ETH Price: $2,578.54 (-3.08%)

Transaction Decoder

Block:
8385753 at Aug-20-2019 06:52:44 AM +UTC
Transaction Fee:
0.001184012 ETH $3.05
Gas Used:
296,003 Gas / 4 Gwei

Emitted Events:

75 KnownOriginDigitalAssetV2.Transfer( _from=0x00000000...000000000, _to=[Sender] 0xd1898665a01a91ac10bd2c6cb1899336df34ac33, _tokenId=51537 )
76 KnownOriginDigitalAssetV2.Minted( _tokenId=51537, _editionNumber=51500, _buyer=[Sender] 0xd1898665a01a91ac10bd2c6cb1899336df34ac33 )
77 KnownOriginDigitalAssetV2.Purchase( _tokenId=51537, _editionNumber=51500, _buyer=[Sender] 0xd1898665a01a91ac10bd2c6cb1899336df34ac33, _priceInWei=0 )

Account State Difference:

  Address   Before After State Difference Code
(F2Pool Old)
2,845.755415981366625333 Eth2,845.756599993366625333 Eth0.001184012
0xD1898665...6df34AC33
0.011447128621383442 Eth
Nonce: 4
0.010263116621383442 Eth
Nonce: 5
0.001184012
0xFBeef911...D28174B7d

Execution Trace

KnownOriginDigitalAssetV2.purchase( _editionNumber=51500 ) => ( 51537 )
  • KnownOrigin: Admin.CALL( )
    pragma solidity ^0.4.24;
    
    // File: openzeppelin-solidity/contracts/access/rbac/Roles.sol
    
    /**
     * @title Roles
     * @author Francisco Giordano (@frangio)
     * @dev Library for managing addresses assigned to a Role.
     * See RBAC.sol for example usage.
     */
    library Roles {
      struct Role {
        mapping (address => bool) bearer;
      }
    
      /**
       * @dev give an address access to this role
       */
      function add(Role storage _role, address _addr)
        internal
      {
        _role.bearer[_addr] = true;
      }
    
      /**
       * @dev remove an address' access to this role
       */
      function remove(Role storage _role, address _addr)
        internal
      {
        _role.bearer[_addr] = false;
      }
    
      /**
       * @dev check if an address has this role
       * // reverts
       */
      function check(Role storage _role, address _addr)
        internal
        view
      {
        require(has(_role, _addr));
      }
    
      /**
       * @dev check if an address has this role
       * @return bool
       */
      function has(Role storage _role, address _addr)
        internal
        view
        returns (bool)
      {
        return _role.bearer[_addr];
      }
    }
    
    // File: contracts/v2/AccessControl.sol
    
    /**
     * @title Based on OpenZeppelin Whitelist & RBCA contracts
     * @dev The AccessControl contract provides different access for addresses, and provides basic authorization control functions.
     */
    contract AccessControl {
    
      using Roles for Roles.Role;
    
      uint8 public constant ROLE_KNOWN_ORIGIN = 1;
      uint8 public constant ROLE_MINTER = 2;
      uint8 public constant ROLE_UNDER_MINTER = 3;
    
      event RoleAdded(address indexed operator, uint8 role);
      event RoleRemoved(address indexed operator, uint8 role);
    
      address public owner;
    
      mapping(uint8 => Roles.Role) private roles;
    
      modifier onlyIfKnownOrigin() {
        require(msg.sender == owner || hasRole(msg.sender, ROLE_KNOWN_ORIGIN));
        _;
      }
    
      modifier onlyIfMinter() {
        require(msg.sender == owner || hasRole(msg.sender, ROLE_KNOWN_ORIGIN) || hasRole(msg.sender, ROLE_MINTER));
        _;
      }
    
      modifier onlyIfUnderMinter() {
        require(msg.sender == owner || hasRole(msg.sender, ROLE_KNOWN_ORIGIN) || hasRole(msg.sender, ROLE_UNDER_MINTER));
        _;
      }
    
      constructor() public {
        owner = msg.sender;
      }
    
      ////////////////////////////////////
      // Whitelist/RBCA Derived Methods //
      ////////////////////////////////////
    
      function addAddressToAccessControl(address _operator, uint8 _role)
      public
      onlyIfKnownOrigin
      {
        roles[_role].add(_operator);
        emit RoleAdded(_operator, _role);
      }
    
      function removeAddressFromAccessControl(address _operator, uint8 _role)
      public
      onlyIfKnownOrigin
      {
        roles[_role].remove(_operator);
        emit RoleRemoved(_operator, _role);
      }
    
      function checkRole(address _operator, uint8 _role)
      public
      view
      {
        roles[_role].check(_operator);
      }
    
      function hasRole(address _operator, uint8 _role)
      public
      view
      returns (bool)
      {
        return roles[_role].has(_operator);
      }
    
    }
    
    // File: openzeppelin-solidity/contracts/ownership/Ownable.sol
    
    /**
     * @title Ownable
     * @dev The Ownable contract has an owner address, and provides basic authorization control
     * functions, this simplifies the implementation of "user permissions".
     */
    contract Ownable {
      address public owner;
    
    
      event OwnershipRenounced(address indexed previousOwner);
      event OwnershipTransferred(
        address indexed previousOwner,
        address indexed newOwner
      );
    
    
      /**
       * @dev The Ownable constructor sets the original `owner` of the contract to the sender
       * account.
       */
      constructor() public {
        owner = msg.sender;
      }
    
      /**
       * @dev Throws if called by any account other than the owner.
       */
      modifier onlyOwner() {
        require(msg.sender == owner);
        _;
      }
    
      /**
       * @dev Allows the current owner to relinquish control of the contract.
       * @notice Renouncing to ownership will leave the contract without an owner.
       * It will not be possible to call the functions with the `onlyOwner`
       * modifier anymore.
       */
      function renounceOwnership() public onlyOwner {
        emit OwnershipRenounced(owner);
        owner = address(0);
      }
    
      /**
       * @dev Allows the current owner to transfer control of the contract to a newOwner.
       * @param _newOwner The address to transfer ownership to.
       */
      function transferOwnership(address _newOwner) public onlyOwner {
        _transferOwnership(_newOwner);
      }
    
      /**
       * @dev Transfers control of the contract to a newOwner.
       * @param _newOwner The address to transfer ownership to.
       */
      function _transferOwnership(address _newOwner) internal {
        require(_newOwner != address(0));
        emit OwnershipTransferred(owner, _newOwner);
        owner = _newOwner;
      }
    }
    
    // File: openzeppelin-solidity/contracts/ownership/HasNoEther.sol
    
    /**
     * @title Contracts that should not own Ether
     * @author Remco Bloemen <remco@2π.com>
     * @dev This tries to block incoming ether to prevent accidental loss of Ether. Should Ether end up
     * in the contract, it will allow the owner to reclaim this Ether.
     * @notice Ether can still be sent to this contract by:
     * calling functions labeled `payable`
     * `selfdestruct(contract_address)`
     * mining directly to the contract address
     */
    contract HasNoEther is Ownable {
    
      /**
      * @dev Constructor that rejects incoming Ether
      * The `payable` flag is added so we can access `msg.value` without compiler warning. If we
      * leave out payable, then Solidity will allow inheriting contracts to implement a payable
      * constructor. By doing it this way we prevent a payable constructor from working. Alternatively
      * we could use assembly to access msg.value.
      */
      constructor() public payable {
        require(msg.value == 0);
      }
    
      /**
       * @dev Disallows direct send by setting a default function without the `payable` flag.
       */
      function() external {
      }
    
      /**
       * @dev Transfer all Ether held by the contract to the owner.
       */
      function reclaimEther() external onlyOwner {
        owner.transfer(address(this).balance);
      }
    }
    
    // File: openzeppelin-solidity/contracts/math/SafeMath.sol
    
    /**
     * @title SafeMath
     * @dev Math operations with safety checks that throw on error
     */
    library SafeMath {
    
      /**
      * @dev Multiplies two numbers, throws on overflow.
      */
      function mul(uint256 _a, uint256 _b) internal pure returns (uint256 c) {
        // Gas optimization: this is cheaper than asserting 'a' not being zero, but the
        // benefit is lost if 'b' is also tested.
        // See: https://github.com/OpenZeppelin/openzeppelin-solidity/pull/522
        if (_a == 0) {
          return 0;
        }
    
        c = _a * _b;
        assert(c / _a == _b);
        return c;
      }
    
      /**
      * @dev Integer division of two numbers, truncating the quotient.
      */
      function div(uint256 _a, uint256 _b) internal pure returns (uint256) {
        // assert(_b > 0); // Solidity automatically throws when dividing by 0
        // uint256 c = _a / _b;
        // assert(_a == _b * c + _a % _b); // There is no case in which this doesn't hold
        return _a / _b;
      }
    
      /**
      * @dev Subtracts two numbers, throws on overflow (i.e. if subtrahend is greater than minuend).
      */
      function sub(uint256 _a, uint256 _b) internal pure returns (uint256) {
        assert(_b <= _a);
        return _a - _b;
      }
    
      /**
      * @dev Adds two numbers, throws on overflow.
      */
      function add(uint256 _a, uint256 _b) internal pure returns (uint256 c) {
        c = _a + _b;
        assert(c >= _a);
        return c;
      }
    }
    
    // File: openzeppelin-solidity/contracts/lifecycle/Pausable.sol
    
    /**
     * @title Pausable
     * @dev Base contract which allows children to implement an emergency stop mechanism.
     */
    contract Pausable is Ownable {
      event Pause();
      event Unpause();
    
      bool public paused = false;
    
    
      /**
       * @dev Modifier to make a function callable only when the contract is not paused.
       */
      modifier whenNotPaused() {
        require(!paused);
        _;
      }
    
      /**
       * @dev Modifier to make a function callable only when the contract is paused.
       */
      modifier whenPaused() {
        require(paused);
        _;
      }
    
      /**
       * @dev called by the owner to pause, triggers stopped state
       */
      function pause() public onlyOwner whenNotPaused {
        paused = true;
        emit Pause();
      }
    
      /**
       * @dev called by the owner to unpause, returns to normal state
       */
      function unpause() public onlyOwner whenPaused {
        paused = false;
        emit Unpause();
      }
    }
    
    // File: openzeppelin-solidity/contracts/introspection/ERC165.sol
    
    /**
     * @title ERC165
     * @dev https://github.com/ethereum/EIPs/blob/master/EIPS/eip-165.md
     */
    interface ERC165 {
    
      /**
       * @notice Query if a contract implements an interface
       * @param _interfaceId The interface identifier, as specified in ERC-165
       * @dev Interface identification is specified in ERC-165. This function
       * uses less than 30,000 gas.
       */
      function supportsInterface(bytes4 _interfaceId)
        external
        view
        returns (bool);
    }
    
    // File: openzeppelin-solidity/contracts/token/ERC721/ERC721Basic.sol
    
    /**
     * @title ERC721 Non-Fungible Token Standard basic interface
     * @dev see https://github.com/ethereum/EIPs/blob/master/EIPS/eip-721.md
     */
    contract ERC721Basic is ERC165 {
    
      bytes4 internal constant InterfaceId_ERC721 = 0x80ac58cd;
      /*
       * 0x80ac58cd ===
       *   bytes4(keccak256('balanceOf(address)')) ^
       *   bytes4(keccak256('ownerOf(uint256)')) ^
       *   bytes4(keccak256('approve(address,uint256)')) ^
       *   bytes4(keccak256('getApproved(uint256)')) ^
       *   bytes4(keccak256('setApprovalForAll(address,bool)')) ^
       *   bytes4(keccak256('isApprovedForAll(address,address)')) ^
       *   bytes4(keccak256('transferFrom(address,address,uint256)')) ^
       *   bytes4(keccak256('safeTransferFrom(address,address,uint256)')) ^
       *   bytes4(keccak256('safeTransferFrom(address,address,uint256,bytes)'))
       */
    
      bytes4 internal constant InterfaceId_ERC721Exists = 0x4f558e79;
      /*
       * 0x4f558e79 ===
       *   bytes4(keccak256('exists(uint256)'))
       */
    
      bytes4 internal constant InterfaceId_ERC721Enumerable = 0x780e9d63;
      /**
       * 0x780e9d63 ===
       *   bytes4(keccak256('totalSupply()')) ^
       *   bytes4(keccak256('tokenOfOwnerByIndex(address,uint256)')) ^
       *   bytes4(keccak256('tokenByIndex(uint256)'))
       */
    
      bytes4 internal constant InterfaceId_ERC721Metadata = 0x5b5e139f;
      /**
       * 0x5b5e139f ===
       *   bytes4(keccak256('name()')) ^
       *   bytes4(keccak256('symbol()')) ^
       *   bytes4(keccak256('tokenURI(uint256)'))
       */
    
      event Transfer(
        address indexed _from,
        address indexed _to,
        uint256 indexed _tokenId
      );
      event Approval(
        address indexed _owner,
        address indexed _approved,
        uint256 indexed _tokenId
      );
      event ApprovalForAll(
        address indexed _owner,
        address indexed _operator,
        bool _approved
      );
    
      function balanceOf(address _owner) public view returns (uint256 _balance);
      function ownerOf(uint256 _tokenId) public view returns (address _owner);
      function exists(uint256 _tokenId) public view returns (bool _exists);
    
      function approve(address _to, uint256 _tokenId) public;
      function getApproved(uint256 _tokenId)
        public view returns (address _operator);
    
      function setApprovalForAll(address _operator, bool _approved) public;
      function isApprovedForAll(address _owner, address _operator)
        public view returns (bool);
    
      function transferFrom(address _from, address _to, uint256 _tokenId) public;
      function safeTransferFrom(address _from, address _to, uint256 _tokenId)
        public;
    
      function safeTransferFrom(
        address _from,
        address _to,
        uint256 _tokenId,
        bytes _data
      )
        public;
    }
    
    // File: openzeppelin-solidity/contracts/token/ERC721/ERC721.sol
    
    /**
     * @title ERC-721 Non-Fungible Token Standard, optional enumeration extension
     * @dev See https://github.com/ethereum/EIPs/blob/master/EIPS/eip-721.md
     */
    contract ERC721Enumerable is ERC721Basic {
      function totalSupply() public view returns (uint256);
      function tokenOfOwnerByIndex(
        address _owner,
        uint256 _index
      )
        public
        view
        returns (uint256 _tokenId);
    
      function tokenByIndex(uint256 _index) public view returns (uint256);
    }
    
    
    /**
     * @title ERC-721 Non-Fungible Token Standard, optional metadata extension
     * @dev See https://github.com/ethereum/EIPs/blob/master/EIPS/eip-721.md
     */
    contract ERC721Metadata is ERC721Basic {
      function name() external view returns (string _name);
      function symbol() external view returns (string _symbol);
      function tokenURI(uint256 _tokenId) public view returns (string);
    }
    
    
    /**
     * @title ERC-721 Non-Fungible Token Standard, full implementation interface
     * @dev See https://github.com/ethereum/EIPs/blob/master/EIPS/eip-721.md
     */
    contract ERC721 is ERC721Basic, ERC721Enumerable, ERC721Metadata {
    }
    
    // File: openzeppelin-solidity/contracts/token/ERC721/ERC721Receiver.sol
    
    /**
     * @title ERC721 token receiver interface
     * @dev Interface for any contract that wants to support safeTransfers
     * from ERC721 asset contracts.
     */
    contract ERC721Receiver {
      /**
       * @dev Magic value to be returned upon successful reception of an NFT
       *  Equals to `bytes4(keccak256("onERC721Received(address,address,uint256,bytes)"))`,
       *  which can be also obtained as `ERC721Receiver(0).onERC721Received.selector`
       */
      bytes4 internal constant ERC721_RECEIVED = 0x150b7a02;
    
      /**
       * @notice Handle the receipt of an NFT
       * @dev The ERC721 smart contract calls this function on the recipient
       * after a `safetransfer`. This function MAY throw to revert and reject the
       * transfer. Return of other than the magic value MUST result in the
       * transaction being reverted.
       * Note: the contract address is always the message sender.
       * @param _operator The address which called `safeTransferFrom` function
       * @param _from The address which previously owned the token
       * @param _tokenId The NFT identifier which is being transferred
       * @param _data Additional data with no specified format
       * @return `bytes4(keccak256("onERC721Received(address,address,uint256,bytes)"))`
       */
      function onERC721Received(
        address _operator,
        address _from,
        uint256 _tokenId,
        bytes _data
      )
        public
        returns(bytes4);
    }
    
    // File: openzeppelin-solidity/contracts/AddressUtils.sol
    
    /**
     * Utility library of inline functions on addresses
     */
    library AddressUtils {
    
      /**
       * Returns whether the target address is a contract
       * @dev This function will return false if invoked during the constructor of a contract,
       * as the code is not actually created until after the constructor finishes.
       * @param _addr address to check
       * @return whether the target address is a contract
       */
      function isContract(address _addr) internal view returns (bool) {
        uint256 size;
        // XXX Currently there is no better way to check if there is a contract in an address
        // than to check the size of the code at that address.
        // See https://ethereum.stackexchange.com/a/14016/36603
        // for more details about how this works.
        // TODO Check this again before the Serenity release, because all addresses will be
        // contracts then.
        // solium-disable-next-line security/no-inline-assembly
        assembly { size := extcodesize(_addr) }
        return size > 0;
      }
    
    }
    
    // File: openzeppelin-solidity/contracts/introspection/SupportsInterfaceWithLookup.sol
    
    /**
     * @title SupportsInterfaceWithLookup
     * @author Matt Condon (@shrugs)
     * @dev Implements ERC165 using a lookup table.
     */
    contract SupportsInterfaceWithLookup is ERC165 {
    
      bytes4 public constant InterfaceId_ERC165 = 0x01ffc9a7;
      /**
       * 0x01ffc9a7 ===
       *   bytes4(keccak256('supportsInterface(bytes4)'))
       */
    
      /**
       * @dev a mapping of interface id to whether or not it's supported
       */
      mapping(bytes4 => bool) internal supportedInterfaces;
    
      /**
       * @dev A contract implementing SupportsInterfaceWithLookup
       * implement ERC165 itself
       */
      constructor()
        public
      {
        _registerInterface(InterfaceId_ERC165);
      }
    
      /**
       * @dev implement supportsInterface(bytes4) using a lookup table
       */
      function supportsInterface(bytes4 _interfaceId)
        external
        view
        returns (bool)
      {
        return supportedInterfaces[_interfaceId];
      }
    
      /**
       * @dev private method for registering an interface
       */
      function _registerInterface(bytes4 _interfaceId)
        internal
      {
        require(_interfaceId != 0xffffffff);
        supportedInterfaces[_interfaceId] = true;
      }
    }
    
    // File: openzeppelin-solidity/contracts/token/ERC721/ERC721BasicToken.sol
    
    /**
     * @title ERC721 Non-Fungible Token Standard basic implementation
     * @dev see https://github.com/ethereum/EIPs/blob/master/EIPS/eip-721.md
     */
    contract ERC721BasicToken is SupportsInterfaceWithLookup, ERC721Basic {
    
      using SafeMath for uint256;
      using AddressUtils for address;
    
      // Equals to `bytes4(keccak256("onERC721Received(address,address,uint256,bytes)"))`
      // which can be also obtained as `ERC721Receiver(0).onERC721Received.selector`
      bytes4 private constant ERC721_RECEIVED = 0x150b7a02;
    
      // Mapping from token ID to owner
      mapping (uint256 => address) internal tokenOwner;
    
      // Mapping from token ID to approved address
      mapping (uint256 => address) internal tokenApprovals;
    
      // Mapping from owner to number of owned token
      mapping (address => uint256) internal ownedTokensCount;
    
      // Mapping from owner to operator approvals
      mapping (address => mapping (address => bool)) internal operatorApprovals;
    
      constructor()
        public
      {
        // register the supported interfaces to conform to ERC721 via ERC165
        _registerInterface(InterfaceId_ERC721);
        _registerInterface(InterfaceId_ERC721Exists);
      }
    
      /**
       * @dev Gets the balance of the specified address
       * @param _owner address to query the balance of
       * @return uint256 representing the amount owned by the passed address
       */
      function balanceOf(address _owner) public view returns (uint256) {
        require(_owner != address(0));
        return ownedTokensCount[_owner];
      }
    
      /**
       * @dev Gets the owner of the specified token ID
       * @param _tokenId uint256 ID of the token to query the owner of
       * @return owner address currently marked as the owner of the given token ID
       */
      function ownerOf(uint256 _tokenId) public view returns (address) {
        address owner = tokenOwner[_tokenId];
        require(owner != address(0));
        return owner;
      }
    
      /**
       * @dev Returns whether the specified token exists
       * @param _tokenId uint256 ID of the token to query the existence of
       * @return whether the token exists
       */
      function exists(uint256 _tokenId) public view returns (bool) {
        address owner = tokenOwner[_tokenId];
        return owner != address(0);
      }
    
      /**
       * @dev Approves another address to transfer the given token ID
       * The zero address indicates there is no approved address.
       * There can only be one approved address per token at a given time.
       * Can only be called by the token owner or an approved operator.
       * @param _to address to be approved for the given token ID
       * @param _tokenId uint256 ID of the token to be approved
       */
      function approve(address _to, uint256 _tokenId) public {
        address owner = ownerOf(_tokenId);
        require(_to != owner);
        require(msg.sender == owner || isApprovedForAll(owner, msg.sender));
    
        tokenApprovals[_tokenId] = _to;
        emit Approval(owner, _to, _tokenId);
      }
    
      /**
       * @dev Gets the approved address for a token ID, or zero if no address set
       * @param _tokenId uint256 ID of the token to query the approval of
       * @return address currently approved for the given token ID
       */
      function getApproved(uint256 _tokenId) public view returns (address) {
        return tokenApprovals[_tokenId];
      }
    
      /**
       * @dev Sets or unsets the approval of a given operator
       * An operator is allowed to transfer all tokens of the sender on their behalf
       * @param _to operator address to set the approval
       * @param _approved representing the status of the approval to be set
       */
      function setApprovalForAll(address _to, bool _approved) public {
        require(_to != msg.sender);
        operatorApprovals[msg.sender][_to] = _approved;
        emit ApprovalForAll(msg.sender, _to, _approved);
      }
    
      /**
       * @dev Tells whether an operator is approved by a given owner
       * @param _owner owner address which you want to query the approval of
       * @param _operator operator address which you want to query the approval of
       * @return bool whether the given operator is approved by the given owner
       */
      function isApprovedForAll(
        address _owner,
        address _operator
      )
        public
        view
        returns (bool)
      {
        return operatorApprovals[_owner][_operator];
      }
    
      /**
       * @dev Transfers the ownership of a given token ID to another address
       * Usage of this method is discouraged, use `safeTransferFrom` whenever possible
       * Requires the msg sender to be the owner, approved, or operator
       * @param _from current owner of the token
       * @param _to address to receive the ownership of the given token ID
       * @param _tokenId uint256 ID of the token to be transferred
      */
      function transferFrom(
        address _from,
        address _to,
        uint256 _tokenId
      )
        public
      {
        require(isApprovedOrOwner(msg.sender, _tokenId));
        require(_from != address(0));
        require(_to != address(0));
    
        clearApproval(_from, _tokenId);
        removeTokenFrom(_from, _tokenId);
        addTokenTo(_to, _tokenId);
    
        emit Transfer(_from, _to, _tokenId);
      }
    
      /**
       * @dev Safely transfers the ownership of a given token ID to another address
       * If the target address is a contract, it must implement `onERC721Received`,
       * which is called upon a safe transfer, and return the magic value
       * `bytes4(keccak256("onERC721Received(address,address,uint256,bytes)"))`; otherwise,
       * the transfer is reverted.
       *
       * Requires the msg sender to be the owner, approved, or operator
       * @param _from current owner of the token
       * @param _to address to receive the ownership of the given token ID
       * @param _tokenId uint256 ID of the token to be transferred
      */
      function safeTransferFrom(
        address _from,
        address _to,
        uint256 _tokenId
      )
        public
      {
        // solium-disable-next-line arg-overflow
        safeTransferFrom(_from, _to, _tokenId, "");
      }
    
      /**
       * @dev Safely transfers the ownership of a given token ID to another address
       * If the target address is a contract, it must implement `onERC721Received`,
       * which is called upon a safe transfer, and return the magic value
       * `bytes4(keccak256("onERC721Received(address,address,uint256,bytes)"))`; otherwise,
       * the transfer is reverted.
       * Requires the msg sender to be the owner, approved, or operator
       * @param _from current owner of the token
       * @param _to address to receive the ownership of the given token ID
       * @param _tokenId uint256 ID of the token to be transferred
       * @param _data bytes data to send along with a safe transfer check
       */
      function safeTransferFrom(
        address _from,
        address _to,
        uint256 _tokenId,
        bytes _data
      )
        public
      {
        transferFrom(_from, _to, _tokenId);
        // solium-disable-next-line arg-overflow
        require(checkAndCallSafeTransfer(_from, _to, _tokenId, _data));
      }
    
      /**
       * @dev Returns whether the given spender can transfer a given token ID
       * @param _spender address of the spender to query
       * @param _tokenId uint256 ID of the token to be transferred
       * @return bool whether the msg.sender is approved for the given token ID,
       *  is an operator of the owner, or is the owner of the token
       */
      function isApprovedOrOwner(
        address _spender,
        uint256 _tokenId
      )
        internal
        view
        returns (bool)
      {
        address owner = ownerOf(_tokenId);
        // Disable solium check because of
        // https://github.com/duaraghav8/Solium/issues/175
        // solium-disable-next-line operator-whitespace
        return (
          _spender == owner ||
          getApproved(_tokenId) == _spender ||
          isApprovedForAll(owner, _spender)
        );
      }
    
      /**
       * @dev Internal function to mint a new token
       * Reverts if the given token ID already exists
       * @param _to The address that will own the minted token
       * @param _tokenId uint256 ID of the token to be minted by the msg.sender
       */
      function _mint(address _to, uint256 _tokenId) internal {
        require(_to != address(0));
        addTokenTo(_to, _tokenId);
        emit Transfer(address(0), _to, _tokenId);
      }
    
      /**
       * @dev Internal function to burn a specific token
       * Reverts if the token does not exist
       * @param _tokenId uint256 ID of the token being burned by the msg.sender
       */
      function _burn(address _owner, uint256 _tokenId) internal {
        clearApproval(_owner, _tokenId);
        removeTokenFrom(_owner, _tokenId);
        emit Transfer(_owner, address(0), _tokenId);
      }
    
      /**
       * @dev Internal function to clear current approval of a given token ID
       * Reverts if the given address is not indeed the owner of the token
       * @param _owner owner of the token
       * @param _tokenId uint256 ID of the token to be transferred
       */
      function clearApproval(address _owner, uint256 _tokenId) internal {
        require(ownerOf(_tokenId) == _owner);
        if (tokenApprovals[_tokenId] != address(0)) {
          tokenApprovals[_tokenId] = address(0);
        }
      }
    
      /**
       * @dev Internal function to add a token ID to the list of a given address
       * @param _to address representing the new owner of the given token ID
       * @param _tokenId uint256 ID of the token to be added to the tokens list of the given address
       */
      function addTokenTo(address _to, uint256 _tokenId) internal {
        require(tokenOwner[_tokenId] == address(0));
        tokenOwner[_tokenId] = _to;
        ownedTokensCount[_to] = ownedTokensCount[_to].add(1);
      }
    
      /**
       * @dev Internal function to remove a token ID from the list of a given address
       * @param _from address representing the previous owner of the given token ID
       * @param _tokenId uint256 ID of the token to be removed from the tokens list of the given address
       */
      function removeTokenFrom(address _from, uint256 _tokenId) internal {
        require(ownerOf(_tokenId) == _from);
        ownedTokensCount[_from] = ownedTokensCount[_from].sub(1);
        tokenOwner[_tokenId] = address(0);
      }
    
      /**
       * @dev Internal function to invoke `onERC721Received` on a target address
       * The call is not executed if the target address is not a contract
       * @param _from address representing the previous owner of the given token ID
       * @param _to target address that will receive the tokens
       * @param _tokenId uint256 ID of the token to be transferred
       * @param _data bytes optional data to send along with the call
       * @return whether the call correctly returned the expected magic value
       */
      function checkAndCallSafeTransfer(
        address _from,
        address _to,
        uint256 _tokenId,
        bytes _data
      )
        internal
        returns (bool)
      {
        if (!_to.isContract()) {
          return true;
        }
        bytes4 retval = ERC721Receiver(_to).onERC721Received(
          msg.sender, _from, _tokenId, _data);
        return (retval == ERC721_RECEIVED);
      }
    }
    
    // File: openzeppelin-solidity/contracts/token/ERC721/ERC721Token.sol
    
    /**
     * @title Full ERC721 Token
     * This implementation includes all the required and some optional functionality of the ERC721 standard
     * Moreover, it includes approve all functionality using operator terminology
     * @dev see https://github.com/ethereum/EIPs/blob/master/EIPS/eip-721.md
     */
    contract ERC721Token is SupportsInterfaceWithLookup, ERC721BasicToken, ERC721 {
    
      // Token name
      string internal name_;
    
      // Token symbol
      string internal symbol_;
    
      // Mapping from owner to list of owned token IDs
      mapping(address => uint256[]) internal ownedTokens;
    
      // Mapping from token ID to index of the owner tokens list
      mapping(uint256 => uint256) internal ownedTokensIndex;
    
      // Array with all token ids, used for enumeration
      uint256[] internal allTokens;
    
      // Mapping from token id to position in the allTokens array
      mapping(uint256 => uint256) internal allTokensIndex;
    
      // Optional mapping for token URIs
      mapping(uint256 => string) internal tokenURIs;
    
      /**
       * @dev Constructor function
       */
      constructor(string _name, string _symbol) public {
        name_ = _name;
        symbol_ = _symbol;
    
        // register the supported interfaces to conform to ERC721 via ERC165
        _registerInterface(InterfaceId_ERC721Enumerable);
        _registerInterface(InterfaceId_ERC721Metadata);
      }
    
      /**
       * @dev Gets the token name
       * @return string representing the token name
       */
      function name() external view returns (string) {
        return name_;
      }
    
      /**
       * @dev Gets the token symbol
       * @return string representing the token symbol
       */
      function symbol() external view returns (string) {
        return symbol_;
      }
    
      /**
       * @dev Returns an URI for a given token ID
       * Throws if the token ID does not exist. May return an empty string.
       * @param _tokenId uint256 ID of the token to query
       */
      function tokenURI(uint256 _tokenId) public view returns (string) {
        require(exists(_tokenId));
        return tokenURIs[_tokenId];
      }
    
      /**
       * @dev Gets the token ID at a given index of the tokens list of the requested owner
       * @param _owner address owning the tokens list to be accessed
       * @param _index uint256 representing the index to be accessed of the requested tokens list
       * @return uint256 token ID at the given index of the tokens list owned by the requested address
       */
      function tokenOfOwnerByIndex(
        address _owner,
        uint256 _index
      )
        public
        view
        returns (uint256)
      {
        require(_index < balanceOf(_owner));
        return ownedTokens[_owner][_index];
      }
    
      /**
       * @dev Gets the total amount of tokens stored by the contract
       * @return uint256 representing the total amount of tokens
       */
      function totalSupply() public view returns (uint256) {
        return allTokens.length;
      }
    
      /**
       * @dev Gets the token ID at a given index of all the tokens in this contract
       * Reverts if the index is greater or equal to the total number of tokens
       * @param _index uint256 representing the index to be accessed of the tokens list
       * @return uint256 token ID at the given index of the tokens list
       */
      function tokenByIndex(uint256 _index) public view returns (uint256) {
        require(_index < totalSupply());
        return allTokens[_index];
      }
    
      /**
       * @dev Internal function to set the token URI for a given token
       * Reverts if the token ID does not exist
       * @param _tokenId uint256 ID of the token to set its URI
       * @param _uri string URI to assign
       */
      function _setTokenURI(uint256 _tokenId, string _uri) internal {
        require(exists(_tokenId));
        tokenURIs[_tokenId] = _uri;
      }
    
      /**
       * @dev Internal function to add a token ID to the list of a given address
       * @param _to address representing the new owner of the given token ID
       * @param _tokenId uint256 ID of the token to be added to the tokens list of the given address
       */
      function addTokenTo(address _to, uint256 _tokenId) internal {
        super.addTokenTo(_to, _tokenId);
        uint256 length = ownedTokens[_to].length;
        ownedTokens[_to].push(_tokenId);
        ownedTokensIndex[_tokenId] = length;
      }
    
      /**
       * @dev Internal function to remove a token ID from the list of a given address
       * @param _from address representing the previous owner of the given token ID
       * @param _tokenId uint256 ID of the token to be removed from the tokens list of the given address
       */
      function removeTokenFrom(address _from, uint256 _tokenId) internal {
        super.removeTokenFrom(_from, _tokenId);
    
        // To prevent a gap in the array, we store the last token in the index of the token to delete, and
        // then delete the last slot.
        uint256 tokenIndex = ownedTokensIndex[_tokenId];
        uint256 lastTokenIndex = ownedTokens[_from].length.sub(1);
        uint256 lastToken = ownedTokens[_from][lastTokenIndex];
    
        ownedTokens[_from][tokenIndex] = lastToken;
        // This also deletes the contents at the last position of the array
        ownedTokens[_from].length--;
    
        // Note that this will handle single-element arrays. In that case, both tokenIndex and lastTokenIndex are going to
        // be zero. Then we can make sure that we will remove _tokenId from the ownedTokens list since we are first swapping
        // the lastToken to the first position, and then dropping the element placed in the last position of the list
    
        ownedTokensIndex[_tokenId] = 0;
        ownedTokensIndex[lastToken] = tokenIndex;
      }
    
      /**
       * @dev Internal function to mint a new token
       * Reverts if the given token ID already exists
       * @param _to address the beneficiary that will own the minted token
       * @param _tokenId uint256 ID of the token to be minted by the msg.sender
       */
      function _mint(address _to, uint256 _tokenId) internal {
        super._mint(_to, _tokenId);
    
        allTokensIndex[_tokenId] = allTokens.length;
        allTokens.push(_tokenId);
      }
    
      /**
       * @dev Internal function to burn a specific token
       * Reverts if the token does not exist
       * @param _owner owner of the token to burn
       * @param _tokenId uint256 ID of the token being burned by the msg.sender
       */
      function _burn(address _owner, uint256 _tokenId) internal {
        super._burn(_owner, _tokenId);
    
        // Clear metadata (if any)
        if (bytes(tokenURIs[_tokenId]).length != 0) {
          delete tokenURIs[_tokenId];
        }
    
        // Reorg all tokens array
        uint256 tokenIndex = allTokensIndex[_tokenId];
        uint256 lastTokenIndex = allTokens.length.sub(1);
        uint256 lastToken = allTokens[lastTokenIndex];
    
        allTokens[tokenIndex] = lastToken;
        allTokens[lastTokenIndex] = 0;
    
        allTokens.length--;
        allTokensIndex[_tokenId] = 0;
        allTokensIndex[lastToken] = tokenIndex;
      }
    
    }
    
    // File: contracts/v2/Strings.sol
    
    library Strings {
      // via https://github.com/oraclize/ethereum-api/blob/master/oraclizeAPI_0.5.sol
      function strConcat(string _a, string _b, string _c, string _d, string _e) internal pure returns (string) {
        bytes memory _ba = bytes(_a);
        bytes memory _bb = bytes(_b);
        bytes memory _bc = bytes(_c);
        bytes memory _bd = bytes(_d);
        bytes memory _be = bytes(_e);
        string memory abcde = new string(_ba.length + _bb.length + _bc.length + _bd.length + _be.length);
        bytes memory babcde = bytes(abcde);
        uint k = 0;
        for (uint i = 0; i < _ba.length; i++) babcde[k++] = _ba[i];
        for (i = 0; i < _bb.length; i++) babcde[k++] = _bb[i];
        for (i = 0; i < _bc.length; i++) babcde[k++] = _bc[i];
        for (i = 0; i < _bd.length; i++) babcde[k++] = _bd[i];
        for (i = 0; i < _be.length; i++) babcde[k++] = _be[i];
        return string(babcde);
      }
    
      function strConcat(string _a, string _b) internal pure returns (string) {
        return strConcat(_a, _b, "", "", "");
      }
    }
    
    // File: contracts/v2/KnownOriginDigitalAssetV2.sol
    
    // allows for multi-address access controls to different functions
    
    
    // Prevents stuck ether
    
    
    // For safe maths operations
    
    
    // Pause purchasing only in case of emergency/migration
    
    
    // ERC721
    
    
    // Utils only
    
    
    /**
    * @title KnownOriginDigitalAsset - V2
    *
    * http://www.knownorigin.io/
    *
    * ERC721 compliant digital assets for real-world artwork.
    *
    * Base NFT Issuance Contract
    *
    * BE ORIGINAL. BUY ORIGINAL.
    *
    */
    contract KnownOriginDigitalAssetV2 is
    ERC721Token,
    AccessControl,
    HasNoEther,
    Pausable
    {
      using SafeMath for uint256;
    
      ////////////
      // Events //
      ////////////
    
      // Emitted on purchases from within this contract
      event Purchase(
        uint256 indexed _tokenId,
        uint256 indexed _editionNumber,
        address indexed _buyer,
        uint256 _priceInWei
      );
    
      // Emitted on every mint
      event Minted(
        uint256 indexed _tokenId,
        uint256 indexed _editionNumber,
        address indexed _buyer
      );
    
      // Emitted on every edition created
      event EditionCreated(
        uint256 indexed _editionNumber,
        bytes32 indexed _editionData,
        uint256 indexed _editionType
      );
    
      ////////////////
      // Properties //
      ////////////////
    
      uint256 constant internal MAX_UINT32 = ~uint32(0);
    
      string public tokenBaseURI = "https://ipfs.infura.io/ipfs/";
    
      // simple counter to keep track of the highest edition number used
      uint256 public highestEditionNumber;
    
      // total wei been processed through the contract
      uint256 public totalPurchaseValueInWei;
    
      // number of assets minted of any type
      uint256 public totalNumberMinted;
    
      // number of assets available of any type
      uint256 public totalNumberAvailable;
    
      // the KO account which can receive commission
      address public koCommissionAccount;
    
      // Optional commission split can be defined per edition
      mapping(uint256 => CommissionSplit) editionNumberToOptionalCommissionSplit;
    
      // Simple structure providing an optional commission split per edition purchase
      struct CommissionSplit {
        uint256 rate;
        address recipient;
      }
    
      // Object for edition details
      struct EditionDetails {
        // Identifiers
        uint256 editionNumber;    // the range e.g. 10000
        bytes32 editionData;      // some data about the edition
        uint256 editionType;      // e.g. 1 = KODA V1, 2 = KOTA, 3 = Bespoke partnership
        // Config
        uint256 startDate;        // date when the edition goes on sale
        uint256 endDate;          // date when the edition is available until
        address artistAccount;    // artists account
        uint256 artistCommission; // base artists commission, could be overridden by external contracts
        uint256 priceInWei;       // base price for edition, could be overridden by external contracts
        string tokenURI;          // IPFS hash - see base URI
        bool active;              // Root control - on/off for the edition
        // Counters
        uint256 totalSupply;      // Total purchases or mints
        uint256 totalAvailable;   // Total number available to be purchased
      }
    
      // _editionNumber : EditionDetails
      mapping(uint256 => EditionDetails) internal editionNumberToEditionDetails;
    
      // _tokenId : _editionNumber
      mapping(uint256 => uint256) internal tokenIdToEditionNumber;
    
      // _editionNumber : [_tokenId, _tokenId]
      mapping(uint256 => uint256[]) internal editionNumberToTokenIds;
      mapping(uint256 => uint256) internal editionNumberToTokenIdIndex;
    
      // _artistAccount : [_editionNumber, _editionNumber]
      mapping(address => uint256[]) internal artistToEditionNumbers;
      mapping(uint256 => uint256) internal editionNumberToArtistIndex;
    
      // _editionType : [_editionNumber, _editionNumber]
      mapping(uint256 => uint256[]) internal editionTypeToEditionNumber;
      mapping(uint256 => uint256) internal editionNumberToTypeIndex;
    
      ///////////////
      // Modifiers //
      ///////////////
    
      modifier onlyAvailableEdition(uint256 _editionNumber) {
        require(editionNumberToEditionDetails[_editionNumber].totalSupply < editionNumberToEditionDetails[_editionNumber].totalAvailable, "No more editions left to purchase");
        _;
      }
    
      modifier onlyActiveEdition(uint256 _editionNumber) {
        require(editionNumberToEditionDetails[_editionNumber].active, "Edition not active");
        _;
      }
    
      modifier onlyRealEdition(uint256 _editionNumber) {
        require(editionNumberToEditionDetails[_editionNumber].editionNumber > 0, "Edition number invalid");
        _;
      }
    
      modifier onlyValidTokenId(uint256 _tokenId) {
        require(exists(_tokenId), "Token ID does not exist");
        _;
      }
    
      modifier onlyPurchaseDuringWindow(uint256 _editionNumber) {
        require(editionNumberToEditionDetails[_editionNumber].startDate <= block.timestamp, "Edition not available yet");
        require(editionNumberToEditionDetails[_editionNumber].endDate >= block.timestamp, "Edition no longer available");
        _;
      }
    
      /*
       * Constructor
       */
      constructor () public payable ERC721Token("KnownOriginDigitalAsset", "KODA") {
        // set commission account to contract creator
        koCommissionAccount = msg.sender;
      }
    
      /**
       * @dev Creates an active edition from the given configuration
       * @dev Only callable from KO staff/addresses
       */
      function createActiveEdition(
        uint256 _editionNumber,
        bytes32 _editionData,
        uint256 _editionType,
        uint256 _startDate,
        uint256 _endDate,
        address _artistAccount,
        uint256 _artistCommission,
        uint256 _priceInWei,
        string _tokenURI,
        uint256 _totalAvailable
      )
      public
      onlyIfKnownOrigin
      returns (bool)
      {
        return _createEdition(_editionNumber, _editionData, _editionType, _startDate, _endDate, _artistAccount, _artistCommission, _priceInWei, _tokenURI, _totalAvailable, true);
      }
    
      /**
       * @dev Creates an inactive edition from the given configuration
       * @dev Only callable from KO staff/addresses
       */
      function createInactiveEdition(
        uint256 _editionNumber,
        bytes32 _editionData,
        uint256 _editionType,
        uint256 _startDate,
        uint256 _endDate,
        address _artistAccount,
        uint256 _artistCommission,
        uint256 _priceInWei,
        string _tokenURI,
        uint256 _totalAvailable
      )
      public
      onlyIfKnownOrigin
      returns (bool)
      {
        return _createEdition(_editionNumber, _editionData, _editionType, _startDate, _endDate, _artistAccount, _artistCommission, _priceInWei, _tokenURI, _totalAvailable, false);
      }
    
      /**
       * @dev Creates an active edition from the given configuration
       * @dev The concept of pre0minted editions means we can 'undermint' token IDS, good for holding back editions from public sale
       * @dev Only callable from KO staff/addresses
       */
      function createActivePreMintedEdition(
        uint256 _editionNumber,
        bytes32 _editionData,
        uint256 _editionType,
        uint256 _startDate,
        uint256 _endDate,
        address _artistAccount,
        uint256 _artistCommission,
        uint256 _priceInWei,
        string _tokenURI,
        uint256 _totalSupply,
        uint256 _totalAvailable
      )
      public
      onlyIfKnownOrigin
      returns (bool)
      {
        _createEdition(_editionNumber, _editionData, _editionType, _startDate, _endDate, _artistAccount, _artistCommission, _priceInWei, _tokenURI, _totalAvailable, true);
        updateTotalSupply(_editionNumber, _totalSupply);
        return true;
      }
    
      /**
       * @dev Creates an inactive edition from the given configuration
       * @dev The concept of pre0minted editions means we can 'undermint' token IDS, good for holding back editions from public sale
       * @dev Only callable from KO staff/addresses
       */
      function createInactivePreMintedEdition(
        uint256 _editionNumber,
        bytes32 _editionData,
        uint256 _editionType,
        uint256 _startDate,
        uint256 _endDate,
        address _artistAccount,
        uint256 _artistCommission,
        uint256 _priceInWei,
        string _tokenURI,
        uint256 _totalSupply,
        uint256 _totalAvailable
      )
      public
      onlyIfKnownOrigin
      returns (bool)
      {
        _createEdition(_editionNumber, _editionData, _editionType, _startDate, _endDate, _artistAccount, _artistCommission, _priceInWei, _tokenURI, _totalAvailable, false);
        updateTotalSupply(_editionNumber, _totalSupply);
        return true;
      }
    
      /**
       * @dev Internal factory method for building editions
       */
      function _createEdition(
        uint256 _editionNumber,
        bytes32 _editionData,
        uint256 _editionType,
        uint256 _startDate,
        uint256 _endDate,
        address _artistAccount,
        uint256 _artistCommission,
        uint256 _priceInWei,
        string _tokenURI,
        uint256 _totalAvailable,
        bool _active
      )
      internal
      returns (bool)
      {
        // Prevent missing edition number
        require(_editionNumber != 0, "Edition number not provided");
    
        // Prevent edition number lower than last one used
        require(_editionNumber > highestEditionNumber, "Edition number must be greater than previously used");
    
        // Check previously edition plus total available is less than new edition number
        require(highestEditionNumber.add(editionNumberToEditionDetails[highestEditionNumber].totalAvailable) < _editionNumber, "Edition number must be greater than previously used plus total available");
    
        // Prevent missing types
        require(_editionType != 0, "Edition type not provided");
    
        // Prevent missing token URI
        require(bytes(_tokenURI).length != 0, "Token URI is missing");
    
        // Prevent empty artists address
        require(_artistAccount != address(0), "Artist account not provided");
    
        // Prevent invalid commissions
        require(_artistCommission <= 100 && _artistCommission >= 0, "Artist commission cannot be greater than 100 or less than 0");
    
        // Prevent duplicate editions
        require(editionNumberToEditionDetails[_editionNumber].editionNumber == 0, "Edition already in existence");
    
        // Default end date to max uint256
        uint256 endDate = _endDate;
        if (_endDate == 0) {
          endDate = MAX_UINT32;
        }
    
        editionNumberToEditionDetails[_editionNumber] = EditionDetails({
          editionNumber : _editionNumber,
          editionData : _editionData,
          editionType : _editionType,
          startDate : _startDate,
          endDate : endDate,
          artistAccount : _artistAccount,
          artistCommission : _artistCommission,
          priceInWei : _priceInWei,
          tokenURI : _tokenURI,
          totalSupply : 0, // default to all available
          totalAvailable : _totalAvailable,
          active : _active
          });
    
        // Add to total available count
        totalNumberAvailable = totalNumberAvailable.add(_totalAvailable);
    
        // Update mappings
        _updateArtistLookupData(_artistAccount, _editionNumber);
        _updateEditionTypeLookupData(_editionType, _editionNumber);
    
        emit EditionCreated(_editionNumber, _editionData, _editionType);
    
        // Update the edition pointer if needs be
        highestEditionNumber = _editionNumber;
    
        return true;
      }
    
      function _updateEditionTypeLookupData(uint256 _editionType, uint256 _editionNumber) internal {
        uint256 typeEditionIndex = editionTypeToEditionNumber[_editionType].length;
        editionTypeToEditionNumber[_editionType].push(_editionNumber);
        editionNumberToTypeIndex[_editionNumber] = typeEditionIndex;
      }
    
      function _updateArtistLookupData(address _artistAccount, uint256 _editionNumber) internal {
        uint256 artistEditionIndex = artistToEditionNumbers[_artistAccount].length;
        artistToEditionNumbers[_artistAccount].push(_editionNumber);
        editionNumberToArtistIndex[_editionNumber] = artistEditionIndex;
      }
    
      /**
       * @dev Public entry point for purchasing an edition
       * @dev Reverts if edition is invalid
       * @dev Reverts if payment not provided in full
       * @dev Reverts if edition is sold out
       * @dev Reverts if edition is not active or available
       */
      function purchase(uint256 _editionNumber)
      public
      payable
      returns (uint256) {
        return purchaseTo(msg.sender, _editionNumber);
      }
    
      /**
       * @dev Public entry point for purchasing an edition on behalf of someone else
       * @dev Reverts if edition is invalid
       * @dev Reverts if payment not provided in full
       * @dev Reverts if edition is sold out
       * @dev Reverts if edition is not active or available
       */
      function purchaseTo(address _to, uint256 _editionNumber)
      public
      payable
      whenNotPaused
      onlyRealEdition(_editionNumber)
      onlyActiveEdition(_editionNumber)
      onlyAvailableEdition(_editionNumber)
      onlyPurchaseDuringWindow(_editionNumber)
      returns (uint256) {
    
        EditionDetails storage _editionDetails = editionNumberToEditionDetails[_editionNumber];
        require(msg.value >= _editionDetails.priceInWei, "Value must be greater than price of edition");
    
        // Construct next token ID e.g. 100000 + 1 = ID of 100001 (this first in the edition set)
        uint256 _tokenId = _nextTokenId(_editionNumber);
    
        // Create the token
        _mintToken(_to, _tokenId, _editionNumber, _editionDetails.tokenURI);
    
        // Splice funds and handle commissions
        _handleFunds(_editionNumber, _editionDetails.priceInWei, _editionDetails.artistAccount, _editionDetails.artistCommission);
    
        // Broadcast purchase
        emit Purchase(_tokenId, _editionNumber, _to, msg.value);
    
        return _tokenId;
      }
    
      /**
       * @dev Private (KO only) method for minting editions
       * @dev Payment not needed for this method
       */
      function mint(address _to, uint256 _editionNumber)
      public
      onlyIfMinter
      onlyRealEdition(_editionNumber)
      onlyAvailableEdition(_editionNumber)
      returns (uint256) {
        // Construct next token ID e.g. 100000 + 1 = ID of 100001 (this first in the edition set)
        uint256 _tokenId = _nextTokenId(_editionNumber);
    
        // Create the token
        _mintToken(_to, _tokenId, _editionNumber, editionNumberToEditionDetails[_editionNumber].tokenURI);
    
        // Create the token
        return _tokenId;
      }
    
      /**
       * @dev Private (KO only) method for under minting editions
       * @dev Under minting allows for token IDs to be back filled if total supply is not set to zero by default
       * @dev Payment not needed for this method
       */
      function underMint(address _to, uint256 _editionNumber)
      public
      onlyIfUnderMinter
      onlyRealEdition(_editionNumber)
      returns (uint256) {
        // Under mint token, meaning it takes one from the already sold version
        uint256 _tokenId = _underMintNextTokenId(_editionNumber);
    
        // If the next tokenId generate is more than the available number, abort as we have reached maximum under mint
        if (_tokenId > _editionNumber.add(editionNumberToEditionDetails[_editionNumber].totalAvailable)) {
          revert("Reached max tokenId, cannot under mint anymore");
        }
    
        // Create the token
        _mintToken(_to, _tokenId, _editionNumber, editionNumberToEditionDetails[_editionNumber].tokenURI);
    
        // Create the token
        return _tokenId;
      }
    
      function _nextTokenId(uint256 _editionNumber) internal returns (uint256) {
        EditionDetails storage _editionDetails = editionNumberToEditionDetails[_editionNumber];
    
        // Bump number totalSupply
        _editionDetails.totalSupply = _editionDetails.totalSupply.add(1);
    
        // Construct next token ID e.g. 100000 + 1 = ID of 100001 (this first in the edition set)
        return _editionDetails.editionNumber.add(_editionDetails.totalSupply);
      }
    
      function _underMintNextTokenId(uint256 _editionNumber) internal returns (uint256) {
        EditionDetails storage _editionDetails = editionNumberToEditionDetails[_editionNumber];
    
        // For old editions start the counter as edition + 1
        uint256 _tokenId = _editionDetails.editionNumber.add(1);
    
        // Work your way up until you find a free token based on the new _tokenIdd
        while (exists(_tokenId)) {
          _tokenId = _tokenId.add(1);
        }
    
        // Bump number totalSupply if we are now over minting new tokens
        if (_tokenId > _editionDetails.editionNumber.add(_editionDetails.totalSupply)) {
          _editionDetails.totalSupply = _editionDetails.totalSupply.add(1);
        }
    
        return _tokenId;
      }
    
      function _mintToken(address _to, uint256 _tokenId, uint256 _editionNumber, string _tokenURI) internal {
    
        // Mint new base token
        super._mint(_to, _tokenId);
        super._setTokenURI(_tokenId, _tokenURI);
    
        // Maintain mapping for tokenId to edition for lookup
        tokenIdToEditionNumber[_tokenId] = _editionNumber;
    
        // Get next insert position for edition to token Id mapping
        uint256 currentIndexOfTokenId = editionNumberToTokenIds[_editionNumber].length;
    
        // Maintain mapping of edition to token array for "edition minted tokens"
        editionNumberToTokenIds[_editionNumber].push(_tokenId);
    
        // Maintain a position index for the tokenId within the edition number mapping array, used for clean up token burn
        editionNumberToTokenIdIndex[_tokenId] = currentIndexOfTokenId;
    
        // Record sale volume
        totalNumberMinted = totalNumberMinted.add(1);
    
        // Emit minted event
        emit Minted(_tokenId, _editionNumber, _to);
      }
    
      function _handleFunds(uint256 _editionNumber, uint256 _priceInWei, address _artistAccount, uint256 _artistCommission) internal {
    
        // Extract the artists commission and send it
        uint256 artistPayment = _priceInWei.div(100).mul(_artistCommission);
        if (artistPayment > 0) {
          _artistAccount.transfer(artistPayment);
        }
    
        // Load any commission overrides
        CommissionSplit storage commission = editionNumberToOptionalCommissionSplit[_editionNumber];
    
        // Apply optional commission structure
        if (commission.rate > 0) {
          uint256 rateSplit = _priceInWei.div(100).mul(commission.rate);
          commission.recipient.transfer(rateSplit);
        }
    
        // Send remaining eth to KO
        uint256 remainingCommission = msg.value.sub(artistPayment).sub(rateSplit);
        koCommissionAccount.transfer(remainingCommission);
    
        // Record wei sale value
        totalPurchaseValueInWei = totalPurchaseValueInWei.add(msg.value);
      }
    
      /**
       * @dev Private (KO only) method for burning tokens which have been created incorrectly
       */
      function burn(uint256 _tokenId) public onlyIfKnownOrigin {
    
        // Clear from parents
        super._burn(ownerOf(_tokenId), _tokenId);
    
        // Get hold of the edition for cleanup
        uint256 _editionNumber = tokenIdToEditionNumber[_tokenId];
    
        // Delete token ID mapping
        delete tokenIdToEditionNumber[_tokenId];
    
        // Delete tokens associated to the edition - this will leave a gap in the array of zero
        uint256[] storage tokenIdsForEdition = editionNumberToTokenIds[_editionNumber];
        uint256 editionTokenIdIndex = editionNumberToTokenIdIndex[_tokenId];
        delete tokenIdsForEdition[editionTokenIdIndex];
      }
    
      /**
       * @dev An extension to the default ERC721 behaviour, derived from ERC-875.
       * @dev Allowing for batch transfers from the sender, will fail if from does not own all the tokens
       */
      function batchTransfer(address _to, uint256[] _tokenIds) public {
        for (uint i = 0; i < _tokenIds.length; i++) {
          safeTransferFrom(ownerOf(_tokenIds[i]), _to, _tokenIds[i]);
        }
      }
    
      /**
       * @dev An extension to the default ERC721 behaviour, derived from ERC-875.
       * @dev Allowing for batch transfers from the provided address, will fail if from does not own all the tokens
       */
      function batchTransferFrom(address _from, address _to, uint256[] _tokenIds) public {
        for (uint i = 0; i < _tokenIds.length; i++) {
          transferFrom(_from, _to, _tokenIds[i]);
        }
      }
    
      //////////////////
      // Base Updates //
      //////////////////
    
      function updateTokenBaseURI(string _newBaseURI)
      external
      onlyIfKnownOrigin {
        require(bytes(_newBaseURI).length != 0, "Base URI invalid");
        tokenBaseURI = _newBaseURI;
      }
    
      function updateKoCommissionAccount(address _koCommissionAccount)
      external
      onlyIfKnownOrigin {
        require(_koCommissionAccount != address(0), "Invalid address");
        koCommissionAccount = _koCommissionAccount;
      }
    
      /////////////////////
      // Edition Updates //
      /////////////////////
    
      function updateEditionTokenURI(uint256 _editionNumber, string _uri)
      external
      onlyIfKnownOrigin
      onlyRealEdition(_editionNumber) {
        editionNumberToEditionDetails[_editionNumber].tokenURI = _uri;
      }
    
      function updatePriceInWei(uint256 _editionNumber, uint256 _priceInWei)
      external
      onlyIfKnownOrigin
      onlyRealEdition(_editionNumber) {
        editionNumberToEditionDetails[_editionNumber].priceInWei = _priceInWei;
      }
    
      function updateArtistCommission(uint256 _editionNumber, uint256 _rate)
      external
      onlyIfKnownOrigin
      onlyRealEdition(_editionNumber) {
        editionNumberToEditionDetails[_editionNumber].artistCommission = _rate;
      }
    
      function updateArtistsAccount(uint256 _editionNumber, address _artistAccount)
      external
      onlyIfKnownOrigin
      onlyRealEdition(_editionNumber) {
    
        EditionDetails storage _originalEditionDetails = editionNumberToEditionDetails[_editionNumber];
    
        uint256 editionArtistIndex = editionNumberToArtistIndex[_editionNumber];
    
        // Get list of editions old artist works with
        uint256[] storage editionNumbersForArtist = artistToEditionNumbers[_originalEditionDetails.artistAccount];
    
        // Remove edition from artists lists
        delete editionNumbersForArtist[editionArtistIndex];
    
        // Add new artists to the list
        uint256 newArtistsEditionIndex = artistToEditionNumbers[_artistAccount].length;
        artistToEditionNumbers[_artistAccount].push(_editionNumber);
        editionNumberToArtistIndex[_editionNumber] = newArtistsEditionIndex;
    
        // Update the edition
        _originalEditionDetails.artistAccount = _artistAccount;
      }
    
      function updateEditionType(uint256 _editionNumber, uint256 _editionType)
      external
      onlyIfKnownOrigin
      onlyRealEdition(_editionNumber) {
    
        EditionDetails storage _originalEditionDetails = editionNumberToEditionDetails[_editionNumber];
    
        // Get list of editions for old type
        uint256[] storage editionNumbersForType = editionTypeToEditionNumber[_originalEditionDetails.editionType];
    
        // Remove edition from old type list
        uint256 editionTypeIndex = editionNumberToTypeIndex[_editionNumber];
        delete editionNumbersForType[editionTypeIndex];
    
        // Add new type to the list
        uint256 newTypeEditionIndex = editionTypeToEditionNumber[_editionType].length;
        editionTypeToEditionNumber[_editionType].push(_editionNumber);
        editionNumberToTypeIndex[_editionNumber] = newTypeEditionIndex;
    
        // Update the edition
        _originalEditionDetails.editionType = _editionType;
      }
    
      function updateActive(uint256 _editionNumber, bool _active)
      external
      onlyIfKnownOrigin
      onlyRealEdition(_editionNumber) {
        editionNumberToEditionDetails[_editionNumber].active = _active;
      }
    
      function updateTotalSupply(uint256 _editionNumber, uint256 _totalSupply)
      public
      onlyIfKnownOrigin
      onlyRealEdition(_editionNumber) {
        require(tokensOfEdition(_editionNumber).length <= _totalSupply, "Can not lower totalSupply to below the number of tokens already in existence");
        editionNumberToEditionDetails[_editionNumber].totalSupply = _totalSupply;
      }
    
      function updateTotalAvailable(uint256 _editionNumber, uint256 _totalAvailable)
      external
      onlyIfKnownOrigin
      onlyRealEdition(_editionNumber) {
        EditionDetails storage _editionDetails = editionNumberToEditionDetails[_editionNumber];
    
        require(_editionDetails.totalSupply <= _totalAvailable, "Unable to reduce available amount to the below the number totalSupply");
    
        uint256 originalAvailability = _editionDetails.totalAvailable;
        _editionDetails.totalAvailable = _totalAvailable;
        totalNumberAvailable = totalNumberAvailable.sub(originalAvailability).add(_totalAvailable);
      }
    
      function updateStartDate(uint256 _editionNumber, uint256 _startDate)
      external
      onlyIfKnownOrigin
      onlyRealEdition(_editionNumber) {
        editionNumberToEditionDetails[_editionNumber].startDate = _startDate;
      }
    
      function updateEndDate(uint256 _editionNumber, uint256 _endDate)
      external
      onlyIfKnownOrigin
      onlyRealEdition(_editionNumber) {
        editionNumberToEditionDetails[_editionNumber].endDate = _endDate;
      }
    
      function updateOptionalCommission(uint256 _editionNumber, uint256 _rate, address _recipient)
      external
      onlyIfKnownOrigin
      onlyRealEdition(_editionNumber) {
        EditionDetails storage _editionDetails = editionNumberToEditionDetails[_editionNumber];
        uint256 artistCommission = _editionDetails.artistCommission;
    
        if (_rate > 0) {
          require(_recipient != address(0), "Setting a rate must be accompanied by a valid address");
        }
        require(artistCommission.add(_rate) <= 100, "Cant set commission greater than 100%");
    
        editionNumberToOptionalCommissionSplit[_editionNumber] = CommissionSplit({rate : _rate, recipient : _recipient});
      }
    
      ///////////////////
      // Token Updates //
      ///////////////////
    
      function setTokenURI(uint256 _tokenId, string _uri)
      external
      onlyIfKnownOrigin
      onlyValidTokenId(_tokenId) {
        _setTokenURI(_tokenId, _uri);
      }
    
      ///////////////////
      // Query Methods //
      ///////////////////
    
      /**
       * @dev Lookup the edition of the provided token ID
       * @dev Returns 0 if not valid
       */
      function editionOfTokenId(uint256 _tokenId) public view returns (uint256 _editionNumber) {
        return tokenIdToEditionNumber[_tokenId];
      }
    
      /**
       * @dev Lookup all editions added for the given edition type
       * @dev Returns array of edition numbers, any zero edition ids can be ignore/stripped
       */
      function editionsOfType(uint256 _type) public view returns (uint256[] _editionNumbers) {
        return editionTypeToEditionNumber[_type];
      }
    
      /**
       * @dev Lookup all editions for the given artist account
       * @dev Returns empty list if not valid
       */
      function artistsEditions(address _artistsAccount) public view returns (uint256[] _editionNumbers) {
        return artistToEditionNumbers[_artistsAccount];
      }
    
      /**
       * @dev Lookup all tokens minted for the given edition number
       * @dev Returns array of token IDs, any zero edition ids can be ignore/stripped
       */
      function tokensOfEdition(uint256 _editionNumber) public view returns (uint256[] _tokenIds) {
        return editionNumberToTokenIds[_editionNumber];
      }
    
      /**
       * @dev Lookup all owned tokens for the provided address
       * @dev Returns array of token IDs
       */
      function tokensOf(address _owner) public view returns (uint256[] _tokenIds) {
        return ownedTokens[_owner];
      }
    
      /**
       * @dev Checks to see if the edition exists, assumes edition of zero is invalid
       */
      function editionExists(uint256 _editionNumber) public view returns (bool) {
        if (_editionNumber == 0) {
          return false;
        }
        EditionDetails storage editionNumber = editionNumberToEditionDetails[_editionNumber];
        return editionNumber.editionNumber == _editionNumber;
      }
    
      /**
       * @dev Lookup any optional commission split set for the edition
       * @dev Both values will be zero if not present
       */
      function editionOptionalCommission(uint256 _editionNumber) public view returns (uint256 _rate, address _recipient) {
        CommissionSplit storage commission = editionNumberToOptionalCommissionSplit[_editionNumber];
        return (commission.rate, commission.recipient);
      }
    
      /**
       * @dev Main entry point for looking up edition config/metadata
       * @dev Reverts if invalid edition number provided
       */
      function detailsOfEdition(uint256 editionNumber)
      public view
      onlyRealEdition(editionNumber)
      returns (
        bytes32 _editionData,
        uint256 _editionType,
        uint256 _startDate,
        uint256 _endDate,
        address _artistAccount,
        uint256 _artistCommission,
        uint256 _priceInWei,
        string _tokenURI,
        uint256 _totalSupply,
        uint256 _totalAvailable,
        bool _active
      ) {
        EditionDetails storage _editionDetails = editionNumberToEditionDetails[editionNumber];
        return (
        _editionDetails.editionData,
        _editionDetails.editionType,
        _editionDetails.startDate,
        _editionDetails.endDate,
        _editionDetails.artistAccount,
        _editionDetails.artistCommission,
        _editionDetails.priceInWei,
        Strings.strConcat(tokenBaseURI, _editionDetails.tokenURI),
        _editionDetails.totalSupply,
        _editionDetails.totalAvailable,
        _editionDetails.active
        );
      }
    
      /**
       * @dev Lookup a tokens common identifying characteristics
       * @dev Reverts if invalid token ID provided
       */
      function tokenData(uint256 _tokenId)
      public view
      onlyValidTokenId(_tokenId)
      returns (
        uint256 _editionNumber,
        uint256 _editionType,
        bytes32 _editionData,
        string _tokenURI,
        address _owner
      ) {
        uint256 editionNumber = tokenIdToEditionNumber[_tokenId];
        EditionDetails storage editionDetails = editionNumberToEditionDetails[editionNumber];
        return (
        editionNumber,
        editionDetails.editionType,
        editionDetails.editionData,
        tokenURI(_tokenId),
        ownerOf(_tokenId)
        );
      }
    
      function tokenURI(uint256 _tokenId) public view onlyValidTokenId(_tokenId) returns (string) {
        return Strings.strConcat(tokenBaseURI, tokenURIs[_tokenId]);
      }
    
      function tokenURISafe(uint256 _tokenId) public view returns (string) {
        return Strings.strConcat(tokenBaseURI, tokenURIs[_tokenId]);
      }
    
      function purchaseDatesToken(uint256 _tokenId) public view returns (uint256 _startDate, uint256 _endDate) {
        uint256 _editionNumber = tokenIdToEditionNumber[_tokenId];
        return purchaseDatesEdition(_editionNumber);
      }
    
      function priceInWeiToken(uint256 _tokenId) public view returns (uint256 _priceInWei) {
        uint256 _editionNumber = tokenIdToEditionNumber[_tokenId];
        return priceInWeiEdition(_editionNumber);
      }
    
      //////////////////////////
      // Edition config query //
      //////////////////////////
    
      function editionData(uint256 _editionNumber) public view returns (bytes32) {
        EditionDetails storage _editionDetails = editionNumberToEditionDetails[_editionNumber];
        return _editionDetails.editionData;
      }
    
      function editionType(uint256 _editionNumber) public view returns (uint256) {
        EditionDetails storage _editionDetails = editionNumberToEditionDetails[_editionNumber];
        return _editionDetails.editionType;
      }
    
      function purchaseDatesEdition(uint256 _editionNumber) public view returns (uint256 _startDate, uint256 _endDate) {
        EditionDetails storage _editionDetails = editionNumberToEditionDetails[_editionNumber];
        return (
        _editionDetails.startDate,
        _editionDetails.endDate
        );
      }
    
      function artistCommission(uint256 _editionNumber) public view returns (address _artistAccount, uint256 _artistCommission) {
        EditionDetails storage _editionDetails = editionNumberToEditionDetails[_editionNumber];
        return (
        _editionDetails.artistAccount,
        _editionDetails.artistCommission
        );
      }
    
      function priceInWeiEdition(uint256 _editionNumber) public view returns (uint256 _priceInWei) {
        EditionDetails storage _editionDetails = editionNumberToEditionDetails[_editionNumber];
        return _editionDetails.priceInWei;
      }
    
      function tokenURIEdition(uint256 _editionNumber) public view returns (string) {
        EditionDetails storage _editionDetails = editionNumberToEditionDetails[_editionNumber];
        return Strings.strConcat(tokenBaseURI, _editionDetails.tokenURI);
      }
    
      function editionActive(uint256 _editionNumber) public view returns (bool) {
        EditionDetails storage _editionDetails = editionNumberToEditionDetails[_editionNumber];
        return _editionDetails.active;
      }
    
      function totalRemaining(uint256 _editionNumber) public view returns (uint256) {
        EditionDetails storage _editionDetails = editionNumberToEditionDetails[_editionNumber];
        return _editionDetails.totalAvailable.sub(_editionDetails.totalSupply);
      }
    
      function totalAvailableEdition(uint256 _editionNumber) public view returns (uint256) {
        EditionDetails storage _editionDetails = editionNumberToEditionDetails[_editionNumber];
        return _editionDetails.totalAvailable;
      }
    
      function totalSupplyEdition(uint256 _editionNumber) public view returns (uint256) {
        EditionDetails storage _editionDetails = editionNumberToEditionDetails[_editionNumber];
        return _editionDetails.totalSupply;
      }
    
    }