// SPDX-License-Identifier: UNLICENSED

pragma solidity =0.8.18;

import "./IGuardable.sol";

library GuardHelper {
    // 00000000(192 0's repeated)111(64times)
    // (64 default on, 192 default off)
    bytes32 internal constant DEFAULT_PRIVILEGES = bytes32(uint256(2 ** 64 - 1));

    function requiredPrivileges(address account) internal view returns (bytes32 privileges) {
        // call to account with no code returns true
        // call to account with code and no function returns false
        // call to account with code and function returns true
        (bool success, bytes memory returndata) =
            account.staticcall(abi.encodePacked(IGuardable.requiredPrivileges.selector));
        privileges = (success && (account.code.length > 0)) ? bytes32(returndata) : DEFAULT_PRIVILEGES;
    }

    function check(bytes32 privileges, bytes32 query) internal pure returns (bool) {
        return privileges & query == query;
    }

    function mergePrivileges(bytes32 privileges1, bytes32 privileges2) internal pure returns (bytes32) {
        return privileges1 | privileges2;
    }

    function mergePrivileges(bytes32 privileges1, bytes32 privileges2, bytes32 privileges3)
        internal
        pure
        returns (bytes32)
    {
        return privileges1 | privileges2 | privileges3;
    }

    function switchOn(uint256[] memory ids, bytes32 base) internal pure returns (bytes32 result) {
        result = base;
        for (uint256 i; i < ids.length; ++i) {
            result = result | bytes32(2 ** ids[i]);
        }
    }

    function switchOff(uint256[] memory ids, bytes32 base) internal pure returns (bytes32 result) {
        result = base;
        for (uint256 i; i < ids.length; ++i) {
            result = result & bytes32(type(uint256).max - 2 ** ids[i]);
        }
    }
}