// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

import "./OFTCoreV2.sol";
import "./IOFTV2.sol";
import "./ERC165.sol";

abstract contract BaseOFTV2 is OFTCoreV2, ERC165, IOFTV2 {
  constructor(uint8 _sharedDecimals, address _lzEndpoint)
    OFTCoreV2(_sharedDecimals, _lzEndpoint)
  {}

  /**
   *
   * public functions
   *
   */
  function sendFrom(
    address _from,
    uint16 _dstChainId,
    bytes32 _toAddress,
    uint256 _amount,
    LzCallParams calldata _callParams
  ) public payable virtual override {
    _send(
      _from,
      _dstChainId,
      _toAddress,
      _amount,
      _callParams.refundAddress,
      _callParams.zroPaymentAddress,
      _callParams.adapterParams
    );
  }

  function sendAndCall(
    address _from,
    uint16 _dstChainId,
    bytes32 _toAddress,
    uint256 _amount,
    bytes calldata _payload,
    uint64 _dstGasForCall,
    LzCallParams calldata _callParams
  ) public payable virtual override {
    _sendAndCall(
      _from,
      _dstChainId,
      _toAddress,
      _amount,
      _payload,
      _dstGasForCall,
      _callParams.refundAddress,
      _callParams.zroPaymentAddress,
      _callParams.adapterParams
    );
  }

  /**
   *
   * public view functions
   *
   */
  function supportsInterface(bytes4 interfaceId)
    public
    view
    virtual
    override(ERC165, IERC165)
    returns (bool)
  {
    return interfaceId == type(IOFTV2).interfaceId
      || super.supportsInterface(interfaceId);
  }

  function estimateSendFee(
    uint16 _dstChainId,
    bytes32 _toAddress,
    uint256 _amount,
    bool _useZro,
    bytes calldata _adapterParams
  ) public view virtual override returns (uint256 nativeFee, uint256 zroFee) {
    return _estimateSendFee(
      _dstChainId, _toAddress, _amount, _useZro, _adapterParams
    );
  }

  function estimateSendAndCallFee(
    uint16 _dstChainId,
    bytes32 _toAddress,
    uint256 _amount,
    bytes calldata _payload,
    uint64 _dstGasForCall,
    bool _useZro,
    bytes calldata _adapterParams
  ) public view virtual override returns (uint256 nativeFee, uint256 zroFee) {
    return _estimateSendAndCallFee(
      _dstChainId,
      _toAddress,
      _amount,
      _payload,
      _dstGasForCall,
      _useZro,
      _adapterParams
    );
  }

  function circulatingSupply() public view virtual override returns (uint256);

  function token() public view virtual override returns (address);
}

// SPDX-License-Identifier: Unlicense
/*
 * @title Solidity Bytes Arrays Utils
 * @author Gonçalo Sá <goncalo.sa@consensys.net>
 *
 * @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 >=0.8.0 <0.9.0;

library BytesLib {
  function concat(bytes memory _preBytes, bytes memory _postBytes)
    internal
    pure
    returns (bytes memory)
  {
    bytes memory tempBytes;

    assembly {
      // Get a location of some free memory and store it in tempBytes as
      // Solidity does for memory variables.
      tempBytes := mload(0x40)

      // Store the length of the first bytes array at the beginning of
      // the memory for tempBytes.
      let length := mload(_preBytes)
      mstore(tempBytes, length)

      // Maintain a memory counter for the current write location in the
      // temp bytes array by adding the 32 bytes for the array length to
      // the starting location.
      let mc := add(tempBytes, 0x20)
      // Stop copying when the memory counter reaches the length of the
      // first bytes array.
      let end := add(mc, length)

      for {
        // Initialize a copy counter to the start of the _preBytes data,
        // 32 bytes into its memory.
        let cc := add(_preBytes, 0x20)
      } lt(mc, end) {
        // Increase both counters by 32 bytes each iteration.
        mc := add(mc, 0x20)
        cc := add(cc, 0x20)
      } {
        // Write the _preBytes data into the tempBytes memory 32 bytes
        // at a time.
        mstore(mc, mload(cc))
      }

      // Add the length of _postBytes to the current length of tempBytes
      // and store it as the new length in the first 32 bytes of the
      // tempBytes memory.
      length := mload(_postBytes)
      mstore(tempBytes, add(length, mload(tempBytes)))

      // Move the memory counter back from a multiple of 0x20 to the
      // actual end of the _preBytes data.
      mc := end
      // Stop copying when the memory counter reaches the new combined
      // length of the arrays.
      end := add(mc, length)

      for { let cc := add(_postBytes, 0x20) } lt(mc, end) {
        mc := add(mc, 0x20)
        cc := add(cc, 0x20)
      } { mstore(mc, mload(cc)) }

      // Update the free-memory pointer by padding our last write location
      // to 32 bytes: add 31 bytes to the end of tempBytes to move to the
      // next 32 byte block, then round down to the nearest multiple of
      // 32. If the sum of the length of the two arrays is zero then add
      // one before rounding down to leave a blank 32 bytes (the length block with 0).
      mstore(
        0x40,
        and(
          add(add(end, iszero(add(length, mload(_preBytes)))), 31),
          not(31) // Round down to the nearest 32 bytes.
        )
      )
    }

    return tempBytes;
  }

  function concatStorage(bytes storage _preBytes, bytes memory _postBytes)
    internal
  {
    assembly {
      // Read the first 32 bytes of _preBytes storage, which is the length
      // of the array. (We don't need to use the offset into the slot
      // because arrays use the entire slot.)
      let fslot := sload(_preBytes.slot)
      // Arrays of 31 bytes or less have an even value in their slot,
      // while longer arrays have an odd value. The actual length is
      // the slot divided by two for odd values, and the lowest order
      // byte divided by two for even values.
      // If the slot is even, bitwise and the slot with 255 and divide by
      // two to get the length. If the slot is odd, bitwise and the slot
      // with -1 and divide by two.
      let slength :=
        div(and(fslot, sub(mul(0x100, iszero(and(fslot, 1))), 1)), 2)
      let mlength := mload(_postBytes)
      let newlength := add(slength, mlength)
      // slength can contain both the length and contents of the array
      // if length < 32 bytes so let's prepare for that
      // v. http://solidity.readthedocs.io/en/latest/miscellaneous.html#layout-of-state-variables-in-storage
      switch add(lt(slength, 32), lt(newlength, 32))
      case 2 {
        // Since the new array still fits in the slot, we just need to
        // update the contents of the slot.
        // uint256(bytes_storage) = uint256(bytes_storage) + uint256(bytes_memory) + new_length
        sstore(
          _preBytes.slot,
          // all the modifications to the slot are inside this
          // next block
          add(
            // we can just add to the slot contents because the
            // bytes we want to change are the LSBs
            fslot,
            add(
              mul(
                div(
                  // load the bytes from memory
                  mload(add(_postBytes, 0x20)),
                  // zero all bytes to the right
                  exp(0x100, sub(32, mlength))
                ),
                // and now shift left the number of bytes to
                // leave space for the length in the slot
                exp(0x100, sub(32, newlength))
              ),
              // increase length by the double of the memory
              // bytes length
              mul(mlength, 2)
            )
          )
        )
      }
      case 1 {
        // The stored value fits in the slot, but the combined value
        // will exceed it.
        // get the keccak hash to get the contents of the array
        mstore(0x0, _preBytes.slot)
        let sc := add(keccak256(0x0, 0x20), div(slength, 32))

        // save new length
        sstore(_preBytes.slot, add(mul(newlength, 2), 1))

        // The contents of the _postBytes array start 32 bytes into
        // the structure. Our first read should obtain the `submod`
        // bytes that can fit into the unused space in the last word
        // of the stored array. To get this, we read 32 bytes starting
        // from `submod`, so the data we read overlaps with the array
        // contents by `submod` bytes. Masking the lowest-order
        // `submod` bytes allows us to add that value directly to the
        // stored value.

        let submod := sub(32, slength)
        let mc := add(_postBytes, submod)
        let end := add(_postBytes, mlength)
        let mask := sub(exp(0x100, submod), 1)

        sstore(
          sc,
          add(
            and(
              fslot,
              0xffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff00
            ),
            and(mload(mc), mask)
          )
        )

        for {
          mc := add(mc, 0x20)
          sc := add(sc, 1)
        } lt(mc, end) {
          sc := add(sc, 1)
          mc := add(mc, 0x20)
        } { sstore(sc, mload(mc)) }

        mask := exp(0x100, sub(mc, end))

        sstore(sc, mul(div(mload(mc), mask), mask))
      }
      default {
        // get the keccak hash to get the contents of the array
        mstore(0x0, _preBytes.slot)
        // Start copying to the last used word of the stored array.
        let sc := add(keccak256(0x0, 0x20), div(slength, 32))

        // save new length
        sstore(_preBytes.slot, add(mul(newlength, 2), 1))

        // Copy over the first `submod` bytes of the new data as in
        // case 1 above.
        let slengthmod := mod(slength, 32)
        let mlengthmod := mod(mlength, 32)
        let submod := sub(32, slengthmod)
        let mc := add(_postBytes, submod)
        let end := add(_postBytes, mlength)
        let mask := sub(exp(0x100, submod), 1)

        sstore(sc, add(sload(sc), and(mload(mc), mask)))

        for {
          sc := add(sc, 1)
          mc := add(mc, 0x20)
        } lt(mc, end) {
          sc := add(sc, 1)
          mc := add(mc, 0x20)
        } { sstore(sc, mload(mc)) }

        mask := exp(0x100, sub(mc, end))

        sstore(sc, mul(div(mload(mc), mask), mask))
      }
    }
  }

  function slice(bytes memory _bytes, uint256 _start, uint256 _length)
    internal
    pure
    returns (bytes memory)
  {
    require(_length + 31 >= _length, "slice_overflow");
    require(_bytes.length >= _start + _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 toAddress(bytes memory _bytes, uint256 _start)
    internal
    pure
    returns (address)
  {
    require(_bytes.length >= _start + 20, "toAddress_outOfBounds");
    address tempAddress;

    assembly {
      tempAddress :=
        div(mload(add(add(_bytes, 0x20), _start)), 0x1000000000000000000000000)
    }

    return tempAddress;
  }

  function toUint8(bytes memory _bytes, uint256 _start)
    internal
    pure
    returns (uint8)
  {
    require(_bytes.length >= _start + 1, "toUint8_outOfBounds");
    uint8 tempUint;

    assembly {
      tempUint := mload(add(add(_bytes, 0x1), _start))
    }

    return tempUint;
  }

  function toUint16(bytes memory _bytes, uint256 _start)
    internal
    pure
    returns (uint16)
  {
    require(_bytes.length >= _start + 2, "toUint16_outOfBounds");
    uint16 tempUint;

    assembly {
      tempUint := mload(add(add(_bytes, 0x2), _start))
    }

    return tempUint;
  }

  function toUint32(bytes memory _bytes, uint256 _start)
    internal
    pure
    returns (uint32)
  {
    require(_bytes.length >= _start + 4, "toUint32_outOfBounds");
    uint32 tempUint;

    assembly {
      tempUint := mload(add(add(_bytes, 0x4), _start))
    }

    return tempUint;
  }

  function toUint64(bytes memory _bytes, uint256 _start)
    internal
    pure
    returns (uint64)
  {
    require(_bytes.length >= _start + 8, "toUint64_outOfBounds");
    uint64 tempUint;

    assembly {
      tempUint := mload(add(add(_bytes, 0x8), _start))
    }

    return tempUint;
  }

  function toUint96(bytes memory _bytes, uint256 _start)
    internal
    pure
    returns (uint96)
  {
    require(_bytes.length >= _start + 12, "toUint96_outOfBounds");
    uint96 tempUint;

    assembly {
      tempUint := mload(add(add(_bytes, 0xc), _start))
    }

    return tempUint;
  }

  function toUint128(bytes memory _bytes, uint256 _start)
    internal
    pure
    returns (uint128)
  {
    require(_bytes.length >= _start + 16, "toUint128_outOfBounds");
    uint128 tempUint;

    assembly {
      tempUint := mload(add(add(_bytes, 0x10), _start))
    }

    return tempUint;
  }

  function toUint256(bytes memory _bytes, uint256 _start)
    internal
    pure
    returns (uint256)
  {
    require(_bytes.length >= _start + 32, "toUint256_outOfBounds");
    uint256 tempUint;

    assembly {
      tempUint := mload(add(add(_bytes, 0x20), _start))
    }

    return tempUint;
  }

  function toBytes32(bytes memory _bytes, uint256 _start)
    internal
    pure
    returns (bytes32)
  {
    require(_bytes.length >= _start + 32, "toBytes32_outOfBounds");
    bytes32 tempBytes32;

    assembly {
      tempBytes32 := mload(add(add(_bytes, 0x20), _start))
    }

    return tempBytes32;
  }

  function equal(bytes memory _preBytes, bytes memory _postBytes)
    internal
    pure
    returns (bool)
  {
    bool success = true;

    assembly {
      let length := mload(_preBytes)

      // if lengths don't match the arrays are not equal
      switch eq(length, mload(_postBytes))
      case 1 {
        // cb is a circuit breaker in the for loop since there's
        //  no said feature for inline assembly loops
        // cb = 1 - don't breaker
        // cb = 0 - break
        let cb := 1

        let mc := add(_preBytes, 0x20)
        let end := add(mc, length)

        for { let cc := add(_postBytes, 0x20) }
        // the next line is the loop condition:
        // while(uint256(mc < end) + cb == 2)
        eq(add(lt(mc, end), cb), 2) {
          mc := add(mc, 0x20)
          cc := add(cc, 0x20)
        } {
          // if any of these checks fails then arrays are not equal
          if iszero(eq(mload(mc), mload(cc))) {
            // unsuccess:
            success := 0
            cb := 0
          }
        }
      }
      default {
        // unsuccess:
        success := 0
      }
    }

    return success;
  }

  function equalStorage(bytes storage _preBytes, bytes memory _postBytes)
    internal
    view
    returns (bool)
  {
    bool success = true;

    assembly {
      // we know _preBytes_offset is 0
      let fslot := sload(_preBytes.slot)
      // Decode the length of the stored array like in concatStorage().
      let slength :=
        div(and(fslot, sub(mul(0x100, iszero(and(fslot, 1))), 1)), 2)
      let mlength := mload(_postBytes)

      // if lengths don't match the arrays are not equal
      switch eq(slength, mlength)
      case 1 {
        // slength can contain both the length and contents of the array
        // if length < 32 bytes so let's prepare for that
        // v. http://solidity.readthedocs.io/en/latest/miscellaneous.html#layout-of-state-variables-in-storage
        if iszero(iszero(slength)) {
          switch lt(slength, 32)
          case 1 {
            // blank the last byte which is the length
            fslot := mul(div(fslot, 0x100), 0x100)

            if iszero(eq(fslot, mload(add(_postBytes, 0x20)))) {
              // unsuccess:
              success := 0
            }
          }
          default {
            // cb is a circuit breaker in the for loop since there's
            //  no said feature for inline assembly loops
            // cb = 1 - don't breaker
            // cb = 0 - break
            let cb := 1

            // get the keccak hash to get the contents of the array
            mstore(0x0, _preBytes.slot)
            let sc := keccak256(0x0, 0x20)

            let mc := add(_postBytes, 0x20)
            let end := add(mc, mlength)

            // the next line is the loop condition:
            // while(uint256(mc < end) + cb == 2)
            for {} eq(add(lt(mc, end), cb), 2) {
              sc := add(sc, 1)
              mc := add(mc, 0x20)
            } {
              if iszero(eq(sload(sc), mload(mc))) {
                // unsuccess:
                success := 0
                cb := 0
              }
            }
          }
        }
      }
      default {
        // unsuccess:
        success := 0
      }
    }

    return success;
  }
}

// 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
// OpenZeppelin Contracts v4.4.1 (utils/introspection/ERC165.sol)

pragma solidity ^0.8.0;

import "./IERC165.sol";

/**
 * @dev Implementation of the {IERC165} interface.
 *
 * Contracts that want to implement ERC165 should inherit from this contract and override {supportsInterface} to check
 * for the additional interface id that will be supported. For example:
 *
 * ```solidity
 * function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
 *     return interfaceId == type(MyInterface).interfaceId || super.supportsInterface(interfaceId);
 * }
 * ```
 *
 * Alternatively, {ERC165Storage} provides an easier to use but more expensive implementation.
 */
abstract contract ERC165 is IERC165 {
  /**
   * @dev See {IERC165-supportsInterface}.
   */
  function supportsInterface(bytes4 interfaceId)
    public
    view
    virtual
    override
    returns (bool)
  {
    return interfaceId == type(IERC165).interfaceId;
  }
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.8.0) (token/ERC20/ERC20.sol)

pragma solidity ^0.8.0;

import "./IERC20.sol";
import "./IERC20Metadata.sol";
import "./Context.sol";

/**
 * @dev Implementation of the {IERC20} interface.
 *
 * This implementation is agnostic to the way tokens are created. This means
 * that a supply mechanism has to be added in a derived contract using {_mint}.
 * For a generic mechanism see {ERC20PresetMinterPauser}.
 *
 * TIP: For a detailed writeup see our guide
 * https://forum.openzeppelin.com/t/how-to-implement-erc20-supply-mechanisms/226[How
 * to implement supply mechanisms].
 *
 * We have followed general OpenZeppelin Contracts guidelines: functions revert
 * instead returning `false` on failure. This behavior is nonetheless
 * conventional and does not conflict with the expectations of ERC20
 * applications.
 *
 * Additionally, an {Approval} event is emitted on calls to {transferFrom}.
 * This allows applications to reconstruct the allowance for all accounts just
 * by listening to said events. Other implementations of the EIP may not emit
 * these events, as it isn't required by the specification.
 *
 * Finally, the non-standard {decreaseAllowance} and {increaseAllowance}
 * functions have been added to mitigate the well-known issues around setting
 * allowances. See {IERC20-approve}.
 */
contract ERC20 is Context, IERC20, IERC20Metadata {
  mapping(address => uint256) private _balances;

  mapping(address => mapping(address => uint256)) private _allowances;

  uint256 private _totalSupply;

  string private _name;
  string private _symbol;

  /**
   * @dev Sets the values for {name} and {symbol}.
   *
   * The default value of {decimals} is 18. To select a different value for
   * {decimals} you should overload it.
   *
   * All two of these values are immutable: they can only be set once during
   * construction.
   */
  constructor(string memory name_, string memory symbol_) {
    _name = name_;
    _symbol = symbol_;
  }

  /**
   * @dev Returns the name of the token.
   */
  function name() public view virtual override returns (string memory) {
    return _name;
  }

  /**
   * @dev Returns the symbol of the token, usually a shorter version of the
   * name.
   */
  function symbol() public view virtual override returns (string memory) {
    return _symbol;
  }

  /**
   * @dev Returns the number of decimals used to get its user representation.
   * For example, if `decimals` equals `2`, a balance of `505` tokens should
   * be displayed to a user as `5.05` (`505 / 10 ** 2`).
   *
   * Tokens usually opt for a value of 18, imitating the relationship between
   * Ether and Wei. This is the value {ERC20} uses, unless this function is
   * overridden;
   *
   * NOTE: This information is only used for _display_ purposes: it in
   * no way affects any of the arithmetic of the contract, including
   * {IERC20-balanceOf} and {IERC20-transfer}.
   */
  function decimals() public view virtual override returns (uint8) {
    return 18;
  }

  /**
   * @dev See {IERC20-totalSupply}.
   */
  function totalSupply() public view virtual override returns (uint256) {
    return _totalSupply;
  }

  /**
   * @dev See {IERC20-balanceOf}.
   */
  function balanceOf(address account)
    public
    view
    virtual
    override
    returns (uint256)
  {
    return _balances[account];
  }

  /**
   * @dev See {IERC20-transfer}.
   *
   * Requirements:
   *
   * - `to` cannot be the zero address.
   * - the caller must have a balance of at least `amount`.
   */
  function transfer(address to, uint256 amount)
    public
    virtual
    override
    returns (bool)
  {
    address owner = _msgSender();
    _transfer(owner, to, amount);
    return true;
  }

  /**
   * @dev See {IERC20-allowance}.
   */
  function allowance(address owner, address spender)
    public
    view
    virtual
    override
    returns (uint256)
  {
    return _allowances[owner][spender];
  }

  /**
   * @dev See {IERC20-approve}.
   *
   * NOTE: If `amount` is the maximum `uint256`, the allowance is not updated on
   * `transferFrom`. This is semantically equivalent to an infinite approval.
   *
   * Requirements:
   *
   * - `spender` cannot be the zero address.
   */
  function approve(address spender, uint256 amount)
    public
    virtual
    override
    returns (bool)
  {
    address owner = _msgSender();
    _approve(owner, spender, amount);
    return true;
  }

  /**
   * @dev See {IERC20-transferFrom}.
   *
   * Emits an {Approval} event indicating the updated allowance. This is not
   * required by the EIP. See the note at the beginning of {ERC20}.
   *
   * NOTE: Does not update the allowance if the current allowance
   * is the maximum `uint256`.
   *
   * Requirements:
   *
   * - `from` and `to` cannot be the zero address.
   * - `from` must have a balance of at least `amount`.
   * - the caller must have allowance for ``from``'s tokens of at least
   * `amount`.
   */
  function transferFrom(address from, address to, uint256 amount)
    public
    virtual
    override
    returns (bool)
  {
    address spender = _msgSender();
    _spendAllowance(from, spender, amount);
    _transfer(from, to, amount);
    return true;
  }

  /**
   * @dev Atomically increases the allowance granted to `spender` by the caller.
   *
   * This is an alternative to {approve} that can be used as a mitigation for
   * problems described in {IERC20-approve}.
   *
   * Emits an {Approval} event indicating the updated allowance.
   *
   * Requirements:
   *
   * - `spender` cannot be the zero address.
   */
  function increaseAllowance(address spender, uint256 addedValue)
    public
    virtual
    returns (bool)
  {
    address owner = _msgSender();
    _approve(owner, spender, allowance(owner, spender) + addedValue);
    return true;
  }

  /**
   * @dev Atomically decreases the allowance granted to `spender` by the caller.
   *
   * This is an alternative to {approve} that can be used as a mitigation for
   * problems described in {IERC20-approve}.
   *
   * Emits an {Approval} event indicating the updated allowance.
   *
   * Requirements:
   *
   * - `spender` cannot be the zero address.
   * - `spender` must have allowance for the caller of at least
   * `subtractedValue`.
   */
  function decreaseAllowance(address spender, uint256 subtractedValue)
    public
    virtual
    returns (bool)
  {
    address owner = _msgSender();
    uint256 currentAllowance = allowance(owner, spender);
    require(
      currentAllowance >= subtractedValue,
      "ERC20: decreased allowance below zero"
    );
    unchecked {
      _approve(owner, spender, currentAllowance - subtractedValue);
    }

    return true;
  }

  /**
   * @dev Moves `amount` of tokens from `from` to `to`.
   *
   * This internal function is equivalent to {transfer}, and can be used to
   * e.g. implement automatic token fees, slashing mechanisms, etc.
   *
   * Emits a {Transfer} event.
   *
   * Requirements:
   *
   * - `from` cannot be the zero address.
   * - `to` cannot be the zero address.
   * - `from` must have a balance of at least `amount`.
   */
  function _transfer(address from, address to, uint256 amount) internal virtual {
    require(from != address(0), "ERC20: transfer from the zero address");
    require(to != address(0), "ERC20: transfer to the zero address");

    _beforeTokenTransfer(from, to, amount);

    uint256 fromBalance = _balances[from];
    require(fromBalance >= amount, "ERC20: transfer amount exceeds balance");
    unchecked {
      _balances[from] = fromBalance - amount;
      // Overflow not possible: the sum of all balances is capped by totalSupply, and the sum is preserved by
      // decrementing then incrementing.
      _balances[to] += amount;
    }

    emit Transfer(from, to, amount);

    _afterTokenTransfer(from, to, amount);
  }

  /**
   * @dev Creates `amount` tokens and assigns them to `account`, increasing
   * the total supply.
   *
   * Emits a {Transfer} event with `from` set to the zero address.
   *
   * Requirements:
   *
   * - `account` cannot be the zero address.
   */
  function _mint(address account, uint256 amount) internal virtual {
    require(account != address(0), "ERC20: mint to the zero address");

    _beforeTokenTransfer(address(0), account, amount);

    _totalSupply += amount;
    unchecked {
      // Overflow not possible: balance + amount is at most totalSupply + amount, which is checked above.
      _balances[account] += amount;
    }
    emit Transfer(address(0), account, amount);

    _afterTokenTransfer(address(0), account, amount);
  }

  /**
   * @dev Destroys `amount` tokens from `account`, reducing the
   * total supply.
   *
   * Emits a {Transfer} event with `to` set to the zero address.
   *
   * Requirements:
   *
   * - `account` cannot be the zero address.
   * - `account` must have at least `amount` tokens.
   */
  function _burn(address account, uint256 amount) internal virtual {
    require(account != address(0), "ERC20: burn from the zero address");

    _beforeTokenTransfer(account, address(0), amount);

    uint256 accountBalance = _balances[account];
    require(accountBalance >= amount, "ERC20: burn amount exceeds balance");
    unchecked {
      _balances[account] = accountBalance - amount;
      // Overflow not possible: amount <= accountBalance <= totalSupply.
      _totalSupply -= amount;
    }

    emit Transfer(account, address(0), amount);

    _afterTokenTransfer(account, address(0), amount);
  }

  /**
   * @dev Sets `amount` as the allowance of `spender` over the `owner` s tokens.
   *
   * This internal function is equivalent to `approve`, and can be used to
   * e.g. set automatic allowances for certain subsystems, etc.
   *
   * Emits an {Approval} event.
   *
   * Requirements:
   *
   * - `owner` cannot be the zero address.
   * - `spender` cannot be the zero address.
   */
  function _approve(address owner, address spender, uint256 amount)
    internal
    virtual
  {
    require(owner != address(0), "ERC20: approve from the zero address");
    require(spender != address(0), "ERC20: approve to the zero address");

    _allowances[owner][spender] = amount;
    emit Approval(owner, spender, amount);
  }

  /**
   * @dev Updates `owner` s allowance for `spender` based on spent `amount`.
   *
   * Does not update the allowance amount in case of infinite allowance.
   * Revert if not enough allowance is available.
   *
   * Might emit an {Approval} event.
   */
  function _spendAllowance(address owner, address spender, uint256 amount)
    internal
    virtual
  {
    uint256 currentAllowance = allowance(owner, spender);
    if (currentAllowance != type(uint256).max) {
      require(currentAllowance >= amount, "ERC20: insufficient allowance");
      unchecked {
        _approve(owner, spender, currentAllowance - amount);
      }
    }
  }

  /**
   * @dev Hook that is called before any transfer of tokens. This includes
   * minting and burning.
   *
   * Calling conditions:
   *
   * - when `from` and `to` are both non-zero, `amount` of ``from``'s tokens
   * will be transferred to `to`.
   * - when `from` is zero, `amount` tokens will be minted for `to`.
   * - when `to` is zero, `amount` of ``from``'s tokens will be burned.
   * - `from` and `to` are never both zero.
   *
   * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
   */
  function _beforeTokenTransfer(address from, address to, uint256 amount)
    internal
    virtual
  {}

  /**
   * @dev Hook that is called after any transfer of tokens. This includes
   * minting and burning.
   *
   * Calling conditions:
   *
   * - when `from` and `to` are both non-zero, `amount` of ``from``'s tokens
   * has been transferred to `to`.
   * - when `from` is zero, `amount` tokens have been minted for `to`.
   * - when `to` is zero, `amount` of ``from``'s tokens have been burned.
   * - `from` and `to` are never both zero.
   *
   * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
   */
  function _afterTokenTransfer(address from, address to, uint256 amount)
    internal
    virtual
  {}
}

// SPDX-License-Identifier: MIT OR Apache-2.0
pragma solidity >=0.7.6;

library ExcessivelySafeCall {
  uint256 constant LOW_28_MASK =
    0x00000000ffffffffffffffffffffffffffffffffffffffffffffffffffffffff;

  /// @notice Use when you _really_ really _really_ don't trust the called
  /// contract. This prevents the called contract from causing reversion of
  /// the caller in as many ways as we can.
  /// @dev The main difference between this and a solidity low-level call is
  /// that we limit the number of bytes that the callee can cause to be
  /// copied to caller memory. This prevents stupid things like malicious
  /// contracts returning 10,000,000 bytes causing a local OOG when copying
  /// to memory.
  /// @param _target The address to call
  /// @param _gas The amount of gas to forward 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 excessivelySafeCall(
    address _target,
    uint256 _gas,
    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
          0, // 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);
  }

  /// @notice Use when you _really_ really _really_ don't trust the called
  /// contract. This prevents the called contract from causing reversion of
  /// the caller in as many ways as we can.
  /// @dev The main difference between this and a solidity low-level call is
  /// that we limit the number of bytes that the callee can cause to be
  /// copied to caller memory. This prevents stupid things like malicious
  /// contracts returning 10,000,000 bytes causing a local OOG when copying
  /// to memory.
  /// @param _target The address to call
  /// @param _gas The amount of gas to forward 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 excessivelySafeStaticCall(
    address _target,
    uint256 _gas,
    uint16 _maxCopy,
    bytes memory _calldata
  ) internal view 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 :=
        staticcall(
          _gas, // gas
          _target, // recipient
          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);
  }

  /**
   * @notice Swaps function selectors in encoded contract calls
   * @dev Allows reuse of encoded calldata for functions with identical
   * argument types but different names. It simply swaps out the first 4 bytes
   * for the new selector. This function modifies memory in place, and should
   * only be used with caution.
   * @param _newSelector The new 4-byte selector
   * @param _buf The encoded contract args
   */
  function swapSelector(bytes4 _newSelector, bytes memory _buf) internal pure {
    require(_buf.length >= 4);
    uint256 _mask = LOW_28_MASK;
    assembly {
      // load the first word of
      let _word := mload(add(_buf, 0x20))
      // mask out the top 4 bytes
      // /x
      _word := and(_word, _mask)
      _word := or(_newSelector, _word)
      mstore(add(_buf, 0x20), _word)
    }
  }
}

// SPDX-License-Identifier: MIT

pragma solidity >=0.5.0;

import "./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,
    uint256 _amount,
    bool _useZro,
    bytes calldata _adapterParams
  ) external view returns (uint256 nativeFee, uint256 zroFee);

  function estimateSendAndCallFee(
    uint16 _dstChainId,
    bytes32 _toAddress,
    uint256 _amount,
    bytes calldata _payload,
    uint64 _dstGasForCall,
    bool _useZro,
    bytes calldata _adapterParams
  ) external view returns (uint256 nativeFee, uint256 zroFee);

  /**
   * @dev returns the circulating amount of tokens on current chain
   */
  function circulatingSupply() external view returns (uint256);

  /**
   * @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);
}

// 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 v4.4.1 (token/ERC20/extensions/IERC20Metadata.sol)

pragma solidity ^0.8.0;

import "./IERC20.sol";

/**
 * @dev Interface for the optional metadata functions from the ERC20 standard.
 *
 * _Available since v4.1._
 */
interface IERC20Metadata is IERC20 {
  /**
   * @dev Returns the name of the token.
   */
  function name() external view returns (string memory);

  /**
   * @dev Returns the symbol of the token.
   */
  function symbol() external view returns (string memory);

  /**
   * @dev Returns the decimals places of the token.
   */
  function decimals() external view returns (uint8);
}

// SPDX-License-Identifier: MIT

pragma solidity >=0.5.0;

import "./ILayerZeroUserApplicationConfig.sol";

interface ILayerZeroEndpoint is ILayerZeroUserApplicationConfig {
  // @notice send a LayerZero message to the specified address at a LayerZero endpoint.
  // @param _dstChainId - the destination chain identifier
  // @param _destination - the address on destination chain (in bytes). address length/format may vary by chains
  // @param _payload - a custom bytes payload to send to the destination contract
  // @param _refundAddress - if the source transaction is cheaper than the amount of value passed, refund the additional amount to this address
  // @param _zroPaymentAddress - the address of the ZRO token holder who would pay for the transaction
  // @param _adapterParams - parameters for custom functionality. e.g. receive airdropped native gas from the relayer on destination
  function send(
    uint16 _dstChainId,
    bytes calldata _destination,
    bytes calldata _payload,
    address payable _refundAddress,
    address _zroPaymentAddress,
    bytes calldata _adapterParams
  ) external payable;

  // @notice used by the messaging library to publish verified payload
  // @param _srcChainId - the source chain identifier
  // @param _srcAddress - the source contract (as bytes) at the source chain
  // @param _dstAddress - the address on destination chain
  // @param _nonce - the unbound message ordering nonce
  // @param _gasLimit - the gas limit for external contract execution
  // @param _payload - verified payload to send to the destination contract
  function receivePayload(
    uint16 _srcChainId,
    bytes calldata _srcAddress,
    address _dstAddress,
    uint64 _nonce,
    uint256 _gasLimit,
    bytes calldata _payload
  ) external;

  // @notice get the inboundNonce of a lzApp from a source chain which could be EVM or non-EVM chain
  // @param _srcChainId - the source chain identifier
  // @param _srcAddress - the source chain contract address
  function getInboundNonce(uint16 _srcChainId, bytes calldata _srcAddress)
    external
    view
    returns (uint64);

  // @notice get the outboundNonce from this source chain which, consequently, is always an EVM
  // @param _srcAddress - the source chain contract address
  function getOutboundNonce(uint16 _dstChainId, address _srcAddress)
    external
    view
    returns (uint64);

  // @notice gets a quote in source native gas, for the amount that send() requires to pay for message delivery
  // @param _dstChainId - the destination chain identifier
  // @param _userApplication - the user app address on this EVM chain
  // @param _payload - the custom message to send over LayerZero
  // @param _payInZRO - if false, user app pays the protocol fee in native token
  // @param _adapterParam - parameters for the adapter service, e.g. send some dust native token to dstChain
  function estimateFees(
    uint16 _dstChainId,
    address _userApplication,
    bytes calldata _payload,
    bool _payInZRO,
    bytes calldata _adapterParam
  ) external view returns (uint256 nativeFee, uint256 zroFee);

  // @notice get this Endpoint's immutable source identifier
  function getChainId() external view returns (uint16);

  // @notice the interface to retry failed message on this Endpoint destination
  // @param _srcChainId - the source chain identifier
  // @param _srcAddress - the source chain contract address
  // @param _payload - the payload to be retried
  function retryPayload(
    uint16 _srcChainId,
    bytes calldata _srcAddress,
    bytes calldata _payload
  ) external;

  // @notice query if any STORED payload (message blocking) at the endpoint.
  // @param _srcChainId - the source chain identifier
  // @param _srcAddress - the source chain contract address
  function hasStoredPayload(uint16 _srcChainId, bytes calldata _srcAddress)
    external
    view
    returns (bool);

  // @notice query if the _libraryAddress is valid for sending msgs.
  // @param _userApplication - the user app address on this EVM chain
  function getSendLibraryAddress(address _userApplication)
    external
    view
    returns (address);

  // @notice query if the _libraryAddress is valid for receiving msgs.
  // @param _userApplication - the user app address on this EVM chain
  function getReceiveLibraryAddress(address _userApplication)
    external
    view
    returns (address);

  // @notice query if the non-reentrancy guard for send() is on
  // @return true if the guard is on. false otherwise
  function isSendingPayload() external view returns (bool);

  // @notice query if the non-reentrancy guard for receive() is on
  // @return true if the guard is on. false otherwise
  function isReceivingPayload() external view returns (bool);

  // @notice get the configuration of the LayerZero messaging library of the specified version
  // @param _version - messaging library version
  // @param _chainId - the chainId for the pending config change
  // @param _userApplication - the contract address of the user application
  // @param _configType - type of configuration. every messaging library has its own convention.
  function getConfig(
    uint16 _version,
    uint16 _chainId,
    address _userApplication,
    uint256 _configType
  ) external view returns (bytes memory);

  // @notice get the send() LayerZero messaging library version
  // @param _userApplication - the contract address of the user application
  function getSendVersion(address _userApplication)
    external
    view
    returns (uint16);

  // @notice get the lzReceive() LayerZero messaging library version
  // @param _userApplication - the contract address of the user application
  function getReceiveVersion(address _userApplication)
    external
    view
    returns (uint16);
}

// SPDX-License-Identifier: MIT

pragma solidity >=0.5.0;

interface ILayerZeroReceiver {
  // @notice LayerZero endpoint will invoke this function to deliver the message on the destination
  // @param _srcChainId - the source endpoint identifier
  // @param _srcAddress - the source sending contract address from the source chain
  // @param _nonce - the ordered message nonce
  // @param _payload - the signed payload is the UA bytes has encoded to be sent
  function lzReceive(
    uint16 _srcChainId,
    bytes calldata _srcAddress,
    uint64 _nonce,
    bytes calldata _payload
  ) external;
}

// SPDX-License-Identifier: MIT

pragma solidity >=0.5.0;

interface ILayerZeroUserApplicationConfig {
  // @notice set the configuration of the LayerZero messaging library of the specified version
  // @param _version - messaging library version
  // @param _chainId - the chainId for the pending config change
  // @param _configType - type of configuration. every messaging library has its own convention.
  // @param _config - configuration in the bytes. can encode arbitrary content.
  function setConfig(
    uint16 _version,
    uint16 _chainId,
    uint256 _configType,
    bytes calldata _config
  ) external;

  // @notice set the send() LayerZero messaging library version to _version
  // @param _version - new messaging library version
  function setSendVersion(uint16 _version) external;

  // @notice set the lzReceive() LayerZero messaging library version to _version
  // @param _version - new messaging library version
  function setReceiveVersion(uint16 _version) external;

  // @notice Only when the UA needs to resume the message flow in blocking mode and clear the stored payload
  // @param _srcChainId - the chainId of the source chain
  // @param _srcAddress - the contract address of the source contract at the source chain
  function forceResumeReceive(uint16 _srcChainId, bytes calldata _srcAddress)
    external;
}

// SPDX-License-Identifier: BUSL-1.1

pragma solidity >=0.5.0;

interface IOFTReceiverV2 {
  /**
   * @dev Called by the OFT contract when tokens are received from source chain.
   * @param _srcChainId The chain id of the source chain.
   * @param _srcAddress The address of the OFT token contract on the source chain.
   * @param _nonce The nonce of the transaction on the source chain.
   * @param _from The address of the account who calls the sendAndCall() on the source chain.
   * @param _amount The amount of tokens to transfer.
   * @param _payload Additional data with no specified format.
   */
  function onOFTReceived(
    uint16 _srcChainId,
    bytes calldata _srcAddress,
    uint64 _nonce,
    bytes32 _from,
    uint256 _amount,
    bytes calldata _payload
  ) external;
}

// SPDX-License-Identifier: MIT

pragma solidity >=0.5.0;

import "./ICommonOFT.sol";

/**
 * @dev Interface of the IOFT core standard
 */
interface IOFTV2 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
   * `_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,
    uint256 _amount,
    LzCallParams calldata _callParams
  ) external payable;

  function sendAndCall(
    address _from,
    uint16 _dstChainId,
    bytes32 _toAddress,
    uint256 _amount,
    bytes calldata _payload,
    uint64 _dstGasForCall,
    LzCallParams calldata _callParams
  ) external payable;
}

// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

import "./Ownable.sol";
import "./ILayerZeroReceiver.sol";
import "./ILayerZeroUserApplicationConfig.sol";
import "./ILayerZeroEndpoint.sol";
import "./BytesLib.sol";

/*
 * a generic LzReceiver implementation
 */
abstract contract LzApp is
  Ownable,
  ILayerZeroReceiver,
  ILayerZeroUserApplicationConfig
{
  using BytesLib for bytes;

  // ua can not send payload larger than this by default, but it can be changed by the ua owner
  uint256 public constant DEFAULT_PAYLOAD_SIZE_LIMIT = 10000;

  ILayerZeroEndpoint public immutable lzEndpoint;
  mapping(uint16 => bytes) public trustedRemoteLookup;
  mapping(uint16 => mapping(uint16 => uint256)) public minDstGasLookup;
  mapping(uint16 => uint256) public payloadSizeLimitLookup;
  address public precrime;

  event SetPrecrime(address precrime);
  event SetTrustedRemote(uint16 _remoteChainId, bytes _path);
  event SetTrustedRemoteAddress(uint16 _remoteChainId, bytes _remoteAddress);
  event SetMinDstGas(uint16 _dstChainId, uint16 _type, uint256 _minDstGas);

  constructor(address _endpoint) {
    lzEndpoint = ILayerZeroEndpoint(_endpoint);
  }

  function lzReceive(
    uint16 _srcChainId,
    bytes calldata _srcAddress,
    uint64 _nonce,
    bytes calldata _payload
  ) public virtual override {
    // lzReceive must be called by the endpoint for security
    require(
      _msgSender() == address(lzEndpoint), "LzApp: invalid endpoint caller"
    );

    bytes memory trustedRemote = trustedRemoteLookup[_srcChainId];
    // if will still block the message pathway from (srcChainId, srcAddress). should not receive message from untrusted remote.
    require(
      _srcAddress.length == trustedRemote.length && trustedRemote.length > 0
        && keccak256(_srcAddress) == keccak256(trustedRemote),
      "LzApp: invalid source sending contract"
    );

    _blockingLzReceive(_srcChainId, _srcAddress, _nonce, _payload);
  }

  // abstract function - the default behaviour of LayerZero is blocking. See: NonblockingLzApp if you dont need to enforce ordered messaging
  function _blockingLzReceive(
    uint16 _srcChainId,
    bytes memory _srcAddress,
    uint64 _nonce,
    bytes memory _payload
  ) internal virtual;

  function _lzSend(
    uint16 _dstChainId,
    bytes memory _payload,
    address payable _refundAddress,
    address _zroPaymentAddress,
    bytes memory _adapterParams,
    uint256 _nativeFee
  ) internal virtual {
    bytes memory trustedRemote = trustedRemoteLookup[_dstChainId];
    require(
      trustedRemote.length != 0,
      "LzApp: destination chain is not a trusted source"
    );
    _checkPayloadSize(_dstChainId, _payload.length);
    lzEndpoint.send{value: _nativeFee}(
      _dstChainId,
      trustedRemote,
      _payload,
      _refundAddress,
      _zroPaymentAddress,
      _adapterParams
    );
  }

  function _checkGasLimit(
    uint16 _dstChainId,
    uint16 _type,
    bytes memory _adapterParams,
    uint256 _extraGas
  ) internal view virtual {
    uint256 providedGasLimit = _getGasLimit(_adapterParams);
    uint256 minGasLimit = minDstGasLookup[_dstChainId][_type] + _extraGas;
    require(minGasLimit > 0, "LzApp: minGasLimit not set");
    require(providedGasLimit >= minGasLimit, "LzApp: gas limit is too low");
  }

  function _getGasLimit(bytes memory _adapterParams)
    internal
    pure
    virtual
    returns (uint256 gasLimit)
  {
    require(_adapterParams.length >= 34, "LzApp: invalid adapterParams");
    assembly {
      gasLimit := mload(add(_adapterParams, 34))
    }
  }

  function _checkPayloadSize(uint16 _dstChainId, uint256 _payloadSize)
    internal
    view
    virtual
  {
    uint256 payloadSizeLimit = payloadSizeLimitLookup[_dstChainId];
    if (payloadSizeLimit == 0) {
      // use default if not set
      payloadSizeLimit = DEFAULT_PAYLOAD_SIZE_LIMIT;
    }
    require(
      _payloadSize <= payloadSizeLimit, "LzApp: payload size is too large"
    );
  }

  //---------------------------UserApplication config----------------------------------------
  function getConfig(
    uint16 _version,
    uint16 _chainId,
    address,
    uint256 _configType
  ) external view returns (bytes memory) {
    return lzEndpoint.getConfig(_version, _chainId, address(this), _configType);
  }

  // generic config for LayerZero user Application
  function setConfig(
    uint16 _version,
    uint16 _chainId,
    uint256 _configType,
    bytes calldata _config
  ) external override onlyOwner {
    lzEndpoint.setConfig(_version, _chainId, _configType, _config);
  }

  function setSendVersion(uint16 _version) external override onlyOwner {
    lzEndpoint.setSendVersion(_version);
  }

  function setReceiveVersion(uint16 _version) external override onlyOwner {
    lzEndpoint.setReceiveVersion(_version);
  }

  function forceResumeReceive(uint16 _srcChainId, bytes calldata _srcAddress)
    external
    override
    onlyOwner
  {
    lzEndpoint.forceResumeReceive(_srcChainId, _srcAddress);
  }

  // _path = abi.encodePacked(remoteAddress, localAddress)
  // this function set the trusted path for the cross-chain communication
  function setTrustedRemote(uint16 _remoteChainId, bytes calldata _path)
    external
    onlyOwner
  {
    trustedRemoteLookup[_remoteChainId] = _path;
    emit SetTrustedRemote(_remoteChainId, _path);
  }

  function setTrustedRemoteAddress(
    uint16 _remoteChainId,
    bytes calldata _remoteAddress
  ) external onlyOwner {
    trustedRemoteLookup[_remoteChainId] =
      abi.encodePacked(_remoteAddress, address(this));
    emit SetTrustedRemoteAddress(_remoteChainId, _remoteAddress);
  }

  function getTrustedRemoteAddress(uint16 _remoteChainId)
    external
    view
    returns (bytes memory)
  {
    bytes memory path = trustedRemoteLookup[_remoteChainId];
    require(path.length != 0, "LzApp: no trusted path record");
    return path.slice(0, path.length - 20); // the last 20 bytes should be address(this)
  }

  function setPrecrime(address _precrime) external onlyOwner {
    precrime = _precrime;
    emit SetPrecrime(_precrime);
  }

  function setMinDstGas(uint16 _dstChainId, uint16 _packetType, uint256 _minGas)
    external
    onlyOwner
  {
    require(_minGas > 0, "LzApp: invalid minGas");
    minDstGasLookup[_dstChainId][_packetType] = _minGas;
    emit SetMinDstGas(_dstChainId, _packetType, _minGas);
  }

  // if the size is 0, it means default size limit
  function setPayloadSizeLimit(uint16 _dstChainId, uint256 _size)
    external
    onlyOwner
  {
    payloadSizeLimitLookup[_dstChainId] = _size;
  }

  //--------------------------- VIEW FUNCTION ----------------------------------------
  function isTrustedRemote(uint16 _srcChainId, bytes calldata _srcAddress)
    external
    view
    returns (bool)
  {
    bytes memory trustedSource = trustedRemoteLookup[_srcChainId];
    return keccak256(trustedSource) == keccak256(_srcAddress);
  }
}

// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

import "./LzApp.sol";
import "./ExcessivelySafeCall.sol";

/*
 * the default LayerZero messaging behaviour is blocking, i.e. any failed message will block the channel
 * this abstract class try-catch all fail messages and store locally for future retry. hence, non-blocking
 * NOTE: if the srcAddress is not configured properly, it will still block the message pathway from (srcChainId, srcAddress)
 */
abstract contract NonblockingLzApp is LzApp {
  using ExcessivelySafeCall for address;

  constructor(address _endpoint) LzApp(_endpoint) {}

  mapping(uint16 => mapping(bytes => mapping(uint64 => bytes32))) public
    failedMessages;

  event MessageFailed(
    uint16 _srcChainId,
    bytes _srcAddress,
    uint64 _nonce,
    bytes _payload,
    bytes _reason
  );
  event RetryMessageSuccess(
    uint16 _srcChainId, bytes _srcAddress, uint64 _nonce, bytes32 _payloadHash
  );

  // overriding the virtual function in LzReceiver
  function _blockingLzReceive(
    uint16 _srcChainId,
    bytes memory _srcAddress,
    uint64 _nonce,
    bytes memory _payload
  ) internal virtual override {
    (bool success, bytes memory reason) = address(this).excessivelySafeCall(
      gasleft(),
      150,
      abi.encodeWithSelector(
        this.nonblockingLzReceive.selector,
        _srcChainId,
        _srcAddress,
        _nonce,
        _payload
      )
    );
    // try-catch all errors/exceptions
    if (!success) {
      _storeFailedMessage(_srcChainId, _srcAddress, _nonce, _payload, reason);
    }
  }

  function _storeFailedMessage(
    uint16 _srcChainId,
    bytes memory _srcAddress,
    uint64 _nonce,
    bytes memory _payload,
    bytes memory _reason
  ) internal virtual {
    failedMessages[_srcChainId][_srcAddress][_nonce] = keccak256(_payload);
    emit MessageFailed(_srcChainId, _srcAddress, _nonce, _payload, _reason);
  }

  function nonblockingLzReceive(
    uint16 _srcChainId,
    bytes calldata _srcAddress,
    uint64 _nonce,
    bytes calldata _payload
  ) public virtual {
    // only internal transaction
    require(
      _msgSender() == address(this), "NonblockingLzApp: caller must be LzApp"
    );
    _nonblockingLzReceive(_srcChainId, _srcAddress, _nonce, _payload);
  }

  //@notice override this function
  function _nonblockingLzReceive(
    uint16 _srcChainId,
    bytes memory _srcAddress,
    uint64 _nonce,
    bytes memory _payload
  ) internal virtual;

  function retryMessage(
    uint16 _srcChainId,
    bytes calldata _srcAddress,
    uint64 _nonce,
    bytes calldata _payload
  ) public payable virtual {
    // assert there is message to retry
    bytes32 payloadHash = failedMessages[_srcChainId][_srcAddress][_nonce];
    require(payloadHash != bytes32(0), "NonblockingLzApp: no stored message");
    require(
      keccak256(_payload) == payloadHash, "NonblockingLzApp: invalid payload"
    );
    // clear the stored message
    failedMessages[_srcChainId][_srcAddress][_nonce] = bytes32(0);
    // execute the message. revert if it fails again
    _nonblockingLzReceive(_srcChainId, _srcAddress, _nonce, _payload);
    emit RetryMessageSuccess(_srcChainId, _srcAddress, _nonce, payloadHash);
  }
}

// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

import "./NonblockingLzApp.sol";
import "./ExcessivelySafeCall.sol";
import "./ICommonOFT.sol";
import "./IOFTReceiverV2.sol";

abstract contract OFTCoreV2 is NonblockingLzApp {
  using BytesLib for bytes;
  using ExcessivelySafeCall for address;

  uint256 public constant NO_EXTRA_GAS = 0;

  // packet type
  uint8 public constant PT_SEND = 0;
  uint8 public constant PT_SEND_AND_CALL = 1;

  uint8 public immutable sharedDecimals;

  bool public useCustomAdapterParams;
  mapping(uint16 => mapping(bytes => mapping(uint64 => bool))) public
    creditedPackets;

  /**
   * @dev Emitted when `_amount` tokens are moved from the `_sender` to (`_dstChainId`, `_toAddress`)
   * `_nonce` is the outbound nonce
   */
  event SendToChain(
    uint16 indexed _dstChainId,
    address indexed _from,
    bytes32 indexed _toAddress,
    uint256 _amount
  );

  /**
   * @dev Emitted when `_amount` tokens are received from `_srcChainId` into the `_toAddress` on the local chain.
   * `_nonce` is the inbound nonce.
   */
  event ReceiveFromChain(
    uint16 indexed _srcChainId, address indexed _to, uint256 _amount
  );

  event SetUseCustomAdapterParams(bool _useCustomAdapterParams);

  event CallOFTReceivedSuccess(
    uint16 indexed _srcChainId, bytes _srcAddress, uint64 _nonce, bytes32 _hash
  );

  event NonContractAddress(address _address);

  // _sharedDecimals should be the minimum decimals on all chains
  constructor(uint8 _sharedDecimals, address _lzEndpoint)
    NonblockingLzApp(_lzEndpoint)
  {
    sharedDecimals = _sharedDecimals;
  }

  /**
   *
   * public functions
   *
   */
  function callOnOFTReceived(
    uint16 _srcChainId,
    bytes calldata _srcAddress,
    uint64 _nonce,
    bytes32 _from,
    address _to,
    uint256 _amount,
    bytes calldata _payload,
    uint256 _gasForCall
  ) public virtual {
    require(_msgSender() == address(this), "OFTCore: caller must be OFTCore");

    // send
    _amount = _transferFrom(address(this), _to, _amount);
    emit ReceiveFromChain(_srcChainId, _to, _amount);

    // call
    IOFTReceiverV2(_to).onOFTReceived{gas: _gasForCall}(
      _srcChainId, _srcAddress, _nonce, _from, _amount, _payload
    );
  }

  function setUseCustomAdapterParams(bool _useCustomAdapterParams)
    public
    virtual
    onlyOwner
  {
    useCustomAdapterParams = _useCustomAdapterParams;
    emit SetUseCustomAdapterParams(_useCustomAdapterParams);
  }

  /**
   *
   * internal functions
   *
   */
  function _estimateSendFee(
    uint16 _dstChainId,
    bytes32 _toAddress,
    uint256 _amount,
    bool _useZro,
    bytes memory _adapterParams
  ) internal view virtual returns (uint256 nativeFee, uint256 zroFee) {
    // mock the payload for sendFrom()
    bytes memory payload = _encodeSendPayload(_toAddress, _ld2sd(_amount));
    return lzEndpoint.estimateFees(
      _dstChainId, address(this), payload, _useZro, _adapterParams
    );
  }

  function _estimateSendAndCallFee(
    uint16 _dstChainId,
    bytes32 _toAddress,
    uint256 _amount,
    bytes memory _payload,
    uint64 _dstGasForCall,
    bool _useZro,
    bytes memory _adapterParams
  ) internal view virtual returns (uint256 nativeFee, uint256 zroFee) {
    // mock the payload for sendAndCall()
    bytes memory payload = _encodeSendAndCallPayload(
      msg.sender, _toAddress, _ld2sd(_amount), _payload, _dstGasForCall
    );
    return lzEndpoint.estimateFees(
      _dstChainId, address(this), payload, _useZro, _adapterParams
    );
  }

  function _nonblockingLzReceive(
    uint16 _srcChainId,
    bytes memory _srcAddress,
    uint64 _nonce,
    bytes memory _payload
  ) internal virtual override {
    uint8 packetType = _payload.toUint8(0);

    if (packetType == PT_SEND) {
      _sendAck(_srcChainId, _srcAddress, _nonce, _payload);
    } else if (packetType == PT_SEND_AND_CALL) {
      _sendAndCallAck(_srcChainId, _srcAddress, _nonce, _payload);
    } else {
      revert("OFTCore: unknown packet type");
    }
  }

  function _send(
    address _from,
    uint16 _dstChainId,
    bytes32 _toAddress,
    uint256 _amount,
    address payable _refundAddress,
    address _zroPaymentAddress,
    bytes memory _adapterParams
  ) internal virtual returns (uint256 amount) {
    _checkAdapterParams(_dstChainId, PT_SEND, _adapterParams, NO_EXTRA_GAS);

    (amount,) = _removeDust(_amount);
    amount = _debitFrom(_from, _dstChainId, _toAddress, amount); // amount returned should not have dust
    require(amount > 0, "OFTCore: amount too small");

    bytes memory lzPayload = _encodeSendPayload(_toAddress, _ld2sd(amount));
    _lzSend(
      _dstChainId,
      lzPayload,
      _refundAddress,
      _zroPaymentAddress,
      _adapterParams,
      msg.value
    );

    emit SendToChain(_dstChainId, _from, _toAddress, amount);
  }

  function _sendAck(
    uint16 _srcChainId,
    bytes memory,
    uint64,
    bytes memory _payload
  ) internal virtual {
    (address to, uint64 amountSD) = _decodeSendPayload(_payload);
    if (to == address(0)) {
      to = address(0xdead);
    }

    uint256 amount = _sd2ld(amountSD);
    amount = _creditTo(_srcChainId, to, amount);

    emit ReceiveFromChain(_srcChainId, to, amount);
  }

  function _sendAndCall(
    address _from,
    uint16 _dstChainId,
    bytes32 _toAddress,
    uint256 _amount,
    bytes memory _payload,
    uint64 _dstGasForCall,
    address payable _refundAddress,
    address _zroPaymentAddress,
    bytes memory _adapterParams
  ) internal virtual returns (uint256 amount) {
    _checkAdapterParams(
      _dstChainId, PT_SEND_AND_CALL, _adapterParams, _dstGasForCall
    );

    (amount,) = _removeDust(_amount);
    amount = _debitFrom(_from, _dstChainId, _toAddress, amount);
    require(amount > 0, "OFTCore: amount too small");

    // encode the msg.sender into the payload instead of _from
    bytes memory lzPayload = _encodeSendAndCallPayload(
      msg.sender, _toAddress, _ld2sd(amount), _payload, _dstGasForCall
    );
    _lzSend(
      _dstChainId,
      lzPayload,
      _refundAddress,
      _zroPaymentAddress,
      _adapterParams,
      msg.value
    );

    emit SendToChain(_dstChainId, _from, _toAddress, amount);
  }

  function _sendAndCallAck(
    uint16 _srcChainId,
    bytes memory _srcAddress,
    uint64 _nonce,
    bytes memory _payload
  ) internal virtual {
    (
      bytes32 from,
      address to,
      uint64 amountSD,
      bytes memory payloadForCall,
      uint64 gasForCall
    ) = _decodeSendAndCallPayload(_payload);

    bool credited = creditedPackets[_srcChainId][_srcAddress][_nonce];
    uint256 amount = _sd2ld(amountSD);

    // credit to this contract first, and then transfer to receiver only if callOnOFTReceived() succeeds
    if (!credited) {
      amount = _creditTo(_srcChainId, address(this), amount);
      creditedPackets[_srcChainId][_srcAddress][_nonce] = true;
    }

    if (!_isContract(to)) {
      emit NonContractAddress(to);
      return;
    }

    // workaround for stack too deep
    uint16 srcChainId = _srcChainId;
    bytes memory srcAddress = _srcAddress;
    uint64 nonce = _nonce;
    bytes memory payload = _payload;
    bytes32 from_ = from;
    address to_ = to;
    uint256 amount_ = amount;
    bytes memory payloadForCall_ = payloadForCall;

    // no gas limit for the call if retry
    uint256 gas = credited ? gasleft() : gasForCall;
    (bool success, bytes memory reason) = address(this).excessivelySafeCall(
      gasleft(),
      150,
      abi.encodeWithSelector(
        this.callOnOFTReceived.selector,
        srcChainId,
        srcAddress,
        nonce,
        from_,
        to_,
        amount_,
        payloadForCall_,
        gas
      )
    );

    if (success) {
      bytes32 hash = keccak256(payload);
      emit CallOFTReceivedSuccess(srcChainId, srcAddress, nonce, hash);
    } else {
      // store the failed message into the nonblockingLzApp
      _storeFailedMessage(srcChainId, srcAddress, nonce, payload, reason);
    }
  }

  function _isContract(address _account) internal view returns (bool) {
    return _account.code.length > 0;
  }

  function _checkAdapterParams(
    uint16 _dstChainId,
    uint16 _pkType,
    bytes memory _adapterParams,
    uint256 _extraGas
  ) internal virtual {
    if (useCustomAdapterParams) {
      _checkGasLimit(_dstChainId, _pkType, _adapterParams, _extraGas);
    } else {
      require(
        _adapterParams.length == 0, "OFTCore: _adapterParams must be empty."
      );
    }
  }

  function _ld2sd(uint256 _amount) internal view virtual returns (uint64) {
    uint256 amountSD = _amount / _ld2sdRate();
    require(amountSD <= type(uint64).max, "OFTCore: amountSD overflow");
    return uint64(amountSD);
  }

  function _sd2ld(uint64 _amountSD) internal view virtual returns (uint256) {
    return _amountSD * _ld2sdRate();
  }

  function _removeDust(uint256 _amount)
    internal
    view
    virtual
    returns (uint256 amountAfter, uint256 dust)
  {
    dust = _amount % _ld2sdRate();
    amountAfter = _amount - dust;
  }

  function _encodeSendPayload(bytes32 _toAddress, uint64 _amountSD)
    internal
    view
    virtual
    returns (bytes memory)
  {
    return abi.encodePacked(PT_SEND, _toAddress, _amountSD);
  }

  function _decodeSendPayload(bytes memory _payload)
    internal
    view
    virtual
    returns (address to, uint64 amountSD)
  {
    require(
      _payload.toUint8(0) == PT_SEND && _payload.length == 41,
      "OFTCore: invalid payload"
    );

    to = _payload.toAddress(13); // drop the first 12 bytes of bytes32
    amountSD = _payload.toUint64(33);
  }

  function _encodeSendAndCallPayload(
    address _from,
    bytes32 _toAddress,
    uint64 _amountSD,
    bytes memory _payload,
    uint64 _dstGasForCall
  ) internal view virtual returns (bytes memory) {
    return abi.encodePacked(
      PT_SEND_AND_CALL,
      _toAddress,
      _amountSD,
      _addressToBytes32(_from),
      _dstGasForCall,
      _payload
    );
  }

  function _decodeSendAndCallPayload(bytes memory _payload)
    internal
    view
    virtual
    returns (
      bytes32 from,
      address to,
      uint64 amountSD,
      bytes memory payload,
      uint64 dstGasForCall
    )
  {
    require(_payload.toUint8(0) == PT_SEND_AND_CALL, "OFTCore: invalid payload");

    to = _payload.toAddress(13); // drop the first 12 bytes of bytes32
    amountSD = _payload.toUint64(33);
    from = _payload.toBytes32(41);
    dstGasForCall = _payload.toUint64(73);
    payload = _payload.slice(81, _payload.length - 81);
  }

  function _addressToBytes32(address _address)
    internal
    pure
    virtual
    returns (bytes32)
  {
    return bytes32(uint256(uint160(_address)));
  }

  function _debitFrom(
    address _from,
    uint16 _dstChainId,
    bytes32 _toAddress,
    uint256 _amount
  ) internal virtual returns (uint256);

  function _creditTo(uint16 _srcChainId, address _toAddress, uint256 _amount)
    internal
    virtual
    returns (uint256);

  function _transferFrom(address _from, address _to, uint256 _amount)
    internal
    virtual
    returns (uint256);

  function _ld2sdRate() internal view virtual returns (uint256);
}

// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

import "./ERC20.sol";
import "./BaseOFTV2.sol";

contract OFTV2 is BaseOFTV2, ERC20 {
  uint256 internal immutable ld2sdRate;

  constructor(
    string memory _name,
    string memory _symbol,
    uint8 _sharedDecimals,
    address _lzEndpoint
  ) ERC20(_name, _symbol) BaseOFTV2(_sharedDecimals, _lzEndpoint) {
    uint8 decimals = decimals();
    require(
      _sharedDecimals <= decimals, "OFT: sharedDecimals must be <= decimals"
    );
    ld2sdRate = 10 ** (decimals - _sharedDecimals);
  }

  /**
   *
   * public functions
   *
   */
  function circulatingSupply() public view virtual override returns (uint256) {
    return totalSupply();
  }

  function token() public view virtual override returns (address) {
    return address(this);
  }

  /**
   *
   * internal functions
   *
   */
  function _debitFrom(address _from, uint16, bytes32, uint256 _amount)
    internal
    virtual
    override
    returns (uint256)
  {
    address spender = _msgSender();
    if (_from != spender) _spendAllowance(_from, spender, _amount);
    _burn(_from, _amount);
    return _amount;
  }

  function _creditTo(uint16, address _toAddress, uint256 _amount)
    internal
    virtual
    override
    returns (uint256)
  {
    _mint(_toAddress, _amount);
    return _amount;
  }

  function _transferFrom(address _from, address _to, uint256 _amount)
    internal
    virtual
    override
    returns (uint256)
  {
    address spender = _msgSender();
    // if transfer from this contract, no need to check allowance
    if (_from != address(this) && _from != spender) {
      _spendAllowance(_from, spender, _amount);
    }
    _transfer(_from, _to, _amount);
    return _amount;
  }

  function _ld2sdRate() internal view virtual override returns (uint256) {
    return ld2sdRate;
  }
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.7.0) (access/Ownable.sol)

pragma solidity ^0.8.0;

import "./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
//   _   _ __  ____  __
//  | | | |  \/  \ \/ /
//  | |_| | |\/| |\  /
//  |  _  | |  | |/  \
//  |_| |_|_|  |_/_/\_\
pragma solidity 0.8.18;

import {OFTV2} from "./OFTV2.sol";

contract RemoteHMX is OFTV2 {
  constructor(address _layerZeroEndpoint, uint8 _sharedDecimals)
    OFTV2("HMX", "HMX", _sharedDecimals, _layerZeroEndpoint)
  {}
}

{
  "compilationTarget": {
    "RemoteHMX.sol": "RemoteHMX"
  },
  "evmVersion": "paris",
  "libraries": {},
  "metadata": {
    "bytecodeHash": "ipfs"
  },
  "optimizer": {
    "enabled": true,
    "runs": 1
  },
  "remappings": []
}