// SPDX-License-Identifier: MIT
pragma solidity 0.8.10;

/**
 * @dev All credits to boring crypto https://github.com/boringcrypto/BoringSolidity/blob/master/contracts/libraries/BoringERC20.sol
 */
library IntERC20 {
    bytes4 private constant SIG_DECIMALS = 0x313ce567; // decimals()
    bytes4 private constant SIG_SYMBOL = 0x95d89b41; // symbol()

    function returnDataToString(bytes memory data)
        internal
        pure
        returns (string memory)
    {
        if (data.length >= 64) {
            return abi.decode(data, (string));
        } else if (data.length == 32) {
            uint8 i = 0;
            while (i < 32 && data[i] != 0) {
                i++;
            }
            bytes memory bytesArray = new bytes(i);
            for (i = 0; i < 32 && data[i] != 0; i++) {
                bytesArray[i] = data[i];
            }
            return string(bytesArray);
        } else {
            return "???";
        }
    }

    /// @notice Provides a safe ERC20.symbol version which returns '???' as fallback string.
    /// @param token The address of the ERC-20 token contract.
    /// @return (string) Token symbol.
    function safeSymbol(address token) internal view returns (string memory) {
        require(isContract(token), "IntERC20: not a contract");

        (bool success, bytes memory data) = token.staticcall(
            abi.encodeWithSelector(SIG_SYMBOL)
        );
        return success ? returnDataToString(data) : "???";
    }

    /// @notice Provides a safe ERC20.decimals version which returns '18' as fallback value.
    /// @param token The address of the ERC-20 token contract.
    /// @return (uint8) Token decimals.
    function safeDecimals(address token) internal view returns (uint8) {
        require(isContract(token), "IntERC20: not a contract");

        (bool success, bytes memory data) = token.staticcall(
            abi.encodeWithSelector(SIG_DECIMALS)
        );
        return success && data.length == 32 ? abi.decode(data, (uint8)) : 18;
    }

    function isPair(address token) internal view returns (bool result) {
        return
            keccak256(abi.encodePacked(safeSymbol(token))) ==
            keccak256("Cake-LP");
    }

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