pragma solidity ^0.8.13;

contract ReceiptMint {
    event Receipt(address indexed minter, bytes32 indexed payload, address indexed receiptAddress);
    mapping(address => uint256) public receiptBlock;

    error Exists();
    error Create2Failed();

    function mint(bytes32 payload) external returns (address receiptAddress) {
        bytes32 salt = keccak256(abi.encodePacked(block.chainid, msg.sender, payload));
        bytes memory init = hex"60016000f3";
        bytes32 initHash = keccak256(init);

        receiptAddress = address(uint160(uint256(keccak256(abi.encodePacked(
            hex"ff",
            address(this),
            salt,
            initHash
        )))));

        if (receiptAddress == address(0) || receiptAddress.code.length != 0) revert Exists();

        address deployed;
        assembly {
            deployed := create2(0, add(init, 0x20), mload(init), salt)
        }
        if (deployed != receiptAddress) revert Create2Failed();

        receiptBlock[deployed] = block.timestamp;
        emit Receipt(msg.sender, payload, deployed);
    }
}