Gas Manager

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.24;

import "@hanzo/gas/IHanzoPaymaster.sol";
import "@account-abstraction/contracts/core/BasePaymaster.sol";

contract HanzoPaymaster is BasePaymaster {
    mapping(address => bool) public whitelistedContracts;
    mapping(address => uint256) public userGasUsed;
    uint256 public maxGasPerUser = 0.01 ether;

    constructor(IEntryPoint _entryPoint) BasePaymaster(_entryPoint) {}

    // Validate paymaster will sponsor this UserOp
    function _validatePaymasterUserOp(
        UserOperation calldata userOp,
        bytes32 userOpHash,
        uint256 maxCost
    ) internal override returns (bytes memory context, uint256 validationData) {
        address target = address(bytes20(userOp.callData[16:36]));
        require(whitelistedContracts[target], "Contract not whitelisted");
        require(
            userGasUsed[userOp.sender] + maxCost <= maxGasPerUser,
            "User gas limit exceeded"
        );

        return (abi.encode(userOp.sender, maxCost), 0);
    }

    // Called after UserOp execution
    function _postOp(
        PostOpMode mode,
        bytes calldata context,
        uint256 actualGasCost
    ) internal override {
        (address user, ) = abi.decode(context, (address, uint256));
        userGasUsed[user] += actualGasCost;
    }

    // Admin functions
    function whitelistContract(address target, bool allowed) external onlyOwner {
        whitelistedContracts[target] = allowed;
    }

    function setMaxGasPerUser(uint256 _max) external onlyOwner {
        maxGasPerUser = _max;
    }
}