library Utils {
    /// @notice Returns lesser of two values
    function minU32(uint32 a, uint32 b) internal pure returns (uint32) {
        return a < b ? a : b;
    }

    /// @notice Returns lesser of two values
    function minU64(uint64 a, uint64 b) internal pure returns (uint64) {
        return a < b ? a : b;
    }

    /// @notice Sends tokens
    /// @dev NOTE: this function handles tokens that have transfer function not strictly compatible with ERC20 standard
    /// @dev NOTE: call `transfer` to this token may return (bool) or nothing
    /// @param _token Token address
    /// @param _to Address of recipient
    /// @param _amount Amount of tokens to transfer
    /// @return bool flag indicating that transfer is successful
    function sendERC20(
        IERC20 _token,
        address _to,
        uint256 _amount
    ) internal returns (bool) {
        (bool callSuccess, bytes memory callReturnValueEncoded) = address(_token).call(
            abi.encodeWithSignature("transfer(address,uint256)", _to, _amount)
        );
        // `transfer` method may return (bool) or nothing.
        bool returnedSuccess = callReturnValueEncoded.length == 0 || abi.decode(callReturnValueEncoded, (bool));
        return callSuccess && returnedSuccess;
    }

    /// @notice Transfers token from one address to another
    /// @dev NOTE: this function handles tokens that have transfer function not strictly compatible with ERC20 standard
    /// @dev NOTE: call `transferFrom` to this token may return (bool) or nothing
    /// @param _token Token address
    /// @param _from Address of sender
    /// @param _to Address of recipient
    /// @param _amount Amount of tokens to transfer
    /// @return bool flag indicating that transfer is successful
    function transferFromERC20(
        IERC20 _token,
        address _from,
        address _to,
        uint256 _amount
    ) internal returns (bool) {
        (bool callSuccess, bytes memory callReturnValueEncoded) = address(_token).call(
            abi.encodeWithSignature("transferFrom(address,address,uint256)", _from, _to, _amount)
        );
        // `transferFrom` method may return (bool) or nothing.
        bool returnedSuccess = callReturnValueEncoded.length == 0 || abi.decode(callReturnValueEncoded, (bool));
        return callSuccess && returnedSuccess;
    }

    /// @notice Recovers signer's address from ethereum signature for given message
    /// @param _signature 65 bytes concatenated. R (32) + S (32) + V (1)
    /// @param _messageHash signed message hash.
    /// @return address of the signer
    function recoverAddressFromEthSignature(bytes memory _signature, bytes32 _messageHash)
        internal
        pure
        returns (address)
    {
        require(_signature.length == 65, "P"); // incorrect signature length

        bytes32 signR;
        bytes32 signS;
        uint8 signV;
        assembly {
            signR := mload(add(_signature, 32))
            signS := mload(add(_signature, 64))
            signV := byte(0, mload(add(_signature, 96)))
        }

        return ecrecover(_messageHash, signV, signR, signS);
    }

    /// @notice Returns new_hash = hash(old_hash + bytes)
    function concatHash(bytes32 _hash, bytes memory _bytes) internal pure returns (bytes32) {
        bytes32 result;
        assembly {
            let bytesLen := add(mload(_bytes), 32)
            mstore(_bytes, _hash)
            result := keccak256(_bytes, bytesLen)
        }
        return result;
    }

    function hashBytesToBytes20(bytes memory _bytes) internal pure returns (bytes20) {
        return bytes20(uint160(uint256(keccak256(_bytes))));
    }
}
function minU64(uint64 a, uint64 b) internal pure returns (uint64) {
    return a < b ? a : b;
}

/// @notice Returns lesser of two values