// SPDX-License-Identifier: MIT
pragma solidity 0.6.12;

import "./IERC20.sol";


pragma experimental ABIEncoderV2;
// solhint-disable avoid-low-level-calls
// T1 - T4: OK
contract BaseBoringBatchable {
    function _getRevertMsg(bytes memory _returnData) internal pure returns (string memory) {
        // If the _res length is less than 68, then the transaction failed silently (without a revert message)
        if (_returnData.length < 68) return "Transaction reverted silently";
        assembly {
            // Slice the sighash.
            _returnData := add(_returnData, 0x04)
        }
        return abi.decode(_returnData, (string)); // All that remains is the revert string
    }    
    
    // F3 - F9: OK
    // F1: External is ok here because this is the batch function, adding it to a batch makes no sense
    // F2: Calls in the batch may be payable, delegatecall operates in the same context, so each call in the batch has access to msg.value
    // C1 - C21: OK
    // C3: The length of the loop is fully under user control, so can't be exploited
    // C7: Delegatecall is only used on the same contract, so it's safe
    function batch(bytes[] calldata calls, bool revertOnFail) external payable returns(bool[] memory successes, bytes[] memory results) {
        // Interactions
        successes = new bool[](calls.length);
        results = new bytes[](calls.length);
        for (uint256 i = 0; i < calls.length; i++) {
            (bool success, bytes memory result) = address(this).delegatecall(calls[i]);
            require(success || !revertOnFail, _getRevertMsg(result));
            successes[i] = success;
            results[i] = result;
        }
    }
}
contract BoringBatchable is BaseBoringBatchable {
    // F1 - F9: OK
    // F6: Parameters can be used front-run the permit and the user's permit will fail (due to nonce or other revert)
    //     if part of a batch this could be used to grief once as the second call would not need the permit
    // C1 - C21: OK
    function permitToken(IERC20 token, address from, address to, uint256 amount, uint256 deadline, uint8 v, bytes32 r, bytes32 s) public {
        // Interactions
        // X1 - X5
        token.permit(from, to, amount, deadline, v, r, s);
    }
}