ETH Price: $2,531.75 (-5.38%)

Transaction Decoder

Block:
18187600 at Sep-21-2023 11:43:47 PM +UTC
Transaction Fee:
0.00167672860808222 ETH $4.25
Gas Used:
186,802 Gas / 8.97596711 Gwei

Account State Difference:

  Address   Before After State Difference Code
0x2b79f42b...a4d89aa58
0.009319917025237072 Eth
Nonce: 2
0.007643188417154852 Eth
Nonce: 3
0.00167672860808222

Execution Trace

ETH 0.005780305657822948 WooCrossChainRouterV2.crossSwap( refId=347821695284564525, to=0x2b79f42b85B7312Bb4Cbe94f2a86dF6a4d89aa58, srcInfos=[{name:fromToken, type:address, order:1, indexed:false, value:0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE, valueString:0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE}, {name:bridgeToken, type:address, order:2, indexed:false, value:0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2, valueString:0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2}, {name:fromAmount, type:uint256, order:3, indexed:false, value:5000000000000000, valueString:5000000000000000}, {name:minBridgeAmount, type:uint256, order:4, indexed:false, value:5000000000000000, valueString:5000000000000000}], dstInfos=[{name:chainId, type:uint16, order:1, indexed:false, value:110, valueString:110}, {name:toToken, type:address, order:2, indexed:false, value:0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE, valueString:0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE}, {name:bridgeToken, type:address, order:3, indexed:false, value:0x82aF49447D8a07e3bd95BD0d56f35241523fBab1, valueString:0x82aF49447D8a07e3bd95BD0d56f35241523fBab1}, {name:minToAmount, type:uint256, order:4, indexed:false, value:4948020000000000, valueString:4948020000000000}, {name:airdropNativeAmount, type:uint256, order:5, indexed:false, value:0, valueString:0}] )
  • ETH 0.005 WETH9.CALL( )
  • WETH9.balanceOf( 0x9D1A92e601db0901e69bd810029F2C14bCCA3128 ) => ( 5000000000000000 )
  • WETH9.withdraw( wad=5000000000000000 )
    • ETH 0.005 WooCrossChainRouterV2.CALL( )
    • ETH 0.005 StargateEthVault.CALL( )
    • StargateEthVault.approve( guy=0x3b83D454A50aBe06d94cb0d5d367825e190bDA8F, wad=5000000000000000 ) => ( True )
    • ETH 0.000780305657822948 StargateComposer.swap( _dstChainId=110, _srcPoolId=13, _dstPoolId=13, _refundAddress=0x2b79f42b85B7312Bb4Cbe94f2a86dF6a4d89aa58, _amountLD=5000000000000000, _minAmountLD=4950000000000000, _lzTxParams=[{name:dstGasForCall, type:uint256, order:1, indexed:false, value:360000, valueString:360000}, {name:dstNativeAmount, type:uint256, order:2, indexed:false, value:0, valueString:0}, {name:dstNativeAddr, type:bytes, order:3, indexed:false, value:0x2B79F42B85B7312BB4CBE94F2A86DF6A4D89AA58, valueString:0x2B79F42B85B7312BB4CBE94F2A86DF6A4D89AA58}], _to=0x4AB421DE52B3112D02442B040DD3DC73E8AF63B5, _payload=0x00000000000000000000000000000000000000000000000004D3B5FD309C522D0000000000000000000000002B79F42B85B7312BB4CBE94F2A86DF6A4D89AA58000000000000000000000000EEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEE00000000000000000000000000000000000000000000000000119432AE710800 )
      crossSwap[WooCrossChainRouterV2 (ln:56)]
      File 1 of 4: WooCrossChainRouterV2
      // SPDX-License-Identifier: MIT
      pragma solidity =0.8.14;
      // OpenZeppelin Contracts
      import {IERC20} from "@openzeppelin/contracts/token/ERC20/IERC20.sol";
      import {Ownable} from "@openzeppelin/contracts/access/Ownable.sol";
      import {ReentrancyGuard} from "@openzeppelin/contracts/security/ReentrancyGuard.sol";
      import {EnumerableSet} from "@openzeppelin/contracts/utils/structs/EnumerableSet.sol";
      import {ICommonOFT, IOFTWithFee} from "@layerzerolabs/solidity-examples/contracts/token/oft/v2/fee/IOFTWithFee.sol";
      // Local Contracts
      import {IWETH} from "./interfaces/IWETH.sol";
      import {IWooCrossChainRouterV2} from "./interfaces/IWooCrossChainRouterV2.sol";
      import {IWooRouterV2} from "./interfaces/IWooRouterV2.sol";
      import {IStargateEthVault} from "./interfaces/Stargate/IStargateEthVault.sol";
      import {IStargateRouter} from "./interfaces/Stargate/IStargateRouter.sol";
      import {ILzApp} from "./interfaces/LayerZero/ILzApp.sol";
      import {TransferHelper} from "./libraries/TransferHelper.sol";
      /// @title WOOFi cross chain router implementation.
      /// @notice Router for stateless execution of cross chain swap against WOOFi private pool.
      /// @custom:stargate-contracts https://stargateprotocol.gitbook.io/stargate/developers/contract-addresses/mainnet
      contract WooCrossChainRouterV2 is IWooCrossChainRouterV2, Ownable, ReentrancyGuard {
          using EnumerableSet for EnumerableSet.AddressSet;
          /* ----- Constants ----- */
          address public constant ETH_PLACEHOLDER_ADDR = 0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE;
          /* ----- Variables ----- */
          IWooRouterV2 public wooRouter;
          IStargateRouter public stargateRouter;
          address public immutable weth;
          uint256 public bridgeSlippage; // 1 in 10000th: default 1%
          uint256 public dstGasForSwapCall;
          uint256 public dstGasForNoSwapCall;
          uint16 public sgChainIdLocal; // Stargate chainId on local chain
          mapping(uint16 => address) public wooCrossChainRouters; // chainId => WooCrossChainRouter address
          mapping(uint16 => address) public sgETHs; // chainId => SGETH token address
          mapping(uint16 => mapping(address => uint256)) public sgPoolIds; // chainId => token address => Stargate poolId
          mapping(address => address) public tokenToOFTs; // token address(sgChainIdLocal) => OFT address
          EnumerableSet.AddressSet private directBridgeTokens;
          receive() external payable {}
          constructor(
              address _weth,
              address _wooRouter,
              address _stargateRouter,
              uint16 _sgChainIdLocal
          ) {
              wooRouter = IWooRouterV2(_wooRouter);
              stargateRouter = IStargateRouter(_stargateRouter);
              weth = _weth;
              bridgeSlippage = 100;
              dstGasForSwapCall = 360000;
              dstGasForNoSwapCall = 80000;
              sgChainIdLocal = _sgChainIdLocal;
              _initSgETHs();
              _initSgPoolIds();
              _initTokenToOFTs(_sgChainIdLocal);
          }
          /* ----- Functions ----- */
          function crossSwap(
              uint256 refId,
              address payable to,
              SrcInfos memory srcInfos,
              DstInfos memory dstInfos
          ) external payable nonReentrant {
              require(srcInfos.fromToken != address(0), "WooCrossChainRouterV2: !srcInfos.fromToken");
              require(
                  dstInfos.toToken != address(0) && dstInfos.toToken != sgETHs[dstInfos.chainId],
                  "WooCrossChainRouterV2: !dstInfos.toToken"
              );
              require(to != address(0), "WooCrossChainRouterV2: !to");
              uint256 msgValue = msg.value;
              uint256 bridgeAmount;
              {
                  // Step 1: transfer
                  if (srcInfos.fromToken == ETH_PLACEHOLDER_ADDR) {
                      require(srcInfos.fromAmount <= msgValue, "WooCrossChainRouterV2: !srcInfos.fromAmount");
                      srcInfos.fromToken = weth;
                      IWETH(weth).deposit{value: srcInfos.fromAmount}();
                      msgValue -= srcInfos.fromAmount;
                  } else {
                      TransferHelper.safeTransferFrom(srcInfos.fromToken, msg.sender, address(this), srcInfos.fromAmount);
                  }
                  // Step 2: local swap by WooRouter or not
                  // 1.WOO is directBridgeToken, path(always) WOO(Arbitrum) => WOO(BSC)
                  // 2.WOO not the directBridgeToken, path(maybe): WOO(Arbitrum) -> USDC(Arbitrum) => BUSD(BSC) -> WOO(BSC)
                  // 3.Ethereum no WOOFi liquidity, tokens(WOO, ETH, USDC) always will be bridged directly without swap
                  if (!directBridgeTokens.contains(srcInfos.fromToken) && srcInfos.fromToken != srcInfos.bridgeToken) {
                      TransferHelper.safeApprove(srcInfos.fromToken, address(wooRouter), srcInfos.fromAmount);
                      bridgeAmount = wooRouter.swap(
                          srcInfos.fromToken,
                          srcInfos.bridgeToken,
                          srcInfos.fromAmount,
                          srcInfos.minBridgeAmount,
                          payable(address(this)),
                          to
                      );
                  } else {
                      require(
                          srcInfos.fromAmount == srcInfos.minBridgeAmount,
                          "WooCrossChainRouterV2: !srcInfos.minBridgeAmount"
                      );
                      bridgeAmount = srcInfos.fromAmount;
                  }
                  require(
                      bridgeAmount <= IERC20(srcInfos.bridgeToken).balanceOf(address(this)),
                      "WooCrossChainRouterV2: !bridgeAmount"
                  );
              }
              // Step 3: cross chain swap by [OFT / StargateRouter]
              address oft = tokenToOFTs[srcInfos.bridgeToken];
              if (oft != address(0)) {
                  _bridgeByOFT(refId, to, msgValue, bridgeAmount, IOFTWithFee(oft), srcInfos, dstInfos);
              } else {
                  _bridgeByStargate(refId, to, msgValue, bridgeAmount, srcInfos, dstInfos);
              }
              emit WooCrossSwapOnSrcChain(
                  refId,
                  _msgSender(),
                  to,
                  srcInfos.fromToken,
                  srcInfos.fromAmount,
                  srcInfos.minBridgeAmount,
                  bridgeAmount
              );
          }
          function onOFTReceived(
              uint16 srcChainId,
              bytes memory, // srcAddress
              uint64, // nonce
              bytes32 from,
              uint256 amountLD,
              bytes memory payload
          ) external {
              require(_isLegitOFT(_msgSender()), "WooCrossChainRouterV2: INVALID_CALLER");
              require(
                  wooCrossChainRouters[srcChainId] == address(uint160(uint256(from))),
                  "WooCrossChainRouterV2: INVALID_FROM"
              );
              // _msgSender() should be OFT address if requires above are passed
              address bridgedToken = IOFTWithFee(_msgSender()).token();
              // make sure the same order to abi.encode when decode payload
              (uint256 refId, address to, address toToken, uint256 minToAmount) = abi.decode(
                  payload,
                  (uint256, address, address, uint256)
              );
              _handleERC20Received(refId, to, toToken, bridgedToken, amountLD, minToAmount);
          }
          function sgReceive(
              uint16, // srcChainId
              bytes memory, // srcAddress
              uint256, // nonce
              address bridgedToken,
              uint256 amountLD,
              bytes memory payload
          ) external {
              require(msg.sender == address(stargateRouter), "WooCrossChainRouterV2: INVALID_CALLER");
              // make sure the same order to abi.encode when decode payload
              (uint256 refId, address to, address toToken, uint256 minToAmount) = abi.decode(
                  payload,
                  (uint256, address, address, uint256)
              );
              // toToken won't be SGETH, and bridgedToken won't be ETH_PLACEHOLDER_ADDR
              if (bridgedToken == sgETHs[sgChainIdLocal]) {
                  // bridgedToken is SGETH, received native token
                  _handleNativeReceived(refId, to, toToken, amountLD, minToAmount);
              } else {
                  // bridgedToken is not SGETH, received ERC20 token
                  _handleERC20Received(refId, to, toToken, bridgedToken, amountLD, minToAmount);
              }
          }
          function quoteLayerZeroFee(
              uint256 refId,
              address to,
              SrcInfos memory srcInfos,
              DstInfos memory dstInfos
          ) external view returns (uint256, uint256) {
              bytes memory payload = abi.encode(refId, to, dstInfos.toToken, dstInfos.minToAmount);
              address oft = tokenToOFTs[srcInfos.bridgeToken];
              if (oft != address(0)) {
                  // bridge via OFT if it's OFT
                  uint256 dstGasForCall = _getDstGasForCall(dstInfos);
                  bytes memory adapterParams = _getAdapterParams(to, oft, dstGasForCall, dstInfos);
                  bool useZro = false;
                  bytes32 dstWooCrossChainRouter = bytes32(uint256(uint160(wooCrossChainRouters[dstInfos.chainId])));
                  return
                      IOFTWithFee(oft).estimateSendAndCallFee(
                          dstInfos.chainId,
                          dstWooCrossChainRouter,
                          srcInfos.minBridgeAmount,
                          payload,
                          uint64(dstGasForCall),
                          useZro,
                          adapterParams
                      );
              } else {
                  // otherwise bridge via Stargate
                  IStargateRouter.lzTxObj memory obj = _getLzTxObj(to, dstInfos);
                  return
                      stargateRouter.quoteLayerZeroFee(
                          dstInfos.chainId,
                          1, // https://stargateprotocol.gitbook.io/stargate/developers/function-types
                          obj.dstNativeAddr,
                          payload,
                          obj
                      );
              }
          }
          function allDirectBridgeTokens() external view returns (address[] memory) {
              uint256 length = directBridgeTokens.length();
              address[] memory tokens = new address[](length);
              unchecked {
                  for (uint256 i = 0; i < length; ++i) {
                      tokens[i] = directBridgeTokens.at(i);
                  }
              }
              return tokens;
          }
          function allDirectBridgeTokensLength() external view returns (uint256) {
              return directBridgeTokens.length();
          }
          function _initSgETHs() internal {
              // Ethereum
              sgETHs[101] = 0x72E2F4830b9E45d52F80aC08CB2bEC0FeF72eD9c;
              // Arbitrum
              sgETHs[110] = 0x82CbeCF39bEe528B5476FE6d1550af59a9dB6Fc0;
              // Optimism
              sgETHs[111] = 0xb69c8CBCD90A39D8D3d3ccf0a3E968511C3856A0;
          }
          function _initSgPoolIds() internal {
              // poolId > 0 means able to be bridge token
              // Ethereum
              sgPoolIds[101][0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48] = 1; // USDC
              sgPoolIds[101][0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2] = 13; // WETH
              sgPoolIds[101][0x4691937a7508860F876c9c0a2a617E7d9E945D4B] = 20; // WOO
              // BNB Chain
              sgPoolIds[102][0x55d398326f99059fF775485246999027B3197955] = 2; // USDT
              sgPoolIds[102][0xe9e7CEA3DedcA5984780Bafc599bD69ADd087D56] = 5; // BUSD
              sgPoolIds[102][0x4691937a7508860F876c9c0a2a617E7d9E945D4B] = 20; // WOO
              // Avalanche
              sgPoolIds[106][0xB97EF9Ef8734C71904D8002F8b6Bc66Dd9c48a6E] = 1; // USDC
              sgPoolIds[106][0x9702230A8Ea53601f5cD2dc00fDBc13d4dF4A8c7] = 2; // USDT
              sgPoolIds[106][0xaBC9547B534519fF73921b1FBA6E672b5f58D083] = 20; // WOO
              // Polygon
              sgPoolIds[109][0x2791Bca1f2de4661ED88A30C99A7a9449Aa84174] = 1; // USDC
              sgPoolIds[109][0xc2132D05D31c914a87C6611C10748AEb04B58e8F] = 2; // USDT
              sgPoolIds[109][0x1B815d120B3eF02039Ee11dC2d33DE7aA4a8C603] = 20; // WOO
              // Arbitrum
              sgPoolIds[110][0xFF970A61A04b1cA14834A43f5dE4533eBDDB5CC8] = 1; // USDC
              sgPoolIds[110][0xFd086bC7CD5C481DCC9C85ebE478A1C0b69FCbb9] = 2; // USDT
              sgPoolIds[110][0x82aF49447D8a07e3bd95BD0d56f35241523fBab1] = 13; // WETH
              sgPoolIds[110][0xcAFcD85D8ca7Ad1e1C6F82F651fA15E33AEfD07b] = 20; // WOO
              // Optimism
              sgPoolIds[111][0x7F5c764cBc14f9669B88837ca1490cCa17c31607] = 1; // USDC
              sgPoolIds[111][0x4200000000000000000000000000000000000006] = 13; // WETH
              sgPoolIds[111][0x871f2F2ff935FD1eD867842FF2a7bfD051A5E527] = 20; // WOO
              // Fantom
              sgPoolIds[112][0x04068DA6C83AFCFA0e13ba15A6696662335D5B75] = 1; // USDC
              sgPoolIds[112][0x6626c47c00F1D87902fc13EECfaC3ed06D5E8D8a] = 20; // WOO
          }
          function _initTokenToOFTs(uint16 _sgChainIdLocal) internal {
              address btcbOFT = 0x2297aEbD383787A160DD0d9F71508148769342E3; // BTCbOFT && BTCbProxyOFT
              if (_sgChainIdLocal == 106) {
                  // BTC.b(ERC20) on Avalanche address
                  tokenToOFTs[0x152b9d0FdC40C096757F570A51E494bd4b943E50] = btcbOFT;
              }
              tokenToOFTs[btcbOFT] = btcbOFT;
          }
          function _getDstGasForCall(DstInfos memory dstInfos) internal view returns (uint256) {
              return (dstInfos.toToken == dstInfos.bridgeToken) ? dstGasForNoSwapCall : dstGasForSwapCall;
          }
          function _getAdapterParams(
              address to,
              address oft,
              uint256 dstGasForCall,
              DstInfos memory dstInfos
          ) internal view returns (bytes memory) {
              // OFT src logic: require(providedGasLimit >= minGasLimit)
              // uint256 minGasLimit = minDstGasLookup[_dstChainId][_type] + dstGasForCall;
              // _type: 0(send), 1(send_and_call)
              uint256 providedGasLimit = ILzApp(oft).minDstGasLookup(dstInfos.chainId, 1) + dstGasForCall;
              // https://layerzero.gitbook.io/docs/evm-guides/advanced/relayer-adapter-parameters#airdrop
              return
                  abi.encodePacked(
                      uint16(2), // version: 2 is able to airdrop native token on destination but 1 is not
                      providedGasLimit, // gasAmount: destination transaction gas for LayerZero to delivers
                      dstInfos.airdropNativeAmount, // nativeForDst: airdrop native token amount
                      to // addressOnDst: address to receive airdrop native token on destination
                  );
          }
          function _getLzTxObj(address to, DstInfos memory dstInfos) internal view returns (IStargateRouter.lzTxObj memory) {
              uint256 dstGasForCall = _getDstGasForCall(dstInfos);
              return IStargateRouter.lzTxObj(dstGasForCall, dstInfos.airdropNativeAmount, abi.encodePacked(to));
          }
          function _isLegitOFT(address caller) internal view returns (bool) {
              return tokenToOFTs[caller] != address(0);
          }
          function _bridgeByOFT(
              uint256 refId,
              address payable to,
              uint256 msgValue,
              uint256 bridgeAmount,
              IOFTWithFee oft,
              SrcInfos memory srcInfos,
              DstInfos memory dstInfos
          ) internal {
              {
                  address token = oft.token();
                  require(token == srcInfos.bridgeToken, "WooCrossChainRouterV2: !token");
                  if (token != address(oft)) {
                      // oft.token() != address(oft) means is a ProxyOFT
                      // for example: BTC.b on Avalanche is ERC20, need BTCbProxyOFT to lock up BTC.b
                      TransferHelper.safeApprove(srcInfos.bridgeToken, address(oft), bridgeAmount);
                  }
              }
              // OFT src logic: require(_removeDust(bridgeAmount) >= minAmount)
              uint256 minAmount = (bridgeAmount * (10000 - bridgeSlippage)) / 10000;
              bytes memory payload = abi.encode(refId, to, dstInfos.toToken, dstInfos.minToAmount);
              uint256 dstGasForCall = _getDstGasForCall(dstInfos);
              ICommonOFT.LzCallParams memory callParams;
              {
                  bytes memory adapterParams = _getAdapterParams(to, address(oft), dstGasForCall, dstInfos);
                  callParams = ICommonOFT.LzCallParams(
                      payable(msg.sender), // refundAddress
                      address(0), // zroPaymentAddress
                      adapterParams //adapterParams
                  );
              }
              bytes32 dstWooCrossChainRouter = bytes32(uint256(uint160(wooCrossChainRouters[dstInfos.chainId])));
              oft.sendAndCall{value: msgValue}(
                  address(this),
                  dstInfos.chainId,
                  dstWooCrossChainRouter,
                  bridgeAmount,
                  minAmount,
                  payload,
                  uint64(dstGasForCall),
                  callParams
              );
          }
          function _bridgeByStargate(
              uint256 refId,
              address payable to,
              uint256 msgValue,
              uint256 bridgeAmount,
              SrcInfos memory srcInfos,
              DstInfos memory dstInfos
          ) internal {
              uint256 srcPoolId = sgPoolIds[sgChainIdLocal][srcInfos.bridgeToken];
              require(srcPoolId > 0, "WooCrossChainRouterV2: !srcInfos.bridgeToken");
              uint256 dstPoolId = sgPoolIds[dstInfos.chainId][dstInfos.bridgeToken];
              require(dstPoolId > 0, "WooCrossChainRouterV2: !dstInfos.bridgeToken");
              bytes memory payload = abi.encode(refId, to, dstInfos.toToken, dstInfos.minToAmount);
              uint256 dstMinBridgeAmount = (bridgeAmount * (10000 - bridgeSlippage)) / 10000;
              bytes memory dstWooCrossChainRouter = abi.encodePacked(wooCrossChainRouters[dstInfos.chainId]);
              IStargateRouter.lzTxObj memory obj = _getLzTxObj(to, dstInfos);
              if (srcInfos.bridgeToken == weth) {
                  IWETH(weth).withdraw(bridgeAmount);
                  address sgETH = sgETHs[sgChainIdLocal];
                  IStargateEthVault(sgETH).deposit{value: bridgeAmount}(); // logic from Stargate RouterETH.sol
                  TransferHelper.safeApprove(sgETH, address(stargateRouter), bridgeAmount);
              } else {
                  TransferHelper.safeApprove(srcInfos.bridgeToken, address(stargateRouter), bridgeAmount);
              }
              stargateRouter.swap{value: msgValue}(
                  dstInfos.chainId, // dst chain id
                  srcPoolId, // bridge token's pool id on src chain
                  dstPoolId, // bridge token's pool id on dst chain
                  payable(_msgSender()), // rebate address
                  bridgeAmount, // swap amount on src chain
                  dstMinBridgeAmount, // min received amount on dst chain
                  obj, // config: dstGasForCall, dstAirdropNativeAmount, dstReceiveAirdropNativeTokenAddr
                  dstWooCrossChainRouter, // smart contract to call on dst chain
                  payload // payload to piggyback
              );
          }
          function _handleNativeReceived(
              uint256 refId,
              address to,
              address toToken,
              uint256 bridgedAmount,
              uint256 minToAmount
          ) internal {
              address msgSender = _msgSender();
              if (toToken == ETH_PLACEHOLDER_ADDR) {
                  TransferHelper.safeTransferETH(to, bridgedAmount);
                  emit WooCrossSwapOnDstChain(
                      refId,
                      msgSender,
                      to,
                      weth,
                      bridgedAmount,
                      toToken,
                      ETH_PLACEHOLDER_ADDR,
                      minToAmount,
                      bridgedAmount
                  );
              } else {
                  try
                      wooRouter.swap{value: bridgedAmount}(
                          ETH_PLACEHOLDER_ADDR,
                          toToken,
                          bridgedAmount,
                          minToAmount,
                          payable(to),
                          to
                      )
                  returns (uint256 realToAmount) {
                      emit WooCrossSwapOnDstChain(
                          refId,
                          msgSender,
                          to,
                          weth,
                          bridgedAmount,
                          toToken,
                          toToken,
                          minToAmount,
                          realToAmount
                      );
                  } catch {
                      TransferHelper.safeTransferETH(to, bridgedAmount);
                      emit WooCrossSwapOnDstChain(
                          refId,
                          msgSender,
                          to,
                          weth,
                          bridgedAmount,
                          toToken,
                          ETH_PLACEHOLDER_ADDR,
                          minToAmount,
                          bridgedAmount
                      );
                  }
              }
          }
          function _handleERC20Received(
              uint256 refId,
              address to,
              address toToken,
              address bridgedToken,
              uint256 bridgedAmount,
              uint256 minToAmount
          ) internal {
              address msgSender = _msgSender();
              if (toToken == bridgedToken) {
                  TransferHelper.safeTransfer(bridgedToken, to, bridgedAmount);
                  emit WooCrossSwapOnDstChain(
                      refId,
                      msgSender,
                      to,
                      bridgedToken,
                      bridgedAmount,
                      toToken,
                      toToken,
                      minToAmount,
                      bridgedAmount
                  );
              } else {
                  TransferHelper.safeApprove(bridgedToken, address(wooRouter), bridgedAmount);
                  try wooRouter.swap(bridgedToken, toToken, bridgedAmount, minToAmount, payable(to), to) returns (
                      uint256 realToAmount
                  ) {
                      emit WooCrossSwapOnDstChain(
                          refId,
                          msgSender,
                          to,
                          bridgedToken,
                          bridgedAmount,
                          toToken,
                          toToken,
                          minToAmount,
                          realToAmount
                      );
                  } catch {
                      TransferHelper.safeTransfer(bridgedToken, to, bridgedAmount);
                      emit WooCrossSwapOnDstChain(
                          refId,
                          msgSender,
                          to,
                          bridgedToken,
                          bridgedAmount,
                          toToken,
                          bridgedToken,
                          minToAmount,
                          bridgedAmount
                      );
                  }
              }
          }
          /* ----- Owner & Admin Functions ----- */
          function setWooRouter(address _wooRouter) external onlyOwner {
              require(_wooRouter != address(0), "WooCrossChainRouterV2: !_wooRouter");
              wooRouter = IWooRouterV2(_wooRouter);
          }
          function setStargateRouter(address _stargateRouter) external onlyOwner {
              require(_stargateRouter != address(0), "WooCrossChainRouterV2: !_stargateRouter");
              stargateRouter = IStargateRouter(_stargateRouter);
          }
          function setBridgeSlippage(uint256 _bridgeSlippage) external onlyOwner {
              require(_bridgeSlippage <= 10000, "WooCrossChainRouterV2: !_bridgeSlippage");
              bridgeSlippage = _bridgeSlippage;
          }
          function setDstGasForSwapCall(uint256 _dstGasForSwapCall) external onlyOwner {
              dstGasForSwapCall = _dstGasForSwapCall;
          }
          function setDstGasForNoSwapCall(uint256 _dstGasForNoSwapCall) external onlyOwner {
              dstGasForNoSwapCall = _dstGasForNoSwapCall;
          }
          function setSgChainIdLocal(uint16 _sgChainIdLocal) external onlyOwner {
              sgChainIdLocal = _sgChainIdLocal;
          }
          function setWooCrossChainRouter(uint16 chainId, address wooCrossChainRouter) external onlyOwner {
              require(wooCrossChainRouter != address(0), "WooCrossChainRouterV2: !wooCrossChainRouter");
              wooCrossChainRouters[chainId] = wooCrossChainRouter;
          }
          function setSgETH(uint16 chainId, address token) external onlyOwner {
              require(token != address(0), "WooCrossChainRouterV2: !token");
              sgETHs[chainId] = token;
          }
          function setSgPoolId(
              uint16 chainId,
              address token,
              uint256 poolId
          ) external onlyOwner {
              sgPoolIds[chainId][token] = poolId;
          }
          function setTokenToOFT(address token, address oft) external onlyOwner {
              tokenToOFTs[token] = oft;
          }
          function addDirectBridgeToken(address token) external onlyOwner {
              bool success = directBridgeTokens.add(token);
              require(success, "WooCrossChainRouterV2: token exist");
          }
          function removeDirectBridgeToken(address token) external onlyOwner {
              bool success = directBridgeTokens.remove(token);
              require(success, "WooCrossChainRouterV2: token not exist");
          }
          function inCaseTokenGotStuck(address stuckToken) external onlyOwner {
              if (stuckToken == ETH_PLACEHOLDER_ADDR) {
                  TransferHelper.safeTransferETH(msg.sender, address(this).balance);
              } else {
                  uint256 amount = IERC20(stuckToken).balanceOf(address(this));
                  TransferHelper.safeTransfer(stuckToken, msg.sender, amount);
              }
          }
      }
      // SPDX-License-Identifier: MIT
      pragma solidity ^0.8.0;
      /// @title Wrapped ETH.
      interface IWETH {
          /// @dev Deposit ETH into WETH
          function deposit() external payable;
          /// @dev Transfer WETH to receiver
          /// @param to address of WETH receiver
          /// @param value amount of WETH to transfer
          /// @return get true when succeed, else false
          function transfer(address to, uint256 value) external returns (bool);
          /// @dev Withdraw WETH to ETH
          function withdraw(uint256) external;
      }
      // SPDX-License-Identifier: MIT
      pragma solidity =0.8.14;
      /*
      ░██╗░░░░░░░██╗░█████╗░░█████╗░░░░░░░███████╗██╗
      ░██║░░██╗░░██║██╔══██╗██╔══██╗░░░░░░██╔════╝██║
      ░╚██╗████╗██╔╝██║░░██║██║░░██║█████╗█████╗░░██║
      ░░████╔═████║░██║░░██║██║░░██║╚════╝██╔══╝░░██║
      ░░╚██╔╝░╚██╔╝░╚█████╔╝╚█████╔╝░░░░░░██║░░░░░██║
      ░░░╚═╝░░░╚═╝░░░╚════╝░░╚════╝░░░░░░░╚═╝░░░░░╚═╝
      *
      * MIT License
      * ===========
      *
      * Copyright (c) 2020 WooTrade
      *
      * Permission is hereby granted, free of charge, to any person obtaining a copy
      * of this software and associated documentation files (the "Software"), to deal
      * in the Software without restriction, including without limitation the rights
      * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
      * copies of the Software, and to permit persons to whom the Software is
      * furnished to do so, subject to the following conditions:
      *
      * The above copyright notice and this permission notice shall be included in all
      * copies or substantial portions of the Software.
      *
      * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
      * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
      * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
      * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
      * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
      * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
      */
      /// @title WOOFi cross chain router interface (version 2).
      /// @notice functions to interface with WOOFi cross chain swap.
      interface IWooCrossChainRouterV2 {
          /* ----- Structs ----- */
          struct SrcInfos {
              address fromToken;
              address bridgeToken;
              uint256 fromAmount;
              uint256 minBridgeAmount;
          }
          struct DstInfos {
              uint16 chainId;
              address toToken;
              address bridgeToken;
              uint256 minToAmount;
              uint256 airdropNativeAmount;
          }
          /* ----- Events ----- */
          event WooCrossSwapOnSrcChain(
              uint256 indexed refId,
              address indexed sender,
              address indexed to,
              address fromToken,
              uint256 fromAmount,
              uint256 minBridgeAmount,
              uint256 realBridgeAmount
          );
          event WooCrossSwapOnDstChain(
              uint256 indexed refId,
              address indexed sender,
              address indexed to,
              address bridgedToken,
              uint256 bridgedAmount,
              address toToken,
              address realToToken,
              uint256 minToAmount,
              uint256 realToAmount
          );
          /* ----- State Variables ----- */
          function weth() external view returns (address);
          function bridgeSlippage() external view returns (uint256);
          function dstGasForSwapCall() external view returns (uint256);
          function dstGasForNoSwapCall() external view returns (uint256);
          function sgChainIdLocal() external view returns (uint16);
          function wooCrossChainRouters(uint16 chainId) external view returns (address wooCrossChainRouter);
          function sgETHs(uint16 chainId) external view returns (address sgETH);
          function sgPoolIds(uint16 chainId, address token) external view returns (uint256 poolId);
          /* ----- Functions ----- */
          function crossSwap(
              uint256 refId,
              address payable to,
              SrcInfos memory srcInfos,
              DstInfos memory dstInfos
          ) external payable;
          function sgReceive(
              uint16 srcChainId,
              bytes memory srcAddress,
              uint256 nonce,
              address bridgedToken,
              uint256 amountLD,
              bytes memory payload
          ) external;
          function quoteLayerZeroFee(
              uint256 refId,
              address to,
              SrcInfos memory srcInfos,
              DstInfos memory dstInfos
          ) external view returns (uint256 nativeAmount, uint256 zroAmount);
          function allDirectBridgeTokens() external view returns (address[] memory tokens);
          function allDirectBridgeTokensLength() external view returns (uint256 length);
      }
      // SPDX-License-Identifier: MIT
      pragma solidity =0.8.14;
      /*
      ░██╗░░░░░░░██╗░█████╗░░█████╗░░░░░░░███████╗██╗
      ░██║░░██╗░░██║██╔══██╗██╔══██╗░░░░░░██╔════╝██║
      ░╚██╗████╗██╔╝██║░░██║██║░░██║█████╗█████╗░░██║
      ░░████╔═████║░██║░░██║██║░░██║╚════╝██╔══╝░░██║
      ░░╚██╔╝░╚██╔╝░╚█████╔╝╚█████╔╝░░░░░░██║░░░░░██║
      ░░░╚═╝░░░╚═╝░░░╚════╝░░╚════╝░░░░░░░╚═╝░░░░░╚═╝
      *
      * MIT License
      * ===========
      *
      * Copyright (c) 2020 WooTrade
      *
      * Permission is hereby granted, free of charge, to any person obtaining a copy
      * of this software and associated documentation files (the "Software"), to deal
      * in the Software without restriction, including without limitation the rights
      * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
      * copies of the Software, and to permit persons to whom the Software is
      * furnished to do so, subject to the following conditions:
      *
      * The above copyright notice and this permission notice shall be included in all
      * copies or substantial portions of the Software.
      *
      * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
      * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
      * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
      * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
      * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
      * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
      */
      import "../interfaces/IWooPPV2.sol";
      /// @title Woo router interface (version 2)
      /// @notice functions to interface with WooFi swap
      interface IWooRouterV2 {
          /* ----- Type declarations ----- */
          enum SwapType {
              WooSwap,
              DodoSwap
          }
          /* ----- Events ----- */
          event WooRouterSwap(
              SwapType swapType,
              address indexed fromToken,
              address indexed toToken,
              uint256 fromAmount,
              uint256 toAmount,
              address from,
              address indexed to,
              address rebateTo
          );
          event WooPoolChanged(address newPool);
          /* ----- Router properties ----- */
          function WETH() external view returns (address);
          function wooPool() external view returns (IWooPPV2);
          /* ----- Main query & swap APIs ----- */
          /// @notice query the amount to swap fromToken -> toToken
          /// @param fromToken the from token
          /// @param toToken the to token
          /// @param fromAmount the amount of fromToken to swap
          /// @return toAmount the predicted amount to receive
          function querySwap(
              address fromToken,
              address toToken,
              uint256 fromAmount
          ) external view returns (uint256 toAmount);
          /// @notice query the amount to swap fromToken -> toToken,
          ///     WITHOUT checking the reserve balance; so it
          ///     always returns the quoted amount (for reference).
          /// @param fromToken the from token
          /// @param toToken the to token
          /// @param fromAmount the amount of fromToken to swap
          /// @return toAmount the predicted amount to receive
          function tryQuerySwap(
              address fromToken,
              address toToken,
              uint256 fromAmount
          ) external view returns (uint256 toAmount);
          /// @notice Swap `fromToken` to `toToken`.
          /// @param fromToken the from token
          /// @param toToken the to token
          /// @param fromAmount the amount of `fromToken` to swap
          /// @param minToAmount the minimum amount of `toToken` to receive
          /// @param to the destination address
          /// @param rebateTo the rebate address (optional, can be 0)
          /// @return realToAmount the amount of toToken to receive
          function swap(
              address fromToken,
              address toToken,
              uint256 fromAmount,
              uint256 minToAmount,
              address payable to,
              address rebateTo
          ) external payable returns (uint256 realToAmount);
          /* ----- 3rd party DEX swap ----- */
          /// @notice swap fromToken -> toToken via an external 3rd swap
          /// @param approveTarget the contract address for token transfer approval
          /// @param swapTarget the contract address for swap
          /// @param fromToken the from token
          /// @param toToken the to token
          /// @param fromAmount the amount of fromToken to swap
          /// @param minToAmount the min amount of swapped toToken
          /// @param to the destination address
          /// @param data call data for external call
          function externalSwap(
              address approveTarget,
              address swapTarget,
              address fromToken,
              address toToken,
              uint256 fromAmount,
              uint256 minToAmount,
              address payable to,
              bytes calldata data
          ) external payable returns (uint256 realToAmount);
      }
      // SPDX-License-Identifier: GPL-3.0-or-later
      pragma solidity ^0.8.0;
      // 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,
              uint256 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::safeApprove: approve failed"
              );
          }
          function safeTransfer(
              address token,
              address to,
              uint256 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::safeTransfer: transfer failed"
              );
          }
          function safeTransferFrom(
              address token,
              address from,
              address to,
              uint256 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::transferFrom: transferFrom failed"
              );
          }
          function safeTransferETH(address to, uint256 value) internal {
              (bool success, ) = to.call{value: value}(new bytes(0));
              require(success, "TransferHelper::safeTransferETH: ETH transfer failed");
          }
      }
      // SPDX-License-Identifier: MIT
      pragma solidity ^0.8.0;
      interface IStargateEthVault {
          function deposit() external payable;
          function transfer(address to, uint256 value) external returns (bool);
          function withdraw(uint256) external;
          function approve(address guy, uint256 wad) external returns (bool);
          function transferFrom(
              address src,
              address dst,
              uint256 wad
          ) external returns (bool);
      }
      // SPDX-License-Identifier: MIT
      pragma solidity ^0.8.0;
      interface IStargateRouter {
          struct lzTxObj {
              uint256 dstGasForCall;
              uint256 dstNativeAmount;
              bytes dstNativeAddr;
          }
          function addLiquidity(
              uint256 _poolId,
              uint256 _amountLD,
              address _to
          ) external;
          function swap(
              uint16 _dstChainId,
              uint256 _srcPoolId,
              uint256 _dstPoolId,
              address payable _refundAddress,
              uint256 _amountLD,
              uint256 _minAmountLD,
              lzTxObj memory _lzTxParams,
              bytes calldata _to,
              bytes calldata _payload
          ) external payable;
          function redeemRemote(
              uint16 _dstChainId,
              uint256 _srcPoolId,
              uint256 _dstPoolId,
              address payable _refundAddress,
              uint256 _amountLP,
              uint256 _minAmountLD,
              bytes calldata _to,
              lzTxObj memory _lzTxParams
          ) external payable;
          function instantRedeemLocal(
              uint16 _srcPoolId,
              uint256 _amountLP,
              address _to
          ) external returns (uint256);
          function redeemLocal(
              uint16 _dstChainId,
              uint256 _srcPoolId,
              uint256 _dstPoolId,
              address payable _refundAddress,
              uint256 _amountLP,
              bytes calldata _to,
              lzTxObj memory _lzTxParams
          ) external payable;
          function sendCredits(
              uint16 _dstChainId,
              uint256 _srcPoolId,
              uint256 _dstPoolId,
              address payable _refundAddress
          ) external payable;
          function quoteLayerZeroFee(
              uint16 _dstChainId,
              uint8 _functionType,
              bytes calldata _toAddress,
              bytes calldata _transferAndCallPayload,
              lzTxObj memory _lzTxParams
          ) external view returns (uint256, uint256);
      }
      // SPDX-License-Identifier: MIT
      pragma solidity ^0.8.0;
      /**
       * @dev Interface of the LzApp that functions not exist in the @layerzerolabs package
       */
      interface ILzApp {
          function minDstGasLookup(uint16 _dstChainId, uint16 _type) external view returns (uint256 _minGasLimit);
      }
      // SPDX-License-Identifier: MIT
      // OpenZeppelin Contracts (last updated v4.7.0) (access/Ownable.sol)
      pragma solidity ^0.8.0;
      import "../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.
       *
       * By default, the owner account will be the one that deploys the contract. 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;
          event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
          /**
           * @dev Initializes the contract setting the deployer as the initial owner.
           */
          constructor() {
              _transferOwnership(_msgSender());
          }
          /**
           * @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 {
              require(owner() == _msgSender(), "Ownable: caller is not the owner");
          }
          /**
           * @dev Leaves the contract without owner. It will not be possible to call
           * `onlyOwner` functions anymore. Can only be called by the current owner.
           *
           * NOTE: Renouncing ownership will leave the contract without an owner,
           * thereby removing 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 {
              require(newOwner != address(0), "Ownable: new owner is the zero address");
              _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 v4.4.1 (security/ReentrancyGuard.sol)
      pragma solidity ^0.8.0;
      /**
       * @dev Contract module that helps prevent reentrant calls to a function.
       *
       * Inheriting from `ReentrancyGuard` will make the {nonReentrant} modifier
       * available, which can be applied to functions to make sure there are no nested
       * (reentrant) calls to them.
       *
       * Note that because there is a single `nonReentrant` guard, functions marked as
       * `nonReentrant` may not call one another. This can be worked around by making
       * those functions `private`, and then adding `external` `nonReentrant` entry
       * points to them.
       *
       * TIP: If you would like to learn more about reentrancy and alternative ways
       * to protect against it, check out our blog post
       * https://blog.openzeppelin.com/reentrancy-after-istanbul/[Reentrancy After Istanbul].
       */
      abstract contract ReentrancyGuard {
          // Booleans are more expensive than uint256 or any type that takes up a full
          // word because each write operation emits an extra SLOAD to first read the
          // slot's contents, replace the bits taken up by the boolean, and then write
          // back. This is the compiler's defense against contract upgrades and
          // pointer aliasing, and it cannot be disabled.
          // The values being non-zero value makes deployment a bit more expensive,
          // but in exchange the refund on every call to nonReentrant will be lower in
          // amount. Since refunds are capped to a percentage of the total
          // transaction's gas, it is best to keep them low in cases like this one, to
          // increase the likelihood of the full refund coming into effect.
          uint256 private constant _NOT_ENTERED = 1;
          uint256 private constant _ENTERED = 2;
          uint256 private _status;
          constructor() {
              _status = _NOT_ENTERED;
          }
          /**
           * @dev Prevents a contract from calling itself, directly or indirectly.
           * Calling a `nonReentrant` function from another `nonReentrant`
           * function is not supported. It is possible to prevent this from happening
           * by making the `nonReentrant` function external, and making it call a
           * `private` function that does the actual work.
           */
          modifier nonReentrant() {
              // On the first call to nonReentrant, _notEntered will be true
              require(_status != _ENTERED, "ReentrancyGuard: reentrant call");
              // Any calls to nonReentrant after this point will fail
              _status = _ENTERED;
              _;
              // By storing the original value once again, a refund is triggered (see
              // https://eips.ethereum.org/EIPS/eip-2200)
              _status = _NOT_ENTERED;
          }
      }
      // SPDX-License-Identifier: MIT
      // OpenZeppelin Contracts (last updated v4.6.0) (token/ERC20/IERC20.sol)
      pragma solidity ^0.8.0;
      /**
       * @dev Interface of the ERC20 standard as defined in the EIP.
       */
      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 amount of tokens in existence.
           */
          function totalSupply() external view returns (uint256);
          /**
           * @dev Returns the amount of tokens owned by `account`.
           */
          function balanceOf(address account) external view returns (uint256);
          /**
           * @dev Moves `amount` 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 amount) 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 `amount` 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 amount) external returns (bool);
          /**
           * @dev Moves `amount` tokens from `from` to `to` using the
           * allowance mechanism. `amount` 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 amount
          ) external returns (bool);
      }
      // SPDX-License-Identifier: MIT
      // OpenZeppelin Contracts (last updated v4.7.0) (utils/structs/EnumerableSet.sol)
      pragma solidity ^0.8.0;
      /**
       * @dev Library for managing
       * https://en.wikipedia.org/wiki/Set_(abstract_data_type)[sets] of primitive
       * types.
       *
       * Sets have the following properties:
       *
       * - Elements are added, removed, and checked for existence in constant time
       * (O(1)).
       * - Elements are enumerated in O(n). No guarantees are made on the ordering.
       *
       * ```
       * contract Example {
       *     // Add the library methods
       *     using EnumerableSet for EnumerableSet.AddressSet;
       *
       *     // Declare a set state variable
       *     EnumerableSet.AddressSet private mySet;
       * }
       * ```
       *
       * As of v3.3.0, sets of type `bytes32` (`Bytes32Set`), `address` (`AddressSet`)
       * and `uint256` (`UintSet`) are supported.
       *
       * [WARNING]
       * ====
       *  Trying to delete such a structure from storage will likely result in data corruption, rendering the structure unusable.
       *  See https://github.com/ethereum/solidity/pull/11843[ethereum/solidity#11843] for more info.
       *
       *  In order to clean an EnumerableSet, you can either remove all elements one by one or create a fresh instance using an array of EnumerableSet.
       * ====
       */
      library EnumerableSet {
          // To implement this library for multiple types with as little code
          // repetition as possible, we write it in terms of a generic Set type with
          // bytes32 values.
          // The Set implementation uses private functions, and user-facing
          // implementations (such as AddressSet) are just wrappers around the
          // underlying Set.
          // This means that we can only create new EnumerableSets for types that fit
          // in bytes32.
          struct Set {
              // Storage of set values
              bytes32[] _values;
              // Position of the value in the `values` array, plus 1 because index 0
              // means a value is not in the set.
              mapping(bytes32 => uint256) _indexes;
          }
          /**
           * @dev Add a value to a set. O(1).
           *
           * Returns true if the value was added to the set, that is if it was not
           * already present.
           */
          function _add(Set storage set, bytes32 value) private returns (bool) {
              if (!_contains(set, value)) {
                  set._values.push(value);
                  // The value is stored at length-1, but we add 1 to all indexes
                  // and use 0 as a sentinel value
                  set._indexes[value] = set._values.length;
                  return true;
              } else {
                  return false;
              }
          }
          /**
           * @dev Removes a value from a set. O(1).
           *
           * Returns true if the value was removed from the set, that is if it was
           * present.
           */
          function _remove(Set storage set, bytes32 value) private returns (bool) {
              // We read and store the value's index to prevent multiple reads from the same storage slot
              uint256 valueIndex = set._indexes[value];
              if (valueIndex != 0) {
                  // Equivalent to contains(set, value)
                  // To delete an element from the _values array in O(1), we swap the element to delete with the last one in
                  // the array, and then remove the last element (sometimes called as 'swap and pop').
                  // This modifies the order of the array, as noted in {at}.
                  uint256 toDeleteIndex = valueIndex - 1;
                  uint256 lastIndex = set._values.length - 1;
                  if (lastIndex != toDeleteIndex) {
                      bytes32 lastValue = set._values[lastIndex];
                      // Move the last value to the index where the value to delete is
                      set._values[toDeleteIndex] = lastValue;
                      // Update the index for the moved value
                      set._indexes[lastValue] = valueIndex; // Replace lastValue's index to valueIndex
                  }
                  // Delete the slot where the moved value was stored
                  set._values.pop();
                  // Delete the index for the deleted slot
                  delete set._indexes[value];
                  return true;
              } else {
                  return false;
              }
          }
          /**
           * @dev Returns true if the value is in the set. O(1).
           */
          function _contains(Set storage set, bytes32 value) private view returns (bool) {
              return set._indexes[value] != 0;
          }
          /**
           * @dev Returns the number of values on the set. O(1).
           */
          function _length(Set storage set) private view returns (uint256) {
              return set._values.length;
          }
          /**
           * @dev Returns the value stored at position `index` in the set. O(1).
           *
           * Note that there are no guarantees on the ordering of values inside the
           * array, and it may change when more values are added or removed.
           *
           * Requirements:
           *
           * - `index` must be strictly less than {length}.
           */
          function _at(Set storage set, uint256 index) private view returns (bytes32) {
              return set._values[index];
          }
          /**
           * @dev Return the entire set in an array
           *
           * WARNING: This operation will copy the entire storage to memory, which can be quite expensive. This is designed
           * to mostly be used by view accessors that are queried without any gas fees. Developers should keep in mind that
           * this function has an unbounded cost, and using it as part of a state-changing function may render the function
           * uncallable if the set grows to a point where copying to memory consumes too much gas to fit in a block.
           */
          function _values(Set storage set) private view returns (bytes32[] memory) {
              return set._values;
          }
          // Bytes32Set
          struct Bytes32Set {
              Set _inner;
          }
          /**
           * @dev Add a value to a set. O(1).
           *
           * Returns true if the value was added to the set, that is if it was not
           * already present.
           */
          function add(Bytes32Set storage set, bytes32 value) internal returns (bool) {
              return _add(set._inner, value);
          }
          /**
           * @dev Removes a value from a set. O(1).
           *
           * Returns true if the value was removed from the set, that is if it was
           * present.
           */
          function remove(Bytes32Set storage set, bytes32 value) internal returns (bool) {
              return _remove(set._inner, value);
          }
          /**
           * @dev Returns true if the value is in the set. O(1).
           */
          function contains(Bytes32Set storage set, bytes32 value) internal view returns (bool) {
              return _contains(set._inner, value);
          }
          /**
           * @dev Returns the number of values in the set. O(1).
           */
          function length(Bytes32Set storage set) internal view returns (uint256) {
              return _length(set._inner);
          }
          /**
           * @dev Returns the value stored at position `index` in the set. O(1).
           *
           * Note that there are no guarantees on the ordering of values inside the
           * array, and it may change when more values are added or removed.
           *
           * Requirements:
           *
           * - `index` must be strictly less than {length}.
           */
          function at(Bytes32Set storage set, uint256 index) internal view returns (bytes32) {
              return _at(set._inner, index);
          }
          /**
           * @dev Return the entire set in an array
           *
           * WARNING: This operation will copy the entire storage to memory, which can be quite expensive. This is designed
           * to mostly be used by view accessors that are queried without any gas fees. Developers should keep in mind that
           * this function has an unbounded cost, and using it as part of a state-changing function may render the function
           * uncallable if the set grows to a point where copying to memory consumes too much gas to fit in a block.
           */
          function values(Bytes32Set storage set) internal view returns (bytes32[] memory) {
              return _values(set._inner);
          }
          // AddressSet
          struct AddressSet {
              Set _inner;
          }
          /**
           * @dev Add a value to a set. O(1).
           *
           * Returns true if the value was added to the set, that is if it was not
           * already present.
           */
          function add(AddressSet storage set, address value) internal returns (bool) {
              return _add(set._inner, bytes32(uint256(uint160(value))));
          }
          /**
           * @dev Removes a value from a set. O(1).
           *
           * Returns true if the value was removed from the set, that is if it was
           * present.
           */
          function remove(AddressSet storage set, address value) internal returns (bool) {
              return _remove(set._inner, bytes32(uint256(uint160(value))));
          }
          /**
           * @dev Returns true if the value is in the set. O(1).
           */
          function contains(AddressSet storage set, address value) internal view returns (bool) {
              return _contains(set._inner, bytes32(uint256(uint160(value))));
          }
          /**
           * @dev Returns the number of values in the set. O(1).
           */
          function length(AddressSet storage set) internal view returns (uint256) {
              return _length(set._inner);
          }
          /**
           * @dev Returns the value stored at position `index` in the set. O(1).
           *
           * Note that there are no guarantees on the ordering of values inside the
           * array, and it may change when more values are added or removed.
           *
           * Requirements:
           *
           * - `index` must be strictly less than {length}.
           */
          function at(AddressSet storage set, uint256 index) internal view returns (address) {
              return address(uint160(uint256(_at(set._inner, index))));
          }
          /**
           * @dev Return the entire set in an array
           *
           * WARNING: This operation will copy the entire storage to memory, which can be quite expensive. This is designed
           * to mostly be used by view accessors that are queried without any gas fees. Developers should keep in mind that
           * this function has an unbounded cost, and using it as part of a state-changing function may render the function
           * uncallable if the set grows to a point where copying to memory consumes too much gas to fit in a block.
           */
          function values(AddressSet storage set) internal view returns (address[] memory) {
              bytes32[] memory store = _values(set._inner);
              address[] memory result;
              /// @solidity memory-safe-assembly
              assembly {
                  result := store
              }
              return result;
          }
          // UintSet
          struct UintSet {
              Set _inner;
          }
          /**
           * @dev Add a value to a set. O(1).
           *
           * Returns true if the value was added to the set, that is if it was not
           * already present.
           */
          function add(UintSet storage set, uint256 value) internal returns (bool) {
              return _add(set._inner, bytes32(value));
          }
          /**
           * @dev Removes a value from a set. O(1).
           *
           * Returns true if the value was removed from the set, that is if it was
           * present.
           */
          function remove(UintSet storage set, uint256 value) internal returns (bool) {
              return _remove(set._inner, bytes32(value));
          }
          /**
           * @dev Returns true if the value is in the set. O(1).
           */
          function contains(UintSet storage set, uint256 value) internal view returns (bool) {
              return _contains(set._inner, bytes32(value));
          }
          /**
           * @dev Returns the number of values on the set. O(1).
           */
          function length(UintSet storage set) internal view returns (uint256) {
              return _length(set._inner);
          }
          /**
           * @dev Returns the value stored at position `index` in the set. O(1).
           *
           * Note that there are no guarantees on the ordering of values inside the
           * array, and it may change when more values are added or removed.
           *
           * Requirements:
           *
           * - `index` must be strictly less than {length}.
           */
          function at(UintSet storage set, uint256 index) internal view returns (uint256) {
              return uint256(_at(set._inner, index));
          }
          /**
           * @dev Return the entire set in an array
           *
           * WARNING: This operation will copy the entire storage to memory, which can be quite expensive. This is designed
           * to mostly be used by view accessors that are queried without any gas fees. Developers should keep in mind that
           * this function has an unbounded cost, and using it as part of a state-changing function may render the function
           * uncallable if the set grows to a point where copying to memory consumes too much gas to fit in a block.
           */
          function values(UintSet storage set) internal view returns (uint256[] memory) {
              bytes32[] memory store = _values(set._inner);
              uint256[] memory result;
              /// @solidity memory-safe-assembly
              assembly {
                  result := store
              }
              return result;
          }
      }
      // SPDX-License-Identifier: MIT
      pragma solidity >=0.5.0;
      import "../ICommonOFT.sol";
      /**
       * @dev Interface of the IOFT core standard
       */
      interface IOFTWithFee is ICommonOFT {
          /**
           * @dev send `_amount` amount of token to (`_dstChainId`, `_toAddress`) from `_from`
           * `_from` the owner of token
           * `_dstChainId` the destination chain identifier
           * `_toAddress` can be any size depending on the `dstChainId`.
           * `_amount` the quantity of tokens in wei
           * `_minAmount` the minimum amount of tokens to receive on dstChain
           * `_refundAddress` the address LayerZero refunds if too much message fee is sent
           * `_zroPaymentAddress` set to address(0x0) if not paying in ZRO (LayerZero Token)
           * `_adapterParams` is a flexible bytes array to indicate messaging adapter services
           */
          function sendFrom(address _from, uint16 _dstChainId, bytes32 _toAddress, uint _amount, uint _minAmount, LzCallParams calldata _callParams) external payable;
          function sendAndCall(address _from, uint16 _dstChainId, bytes32 _toAddress, uint _amount, uint _minAmount, bytes calldata _payload, uint64 _dstGasForCall, LzCallParams calldata _callParams) external payable;
      }
      // SPDX-License-Identifier: MIT
      pragma solidity =0.8.14;
      /*
      ░██╗░░░░░░░██╗░█████╗░░█████╗░░░░░░░███████╗██╗
      ░██║░░██╗░░██║██╔══██╗██╔══██╗░░░░░░██╔════╝██║
      ░╚██╗████╗██╔╝██║░░██║██║░░██║█████╗█████╗░░██║
      ░░████╔═████║░██║░░██║██║░░██║╚════╝██╔══╝░░██║
      ░░╚██╔╝░╚██╔╝░╚█████╔╝╚█████╔╝░░░░░░██║░░░░░██║
      ░░░╚═╝░░░╚═╝░░░╚════╝░░╚════╝░░░░░░░╚═╝░░░░░╚═╝
      *
      * MIT License
      * ===========
      *
      * Copyright (c) 2020 WooTrade
      *
      * Permission is hereby granted, free of charge, to any person obtaining a copy
      * of this software and associated documentation files (the "Software"), to deal
      * in the Software without restriction, including without limitation the rights
      * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
      * copies of the Software, and to permit persons to whom the Software is
      * furnished to do so, subject to the following conditions:
      *
      * The above copyright notice and this permission notice shall be included in all
      * copies or substantial portions of the Software.
      *
      * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
      * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
      * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
      * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
      * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
      * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
      */
      /// @title Woo private pool for swap.
      /// @notice Use this contract to directly interfact with woo's synthetic proactive
      ///         marketing making pool.
      /// @author woo.network
      interface IWooPPV2 {
          /* ----- Events ----- */
          event Deposit(address indexed token, address indexed sender, uint256 amount);
          event Withdraw(address indexed token, address indexed receiver, uint256 amount);
          event Migrate(address indexed token, address indexed receiver, uint256 amount);
          event AdminUpdated(address indexed addr, bool flag);
          event FeeAddrUpdated(address indexed newFeeAddr);
          event WooracleUpdated(address indexed newWooracle);
          event WooSwap(
              address indexed fromToken,
              address indexed toToken,
              uint256 fromAmount,
              uint256 toAmount,
              address from,
              address indexed to,
              address rebateTo,
              uint256 swapVol,
              uint256 swapFee
          );
          /* ----- External Functions ----- */
          /// @notice The quote token address (immutable).
          /// @return address of quote token
          function quoteToken() external view returns (address);
          /// @notice Gets the pool size of the specified token (swap liquidity).
          /// @param token the token address
          /// @return the pool size
          function poolSize(address token) external view returns (uint256);
          /// @notice Query the amount to swap `fromToken` to `toToken`, without checking the pool reserve balance.
          /// @param fromToken the from token
          /// @param toToken the to token
          /// @param fromAmount the amount of `fromToken` to swap
          /// @return toAmount the swapped amount of `toToken`
          function tryQuery(
              address fromToken,
              address toToken,
              uint256 fromAmount
          ) external view returns (uint256 toAmount);
          /// @notice Query the amount to swap `fromToken` to `toToken`, with checking the pool reserve balance.
          /// @dev tx reverts when 'toToken' balance is insufficient.
          /// @param fromToken the from token
          /// @param toToken the to token
          /// @param fromAmount the amount of `fromToken` to swap
          /// @return toAmount the swapped amount of `toToken`
          function query(
              address fromToken,
              address toToken,
              uint256 fromAmount
          ) external view returns (uint256 toAmount);
          /// @notice Swap `fromToken` to `toToken`.
          /// @param fromToken the from token
          /// @param toToken the to token
          /// @param fromAmount the amount of `fromToken` to swap
          /// @param minToAmount the minimum amount of `toToken` to receive
          /// @param to the destination address
          /// @param rebateTo the rebate address (optional, can be address ZERO)
          /// @return realToAmount the amount of toToken to receive
          function swap(
              address fromToken,
              address toToken,
              uint256 fromAmount,
              uint256 minToAmount,
              address to,
              address rebateTo
          ) external returns (uint256 realToAmount);
          /// @notice Deposit the specified token into the liquidity pool of WooPPV2.
          /// @param token the token to deposit
          /// @param amount the deposit amount
          function deposit(address token, uint256 amount) external;
      }
      // SPDX-License-Identifier: MIT
      // OpenZeppelin Contracts v4.4.1 (utils/Context.sol)
      pragma solidity ^0.8.0;
      /**
       * @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;
          }
      }
      // SPDX-License-Identifier: MIT
      pragma solidity >=0.5.0;
      import "@openzeppelin/contracts/utils/introspection/IERC165.sol";
      /**
       * @dev Interface of the IOFT core standard
       */
      interface ICommonOFT is IERC165 {
          struct LzCallParams {
              address payable refundAddress;
              address zroPaymentAddress;
              bytes adapterParams;
          }
          /**
           * @dev estimate send token `_tokenId` to (`_dstChainId`, `_toAddress`)
           * _dstChainId - L0 defined chain id to send tokens too
           * _toAddress - dynamic bytes array which contains the address to whom you are sending tokens to on the dstChain
           * _amount - amount of the tokens to transfer
           * _useZro - indicates to use zro to pay L0 fees
           * _adapterParam - flexible bytes array to indicate messaging adapter services in L0
           */
          function estimateSendFee(uint16 _dstChainId, bytes32 _toAddress, uint _amount, bool _useZro, bytes calldata _adapterParams) external view returns (uint nativeFee, uint zroFee);
          function estimateSendAndCallFee(uint16 _dstChainId, bytes32 _toAddress, uint _amount, bytes calldata _payload, uint64 _dstGasForCall, bool _useZro, bytes calldata _adapterParams) external view returns (uint nativeFee, uint zroFee);
          /**
           * @dev returns the circulating amount of tokens on current chain
           */
          function circulatingSupply() external view returns (uint);
          /**
           * @dev returns the address of the ERC20 token
           */
          function token() external view returns (address);
      }
      // SPDX-License-Identifier: MIT
      // OpenZeppelin Contracts v4.4.1 (utils/introspection/IERC165.sol)
      pragma solidity ^0.8.0;
      /**
       * @dev Interface of the ERC165 standard, as defined in the
       * https://eips.ethereum.org/EIPS/eip-165[EIP].
       *
       * 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[EIP 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);
      }
      

      File 2 of 4: WETH9
      // 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.
      
                                  Preamble
      
        The GNU General Public License is a free, copyleft license for
      software and other kinds of works.
      
        The licenses for most software and other practical works are designed
      to take away your freedom to share and change the works.  By contrast,
      the GNU General Public License is intended to guarantee your freedom to
      share and change all versions of a program--to make sure it remains free
      software for all its users.  We, the Free Software Foundation, use the
      GNU General Public License for most of our software; it applies also to
      any other work released this way by its authors.  You can apply it to
      your programs, too.
      
        When we speak of free software, we are referring to freedom, not
      price.  Our General Public Licenses are designed to make sure that you
      have the freedom to distribute copies of free software (and charge for
      them if you wish), that you receive source code or can get it if you
      want it, that you can change the software or use pieces of it in new
      free programs, and that you know you can do these things.
      
        To protect your rights, we need to prevent others from denying you
      these rights or asking you to surrender the rights.  Therefore, you have
      certain responsibilities if you distribute copies of the software, or if
      you modify it: responsibilities to respect the freedom of others.
      
        For example, if you distribute copies of such a program, whether
      gratis or for a fee, you must pass on to the recipients the same
      freedoms that you received.  You must make sure that they, too, receive
      or can get the source code.  And you must show them these terms so they
      know their rights.
      
        Developers that use the GNU GPL protect your rights with two steps:
      (1) assert copyright on the software, and (2) offer you this License
      giving you legal permission to copy, distribute and/or modify it.
      
        For the developers' and authors' protection, the GPL clearly explains
      that there is no warranty for this free software.  For both users' and
      authors' sake, the GPL requires that modified versions be marked as
      changed, so that their problems will not be attributed erroneously to
      authors of previous versions.
      
        Some devices are designed to deny users access to install or run
      modified versions of the software inside them, although the manufacturer
      can do so.  This is fundamentally incompatible with the aim of
      protecting users' freedom to change the software.  The systematic
      pattern of such abuse occurs in the area of products for individuals to
      use, which is precisely where it is most unacceptable.  Therefore, we
      have designed this version of the GPL to prohibit the practice for those
      products.  If such problems arise substantially in other domains, we
      stand ready to extend this provision to those domains in future versions
      of the GPL, as needed to protect the freedom of users.
      
        Finally, every program is threatened constantly by software patents.
      States should not allow patents to restrict development and use of
      software on general-purpose computers, but in those that do, we wish to
      avoid the special danger that patents applied to a free program could
      make it effectively proprietary.  To prevent this, the GPL assures that
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                  How to Apply These Terms to Your New Programs
      
        If you develop a new program, and you want it to be of the greatest
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          This is free software, and you are welcome to redistribute it
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      The hypothetical commands `show w' and `show c' should show the appropriate
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        The GNU General Public License does not permit incorporating your program
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      may consider it more useful to permit linking proprietary applications with
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      <http://www.gnu.org/philosophy/why-not-lgpl.html>.
      
      */

      File 3 of 4: StargateEthVault
      // 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 ^0.7.6;
      import "@openzeppelin/contracts/access/Ownable.sol";
      import "@openzeppelin/contracts/utils/ReentrancyGuard.sol";
      import "./interfaces/IStargateEthVault.sol";
      // This contract always UNWRAPS the erc20 for native gas token on transfer + transferFrom.
      // If you wish to disable the transfer auto-unwrap, you can specify _to addresses with `setNoUnwrapTo`
      contract StargateEthVault is IStargateEthVault, Ownable, ReentrancyGuard {
          string public constant name     = "Stargate Ether Vault";
          string public constant symbol   = "SGETH";
          uint8  public constant decimals = 18;
          uint256 public totalSupply;
          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);
          event TransferNative(address indexed src, address indexed dst, uint wad);
          mapping (address => uint)                       public  balanceOf;
          mapping (address => mapping (address => uint))  public  allowance;
          mapping (address => bool)                       public  noUnwrapTo;
          // if you do NOT wish to unwrap eth on transfers TO certain addresses
          function setNoUnwrapTo(address _addr) external onlyOwner {
              noUnwrapTo[_addr] = true;
          }
          function deposit() public payable override {
              balanceOf[msg.sender] += msg.value;
              totalSupply += msg.value;
              emit Deposit(msg.sender, msg.value);
          }
          function withdraw(uint wad) external override {
              require(balanceOf[msg.sender] >= wad);
              balanceOf[msg.sender] -= wad;
              msg.sender.transfer(wad);
              totalSupply -= wad;
              emit Withdrawal(msg.sender, wad);
          }
          function approve(address guy, uint wad) external override returns (bool) {
              allowance[msg.sender][guy] = wad;
              emit Approval(msg.sender, guy, wad);
              return true;
          }
          function transfer(address dst, uint wad) external override returns (bool) {
              return transferFrom(msg.sender, dst, wad);
          }
          function transferFrom(address src, address dst, uint wad) public override nonReentrant 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;
              }
              // always decrement the src (payer) address
              balanceOf[src] -= wad;
              if(noUnwrapTo[dst]){
                  // we do *not* unwrap
                  balanceOf[dst] += wad;
                  emit Transfer(src, dst, wad);
              } else {
                  // unwrap and send native gas token
                  totalSupply -= wad; // if its getting unwrapped, decrement the totalSupply
                  (bool success, ) = dst.call{value: wad}("");
                  require(success, "SGETH: failed to transfer");
                  emit TransferNative(src, dst, wad);
              }
              return true;
          }
          function renounceOwnership() public override onlyOwner {}
          receive() external payable {
              deposit();
          }
      }
      // SPDX-License-Identifier: MIT
      pragma solidity ^0.7.0;
      import "../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.
       *
       * By default, the owner account will be the one that deploys the contract. 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;
          event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
          /**
           * @dev Initializes the contract setting the deployer as the initial owner.
           */
          constructor () {
              address msgSender = _msgSender();
              _owner = msgSender;
              emit OwnershipTransferred(address(0), msgSender);
          }
          /**
           * @dev Returns the address of the current owner.
           */
          function owner() public view virtual returns (address) {
              return _owner;
          }
          /**
           * @dev Throws if called by any account other than the owner.
           */
          modifier onlyOwner() {
              require(owner() == _msgSender(), "Ownable: caller is not the owner");
              _;
          }
          /**
           * @dev Leaves the contract without owner. It will not be possible to call
           * `onlyOwner` functions anymore. Can only be called by the current owner.
           *
           * NOTE: Renouncing ownership will leave the contract without an owner,
           * thereby removing any functionality that is only available to the owner.
           */
          function renounceOwnership() public virtual onlyOwner {
              emit OwnershipTransferred(_owner, address(0));
              _owner = 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 {
              require(newOwner != address(0), "Ownable: new owner is the zero address");
              emit OwnershipTransferred(_owner, newOwner);
              _owner = newOwner;
          }
      }
      // SPDX-License-Identifier: MIT
      pragma solidity ^0.7.0;
      /**
       * @dev Contract module that helps prevent reentrant calls to a function.
       *
       * Inheriting from `ReentrancyGuard` will make the {nonReentrant} modifier
       * available, which can be applied to functions to make sure there are no nested
       * (reentrant) calls to them.
       *
       * Note that because there is a single `nonReentrant` guard, functions marked as
       * `nonReentrant` may not call one another. This can be worked around by making
       * those functions `private`, and then adding `external` `nonReentrant` entry
       * points to them.
       *
       * TIP: If you would like to learn more about reentrancy and alternative ways
       * to protect against it, check out our blog post
       * https://blog.openzeppelin.com/reentrancy-after-istanbul/[Reentrancy After Istanbul].
       */
      abstract contract ReentrancyGuard {
          // Booleans are more expensive than uint256 or any type that takes up a full
          // word because each write operation emits an extra SLOAD to first read the
          // slot's contents, replace the bits taken up by the boolean, and then write
          // back. This is the compiler's defense against contract upgrades and
          // pointer aliasing, and it cannot be disabled.
          // The values being non-zero value makes deployment a bit more expensive,
          // but in exchange the refund on every call to nonReentrant will be lower in
          // amount. Since refunds are capped to a percentage of the total
          // transaction's gas, it is best to keep them low in cases like this one, to
          // increase the likelihood of the full refund coming into effect.
          uint256 private constant _NOT_ENTERED = 1;
          uint256 private constant _ENTERED = 2;
          uint256 private _status;
          constructor () {
              _status = _NOT_ENTERED;
          }
          /**
           * @dev Prevents a contract from calling itself, directly or indirectly.
           * Calling a `nonReentrant` function from another `nonReentrant`
           * function is not supported. It is possible to prevent this from happening
           * by making the `nonReentrant` function external, and make it call a
           * `private` function that does the actual work.
           */
          modifier nonReentrant() {
              // On the first call to nonReentrant, _notEntered will be true
              require(_status != _ENTERED, "ReentrancyGuard: reentrant call");
              // Any calls to nonReentrant after this point will fail
              _status = _ENTERED;
              _;
              // By storing the original value once again, a refund is triggered (see
              // https://eips.ethereum.org/EIPS/eip-2200)
              _status = _NOT_ENTERED;
          }
      }
      pragma solidity 0.7.6;
      interface IStargateEthVault {
          function deposit() external payable;
          function transfer(address to, uint value) external returns (bool);
          function withdraw(uint) external;
          function approve(address guy, uint wad) external returns (bool);
          function transferFrom(address src, address dst, uint wad) external returns (bool);
      }// SPDX-License-Identifier: MIT
      pragma solidity >=0.6.0 <0.8.0;
      /*
       * @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 GSN 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 payable) {
              return msg.sender;
          }
          function _msgData() internal view virtual returns (bytes memory) {
              this; // silence state mutability warning without generating bytecode - see https://github.com/ethereum/solidity/issues/2691
              return msg.data;
          }
      }
      

      File 4 of 4: StargateComposer
      // SPDX-License-Identifier: UNLICENSED
      pragma solidity 0.7.6;
      pragma abicoder v2;
      import "@openzeppelin/contracts/utils/ReentrancyGuard.sol";
      import "@openzeppelin/contracts/access/Ownable.sol";
      import "@openzeppelin/contracts/utils/Address.sol";
      import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
      import "@openzeppelin/contracts/token/ERC20/SafeERC20.sol";
      import "@openzeppelin/contracts/math/SafeMath.sol";
      import "./interfaces/IStargateRouter.sol";
      import "./interfaces/IStargateReceiver.sol";
      import "./interfaces/IStargateEthVault.sol";
      import "./util/BytesLib.sol";
      import "./util/SafeCall.sol";
      interface IStargateBridge {
          function quoteLayerZeroFee(
              uint16 _chainId,
              uint8 _functionType,
              bytes calldata _toAddress,
              bytes calldata _transferAndCallPayload,
              IStargateRouter.lzTxObj memory _lzTxParams
          ) external view returns (uint256, uint256);
      }
      interface IPool {
          function token() external view returns (address);
          function convertRate() external view returns (uint256);
      }
      interface IStargateFactory {
          function getPool(uint256 _poolId) external view returns (address);
      }
      contract StargateComposer is IStargateRouter, IStargateReceiver, Ownable, ReentrancyGuard {
          using BytesLib for bytes;
          using SafeCall for address;
          using Address for address;
          using SafeERC20 for IERC20;
          using SafeMath for uint256;
          bytes4 private constant SELECTOR = bytes4(keccak256(bytes("transfer(address,uint256)")));
          uint256 private constant _NOT_ENTERED = 1;
          uint256 private constant _ENTERED = 2;
          uint256 private dstGasReserve = 40000;
          uint256 private transferOverhead = 20000;
          uint256 private _swapStatus = _NOT_ENTERED;
          IStargateBridge public immutable stargateBridge;
          IStargateRouter public immutable stargateRouter;
          address public immutable factory;
          uint256 public wethPoolId;
          struct PoolInfo {
              address token;
              address poolAddress;
              uint256 convertRate;
          }
          mapping(uint16 => address) public peers;
          mapping(uint256 => address) public stargateEthVaults;
          mapping(uint16 => mapping(bytes => mapping(uint256 => bytes32))) public payloadHashes;
          mapping(uint256 => PoolInfo) public poolIdToInfo; // cache pool info
          modifier nonSwapReentrant() {
              require(_swapStatus != _ENTERED, "Stargate: reentrant call");
              _swapStatus = _ENTERED;
              _;
              _swapStatus = _NOT_ENTERED;
          }
          event CachedSwapSaved(
              uint16 chainId,
              bytes srcAddress,
              uint256 nonce,
              bytes reason
          );
          event ComposedTokenTransferFailed(
              address token,
              address intendedReceiver,
              uint amountLD
          );
          struct SwapAmount {
              uint256 amountLD; // the amount, in Local Decimals, to be swapped
              uint256 minAmountLD; // the minimum amount accepted out on destination
          }
          constructor(address _stargateBridge, address _stargateRouter, address _stargateEthVault, uint256 _wethPoolId) {
              stargateBridge = IStargateBridge(_stargateBridge);
              stargateRouter = IStargateRouter(_stargateRouter);
              wethPoolId = _wethPoolId;
              setStargateEthVaults(_wethPoolId, _stargateEthVault);
              (bool success, bytes memory data) = _stargateRouter.staticcall(abi.encodeWithSignature("factory()"));
              require(success, "Stargate: invalid factory address");
              factory = abi.decode(data, (address));
          }
          function addLiquidity(
              uint256 _poolId,
              uint256 _amountLD,
              address _to
          ) external override {
              PoolInfo memory poolInfo = _getPoolInfo(_poolId);
              // remove dust
              if (poolInfo.convertRate > 1) _amountLD = _amountLD.div(poolInfo.convertRate).mul(poolInfo.convertRate);
              // transfer tokens into this contract
              IERC20(poolInfo.token).safeTransferFrom(msg.sender, address(this), _amountLD);
              stargateRouter.addLiquidity(_poolId, _amountLD, _to);
          }
          function redeemRemote(
              uint16 _dstChainId,
              uint256 _srcPoolId,
              uint256 _dstPoolId,
              address payable _refundAddress,
              uint256 _amountLP,
              uint256 _minAmountLD,
              bytes calldata _to,
              lzTxObj memory _lzTxParams
          ) external override payable nonReentrant {
              IERC20 lpToken = IERC20(_getPoolInfo(_srcPoolId).poolAddress);
              // transfer lp tokens into this contract
              lpToken.safeTransferFrom(msg.sender, address(this), _amountLP);
              stargateRouter.redeemRemote{value: msg.value}(
                  _dstChainId,
                  _srcPoolId,
                  _dstPoolId,
                  _refundAddress,
                  _amountLP,
                  _minAmountLD,
                  _to,
                  _lzTxParams
              );
          }
          function redeemLocal(
              uint16 _dstChainId,
              uint256 _srcPoolId,
              uint256 _dstPoolId,
              address payable _refundAddress,
              uint256 _amountLP,
              bytes calldata _to,
              lzTxObj memory _lzTxParams
          ) external override payable nonReentrant {
              IERC20 lpToken = IERC20(_getPoolInfo(_srcPoolId).poolAddress);
              // transfer lp tokens into this contract
              lpToken.safeTransferFrom(msg.sender, address(this), _amountLP);
              stargateRouter.redeemLocal{value: msg.value}(
                  _dstChainId,
                  _srcPoolId,
                  _dstPoolId,
                  _refundAddress,
                  _amountLP,
                  _to,
                  _lzTxParams
              );
          }
          function instantRedeemLocal(
              uint16 _srcPoolId,
              uint256 _amountLP,
              address _to
          ) external override nonReentrant returns (uint256 amountSD) {
              IERC20 lpToken = IERC20(_getPoolInfo(_srcPoolId).poolAddress);
              // should always be zero as this contract doesnt hold tokens
              uint balanceBefore = lpToken.balanceOf(address(this));
              // transfer lp tokens into this contract
              lpToken.safeTransferFrom(msg.sender, address(this), _amountLP);
              // redeem the tokens on behalf of user
              amountSD = stargateRouter.instantRedeemLocal(_srcPoolId, _amountLP, _to);
              // any extra lpTokens send back to the original msg.sender
              uint balanceAfter = lpToken.balanceOf(address(this));
              uint diff = balanceAfter - balanceBefore;
              if (diff > 0) lpToken.safeTransfer(msg.sender, diff);
          }
          function sendCredits(
              uint16 _dstChainId,
              uint256 _srcPoolId,
              uint256 _dstPoolId,
              address payable _refundAddress
          ) external payable override nonReentrant {
              stargateRouter.sendCredits{value: msg.value}(_dstChainId, _srcPoolId, _dstPoolId, _refundAddress);
          }
          function quoteLayerZeroFee(
              uint16 _chainId,
              uint8 _functionType,
              bytes calldata _toAddress,
              bytes calldata _transferAndCallPayload,
              IStargateRouter.lzTxObj memory _lzTxParams
          ) external view override returns(uint256, uint256) {
              bytes memory newPayload = _buildPayload(_toAddress, _transferAndCallPayload);
              // overhead for calling composer's sgReceive()
              _lzTxParams.dstGasForCall += dstGasReserve + transferOverhead;
              return stargateBridge.quoteLayerZeroFee(_chainId, _functionType, _toAddress, newPayload, _lzTxParams);
          }
          function swap(
              uint16 _dstChainId,
              uint256 _srcPoolId,
              uint256 _dstPoolId,
              address payable _refundAddress,
              uint256 _amountLD,
              uint256 _minAmountLD,
              IStargateRouter.lzTxObj memory _lzTxParams,
              bytes calldata _to,
              bytes calldata _payload
          ) external override payable nonSwapReentrant {
              bytes memory newPayload = _buildPayload(_to, _payload);
              bytes memory peer = _getPeer(_dstChainId);
              if(isEthPool(_srcPoolId)) {
                  require(msg.value > _amountLD, "Stargate: msg.value must be > _swapAmount.amountLD");
                  IStargateEthVault(stargateEthVaults[_srcPoolId]).deposit{value: _amountLD}();
                  IStargateEthVault(stargateEthVaults[_srcPoolId]).approve(address(stargateRouter), _amountLD);
              } else {
                  PoolInfo memory poolInfo = _getPoolInfo(_srcPoolId);
                  // remove dust
                  if (poolInfo.convertRate > 1) _amountLD = _amountLD.div(poolInfo.convertRate).mul(poolInfo.convertRate);
                  // transfer token to this contract
                  IERC20(poolInfo.token).safeTransferFrom(msg.sender, address(this), _amountLD);
              }
              // overhead for calling composer's sgReceive()
              _lzTxParams.dstGasForCall += dstGasReserve + transferOverhead;
              stargateRouter.swap{value: isEthPool(_srcPoolId) ? msg.value - _amountLD : msg.value}(
                  _dstChainId,
                  _srcPoolId,
                  _dstPoolId,
                  _refundAddress,
                  _amountLD,
                  _minAmountLD,
                  _lzTxParams,
                  peer, // swap the to address with the peer address
                  newPayload
              );
          }
          // @notice compose stargate to swap ETH on the source to ETH on the destination and arbitrary call
          function swapETHAndCall(
              uint16 _dstChainId, // destination Stargate chainId
              address payable _refundAddress, // refund additional messageFee to this address
              bytes calldata _to, // the receiver of the destination ETH
              SwapAmount memory _swapAmount, // the amount and the minimum swap amount
              IStargateRouter.lzTxObj memory _lzTxParams, // the LZ tx params
              bytes calldata _payload // the payload to send to the destination
          ) external payable nonSwapReentrant {
              bytes memory newPayload = _buildPayload(_to, _payload);
              bytes memory peer = _getPeer(_dstChainId);
              {
                  require(msg.value > _swapAmount.amountLD, "Stargate: msg.value must be > _swapAmount.amountLD");
                  require(stargateEthVaults[wethPoolId] != address(0), "Stargate: Pool does not exist");
                  IStargateEthVault(stargateEthVaults[wethPoolId]).deposit{value: _swapAmount.amountLD}();
                  IStargateEthVault(stargateEthVaults[wethPoolId]).approve(address(stargateRouter), _swapAmount.amountLD);
              }
              // overhead for calling composer's sgReceive()
              _lzTxParams.dstGasForCall += dstGasReserve + transferOverhead;
              stargateRouter.swap{value: (msg.value - _swapAmount.amountLD)}(
                  _dstChainId, // destination Stargate chainId
                  wethPoolId, // WETH Stargate poolId on source
                  wethPoolId, // WETH Stargate poolId on destination
                  _refundAddress, // message refund address if overpaid
                  _swapAmount.amountLD, // the amount in Local Decimals to swap()
                  _swapAmount.minAmountLD, // the minimum amount swap()er would allow to get out (ie: slippage)
                  _lzTxParams, // the LZ tx params
                  peer, // address on destination to send to
                  newPayload // payload to send to the destination
              );
          }
          function _buildPayload(
              bytes calldata _to,
              bytes calldata _payload
          ) internal view returns (bytes memory) {
              require(_to.length == 20, "Stargate: invalid to address");
              require(_payload.length > 0, "Stargate: payload is empty");
              // new payload = to(20) + sender(20) + payload
              // encoding the sender allows the receiver to know who called the Stargate
              return abi.encodePacked(_to, msg.sender, _payload);
          }
          function _getPeer(uint16 _dstChainId) internal view returns(bytes memory) {
              address peerAddr = peers[_dstChainId];
              require(peerAddr != address(0), "Stargate: peer not found");
              return abi.encodePacked(peerAddr);
          }
          function addLiquidityETH() external payable {
              require(msg.value > 0, "Stargate: msg.value is 0");
              // wrap the ETH into WETH
              uint256 amountLD = msg.value;
              require(stargateEthVaults[wethPoolId] != address(0), "Stargate: Pool does not exist");
              IStargateEthVault(stargateEthVaults[wethPoolId]).deposit{value: amountLD}();
              IStargateEthVault(stargateEthVaults[wethPoolId]).approve(address(stargateRouter), amountLD);
              // addLiquidity using the WETH that was just wrapped,
              // and mint the LP token to the msg.sender
              stargateRouter.addLiquidity(wethPoolId, amountLD, msg.sender);
          }
          function sgReceive(
              uint16 _srcChainId,
              bytes memory _srcAddress,
              uint256 _nonce,
              address _token,
              uint256 _amountLD,
              bytes memory _payload
          ) external override {
              require(msg.sender == address(stargateRouter), "Stargate: only router");
              // will just ignore the payload in some invalid configuration
              if (_payload.length <= 40) return; // 20 + 20 + payload
              address intendedReceiver = _payload.toAddress(0);
              try IERC20(_token).transfer(intendedReceiver, _amountLD) {
                  if (!intendedReceiver.isContract()) return; // ignore
                  bytes memory callData = abi.encodeWithSelector(
                      IStargateReceiver.sgReceive.selector,
                      _srcChainId,
                      abi.encodePacked(_payload.toAddress(20)), // use the caller as the srcAddress (the msg.sender caller the StargateComposer at the source)
                      _nonce,
                      _token,
                      _amountLD,
                      _payload.slice(40, _payload.length - 40)
                  );
                  // no point in requires, because it will revert regardless
                  uint256 externalGas = gasleft() - dstGasReserve;
                  (bool success, bytes memory reason) = intendedReceiver.safeCall(externalGas, 0, 150, callData); // only return 150 bytes of data
                  if (!success) {
                      payloadHashes[_srcChainId][_srcAddress][_nonce] = keccak256(abi.encodePacked(intendedReceiver, callData));
                      emit CachedSwapSaved(_srcChainId, _srcAddress, _nonce, reason);
                  }
              } catch {
                  // do nothing, token swap failed and can't be delivered, tokens are held inside this contract
                  emit ComposedTokenTransferFailed(_token, intendedReceiver, _amountLD);
              }
          }
          function clearCachedSwap(
              uint16 _srcChainId,
              bytes calldata _srcAddress,
              uint64 _nonce,
              address _receiver,
              bytes calldata _sgReceiveCallData
          ) external nonReentrant {
              bytes32 hash = keccak256(abi.encodePacked(_receiver, _sgReceiveCallData));
              require(payloadHashes[_srcChainId][_srcAddress][_nonce] == hash, "Stargate: invalid hash");
              delete payloadHashes[_srcChainId][_srcAddress][_nonce];
              (bool success, bytes memory reason) = _receiver.safeCall(gasleft(), 0, 150, _sgReceiveCallData);
              if (!success) {
                  assembly {
                      revert(add(32, reason), mload(reason))
                  }
              }
          }
          function setDstGasReserve(uint256 _dstGasReserve) onlyOwner external {
              dstGasReserve = _dstGasReserve;
          }
          function setTransferOverhead(uint256 _transferOverhead) onlyOwner external {
              transferOverhead = _transferOverhead;
          }
          function setStargateEthVaults(uint256 _poolId, address _stargateEthVault) onlyOwner public {
              stargateEthVaults[_poolId] = _stargateEthVault;
          }
          function setWethPoolId(uint256 _wethPoolId) onlyOwner external {
              wethPoolId = _wethPoolId;
          }
          function setPeer(uint16 _chainId, address _peer) onlyOwner external {
              require(peers[_chainId] == address(0), "Stargate: peer already set");
              peers[_chainId] = _peer;
          }
          function recoverToken(address _token, address _to, uint256 _amount) external onlyOwner {
              IERC20(_token).safeTransfer(_to, _amount);
          }
          function isSending() external view returns (bool) {
              return _swapStatus == _ENTERED;
          }
          function isEthPool(uint256 _srcPoolId) internal view returns (bool) {
              return stargateEthVaults[_srcPoolId] != address(0);
          }
          function getPoolInfo(uint256 _poolId) external returns (PoolInfo memory poolInfo) {
              return _getPoolInfo(_poolId);
          }
          function _getPoolInfo(uint256 _poolId) internal returns (PoolInfo memory poolInfo) {
              // return early if its already been called
              if (poolIdToInfo[_poolId].poolAddress != address(0)) {
                  return poolIdToInfo[_poolId];
              }
              address pool = IStargateFactory(factory).getPool(_poolId);
              require(address(pool) != address(0), "Stargate: pool does not exist");
              IERC20(pool).safeApprove(address(stargateRouter), type(uint256).max);
              address token = IPool(pool).token();
              require(address(token) != address(0), "Stargate: token does not exist");
              IERC20(token).safeApprove(address(stargateRouter), type(uint256).max);
              uint256 convertRate = IPool(pool).convertRate();
              poolInfo = PoolInfo({token: token, poolAddress: pool, convertRate: convertRate});
              poolIdToInfo[_poolId] = poolInfo;
          }
      }
      // SPDX-License-Identifier: MIT
      pragma solidity >=0.6.0 <0.8.0;
      /*
       * @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 GSN 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 payable) {
              return msg.sender;
          }
          function _msgData() internal view virtual returns (bytes memory) {
              this; // silence state mutability warning without generating bytecode - see https://github.com/ethereum/solidity/issues/2691
              return msg.data;
          }
      }
      // SPDX-License-Identifier: MIT
      pragma solidity ^0.7.0;
      /**
       * @dev Contract module that helps prevent reentrant calls to a function.
       *
       * Inheriting from `ReentrancyGuard` will make the {nonReentrant} modifier
       * available, which can be applied to functions to make sure there are no nested
       * (reentrant) calls to them.
       *
       * Note that because there is a single `nonReentrant` guard, functions marked as
       * `nonReentrant` may not call one another. This can be worked around by making
       * those functions `private`, and then adding `external` `nonReentrant` entry
       * points to them.
       *
       * TIP: If you would like to learn more about reentrancy and alternative ways
       * to protect against it, check out our blog post
       * https://blog.openzeppelin.com/reentrancy-after-istanbul/[Reentrancy After Istanbul].
       */
      abstract contract ReentrancyGuard {
          // Booleans are more expensive than uint256 or any type that takes up a full
          // word because each write operation emits an extra SLOAD to first read the
          // slot's contents, replace the bits taken up by the boolean, and then write
          // back. This is the compiler's defense against contract upgrades and
          // pointer aliasing, and it cannot be disabled.
          // The values being non-zero value makes deployment a bit more expensive,
          // but in exchange the refund on every call to nonReentrant will be lower in
          // amount. Since refunds are capped to a percentage of the total
          // transaction's gas, it is best to keep them low in cases like this one, to
          // increase the likelihood of the full refund coming into effect.
          uint256 private constant _NOT_ENTERED = 1;
          uint256 private constant _ENTERED = 2;
          uint256 private _status;
          constructor () {
              _status = _NOT_ENTERED;
          }
          /**
           * @dev Prevents a contract from calling itself, directly or indirectly.
           * Calling a `nonReentrant` function from another `nonReentrant`
           * function is not supported. It is possible to prevent this from happening
           * by making the `nonReentrant` function external, and make it call a
           * `private` function that does the actual work.
           */
          modifier nonReentrant() {
              // On the first call to nonReentrant, _notEntered will be true
              require(_status != _ENTERED, "ReentrancyGuard: reentrant call");
              // Any calls to nonReentrant after this point will fail
              _status = _ENTERED;
              _;
              // By storing the original value once again, a refund is triggered (see
              // https://eips.ethereum.org/EIPS/eip-2200)
              _status = _NOT_ENTERED;
          }
      }
      // SPDX-License-Identifier: MIT
      pragma solidity ^0.7.0;
      import "../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.
       *
       * By default, the owner account will be the one that deploys the contract. 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;
          event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
          /**
           * @dev Initializes the contract setting the deployer as the initial owner.
           */
          constructor () {
              address msgSender = _msgSender();
              _owner = msgSender;
              emit OwnershipTransferred(address(0), msgSender);
          }
          /**
           * @dev Returns the address of the current owner.
           */
          function owner() public view virtual returns (address) {
              return _owner;
          }
          /**
           * @dev Throws if called by any account other than the owner.
           */
          modifier onlyOwner() {
              require(owner() == _msgSender(), "Ownable: caller is not the owner");
              _;
          }
          /**
           * @dev Leaves the contract without owner. It will not be possible to call
           * `onlyOwner` functions anymore. Can only be called by the current owner.
           *
           * NOTE: Renouncing ownership will leave the contract without an owner,
           * thereby removing any functionality that is only available to the owner.
           */
          function renounceOwnership() public virtual onlyOwner {
              emit OwnershipTransferred(_owner, address(0));
              _owner = 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 {
              require(newOwner != address(0), "Ownable: new owner is the zero address");
              emit OwnershipTransferred(_owner, newOwner);
              _owner = newOwner;
          }
      }
      // SPDX-License-Identifier: MIT
      pragma solidity ^0.7.0;
      /**
       * @dev Collection of functions related to the address type
       */
      library Address {
          /**
           * @dev Returns true if `account` is a contract.
           *
           * [IMPORTANT]
           * ====
           * It is unsafe to assume that an address for which this function returns
           * false is an externally-owned account (EOA) and not a contract.
           *
           * Among others, `isContract` will return false for the following
           * types of addresses:
           *
           *  - an externally-owned account
           *  - a contract in construction
           *  - an address where a contract will be created
           *  - an address where a contract lived, but was destroyed
           * ====
           */
          function isContract(address account) internal view returns (bool) {
              // This method relies on extcodesize, which returns 0 for contracts in
              // construction, since the code is only stored at the end of the
              // constructor execution.
              uint256 size;
              // solhint-disable-next-line no-inline-assembly
              assembly { size := extcodesize(account) }
              return size > 0;
          }
          /**
           * @dev Replacement for Solidity's `transfer`: sends `amount` wei to
           * `recipient`, forwarding all available gas and reverting on errors.
           *
           * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
           * of certain opcodes, possibly making contracts go over the 2300 gas limit
           * imposed by `transfer`, making them unable to receive funds via
           * `transfer`. {sendValue} removes this limitation.
           *
           * https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].
           *
           * IMPORTANT: because control is transferred to `recipient`, care must be
           * taken to not create reentrancy vulnerabilities. Consider using
           * {ReentrancyGuard} or the
           * https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
           */
          function sendValue(address payable recipient, uint256 amount) internal {
              require(address(this).balance >= amount, "Address: insufficient balance");
              // solhint-disable-next-line avoid-low-level-calls, avoid-call-value
              (bool success, ) = recipient.call{ value: amount }("");
              require(success, "Address: unable to send value, recipient may have reverted");
          }
          /**
           * @dev Performs a Solidity function call using a low level `call`. A
           * plain`call` is an unsafe replacement for a function call: use this
           * function instead.
           *
           * If `target` reverts with a revert reason, it is bubbled up by this
           * function (like regular Solidity function calls).
           *
           * Returns the raw returned data. To convert to the expected return value,
           * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
           *
           * Requirements:
           *
           * - `target` must be a contract.
           * - calling `target` with `data` must not revert.
           *
           * _Available since v3.1._
           */
          function functionCall(address target, bytes memory data) internal returns (bytes memory) {
            return functionCall(target, data, "Address: low-level call failed");
          }
          /**
           * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with
           * `errorMessage` as a fallback revert reason when `target` reverts.
           *
           * _Available since v3.1._
           */
          function functionCall(address target, bytes memory data, string memory errorMessage) internal returns (bytes memory) {
              return functionCallWithValue(target, data, 0, errorMessage);
          }
          /**
           * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
           * but also transferring `value` wei to `target`.
           *
           * Requirements:
           *
           * - the calling contract must have an ETH balance of at least `value`.
           * - the called Solidity function must be `payable`.
           *
           * _Available since v3.1._
           */
          function functionCallWithValue(address target, bytes memory data, uint256 value) internal returns (bytes memory) {
              return functionCallWithValue(target, data, value, "Address: low-level call with value failed");
          }
          /**
           * @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but
           * with `errorMessage` as a fallback revert reason when `target` reverts.
           *
           * _Available since v3.1._
           */
          function functionCallWithValue(address target, bytes memory data, uint256 value, string memory errorMessage) internal returns (bytes memory) {
              require(address(this).balance >= value, "Address: insufficient balance for call");
              require(isContract(target), "Address: call to non-contract");
              // solhint-disable-next-line avoid-low-level-calls
              (bool success, bytes memory returndata) = target.call{ value: value }(data);
              return _verifyCallResult(success, returndata, errorMessage);
          }
          /**
           * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
           * but performing a static call.
           *
           * _Available since v3.3._
           */
          function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {
              return functionStaticCall(target, data, "Address: low-level static call failed");
          }
          /**
           * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
           * but performing a static call.
           *
           * _Available since v3.3._
           */
          function functionStaticCall(address target, bytes memory data, string memory errorMessage) internal view returns (bytes memory) {
              require(isContract(target), "Address: static call to non-contract");
              // solhint-disable-next-line avoid-low-level-calls
              (bool success, bytes memory returndata) = target.staticcall(data);
              return _verifyCallResult(success, returndata, errorMessage);
          }
          /**
           * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
           * but performing a delegate call.
           *
           * _Available since v3.4._
           */
          function functionDelegateCall(address target, bytes memory data) internal returns (bytes memory) {
              return functionDelegateCall(target, data, "Address: low-level delegate call failed");
          }
          /**
           * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
           * but performing a delegate call.
           *
           * _Available since v3.4._
           */
          function functionDelegateCall(address target, bytes memory data, string memory errorMessage) internal returns (bytes memory) {
              require(isContract(target), "Address: delegate call to non-contract");
              // solhint-disable-next-line avoid-low-level-calls
              (bool success, bytes memory returndata) = target.delegatecall(data);
              return _verifyCallResult(success, returndata, errorMessage);
          }
          function _verifyCallResult(bool success, bytes memory returndata, string memory errorMessage) private pure returns(bytes memory) {
              if (success) {
                  return returndata;
              } else {
                  // Look for revert reason and bubble it up if present
                  if (returndata.length > 0) {
                      // The easiest way to bubble the revert reason is using memory via assembly
                      // solhint-disable-next-line no-inline-assembly
                      assembly {
                          let returndata_size := mload(returndata)
                          revert(add(32, returndata), returndata_size)
                      }
                  } else {
                      revert(errorMessage);
                  }
              }
          }
      }
      // SPDX-License-Identifier: MIT
      pragma solidity ^0.7.0;
      /**
       * @dev Interface of the ERC20 standard as defined in the EIP.
       */
      interface IERC20 {
          /**
           * @dev Returns the amount of tokens in existence.
           */
          function totalSupply() external view returns (uint256);
          /**
           * @dev Returns the amount of tokens owned by `account`.
           */
          function balanceOf(address account) external view returns (uint256);
          /**
           * @dev Moves `amount` tokens from the caller's account to `recipient`.
           *
           * Returns a boolean value indicating whether the operation succeeded.
           *
           * Emits a {Transfer} event.
           */
          function transfer(address recipient, uint256 amount) 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 `amount` 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 amount) external returns (bool);
          /**
           * @dev Moves `amount` tokens from `sender` to `recipient` using the
           * allowance mechanism. `amount` is then deducted from the caller's
           * allowance.
           *
           * Returns a boolean value indicating whether the operation succeeded.
           *
           * Emits a {Transfer} event.
           */
          function transferFrom(address sender, address recipient, uint256 amount) external returns (bool);
          /**
           * @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);
      }
      // SPDX-License-Identifier: MIT
      pragma solidity ^0.7.0;
      import "./IERC20.sol";
      import "../../math/SafeMath.sol";
      import "../../utils/Address.sol";
      /**
       * @title SafeERC20
       * @dev Wrappers around ERC20 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 {
          using SafeMath for uint256;
          using Address for address;
          function safeTransfer(IERC20 token, address to, uint256 value) internal {
              _callOptionalReturn(token, abi.encodeWithSelector(token.transfer.selector, to, value));
          }
          function safeTransferFrom(IERC20 token, address from, address to, uint256 value) internal {
              _callOptionalReturn(token, abi.encodeWithSelector(token.transferFrom.selector, from, to, value));
          }
          /**
           * @dev Deprecated. This function has issues similar to the ones found in
           * {IERC20-approve}, and its usage is discouraged.
           *
           * Whenever possible, use {safeIncreaseAllowance} and
           * {safeDecreaseAllowance} instead.
           */
          function safeApprove(IERC20 token, address spender, uint256 value) internal {
              // safeApprove should only be called when setting an initial allowance,
              // or when resetting it to zero. To increase and decrease it, use
              // 'safeIncreaseAllowance' and 'safeDecreaseAllowance'
              // solhint-disable-next-line max-line-length
              require((value == 0) || (token.allowance(address(this), spender) == 0),
                  "SafeERC20: approve from non-zero to non-zero allowance"
              );
              _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, value));
          }
          function safeIncreaseAllowance(IERC20 token, address spender, uint256 value) internal {
              uint256 newAllowance = token.allowance(address(this), spender).add(value);
              _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
          }
          function safeDecreaseAllowance(IERC20 token, address spender, uint256 value) internal {
              uint256 newAllowance = token.allowance(address(this), spender).sub(value, "SafeERC20: decreased allowance below zero");
              _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
          }
          /**
           * @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).
           */
          function _callOptionalReturn(IERC20 token, bytes memory data) private {
              // We need to perform a low level call here, to bypass Solidity's return data size checking mechanism, since
              // we're implementing it ourselves. We use {Address.functionCall} to perform this call, which verifies that
              // the target address contains contract code and also asserts for success in the low-level call.
              bytes memory returndata = address(token).functionCall(data, "SafeERC20: low-level call failed");
              if (returndata.length > 0) { // Return data is optional
                  // solhint-disable-next-line max-line-length
                  require(abi.decode(returndata, (bool)), "SafeERC20: ERC20 operation did not succeed");
              }
          }
      }
      // SPDX-License-Identifier: MIT
      pragma solidity ^0.7.0;
      /**
       * @dev Wrappers over Solidity's arithmetic operations with added overflow
       * checks.
       *
       * Arithmetic operations in Solidity wrap on overflow. This can easily result
       * in bugs, because programmers usually assume that an overflow raises an
       * error, which is the standard behavior in high level programming languages.
       * `SafeMath` restores this intuition by reverting the transaction when an
       * operation overflows.
       *
       * Using this library instead of the unchecked operations eliminates an entire
       * class of bugs, so it's recommended to use it always.
       */
      library SafeMath {
          /**
           * @dev Returns the addition of two unsigned integers, with an overflow flag.
           *
           * _Available since v3.4._
           */
          function tryAdd(uint256 a, uint256 b) internal pure returns (bool, uint256) {
              uint256 c = a + b;
              if (c < a) return (false, 0);
              return (true, c);
          }
          /**
           * @dev Returns the substraction of two unsigned integers, with an overflow flag.
           *
           * _Available since v3.4._
           */
          function trySub(uint256 a, uint256 b) internal pure returns (bool, uint256) {
              if (b > a) return (false, 0);
              return (true, a - b);
          }
          /**
           * @dev Returns the multiplication of two unsigned integers, with an overflow flag.
           *
           * _Available since v3.4._
           */
          function tryMul(uint256 a, uint256 b) internal pure returns (bool, uint256) {
              // Gas optimization: this is cheaper than requiring 'a' not being zero, but the
              // benefit is lost if 'b' is also tested.
              // See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522
              if (a == 0) return (true, 0);
              uint256 c = a * b;
              if (c / a != b) return (false, 0);
              return (true, c);
          }
          /**
           * @dev Returns the division of two unsigned integers, with a division by zero flag.
           *
           * _Available since v3.4._
           */
          function tryDiv(uint256 a, uint256 b) internal pure returns (bool, uint256) {
              if (b == 0) return (false, 0);
              return (true, a / b);
          }
          /**
           * @dev Returns the remainder of dividing two unsigned integers, with a division by zero flag.
           *
           * _Available since v3.4._
           */
          function tryMod(uint256 a, uint256 b) internal pure returns (bool, uint256) {
              if (b == 0) return (false, 0);
              return (true, a % b);
          }
          /**
           * @dev Returns the addition of two unsigned integers, reverting on
           * overflow.
           *
           * Counterpart to Solidity's `+` operator.
           *
           * Requirements:
           *
           * - Addition cannot overflow.
           */
          function add(uint256 a, uint256 b) internal pure returns (uint256) {
              uint256 c = a + b;
              require(c >= a, "SafeMath: addition overflow");
              return c;
          }
          /**
           * @dev Returns the subtraction of two unsigned integers, reverting on
           * overflow (when the result is negative).
           *
           * Counterpart to Solidity's `-` operator.
           *
           * Requirements:
           *
           * - Subtraction cannot overflow.
           */
          function sub(uint256 a, uint256 b) internal pure returns (uint256) {
              require(b <= a, "SafeMath: subtraction overflow");
              return a - b;
          }
          /**
           * @dev Returns the multiplication of two unsigned integers, reverting on
           * overflow.
           *
           * Counterpart to Solidity's `*` operator.
           *
           * Requirements:
           *
           * - Multiplication cannot overflow.
           */
          function mul(uint256 a, uint256 b) internal pure returns (uint256) {
              if (a == 0) return 0;
              uint256 c = a * b;
              require(c / a == b, "SafeMath: multiplication overflow");
              return c;
          }
          /**
           * @dev Returns the integer division of two unsigned integers, reverting on
           * division by zero. The result is rounded towards zero.
           *
           * Counterpart to Solidity's `/` operator. Note: this function uses a
           * `revert` opcode (which leaves remaining gas untouched) while Solidity
           * uses an invalid opcode to revert (consuming all remaining gas).
           *
           * Requirements:
           *
           * - The divisor cannot be zero.
           */
          function div(uint256 a, uint256 b) internal pure returns (uint256) {
              require(b > 0, "SafeMath: division by zero");
              return a / b;
          }
          /**
           * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
           * reverting when dividing by zero.
           *
           * Counterpart to Solidity's `%` operator. This function uses a `revert`
           * opcode (which leaves remaining gas untouched) while Solidity uses an
           * invalid opcode to revert (consuming all remaining gas).
           *
           * Requirements:
           *
           * - The divisor cannot be zero.
           */
          function mod(uint256 a, uint256 b) internal pure returns (uint256) {
              require(b > 0, "SafeMath: modulo by zero");
              return a % b;
          }
          /**
           * @dev Returns the subtraction of two unsigned integers, reverting with custom message on
           * overflow (when the result is negative).
           *
           * CAUTION: This function is deprecated because it requires allocating memory for the error
           * message unnecessarily. For custom revert reasons use {trySub}.
           *
           * Counterpart to Solidity's `-` operator.
           *
           * Requirements:
           *
           * - Subtraction cannot overflow.
           */
          function sub(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
              require(b <= a, errorMessage);
              return a - b;
          }
          /**
           * @dev Returns the integer division of two unsigned integers, reverting with custom message on
           * division by zero. The result is rounded towards zero.
           *
           * CAUTION: This function is deprecated because it requires allocating memory for the error
           * message unnecessarily. For custom revert reasons use {tryDiv}.
           *
           * Counterpart to Solidity's `/` operator. Note: this function uses a
           * `revert` opcode (which leaves remaining gas untouched) while Solidity
           * uses an invalid opcode to revert (consuming all remaining gas).
           *
           * Requirements:
           *
           * - The divisor cannot be zero.
           */
          function div(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
              require(b > 0, errorMessage);
              return a / b;
          }
          /**
           * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
           * reverting with custom message when dividing by zero.
           *
           * CAUTION: This function is deprecated because it requires allocating memory for the error
           * message unnecessarily. For custom revert reasons use {tryMod}.
           *
           * Counterpart to Solidity's `%` operator. This function uses a `revert`
           * opcode (which leaves remaining gas untouched) while Solidity uses an
           * invalid opcode to revert (consuming all remaining gas).
           *
           * Requirements:
           *
           * - The divisor cannot be zero.
           */
          function mod(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
              require(b > 0, errorMessage);
              return a % b;
          }
      }
      // SPDX-License-Identifier: BUSL-1.1
      pragma solidity 0.7.6;
      pragma abicoder v2;
      interface IStargateRouter {
          struct lzTxObj {
              uint256 dstGasForCall;
              uint256 dstNativeAmount;
              bytes dstNativeAddr;
          }
          function addLiquidity(
              uint256 _poolId,
              uint256 _amountLD,
              address _to
          ) external;
          function swap(
              uint16 _dstChainId,
              uint256 _srcPoolId,
              uint256 _dstPoolId,
              address payable _refundAddress,
              uint256 _amountLD,
              uint256 _minAmountLD,
              lzTxObj memory _lzTxParams,
              bytes calldata _to,
              bytes calldata _payload
          ) external payable;
          function redeemRemote(
              uint16 _dstChainId,
              uint256 _srcPoolId,
              uint256 _dstPoolId,
              address payable _refundAddress,
              uint256 _amountLP,
              uint256 _minAmountLD,
              bytes calldata _to,
              lzTxObj memory _lzTxParams
          ) external payable;
          function instantRedeemLocal(
              uint16 _srcPoolId,
              uint256 _amountLP,
              address _to
          ) external returns (uint256);
          function redeemLocal(
              uint16 _dstChainId,
              uint256 _srcPoolId,
              uint256 _dstPoolId,
              address payable _refundAddress,
              uint256 _amountLP,
              bytes calldata _to,
              lzTxObj memory _lzTxParams
          ) external payable;
          function sendCredits(
              uint16 _dstChainId,
              uint256 _srcPoolId,
              uint256 _dstPoolId,
              address payable _refundAddress
          ) external payable;
          function quoteLayerZeroFee(
              uint16 _dstChainId,
              uint8 _functionType,
              bytes calldata _toAddress,
              bytes calldata _transferAndCallPayload,
              lzTxObj memory _lzTxParams
          ) external view returns (uint256, uint256);
      }
      // SPDX-License-Identifier: BUSL-1.1
      pragma solidity 0.7.6;
      interface IStargateReceiver {
          function sgReceive(
              uint16 _chainId,
              bytes memory _srcAddress,
              uint256 _nonce,
              address _token,
              uint256 amountLD,
              bytes memory payload
          ) external;
      }
      // SPDX-License-Identifier: BUSL-1.1
      pragma solidity 0.7.6;
      interface IStargateEthVault {
          function deposit() external payable;
          function transfer(address to, uint value) external returns (bool);
          function withdraw(uint) external;
          function approve(address guy, uint wad) external returns (bool);
          function transferFrom(
              address src,
              address dst,
              uint wad
          ) external returns (bool);
      }
      // SPDX-License-Identifier: Unlicense
      /*
       * @title Solidity Bytes Arrays Utils
       * @author Gonçalo Sá <[email protected]>
       *
       * @dev Bytes tightly packed arrays utility library for ethereum contracts written in Solidity.
       *      The library lets you concatenate, slice and type cast bytes arrays both in memory and storage.
       */
      pragma solidity >=0.7.0 <0.8.0;
      import "@openzeppelin/contracts/math/SafeMath.sol";
      library BytesLib {
          using SafeMath for uint256;
          function slice(bytes memory _bytes, uint256 _start, uint256 _length) internal pure returns (bytes memory) {
              require(_length.add(31) >= _length, "slice_overflow");
              require(_bytes.length >= _start.add(_length), "slice_outOfBounds");
              bytes memory tempBytes;
              assembly {
                  switch iszero(_length)
                  case 0 {
                      // Get a location of some free memory and store it in tempBytes as
                      // Solidity does for memory variables.
                      tempBytes := mload(0x40)
                      // The first word of the slice result is potentially a partial
                      // word read from the original array. To read it, we calculate
                      // the length of that partial word and start copying that many
                      // bytes into the array. The first word we copy will start with
                      // data we don't care about, but the last `lengthmod` bytes will
                      // land at the beginning of the contents of the new array. When
                      // we're done copying, we overwrite the full first word with
                      // the actual length of the slice.
                      let lengthmod := and(_length, 31)
                      // The multiplication in the next line is necessary
                      // because when slicing multiples of 32 bytes (lengthmod == 0)
                      // the following copy loop was copying the origin's length
                      // and then ending prematurely not copying everything it should.
                      let mc := add(add(tempBytes, lengthmod), mul(0x20, iszero(lengthmod)))
                      let end := add(mc, _length)
                      for {
                          // The multiplication in the next line has the same exact purpose
                          // as the one above.
                          let cc := add(add(add(_bytes, lengthmod), mul(0x20, iszero(lengthmod))), _start)
                      } lt(mc, end) {
                          mc := add(mc, 0x20)
                          cc := add(cc, 0x20)
                      } {
                          mstore(mc, mload(cc))
                      }
                      mstore(tempBytes, _length)
                      //update free-memory pointer
                      //allocating the array padded to 32 bytes like the compiler does now
                      mstore(0x40, and(add(mc, 31), not(31)))
                  }
                  //if we want a zero-length slice let's just return a zero-length array
                  default {
                      tempBytes := mload(0x40)
                      //zero out the 32 bytes slice we are about to return
                      //we need to do it because Solidity does not garbage collect
                      mstore(tempBytes, 0)
                      mstore(0x40, add(tempBytes, 0x20))
                  }
              }
              return tempBytes;
          }
          function toUint16(bytes memory _bytes, uint256 _start) internal pure returns (uint16) {
              require(_bytes.length >= _start.add(2), "toUint16_outOfBounds");
              uint16 tempUint;
              assembly {
                  tempUint := mload(add(add(_bytes, 0x2), _start))
              }
              return tempUint;
          }
          function toBytes32(bytes memory _bytes, uint256 _start) internal pure returns (bytes32) {
              require(_bytes.length >= _start.add(32), "toBytes32_outOfBounds");
              bytes32 tempBytes32;
              assembly {
                  tempBytes32 := mload(add(add(_bytes, 0x20), _start))
              }
              return tempBytes32;
          }
          function toAddress(bytes memory _bytes, uint256 _start) internal pure returns (address) {
              require(_bytes.length >= _start.add(20), "toAddress_outOfBounds");
              address tempAddress;
              assembly {
                  tempAddress := div(mload(add(add(_bytes, 0x20), _start)), 0x1000000000000000000000000)
              }
              return tempAddress;
          }
      }
      // SPDX-License-Identifier: BUSL-1.1
      pragma solidity 0.7.6;
      library SafeCall {
          /// @notice calls a contract with a specified gas limit and value and captures the return data
          /// @dev copied from https://github.com/nomad-xyz/ExcessivelySafeCall/blob/main/src/ExcessivelySafeCall.sol.
          /// @param _target The address to call
          /// @param _gas The amount of gas to forward to the remote contract
          /// @param _value The value in wei to send to the remote contract
          /// @param _maxCopy The maximum number of bytes of returndata to copy
          /// to memory.
          /// @param _calldata The data to send to the remote contract
          /// @return success and returndata, as `.call()`. Returndata is capped to
          /// `_maxCopy` bytes.
          function safeCall(
              address _target,
              uint256 _gas,
              uint256 _value,
              uint16 _maxCopy,
              bytes memory _calldata
          ) internal returns (bool, bytes memory) {
              // set up for assembly call
              uint256 _toCopy;
              bool _success;
              bytes memory _returnData = new bytes(_maxCopy);
              // dispatch message to recipient
              // by assembly calling "handle" function
              // we call via assembly to avoid memcopying a very large returndata
              // returned by a malicious contract
              assembly {
                  _success := call(
                      _gas, // gas
                      _target, // recipient
                      _value, // ether value
                      add(_calldata, 0x20), // inloc
                      mload(_calldata), // inlen
                      0, // outloc
                      0 // outlen
                  )
                  // limit our copy to 256 bytes
                  _toCopy := returndatasize()
                  if gt(_toCopy, _maxCopy) {
                      _toCopy := _maxCopy
                  }
                  // Store the length of the copied bytes
                  mstore(_returnData, _toCopy)
                  // copy the bytes from returndata[0:_toCopy]
                  returndatacopy(add(_returnData, 0x20), 0, _toCopy)
              }
              return (_success, _returnData);
          }
      }