TWAP Deviation

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

import {Assertion} from "../lib/credible-std/Assertion.sol";

interface IPool {
    function price() external view returns (uint256);
    function twap() external view returns (uint256);
}

// Checks that the pool price doesn't deviate more than 5% from the twap
contract TwapDeviationAssertion is Assertion {
    IPool public pool = IPool(address(0xbeef));

    function fnSelectors() external pure override returns (Trigger[] memory) {
        Trigger[] memory triggers = new Trigger[](1); // Define the number of triggers
        triggers[0] = Trigger(TriggerType.STORAGE, this.assertionTwapDeviation.selector); // Define the trigger
        return triggers;
    }

    // Make sure that the price doesn't deviate more than 5% from the twap
    // return true indicates a valid state
    // return false indicates an invalid state
    function assertionTwapDeviation() external returns (bool) {
        ph.forkPostState();
        uint256 currentPrice = pool.price();
        uint256 twapPrice = pool.twap();
        uint256 maxDeviation = 5; // 5% deviation, define this according to your protocol
        uint256 deviation = (((currentPrice > twapPrice) ? currentPrice - twapPrice : twapPrice - currentPrice) * 100) /
            twapPrice;
        return deviation <= maxDeviation;
    }
}