721 tokens.
 */
interface IERC721Errors {
    /**
     * @dev Indicates that an address can't be an owner. For example, `address(0)` is a forbidden owner in ERC-20.
     * Used in balance queries.
     * @param owner Address of the current owner of a token.
     */
    error ERC721InvalidOwner(address owner);
    /**
     * @dev Indicates a `tokenId` whose `owner` is the zero address.
     * @param tokenId Identifier number of a token.
     */
    error ERC721NonexistentToken(uint256 tokenId);
    /**
     * @dev Indicates an error related to the ownership over a particular token. Used in transfers.
     * @param sender Address whose tokens are being transferred.
     * @param tokenId Identifier number of a token.
     * @param owner Address of the current owner of a token.
     */
    error ERC721IncorrectOwner(address sender, uint256 tokenId, address owner);
    /**
     * @dev Indicates a failure with the token `sender`. Used in transfers.
     * @param sender Address whose tokens are being transferred.
     */
    error ERC721InvalidSender(address sender);
    /**
     * @dev Indicates a failure with the token `receiver`. Used in transfers.
     * @param receiver Address to which tokens are being transferred.
     */
    error ERC721InvalidReceiver(address receiver);
    /**
     * @dev Indicates a failure with the `operator`’s approval. Used in transfers.
     * @param operator Address that may be allowed to operate on tokens without being their owner.
     * @param tokenId Identifier number of a token.
     */
    error ERC721InsufficientApproval(address operator, uint256 tokenId);
    /**
     * @dev Indicates a failure with the `approver` of a token to be approved. Used in approvals.
     * @param approver Address initiating an approval operation.
     */
    error ERC721InvalidApprover(address approver);
    /**
     * @dev Indicates a failure with the `operator` to be approved. Used in approvals.
     * @param operator Address that may be allowed to operate on tokens without being their owner.
     */
    error ERC721InvalidOperator(address operator);
}
/**
 * @dev Standard ERC-1155 Errors
 * Interface of the https://eips.ethereum.org/EIPS/eip-6093[ERC-6093] custom errors for ERC-1155 tokens.
 */
interface IERC1155Errors {
    /**
     * @dev Indicates an error related to the current `balance` of a `sender`. Used in transfers.
     * @param sender Address whose tokens are being transferred.
     * @param balance Current balance for the interacting account.
     * @param needed Minimum amount required to perform a transfer.
     * @param tokenId Identifier number of a token.
     */
    error ERC1155InsufficientBalance(address sender, uint256 balance, uint256 needed, uint256 tokenId);
    /**
     * @dev Indicates a failure with the token `sender`. Used in transfers.
     * @param sender Address whose tokens are being transferred.
     */
    error ERC1155InvalidSender(address sender);
    /**
     * @dev Indicates a failure with the token `receiver`. Used in transfers.
     * @param receiver Address to which tokens are being transferred.
     */
    error ERC1155InvalidReceiver(address receiver);
    /**
     * @dev Indicates a failure with the `operator`’s approval. Used in transfers.
     * @param operator Address that may be allowed to operate on tokens without being their owner.
     * @param owner Address of the current owner of a token.
     */
    error ERC1155MissingApprovalForAll(address operator, address owner);
    /**
     * @dev Indicates a failure with the `approver` of a token to be approved. Used in approvals.
     * @param approver Address initiating an approval operation.
     */
    error ERC1155InvalidApprover(address approver);
    /**
     * @dev Indicates a failure with the `operator` to be approved. Used in approvals.
     * @param operator Address that may be allowed to operate on tokens without being their owner.
     */
    error ERC1155InvalidOperator(address operator);
    /**
     * @dev Indicates an array length mismatch between ids and values in a safeBatchTransferFrom operation.
     * Used in batch transfers.
     * @param idsLength Length of the array of token identifiers
     * @param valuesLength Length of the array of token amounts
     */
    error ERC1155InvalidArrayLength(uint256 idsLength, uint256 valuesLength);
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.3.0) (token/ERC20/ERC20.sol)
pragma solidity ^0.8.20;
import {IERC20} from "./IERC20.sol";
import {IERC20Metadata} from "./extensions/IERC20Metadata.sol";
import {Context} from "../../utils/Context.sol";
import {IERC20Errors} from "../../interfaces/draft-IERC6093.sol";
/**
 * @dev Implementation of the {IERC20} interface.
 *
 * This implementation is agnostic to the way tokens are created. This means
 * that a supply mechanism has to be added in a derived contract using {_mint}.
 *
 * TIP: For a detailed writeup see our guide
 * https://forum.openzeppelin.com/t/how-to-implement-erc20-supply-mechanisms/226[How
 * to implement supply mechanisms].
 *
 * The default value of {decimals} is 18. To change this, you should override
 * this function so it returns a different value.
 *
 * We have followed general OpenZeppelin Contracts guidelines: functions revert
 * instead returning `false` on failure. This behavior is nonetheless
 * conventional and does not conflict with the expectations of ERC-20
 * applications.
 */
abstract contract ERC20 is Context, IERC20, IERC20Metadata, IERC20Errors {
    mapping(address account => uint256) private _balances;
    mapping(address account => mapping(address spender => uint256)) private _allowances;
    uint256 private _totalSupply;
    string private _name;
    string private _symbol;
    /**
     * @dev Sets the values for {name} and {symbol}.
     *
     * Both values are immutable: they can only be set once during construction.
     */
    constructor(string memory name_, string memory symbol_) {
        _name = name_;
        _symbol = symbol_;
    }
    /**
     * @dev Returns the name of the token.
     */
    function name() public view virtual returns (string memory) {
        return _name;
    }
    /**
     * @dev Returns the symbol of the token, usually a shorter version of the
     * name.
     */
    function symbol() public view virtual returns (string memory) {
        return _symbol;
    }
    /**
     * @dev Returns the number of decimals used to get its user representation.
     * For example, if `decimals` equals `2`, a balance of `505` tokens should
     * be displayed to a user as `5.05` (`505 / 10 ** 2`).
     *
     * Tokens usually opt for a value of 18, imitating the relationship between
     * Ether and Wei. This is the default value returned by this function, unless
     * it's overridden.
     *
     * NOTE: This information is only used for _display_ purposes: it in
     * no way affects any of the arithmetic of the contract, including
     * {IERC20-balanceOf} and {IERC20-transfer}.
     */
    function decimals() public view virtual returns (uint8) {
        return 18;
    }
    /**
     * @dev See {IERC20-totalSupply}.
     */
    function totalSupply() public view virtual returns (uint256) {
        return _totalSupply;
    }
    /**
     * @dev See {IERC20-balanceOf}.
     */
    function balanceOf(address account) public view virtual returns (uint256) {
        return _balances[account];
    }
    /**
     * @dev See {IERC20-transfer}.
     *
     * Requirements:
     *
     * - `to` cannot be the zero address.
     * - the caller must have a balance of at least `value`.
     */
    function transfer(address to, uint256 value) public virtual returns (bool) {
        address owner = _msgSender();
        _transfer(owner, to, value);
        return true;
    }
    /**
     * @dev See {IERC20-allowance}.
     */
    function allowance(address owner, address spender) public view virtual returns (uint256) {
        return _allowances[owner][spender];
    }
    /**
     * @dev See {IERC20-approve}.
     *
     * NOTE: If `value` is the maximum `uint256`, the allowance is not updated on
     * `transferFrom`. This is semantically equivalent to an infinite approval.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     */
    function approve(address spender, uint256 value) public virtual returns (bool) {
        address owner = _msgSender();
        _approve(owner, spender, value);
        return true;
    }
    /**
     * @dev See {IERC20-transferFrom}.
     *
     * Skips emitting an {Approval} event indicating an allowance update. This is not
     * required by the ERC. See {xref-ERC20-_approve-address-address-uint256-bool-}[_approve].
     *
     * NOTE: Does not update the allowance if the current allowance
     * is the maximum `uint256`.
     *
     * Requirements:
     *
     * - `from` and `to` cannot be the zero address.
     * - `from` must have a balance of at least `value`.
     * - the caller must have allowance for ``from``'s tokens of at least
     * `value`.
     */
    function transferFrom(address from, address to, uint256 value) public virtual returns (bool) {
        address spender = _msgSender();
        _spendAllowance(from, spender, value);
        _transfer(from, to, value);
        return true;
    }
    /**
     * @dev Moves a `value` amount of tokens from `from` to `to`.
     *
     * This internal function is equivalent to {transfer}, and can be used to
     * e.g. implement automatic token fees, slashing mechanisms, etc.
     *
     * Emits a {Transfer} event.
     *
     * NOTE: This function is not virtual, {_update} should be overridden instead.
     */
    function _transfer(address from, address to, uint256 value) internal {
        if (from == address(0)) {
            revert ERC20InvalidSender(address(0));
        }
        if (to == address(0)) {
            revert ERC20InvalidReceiver(address(0));
        }
        _update(from, to, value);
    }
    /**
     * @dev Transfers a `value` amount of tokens from `from` to `to`, or alternatively mints (or burns) if `from`
     * (or `to`) is the zero address. All customizations to transfers, mints, and burns should be done by overriding
     * this function.
     *
     * Emits a {Transfer} event.
     */
    function _update(address from, address to, uint256 value) internal virtual {
        if (from == address(0)) {
            // Overflow check required: The rest of the code assumes that totalSupply never overflows
            _totalSupply += value;
        } else {
            uint256 fromBalance = _balances[from];
            if (fromBalance < value) {
                revert ERC20InsufficientBalance(from, fromBalance, value);
            }
            unchecked {
                // Overflow not possible: value <= fromBalance <= totalSupply.
                _balances[from] = fromBalance - value;
            }
        }
        if (to == address(0)) {
            unchecked {
                // Overflow not possible: value <= totalSupply or value <= fromBalance <= totalSupply.
                _totalSupply -= value;
            }
        } else {
            unchecked {
                // Overflow not possible: balance + value is at most totalSupply, which we know fits into a uint256.
                _balances[to] += value;
            }
        }
        emit Transfer(from, to, value);
    }
    /**
     * @dev Creates a `value` amount of tokens and assigns them to `account`, by transferring it from address(0).
     * Relies on the `_update` mechanism
     *
     * Emits a {Transfer} event with `from` set to the zero address.
     *
     * NOTE: This function is not virtual, {_update} should be overridden instead.
     */
    function _mint(address account, uint256 value) internal {
        if (account == address(0)) {
            revert ERC20InvalidReceiver(address(0));
        }
        _update(address(0), account, value);
    }
    /**
     * @dev Destroys a `value` amount of tokens from `account`, lowering the total supply.
     * Relies on the `_update` mechanism.
     *
     * Emits a {Transfer} event with `to` set to the zero address.
     *
     * NOTE: This function is not virtual, {_update} should be overridden instead
     */
    function _burn(address account, uint256 value) internal {
        if (account == address(0)) {
            revert ERC20InvalidSender(address(0));
        }
        _update(account, address(0), value);
    }
    /**
     * @dev Sets `value` as the allowance of `spender` over the `owner`'s tokens.
     *
     * This internal function is equivalent to `approve`, and can be used to
     * e.g. set automatic allowances for certain subsystems, etc.
     *
     * Emits an {Approval} event.
     *
     * Requirements:
     *
     * - `owner` cannot be the zero address.
     * - `spender` cannot be the zero address.
     *
     * Overrides to this logic should be done to the variant with an additional `bool emitEvent` argument.
     */
    function _approve(address owner, address spender, uint256 value) internal {
        _approve(owner, spender, value, true);
    }
    /**
     * @dev Variant of {_approve} with an optional flag to enable or disable the {Approval} event.
     *
     * By default (when calling {_approve}) the flag is set to true. On the other hand, approval changes made by
     * `_spendAllowance` during the `transferFrom` operation set the flag to false. This saves gas by not emitting any
     * `Approval` event during `transferFrom` operations.
     *
     * Anyone who wishes to continue emitting `Approval` events on the`transferFrom` operation can force the flag to
     * true using the following override:
     *
     * ```solidity
     * function _approve(address owner, address spender, uint256 value, bool) internal virtual override {
     *     super._approve(owner, spender, value, true);
     * }
     * ```
     *
     * Requirements are the same as {_approve}.
     */
    function _approve(address owner, address spender, uint256 value, bool emitEvent) internal virtual {
        if (owner == address(0)) {
            revert ERC20InvalidApprover(address(0));
        }
        if (spender == address(0)) {
            revert ERC20InvalidSpender(address(0));
        }
        _allowances[owner][spender] = value;
        if (emitEvent) {
            emit Approval(owner, spender, value);
        }
    }
    /**
     * @dev Updates `owner`'s allowance for `spender` based on spent `value`.
     *
     * Does not update the allowance value in case of infinite allowance.
     * Revert if not enough allowance is available.
     *
     * Does not emit an {Approval} event.
     */
    function _spendAllowance(address owner, address spender, uint256 value) internal virtual {
        uint256 currentAllowance = allowance(owner, spender);
        if (currentAllowance < type(uint256).max) {
            if (currentAllowance < value) {
                revert ERC20InsufficientAllowance(spender, currentAllowance, value);
            }
            unchecked {
                _approve(owner, spender, currentAllowance - value, false);
            }
        }
    }
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.1.0) (token/ERC20/IERC20.sol)
pragma solidity ^0.8.20;
/**
 * @dev Interface of the ERC-20 standard as defined in the ERC.
 */
interface IERC20 {
    /**
     * @dev Emitted when `value` tokens are moved from one account (`from`) to
     * another (`to`).
     *
     * Note that `value` may be zero.
     */
    event Transfer(address indexed from, address indexed to, uint256 value);
    /**
     * @dev Emitted when the allowance of a `spender` for an `owner` is set by
     * a call to {approve}. `value` is the new allowance.
     */
    event Approval(address indexed owner, address indexed spender, uint256 value);
    /**
     * @dev Returns the value of tokens in existence.
     */
    function totalSupply() external view returns (uint256);
    /**
     * @dev Returns the value of tokens owned by `account`.
     */
    function balanceOf(address account) external view returns (uint256);
    /**
     * @dev Moves a `value` amount of tokens from the caller's account to `to`.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transfer(address to, uint256 value) external returns (bool);
    /**
     * @dev Returns the remaining number of tokens that `spender` will be
     * allowed to spend on behalf of `owner` through {transferFrom}. This is
     * zero by default.
     *
     * This value changes when {approve} or {transferFrom} are called.
     */
    function allowance(address owner, address spender) external view returns (uint256);
    /**
     * @dev Sets a `value` amount of tokens as the allowance of `spender` over the
     * caller's tokens.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * IMPORTANT: Beware that changing an allowance with this method brings the risk
     * that someone may use both the old and the new allowance by unfortunate
     * transaction ordering. One possible solution to mitigate this race
     * condition is to first reduce the spender's allowance to 0 and set the
     * desired value afterwards:
     * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
     *
     * Emits an {Approval} event.
     */
    function approve(address spender, uint256 value) external returns (bool);
    /**
     * @dev Moves a `value` amount of tokens from `from` to `to` using the
     * allowance mechanism. `value` is then deducted from the caller's
     * allowance.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transferFrom(address from, address to, uint256 value) external returns (bool);
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.1.0) (token/ERC20/extensions/IERC20Metadata.sol)
pragma solidity ^0.8.20;
import {IERC20} from "../IERC20.sol";
/**
 * @dev Interface for the optional metadata functions from the ERC-20 standard.
 */
interface IERC20Metadata is IERC20 {
    /**
     * @dev Returns the name of the token.
     */
    function name() external view returns (string memory);
    /**
     * @dev Returns the symbol of the token.
     */
    function symbol() external view returns (string memory);
    /**
     * @dev Returns the decimals places of the token.
     */
    function decimals() external view returns (uint8);
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.3.0) (token/ERC20/utils/SafeERC20.sol)
pragma solidity ^0.8.20;
import {IERC20} from "../IERC20.sol";
import {IERC1363} from "../../../interfaces/IERC1363.sol";
/**
 * @title SafeERC20
 * @dev Wrappers around ERC-20 operations that throw on failure (when the token
 * contract returns false). Tokens that return no value (and instead revert or
 * throw on failure) are also supported, non-reverting calls are assumed to be
 * successful.
 * To use this library you can add a `using SafeERC20 for IERC20;` statement to your contract,
 * which allows you to call the safe operations as `token.safeTransfer(...)`, etc.
 */
library SafeERC20 {
    /**
     * @dev An operation with an ERC-20 token failed.
     */
    error SafeERC20FailedOperation(address token);
    /**
     * @dev Indicates a failed `decreaseAllowance` request.
     */
    error SafeERC20FailedDecreaseAllowance(address spender, uint256 currentAllowance, uint256 requestedDecrease);
    /**
     * @dev Transfer `value` amount of `token` from the calling contract to `to`. If `token` returns no value,
     * non-reverting calls are assumed to be successful.
     */
    function safeTransfer(IERC20 token, address to, uint256 value) internal {
        _callOptionalReturn(token, abi.encodeCall(token.transfer, (to, value)));
    }
    /**
     * @dev Transfer `value` amount of `token` from `from` to `to`, spending the approval given by `from` to the
     * calling contract. If `token` returns no value, non-reverting calls are assumed to be successful.
     */
    function safeTransferFrom(IERC20 token, address from, address to, uint256 value) internal {
        _callOptionalReturn(token, abi.encodeCall(token.transferFrom, (from, to, value)));
    }
    /**
     * @dev Variant of {safeTransfer} that returns a bool instead of reverting if the operation is not successful.
     */
    function trySafeTransfer(IERC20 token, address to, uint256 value) internal returns (bool) {
        return _callOptionalReturnBool(token, abi.encodeCall(token.transfer, (to, value)));
    }
    /**
     * @dev Variant of {safeTransferFrom} that returns a bool instead of reverting if the operation is not successful.
     */
    function trySafeTransferFrom(IERC20 token, address from, address to, uint256 value) internal returns (bool) {
        return _callOptionalReturnBool(token, abi.encodeCall(token.transferFrom, (from, to, value)));
    }
    /**
     * @dev Increase the calling contract's allowance toward `spender` by `value`. If `token` returns no value,
     * non-reverting calls are assumed to be successful.
     *
     * IMPORTANT: If the token implements ERC-7674 (ERC-20 with temporary allowance), and if the "client"
     * smart contract uses ERC-7674 to set temporary allowances, then the "client" smart contract should avoid using
     * this function. Performing a {safeIncreaseAllowance} or {safeDecreaseAllowance} operation on a token contract
     * that has a non-zero temporary allowance (for that particular owner-spender) will result in unexpected behavior.
     */
    function safeIncreaseAllowance(IERC20 token, address spender, uint256 value) internal {
        uint256 oldAllowance = token.allowance(address(this), spender);
        forceApprove(token, spender, oldAllowance + value);
    }
    /**
     * @dev Decrease the calling contract's allowance toward `spender` by `requestedDecrease`. If `token` returns no
     * value, non-reverting calls are assumed to be successful.
     *
     * IMPORTANT: If the token implements ERC-7674 (ERC-20 with temporary allowance), and if the "client"
     * smart contract uses ERC-7674 to set temporary allowances, then the "client" smart contract should avoid using
     * this function. Performing a {safeIncreaseAllowance} or {safeDecreaseAllowance} operation on a token contract
     * that has a non-zero temporary allowance (for that particular owner-spender) will result in unexpected behavior.
     */
    function safeDecreaseAllowance(IERC20 token, address spender, uint256 requestedDecrease) internal {
        unchecked {
            uint256 currentAllowance = token.allowance(address(this), spender);
            if (currentAllowance < requestedDecrease) {
                revert SafeERC20FailedDecreaseAllowance(spender, currentAllowance, requestedDecrease);
            }
            forceApprove(token, spender, currentAllowance - requestedDecrease);
        }
    }
    /**
     * @dev Set the calling contract's allowance toward `spender` to `value`. If `token` returns no value,
     * non-reverting calls are assumed to be successful. Meant to be used with tokens that require the approval
     * to be set to zero before setting it to a non-zero value, such as USDT.
     *
     * NOTE: If the token implements ERC-7674, this function will not modify any temporary allowance. This function
     * only sets the "standard" allowance. Any temporary allowance will remain active, in addition to the value being
     * set here.
     */
    function forceApprove(IERC20 token, address spender, uint256 value) internal {
        bytes memory approvalCall = abi.encodeCall(token.approve, (spender, value));
        if (!_callOptionalReturnBool(token, approvalCall)) {
            _callOptionalReturn(token, abi.encodeCall(token.approve, (spender, 0)));
            _callOptionalReturn(token, approvalCall);
        }
    }
    /**
     * @dev Performs an {ERC1363} transferAndCall, with a fallback to the simple {ERC20} transfer if the target has no
     * code. This can be used to implement an {ERC721}-like safe transfer that rely on {ERC1363} checks when
     * targeting contracts.
     *
     * Reverts if the returned value is other than `true`.
     */
    function transferAndCallRelaxed(IERC1363 token, address to, uint256 value, bytes memory data) internal {
        if (to.code.length == 0) {
            safeTransfer(token, to, value);
        } else if (!token.transferAndCall(to, value, data)) {
            revert SafeERC20FailedOperation(address(token));
        }
    }
    /**
     * @dev Performs an {ERC1363} transferFromAndCall, with a fallback to the simple {ERC20} transferFrom if the target
     * has no code. This can be used to implement an {ERC721}-like safe transfer that rely on {ERC1363} checks when
     * targeting contracts.
     *
     * Reverts if the returned value is other than `true`.
     */
    function transferFromAndCallRelaxed(
        IERC1363 token,
        address from,
        address to,
        uint256 value,
        bytes memory data
    ) internal {
        if (to.code.length == 0) {
            safeTransferFrom(token, from, to, value);
        } else if (!token.transferFromAndCall(from, to, value, data)) {
            revert SafeERC20FailedOperation(address(token));
        }
    }
    /**
     * @dev Performs an {ERC1363} approveAndCall, with a fallback to the simple {ERC20} approve if the target has no
     * code. This can be used to implement an {ERC721}-like safe transfer that rely on {ERC1363} checks when
     * targeting contracts.
     *
     * NOTE: When the recipient address (`to`) has no code (i.e. is an EOA), this function behaves as {forceApprove}.
     * Opposedly, when the recipient address (`to`) has code, this function only attempts to call {ERC1363-approveAndCall}
     * once without retrying, and relies on the returned value to be true.
     *
     * Reverts if the returned value is other than `true`.
     */
    function approveAndCallRelaxed(IERC1363 token, address to, uint256 value, bytes memory data) internal {
        if (to.code.length == 0) {
            forceApprove(token, to, value);
        } else if (!token.approveAndCall(to, value, data)) {
            revert SafeERC20FailedOperation(address(token));
        }
    }
    /**
     * @dev Imitates a Solidity high-level call (i.e. a regular function call to a contract), relaxing the requirement
     * on the return value: the return value is optional (but if data is returned, it must not be false).
     * @param token The token targeted by the call.
     * @param data The call data (encoded using abi.encode or one of its variants).
     *
     * This is a variant of {_callOptionalReturnBool} that reverts if call fails to meet the requirements.
     */
    function _callOptionalReturn(IERC20 token, bytes memory data) private {
        uint256 returnSize;
        uint256 returnValue;
        assembly ("memory-safe") {
            let success := call(gas(), token, 0, add(data, 0x20), mload(data), 0, 0x20)
            // bubble errors
            if iszero(success) {
                let ptr := mload(0x40)
                returndatacopy(ptr, 0, returndatasize())
                revert(ptr, returndatasize())
            }
            returnSize := returndatasize()
            returnValue := mload(0)
        }
        if (returnSize == 0 ? address(token).code.length == 0 : returnValue != 1) {
            revert SafeERC20FailedOperation(address(token));
        }
    }
    /**
     * @dev Imitates a Solidity high-level call (i.e. a regular function call to a contract), relaxing the requirement
     * on the return value: the return value is optional (but if data is returned, it must not be false).
     * @param token The token targeted by the call.
     * @param data The call data (encoded using abi.encode or one of its variants).
     *
     * This is a variant of {_callOptionalReturn} that silently catches all reverts and returns a bool instead.
     */
    function _callOptionalReturnBool(IERC20 token, bytes memory data) private returns (bool) {
        bool success;
        uint256 returnSize;
        uint256 returnValue;
        assembly ("memory-safe") {
            success := call(gas(), token, 0, add(data, 0x20), mload(data), 0, 0x20)
            returnSize := returndatasize()
            returnValue := mload(0)
        }
        return success && (returnSize == 0 ? address(token).code.length > 0 : returnValue == 1);
    }
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.0.1) (utils/Context.sol)
pragma solidity ^0.8.20;
/**
 * @dev Provides information about the current execution context, including the
 * sender of the transaction and its data. While these are generally available
 * via msg.sender and msg.data, they should not be accessed in such a direct
 * manner, since when dealing with meta-transactions the account sending and
 * paying for execution may not be the actual sender (as far as an application
 * is concerned).
 *
 * This contract is only required for intermediate, library-like contracts.
 */
abstract contract Context {
    function _msgSender() internal view virtual returns (address) {
        return msg.sender;
    }
    function _msgData() internal view virtual returns (bytes calldata) {
        return msg.data;
    }
    function _contextSuffixLength() internal view virtual returns (uint256) {
        return 0;
    }
}
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.1.0) (utils/introspection/IERC165.sol)
pragma solidity ^0.8.20;
/**
 * @dev Interface of the ERC-165 standard, as defined in the
 * https://eips.ethereum.org/EIPS/eip-165[ERC].
 *
 * Implementers can declare support of contract interfaces, which can then be
 * queried by others ({ERC165Checker}).
 *
 * For an implementation, see {ERC165}.
 */
interface IERC165 {
    /**
     * @dev Returns true if this contract implements the interface defined by
     * `interfaceId`. See the corresponding
     * https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified[ERC section]
     * to learn more about how these ids are created.
     *
     * This function call must use less than 30 000 gas.
     */
    function supportsInterface(bytes4 interfaceId) external view returns (bool);
}
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.24;
/*
▗▄▄▄▖▗▖ ▗▖ ▗▄▖ ▗▄▄▖ ▗▖ ▗▖ ▗▄▖ 
  █  ▐▌ ▐▌▐▌ ▐▌▐▌ ▐▌▐▌ ▐▌▐▌ ▐▌
  █  ▐▛▀▜▌▐▛▀▜▌▐▛▀▚▖▐▌ ▐▌▐▛▀▜▌
  █  ▐▌ ▐▌▐▌ ▐▌▐▌ ▐▌▐▙█▟▌▐▌ ▐▌
visit : https://tharwa.finance                         
*/
import { Ownable } from "@openzeppelin/contracts/access/Ownable.sol";
import { OFT } from "@layerzerolabs/oft-evm/contracts/OFT.sol";
/**
 * @dev Interface for UniswapV2Factory to create trading pairs
 */
interface IUniswapV2Factory {
    function createPair(address tokenA, address tokenB) external returns (address pair);
}
/**
 * @dev Interface for UniswapV2Router02 to interact with the DEX
 */
interface IUniswapV2Router02 {
    function factory() external view returns (address);
    function WETH() external view returns (address);
    function addLiquidityETH(
        address token,
        uint256 amountTokenDesired,
        uint256 amountTokenMin,
        uint256 amountETHMin,
        address to,
        uint256 deadline
    ) external payable returns (uint256 amountToken, uint256 amountETH, uint256 liquidity);
}
/**
 * @title TRWA
 * @author Tharwa Finance
 * @notice LayerZero OFT (Omnichain Fungible Token) with launch-phase trading guards and configurable buy/sell taxes
 * @dev Extends LayerZero's OFT for cross-chain functionality and OpenZeppelin's Ownable for access control
 */
contract TRWA is Ownable, OFT {
    /* ─────────────── launch settings ─────────────── */
    /// Maximum token supply (10 billion tokens)
    uint256 public constant MAX_SUPPLY = 10_000_000_000 * 1e18;
    /// Maximum tax in basis points (10%)
    uint256 public constant MAX_TAX_BPS = 1_000;
    /// Tax calculation denominator (100% = 10,000 basis points)
    uint256 internal constant TAX_DENOMINATOR = 10_000;
    /// Treasury address that receives collected taxes
    address public treasury;
    /// Trading enabled flag - gates trading functionality
    bool public tradingOpen;
    /// Uniswap V2 pair address (set once via setPair)
    address public pair;
    /// Mapping of addresses exempt from taxes
    mapping(address => bool) public isFeeExempt;
    /// Buy tax in basis points (default 0%)
    uint16 public buyTaxBps = 0;
    /// Sell tax in basis points (default 0%)
    uint16 public sellTaxBps = 0;
    // errors
    /// Thrown when attempting to set tax above maximum allowed
    /// @param maxTaxBps Maximum allowed tax in basis points
    /// @param actualTaxBps Attempted tax value in basis points
    error MaxTaxBpsExceeded(uint256 maxTaxBps, uint256 actualTaxBps);
    /// @notice Thrown when providing zero address where not allowed
    error ZeroAddress();
    /// @notice Thrown when attempting to open trading when already open
    error TradingAlreadyOpen();
    /* ─────────────── constructor ─────────────── */
    /**
     * @notice Initializes the TRWA token contract
     * @dev Mints 70% of supply to contract for liquidity, 30% to treasury (reserved for airdrops, marketing, CEX listing, etc.)
     * @param name_ Token name
     * @param symbol_ Token symbol
     * @param lzEndpoint_ LayerZero endpoint address for cross-chain functionality
     * @param delegate_ Initial owner and OFT delegate address
     * @param treasury_ Treasury address to receive taxes and initial allocation
     */
    constructor(
        string memory name_,
        string memory symbol_,
        address lzEndpoint_,
        address delegate_,
        address treasury_
    ) OFT(name_, symbol_, lzEndpoint_, delegate_) Ownable(delegate_) {
        // self-mint 70% to the inital lp
        _mint(address(this), (MAX_SUPPLY * 70) / 100);
        // rest to treasury
        _mint(treasury_, (MAX_SUPPLY * 30) / 100);
        treasury = treasury_;
    }
    /* ─────────────── core fee / guard logic ─────────────── */
    /**
     * @notice Internal transfer function with tax logic
     * @dev Overrides OpenZeppelin's _update to implement taxes on buys/sells
     * @dev Applies taxes only on non-exempt addresses during trades with the pair
     * @param from Sender address
     * @param to Recipient address
     * @param amount Transfer amount
     */
    function _update(address from, address to, uint256 amount) internal override {
        // Apply launch‑phase checks only for normal transfers (not mint/burn) and non‑exempt wallets.
        if (from != address(0) && to != address(0) && !isFeeExempt[from] && !isFeeExempt[to]) {
            bool isBuy = from == pair;
            bool isSell = to == pair;
            // Calculate and collect fee
            uint256 fee = ((isBuy ? buyTaxBps : isSell ? sellTaxBps : 0) * amount) / TAX_DENOMINATOR;
            if (fee > 0) {
                super._update(from, treasury, fee);
                amount -= fee;
            }
        }
        // Final transfer
        super._update(from, to, amount);
    }
    /** admin ops **/
    /**
     * @notice Opens trading and creates Uniswap V2 liquidity pool
     * @dev Can only be called once. Uses the ETH sent to create initial liquidity
     * @dev Approves router, creates pair, adds liquidity, and enables trading
     */
    function openTrading() external payable onlyOwner {
        // setup router address
        address uniswapV2Router_ = 0x7a250d5630B4cF539739dF2C5dAcb4c659F2488D;
        // check if trading is already open
        if (tradingOpen) {
            revert TradingAlreadyOpen();
        }
        // create the uniswap pair and add liquidity
        IUniswapV2Router02 uniswapV2Router = IUniswapV2Router02(uniswapV2Router_);
        _approve(address(this), uniswapV2Router_, balanceOf(address(this)));
        address tokenPair = IUniswapV2Factory(uniswapV2Router.factory()).createPair(
            address(this),
            uniswapV2Router.WETH()
        );
        uniswapV2Router.addLiquidityETH{ value: msg.value }(
            address(this),
            balanceOf(address(this)),
            0,
            0,
            msg.sender,
            block.timestamp
        );
        tradingOpen = true;
        setPair(tokenPair);
    }
    /**
     * @notice Updates buy and sell tax rates
     * @dev Both values must not exceed MAX_TAX_BPS
     * @param buyBps New buy tax in basis points
     * @param sellBps New sell tax in basis points
     */
    function setTaxes(uint16 buyBps, uint16 sellBps) external onlyOwner {
        if (buyBps > MAX_TAX_BPS) {
            revert MaxTaxBpsExceeded(MAX_TAX_BPS, buyBps);
        }
        if (sellBps > MAX_TAX_BPS) {
            revert MaxTaxBpsExceeded(MAX_TAX_BPS, sellBps);
        }
        buyTaxBps = buyBps;
        sellTaxBps = sellBps;
    }
    /**
     * @notice Sets or removes fee exemption for an address
     * @param account Address to update fee exemption status
     * @param flag True to exempt from fees, false to remove exemption
     */
    function setFeeExempt(address account, bool flag) external onlyOwner {
        isFeeExempt[account] = flag;
    }
    /**
     * @notice Sets the Uniswap pair address for tax calculations
     * @dev Can be called by owner to update the pair address
     * @param _pair Address of the Uniswap V2 pair
     */
    function setPair(address _pair) public onlyOwner {
        if (_pair == address(0)) {
            revert ZeroAddress();
        }
        pair = _pair;
    }
}

pragma solidity =0.5.16;

interface IUniswapV2Factory {
    event PairCreated(address indexed token0, address indexed token1, address pair, uint);

    function feeTo() external view returns (address);
    function feeToSetter() external view returns (address);

    function getPair(address tokenA, address tokenB) external view returns (address pair);
    function allPairs(uint) external view returns (address pair);
    function allPairsLength() external view returns (uint);

    function createPair(address tokenA, address tokenB) external returns (address pair);

    function setFeeTo(address) external;
    function setFeeToSetter(address) external;
}

interface IUniswapV2Pair {
    event Approval(address indexed owner, address indexed spender, uint value);
    event Transfer(address indexed from, address indexed to, uint value);

    function name() external pure returns (string memory);
    function symbol() external pure returns (string memory);
    function decimals() external pure returns (uint8);
    function totalSupply() external view returns (uint);
    function balanceOf(address owner) external view returns (uint);
    function allowance(address owner, address spender) external view returns (uint);

    function approve(address spender, uint value) external returns (bool);
    function transfer(address to, uint value) external returns (bool);
    function transferFrom(address from, address to, uint value) external returns (bool);

    function DOMAIN_SEPARATOR() external view returns (bytes32);
    function PERMIT_TYPEHASH() external pure returns (bytes32);
    function nonces(address owner) external view returns (uint);

    function permit(address owner, address spender, uint value, uint deadline, uint8 v, bytes32 r, bytes32 s) external;

    event Mint(address indexed sender, uint amount0, uint amount1);
    event Burn(address indexed sender, uint amount0, uint amount1, address indexed to);
    event Swap(
        address indexed sender,
        uint amount0In,
        uint amount1In,
        uint amount0Out,
        uint amount1Out,
        address indexed to
    );
    event Sync(uint112 reserve0, uint112 reserve1);

    function MINIMUM_LIQUIDITY() external pure returns (uint);
    function factory() external view returns (address);
    function token0() external view returns (address);
    function token1() external view returns (address);
    function getReserves() external view returns (uint112 reserve0, uint112 reserve1, uint32 blockTimestampLast);
    function price0CumulativeLast() external view returns (uint);
    function price1CumulativeLast() external view returns (uint);
    function kLast() external view returns (uint);

    function mint(address to) external returns (uint liquidity);
    function burn(address to) external returns (uint amount0, uint amount1);
    function swap(uint amount0Out, uint amount1Out, address to, bytes calldata data) external;
    function skim(address to) external;
    function sync() external;

    function initialize(address, address) external;
}

interface IUniswapV2ERC20 {
    event Approval(address indexed owner, address indexed spender, uint value);
    event Transfer(address indexed from, address indexed to, uint value);

    function name() external pure returns (string memory);
    function symbol() external pure returns (string memory);
    function decimals() external pure returns (uint8);
    function totalSupply() external view returns (uint);
    function balanceOf(address owner) external view returns (uint);
    function allowance(address owner, address spender) external view returns (uint);

    function approve(address spender, uint value) external returns (bool);
    function transfer(address to, uint value) external returns (bool);
    function transferFrom(address from, address to, uint value) external returns (bool);

    function DOMAIN_SEPARATOR() external view returns (bytes32);
    function PERMIT_TYPEHASH() external pure returns (bytes32);
    function nonces(address owner) external view returns (uint);

    function permit(address owner, address spender, uint value, uint deadline, uint8 v, bytes32 r, bytes32 s) external;
}

interface IERC20 {
    event Approval(address indexed owner, address indexed spender, uint value);
    event Transfer(address indexed from, address indexed to, uint value);

    function name() external view returns (string memory);
    function symbol() external view returns (string memory);
    function decimals() external view returns (uint8);
    function totalSupply() external view returns (uint);
    function balanceOf(address owner) external view returns (uint);
    function allowance(address owner, address spender) external view returns (uint);

    function approve(address spender, uint value) external returns (bool);
    function transfer(address to, uint value) external returns (bool);
    function transferFrom(address from, address to, uint value) external returns (bool);
}

interface IUniswapV2Callee {
    function uniswapV2Call(address sender, uint amount0, uint amount1, bytes calldata data) external;
}

contract UniswapV2ERC20 is IUniswapV2ERC20 {
    using SafeMath for uint;

    string public constant name = 'Uniswap V2';
    string public constant symbol = 'UNI-V2';
    uint8 public constant decimals = 18;
    uint  public totalSupply;
    mapping(address => uint) public balanceOf;
    mapping(address => mapping(address => uint)) public allowance;

    bytes32 public DOMAIN_SEPARATOR;
    // keccak256("Permit(address owner,address spender,uint256 value,uint256 nonce,uint256 deadline)");
    bytes32 public constant PERMIT_TYPEHASH = 0x6e71edae12b1b97f4d1f60370fef10105fa2faae0126114a169c64845d6126c9;
    mapping(address => uint) public nonces;

    event Approval(address indexed owner, address indexed spender, uint value);
    event Transfer(address indexed from, address indexed to, uint value);

    constructor() public {
        uint chainId;
        assembly {
            chainId := chainid
        }
        DOMAIN_SEPARATOR = keccak256(
            abi.encode(
                keccak256('EIP712Domain(string name,string version,uint256 chainId,address verifyingContract)'),
                keccak256(bytes(name)),
                keccak256(bytes('1')),
                chainId,
                address(this)
            )
        );
    }

    function _mint(address to, uint value) internal {
        totalSupply = totalSupply.add(value);
        balanceOf[to] = balanceOf[to].add(value);
        emit Transfer(address(0), to, value);
    }

    function _burn(address from, uint value) internal {
        balanceOf[from] = balanceOf[from].sub(value);
        totalSupply = totalSupply.sub(value);
        emit Transfer(from, address(0), value);
    }

    function _approve(address owner, address spender, uint value) private {
        allowance[owner][spender] = value;
        emit Approval(owner, spender, value);
    }

    function _transfer(address from, address to, uint value) private {
        balanceOf[from] = balanceOf[from].sub(value);
        balanceOf[to] = balanceOf[to].add(value);
        emit Transfer(from, to, value);
    }

    function approve(address spender, uint value) external returns (bool) {
        _approve(msg.sender, spender, value);
        return true;
    }

    function transfer(address to, uint value) external returns (bool) {
        _transfer(msg.sender, to, value);
        return true;
    }

    function transferFrom(address from, address to, uint value) external returns (bool) {
        if (allowance[from][msg.sender] != uint(-1)) {
            allowance[from][msg.sender] = allowance[from][msg.sender].sub(value);
        }
        _transfer(from, to, value);
        return true;
    }

    function permit(address owner, address spender, uint value, uint deadline, uint8 v, bytes32 r, bytes32 s) external {
        require(deadline >= block.timestamp, 'UniswapV2: EXPIRED');
        bytes32 digest = keccak256(
            abi.encodePacked(
                '\x19\x01',
                DOMAIN_SEPARATOR,
                keccak256(abi.encode(PERMIT_TYPEHASH, owner, spender, value, nonces[owner]++, deadline))
            )
        );
        address recoveredAddress = ecrecover(digest, v, r, s);
        require(recoveredAddress != address(0) && recoveredAddress == owner, 'UniswapV2: INVALID_SIGNATURE');
        _approve(owner, spender, value);
    }
}

contract UniswapV2Pair is IUniswapV2Pair, UniswapV2ERC20 {
    using SafeMath  for uint;
    using UQ112x112 for uint224;

    uint public constant MINIMUM_LIQUIDITY = 10**3;
    bytes4 private constant SELECTOR = bytes4(keccak256(bytes('transfer(address,uint256)')));

    address public factory;
    address public token0;
    address public token1;

    uint112 private reserve0;           // uses single storage slot, accessible via getReserves
    uint112 private reserve1;           // uses single storage slot, accessible via getReserves
    uint32  private blockTimestampLast; // uses single storage slot, accessible via getReserves

    uint public price0CumulativeLast;
    uint public price1CumulativeLast;
    uint public kLast; // reserve0 * reserve1, as of immediately after the most recent liquidity event

    uint private unlocked = 1;
    modifier lock() {
        require(unlocked == 1, 'UniswapV2: LOCKED');
        unlocked = 0;
        _;
        unlocked = 1;
    }

    function getReserves() public view returns (uint112 _reserve0, uint112 _reserve1, uint32 _blockTimestampLast) {
        _reserve0 = reserve0;
        _reserve1 = reserve1;
        _blockTimestampLast = blockTimestampLast;
    }

    function _safeTransfer(address token, address to, uint value) private {
        (bool success, bytes memory data) = token.call(abi.encodeWithSelector(SELECTOR, to, value));
        require(success && (data.length == 0 || abi.decode(data, (bool))), 'UniswapV2: TRANSFER_FAILED');
    }

    event Mint(address indexed sender, uint amount0, uint amount1);
    event Burn(address indexed sender, uint amount0, uint amount1, address indexed to);
    event Swap(
        address indexed sender,
        uint amount0In,
        uint amount1In,
        uint amount0Out,
        uint amount1Out,
        address indexed to
    );
    event Sync(uint112 reserve0, uint112 reserve1);

    constructor() public {
        factory = msg.sender;
    }

    // called once by the factory at time of deployment
    function initialize(address _token0, address _token1) external {
        require(msg.sender == factory, 'UniswapV2: FORBIDDEN'); // sufficient check
        token0 = _token0;
        token1 = _token1;
    }

    // update reserves and, on the first call per block, price accumulators
    function _update(uint balance0, uint balance1, uint112 _reserve0, uint112 _reserve1) private {
        require(balance0 <= uint112(-1) && balance1 <= uint112(-1), 'UniswapV2: OVERFLOW');
        uint32 blockTimestamp = uint32(block.timestamp % 2**32);
        uint32 timeElapsed = blockTimestamp - blockTimestampLast; // overflow is desired
        if (timeElapsed > 0 && _reserve0 != 0 && _reserve1 != 0) {
            // * never overflows, and + overflow is desired
            price0CumulativeLast += uint(UQ112x112.encode(_reserve1).uqdiv(_reserve0)) * timeElapsed;
            price1CumulativeLast += uint(UQ112x112.encode(_reserve0).uqdiv(_reserve1)) * timeElapsed;
        }
        reserve0 = uint112(balance0);
        reserve1 = uint112(balance1);
        blockTimestampLast = blockTimestamp;
        emit Sync(reserve0, reserve1);
    }

    // if fee is on, mint liquidity equivalent to 1/6th of the growth in sqrt(k)
    function _mintFee(uint112 _reserve0, uint112 _reserve1) private returns (bool feeOn) {
        address feeTo = IUniswapV2Factory(factory).feeTo();
        feeOn = feeTo != address(0);
        uint _kLast = kLast; // gas savings
        if (feeOn) {
            if (_kLast != 0) {
                uint rootK = Math.sqrt(uint(_reserve0).mul(_reserve1));
                uint rootKLast = Math.sqrt(_kLast);
                if (rootK > rootKLast) {
                    uint numerator = totalSupply.mul(rootK.sub(rootKLast));
                    uint denominator = rootK.mul(5).add(rootKLast);
                    uint liquidity = numerator / denominator;
                    if (liquidity > 0) _mint(feeTo, liquidity);
                }
            }
        } else if (_kLast != 0) {
            kLast = 0;
        }
    }

    // this low-level function should be called from a contract which performs important safety checks
    function mint(address to) external lock returns (uint liquidity) {
        (uint112 _reserve0, uint112 _reserve1,) = getReserves(); // gas savings
        uint balance0 = IERC20(token0).balanceOf(address(this));
        uint balance1 = IERC20(token1).balanceOf(address(this));
        uint amount0 = balance0.sub(_reserve0);
        uint amount1 = balance1.sub(_reserve1);

        bool feeOn = _mintFee(_reserve0, _reserve1);
        uint _totalSupply = totalSupply; // gas savings, must be defined here since totalSupply can update in _mintFee
        if (_totalSupply == 0) {
            liquidity = Math.sqrt(amount0.mul(amount1)).sub(MINIMUM_LIQUIDITY);
           _mint(address(0), MINIMUM_LIQUIDITY); // permanently lock the first MINIMUM_LIQUIDITY tokens
        } else {
            liquidity = Math.min(amount0.mul(_totalSupply) / _reserve0, amount1.mul(_totalSupply) / _reserve1);
        }
        require(liquidity > 0, 'UniswapV2: INSUFFICIENT_LIQUIDITY_MINTED');
        _mint(to, liquidity);

        _update(balance0, balance1, _reserve0, _reserve1);
        if (feeOn) kLast = uint(reserve0).mul(reserve1); // reserve0 and reserve1 are up-to-date
        emit Mint(msg.sender, amount0, amount1);
    }

    // this low-level function should be called from a contract which performs important safety checks
    function burn(address to) external lock returns (uint amount0, uint amount1) {
        (uint112 _reserve0, uint112 _reserve1,) = getReserves(); // gas savings
        address _token0 = token0;                                // gas savings
        address _token1 = token1;                                // gas savings
        uint balance0 = IERC20(_token0).balanceOf(address(this));
        uint balance1 = IERC20(_token1).balanceOf(address(this));
        uint liquidity = balanceOf[address(this)];

        bool feeOn = _mintFee(_reserve0, _reserve1);
        uint _totalSupply = totalSupply; // gas savings, must be defined here since totalSupply can update in _mintFee
        amount0 = liquidity.mul(balance0) / _totalSupply; // using balances ensures pro-rata distribution
        amount1 = liquidity.mul(balance1) / _totalSupply; // using balances ensures pro-rata distribution
        require(amount0 > 0 && amount1 > 0, 'UniswapV2: INSUFFICIENT_LIQUIDITY_BURNED');
        _burn(address(this), liquidity);
        _safeTransfer(_token0, to, amount0);
        _safeTransfer(_token1, to, amount1);
        balance0 = IERC20(_token0).balanceOf(address(this));
        balance1 = IERC20(_token1).balanceOf(address(this));

        _update(balance0, balance1, _reserve0, _reserve1);
        if (feeOn) kLast = uint(reserve0).mul(reserve1); // reserve0 and reserve1 are up-to-date
        emit Burn(msg.sender, amount0, amount1, to);
    }

    // this low-level function should be called from a contract which performs important safety checks
    function swap(uint amount0Out, uint amount1Out, address to, bytes calldata data) external lock {
        require(amount0Out > 0 || amount1Out > 0, 'UniswapV2: INSUFFICIENT_OUTPUT_AMOUNT');
        (uint112 _reserve0, uint112 _reserve1,) = getReserves(); // gas savings
        require(amount0Out < _reserve0 && amount1Out < _reserve1, 'UniswapV2: INSUFFICIENT_LIQUIDITY');

        uint balance0;
        uint balance1;
        { // scope for _token{0,1}, avoids stack too deep errors
        address _token0 = token0;
        address _token1 = token1;
        require(to != _token0 && to != _token1, 'UniswapV2: INVALID_TO');
        if (amount0Out > 0) _safeTransfer(_token0, to, amount0Out); // optimistically transfer tokens
        if (amount1Out > 0) _safeTransfer(_token1, to, amount1Out); // optimistically transfer tokens
        if (data.length > 0) IUniswapV2Callee(to).uniswapV2Call(msg.sender, amount0Out, amount1Out, data);
        balance0 = IERC20(_token0).balanceOf(address(this));
        balance1 = IERC20(_token1).balanceOf(address(this));
        }
        uint amount0In = balance0 > _reserve0 - amount0Out ? balance0 - (_reserve0 - amount0Out) : 0;
        uint amount1In = balance1 > _reserve1 - amount1Out ? balance1 - (_reserve1 - amount1Out) : 0;
        require(amount0In > 0 || amount1In > 0, 'UniswapV2: INSUFFICIENT_INPUT_AMOUNT');
        { // scope for reserve{0,1}Adjusted, avoids stack too deep errors
        uint balance0Adjusted = balance0.mul(1000).sub(amount0In.mul(3));
        uint balance1Adjusted = balance1.mul(1000).sub(amount1In.mul(3));
        require(balance0Adjusted.mul(balance1Adjusted) >= uint(_reserve0).mul(_reserve1).mul(1000**2), 'UniswapV2: K');
        }

        _update(balance0, balance1, _reserve0, _reserve1);
        emit Swap(msg.sender, amount0In, amount1In, amount0Out, amount1Out, to);
    }

    // force balances to match reserves
    function skim(address to) external lock {
        address _token0 = token0; // gas savings
        address _token1 = token1; // gas savings
        _safeTransfer(_token0, to, IERC20(_token0).balanceOf(address(this)).sub(reserve0));
        _safeTransfer(_token1, to, IERC20(_token1).balanceOf(address(this)).sub(reserve1));
    }

    // force reserves to match balances
    function sync() external lock {
        _update(IERC20(token0).balanceOf(address(this)), IERC20(token1).balanceOf(address(this)), reserve0, reserve1);
    }
}

contract UniswapV2Factory is IUniswapV2Factory {
    address public feeTo;
    address public feeToSetter;

    mapping(address => mapping(address => address)) public getPair;
    address[] public allPairs;

    event PairCreated(address indexed token0, address indexed token1, address pair, uint);

    constructor(address _feeToSetter) public {
        feeToSetter = _feeToSetter;
    }

    function allPairsLength() external view returns (uint) {
        return allPairs.length;
    }

    function createPair(address tokenA, address tokenB) external returns (address pair) {
        require(tokenA != tokenB, 'UniswapV2: IDENTICAL_ADDRESSES');
        (address token0, address token1) = tokenA < tokenB ? (tokenA, tokenB) : (tokenB, tokenA);
        require(token0 != address(0), 'UniswapV2: ZERO_ADDRESS');
        require(getPair[token0][token1] == address(0), 'UniswapV2: PAIR_EXISTS'); // single check is sufficient
        bytes memory bytecode = type(UniswapV2Pair).creationCode;
        bytes32 salt = keccak256(abi.encodePacked(token0, token1));
        assembly {
            pair := create2(0, add(bytecode, 32), mload(bytecode), salt)
        }
        IUniswapV2Pair(pair).initialize(token0, token1);
        getPair[token0][token1] = pair;
        getPair[token1][token0] = pair; // populate mapping in the reverse direction
        allPairs.push(pair);
        emit PairCreated(token0, token1, pair, allPairs.length);
    }

    function setFeeTo(address _feeTo) external {
        require(msg.sender == feeToSetter, 'UniswapV2: FORBIDDEN');
        feeTo = _feeTo;
    }

    function setFeeToSetter(address _feeToSetter) external {
        require(msg.sender == feeToSetter, 'UniswapV2: FORBIDDEN');
        feeToSetter = _feeToSetter;
    }
}

// a library for performing overflow-safe math, courtesy of DappHub (https://github.com/dapphub/ds-math)

library SafeMath {
    function add(uint x, uint y) internal pure returns (uint z) {
        require((z = x + y) >= x, 'ds-math-add-overflow');
    }

    function sub(uint x, uint y) internal pure returns (uint z) {
        require((z = x - y) <= x, 'ds-math-sub-underflow');
    }

    function mul(uint x, uint y) internal pure returns (uint z) {
        require(y == 0 || (z = x * y) / y == x, 'ds-math-mul-overflow');
    }
}

// a library for performing various math operations

library Math {
    function min(uint x, uint y) internal pure returns (uint z) {
        z = x < y ? x : y;
    }

    // babylonian method (https://en.wikipedia.org/wiki/Methods_of_computing_square_roots#Babylonian_method)
    function sqrt(uint y) internal pure returns (uint z) {
        if (y > 3) {
            z = y;
            uint x = y / 2 + 1;
            while (x < z) {
                z = x;
                x = (y / x + x) / 2;
            }
        } else if (y != 0) {
            z = 1;
        }
    }
}

// a library for handling binary fixed point numbers (https://en.wikipedia.org/wiki/Q_(number_format))

// range: [0, 2**112 - 1]
// resolution: 1 / 2**112

library UQ112x112 {
    uint224 constant Q112 = 2**112;

    // encode a uint112 as a UQ112x112
    function encode(uint112 y) internal pure returns (uint224 z) {
        z = uint224(y) * Q112; // never overflows
    }

    // divide a UQ112x112 by a uint112, returning a UQ112x112
    function uqdiv(uint224 x, uint112 y) internal pure returns (uint224 z) {
        z = x / uint224(y);
    }
}

// File: contracts/interfaces/IUniswapV2Pair.sol

pragma solidity >=0.5.0;

interface IUniswapV2Pair {
    event Approval(address indexed owner, address indexed spender, uint value);
    event Transfer(address indexed from, address indexed to, uint value);

    function name() external pure returns (string memory);
    function symbol() external pure returns (string memory);
    function decimals() external pure returns (uint8);
    function totalSupply() external view returns (uint);
    function balanceOf(address owner) external view returns (uint);
    function allowance(address owner, address spender) external view returns (uint);

    function approve(address spender, uint value) external returns (bool);
    function transfer(address to, uint value) external returns (bool);
    function transferFrom(address from, address to, uint value) external returns (bool);

    function DOMAIN_SEPARATOR() external view returns (bytes32);
    function PERMIT_TYPEHASH() external pure returns (bytes32);
    function nonces(address owner) external view returns (uint);

    function permit(address owner, address spender, uint value, uint deadline, uint8 v, bytes32 r, bytes32 s) external;

    event Mint(address indexed sender, uint amount0, uint amount1);
    event Burn(address indexed sender, uint amount0, uint amount1, address indexed to);
    event Swap(
        address indexed sender,
        uint amount0In,
        uint amount1In,
        uint amount0Out,
        uint amount1Out,
        address indexed to
    );
    event Sync(uint112 reserve0, uint112 reserve1);

    function MINIMUM_LIQUIDITY() external pure returns (uint);
    function factory() external view returns (address);
    function token0() external view returns (address);
    function token1() external view returns (address);
    function getReserves() external view returns (uint112 reserve0, uint112 reserve1, uint32 blockTimestampLast);
    function price0CumulativeLast() external view returns (uint);
    function price1CumulativeLast() external view returns (uint);
    function kLast() external view returns (uint);

    function mint(address to) external returns (uint liquidity);
    function burn(address to) external returns (uint amount0, uint amount1);
    function swap(uint amount0Out, uint amount1Out, address to, bytes calldata data) external;
    function skim(address to) external;
    function sync() external;

    function initialize(address, address) external;
}

// File: contracts/interfaces/IUniswapV2ERC20.sol

pragma solidity >=0.5.0;

interface IUniswapV2ERC20 {
    event Approval(address indexed owner, address indexed spender, uint value);
    event Transfer(address indexed from, address indexed to, uint value);

    function name() external pure returns (string memory);
    function symbol() external pure returns (string memory);
    function decimals() external pure returns (uint8);
    function totalSupply() external view returns (uint);
    function balanceOf(address owner) external view returns (uint);
    function allowance(address owner, address spender) external view returns (uint);

    function approve(address spender, uint value) external returns (bool);
    function transfer(address to, uint value) external returns (bool);
    function transferFrom(address from, address to, uint value) external returns (bool);

    function DOMAIN_SEPARATOR() external view returns (bytes32);
    function PERMIT_TYPEHASH() external pure returns (bytes32);
    function nonces(address owner) external view returns (uint);

    function permit(address owner, address spender, uint value, uint deadline, uint8 v, bytes32 r, bytes32 s) external;
}

// File: contracts/libraries/SafeMath.sol

pragma solidity =0.5.16;

// a library for performing overflow-safe math, courtesy of DappHub (https://github.com/dapphub/ds-math)

library SafeMath {
    function add(uint x, uint y) internal pure returns (uint z) {
        require((z = x + y) >= x, 'ds-math-add-overflow');
    }

    function sub(uint x, uint y) internal pure returns (uint z) {
        require((z = x - y) <= x, 'ds-math-sub-underflow');
    }

    function mul(uint x, uint y) internal pure returns (uint z) {
        require(y == 0 || (z = x * y) / y == x, 'ds-math-mul-overflow');
    }
}

// File: contracts/UniswapV2ERC20.sol

pragma solidity =0.5.16;



contract UniswapV2ERC20 is IUniswapV2ERC20 {
    using SafeMath for uint;

    string public constant name = 'Uniswap V2';
    string public constant symbol = 'UNI-V2';
    uint8 public constant decimals = 18;
    uint  public totalSupply;
    mapping(address => uint) public balanceOf;
    mapping(address => mapping(address => uint)) public allowance;

    bytes32 public DOMAIN_SEPARATOR;
    // keccak256("Permit(address owner,address spender,uint256 value,uint256 nonce,uint256 deadline)");
    bytes32 public constant PERMIT_TYPEHASH = 0x6e71edae12b1b97f4d1f60370fef10105fa2faae0126114a169c64845d6126c9;
    mapping(address => uint) public nonces;

    event Approval(address indexed owner, address indexed spender, uint value);
    event Transfer(address indexed from, address indexed to, uint value);

    constructor() public {
        uint chainId;
        assembly {
            chainId := chainid
        }
        DOMAIN_SEPARATOR = keccak256(
            abi.encode(
                keccak256('EIP712Domain(string name,string version,uint256 chainId,address verifyingContract)'),
                keccak256(bytes(name)),
                keccak256(bytes('1')),
                chainId,
                address(this)
            )
        );
    }

    function _mint(address to, uint value) internal {
        totalSupply = totalSupply.add(value);
        balanceOf[to] = balanceOf[to].add(value);
        emit Transfer(address(0), to, value);
    }

    function _burn(address from, uint value) internal {
        balanceOf[from] = balanceOf[from].sub(value);
        totalSupply = totalSupply.sub(value);
        emit Transfer(from, address(0), value);
    }

    function _approve(address owner, address spender, uint value) private {
        allowance[owner][spender] = value;
        emit Approval(owner, spender, value);
    }

    function _transfer(address from, address to, uint value) private {
        balanceOf[from] = balanceOf[from].sub(value);
        balanceOf[to] = balanceOf[to].add(value);
        emit Transfer(from, to, value);
    }

    function approve(address spender, uint value) external returns (bool) {
        _approve(msg.sender, spender, value);
        return true;
    }

    function transfer(address to, uint value) external returns (bool) {
        _transfer(msg.sender, to, value);
        return true;
    }

    function transferFrom(address from, address to, uint value) external returns (bool) {
        if (allowance[from][msg.sender] != uint(-1)) {
            allowance[from][msg.sender] = allowance[from][msg.sender].sub(value);
        }
        _transfer(from, to, value);
        return true;
    }

    function permit(address owner, address spender, uint value, uint deadline, uint8 v, bytes32 r, bytes32 s) external {
        require(deadline >= block.timestamp, 'UniswapV2: EXPIRED');
        bytes32 digest = keccak256(
            abi.encodePacked(
                '\x19\x01',
                DOMAIN_SEPARATOR,
                keccak256(abi.encode(PERMIT_TYPEHASH, owner, spender, value, nonces[owner]++, deadline))
            )
        );
        address recoveredAddress = ecrecover(digest, v, r, s);
        require(recoveredAddress != address(0) && recoveredAddress == owner, 'UniswapV2: INVALID_SIGNATURE');
        _approve(owner, spender, value);
    }
}

// File: contracts/libraries/Math.sol

pragma solidity =0.5.16;

// a library for performing various math operations

library Math {
    function min(uint x, uint y) internal pure returns (uint z) {
        z = x < y ? x : y;
    }

    // babylonian method (https://en.wikipedia.org/wiki/Methods_of_computing_square_roots#Babylonian_method)
    function sqrt(uint y) internal pure returns (uint z) {
        if (y > 3) {
            z = y;
            uint x = y / 2 + 1;
            while (x < z) {
                z = x;
                x = (y / x + x) / 2;
            }
        } else if (y != 0) {
            z = 1;
        }
    }
}

// File: contracts/libraries/UQ112x112.sol

pragma solidity =0.5.16;

// a library for handling binary fixed point numbers (https://en.wikipedia.org/wiki/Q_(number_format))

// range: [0, 2**112 - 1]
// resolution: 1 / 2**112

library UQ112x112 {
    uint224 constant Q112 = 2**112;

    // encode a uint112 as a UQ112x112
    function encode(uint112 y) internal pure returns (uint224 z) {
        z = uint224(y) * Q112; // never overflows
    }

    // divide a UQ112x112 by a uint112, returning a UQ112x112
    function uqdiv(uint224 x, uint112 y) internal pure returns (uint224 z) {
        z = x / uint224(y);
    }
}

// File: contracts/interfaces/IERC20.sol

pragma solidity >=0.5.0;

interface IERC20 {
    event Approval(address indexed owner, address indexed spender, uint value);
    event Transfer(address indexed from, address indexed to, uint value);

    function name() external view returns (string memory);
    function symbol() external view returns (string memory);
    function decimals() external view returns (uint8);
    function totalSupply() external view returns (uint);
    function balanceOf(address owner) external view returns (uint);
    function allowance(address owner, address spender) external view returns (uint);

    function approve(address spender, uint value) external returns (bool);
    function transfer(address to, uint value) external returns (bool);
    function transferFrom(address from, address to, uint value) external returns (bool);
}

// File: contracts/interfaces/IUniswapV2Factory.sol

pragma solidity >=0.5.0;

interface IUniswapV2Factory {
    event PairCreated(address indexed token0, address indexed token1, address pair, uint);

    function feeTo() external view returns (address);
    function feeToSetter() external view returns (address);

    function getPair(address tokenA, address tokenB) external view returns (address pair);
    function allPairs(uint) external view returns (address pair);
    function allPairsLength() external view returns (uint);

    function createPair(address tokenA, address tokenB) external returns (address pair);

    function setFeeTo(address) external;
    function setFeeToSetter(address) external;
}

// File: contracts/interfaces/IUniswapV2Callee.sol

pragma solidity >=0.5.0;

interface IUniswapV2Callee {
    function uniswapV2Call(address sender, uint amount0, uint amount1, bytes calldata data) external;
}

// File: contracts/UniswapV2Pair.sol

pragma solidity =0.5.16;








contract UniswapV2Pair is IUniswapV2Pair, UniswapV2ERC20 {
    using SafeMath  for uint;
    using UQ112x112 for uint224;

    uint public constant MINIMUM_LIQUIDITY = 10**3;
    bytes4 private constant SELECTOR = bytes4(keccak256(bytes('transfer(address,uint256)')));

    address public factory;
    address public token0;
    address public token1;

    uint112 private reserve0;           // uses single storage slot, accessible via getReserves
    uint112 private reserve1;           // uses single storage slot, accessible via getReserves
    uint32  private blockTimestampLast; // uses single storage slot, accessible via getReserves

    uint public price0CumulativeLast;
    uint public price1CumulativeLast;
    uint public kLast; // reserve0 * reserve1, as of immediately after the most recent liquidity event

    uint private unlocked = 1;
    modifier lock() {
        require(unlocked == 1, 'UniswapV2: LOCKED');
        unlocked = 0;
        _;
        unlocked = 1;
    }

    function getReserves() public view returns (uint112 _reserve0, uint112 _reserve1, uint32 _blockTimestampLast) {
        _reserve0 = reserve0;
        _reserve1 = reserve1;
        _blockTimestampLast = blockTimestampLast;
    }

    function _safeTransfer(address token, address to, uint value) private {
        (bool success, bytes memory data) = token.call(abi.encodeWithSelector(SELECTOR, to, value));
        require(success && (data.length == 0 || abi.decode(data, (bool))), 'UniswapV2: TRANSFER_FAILED');
    }

    event Mint(address indexed sender, uint amount0, uint amount1);
    event Burn(address indexed sender, uint amount0, uint amount1, address indexed to);
    event Swap(
        address indexed sender,
        uint amount0In,
        uint amount1In,
        uint amount0Out,
        uint amount1Out,
        address indexed to
    );
    event Sync(uint112 reserve0, uint112 reserve1);

    constructor() public {
        factory = msg.sender;
    }

    // called once by the factory at time of deployment
    function initialize(address _token0, address _token1) external {
        require(msg.sender == factory, 'UniswapV2: FORBIDDEN'); // sufficient check
        token0 = _token0;
        token1 = _token1;
    }

    // update reserves and, on the first call per block, price accumulators
    function _update(uint balance0, uint balance1, uint112 _reserve0, uint112 _reserve1) private {
        require(balance0 <= uint112(-1) && balance1 <= uint112(-1), 'UniswapV2: OVERFLOW');
        uint32 blockTimestamp = uint32(block.timestamp % 2**32);
        uint32 timeElapsed = blockTimestamp - blockTimestampLast; // overflow is desired
        if (timeElapsed > 0 && _reserve0 != 0 && _reserve1 != 0) {
            // * never overflows, and + overflow is desired
            price0CumulativeLast += uint(UQ112x112.encode(_reserve1).uqdiv(_reserve0)) * timeElapsed;
            price1CumulativeLast += uint(UQ112x112.encode(_reserve0).uqdiv(_reserve1)) * timeElapsed;
        }
        reserve0 = uint112(balance0);
        reserve1 = uint112(balance1);
        blockTimestampLast = blockTimestamp;
        emit Sync(reserve0, reserve1);
    }

    // if fee is on, mint liquidity equivalent to 1/6th of the growth in sqrt(k)
    function _mintFee(uint112 _reserve0, uint112 _reserve1) private returns (bool feeOn) {
        address feeTo = IUniswapV2Factory(factory).feeTo();
        feeOn = feeTo != address(0);
        uint _kLast = kLast; // gas savings
        if (feeOn) {
            if (_kLast != 0) {
                uint rootK = Math.sqrt(uint(_reserve0).mul(_reserve1));
                uint rootKLast = Math.sqrt(_kLast);
                if (rootK > rootKLast) {
                    uint numerator = totalSupply.mul(rootK.sub(rootKLast));
                    uint denominator = rootK.mul(5).add(rootKLast);
                    uint liquidity = numerator / denominator;
                    if (liquidity > 0) _mint(feeTo, liquidity);
                }
            }
        } else if (_kLast != 0) {
            kLast = 0;
        }
    }

    // this low-level function should be called from a contract which performs important safety checks
    function mint(address to) external lock returns (uint liquidity) {
        (uint112 _reserve0, uint112 _reserve1,) = getReserves(); // gas savings
        uint balance0 = IERC20(token0).balanceOf(address(this));
        uint balance1 = IERC20(token1).balanceOf(address(this));
        uint amount0 = balance0.sub(_reserve0);
        uint amount1 = balance1.sub(_reserve1);

        bool feeOn = _mintFee(_reserve0, _reserve1);
        uint _totalSupply = totalSupply; // gas savings, must be defined here since totalSupply can update in _mintFee
        if (_totalSupply == 0) {
            liquidity = Math.sqrt(amount0.mul(amount1)).sub(MINIMUM_LIQUIDITY);
           _mint(address(0), MINIMUM_LIQUIDITY); // permanently lock the first MINIMUM_LIQUIDITY tokens
        } else {
            liquidity = Math.min(amount0.mul(_totalSupply) / _reserve0, amount1.mul(_totalSupply) / _reserve1);
        }
        require(liquidity > 0, 'UniswapV2: INSUFFICIENT_LIQUIDITY_MINTED');
        _mint(to, liquidity);

        _update(balance0, balance1, _reserve0, _reserve1);
        if (feeOn) kLast = uint(reserve0).mul(reserve1); // reserve0 and reserve1 are up-to-date
        emit Mint(msg.sender, amount0, amount1);
    }

    // this low-level function should be called from a contract which performs important safety checks
    function burn(address to) external lock returns (uint amount0, uint amount1) {
        (uint112 _reserve0, uint112 _reserve1,) = getReserves(); // gas savings
        address _token0 = token0;                                // gas savings
        address _token1 = token1;                                // gas savings
        uint balance0 = IERC20(_token0).balanceOf(address(this));
        uint balance1 = IERC20(_token1).balanceOf(address(this));
        uint liquidity = balanceOf[address(this)];

        bool feeOn = _mintFee(_reserve0, _reserve1);
        uint _totalSupply = totalSupply; // gas savings, must be defined here since totalSupply can update in _mintFee
        amount0 = liquidity.mul(balance0) / _totalSupply; // using balances ensures pro-rata distribution
        amount1 = liquidity.mul(balance1) / _totalSupply; // using balances ensures pro-rata distribution
        require(amount0 > 0 && amount1 > 0, 'UniswapV2: INSUFFICIENT_LIQUIDITY_BURNED');
        _burn(address(this), liquidity);
        _safeTransfer(_token0, to, amount0);
        _safeTransfer(_token1, to, amount1);
        balance0 = IERC20(_token0).balanceOf(address(this));
        balance1 = IERC20(_token1).balanceOf(address(this));

        _update(balance0, balance1, _reserve0, _reserve1);
        if (feeOn) kLast = uint(reserve0).mul(reserve1); // reserve0 and reserve1 are up-to-date
        emit Burn(msg.sender, amount0, amount1, to);
    }

    // this low-level function should be called from a contract which performs important safety checks
    function swap(uint amount0Out, uint amount1Out, address to, bytes calldata data) external lock {
        require(amount0Out > 0 || amount1Out > 0, 'UniswapV2: INSUFFICIENT_OUTPUT_AMOUNT');
        (uint112 _reserve0, uint112 _reserve1,) = getReserves(); // gas savings
        require(amount0Out < _reserve0 && amount1Out < _reserve1, 'UniswapV2: INSUFFICIENT_LIQUIDITY');

        uint balance0;
        uint balance1;
        { // scope for _token{0,1}, avoids stack too deep errors
        address _token0 = token0;
        address _token1 = token1;
        require(to != _token0 && to != _token1, 'UniswapV2: INVALID_TO');
        if (amount0Out > 0) _safeTransfer(_token0, to, amount0Out); // optimistically transfer tokens
        if (amount1Out > 0) _safeTransfer(_token1, to, amount1Out); // optimistically transfer tokens
        if (data.length > 0) IUniswapV2Callee(to).uniswapV2Call(msg.sender, amount0Out, amount1Out, data);
        balance0 = IERC20(_token0).balanceOf(address(this));
        balance1 = IERC20(_token1).balanceOf(address(this));
        }
        uint amount0In = balance0 > _reserve0 - amount0Out ? balance0 - (_reserve0 - amount0Out) : 0;
        uint amount1In = balance1 > _reserve1 - amount1Out ? balance1 - (_reserve1 - amount1Out) : 0;
        require(amount0In > 0 || amount1In > 0, 'UniswapV2: INSUFFICIENT_INPUT_AMOUNT');
        { // scope for reserve{0,1}Adjusted, avoids stack too deep errors
        uint balance0Adjusted = balance0.mul(1000).sub(amount0In.mul(3));
        uint balance1Adjusted = balance1.mul(1000).sub(amount1In.mul(3));
        require(balance0Adjusted.mul(balance1Adjusted) >= uint(_reserve0).mul(_reserve1).mul(1000**2), 'UniswapV2: K');
        }

        _update(balance0, balance1, _reserve0, _reserve1);
        emit Swap(msg.sender, amount0In, amount1In, amount0Out, amount1Out, to);
    }

    // force balances to match reserves
    function skim(address to) external lock {
        address _token0 = token0; // gas savings
        address _token1 = token1; // gas savings
        _safeTransfer(_token0, to, IERC20(_token0).balanceOf(address(this)).sub(reserve0));
        _safeTransfer(_token1, to, IERC20(_token1).balanceOf(address(this)).sub(reserve1));
    }

    // force reserves to match balances
    function sync() external lock {
        _update(IERC20(token0).balanceOf(address(this)), IERC20(token1).balanceOf(address(this)), reserve0, reserve1);
    }
}

// Copyright (C) 2015, 2016, 2017 Dapphub

// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.

// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.

// You should have received a copy of the GNU General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.

pragma solidity ^0.4.18;

contract WETH9 {
    string public name     = "Wrapped Ether";
    string public symbol   = "WETH";
    uint8  public decimals = 18;

    event  Approval(address indexed src, address indexed guy, uint wad);
    event  Transfer(address indexed src, address indexed dst, uint wad);
    event  Deposit(address indexed dst, uint wad);
    event  Withdrawal(address indexed src, uint wad);

    mapping (address => uint)                       public  balanceOf;
    mapping (address => mapping (address => uint))  public  allowance;

    function() public payable {
        deposit();
    }
    function deposit() public payable {
        balanceOf[msg.sender] += msg.value;
        Deposit(msg.sender, msg.value);
    }
    function withdraw(uint wad) public {
        require(balanceOf[msg.sender] >= wad);
        balanceOf[msg.sender] -= wad;
        msg.sender.transfer(wad);
        Withdrawal(msg.sender, wad);
    }

    function totalSupply() public view returns (uint) {
        return this.balance;
    }

    function approve(address guy, uint wad) public returns (bool) {
        allowance[msg.sender][guy] = wad;
        Approval(msg.sender, guy, wad);
        return true;
    }

    function transfer(address dst, uint wad) public returns (bool) {
        return transferFrom(msg.sender, dst, wad);
    }

    function transferFrom(address src, address dst, uint wad)
        public
        returns (bool)
    {
        require(balanceOf[src] >= wad);

        if (src != msg.sender && allowance[src][msg.sender] != uint(-1)) {
            require(allowance[src][msg.sender] >= wad);
            allowance[src][msg.sender] -= wad;
        }

        balanceOf[src] -= wad;
        balanceOf[dst] += wad;

        Transfer(src, dst, wad);

        return true;
    }
}


/*
                    GNU GENERAL PUBLIC LICENSE
                       Version 3, 29 June 2007

 Copyright (C) 2007 Free Software Foundation, Inc. <http://fsf.org/>
 Everyone is permitted to copy and distribute verbatim copies
 of this license document, but changing it is not allowed.

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            How to Apply These Terms to Your New Programs

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possible use to the public, the best way to achieve this is to make it
free software which everyone can redistribute and change under these terms.

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Also add information on how to contact you by electronic and paper mail.

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The hypothetical commands `show w' and `show c' should show the appropriate
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may consider it more useful to permit linking proprietary applications with
the library.  If this is what you want to do, use the GNU Lesser General
Public License instead of this License.  But first, please read
<http://www.gnu.org/philosophy/why-not-lgpl.html>.

*/

pragma solidity =0.6.6;

interface IUniswapV2Factory {
    event PairCreated(address indexed token0, address indexed token1, address pair, uint);

    function feeTo() external view returns (address);
    function feeToSetter() external view returns (address);

    function getPair(address tokenA, address tokenB) external view returns (address pair);
    function allPairs(uint) external view returns (address pair);
    function allPairsLength() external view returns (uint);

    function createPair(address tokenA, address tokenB) external returns (address pair);

    function setFeeTo(address) external;
    function setFeeToSetter(address) external;
}

interface IUniswapV2Pair {
    event Approval(address indexed owner, address indexed spender, uint value);
    event Transfer(address indexed from, address indexed to, uint value);

    function name() external pure returns (string memory);
    function symbol() external pure returns (string memory);
    function decimals() external pure returns (uint8);
    function totalSupply() external view returns (uint);
    function balanceOf(address owner) external view returns (uint);
    function allowance(address owner, address spender) external view returns (uint);

    function approve(address spender, uint value) external returns (bool);
    function transfer(address to, uint value) external returns (bool);
    function transferFrom(address from, address to, uint value) external returns (bool);

    function DOMAIN_SEPARATOR() external view returns (bytes32);
    function PERMIT_TYPEHASH() external pure returns (bytes32);
    function nonces(address owner) external view returns (uint);

    function permit(address owner, address spender, uint value, uint deadline, uint8 v, bytes32 r, bytes32 s) external;

    event Mint(address indexed sender, uint amount0, uint amount1);
    event Burn(address indexed sender, uint amount0, uint amount1, address indexed to);
    event Swap(
        address indexed sender,
        uint amount0In,
        uint amount1In,
        uint amount0Out,
        uint amount1Out,
        address indexed to
    );
    event Sync(uint112 reserve0, uint112 reserve1);

    function MINIMUM_LIQUIDITY() external pure returns (uint);
    function factory() external view returns (address);
    function token0() external view returns (address);
    function token1() external view returns (address);
    function getReserves() external view returns (uint112 reserve0, uint112 reserve1, uint32 blockTimestampLast);
    function price0CumulativeLast() external view returns (uint);
    function price1CumulativeLast() external view returns (uint);
    function kLast() external view returns (uint);

    function mint(address to) external returns (uint liquidity);
    function burn(address to) external returns (uint amount0, uint amount1);
    function swap(uint amount0Out, uint amount1Out, address to, bytes calldata data) external;
    function skim(address to) external;
    function sync() external;

    function initialize(address, address) external;
}

interface IUniswapV2Router01 {
    function factory() external pure returns (address);
    function WETH() external pure returns (address);

    function addLiquidity(
        address tokenA,
        address tokenB,
        uint amountADesired,
        uint amountBDesired,
        uint amountAMin,
        uint amountBMin,
        address to,
        uint deadline
    ) external returns (uint amountA, uint amountB, uint liquidity);
    function addLiquidityETH(
        address token,
        uint amountTokenDesired,
        uint amountTokenMin,
        uint amountETHMin,
        address to,
        uint deadline
    ) external payable returns (uint amountToken, uint amountETH, uint liquidity);
    function removeLiquidity(
        address tokenA,
        address tokenB,
        uint liquidity,
        uint amountAMin,
        uint amountBMin,
        address to,
        uint deadline
    ) external returns (uint amountA, uint amountB);
    function removeLiquidityETH(
        address token,
        uint liquidity,
        uint amountTokenMin,
        uint amountETHMin,
        address to,
        uint deadline
    ) external returns (uint amountToken, uint amountETH);
    function removeLiquidityWithPermit(
        address tokenA,
        address tokenB,
        uint liquidity,
        uint amountAMin,
        uint amountBMin,
        address to,
        uint deadline,
        bool approveMax, uint8 v, bytes32 r, bytes32 s
    ) external returns (uint amountA, uint amountB);
    function removeLiquidityETHWithPermit(
        address token,
        uint liquidity,
        uint amountTokenMin,
        uint amountETHMin,
        address to,
        uint deadline,
        bool approveMax, uint8 v, bytes32 r, bytes32 s
    ) external returns (uint amountToken, uint amountETH);
    function swapExactTokensForTokens(
        uint amountIn,
        uint amountOutMin,
        address[] calldata path,
        address to,
        uint deadline
    ) external returns (uint[] memory amounts);
    function swapTokensForExactTokens(
        uint amountOut,
        uint amountInMax,
        address[] calldata path,
        address to,
        uint deadline
    ) external returns (uint[] memory amounts);
    function swapExactETHForTokens(uint amountOutMin, address[] calldata path, address to, uint deadline)
        external
        payable
        returns (uint[] memory amounts);
    function swapTokensForExactETH(uint amountOut, uint amountInMax, address[] calldata path, address to, uint deadline)
        external
        returns (uint[] memory amounts);
    function swapExactTokensForETH(uint amountIn, uint amountOutMin, address[] calldata path, address to, uint deadline)
        external
        returns (uint[] memory amounts);
    function swapETHForExactTokens(uint amountOut, address[] calldata path, address to, uint deadline)
        external
        payable
        returns (uint[] memory amounts);

    function quote(uint amountA, uint reserveA, uint reserveB) external pure returns (uint amountB);
    function getAmountOut(uint amountIn, uint reserveIn, uint reserveOut) external pure returns (uint amountOut);
    function getAmountIn(uint amountOut, uint reserveIn, uint reserveOut) external pure returns (uint amountIn);
    function getAmountsOut(uint amountIn, address[] calldata path) external view returns (uint[] memory amounts);
    function getAmountsIn(uint amountOut, address[] calldata path) external view returns (uint[] memory amounts);
}

interface IUniswapV2Router02 is IUniswapV2Router01 {
    function removeLiquidityETHSupportingFeeOnTransferTokens(
        address token,
        uint liquidity,
        uint amountTokenMin,
        uint amountETHMin,
        address to,
        uint deadline
    ) external returns (uint amountETH);
    function removeLiquidityETHWithPermitSupportingFeeOnTransferTokens(
        address token,
        uint liquidity,
        uint amountTokenMin,
        uint amountETHMin,
        address to,
        uint deadline,
        bool approveMax, uint8 v, bytes32 r, bytes32 s
    ) external returns (uint amountETH);

    function swapExactTokensForTokensSupportingFeeOnTransferTokens(
        uint amountIn,
        uint amountOutMin,
        address[] calldata path,
        address to,
        uint deadline
    ) external;
    function swapExactETHForTokensSupportingFeeOnTransferTokens(
        uint amountOutMin,
        address[] calldata path,
        address to,
        uint deadline
    ) external payable;
    function swapExactTokensForETHSupportingFeeOnTransferTokens(
        uint amountIn,
        uint amountOutMin,
        address[] calldata path,
        address to,
        uint deadline
    ) external;
}

interface IERC20 {
    event Approval(address indexed owner, address indexed spender, uint value);
    event Transfer(address indexed from, address indexed to, uint value);

    function name() external view returns (string memory);
    function symbol() external view returns (string memory);
    function decimals() external view returns (uint8);
    function totalSupply() external view returns (uint);
    function balanceOf(address owner) external view returns (uint);
    function allowance(address owner, address spender) external view returns (uint);

    function approve(address spender, uint value) external returns (bool);
    function transfer(address to, uint value) external returns (bool);
    function transferFrom(address from, address to, uint value) external returns (bool);
}

interface IWETH {
    function deposit() external payable;
    function transfer(address to, uint value) external returns (bool);
    function withdraw(uint) external;
}

contract UniswapV2Router02 is IUniswapV2Router02 {
    using SafeMath for uint;

    address public immutable override factory;
    address public immutable override WETH;

    modifier ensure(uint deadline) {
        require(deadline >= block.timestamp, 'UniswapV2Router: EXPIRED');
        _;
    }

    constructor(address _factory, address _WETH) public {
        factory = _factory;
        WETH = _WETH;
    }

    receive() external payable {
        assert(msg.sender == WETH); // only accept ETH via fallback from the WETH contract
    }

    // **** ADD LIQUIDITY ****
    function _addLiquidity(
        address tokenA,
        address tokenB,
        uint amountADesired,
        uint amountBDesired,
        uint amountAMin,
        uint amountBMin
    ) internal virtual returns (uint amountA, uint amountB) {
        // create the pair if it doesn't exist yet
        if (IUniswapV2Factory(factory).getPair(tokenA, tokenB) == address(0)) {
            IUniswapV2Factory(factory).createPair(tokenA, tokenB);
        }
        (uint reserveA, uint reserveB) = UniswapV2Library.getReserves(factory, tokenA, tokenB);
        if (reserveA == 0 && reserveB == 0) {
            (amountA, amountB) = (amountADesired, amountBDesired);
        } else {
            uint amountBOptimal = UniswapV2Library.quote(amountADesired, reserveA, reserveB);
            if (amountBOptimal <= amountBDesired) {
                require(amountBOptimal >= amountBMin, 'UniswapV2Router: INSUFFICIENT_B_AMOUNT');
                (amountA, amountB) = (amountADesired, amountBOptimal);
            } else {
                uint amountAOptimal = UniswapV2Library.quote(amountBDesired, reserveB, reserveA);
                assert(amountAOptimal <= amountADesired);
                require(amountAOptimal >= amountAMin, 'UniswapV2Router: INSUFFICIENT_A_AMOUNT');
                (amountA, amountB) = (amountAOptimal, amountBDesired);
            }
        }
    }
    function addLiquidity(
        address tokenA,
        address tokenB,
        uint amountADesired,
        uint amountBDesired,
        uint amountAMin,
        uint amountBMin,
        address to,
        uint deadline
    ) external virtual override ensure(deadline) returns (uint amountA, uint amountB, uint liquidity) {
        (amountA, amountB) = _addLiquidity(tokenA, tokenB, amountADesired, amountBDesired, amountAMin, amountBMin);
        address pair = UniswapV2Library.pairFor(factory, tokenA, tokenB);
        TransferHelper.safeTransferFrom(tokenA, msg.sender, pair, amountA);
        TransferHelper.safeTransferFrom(tokenB, msg.sender, pair, amountB);
        liquidity = IUniswapV2Pair(pair).mint(to);
    }
    function addLiquidityETH(
        address token,
        uint amountTokenDesired,
        uint amountTokenMin,
        uint amountETHMin,
        address to,
        uint deadline
    ) external virtual override payable ensure(deadline) returns (uint amountToken, uint amountETH, uint liquidity) {
        (amountToken, amountETH) = _addLiquidity(
            token,
            WETH,
            amountTokenDesired,
            msg.value,
            amountTokenMin,
            amountETHMin
        );
        address pair = UniswapV2Library.pairFor(factory, token, WETH);
        TransferHelper.safeTransferFrom(token, msg.sender, pair, amountToken);
        IWETH(WETH).deposit{value: amountETH}();
        assert(IWETH(WETH).transfer(pair, amountETH));
        liquidity = IUniswapV2Pair(pair).mint(to);
        // refund dust eth, if any
        if (msg.value > amountETH) TransferHelper.safeTransferETH(msg.sender, msg.value - amountETH);
    }

    // **** REMOVE LIQUIDITY ****
    function removeLiquidity(
        address tokenA,
        address tokenB,
        uint liquidity,
        uint amountAMin,
        uint amountBMin,
        address to,
        uint deadline
    ) public virtual override ensure(deadline) returns (uint amountA, uint amountB) {
        address pair = UniswapV2Library.pairFor(factory, tokenA, tokenB);
        IUniswapV2Pair(pair).transferFrom(msg.sender, pair, liquidity); // send liquidity to pair
        (uint amount0, uint amount1) = IUniswapV2Pair(pair).burn(to);
        (address token0,) = UniswapV2Library.sortTokens(tokenA, tokenB);
        (amountA, amountB) = tokenA == token0 ? (amount0, amount1) : (amount1, amount0);
        require(amountA >= amountAMin, 'UniswapV2Router: INSUFFICIENT_A_AMOUNT');
        require(amountB >= amountBMin, 'UniswapV2Router: INSUFFICIENT_B_AMOUNT');
    }
    function removeLiquidityETH(
        address token,
        uint liquidity,
        uint amountTokenMin,
        uint amountETHMin,
        address to,
        uint deadline
    ) public virtual override ensure(deadline) returns (uint amountToken, uint amountETH) {
        (amountToken, amountETH) = removeLiquidity(
            token,
            WETH,
            liquidity,
            amountTokenMin,
            amountETHMin,
            address(this),
            deadline
        );
        TransferHelper.safeTransfer(token, to, amountToken);
        IWETH(WETH).withdraw(amountETH);
        TransferHelper.safeTransferETH(to, amountETH);
    }
    function removeLiquidityWithPermit(
        address tokenA,
        address tokenB,
        uint liquidity,
        uint amountAMin,
        uint amountBMin,
        address to,
        uint deadline,
        bool approveMax, uint8 v, bytes32 r, bytes32 s
    ) external virtual override returns (uint amountA, uint amountB) {
        address pair = UniswapV2Library.pairFor(factory, tokenA, tokenB);
        uint value = approveMax ? uint(-1) : liquidity;
        IUniswapV2Pair(pair).permit(msg.sender, address(this), value, deadline, v, r, s);
        (amountA, amountB) = removeLiquidity(tokenA, tokenB, liquidity, amountAMin, amountBMin, to, deadline);
    }
    function removeLiquidityETHWithPermit(
        address token,
        uint liquidity,
        uint amountTokenMin,
        uint amountETHMin,
        address to,
        uint deadline,
        bool approveMax, uint8 v, bytes32 r, bytes32 s
    ) external virtual override returns (uint amountToken, uint amountETH) {
        address pair = UniswapV2Library.pairFor(factory, token, WETH);
        uint value = approveMax ? uint(-1) : liquidity;
        IUniswapV2Pair(pair).permit(msg.sender, address(this), value, deadline, v, r, s);
        (amountToken, amountETH) = removeLiquidityETH(token, liquidity, amountTokenMin, amountETHMin, to, deadline);
    }

    // **** REMOVE LIQUIDITY (supporting fee-on-transfer tokens) ****
    function removeLiquidityETHSupportingFeeOnTransferTokens(
        address token,
        uint liquidity,
        uint amountTokenMin,
        uint amountETHMin,
        address to,
        uint deadline
    ) public virtual override ensure(deadline) returns (uint amountETH) {
        (, amountETH) = removeLiquidity(
            token,
            WETH,
            liquidity,
            amountTokenMin,
            amountETHMin,
            address(this),
            deadline
        );
        TransferHelper.safeTransfer(token, to, IERC20(token).balanceOf(address(this)));
        IWETH(WETH).withdraw(amountETH);
        TransferHelper.safeTransferETH(to, amountETH);
    }
    function removeLiquidityETHWithPermitSupportingFeeOnTransferTokens(
        address token,
        uint liquidity,
        uint amountTokenMin,
        uint amountETHMin,
        address to,
        uint deadline,
        bool approveMax, uint8 v, bytes32 r, bytes32 s
    ) external virtual override returns (uint amountETH) {
        address pair = UniswapV2Library.pairFor(factory, token, WETH);
        uint value = approveMax ? uint(-1) : liquidity;
        IUniswapV2Pair(pair).permit(msg.sender, address(this), value, deadline, v, r, s);
        amountETH = removeLiquidityETHSupportingFeeOnTransferTokens(
            token, liquidity, amountTokenMin, amountETHMin, to, deadline
        );
    }

    // **** SWAP ****
    // requires the initial amount to have already been sent to the first pair
    function _swap(uint[] memory amounts, address[] memory path, address _to) internal virtual {
        for (uint i; i < path.length - 1; i++) {
            (address input, address output) = (path[i], path[i + 1]);
            (address token0,) = UniswapV2Library.sortTokens(input, output);
            uint amountOut = amounts[i + 1];
            (uint amount0Out, uint amount1Out) = input == token0 ? (uint(0), amountOut) : (amountOut, uint(0));
            address to = i < path.length - 2 ? UniswapV2Library.pairFor(factory, output, path[i + 2]) : _to;
            IUniswapV2Pair(UniswapV2Library.pairFor(factory, input, output)).swap(
                amount0Out, amount1Out, to, new bytes(0)
            );
        }
    }
    function swapExactTokensForTokens(
        uint amountIn,
        uint amountOutMin,
        address[] calldata path,
        address to,
        uint deadline
    ) external virtual override ensure(deadline) returns (uint[] memory amounts) {
        amounts = UniswapV2Library.getAmountsOut(factory, amountIn, path);
        require(amounts[amounts.length - 1] >= amountOutMin, 'UniswapV2Router: INSUFFICIENT_OUTPUT_AMOUNT');
        TransferHelper.safeTransferFrom(
            path[0], msg.sender, UniswapV2Library.pairFor(factory, path[0], path[1]), amounts[0]
        );
        _swap(amounts, path, to);
    }
    function swapTokensForExactTokens(
        uint amountOut,
        uint amountInMax,
        address[] calldata path,
        address to,
        uint deadline
    ) external virtual override ensure(deadline) returns (uint[] memory amounts) {
        amounts = UniswapV2Library.getAmountsIn(factory, amountOut, path);
        require(amounts[0] <= amountInMax, 'UniswapV2Router: EXCESSIVE_INPUT_AMOUNT');
        TransferHelper.safeTransferFrom(
            path[0], msg.sender, UniswapV2Library.pairFor(factory, path[0], path[1]), amounts[0]
        );
        _swap(amounts, path, to);
    }
    function swapExactETHForTokens(uint amountOutMin, address[] calldata path, address to, uint deadline)
        external
        virtual
        override
        payable
        ensure(deadline)
        returns (uint[] memory amounts)
    {
        require(path[0] == WETH, 'UniswapV2Router: INVALID_PATH');
        amounts = UniswapV2Library.getAmountsOut(factory, msg.value, path);
        require(amounts[amounts.length - 1] >= amountOutMin, 'UniswapV2Router: INSUFFICIENT_OUTPUT_AMOUNT');
        IWETH(WETH).deposit{value: amounts[0]}();
        assert(IWETH(WETH).transfer(UniswapV2Library.pairFor(factory, path[0], path[1]), amounts[0]));
        _swap(amounts, path, to);
    }
    function swapTokensForExactETH(uint amountOut, uint amountInMax, address[] calldata path, address to, uint deadline)
        external
        virtual
        override
        ensure(deadline)
        returns (uint[] memory amounts)
    {
        require(path[path.length - 1] == WETH, 'UniswapV2Router: INVALID_PATH');
        amounts = UniswapV2Library.getAmountsIn(factory, amountOut, path);
        require(amounts[0] <= amountInMax, 'UniswapV2Router: EXCESSIVE_INPUT_AMOUNT');
        TransferHelper.safeTransferFrom(
            path[0], msg.sender, UniswapV2Library.pairFor(factory, path[0], path[1]), amounts[0]
        );
        _swap(amounts, path, address(this));
        IWETH(WETH).withdraw(amounts[amounts.length - 1]);
        TransferHelper.safeTransferETH(to, amounts[amounts.length - 1]);
    }
    function swapExactTokensForETH(uint amountIn, uint amountOutMin, address[] calldata path, address to, uint deadline)
        external
        virtual
        override
        ensure(deadline)
        returns (uint[] memory amounts)
    {
        require(path[path.length - 1] == WETH, 'UniswapV2Router: INVALID_PATH');
        amounts = UniswapV2Library.getAmountsOut(factory, amountIn, path);
        require(amounts[amounts.length - 1] >= amountOutMin, 'UniswapV2Router: INSUFFICIENT_OUTPUT_AMOUNT');
        TransferHelper.safeTransferFrom(
            path[0], msg.sender, UniswapV2Library.pairFor(factory, path[0], path[1]), amounts[0]
        );
        _swap(amounts, path, address(this));
        IWETH(WETH).withdraw(amounts[amounts.length - 1]);
        TransferHelper.safeTransferETH(to, amounts[amounts.length - 1]);
    }
    function swapETHForExactTokens(uint amountOut, address[] calldata path, address to, uint deadline)
        external
        virtual
        override
        payable
        ensure(deadline)
        returns (uint[] memory amounts)
    {
        require(path[0] == WETH, 'UniswapV2Router: INVALID_PATH');
        amounts = UniswapV2Library.getAmountsIn(factory, amountOut, path);
        require(amounts[0] <= msg.value, 'UniswapV2Router: EXCESSIVE_INPUT_AMOUNT');
        IWETH(WETH).deposit{value: amounts[0]}();
        assert(IWETH(WETH).transfer(UniswapV2Library.pairFor(factory, path[0], path[1]), amounts[0]));
        _swap(amounts, path, to);
        // refund dust eth, if any
        if (msg.value > amounts[0]) TransferHelper.safeTransferETH(msg.sender, msg.value - amounts[0]);
    }

    // **** SWAP (supporting fee-on-transfer tokens) ****
    // requires the initial amount to have already been sent to the first pair
    function _swapSupportingFeeOnTransferTokens(address[] memory path, address _to) internal virtual {
        for (uint i; i < path.length - 1; i++) {
            (address input, address output) = (path[i], path[i + 1]);
            (address token0,) = UniswapV2Library.sortTokens(input, output);
            IUniswapV2Pair pair = IUniswapV2Pair(UniswapV2Library.pairFor(factory, input, output));
            uint amountInput;
            uint amountOutput;
            { // scope to avoid stack too deep errors
            (uint reserve0, uint reserve1,) = pair.getReserves();
            (uint reserveInput, uint reserveOutput) = input == token0 ? (reserve0, reserve1) : (reserve1, reserve0);
            amountInput = IERC20(input).balanceOf(address(pair)).sub(reserveInput);
            amountOutput = UniswapV2Library.getAmountOut(amountInput, reserveInput, reserveOutput);
            }
            (uint amount0Out, uint amount1Out) = input == token0 ? (uint(0), amountOutput) : (amountOutput, uint(0));
            address to = i < path.length - 2 ? UniswapV2Library.pairFor(factory, output, path[i + 2]) : _to;
            pair.swap(amount0Out, amount1Out, to, new bytes(0));
        }
    }
    function swapExactTokensForTokensSupportingFeeOnTransferTokens(
        uint amountIn,
        uint amountOutMin,
        address[] calldata path,
        address to,
        uint deadline
    ) external virtual override ensure(deadline) {
        TransferHelper.safeTransferFrom(
            path[0], msg.sender, UniswapV2Library.pairFor(factory, path[0], path[1]), amountIn
        );
        uint balanceBefore = IERC20(path[path.length - 1]).balanceOf(to);
        _swapSupportingFeeOnTransferTokens(path, to);
        require(
            IERC20(path[path.length - 1]).balanceOf(to).sub(balanceBefore) >= amountOutMin,
            'UniswapV2Router: INSUFFICIENT_OUTPUT_AMOUNT'
        );
    }
    function swapExactETHForTokensSupportingFeeOnTransferTokens(
        uint amountOutMin,
        address[] calldata path,
        address to,
        uint deadline
    )
        external
        virtual
        override
        payable
        ensure(deadline)
    {
        require(path[0] == WETH, 'UniswapV2Router: INVALID_PATH');
        uint amountIn = msg.value;
        IWETH(WETH).deposit{value: amountIn}();
        assert(IWETH(WETH).transfer(UniswapV2Library.pairFor(factory, path[0], path[1]), amountIn));
        uint balanceBefore = IERC20(path[path.length - 1]).balanceOf(to);
        _swapSupportingFeeOnTransferTokens(path, to);
        require(
            IERC20(path[path.length - 1]).balanceOf(to).sub(balanceBefore) >= amountOutMin,
            'UniswapV2Router: INSUFFICIENT_OUTPUT_AMOUNT'
        );
    }
    function swapExactTokensForETHSupportingFeeOnTransferTokens(
        uint amountIn,
        uint amountOutMin,
        address[] calldata path,
        address to,
        uint deadline
    )
        external
        virtual
        override
        ensure(deadline)
    {
        require(path[path.length - 1] == WETH, 'UniswapV2Router: INVALID_PATH');
        TransferHelper.safeTransferFrom(
            path[0], msg.sender, UniswapV2Library.pairFor(factory, path[0], path[1]), amountIn
        );
        _swapSupportingFeeOnTransferTokens(path, address(this));
        uint amountOut = IERC20(WETH).balanceOf(address(this));
        require(amountOut >= amountOutMin, 'UniswapV2Router: INSUFFICIENT_OUTPUT_AMOUNT');
        IWETH(WETH).withdraw(amountOut);
        TransferHelper.safeTransferETH(to, amountOut);
    }

    // **** LIBRARY FUNCTIONS ****
    function quote(uint amountA, uint reserveA, uint reserveB) public pure virtual override returns (uint amountB) {
        return UniswapV2Library.quote(amountA, reserveA, reserveB);
    }

    function getAmountOut(uint amountIn, uint reserveIn, uint reserveOut)
        public
        pure
        virtual
        override
        returns (uint amountOut)
    {
        return UniswapV2Library.getAmountOut(amountIn, reserveIn, reserveOut);
    }

    function getAmountIn(uint amountOut, uint reserveIn, uint reserveOut)
        public
        pure
        virtual
        override
        returns (uint amountIn)
    {
        return UniswapV2Library.getAmountIn(amountOut, reserveIn, reserveOut);
    }

    function getAmountsOut(uint amountIn, address[] memory path)
        public
        view
        virtual
        override
        returns (uint[] memory amounts)
    {
        return UniswapV2Library.getAmountsOut(factory, amountIn, path);
    }

    function getAmountsIn(uint amountOut, address[] memory path)
        public
        view
        virtual
        override
        returns (uint[] memory amounts)
    {
        return UniswapV2Library.getAmountsIn(factory, amountOut, path);
    }
}

// a library for performing overflow-safe math, courtesy of DappHub (https://github.com/dapphub/ds-math)

library SafeMath {
    function add(uint x, uint y) internal pure returns (uint z) {
        require((z = x + y) >= x, 'ds-math-add-overflow');
    }

    function sub(uint x, uint y) internal pure returns (uint z) {
        require((z = x - y) <= x, 'ds-math-sub-underflow');
    }

    function mul(uint x, uint y) internal pure returns (uint z) {
        require(y == 0 || (z = x * y) / y == x, 'ds-math-mul-overflow');
    }
}

library UniswapV2Library {
    using SafeMath for uint;

    // returns sorted token addresses, used to handle return values from pairs sorted in this order
    function sortTokens(address tokenA, address tokenB) internal pure returns (address token0, address token1) {
        require(tokenA != tokenB, 'UniswapV2Library: IDENTICAL_ADDRESSES');
        (token0, token1) = tokenA < tokenB ? (tokenA, tokenB) : (tokenB, tokenA);
        require(token0 != address(0), 'UniswapV2Library: ZERO_ADDRESS');
    }

    // calculates the CREATE2 address for a pair without making any external calls
    function pairFor(address factory, address tokenA, address tokenB) internal pure returns (address pair) {
        (address token0, address token1) = sortTokens(tokenA, tokenB);
        pair = address(uint(keccak256(abi.encodePacked(
                hex'ff',
                factory,
                keccak256(abi.encodePacked(token0, token1)),
                hex'96e8ac4277198ff8b6f785478aa9a39f403cb768dd02cbee326c3e7da348845f' // init code hash
            ))));
    }

    // fetches and sorts the reserves for a pair
    function getReserves(address factory, address tokenA, address tokenB) internal view returns (uint reserveA, uint reserveB) {
        (address token0,) = sortTokens(tokenA, tokenB);
        (uint reserve0, uint reserve1,) = IUniswapV2Pair(pairFor(factory, tokenA, tokenB)).getReserves();
        (reserveA, reserveB) = tokenA == token0 ? (reserve0, reserve1) : (reserve1, reserve0);
    }

    // given some amount of an asset and pair reserves, returns an equivalent amount of the other asset
    function quote(uint amountA, uint reserveA, uint reserveB) internal pure returns (uint amountB) {
        require(amountA > 0, 'UniswapV2Library: INSUFFICIENT_AMOUNT');
        require(reserveA > 0 && reserveB > 0, 'UniswapV2Library: INSUFFICIENT_LIQUIDITY');
        amountB = amountA.mul(reserveB) / reserveA;
    }

    // given an input amount of an asset and pair reserves, returns the maximum output amount of the other asset
    function getAmountOut(uint amountIn, uint reserveIn, uint reserveOut) internal pure returns (uint amountOut) {
        require(amountIn > 0, 'UniswapV2Library: INSUFFICIENT_INPUT_AMOUNT');
        require(reserveIn > 0 && reserveOut > 0, 'UniswapV2Library: INSUFFICIENT_LIQUIDITY');
        uint amountInWithFee = amountIn.mul(997);
        uint numerator = amountInWithFee.mul(reserveOut);
        uint denominator = reserveIn.mul(1000).add(amountInWithFee);
        amountOut = numerator / denominator;
    }

    // given an output amount of an asset and pair reserves, returns a required input amount of the other asset
    function getAmountIn(uint amountOut, uint reserveIn, uint reserveOut) internal pure returns (uint amountIn) {
        require(amountOut > 0, 'UniswapV2Library: INSUFFICIENT_OUTPUT_AMOUNT');
        require(reserveIn > 0 && reserveOut > 0, 'UniswapV2Library: INSUFFICIENT_LIQUIDITY');
        uint numerator = reserveIn.mul(amountOut).mul(1000);
        uint denominator = reserveOut.sub(amountOut).mul(997);
        amountIn = (numerator / denominator).add(1);
    }

    // performs chained getAmountOut calculations on any number of pairs
    function getAmountsOut(address factory, uint amountIn, address[] memory path) internal view returns (uint[] memory amounts) {
        require(path.length >= 2, 'UniswapV2Library: INVALID_PATH');
        amounts = new uint[](path.length);
        amounts[0] = amountIn;
        for (uint i; i < path.length - 1; i++) {
            (uint reserveIn, uint reserveOut) = getReserves(factory, path[i], path[i + 1]);
            amounts[i + 1] = getAmountOut(amounts[i], reserveIn, reserveOut);
        }
    }

    // performs chained getAmountIn calculations on any number of pairs
    function getAmountsIn(address factory, uint amountOut, address[] memory path) internal view returns (uint[] memory amounts) {
        require(path.length >= 2, 'UniswapV2Library: INVALID_PATH');
        amounts = new uint[](path.length);
        amounts[amounts.length - 1] = amountOut;
        for (uint i = path.length - 1; i > 0; i--) {
            (uint reserveIn, uint reserveOut) = getReserves(factory, path[i - 1], path[i]);
            amounts[i - 1] = getAmountIn(amounts[i], reserveIn, reserveOut);
        }
    }
}

// helper methods for interacting with ERC20 tokens and sending ETH that do not consistently return true/false
library TransferHelper {
    function safeApprove(address token, address to, uint value) internal {
        // bytes4(keccak256(bytes('approve(address,uint256)')));
        (bool success, bytes memory data) = token.call(abi.encodeWithSelector(0x095ea7b3, to, value));
        require(success && (data.length == 0 || abi.decode(data, (bool))), 'TransferHelper: APPROVE_FAILED');
    }

    function safeTransfer(address token, address to, uint value) internal {
        // bytes4(keccak256(bytes('transfer(address,uint256)')));
        (bool success, bytes memory data) = token.call(abi.encodeWithSelector(0xa9059cbb, to, value));
        require(success && (data.length == 0 || abi.decode(data, (bool))), 'TransferHelper: TRANSFER_FAILED');
    }

    function safeTransferFrom(address token, address from, address to, uint value) internal {
        // bytes4(keccak256(bytes('transferFrom(address,address,uint256)')));
        (bool success, bytes memory data) = token.call(abi.encodeWithSelector(0x23b872dd, from, to, value));
        require(success && (data.length == 0 || abi.decode(data, (bool))), 'TransferHelper: TRANSFER_FROM_FAILED');
    }

    function safeTransferETH(address to, uint value) internal {
        (bool success,) = to.call{value:value}(new bytes(0));
        require(success, 'TransferHelper: ETH_TRANSFER_FAILED');
    }
}