KittyCoin

[
  {
    "inputs": [
      {
        "internalType": "address",
        "name": "_main",
        "type": "address"
      }
    ],
    "stateMutability": "nonpayable",
    "type": "constructor"
  },
  {
    "inputs": [],
    "name": "AllowanceOverflow",
    "type": "error"
  },
  {
    "inputs": [],
    "name": "AllowanceUnderflow",
    "type": "error"
  },
  {
    "inputs": [],
    "name": "CapExceeded",
    "type": "error"
  },
  {
    "inputs": [],
    "name": "InsufficientAllowance",
    "type": "error"
  },
  {
    "inputs": [],
    "name": "InsufficientBalance",
    "type": "error"
  },
  {
    "inputs": [],
    "name": "InvalidPermit",
    "type": "error"
  },
  {
    "inputs": [],
    "name": "NotMain",
    "type": "error"
  },
  {
    "inputs": [],
    "name": "Permit2AllowanceIsFixedAtInfinity",
    "type": "error"
  },
  {
    "inputs": [],
    "name": "PermitExpired",
    "type": "error"
  },
  {
    "inputs": [],
    "name": "TotalSupplyOverflow",
    "type": "error"
  },
  {
    "anonymous": false,
    "inputs": [
      {
        "indexed": true,
        "internalType": "address",
        "name": "owner",
        "type": "address"
      },
      {
        "indexed": true,
        "internalType": "address",
        "name": "spender",
        "type": "address"
      },
      {
        "indexed": false,
        "internalType": "uint256",
        "name": "amount",
        "type": "uint256"
      }
    ],
    "name": "Approval",
    "type": "event"
  },
  {
    "anonymous": false,
    "inputs": [
      {
        "indexed": true,
        "internalType": "address",
        "name": "from",
        "type": "address"
      },
      {
        "indexed": true,
        "internalType": "address",
        "name": "to",
        "type": "address"
      },
      {
        "indexed": false,
        "internalType": "uint256",
        "name": "amount",
        "type": "uint256"
      }
    ],
    "name": "Transfer",
    "type": "event"
  },
  {
    "inputs": [],
    "name": "DOMAIN_SEPARATOR",
    "outputs": [
      {
        "internalType": "bytes32",
        "name": "result",
        "type": "bytes32"
      }
    ],
    "stateMutability": "view",
    "type": "function"
  },
  {
    "inputs": [],
    "name": "MAX_SUPPLY",
    "outputs": [
      {
        "internalType": "uint256",
        "name": "",
        "type": "uint256"
      }
    ],
    "stateMutability": "view",
    "type": "function"
  },
  {
    "inputs": [
      {
        "internalType": "address",
        "name": "owner",
        "type": "address"
      },
      {
        "internalType": "address",
        "name": "spender",
        "type": "address"
      }
    ],
    "name": "allowance",
    "outputs": [
      {
        "internalType": "uint256",
        "name": "result",
        "type": "uint256"
      }
    ],
    "stateMutability": "view",
    "type": "function"
  },
  {
    "inputs": [],
    "name": "amtBurned",
    "outputs": [
      {
        "internalType": "uint256",
        "name": "",
        "type": "uint256"
      }
    ],
    "stateMutability": "view",
    "type": "function"
  },
  {
    "inputs": [
      {
        "internalType": "address",
        "name": "spender",
        "type": "address"
      },
      {
        "internalType": "uint256",
        "name": "amount",
        "type": "uint256"
      }
    ],
    "name": "approve",
    "outputs": [
      {
        "internalType": "bool",
        "name": "",
        "type": "bool"
      }
    ],
    "stateMutability": "nonpayable",
    "type": "function"
  },
  {
    "inputs": [
      {
        "internalType": "address",
        "name": "owner",
        "type": "address"
      }
    ],
    "name": "balanceOf",
    "outputs": [
      {
        "internalType": "uint256",
        "name": "result",
        "type": "uint256"
      }
    ],
    "stateMutability": "view",
    "type": "function"
  },
  {
    "inputs": [
      {
        "internalType": "uint256",
        "name": "value",
        "type": "uint256"
      }
    ],
    "name": "burn",
    "outputs": [],
    "stateMutability": "nonpayable",
    "type": "function"
  },
  {
    "inputs": [],
    "name": "decimals",
    "outputs": [
      {
        "internalType": "uint8",
        "name": "",
        "type": "uint8"
      }
    ],
    "stateMutability": "pure",
    "type": "function"
  },
  {
    "inputs": [],
    "name": "main",
    "outputs": [
      {
        "internalType": "address",
        "name": "",
        "type": "address"
      }
    ],
    "stateMutability": "view",
    "type": "function"
  },
  {
    "inputs": [
      {
        "internalType": "address",
        "name": "to",
        "type": "address"
      },
      {
        "internalType": "uint256",
        "name": "amt",
        "type": "uint256"
      }
    ],
    "name": "mint",
    "outputs": [],
    "stateMutability": "nonpayable",
    "type": "function"
  },
  {
    "inputs": [],
    "name": "name",
    "outputs": [
      {
        "internalType": "string",
        "name": "",
        "type": "string"
      }
    ],
    "stateMutability": "pure",
    "type": "function"
  },
  {
    "inputs": [
      {
        "internalType": "address",
        "name": "owner",
        "type": "address"
      }
    ],
    "name": "nonces",
    "outputs": [
      {
        "internalType": "uint256",
        "name": "result",
        "type": "uint256"
      }
    ],
    "stateMutability": "view",
    "type": "function"
  },
  {
    "inputs": [
      {
        "internalType": "address",
        "name": "owner",
        "type": "address"
      },
      {
        "internalType": "address",
        "name": "spender",
        "type": "address"
      },
      {
        "internalType": "uint256",
        "name": "value",
        "type": "uint256"
      },
      {
        "internalType": "uint256",
        "name": "deadline",
        "type": "uint256"
      },
      {
        "internalType": "uint8",
        "name": "v",
        "type": "uint8"
      },
      {
        "internalType": "bytes32",
        "name": "r",
        "type": "bytes32"
      },
      {
        "internalType": "bytes32",
        "name": "s",
        "type": "bytes32"
      }
    ],
    "name": "permit",
    "outputs": [],
    "stateMutability": "nonpayable",
    "type": "function"
  },
  {
    "inputs": [],
    "name": "symbol",
    "outputs": [
      {
        "internalType": "string",
        "name": "",
        "type": "string"
      }
    ],
    "stateMutability": "pure",
    "type": "function"
  },
  {
    "inputs": [],
    "name": "totalSupply",
    "outputs": [
      {
        "internalType": "uint256",
        "name": "result",
        "type": "uint256"
      }
    ],
    "stateMutability": "view",
    "type": "function"
  },
  {
    "inputs": [
      {
        "internalType": "address",
        "name": "to",
        "type": "address"
      },
      {
        "internalType": "uint256",
        "name": "amount",
        "type": "uint256"
      }
    ],
    "name": "transfer",
    "outputs": [
      {
        "internalType": "bool",
        "name": "",
        "type": "bool"
      }
    ],
    "stateMutability": "nonpayable",
    "type": "function"
  },
  {
    "inputs": [
      {
        "internalType": "address",
        "name": "from",
        "type": "address"
      },
      {
        "internalType": "address",
        "name": "to",
        "type": "address"
      },
      {
        "internalType": "uint256",
        "name": "amount",
        "type": "uint256"
      }
    ],
    "name": "transferFrom",
    "outputs": [
      {
        "internalType": "bool",
        "name": "",
        "type": "bool"
      }
    ],
    "stateMutability": "nonpayable",
    "type": "function"
  }
]

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.28;

import {ERC20} from "solady/tokens/ERC20.sol";
import {Errors} from "./libraries/Errors.sol";

/**
 * @title KittyCoin
 * @notice The mining reward ERC-20 for the KittyMining game.
 *
 * @dev EDIT (whole file): the live OGcoin ERC-20 source is NOT present in this repo —
 *      only its interface (MainV2/src/interfaces/IOGcoin.sol) is. This contract is
 *      therefore INFERRED from that interface plus how MainV2 uses it:
 *        - mint(to, amt): called only by the game (MainV2._mint enforces the cap as
 *          amtBurned + totalSupply + amount <= MAX_SUPPLY before calling mint).
 *        - burn(value):   the game burns from its own balance after purchases.
 *        - amtBurned():   cumulative burned amount, read by the game's cap check.
 *      Per spec, mint AND burn are restricted to the game contract, and the token
 *      additionally enforces the 100M hard cap itself (defense in depth — the game's
 *      cap check in KittyMining._mint remains the primary check, copied verbatim
 *      from MainV2).
 */
contract KittyCoin is ERC20 {
    /// @dev maximum supply: burned + circulating can never exceed this
    uint256 public constant MAX_SUPPLY = 100_000_000e18;

    /// @dev The KittyMining game contract; sole minter/burner. Named `main` to match
    ///      the Miners NFT reference naming.
    address public immutable main;

    /// @dev Cumulative amount burned (burned tokens free no cap room).
    uint256 public amtBurned;

    error CapExceeded();

    constructor(address _main) {
        main = _main;
    }

    function name() public pure override returns (string memory) {
        return "KittyCoin";
    }

    function symbol() public pure override returns (string memory) {
        return "KITTY";
    }

    /// @dev 18 decimals (solady ERC20 default), stated explicitly for clarity.
    function decimals() public pure override returns (uint8) {
        return 18;
    }

    /**
     * @notice Mint rewards. Only callable by the game contract.
     * @dev Enforces burned + supply + amount <= MAX_SUPPLY, mirroring MainV2._mint.
     */
    function mint(address to, uint256 amt) external {
        require(msg.sender == main, Errors.NotMain());
        require(amtBurned + totalSupply() + amt <= MAX_SUPPLY, CapExceeded());
        _mint(to, amt);
    }

    /**
     * @notice Burn tokens from the caller's balance. Only callable by the game contract.
     */
    function burn(uint256 value) external {
        require(msg.sender == main, Errors.NotMain());
        amtBurned += value;
        _burn(msg.sender, value);
    }
}