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

import {BaseHook} from "v4-periphery/src/base/hooks/BaseHook.sol";
import {IPoolManager} from "v4-core/src/interfaces/IPoolManager.sol";
import {PoolKey} from "v4-core/src/types/PoolKey.sol";
import {Hooks} from "v4-core/src/libraries/Hooks.sol";
import {BeforeSwapDelta, BeforeSwapDeltaLibrary} from "v4-core/src/types/BeforeSwapDelta.sol";

contract MaxSwapHook is BaseHook {

    uint256 public maxSwapAmount;

    constructor(IPoolManager _poolManager, uint256 _maxSwapAmount) BaseHook(_poolManager) {
        maxSwapAmount = _maxSwapAmount;
    }

    function getHookPermissions() public pure override returns (Hooks.Permissions memory) {
        return Hooks.Permissions({
            beforeInitialize: false,
            afterInitialize: false,
            beforeAddLiquidity: false,
            afterAddLiquidity: false,
            beforeRemoveLiquidity: false,
            afterRemoveLiquidity: false,
            beforeSwap: true,
            afterSwap: false,
            beforeDonate: false,
            afterDonate: false
        });
    }

    function beforeSwap(
        address,
        PoolKey calldata,
        IPoolManager.SwapParams calldata params,
        bytes calldata
    ) external override onlyPoolManager returns (bytes4, BeforeSwapDelta, uint24) {

        require(
            _abs(params.amountSpecified) <= int256(maxSwapAmount),
            "Swap exceeds maximum allowed amount"
        );

        return (BaseHook.beforeSwap.selector, BeforeSwapDeltaLibrary.ZERO_DELTA, 0);
    }

    function _abs(int256 x) internal pure returns (int256) {
        return x < 0 ? -x : x;
    }
}