IHooks.sol

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

import {PoolKey} from "../types/PoolKey.sol";
import {BalanceDelta} from "../types/BalanceDelta.sol";
import {IPoolManager} from "./IPoolManager.sol";
import {BeforeSwapDelta} from "../types/BeforeSwapDelta.sol";

/// @notice The PoolManager contract decides whether to invoke specific hooks by inspecting the leading bits
/// of the hooks contract address. For example, a 1 bit in the first bit of the address will
/// cause the 'before swap' hook to be invoked. See the Hooks library for the full spec.
/// @dev Should only be callable by the v4 PoolManager.
interface IHooks {
    /// @notice The hook called before the state of a pool is initialized
    /// @param sender The initial msg.sender for the initialize call
    /// @param key The key for the pool being initialized
    /// @param sqrtPriceX96 The sqrt(price) of the pool as a Q64.96
    /// @param hookData Arbitrary data handed into the PoolManager by the initializer to be be passed on to the hook
    /// @return bytes4 The function selector for the hook
    function beforeInitialize(address sender, PoolKey calldata key, uint160 sqrtPriceX96, bytes calldata hookData)
        external
        returns (bytes4);

    /// @notice The hook called after the state of a pool is initialized
    /// @param sender The initial msg.sender for the initialize call
    /// @param key The key for the pool being initialized
    /// @param sqrtPriceX96 The sqrt(price) of the pool as a Q64.96
    /// @param tick The current tick after the state of a pool is initialized
    /// @param hookData Arbitrary data handed into the PoolManager by the initializer to be be passed on to the hook
    /// @return bytes4 The function selector for the hook
    function afterInitialize(
        address sender,
        PoolKey calldata key,
        uint160 sqrtPriceX96,
        int24 tick,
        bytes calldata hookData
    ) external returns (bytes4);

    /// @notice The hook called before liquidity is added
    /// @param sender The initial msg.sender for the add liquidity call
    /// @param key The key for the pool
    /// @param params The parameters for adding liquidity
    /// @param hookData Arbitrary data handed into the PoolManager by the liquidity provider to be passed on to the hook
    /// @return bytes4 The function selector for the hook
    function beforeAddLiquidity(
        address sender,
        PoolKey calldata key,
        IPoolManager.ModifyLiquidityParams calldata params,
        bytes calldata hookData
    ) external returns (bytes4);

    /// @notice The hook called after liquidity is added
    /// @param sender The initial msg.sender for the add liquidity call
    /// @param key The key for the pool
    /// @param params The parameters for adding liquidity
    /// @param hookData Arbitrary data handed into the PoolManager by the liquidity provider to be passed on to the hook
    /// @return bytes4 The function selector for the hook
    /// @return BalanceDelta The hook's delta in token0 and token1. Positive: the hook is owed/took currency, negative: the hook owes/sent currency
    function afterAddLiquidity(
        address sender,
        PoolKey calldata key,
        IPoolManager.ModifyLiquidityParams calldata params,
        BalanceDelta delta,
        bytes calldata hookData
    ) external returns (bytes4, BalanceDelta);

    /// @notice The hook called before liquidity is removed
    /// @param sender The initial msg.sender for the remove liquidity call
    /// @param key The key for the pool
    /// @param params The parameters for removing liquidity
    /// @param hookData Arbitrary data handed into the PoolManager by the liquidty provider to be be passed on to the hook
    /// @return bytes4 The function selector for the hook
    function beforeRemoveLiquidity(
        address sender,
        PoolKey calldata key,
        IPoolManager.ModifyLiquidityParams calldata params,
        bytes calldata hookData
    ) external returns (bytes4);

    /// @notice The hook called after liquidity is removed
    /// @param sender The initial msg.sender for the remove liquidity call
    /// @param key The key for the pool
    /// @param params The parameters for removing liquidity
    /// @param hookData Arbitrary data handed into the PoolManager by the liquidty provider to be be passed on to the hook
    /// @return bytes4 The function selector for the hook
    /// @return BalanceDelta The hook's delta in token0 and token1. Positive: the hook is owed/took currency, negative: the hook owes/sent currency
    function afterRemoveLiquidity(
        address sender,
        PoolKey calldata key,
        IPoolManager.ModifyLiquidityParams calldata params,
        BalanceDelta delta,
        bytes calldata hookData
    ) external returns (bytes4, BalanceDelta);

    /// @notice The hook called before a swap
    /// @param sender The initial msg.sender for the swap call
    /// @param key The key for the pool
    /// @param params The parameters for the swap
    /// @param hookData Arbitrary data handed into the PoolManager by the swapper to be be passed on to the hook
    /// @return bytes4 The function selector for the hook
    /// @return BeforeSwapDelta The hook's delta in specified and unspecified currencies. Positive: the hook is owed/took currency, negative: the hook owes/sent currency
    /// @return uint24 Optionally override the lp fee, only used if three conditions are met: 1) the Pool has a dynamic fee, 2) the value's leading bit is set to 1 (24th bit, 0x800000), 3) the value is less than or equal to the maximum fee (1 million)
    function beforeSwap(
        address sender,
        PoolKey calldata key,
        IPoolManager.SwapParams calldata params,
        bytes calldata hookData
    ) external returns (bytes4, BeforeSwapDelta, uint24);

    /// @notice The hook called after a swap
    /// @param sender The initial msg.sender for the swap call
    /// @param key The key for the pool
    /// @param params The parameters for the swap
    /// @param delta The amount owed to the caller (positive) or owed to the pool (negative)
    /// @param hookData Arbitrary data handed into the PoolManager by the swapper to be be passed on to the hook
    /// @return bytes4 The function selector for the hook
    /// @return int128 The hook's delta in unspecified currency. Positive: the hook is owed/took currency, negative: the hook owes/sent currency
    function afterSwap(
        address sender,
        PoolKey calldata key,
        IPoolManager.SwapParams calldata params,
        BalanceDelta delta,
        bytes calldata hookData
    ) external returns (bytes4, int128);

    /// @notice The hook called before donate
    /// @param sender The initial msg.sender for the donate call
    /// @param key The key for the pool
    /// @param amount0 The amount of token0 being donated
    /// @param amount1 The amount of token1 being donated
    /// @param hookData Arbitrary data handed into the PoolManager by the donor to be be passed on to the hook
    /// @return bytes4 The function selector for the hook
    function beforeDonate(
        address sender,
        PoolKey calldata key,
        uint256 amount0,
        uint256 amount1,
        bytes calldata hookData
    ) external returns (bytes4);

    /// @notice The hook called after donate
    /// @param sender The initial msg.sender for the donate call
    /// @param key The key for the pool
    /// @param amount0 The amount of token0 being donated
    /// @param amount1 The amount of token1 being donated
    /// @param hookData Arbitrary data handed into the PoolManager by the donor to be be passed on to the hook
    /// @return bytes4 The function selector for the hook
    function afterDonate(
        address sender,
        PoolKey calldata key,
        uint256 amount0,
        uint256 amount1,
        bytes calldata hookData
    ) external returns (bytes4);
}