// SPDX-License-Identifier: GPL-3.0-or-later
pragma solidity ^0.8.19;

import { Kraiken } from "./Kraiken.sol";
import { Stake } from "./Stake.sol";
import { Math } from "@openzeppelin/utils/math/Math.sol";

import { Initializable } from "@openzeppelin/proxy/utils/Initializable.sol";
import { UUPSUpgradeable } from "@openzeppelin/proxy/utils/UUPSUpgradeable.sol";

/**
 * @title OptimizerV2
 * @notice Sentiment-driven liquidity parameter optimizer based on empirical fuzzing results.
 * @dev Replaces the original Optimizer with a mapping informed by adversarial analysis:
 *
 * Key findings from parameter sweep + Gaussian competition model:
 *
 * 1. capitalInefficiency has ZERO effect on fee revenue. It only affects floor placement.
 *    Always set to 0 for maximum safety (adjusted VWAP = 0.7× → furthest floor).
 *
 * 2. anchorShare and anchorWidth are the ONLY fee levers:
 *    - Bull: AS=100%, AW=20 → deep narrow anchor → maximizes KRK fees (which appreciate)
 *    - Bear: AS=10%, AW=100 → thin wide anchor → maximizes WETH fees + safe floor distance
 *
 * 3. The two regimes naturally align safety with fee optimization:
 *    - Bearish config is also the safest against drain attacks (AW=100 → 7000 tick clamp)
 *    - Bullish config maximizes revenue when floor safety is least needed
 *
 * Staking sentiment drives the interpolation:
 * - High staking % + low tax rate → bullish (sentiment=0) → aggressive fee capture
 * - Low staking % + high tax rate → bearish (sentiment=1e18) → defensive positioning
 */
contract OptimizerV2 is Initializable, UUPSUpgradeable {
    Kraiken private kraiken;
    Stake private stake;

    /// @dev Reverts if the caller is not the admin.
    error UnauthorizedAccount(address account);

    function initialize(address _kraiken, address _stake) public initializer {
        _changeAdmin(msg.sender);
        kraiken = Kraiken(_kraiken);
        stake = Stake(_stake);
    }

    modifier onlyAdmin() {
        _checkAdmin();
        _;
    }

    function _checkAdmin() internal view virtual {
        if (_getAdmin() != msg.sender) {
            revert UnauthorizedAccount(msg.sender);
        }
    }

    function _authorizeUpgrade(address newImplementation) internal override onlyAdmin { }

    /**
     * @notice Calculates sentiment from staking metrics.
     * @dev Reuses the V1 sentiment formula for continuity.
     *      sentiment = 0 → bullish, sentiment = 1e18 → bearish.
     */
    function calculateSentiment(uint256 averageTaxRate, uint256 percentageStaked) public pure returns (uint256 sentimentValue) {
        require(percentageStaked <= 1e18, "Invalid percentage staked");

        uint256 deltaS = 1e18 - percentageStaked;

        if (percentageStaked > 92e16) {
            uint256 penalty = (deltaS * deltaS * deltaS * averageTaxRate) / (20 * 1e48);
            sentimentValue = penalty / 2;
        } else {
            uint256 scaledStake = (percentageStaked * 1e18) / (92e16);
            uint256 baseSentiment = scaledStake >= 1e18 ? 0 : 1e18 - scaledStake;
            if (averageTaxRate <= 1e16) {
                sentimentValue = baseSentiment;
            } else if (averageTaxRate <= 5e16) {
                uint256 ratePenalty = ((averageTaxRate - 1e16) * baseSentiment) / (4e16);
                sentimentValue = baseSentiment > ratePenalty ? baseSentiment - ratePenalty : 0;
            } else {
                sentimentValue = 1e18;
            }
        }
    }

    function getSentiment() external view returns (uint256 sentiment) {
        uint256 percentageStaked = stake.getPercentageStaked();
        uint256 averageTaxRate = stake.getAverageTaxRate();
        sentiment = calculateSentiment(averageTaxRate, percentageStaked);
    }

    /**
     * @notice Returns liquidity parameters driven by staking sentiment.
     *
     * @return capitalInefficiency Always 0 — maximizes floor safety with no fee cost.
     * @return anchorShare sqrt-scaled: bull(0)=100% → bear(1e18)=10%.
     * @return anchorWidth sqrt-scaled: bull(0)=20 → bear(1e18)=100.
     * @return discoveryDepth Interpolated with sentiment (unchanged from V1).
     *
     * @dev Uses square-root response curve for ASYMMETRIC transitions:
     *      - Slow ramp to bull: requires sustained high staking to reach aggressive params
     *      - Fast snap to bear: small drops in staking cause large safety jumps
     *      Makes staking manipulation expensive: attacker must maintain >90% staking.
     */
    function getLiquidityParams() external view returns (uint256 capitalInefficiency, uint256 anchorShare, uint24 anchorWidth, uint256 discoveryDepth) {
        uint256 percentageStaked = stake.getPercentageStaked();
        uint256 averageTaxRate = stake.getAverageTaxRate();
        uint256 sentiment = calculateSentiment(averageTaxRate, percentageStaked);

        if (sentiment > 1e18) sentiment = 1e18;

        // CI = 0 always. No fee impact, maximum floor safety.
        capitalInefficiency = 0;

        // sqrt(sentiment) for aggressive bear transition:
        // sentiment=2.2% (staking=90%) → sqrtS=14.8% → already shifting defensive
        // sentiment=13%  (staking=80%) → sqrtS=36%  → well into defensive
        // sentiment=100% (staking=0%)  → sqrtS=100% → full bear
        uint256 sqrtS = Math.sqrt(sentiment * 1e18);
        // sqrtS is now in range [0, 1e18]. Scale to match sentiment range.

        // AS: 100% (bull) → 10% (bear), sqrt-scaled
        anchorShare = 1e18 - (sqrtS * 90 / 100);

        // AW: 20 (bull) → 100 (bear), sqrt-scaled
        anchorWidth = uint24(20 + (sqrtS * 80 / 1e18));

        // DD: keep sentiment-driven (V1 behavior)
        discoveryDepth = sentiment;
    }
}