// SPDX-License-Identifier: MIT
pragma solidity >=0.7.6 <0.9;

import "../../genesis/interface/IFtsoGenesis.sol";
import "../../userInterfaces/IFtso.sol";
import "../../token/interface/IIVPToken.sol";


interface IIFtso is IFtso, IFtsoGenesis {

    /// function finalizePriceReveal
    /// called by reward manager only on correct timing.
    /// if price reveal period for epoch x ended. finalize.
    /// iterate list of price submissions
    /// find weighted median
    /// find adjucant 50% of price submissions.
    /// Allocate reward for any price submission which is same as a "winning" submission
    function finalizePriceEpoch(uint256 _epochId, bool _returnRewardData) external
        returns(
            address[] memory _eligibleAddresses,
            uint256[] memory _natWeights,
            uint256 _totalNatWeight
        );

    function fallbackFinalizePriceEpoch(uint256 _epochId) external;

    function forceFinalizePriceEpoch(uint256 _epochId) external;

    // activateFtso will be called by ftso manager once ftso is added 
    // before this is done, FTSO can't run
    function activateFtso(
        uint256 _firstEpochStartTs,
        uint256 _submitPeriodSeconds,
        uint256 _revealPeriodSeconds
    ) external;

    function deactivateFtso() external;

    // update initial price and timestamp - only if not active
    function updateInitialPrice(uint256 _initialPriceUSD, uint256 _initialPriceTimestamp) external;

    function configureEpochs(
        uint256 _maxVotePowerNatThresholdFraction,
        uint256 _maxVotePowerAssetThresholdFraction,
        uint256 _lowAssetUSDThreshold,
        uint256 _highAssetUSDThreshold,
        uint256 _highAssetTurnoutThresholdBIPS,
        uint256 _lowNatTurnoutThresholdBIPS,
        address[] memory _trustedAddresses
    ) external;

    function setAsset(IIVPToken _asset) external;

    function setAssetFtsos(IIFtso[] memory _assetFtsos) external;

    // current vote power block will update per reward epoch. 
    // the FTSO doesn't have notion of reward epochs.
    // reward manager only can set this data. 
    function setVotePowerBlock(uint256 _blockNumber) external;

    function initializeCurrentEpochStateForReveal(uint256 _circulatingSupplyNat, bool _fallbackMode) external;
  
    /**
     * @notice Returns ftso manager address
     */
    function ftsoManager() external view returns (address);

    /**
     * @notice Returns the FTSO asset
     * @dev Asset is null in case of multi-asset FTSO
     */
    function getAsset() external view returns (IIVPToken);

    /**
     * @notice Returns the Asset FTSOs
     * @dev AssetFtsos is not null only in case of multi-asset FTSO
     */
    function getAssetFtsos() external view returns (IIFtso[] memory);

    /**
     * @notice Returns current configuration of epoch state
     * @return _maxVotePowerNatThresholdFraction        High threshold for native token vote power per voter
     * @return _maxVotePowerAssetThresholdFraction      High threshold for asset vote power per voter
     * @return _lowAssetUSDThreshold            Threshold for low asset vote power
     * @return _highAssetUSDThreshold           Threshold for high asset vote power
     * @return _highAssetTurnoutThresholdBIPS   Threshold for high asset turnout
     * @return _lowNatTurnoutThresholdBIPS      Threshold for low nat turnout
     * @return _trustedAddresses                Trusted addresses - use their prices if low nat turnout is not achieved
     */
    function epochsConfiguration() external view 
        returns (
            uint256 _maxVotePowerNatThresholdFraction,
            uint256 _maxVotePowerAssetThresholdFraction,
            uint256 _lowAssetUSDThreshold,
            uint256 _highAssetUSDThreshold,
            uint256 _highAssetTurnoutThresholdBIPS,
            uint256 _lowNatTurnoutThresholdBIPS,
            address[] memory _trustedAddresses
        );

    /**
     * @notice Returns parameters necessary for approximately replicating vote weighting.
     * @return _assets                  the list of Assets that are accounted in vote
     * @return _assetMultipliers        weight of each asset in (multiasset) ftso, mutiplied by TERA
     * @return _totalVotePowerNat       total native token vote power at block
     * @return _totalVotePowerAsset     total combined asset vote power at block
     * @return _assetWeightRatio        ratio of combined asset vp vs. native token vp (in BIPS)
     * @return _votePowerBlock          vote powewr block for given epoch
     */
    function getVoteWeightingParameters() external view 
        returns (
            IIVPToken[] memory _assets,
            uint256[] memory _assetMultipliers,
            uint256 _totalVotePowerNat,
            uint256 _totalVotePowerAsset,
            uint256 _assetWeightRatio,
            uint256 _votePowerBlock
        );

    function wNat() external view returns (IIVPToken);
    
    /**
     * @notice Returns current asset price calculated from trusted providers
     * @return _price               Price in USD multiplied by ASSET_PRICE_USD_DECIMALS
     * @return _timestamp           Time when price was updated for the last time
     */
    function getCurrentPriceFromTrustedProviders() external view returns (uint256 _price, uint256 _timestamp);
}