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

struct MultiCall {
    address target;
    bytes callData;
}

library MultiCallOps {
    function copyMulticall(MultiCall memory call)
        internal
        pure
        returns (MultiCall memory)
    {
        return MultiCall({ target: call.target, callData: call.callData });
    }

    function trim(MultiCall[] memory calls)
        internal
        pure
        returns (MultiCall[] memory trimmed)
    {
        uint256 len = calls.length;

        if (len == 0) return calls;

        uint256 foundLen;
        while (calls[foundLen].target != address(0)) {
            unchecked {
                ++foundLen;
                if (foundLen == len) return calls;
            }
        }

        if (foundLen > 0) return copy(calls, foundLen);
    }

    function copy(MultiCall[] memory calls, uint256 len)
        internal
        pure
        returns (MultiCall[] memory res)
    {
        res = new MultiCall[](len);
        for (uint256 i; i < len; ) {
            res[i] = copyMulticall(calls[i]);
            unchecked {
                ++i;
            }
        }
    }

    function clone(MultiCall[] memory calls)
        internal
        pure
        returns (MultiCall[] memory res)
    {
        return copy(calls, calls.length);
    }

    function append(MultiCall[] memory calls, MultiCall memory newCall)
        internal
        pure
        returns (MultiCall[] memory res)
    {
        uint256 len = calls.length;
        res = new MultiCall[](len + 1);
        for (uint256 i; i < len; ) {
            res[i] = copyMulticall(calls[i]);
            unchecked {
                ++i;
            }
        }
        res[len] = copyMulticall(newCall);
    }

    function prepend(MultiCall[] memory calls, MultiCall memory newCall)
        internal
        pure
        returns (MultiCall[] memory res)
    {
        uint256 len = calls.length;
        res = new MultiCall[](len + 1);
        res[0] = copyMulticall(newCall);

        for (uint256 i = 1; i < len + 1; ) {
            res[i] = copyMulticall(calls[i]);
            unchecked {
                ++i;
            }
        }
    }

    function concat(MultiCall[] memory calls1, MultiCall[] memory calls2)
        internal
        pure
        returns (MultiCall[] memory res)
    {
        uint256 len1 = calls1.length;
        uint256 lenTotal = len1 + calls2.length;

        if (lenTotal == calls1.length) return clone(calls1);
        if (lenTotal == calls2.length) return clone(calls2);

        res = new MultiCall[](lenTotal);

        for (uint256 i; i < lenTotal; ) {
            res[i] = (i < len1)
                ? copyMulticall(calls1[i])
                : copyMulticall(calls2[i - len1]);
            unchecked {
                ++i;
            }
        }
    }
}