TreasuryDropper

[
  {
    "inputs": [
      {
        "internalType": "address",
        "name": "token_",
        "type": "address"
      },
      {
        "internalType": "address",
        "name": "owner_",
        "type": "address"
      },
      {
        "internalType": "address",
        "name": "operator_",
        "type": "address"
      },
      {
        "internalType": "uint256",
        "name": "maxDrop_",
        "type": "uint256"
      }
    ],
    "stateMutability": "nonpayable",
    "type": "constructor"
  },
  {
    "inputs": [
      {
        "internalType": "bytes32",
        "name": "claimId",
        "type": "bytes32"
      }
    ],
    "name": "AlreadyClaimed",
    "type": "error"
  },
  {
    "inputs": [],
    "name": "EnforcedPause",
    "type": "error"
  },
  {
    "inputs": [],
    "name": "ExpectedPause",
    "type": "error"
  },
  {
    "inputs": [],
    "name": "InvalidAmount",
    "type": "error"
  },
  {
    "inputs": [],
    "name": "NotOperator",
    "type": "error"
  },
  {
    "inputs": [
      {
        "internalType": "address",
        "name": "owner",
        "type": "address"
      }
    ],
    "name": "OwnableInvalidOwner",
    "type": "error"
  },
  {
    "inputs": [
      {
        "internalType": "address",
        "name": "account",
        "type": "address"
      }
    ],
    "name": "OwnableUnauthorizedAccount",
    "type": "error"
  },
  {
    "inputs": [
      {
        "internalType": "address",
        "name": "token",
        "type": "address"
      }
    ],
    "name": "SafeERC20FailedOperation",
    "type": "error"
  },
  {
    "inputs": [],
    "name": "ZeroAddress",
    "type": "error"
  },
  {
    "anonymous": false,
    "inputs": [
      {
        "indexed": true,
        "internalType": "bytes32",
        "name": "claimId",
        "type": "bytes32"
      },
      {
        "indexed": true,
        "internalType": "address",
        "name": "to",
        "type": "address"
      },
      {
        "indexed": false,
        "internalType": "uint256",
        "name": "amount",
        "type": "uint256"
      }
    ],
    "name": "Dropped",
    "type": "event"
  },
  {
    "anonymous": false,
    "inputs": [
      {
        "indexed": false,
        "internalType": "uint256",
        "name": "maxDrop",
        "type": "uint256"
      }
    ],
    "name": "MaxDropUpdated",
    "type": "event"
  },
  {
    "anonymous": false,
    "inputs": [
      {
        "indexed": true,
        "internalType": "address",
        "name": "operator",
        "type": "address"
      }
    ],
    "name": "OperatorUpdated",
    "type": "event"
  },
  {
    "anonymous": false,
    "inputs": [
      {
        "indexed": true,
        "internalType": "address",
        "name": "previousOwner",
        "type": "address"
      },
      {
        "indexed": true,
        "internalType": "address",
        "name": "newOwner",
        "type": "address"
      }
    ],
    "name": "OwnershipTransferStarted",
    "type": "event"
  },
  {
    "anonymous": false,
    "inputs": [
      {
        "indexed": true,
        "internalType": "address",
        "name": "previousOwner",
        "type": "address"
      },
      {
        "indexed": true,
        "internalType": "address",
        "name": "newOwner",
        "type": "address"
      }
    ],
    "name": "OwnershipTransferred",
    "type": "event"
  },
  {
    "anonymous": false,
    "inputs": [
      {
        "indexed": false,
        "internalType": "address",
        "name": "account",
        "type": "address"
      }
    ],
    "name": "Paused",
    "type": "event"
  },
  {
    "anonymous": false,
    "inputs": [
      {
        "indexed": false,
        "internalType": "address",
        "name": "account",
        "type": "address"
      }
    ],
    "name": "Unpaused",
    "type": "event"
  },
  {
    "inputs": [],
    "name": "acceptOwnership",
    "outputs": [],
    "stateMutability": "nonpayable",
    "type": "function"
  },
  {
    "inputs": [
      {
        "internalType": "bytes32",
        "name": "claimId",
        "type": "bytes32"
      }
    ],
    "name": "claimed",
    "outputs": [
      {
        "internalType": "bool",
        "name": "",
        "type": "bool"
      }
    ],
    "stateMutability": "view",
    "type": "function"
  },
  {
    "inputs": [
      {
        "internalType": "bytes32",
        "name": "claimId",
        "type": "bytes32"
      },
      {
        "internalType": "address",
        "name": "to",
        "type": "address"
      },
      {
        "internalType": "uint256",
        "name": "amount",
        "type": "uint256"
      }
    ],
    "name": "drop",
    "outputs": [],
    "stateMutability": "nonpayable",
    "type": "function"
  },
  {
    "inputs": [],
    "name": "maxDrop",
    "outputs": [
      {
        "internalType": "uint256",
        "name": "",
        "type": "uint256"
      }
    ],
    "stateMutability": "view",
    "type": "function"
  },
  {
    "inputs": [],
    "name": "operator",
    "outputs": [
      {
        "internalType": "address",
        "name": "",
        "type": "address"
      }
    ],
    "stateMutability": "view",
    "type": "function"
  },
  {
    "inputs": [],
    "name": "owner",
    "outputs": [
      {
        "internalType": "address",
        "name": "",
        "type": "address"
      }
    ],
    "stateMutability": "view",
    "type": "function"
  },
  {
    "inputs": [],
    "name": "pause",
    "outputs": [],
    "stateMutability": "nonpayable",
    "type": "function"
  },
  {
    "inputs": [],
    "name": "paused",
    "outputs": [
      {
        "internalType": "bool",
        "name": "",
        "type": "bool"
      }
    ],
    "stateMutability": "view",
    "type": "function"
  },
  {
    "inputs": [],
    "name": "pendingOwner",
    "outputs": [
      {
        "internalType": "address",
        "name": "",
        "type": "address"
      }
    ],
    "stateMutability": "view",
    "type": "function"
  },
  {
    "inputs": [],
    "name": "renounceOwnership",
    "outputs": [],
    "stateMutability": "nonpayable",
    "type": "function"
  },
  {
    "inputs": [
      {
        "internalType": "uint256",
        "name": "maxDrop_",
        "type": "uint256"
      }
    ],
    "name": "setMaxDrop",
    "outputs": [],
    "stateMutability": "nonpayable",
    "type": "function"
  },
  {
    "inputs": [
      {
        "internalType": "address",
        "name": "operator_",
        "type": "address"
      }
    ],
    "name": "setOperator",
    "outputs": [],
    "stateMutability": "nonpayable",
    "type": "function"
  },
  {
    "inputs": [],
    "name": "token",
    "outputs": [
      {
        "internalType": "contract IERC20",
        "name": "",
        "type": "address"
      }
    ],
    "stateMutability": "view",
    "type": "function"
  },
  {
    "inputs": [
      {
        "internalType": "address",
        "name": "newOwner",
        "type": "address"
      }
    ],
    "name": "transferOwnership",
    "outputs": [],
    "stateMutability": "nonpayable",
    "type": "function"
  },
  {
    "inputs": [],
    "name": "unpause",
    "outputs": [],
    "stateMutability": "nonpayable",
    "type": "function"
  }
]

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.26;

import {Ownable} from "@openzeppelin/contracts/access/Ownable.sol";
import {Ownable2Step} from "@openzeppelin/contracts/access/Ownable2Step.sol";
import {Pausable} from "@openzeppelin/contracts/utils/Pausable.sol";
import {IERC20} from "@openzeppelin/contracts/token/ERC20/IERC20.sol";
import {SafeERC20} from "@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol";

/// @notice Holds a token balance and pays it out via `drop`: at most one
/// payout per claim id, at most `maxDrop` per payout, callable only by the
/// operator. The owner can replace the operator, change `maxDrop` and pause.
contract TreasuryDropper is Ownable2Step, Pausable {
    using SafeERC20 for IERC20;

    error NotOperator();
    error ZeroAddress();
    error InvalidAmount();
    error AlreadyClaimed(bytes32 claimId);

    event Dropped(bytes32 indexed claimId, address indexed to, uint256 amount);
    event OperatorUpdated(address indexed operator);
    event MaxDropUpdated(uint256 maxDrop);

    IERC20 public immutable token;
    address public operator;
    uint256 public maxDrop;
    mapping(bytes32 claimId => bool) public claimed;

    constructor(address token_, address owner_, address operator_, uint256 maxDrop_) Ownable(owner_) {
        if (token_ == address(0) || operator_ == address(0)) revert ZeroAddress();
        if (maxDrop_ == 0) revert InvalidAmount();
        token = IERC20(token_);
        operator = operator_;
        maxDrop = maxDrop_;
    }

    function drop(bytes32 claimId, address to, uint256 amount) external whenNotPaused {
        if (msg.sender != operator) revert NotOperator();
        if (to == address(0)) revert ZeroAddress();
        if (amount == 0 || amount > maxDrop) revert InvalidAmount();
        if (claimed[claimId]) revert AlreadyClaimed(claimId);
        claimed[claimId] = true;
        token.safeTransfer(to, amount);
        emit Dropped(claimId, to, amount);
    }

    function setOperator(address operator_) external onlyOwner {
        if (operator_ == address(0)) revert ZeroAddress();
        operator = operator_;
        emit OperatorUpdated(operator_);
    }

    function setMaxDrop(uint256 maxDrop_) external onlyOwner {
        if (maxDrop_ == 0) revert InvalidAmount();
        maxDrop = maxDrop_;
        emit MaxDropUpdated(maxDrop_);
    }

    function pause() external onlyOwner {
        _pause();
    }

    function unpause() external onlyOwner {
        _unpause();
    }
}