ZxoarLauncher

[
  {
    "inputs": [
      {
        "internalType": "contract IPoolManager",
        "name": "poolManager_",
        "type": "address"
      },
      {
        "internalType": "contract IHooks",
        "name": "hook_",
        "type": "address"
      },
      {
        "internalType": "address",
        "name": "protocolFeeRecipient_",
        "type": "address"
      },
      {
        "internalType": "contract IWETH",
        "name": "weth_",
        "type": "address"
      },
      {
        "internalType": "address",
        "name": "router_",
        "type": "address"
      }
    ],
    "stateMutability": "nonpayable",
    "type": "constructor"
  },
  {
    "inputs": [],
    "name": "AlreadyGraduated",
    "type": "error"
  },
  {
    "inputs": [],
    "name": "CurveNotFilled",
    "type": "error"
  },
  {
    "inputs": [],
    "name": "MetadataUriTooLong",
    "type": "error"
  },
  {
    "inputs": [],
    "name": "NotPoolManager",
    "type": "error"
  },
  {
    "inputs": [],
    "name": "NotRouter",
    "type": "error"
  },
  {
    "inputs": [],
    "name": "UnexpectedEthOwed",
    "type": "error"
  },
  {
    "inputs": [],
    "name": "UnknownToken",
    "type": "error"
  },
  {
    "inputs": [],
    "name": "ZeroAddress",
    "type": "error"
  },
  {
    "anonymous": false,
    "inputs": [
      {
        "indexed": true,
        "internalType": "address",
        "name": "token",
        "type": "address"
      },
      {
        "indexed": true,
        "internalType": "address",
        "name": "creator",
        "type": "address"
      },
      {
        "indexed": false,
        "internalType": "uint256",
        "name": "ethAmount",
        "type": "uint256"
      },
      {
        "indexed": false,
        "internalType": "uint256",
        "name": "tokenAmount",
        "type": "uint256"
      },
      {
        "indexed": false,
        "internalType": "bool",
        "name": "creatorWethFallback",
        "type": "bool"
      },
      {
        "indexed": false,
        "internalType": "bool",
        "name": "protocolWethFallback",
        "type": "bool"
      }
    ],
    "name": "FeesCollected",
    "type": "event"
  },
  {
    "anonymous": false,
    "inputs": [
      {
        "indexed": true,
        "internalType": "address",
        "name": "token",
        "type": "address"
      },
      {
        "indexed": false,
        "internalType": "uint128",
        "name": "gradLiquidity",
        "type": "uint128"
      }
    ],
    "name": "Graduated",
    "type": "event"
  },
  {
    "anonymous": false,
    "inputs": [
      {
        "indexed": true,
        "internalType": "address",
        "name": "token",
        "type": "address"
      },
      {
        "indexed": true,
        "internalType": "address",
        "name": "creator",
        "type": "address"
      },
      {
        "indexed": true,
        "internalType": "PoolId",
        "name": "poolId",
        "type": "bytes32"
      },
      {
        "indexed": false,
        "internalType": "string",
        "name": "name",
        "type": "string"
      },
      {
        "indexed": false,
        "internalType": "string",
        "name": "symbol",
        "type": "string"
      },
      {
        "indexed": false,
        "internalType": "string",
        "name": "metadataURI",
        "type": "string"
      },
      {
        "indexed": false,
        "internalType": "uint128",
        "name": "liquidity",
        "type": "uint128"
      }
    ],
    "name": "TokenLaunched",
    "type": "event"
  },
  {
    "inputs": [],
    "name": "CURVE_SUPPLY",
    "outputs": [
      {
        "internalType": "uint256",
        "name": "",
        "type": "uint256"
      }
    ],
    "stateMutability": "view",
    "type": "function"
  },
  {
    "inputs": [],
    "name": "GRAD_RESERVE",
    "outputs": [
      {
        "internalType": "uint256",
        "name": "",
        "type": "uint256"
      }
    ],
    "stateMutability": "view",
    "type": "function"
  },
  {
    "inputs": [],
    "name": "GRAD_TICK_LOWER",
    "outputs": [
      {
        "internalType": "int24",
        "name": "",
        "type": "int24"
      }
    ],
    "stateMutability": "view",
    "type": "function"
  },
  {
    "inputs": [],
    "name": "MAX_METADATA_URI_BYTES",
    "outputs": [
      {
        "internalType": "uint256",
        "name": "",
        "type": "uint256"
      }
    ],
    "stateMutability": "view",
    "type": "function"
  },
  {
    "inputs": [],
    "name": "TICK_LOWER",
    "outputs": [
      {
        "internalType": "int24",
        "name": "",
        "type": "int24"
      }
    ],
    "stateMutability": "view",
    "type": "function"
  },
  {
    "inputs": [],
    "name": "TICK_SPACING",
    "outputs": [
      {
        "internalType": "int24",
        "name": "",
        "type": "int24"
      }
    ],
    "stateMutability": "view",
    "type": "function"
  },
  {
    "inputs": [],
    "name": "TICK_UPPER",
    "outputs": [
      {
        "internalType": "int24",
        "name": "",
        "type": "int24"
      }
    ],
    "stateMutability": "view",
    "type": "function"
  },
  {
    "inputs": [],
    "name": "TOTAL_SUPPLY",
    "outputs": [
      {
        "internalType": "uint256",
        "name": "",
        "type": "uint256"
      }
    ],
    "stateMutability": "view",
    "type": "function"
  },
  {
    "inputs": [
      {
        "internalType": "uint256",
        "name": "",
        "type": "uint256"
      }
    ],
    "name": "allTokens",
    "outputs": [
      {
        "internalType": "address",
        "name": "",
        "type": "address"
      }
    ],
    "stateMutability": "view",
    "type": "function"
  },
  {
    "inputs": [
      {
        "internalType": "address",
        "name": "token",
        "type": "address"
      }
    ],
    "name": "buyTickLimit",
    "outputs": [
      {
        "internalType": "int24",
        "name": "",
        "type": "int24"
      }
    ],
    "stateMutability": "view",
    "type": "function"
  },
  {
    "inputs": [
      {
        "internalType": "address",
        "name": "token",
        "type": "address"
      }
    ],
    "name": "collectFees",
    "outputs": [
      {
        "internalType": "uint256",
        "name": "ethAmount",
        "type": "uint256"
      },
      {
        "internalType": "uint256",
        "name": "tokenAmount",
        "type": "uint256"
      }
    ],
    "stateMutability": "nonpayable",
    "type": "function"
  },
  {
    "inputs": [
      {
        "internalType": "address",
        "name": "token",
        "type": "address"
      }
    ],
    "name": "graduate",
    "outputs": [
      {
        "internalType": "uint128",
        "name": "gradLiquidity",
        "type": "uint128"
      }
    ],
    "stateMutability": "nonpayable",
    "type": "function"
  },
  {
    "inputs": [
      {
        "internalType": "address",
        "name": "",
        "type": "address"
      }
    ],
    "name": "graduated",
    "outputs": [
      {
        "internalType": "bool",
        "name": "",
        "type": "bool"
      }
    ],
    "stateMutability": "view",
    "type": "function"
  },
  {
    "inputs": [],
    "name": "hook",
    "outputs": [
      {
        "internalType": "contract IHooks",
        "name": "",
        "type": "address"
      }
    ],
    "stateMutability": "view",
    "type": "function"
  },
  {
    "inputs": [
      {
        "internalType": "string",
        "name": "name",
        "type": "string"
      },
      {
        "internalType": "string",
        "name": "symbol",
        "type": "string"
      },
      {
        "internalType": "string",
        "name": "metadataURI",
        "type": "string"
      }
    ],
    "name": "launch",
    "outputs": [
      {
        "internalType": "address",
        "name": "token",
        "type": "address"
      }
    ],
    "stateMutability": "nonpayable",
    "type": "function"
  },
  {
    "inputs": [
      {
        "internalType": "address",
        "name": "creator",
        "type": "address"
      },
      {
        "internalType": "string",
        "name": "name",
        "type": "string"
      },
      {
        "internalType": "string",
        "name": "symbol",
        "type": "string"
      },
      {
        "internalType": "string",
        "name": "metadataURI",
        "type": "string"
      }
    ],
    "name": "launchFor",
    "outputs": [
      {
        "internalType": "address",
        "name": "token",
        "type": "address"
      }
    ],
    "stateMutability": "nonpayable",
    "type": "function"
  },
  {
    "inputs": [
      {
        "internalType": "address",
        "name": "",
        "type": "address"
      }
    ],
    "name": "launches",
    "outputs": [
      {
        "internalType": "address",
        "name": "token",
        "type": "address"
      },
      {
        "internalType": "address",
        "name": "creator",
        "type": "address"
      },
      {
        "internalType": "string",
        "name": "metadataURI",
        "type": "string"
      },
      {
        "internalType": "uint64",
        "name": "createdAt",
        "type": "uint64"
      },
      {
        "internalType": "uint128",
        "name": "liquidity",
        "type": "uint128"
      }
    ],
    "stateMutability": "view",
    "type": "function"
  },
  {
    "inputs": [
      {
        "internalType": "address",
        "name": "token",
        "type": "address"
      }
    ],
    "name": "poolKeyFor",
    "outputs": [
      {
        "components": [
          {
            "internalType": "Currency",
            "name": "currency0",
            "type": "address"
          },
          {
            "internalType": "Currency",
            "name": "currency1",
            "type": "address"
          },
          {
            "internalType": "uint24",
            "name": "fee",
            "type": "uint24"
          },
          {
            "internalType": "int24",
            "name": "tickSpacing",
            "type": "int24"
          },
          {
            "internalType": "contract IHooks",
            "name": "hooks",
            "type": "address"
          }
        ],
        "internalType": "struct PoolKey",
        "name": "",
        "type": "tuple"
      }
    ],
    "stateMutability": "view",
    "type": "function"
  },
  {
    "inputs": [],
    "name": "poolManager",
    "outputs": [
      {
        "internalType": "contract IPoolManager",
        "name": "",
        "type": "address"
      }
    ],
    "stateMutability": "view",
    "type": "function"
  },
  {
    "inputs": [],
    "name": "protocolFeeRecipient",
    "outputs": [
      {
        "internalType": "address",
        "name": "",
        "type": "address"
      }
    ],
    "stateMutability": "view",
    "type": "function"
  },
  {
    "inputs": [],
    "name": "router",
    "outputs": [
      {
        "internalType": "address",
        "name": "",
        "type": "address"
      }
    ],
    "stateMutability": "view",
    "type": "function"
  },
  {
    "inputs": [],
    "name": "tokenCount",
    "outputs": [
      {
        "internalType": "uint256",
        "name": "",
        "type": "uint256"
      }
    ],
    "stateMutability": "view",
    "type": "function"
  },
  {
    "inputs": [
      {
        "internalType": "bytes",
        "name": "data",
        "type": "bytes"
      }
    ],
    "name": "unlockCallback",
    "outputs": [
      {
        "internalType": "bytes",
        "name": "",
        "type": "bytes"
      }
    ],
    "stateMutability": "nonpayable",
    "type": "function"
  },
  {
    "inputs": [],
    "name": "weth",
    "outputs": [
      {
        "internalType": "contract IWETH",
        "name": "",
        "type": "address"
      }
    ],
    "stateMutability": "view",
    "type": "function"
  },
  {
    "stateMutability": "payable",
    "type": "receive"
  }
]

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

import {ERC20} from "@openzeppelin/contracts/token/ERC20/ERC20.sol";
import {IERC20} from "@openzeppelin/contracts/token/ERC20/IERC20.sol";
import {SafeERC20} from "@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol";
import {ReentrancyGuard} from "@openzeppelin/contracts/security/ReentrancyGuard.sol";
import {IPoolManager} from "v4-core/src/interfaces/IPoolManager.sol";
import {IWETH} from "./interfaces/IWETH.sol";
import {IUnlockCallback} from "v4-core/src/interfaces/callback/IUnlockCallback.sol";
import {IHooks} from "v4-core/src/interfaces/IHooks.sol";
import {PoolKey} from "v4-core/src/types/PoolKey.sol";
import {PoolId, PoolIdLibrary} from "v4-core/src/types/PoolId.sol";
import {Currency} from "v4-core/src/types/Currency.sol";
import {BalanceDelta} from "v4-core/src/types/BalanceDelta.sol";
import {TickMath} from "v4-core/src/libraries/TickMath.sol";
import {FullMath} from "v4-core/src/libraries/FullMath.sol";
import {FixedPoint96} from "v4-core/src/libraries/FixedPoint96.sol";
import {LPFeeLibrary} from "v4-core/src/libraries/LPFeeLibrary.sol";
import {StateLibrary} from "v4-core/src/libraries/StateLibrary.sol";

/// @dev Fixed-supply token; the entire supply is minted to the launcher and
///      immediately deposited into the locked pool position. No owner, no
///      mint, no hooks — nothing a creator can rug with.
contract ZxoarToken is ERC20 {
    constructor(string memory n, string memory s, uint256 supply, address to) ERC20(n, s) {
        _mint(to, supply);
    }
}

/// @title ZxoarLauncher
/// @notice Agent-first fair-launch factory for Uniswap V4.
///
///         launch() in one transaction:
///           1. deploys a fixed-supply token,
///           2. initializes a native-ETH/token V4 pool wired to SnipeGuardHook
///              (dynamic fee: 50% -> 1% over 3 minutes),
///           3. deposits 95% of supply as a single-sided position spanning
///              [TICK_LOWER, TICK_UPPER] — the pool's own math is the bonding
///              curve — and escrows the remaining 5% as the graduation
///              reserve, deployed by permissionless graduate() as locked
///              open-market liquidity the moment the curve fills. There is
///              no migration, ever: 100% of supply is locked pool liquidity.
///
///         The position is owned by this contract and there is deliberately
///         no code path that removes liquidity: it is locked forever. Swap
///         fees accrued to the position are claimable via collectFees(),
///         split 50/50 between the token's creator and the protocol.
contract ZxoarLauncher is IUnlockCallback, ReentrancyGuard {
    using SafeERC20 for IERC20;
    using PoolIdLibrary for PoolKey;
    using StateLibrary for IPoolManager;

    // ---------------------------------------------------------------- config
    uint256 public constant TOTAL_SUPPLY = 1_000_000_000e18;
    int24 public constant TICK_SPACING = 200;
    /// @notice Max bytes for a token's metadataURI. Enforced on-chain so the
    ///         32KB cap the off-chain builder advertises is actually guaranteed,
    ///         and to bound the SSTORE cost / event size of a launch.
    uint256 public constant MAX_METADATA_URI_BYTES = 32_768;
    /// Price band, expressed in currency1-per-currency0 ticks (token per ETH).
    /// TICK_UPPER is the *launch* price (~1.4e-9 ETH per token, ~1.4 Ξ market
    /// cap); TICK_LOWER is the top of the ladder (~2.05e-8 ETH per token,
    /// ~20.5 Ξ market cap). ETH buys push the tick downward through the band.
    int24 public constant TICK_LOWER = 177_000;
    int24 public constant TICK_UPPER = 203_800;
    /// Graduation: 95% of supply forms the curve; 5% is escrowed here and
    /// deployed by permissionless graduate() as locked liquidity spanning
    /// [GRAD_TICK_LOWER, TICK_LOWER) — the same band width again (~14.6x more
    /// price runway, curve top ~20.6 ETH FDV -> graduated top ~300 ETH FDV).
    uint256 public constant CURVE_SUPPLY = 950_000_000e18;
    uint256 public constant GRAD_RESERVE = 50_000_000e18;
    int24 public constant GRAD_TICK_LOWER = 150_200;

    IPoolManager public immutable poolManager;
    IHooks public immutable hook;
    address public immutable protocolFeeRecipient;
    IWETH public immutable weth;
    address public immutable router;

    // -------------------------------------------------------------- registry
    struct Launch {
        address token;
        address creator;
        string metadataURI;
        uint64 createdAt;
        uint128 liquidity;
    }

    mapping(address => Launch) public launches; // token => Launch
    address[] public allTokens;
    mapping(address => bool) public graduated; // token => curve filled & seed deployed

    event TokenLaunched(
        address indexed token,
        address indexed creator,
        PoolId indexed poolId,
        string name,
        string symbol,
        string metadataURI,
        uint128 liquidity
    );
    event FeesCollected(
        address indexed token,
        address indexed creator,
        uint256 ethAmount,
        uint256 tokenAmount,
        bool creatorWethFallback,
        bool protocolWethFallback
    );

    event Graduated(address indexed token, uint128 gradLiquidity);

    error UnknownToken();
    error NotPoolManager();
    error NotRouter();
    error UnexpectedEthOwed();
    error ZeroAddress();
    error MetadataUriTooLong();
    error AlreadyGraduated();
    error CurveNotFilled();

    uint8 private constant ACTION_ADD = 1;
    uint8 private constant ACTION_COLLECT = 2;
    uint8 private constant ACTION_GRADUATE = 3;

    constructor(IPoolManager poolManager_, IHooks hook_, address protocolFeeRecipient_, IWETH weth_, address router_) {
        if (
            address(poolManager_) == address(0) || address(hook_) == address(0)
                || protocolFeeRecipient_ == address(0) || address(weth_) == address(0) || router_ == address(0)
        ) revert ZeroAddress();
        poolManager = poolManager_;
        hook = hook_;
        protocolFeeRecipient = protocolFeeRecipient_;
        weth = weth_;
        router = router_;
    }

    // -------------------------------------------------------------- launching

    /// @notice Launch a new token. Caller becomes the creator.
    function launch(string calldata name, string calldata symbol, string calldata metadataURI)
        external
        returns (address token)
    {
        return _launch(msg.sender, name, symbol, metadataURI);
    }

    /// @notice Launch a new token on behalf of a creator. Router-only.
    /// @dev Used by launchAndBuy to preserve creator attribution when the router
    ///      is msg.sender. Without this, all fee revenue would route to the router.
    function launchFor(address creator, string calldata name, string calldata symbol, string calldata metadataURI)
        external
        returns (address token)
    {
        if (msg.sender != router) revert NotRouter();
        return _launch(creator, name, symbol, metadataURI);
    }

    function _launch(address creator, string calldata name, string calldata symbol, string calldata metadataURI)
        internal
        returns (address token)
    {
        if (bytes(metadataURI).length > MAX_METADATA_URI_BYTES) revert MetadataUriTooLong();
        token = address(new ZxoarToken(name, symbol, TOTAL_SUPPLY, address(this)));
        PoolKey memory key = poolKeyFor(token);

        // Initialize exactly at the top tick of the band: the position is then
        // 100% token (currency1); the first ETH buy moves price into the band.
        uint160 sqrtStart = TickMath.getSqrtPriceAtTick(TICK_UPPER);
        poolManager.initialize(key, sqrtStart);

        // Liquidity such that the position holds the curve supply (95%); the
        // graduation reserve stays escrowed here until graduate().
        // amount1 = L * (sqrtU - sqrtL) / Q96  =>  L = supply * Q96 / (sqrtU - sqrtL)
        uint160 sqrtL = TickMath.getSqrtPriceAtTick(TICK_LOWER);
        uint160 sqrtU = sqrtStart;
        uint128 liquidity =
            uint128(FullMath.mulDiv(CURVE_SUPPLY, FixedPoint96.Q96, uint256(sqrtU - sqrtL)));

        poolManager.unlock(abi.encode(ACTION_ADD, token, liquidity));

        launches[token] = Launch({
            token: token,
            creator: creator,
            metadataURI: metadataURI,
            createdAt: uint64(block.timestamp),
            liquidity: liquidity
        });
        allTokens.push(token);

        emit TokenLaunched(token, creator, key.toId(), name, symbol, metadataURI, liquidity);
    }

    // ----------------------------------------------------------- fee stream

    /// @notice Claim swap fees accrued to the locked position for `token`.
    ///         Anyone can poke this; proceeds always split 50/50 between the
    ///         token's creator and the protocol. Principal cannot be touched.
    function collectFees(address token) external nonReentrant returns (uint256 ethAmount, uint256 tokenAmount) {
        Launch memory l = launches[token];
        if (l.token == address(0)) revert UnknownToken();

        bytes memory result = poolManager.unlock(abi.encode(ACTION_COLLECT, token, uint128(0)));
        (ethAmount, tokenAmount) = abi.decode(result, (uint256, uint256));

        uint256 ethCreator = ethAmount / 2;
        uint256 tokCreator = tokenAmount / 2;
        bool creatorFallback;
        bool protocolFallback;
        if (ethCreator > 0) creatorFallback = _sendEth(l.creator, ethCreator);
        if (ethAmount - ethCreator > 0) protocolFallback = _sendEth(protocolFeeRecipient, ethAmount - ethCreator);
        if (tokCreator > 0) IERC20(token).safeTransfer(l.creator, tokCreator);
        if (tokenAmount - tokCreator > 0) {
            IERC20(token).safeTransfer(protocolFeeRecipient, tokenAmount - tokCreator);
        }

        emit FeesCollected(token, l.creator, ethAmount, tokenAmount, creatorFallback, protocolFallback);
    }

    // ------------------------------------------------------------ graduation

    /// @notice Deploy the graduation reserve as locked open-market liquidity in
    ///         [GRAD_TICK_LOWER, TICK_LOWER). Permissionless — callable by
    ///         anyone once the curve is bought through its floor. One-way and
    ///         once per token; the seed is locked exactly like the curve.
    function graduate(address token) external nonReentrant returns (uint128 gradLiquidity) {
        Launch memory l = launches[token];
        if (l.token == address(0)) revert UnknownToken();
        if (graduated[token]) revert AlreadyGraduated();
        (, int24 tick,,) = poolManager.getSlot0(poolKeyFor(token).toId());
        if (tick > TICK_LOWER) revert CurveNotFilled();
        graduated[token] = true;

        uint160 sqrtGL = TickMath.getSqrtPriceAtTick(GRAD_TICK_LOWER);
        uint160 sqrtGU = TickMath.getSqrtPriceAtTick(TICK_LOWER);
        gradLiquidity = uint128(FullMath.mulDiv(GRAD_RESERVE, FixedPoint96.Q96, uint256(sqrtGU - sqrtGL)));
        poolManager.unlock(abi.encode(ACTION_GRADUATE, token, gradLiquidity));
        emit Graduated(token, gradLiquidity);
    }

    /// @notice Lowest tick routers may let buys reach: the curve floor before
    ///         graduation, the graduated-band floor after. Single source of
    ///         truth so no caller can walk price into empty tick space.
    function buyTickLimit(address token) public view returns (int24) {
        return graduated[token] ? GRAD_TICK_LOWER : TICK_LOWER;
    }

    // --------------------------------------------------------- v4 callback

    function unlockCallback(bytes calldata data) external returns (bytes memory) {
        if (msg.sender != address(poolManager)) revert NotPoolManager();
        (uint8 action, address token, uint128 liquidity) = abi.decode(data, (uint8, address, uint128));
        PoolKey memory key = poolKeyFor(token);

        if (action == ACTION_ADD || action == ACTION_GRADUATE) {
            bool grad = action == ACTION_GRADUATE;
            (BalanceDelta delta,) = poolManager.modifyLiquidity(
                key,
                IPoolManager.ModifyLiquidityParams({
                    tickLower: grad ? GRAD_TICK_LOWER : TICK_LOWER,
                    tickUpper: grad ? TICK_LOWER : TICK_UPPER,
                    liquidityDelta: int256(uint256(liquidity)),
                    salt: bytes32(0)
                }),
                ""
            );
            // Both mints owe only token (currency1): launch initializes at the
            // band top, and graduation mints at/above its range top. Any ETH
            // owed means price sits mid-band — revert; graduate() is retryable.
            if (delta.amount0() != 0) revert UnexpectedEthOwed();
            uint256 owed = uint256(uint128(-delta.amount1()));
            poolManager.sync(key.currency1);
            IERC20(token).safeTransfer(address(poolManager), owed);
            poolManager.settle();
            return "";
        }

        // ACTION_COLLECT: modifyLiquidity with zero delta realizes accrued fees.
        (BalanceDelta feeDelta,) = poolManager.modifyLiquidity(
            key,
            IPoolManager.ModifyLiquidityParams({
                tickLower: TICK_LOWER,
                tickUpper: TICK_UPPER,
                liquidityDelta: 0,
                salt: bytes32(0)
            }),
            ""
        );
        uint256 ethAmt = feeDelta.amount0() > 0 ? uint256(uint128(feeDelta.amount0())) : 0;
        uint256 tokAmt = feeDelta.amount1() > 0 ? uint256(uint128(feeDelta.amount1())) : 0;
        if (graduated[token]) {
            (BalanceDelta g,) = poolManager.modifyLiquidity(
                key,
                IPoolManager.ModifyLiquidityParams({
                    tickLower: GRAD_TICK_LOWER,
                    tickUpper: TICK_LOWER,
                    liquidityDelta: 0,
                    salt: bytes32(0)
                }),
                ""
            );
            if (g.amount0() > 0) ethAmt += uint256(uint128(g.amount0()));
            if (g.amount1() > 0) tokAmt += uint256(uint128(g.amount1()));
        }
        if (ethAmt > 0) poolManager.take(key.currency0, address(this), ethAmt);
        if (tokAmt > 0) poolManager.take(key.currency1, address(this), tokAmt);
        return abi.encode(ethAmt, tokAmt);
    }

    // ---------------------------------------------------------------- views

    function poolKeyFor(address token) public view returns (PoolKey memory) {
        return PoolKey({
            currency0: Currency.wrap(address(0)), // native ETH
            currency1: Currency.wrap(token),
            fee: LPFeeLibrary.DYNAMIC_FEE_FLAG,
            tickSpacing: TICK_SPACING,
            hooks: hook
        });
    }

    function tokenCount() external view returns (uint256) {
        return allTokens.length;
    }

    /// @dev Send ETH to `to`. If raw send fails (e.g. recipient is a contract
    ///      without payable receive), wrap to WETH and transfer instead.
    ///      WETH transfer cannot be recipient-reverted, so this never fails
    ///      for reasons outside our control.
    /// @return usedWethFallback True if raw send failed and WETH was used.
    function _sendEth(address to, uint256 amount) internal returns (bool usedWethFallback) {
        (bool ok,) = to.call{value: amount}("");
        if (!ok) {
            // Wrap to WETH and transfer — cannot be reverted by recipient
            weth.deposit{value: amount}();
            require(weth.transfer(to, amount), "weth transfer failed");
            return true;
        }
        return false;
    }

    receive() external payable {}
}