// File: contracts/DarkQuestBoard.sol



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// SPDX-License-Identifier: MIT
pragma solidity 0.8.10;

import "./oz/interfaces/IERC20.sol";
import "./oz/libraries/SafeERC20.sol";
import "./utils/Owner.sol";
import "./oz/utils/ReentrancyGuard.sol";
import "./MultiMerkleDistributor.sol";
import "./interfaces/IGaugeController.sol";
import "./utils/Errors.sol";

/** @title Warden Dark Quest Board  */
/// @author Paladin
/*
    Version of Warden Quest Board allowing to blacklist veToken voters
    And not account their Bias for rewards distribution
*/

contract DarkQuestBoard is Owner, ReentrancyGuard {
    using SafeERC20 for IERC20;

    /** @notice Address of the Curve Gauge Controller */
    address public immutable GAUGE_CONTROLLER;

    /** @notice Seconds in a Week */
    uint256 private constant WEEK = 604800;
    /** @notice 1e18 scale */
    uint256 private constant UNIT = 1e18;
    /** @notice Max BPS value (100%) */
    uint256 private constant MAX_BPS = 10000;


    /** @notice State of each Period for each Quest */
    enum PeriodState { ZERO, ACTIVE, CLOSED, DISTRIBUTED }
    // All Periods are ACTIVE at creation since they voters from past periods are also accounted for the future period


    /** @notice Struct for a Period of a Quest */
    struct QuestPeriod {
        // Total reward amount that can be distributed for that period
        uint256 rewardAmountPerPeriod;
        // Amount of reward for each vote (for 1 veCRV)
        uint256 rewardPerVote;
        // Tartget Bias for the Gauge
        uint256 objectiveVotes;
        // Amount of reward to distribute, at period closing
        uint256 rewardAmountDistributed;
        // Amount not distributed, for Quest creator to redeem
        uint256 withdrawableAmount;
        // Timestamp of the Period start
        uint48 periodStart;
        // Current state of the Period
        PeriodState currentState;
    }

    /** @notice Struct holding the parameters of the Quest common for all periods */
    struct Quest {
        // Address of the Quest creator (caller of createQuest() method)
        address creator;
        // Address of the ERC20 used for rewards
        address rewardToken;
        // Address of the target Gauge
        address gauge;
        // Total number of periods for the Quest
        uint48 duration;
        // Timestamp where the 1st QuestPeriod starts
        uint48 periodStart;
        // Total amount of rewards paid for this Quest
        // If changes were made to the parameters of this Quest, this will account
        // any added reward amounts
        uint256 totalRewardAmount;
    }

    /** @notice ID for the next Quest to be created */
    uint256 public nextID;

    /** @notice List of Quest (indexed by ID) */
    // ID => Quest
    mapping(uint256 => Quest) public quests;
    /** @notice List of timestamp periods the Quest is active in */
    // QuestID => Periods (timestamps)
    mapping(uint256 => uint48[]) public questPeriods;
    /** @notice Mapping of all QuestPeriod struct for each period of each Quest */
    // QuestID => period => QuestPeriod
    mapping(uint256 => mapping(uint256 => QuestPeriod)) public periodsByQuest;
    /** @notice All the Quests present in this period */
    // period => array of Quest
    mapping(uint256 => uint256[]) public questsByPeriod;
    /** @notice Mapping of Distributors used by each Quest to send rewards */
    // ID => Distributor
    mapping(uint256 => address) public questDistributors;
    /** @notice Mapping of blacklisted voters for each Quest */
    // ID => Blacklist
    mapping(uint256 => address[]) public questBlacklist;


    /** @notice Platform fees ratio (in BPS) */
    uint256 public platformFee = 500;

    /** @notice Minimum Objective required */
    uint256 public minObjective;

    /** @notice Address of the Chest to receive platform fees */
    address public questChest;
    /** @notice Address of the reward Distributor contract */
    address public distributor;

    /** @notice Mapping of addresses allowed to call manager methods */
    mapping(address => bool) approvedManagers;
    /** @notice Whitelisted tokens that can be used as reward tokens */
    mapping(address => bool) public whitelistedTokens;
    /** @notice Min rewardPerVote per token (to avoid spam creation of useless Quest) */
    mapping(address => uint256) public minRewardPerVotePerToken;

    /** @notice Boolean, true if the cotnract was killed, stopping main user functions */
    bool public isKilled;
    /** @notice Timestam pwhen the contract was killed */
    uint256 public kill_ts;
    /** @notice Delay where contract can be unkilled */
    uint256 public constant KILL_DELAY = 2 * 604800; //2 weeks

    // Events

    /** @notice Event emitted when a new Quest is created */
    event NewQuest(
        uint256 indexed questID,
        address indexed creator,
        address indexed gauge,
        address rewardToken,
        uint48 duration,
        uint256 startPeriod,
        uint256 objectiveVotes,
        uint256 rewardPerVote
    );

    /** @notice Event emitted when rewards of a Quest are increased */
    event IncreasedQuestReward(uint256 indexed questID, uint256 indexed updatePeriod, uint256 newRewardPerVote, uint256 addedRewardAmount);
    /** @notice Event emitted when the Quest objective bias is increased */
    event IncreasedQuestObjective(uint256 indexed questID, uint256 indexed updatePeriod, uint256 newObjective, uint256 addedRewardAmount);
    /** @notice Event emitted when the Quest duration is extended */
    event IncreasedQuestDuration(uint256 indexed questID, uint256 addedDuration, uint256 addedRewardAmount);

    /** @notice Event emitted when Quest creator withdraw undistributed rewards */
    event WithdrawUnusedRewards(uint256 indexed questID, address recipient, uint256 amount);

    /** @notice Event emitted when a Period is Closed */
    event PeriodClosed(uint256 indexed questID, uint256 indexed period);

    event PeriodBiasFixed(uint256 indexed questID, uint256 indexed period, uint256 newBias);

    event AddVoterBlacklist(uint256 indexed questID, address indexed account);
    event RemoveVoterBlacklist(uint256 indexed questID, address indexed account);

    /** @notice Event emitted when a new reward token is whitelisted */
    event WhitelistToken(address indexed token, uint256 minRewardPerVote);
    event UpdateRewardToken(address indexed token, uint256 newMinRewardPerVote);

    /** @notice Event emitted when the contract is killed */
    event Killed(uint256 killTime);
    /** @notice Event emitted when the contract is unkilled */
    event Unkilled(uint256 unkillTime);
    /** @notice Event emitted when the Quest creator withdraw all unused funds (if the contract was killed) */
    event EmergencyWithdraw(uint256 indexed questID, address recipient, uint256 amount);

    event InitDistributor(address distributor);
    event ApprovedManager(address indexed manager);
    event RemovedManager(address indexed manager);
    event ChestUpdated(address oldChest, address newChest);
    event DistributorUpdated(address oldDistributor, address newDistributor);
    event PlatformFeeUpdated(uint256 oldfee, uint256 newFee);
    event MinObjectiveUpdated(uint256 oldMinObjective, uint256 newMinObjective);

    // Modifiers

    /** @notice Check the caller is either the admin or an approved manager */
    modifier onlyAllowed(){
        if(!approvedManagers[msg.sender] && msg.sender != owner()) revert Errors.CallerNotAllowed();
        _;
    }

    /** @notice Check that contract was not killed */
    modifier isAlive(){
        if(isKilled) revert Errors.Killed();
        _;
    }


    // Constructor
    constructor(address _gaugeController, address _chest){
        if(_gaugeController == address(0)) revert Errors.ZeroAddress();
        if(_chest == address(0)) revert Errors.ZeroAddress();
        if(_gaugeController == _chest) revert Errors.SameAddress();


        GAUGE_CONTROLLER = _gaugeController;

        questChest = _chest;

        minObjective = 1000 * UNIT;
    }


    // View Functions
   
    /**
    * @notice Returns the current Period for the contract
    * @dev Returns the current Period for the contract
    */
    function getCurrentPeriod() public view returns(uint256) {
        return (block.timestamp / WEEK) * WEEK;
    }
   
    /**
    * @notice Returns the list of all Quest IDs active on a given period
    * @dev Returns the list of all Quest IDs active on a given period
    * @param period Timestamp of the period
    * @return uint256[] : Quest IDs for the period
    */
    function getQuestIdsForPeriod(uint256 period) external view returns(uint256[] memory) {
        period = (period / WEEK) * WEEK;
        return questsByPeriod[period];
    }
   
    /**
    * @notice Returns all periods for a Quest
    * @dev Returns all period timestamps for a Quest ID
    * @param questId ID of the Quest
    * @return uint256[] : List of period timestamps
    */
    function getAllPeriodsForQuestId(uint256 questId) external view returns(uint48[] memory) {
        return questPeriods[questId];
    }
   
    /**
    * @notice Returns all QuestPeriod of a given Quest
    * @dev Returns all QuestPeriod of a given Quest ID
    * @param questId ID of the Quest
    * @return QuestPeriod[] : list of QuestPeriods
    */
    function getAllQuestPeriodsForQuestId(uint256 questId) external view returns(QuestPeriod[] memory) {
        uint256 nbPeriods = questPeriods[questId].length;
        QuestPeriod[] memory periods = new QuestPeriod[](nbPeriods);
        for(uint256 i; i < nbPeriods;){
            periods[i] = periodsByQuest[questId][questPeriods[questId][i]];
            unchecked{ ++i; }
        }
        return periods;
    }
   
    /**
    * @dev Returns the number of periods to come for a given Quest
    * @param questID ID of the Quest
    * @return uint : remaining duration (non active periods)
    */
    function _getRemainingDuration(uint256 questID) internal view returns(uint256) {
        // Since we have the current period, the start period for the Quest, and each period is 1 WEEK
        // We can find the number of remaining periods in the Quest simply by dividing the remaining time between
        // currentPeriod and the last QuestPeriod start by a WEEK.
        // If the current period is the last period of the Quest, we want to return 0
        if(questPeriods[questID].length == 0) revert Errors.EmptyQuest();
        uint256 lastPeriod = questPeriods[questID][questPeriods[questID].length - 1];
        uint256 currentPeriod = getCurrentPeriod();
        return lastPeriod < currentPeriod ? 0: (lastPeriod - currentPeriod) / WEEK;
    }

    function getCurrentReducedBias(uint256 questID) external view returns(uint256) {
        uint256 nextPeriod = getCurrentPeriod() + WEEK;

        IGaugeController gaugeController = IGaugeController(GAUGE_CONTROLLER);

        address gauge = quests[questID].gauge;

        // Get the bias of the Gauge for the end of the period
        uint256 periodBias = gaugeController.points_weight(gauge, nextPeriod).bias;
        uint256 reducedBias = _getGaugeReducedBias(questID, gauge, nextPeriod);
        uint256 periodAdjustedBias = reducedBias >= periodBias ? 0 : periodBias - reducedBias;

        return periodAdjustedBias;
    }

    function getQuestBlacklsit(uint256 questID) external view returns(address[] memory){
        return questBlacklist[questID];
    }


    // Functions


    struct CreateVars {
        address creator;
        uint256 rewardPerPeriod;
        uint256 nextPeriod;
        uint256 periodIterator;
    }
   
    /**
    * @notice Creates a new Quest
    * @dev Creates a new Quest struct, and QuestPeriods for the Quest duration
    * @param gauge Address of the Gauge targeted by the Quest
    * @param rewardToken Address of the reward token
    * @param duration Duration (in number of periods) of the Quest
    * @param objective Target bias to reach (equivalent to amount of veCRV in wei to reach)
    * @param rewardPerVote Amount of reward per veCRV (in wei)
    * @param totalRewardAmount Total amount of rewards for the whole Quest (in wei)
    * @param feeAmount Platform fees amount (in wei)
    * @return uint256 : ID of the newly created Quest
    */
    function createQuest(
        address gauge,
        address rewardToken,
        uint48 duration,
        uint256 objective,
        uint256 rewardPerVote,
        uint256 totalRewardAmount,
        uint256 feeAmount,
        address[] calldata blacklist
    ) external isAlive nonReentrant returns(uint256) {
        if(distributor == address(0)) revert Errors.NoDistributorSet();
        // Local memory variables
        CreateVars memory vars;
        vars.creator = msg.sender;

        // Check all parameters
        if(gauge == address(0) || rewardToken == address(0)) revert Errors.ZeroAddress();
        if(IGaugeController(GAUGE_CONTROLLER).gauge_types(gauge) < 0) revert Errors.InvalidGauge();
        if(!whitelistedTokens[rewardToken]) revert Errors.TokenNotWhitelisted();
        if(duration == 0) revert Errors.IncorrectDuration();
        if(objective < minObjective) revert Errors.ObjectiveTooLow();
        if(rewardPerVote == 0 || totalRewardAmount == 0 || feeAmount == 0) revert Errors.NullAmount();
        if(rewardPerVote < minRewardPerVotePerToken[rewardToken]) revert Errors.RewardPerVoteTooLow();

        // Verifiy the given amounts of reward token are correct
        vars.rewardPerPeriod = (objective * rewardPerVote) / UNIT;

        if((vars.rewardPerPeriod * duration) != totalRewardAmount) revert Errors.IncorrectTotalRewardAmount();
        if((totalRewardAmount * platformFee)/MAX_BPS != feeAmount) revert Errors.IncorrectFeeAmount();

        // Pull all the rewards in this contract
        IERC20(rewardToken).safeTransferFrom(vars.creator, address(this), totalRewardAmount);
        // And transfer the fees from the Quest creator to the Chest contract
        IERC20(rewardToken).safeTransferFrom(vars.creator, questChest, feeAmount);

        // Quest will start on next period
        vars.nextPeriod = getCurrentPeriod() + WEEK;

        // Get the ID for that new Quest and increment the nextID counter
        uint256 newQuestID = nextID;
        unchecked{ ++nextID; }

        // Fill the Quest struct data
        quests[newQuestID].creator = vars.creator;
        quests[newQuestID].rewardToken = rewardToken;
        quests[newQuestID].gauge = gauge;
        quests[newQuestID].duration = duration;
        quests[newQuestID].totalRewardAmount = totalRewardAmount;
        quests[newQuestID].periodStart = safe48(vars.nextPeriod);

        //Set the current Distributor as the one to receive the rewards for users for that Quest
        questDistributors[newQuestID] = distributor;

        // Iterate on periods based on Quest duration
        vars.periodIterator = vars.nextPeriod;
        for(uint256 i; i < duration;){
            // Add the Quest on the list of Quests active on the period
            questsByPeriod[vars.periodIterator].push(newQuestID);

            // And add the period in the list of periods of the Quest
            questPeriods[newQuestID].push(safe48(vars.periodIterator));

            periodsByQuest[newQuestID][vars.periodIterator].periodStart = safe48(vars.periodIterator);
            periodsByQuest[newQuestID][vars.periodIterator].objectiveVotes = objective;
            periodsByQuest[newQuestID][vars.periodIterator].rewardPerVote = rewardPerVote;
            periodsByQuest[newQuestID][vars.periodIterator].rewardAmountPerPeriod = vars.rewardPerPeriod;
            periodsByQuest[newQuestID][vars.periodIterator].currentState = PeriodState.ACTIVE;
            // Rest of the struct shoud laready have the correct base data:
            // rewardAmountDistributed => 0
            // withdrawableAmount => 0

            vars.periodIterator = ((vars.periodIterator + WEEK) / WEEK) * WEEK;

            unchecked{ ++i; }
        }

        // Set the blacklsit for this Quest
        _setQuestBlacklist(newQuestID, blacklist);

        // Add that Quest & the reward token in the Distributor
        if(!MultiMerkleDistributor(distributor).addQuest(newQuestID, rewardToken)) revert Errors.DisitributorFail();

        emit NewQuest(
            newQuestID,
            vars.creator,
            gauge,
            rewardToken,
            duration,
            vars.nextPeriod,
            objective,
            rewardPerVote
        );

        return newQuestID;
    }

   
    /**
    * @notice Increases the duration of a Quest
    * @dev Adds more QuestPeriods and extends the duration of a Quest
    * @param questID ID of the Quest
    * @param addedDuration Number of period to add
    * @param addedRewardAmount Amount of reward to add for the new periods (in wei)
    * @param feeAmount Platform fees amount (in wei)
    */
    function increaseQuestDuration(
        uint256 questID,
        uint48 addedDuration,
        uint256 addedRewardAmount,
        uint256 feeAmount
    ) external isAlive nonReentrant {
        if(questID >= nextID) revert Errors.InvalidQuestID();
        if(msg.sender != quests[questID].creator) revert Errors.CallerNotAllowed();
        if(addedRewardAmount == 0 || feeAmount == 0) revert Errors.NullAmount();
        if(addedDuration == 0) revert Errors.IncorrectAddDuration();

        //We take data from the last period of the Quest to account for any other changes in the Quest parameters
        if(questPeriods[questID].length == 0) revert Errors.EmptyQuest();
        uint256 lastPeriod = questPeriods[questID][questPeriods[questID].length - 1];

        if(lastPeriod < getCurrentPeriod()) revert Errors.ExpiredQuest();

        // Check that the given amounts are correct
        uint rewardPerPeriod = periodsByQuest[questID][lastPeriod].rewardAmountPerPeriod;

        if((rewardPerPeriod * addedDuration) != addedRewardAmount) revert Errors.IncorrectAddedRewardAmount();
        if((addedRewardAmount * platformFee)/MAX_BPS != feeAmount) revert Errors.IncorrectFeeAmount();

        address rewardToken = quests[questID].rewardToken;
        // Pull all the rewards in this contract
        IERC20(rewardToken).safeTransferFrom(msg.sender, address(this), addedRewardAmount);
        // And transfer the fees from the Quest creator to the Chest contract
        IERC20(rewardToken).safeTransferFrom(msg.sender, questChest, feeAmount);

        uint256 periodIterator = ((lastPeriod + WEEK) / WEEK) * WEEK;

        // Update the Quest struct with added reward admounts & added duration
        quests[questID].totalRewardAmount += addedRewardAmount;
        quests[questID].duration += addedDuration;

        uint256 objective = periodsByQuest[questID][lastPeriod].objectiveVotes;
        uint256 rewardPerVote = periodsByQuest[questID][lastPeriod].rewardPerVote;

        // Add QuestPeriods for the new added duration
        for(uint256 i; i < addedDuration;){
            questsByPeriod[periodIterator].push(questID);

            questPeriods[questID].push(safe48(periodIterator));

            periodsByQuest[questID][periodIterator].periodStart = safe48(periodIterator);
            periodsByQuest[questID][periodIterator].objectiveVotes = objective;
            periodsByQuest[questID][periodIterator].rewardPerVote = rewardPerVote;
            periodsByQuest[questID][periodIterator].rewardAmountPerPeriod = rewardPerPeriod;
            periodsByQuest[questID][periodIterator].currentState = PeriodState.ACTIVE;
            // Rest of the struct shoud laready have the correct base data:
            // rewardAmountDistributed => 0
            // redeemableAmount => 0

            periodIterator = ((periodIterator + WEEK) / WEEK) * WEEK;

            unchecked{ ++i; }
        }

        emit IncreasedQuestDuration(questID, addedDuration, addedRewardAmount);

    }
   
    /**
    * @notice Increases the reward per votes for a Quest
    * @dev Increases the reward per votes for a Quest
    * @param questID ID of the Quest
    * @param newRewardPerVote New amount of reward per veCRV (in wei)
    * @param addedRewardAmount Amount of rewards to add (in wei)
    * @param feeAmount Platform fees amount (in wei)
    */
    function increaseQuestReward(
        uint256 questID,
        uint256 newRewardPerVote,
        uint256 addedRewardAmount,
        uint256 feeAmount
    ) external isAlive nonReentrant {
        if(questID >= nextID) revert Errors.InvalidQuestID();
        if(msg.sender != quests[questID].creator) revert Errors.CallerNotAllowed();
        if(newRewardPerVote == 0 || addedRewardAmount == 0 || feeAmount == 0) revert Errors.NullAmount();
    
        uint256 remainingDuration = _getRemainingDuration(questID); //Also handles the Empty Quest check
        if(remainingDuration == 0) revert Errors.ExpiredQuest();

        // The new reward amount must be higher 
        uint256 nextPeriod = getCurrentPeriod() + WEEK;
        if(newRewardPerVote <= periodsByQuest[questID][nextPeriod].rewardPerVote) revert Errors.LowerRewardPerVote();

        // For all non active QuestPeriods (non Closed, nor the current Active one)
        // Calculates the amount of reward token needed with the new rewardPerVote value
        // by calculating the new amount of reward per period, and the difference with the current amount of reward per period
        // to have the exact amount to add for each non-active period, and the exact total amount to add to the Quest
        // (because we don't want to pay for Periods that are Closed or the current period)
        uint256 newRewardPerPeriod = (periodsByQuest[questID][nextPeriod].objectiveVotes * newRewardPerVote) / UNIT;
        uint256 diffRewardPerPeriod = newRewardPerPeriod - periodsByQuest[questID][nextPeriod].rewardAmountPerPeriod;

        if((diffRewardPerPeriod * remainingDuration) != addedRewardAmount) revert Errors.IncorrectAddedRewardAmount();
        if((addedRewardAmount * platformFee)/MAX_BPS != feeAmount) revert Errors.IncorrectFeeAmount();

        address rewardToken = quests[questID].rewardToken;
        // Pull all the rewards in this contract
        IERC20(rewardToken).safeTransferFrom(msg.sender, address(this), addedRewardAmount);
        // And transfer the fees from the Quest creator to the Chest contract
        IERC20(rewardToken).safeTransferFrom(msg.sender, questChest, feeAmount);

        uint256 periodIterator = nextPeriod;

        uint256 lastPeriod = questPeriods[questID][questPeriods[questID].length - 1];

        // Update the Quest struct with the added reward amount
        quests[questID].totalRewardAmount += addedRewardAmount;

        // Update all QuestPeriods, starting with the nextPeriod one
        for(uint256 i; i < remainingDuration;){

            if(periodIterator > lastPeriod) break; //Safety check, we never want to write on non-initialized QuestPeriods (that were not initialized)

            // And update each QuestPeriod with the new values
            periodsByQuest[questID][periodIterator].rewardPerVote = newRewardPerVote;
            periodsByQuest[questID][periodIterator].rewardAmountPerPeriod = newRewardPerPeriod;

            periodIterator = ((periodIterator + WEEK) / WEEK) * WEEK;

            unchecked{ ++i; }
        }

        emit IncreasedQuestReward(questID, nextPeriod, newRewardPerVote, addedRewardAmount);
    }
   
    /**
    * @notice Increases the target bias/veCRV amount to reach on the Gauge
    * @dev CIncreases the target bias/veCRV amount to reach on the Gauge
    * @param questID ID of the Quest
    * @param newObjective New target bias to reach (equivalent to amount of veCRV in wei to reach)
    * @param addedRewardAmount Amount of rewards to add (in wei)
    * @param feeAmount Platform fees amount (in wei)
    */
    function increaseQuestObjective(
        uint256 questID,
        uint256 newObjective,
        uint256 addedRewardAmount,
        uint256 feeAmount
    ) external isAlive nonReentrant {
        if(questID >= nextID) revert Errors.InvalidQuestID();
        if(msg.sender != quests[questID].creator) revert Errors.CallerNotAllowed();
        if(addedRewardAmount == 0 || feeAmount == 0) revert Errors.NullAmount();
    
        uint256 remainingDuration = _getRemainingDuration(questID); //Also handles the Empty Quest check
        if(remainingDuration == 0) revert Errors.ExpiredQuest();

        // No need to compare to minObjective : the new value must be higher than current Objective
        // and current objective needs to be >= minObjective
        uint256 nextPeriod = getCurrentPeriod() + WEEK;
        if(newObjective <= periodsByQuest[questID][nextPeriod].objectiveVotes) revert Errors.LowerObjective();

        // For all non active QuestPeriods (non Closed, nor the current Active one)
        // Calculates the amount of reward token needed with the new objective bias
        // by calculating the new amount of reward per period, and the difference with the current amount of reward per period
        // to have the exact amount to add for each non-active period, and the exact total amount to add to the Quest
        // (because we don't want to pay for Periods that are Closed or the current period)
        uint256 newRewardPerPeriod = (newObjective * periodsByQuest[questID][nextPeriod].rewardPerVote) / UNIT;
        uint256 diffRewardPerPeriod = newRewardPerPeriod - periodsByQuest[questID][nextPeriod].rewardAmountPerPeriod;

        if((diffRewardPerPeriod * remainingDuration) != addedRewardAmount) revert Errors.IncorrectAddedRewardAmount();
        if((addedRewardAmount * platformFee)/MAX_BPS != feeAmount) revert Errors.IncorrectFeeAmount();

        address rewardToken = quests[questID].rewardToken;
        // Pull all the rewards in this contract
        IERC20(rewardToken).safeTransferFrom(msg.sender, address(this), addedRewardAmount);
        // And transfer the fees from the Quest creator to the Chest contract
        IERC20(rewardToken).safeTransferFrom(msg.sender, questChest, feeAmount);


        uint256 periodIterator = nextPeriod;

        uint256 lastPeriod = questPeriods[questID][questPeriods[questID].length - 1];

        // Update the Quest struct with the added reward amount
        quests[questID].totalRewardAmount += addedRewardAmount;

        // Update all QuestPeriods, starting with the nextPeriod one
        for(uint256 i; i < remainingDuration;){

            if(periodIterator > lastPeriod) break; //Safety check, we never want to write on non-existing QuestPeriods (that were not initialized)

            // And update each QuestPeriod with the new values
            periodsByQuest[questID][periodIterator].objectiveVotes = newObjective;
            periodsByQuest[questID][periodIterator].rewardAmountPerPeriod = newRewardPerPeriod;

            periodIterator = ((periodIterator + WEEK) / WEEK) * WEEK;

            unchecked{ ++i; }
        }

        emit IncreasedQuestObjective(questID, nextPeriod, newObjective, addedRewardAmount);
    }
   
    /**
    * @notice Withdraw all undistributed rewards from Closed Quest Periods
    * @dev Withdraw all undistributed rewards from Closed Quest Periods
    * @param questID ID of the Quest
    * @param recipient Address to send the reward tokens to
    */
    function withdrawUnusedRewards(uint256 questID, address recipient) external isAlive nonReentrant {
        if(questID >= nextID) revert Errors.InvalidQuestID();
        if(msg.sender != quests[questID].creator) revert Errors.CallerNotAllowed();
        if(recipient == address(0)) revert Errors.ZeroAddress();

        // Total amount available to withdraw
        uint256 totalWithdraw;

        uint48[] memory _questPeriods = questPeriods[questID];

        uint256 length = _questPeriods.length;
        for(uint256 i; i < length;){
            QuestPeriod storage _questPeriod = periodsByQuest[questID][_questPeriods[i]];

            // We allow to withdraw unused rewards after the period was closed, or after it was distributed
            if(_questPeriod.currentState == PeriodState.ACTIVE) {
                unchecked{ ++i; }
                continue;
            }

            uint256 withdrawableForPeriod = _questPeriod.withdrawableAmount;

            // If there is token to withdraw for that period, add they to the total to withdraw,
            // and set the withdrawable amount to 0
            if(withdrawableForPeriod != 0){
                totalWithdraw += withdrawableForPeriod;
                _questPeriod.withdrawableAmount = 0;
            }

            unchecked{ ++i; }
        }

        // If there is a non null amount of token to withdraw, execute a transfer
        if(totalWithdraw != 0){
            address rewardToken = quests[questID].rewardToken;
            IERC20(rewardToken).safeTransfer(recipient, totalWithdraw);

            emit WithdrawUnusedRewards(questID, recipient, totalWithdraw);
        }
    }
   
    /**
    * @notice Emergency withdraws all undistributed rewards from Closed Quest Periods & all rewards for Active Periods
    * @dev Emergency withdraws all undistributed rewards from Closed Quest Periods & all rewards for Active Periods
    * @param questID ID of the Quest
    * @param recipient Address to send the reward tokens to
    */
    function emergencyWithdraw(uint256 questID, address recipient) external nonReentrant {
        if(!isKilled) revert Errors.NotKilled();
        if(block.timestamp < kill_ts + KILL_DELAY) revert Errors.KillDelayNotExpired();

        if(questID >= nextID) revert Errors.InvalidQuestID();
        if(msg.sender != quests[questID].creator) revert Errors.CallerNotAllowed();
        if(recipient == address(0)) revert Errors.ZeroAddress();

        // Total amount to emergency withdraw
        uint256 totalWithdraw;

        uint48[] memory _questPeriods = questPeriods[questID];
        uint256 length = _questPeriods.length;
        for(uint256 i; i < length;){
            QuestPeriod storage _questPeriod = periodsByQuest[questID][_questPeriods[i]];

            // For CLOSED or DISTRIBUTED periods
            if(_questPeriod.currentState != PeriodState.ACTIVE){
                uint256 withdrawableForPeriod = _questPeriod.withdrawableAmount;

                // If there is a non_null withdrawable amount for the period,
                // add it to the total to withdraw, et set the withdrawable amount ot 0
                if(withdrawableForPeriod != 0){
                    totalWithdraw += withdrawableForPeriod;
                    _questPeriod.withdrawableAmount = 0;
                }
            } else {
                // And for the active period, and the next ones, withdraw the total reward amount
                totalWithdraw += _questPeriod.rewardAmountPerPeriod;
                _questPeriod.rewardAmountPerPeriod = 0;
            }

            unchecked{ ++i; }
        }

        // If the total amount to emergency withdraw is non_null, execute a transfer
        if(totalWithdraw != 0){
            address rewardToken = quests[questID].rewardToken;
            IERC20(rewardToken).safeTransfer(recipient, totalWithdraw);

            emit EmergencyWithdraw(questID, recipient, totalWithdraw);
        }

    }


    function _addToBlacklist(uint256 questID, address account) internal {
        //We don't want to have 2x the same address in the list
        address[] memory _list = questBlacklist[questID];
        uint256 length = _list.length;
        for(uint256 i; i < length;){
            if(_list[i] == account) revert Errors.AlreadyBlacklisted();
            unchecked {
                ++i;
            }
        }

        questBlacklist[questID].push(account);

        emit AddVoterBlacklist(questID, account);
    }

    function _removeFromBlacklist(uint256 questID, address account) internal {
        address[] memory _list = questBlacklist[questID];
        uint256 length = _list.length;

        for(uint256 i; i < length;){
            if(_list[i] == account){
                if(i != length - 1){
                    questBlacklist[questID][i] = _list[length - 1];
                }
                questBlacklist[questID].pop();

                emit RemoveVoterBlacklist(questID, account);

                return;
            }

            unchecked {
                ++i;
            }
        }
    }

    function _setQuestBlacklist(uint256 questID, address[] calldata accounts) internal {
        uint256 length = accounts.length;

        for(uint256 i; i < length;){
            if(accounts[i] == address(0)) revert Errors.ZeroAddress();

            _addToBlacklist(questID, accounts[i]);

            unchecked {
                ++i;
            }
        }
    }

    function addToBlacklist(uint256 questID, address account) external isAlive nonReentrant {
        if(questID >= nextID) revert Errors.InvalidQuestID();
        if(msg.sender != quests[questID].creator) revert Errors.CallerNotAllowed();
        if(account == address(0)) revert Errors.ZeroAddress();

        if(questPeriods[questID].length == 0) revert Errors.EmptyQuest();
        uint256 lastPeriod = questPeriods[questID][questPeriods[questID].length - 1];
        if(getCurrentPeriod() > lastPeriod) revert Errors.ExpiredQuest();

        _addToBlacklist(questID, account);
    }

    function addMultipleToBlacklist(uint256 questID, address[] calldata accounts) external isAlive nonReentrant {
        if(questID >= nextID) revert Errors.InvalidQuestID();
        if(msg.sender != quests[questID].creator) revert Errors.CallerNotAllowed();

        if(questPeriods[questID].length == 0) revert Errors.EmptyQuest();
        uint256 lastPeriod = questPeriods[questID][questPeriods[questID].length - 1];
        if(getCurrentPeriod() > lastPeriod) revert Errors.ExpiredQuest();

        uint256 length = accounts.length;

        for(uint256 i = 0; i < length;){
            if(accounts[i] == address(0)) revert Errors.ZeroAddress();

            _addToBlacklist(questID, accounts[i]);

            unchecked {
                ++i;
            }
        }
    }

    function removeFromBlacklist(uint256 questID, address account) external isAlive nonReentrant {
        if(questID >= nextID) revert Errors.InvalidQuestID();
        if(msg.sender != quests[questID].creator) revert Errors.CallerNotAllowed();
        if(account == address(0)) revert Errors.ZeroAddress();

        if(questPeriods[questID].length == 0) revert Errors.EmptyQuest();
        uint256 lastPeriod = questPeriods[questID][questPeriods[questID].length - 1];
        if(getCurrentPeriod() > lastPeriod) revert Errors.ExpiredQuest();

        _removeFromBlacklist(questID, account);
    }


    // Manager functions

    function _getVoterBias(address gauge, address voter, uint256 period) internal view returns(uint256 userBias) {
        IGaugeController gaugeController = IGaugeController(GAUGE_CONTROLLER);
        uint256 lastUserVote = gaugeController.last_user_vote(voter, gauge);
        IGaugeController.VotedSlope memory voteUserSlope = gaugeController.vote_user_slopes(voter, gauge);

        if(lastUserVote > period) return 0;
        if(voteUserSlope.end <= period) return 0;
        if(voteUserSlope.slope == 0) return 0;

        userBias = voteUserSlope.slope * (voteUserSlope.end - period);
    }

    function _getGaugeReducedBias(uint256 questID, address gauge, uint256 period) internal view returns(uint256 reducedBias) {
        address[] memory _votersBlacklsit = questBlacklist[questID];

        uint256 length = _votersBlacklsit.length;
        for(uint256 i = 0; i < length;){
            
            reducedBias += _getVoterBias(gauge, _votersBlacklsit[i], period);

            unchecked {
                ++i;
            }
        }
    }

    function _closeQuestPeriod(uint256 period, uint256 questID) internal returns(bool) {
        // We check that this period was not already closed
        if(periodsByQuest[questID][period].currentState != PeriodState.ACTIVE) return false;
            
        // We use the Gauge Point data from nextPeriod => the end of the period we are closing
        uint256 nextPeriod = period + WEEK;

        IGaugeController gaugeController = IGaugeController(GAUGE_CONTROLLER);

        Quest memory _quest = quests[questID];
        QuestPeriod memory _questPeriod = periodsByQuest[questID][period];
        _questPeriod.currentState = PeriodState.CLOSED;

        // Call a checkpoint on the Gauge, in case it was not written yet
        gaugeController.checkpoint_gauge(_quest.gauge);

        // Get the bias of the Gauge for the end of the period
        uint256 periodBias = gaugeController.points_weight(_quest.gauge, nextPeriod).bias;
        uint256 reducedBias = _getGaugeReducedBias(questID, _quest.gauge, nextPeriod);
        uint256 periodAdjustedBias = reducedBias >= periodBias ? 0 : periodBias - reducedBias;

        if(periodAdjustedBias == 0) { 
            //Because we don't want to divide by 0
            // Here since the bias is 0, we consider 0% completion
            // => no rewards to be distributed
            // We do not change _questPeriod.rewardAmountDistributed since the default value is already 0
            _questPeriod.withdrawableAmount = _questPeriod.rewardAmountPerPeriod;
        }
        else{
            // For here, if the Gauge Bias is equal or greater than the objective, 
            // set all the period reward to be distributed.
            // If the bias is less, we take that bias, and calculate the amount of rewards based
            // on the rewardPerVote & the Gauge bias

            uint256 toDistributeAmount = periodAdjustedBias >= _questPeriod.objectiveVotes ? _questPeriod.rewardAmountPerPeriod : (periodAdjustedBias * _questPeriod.rewardPerVote) / UNIT;

            _questPeriod.rewardAmountDistributed = toDistributeAmount;
            // And the rest is set as withdrawable amount, that the Quest creator can retrieve
            _questPeriod.withdrawableAmount = _questPeriod.rewardAmountPerPeriod - toDistributeAmount;

            address questDistributor = questDistributors[questID];
            if(!MultiMerkleDistributor(questDistributor).addQuestPeriod(questID, period, toDistributeAmount)) revert Errors.DisitributorFail();
            IERC20(_quest.rewardToken).safeTransfer(questDistributor, toDistributeAmount);
        }

        periodsByQuest[questID][period] =  _questPeriod;

        emit PeriodClosed(questID, period);

        return true;
    }
 
    /**
    * @notice Closes the Period, and all QuestPeriods for this period
    * @dev Closes all QuestPeriod for the given period, calculating rewards to distribute & send them to distributor
    * @param period Timestamp of the period
    */
    function closeQuestPeriod(uint256 period) external isAlive onlyAllowed nonReentrant returns(uint256 closed, uint256 skipped) {
        period = (period / WEEK) * WEEK;
        if(distributor == address(0)) revert Errors.NoDistributorSet();
        if(period == 0) revert Errors.InvalidPeriod();
        if(period >= getCurrentPeriod()) revert Errors.PeriodStillActive();
        if(questsByPeriod[period].length == 0) revert Errors.EmptyPeriod();
        // We use the 1st QuestPeriod of this period to check it was not Closed
        uint256[] memory questsForPeriod = questsByPeriod[period];

        // For each QuestPeriod
        uint256 length = questsForPeriod.length;
        for(uint256 i = 0; i < length;){
            bool result = _closeQuestPeriod(period, questsForPeriod[i]);

            if(result){
                closed++;
            } 
            else {
                skipped++;
            }

            unchecked{ ++i; }
        }
    }

    /**
    * @notice Closes the given QuestPeriods for the Period
    * @dev Closes the given QuestPeriods for the Period, calculating rewards to distribute & send them to distributor
    * @param period Timestamp of the period
    * @param questIDs List of the Quest IDs to close
    */
    function closePartOfQuestPeriod(uint256 period, uint256[] calldata questIDs) external isAlive onlyAllowed nonReentrant returns(uint256 closed, uint256 skipped) {
        period = (period / WEEK) * WEEK;
        uint256 questIDLength = questIDs.length;
        if(questIDLength == 0) revert Errors.EmptyArray();
        if(distributor == address(0)) revert Errors.NoDistributorSet();
        if(period == 0) revert Errors.InvalidPeriod();
        if(period >= getCurrentPeriod()) revert Errors.PeriodStillActive();
        if(questsByPeriod[period].length == 0) revert Errors.EmptyPeriod();

        // For each QuestPeriod
        for(uint256 i = 0; i < questIDLength;){
            bool result = _closeQuestPeriod(period, questIDs[i]);

            if(result){
                closed++;
            } 
            else {
                skipped++;
            }

            unchecked{ ++i; }
        }
    }
   
    /**
    * @dev Sets the QuestPeriod as disitrbuted, and adds the MerkleRoot to the Distributor contract
    * @param questID ID of the Quest
    * @param period Timestamp of the period
    * @param totalAmount sum of all rewards for the Merkle Tree
    * @param merkleRoot MerkleRoot to add
    */
    function _addMerkleRoot(uint256 questID, uint256 period, uint256 totalAmount, bytes32 merkleRoot) internal {
        if(questID >= nextID) revert Errors.InvalidQuestID();
        if(merkleRoot == 0) revert Errors.EmptyMerkleRoot();
        if(totalAmount == 0) revert Errors.NullAmount();

        // This also allows to check if the given period is correct => If not, the currentState is never set to CLOSED for the QuestPeriod
        if(periodsByQuest[questID][period].currentState != PeriodState.CLOSED) revert Errors.PeriodNotClosed();

        // Add the MerkleRoot to the Distributor & set the QuestPeriod as DISTRIBUTED
        if(!MultiMerkleDistributor(questDistributors[questID]).updateQuestPeriod(questID, period, totalAmount, merkleRoot)) revert Errors.DisitributorFail();

        periodsByQuest[questID][period].currentState = PeriodState.DISTRIBUTED;
    }
   
    /**
    * @notice Sets the QuestPeriod as disitrbuted, and adds the MerkleRoot to the Distributor contract
    * @dev internal call to _addMerkleRoot()
    * @param questID ID of the Quest
    * @param period Timestamp of the period
    * @param totalAmount sum of all rewards for the Merkle Tree
    * @param merkleRoot MerkleRoot to add
    */
    function addMerkleRoot(uint256 questID, uint256 period, uint256 totalAmount, bytes32 merkleRoot) external isAlive onlyAllowed nonReentrant {
        period = (period / WEEK) * WEEK;
        _addMerkleRoot(questID, period, totalAmount, merkleRoot);
    }

    /**
    * @notice Sets a list of QuestPeriods as disitrbuted, and adds the MerkleRoot to the Distributor contract for each
    * @dev Loop and internal call to _addMerkleRoot()
    * @param questIDs List of Quest IDs
    * @param period Timestamp of the period
    * @param totalAmounts List of sums of all rewards for the Merkle Tree
    * @param merkleRoots List of MerkleRoots to add
    */
    function addMultipleMerkleRoot(
        uint256[] calldata questIDs,
        uint256 period,
        uint256[] calldata totalAmounts,
        bytes32[] calldata merkleRoots
    ) external isAlive onlyAllowed nonReentrant {
        period = (period / WEEK) * WEEK;
        uint256 length = questIDs.length;

        if(length != merkleRoots.length) revert Errors.InequalArraySizes();
        if(length != totalAmounts.length) revert Errors.InequalArraySizes();

        for(uint256 i = 0; i < length;){
            _addMerkleRoot(questIDs[i], period, totalAmounts[i], merkleRoots[i]);

            unchecked{ ++i; }
        }
    }
   
    /**
    * @notice Whitelists a reward token
    * @dev Whitelists a reward token
    * @param newToken Address of the reward token
    */
    function whitelistToken(address newToken, uint256 minRewardPerVote) public onlyAllowed {
        if(newToken == address(0)) revert Errors.ZeroAddress();
        if(minRewardPerVote == 0) revert Errors.InvalidParameter();

        whitelistedTokens[newToken] = true;

        minRewardPerVotePerToken[newToken] = minRewardPerVote;

        emit WhitelistToken(newToken, minRewardPerVote);
    }
   
    /**
    * @notice Whitelists a list of reward tokens
    * @dev Whitelists a list of reward tokens
    * @param newTokens List of reward tokens addresses
    */
    function whitelistMultipleTokens(address[] calldata newTokens, uint256[] calldata minRewardPerVotes) external onlyAllowed {
        uint256 length = newTokens.length;

        if(length == 0) revert Errors.EmptyArray();
        if(length != minRewardPerVotes.length) revert Errors.InequalArraySizes();

        for(uint256 i = 0; i < length;){
            whitelistToken(newTokens[i], minRewardPerVotes[i]);

            unchecked{ ++i; }
        }
    }

    function updateRewardToken(address newToken, uint256 newMinRewardPerVote) external onlyAllowed {
        if(!whitelistedTokens[newToken]) revert Errors.TokenNotWhitelisted();
        if(newMinRewardPerVote == 0) revert Errors.InvalidParameter();

        minRewardPerVotePerToken[newToken] = newMinRewardPerVote;

        emit UpdateRewardToken(newToken, newMinRewardPerVote);
    }

    // Admin functions
   
    /**
    * @notice Sets an initial Distributor address
    * @dev Sets an initial Distributor address
    * @param newDistributor Address of the Distributor
    */
    function initiateDistributor(address newDistributor) external onlyOwner {
        if(distributor != address(0)) revert Errors.AlreadyInitialized();
        distributor = newDistributor;

        emit InitDistributor(newDistributor);
    }


    /*
        This method is needed for managers to force this contract, in case the reduced bias
        calculated for the Gauge is incorrect for the period to close.
        The following scenario can create a difference between the expected Gauge Bias & the one calculated:
        Avoting address, listed in the Blacklist for the given Quest, is already voting for the target Gauge
        Between the moment where the period is ended (Thursday 00:00 GMT) and the moment the closeQuestPeriod()
        method is called, and does the calculation for the Gauge Bias (and removes the blacklisted voter bias),
        the blacklisted voter changes its vote on the Gauge (by increasing it, or reducing it, or even removing it),
        allowing it to change its last VotedSlope for that Gauge, and causing our system not to account correctly
        for the Bias used for the voting period we are closing
        This method will then allow to send the correct reduced Bias for the Gauge for the given period,
        and calculate the rewards for that period correctly (and do the required reward token transfers)
        !!! => this method needs the 
    */
    function fixQuestPeriodBias(uint256 period, uint256 questID, uint256 correctReducedBias) external isAlive onlyOwner nonReentrant {
        period = (period / WEEK) * WEEK;
        if(questID >= nextID) revert Errors.InvalidQuestID();
        if(distributor == address(0)) revert Errors.NoDistributorSet();
        if(period == 0) revert Errors.InvalidPeriod();
        if(period > getCurrentPeriod()) revert Errors.InvalidPeriod();

        QuestPeriod memory _questPeriod = periodsByQuest[questID][period];

        // This also allows to check if the given period is correct => If not, the currentState is never set to CLOSED for the QuestPeriod
        if(_questPeriod.currentState != PeriodState.CLOSED) revert Errors.PeriodNotClosed();

        uint256 previousRewardAmountDistributed = _questPeriod.rewardAmountDistributed;

        address questDistributor = questDistributors[questID];

        if(correctReducedBias == 0) { 
            // Set rewardAmountDistributed back to 0, get all rewards token back to the Board
            // and put the period rewards as withdrawable for the Quest creator
            _questPeriod.rewardAmountDistributed = 0;
            _questPeriod.withdrawableAmount = _questPeriod.rewardAmountPerPeriod;

            if(!MultiMerkleDistributor(questDistributor).fixQuestPeriod(questID, period, 0)) revert Errors.DisitributorFail();
        }
        else{
            uint256 newToDistributeAmount = correctReducedBias >= _questPeriod.objectiveVotes ? _questPeriod.rewardAmountPerPeriod : (correctReducedBias * _questPeriod.rewardPerVote) / UNIT;

            _questPeriod.rewardAmountDistributed = newToDistributeAmount;
            // And the rest is set as withdrawable amount, that the Quest creator can retrieve
            _questPeriod.withdrawableAmount = _questPeriod.rewardAmountPerPeriod - newToDistributeAmount;

            if(newToDistributeAmount > previousRewardAmountDistributed){
                uint256 missingAmount = newToDistributeAmount - previousRewardAmountDistributed;
                IERC20(quests[questID].rewardToken).safeTransfer(questDistributor, missingAmount);
            }
            // Otherwise, the Distributor will return the extra amount token to this contract

            if(!MultiMerkleDistributor(questDistributor).fixQuestPeriod(questID, period, newToDistributeAmount)) revert Errors.DisitributorFail();
        }

        periodsByQuest[questID][period] =  _questPeriod;

        emit PeriodBiasFixed(period, questID, correctReducedBias);
    }
   
    /**
    * @notice Approves a new address as manager 
    * @dev Approves a new address as manager
    * @param newManager Address to add
    */
    function approveManager(address newManager) external onlyOwner {
        if(newManager == address(0)) revert Errors.ZeroAddress();
        approvedManagers[newManager] = true;

        emit ApprovedManager(newManager);
    }
   
    /**
    * @notice Removes an address from the managers
    * @dev Removes an address from the managers
    * @param manager Address to remove
    */
    function removeManager(address manager) external onlyOwner {
        if(manager == address(0)) revert Errors.ZeroAddress();
        approvedManagers[manager] = false;

        emit RemovedManager(manager);
    }
   
    /**
    * @notice Updates the Chest address
    * @dev Updates the Chest address
    * @param chest Address of the new Chest
    */
    function updateChest(address chest) external onlyOwner {
        if(chest == address(0)) revert Errors.ZeroAddress();
        address oldChest = questChest;
        questChest = chest;

        emit ChestUpdated(oldChest, chest);
    }
   
    /**
    * @notice Updates the Distributor address
    * @dev Updates the Distributor address
    * @param newDistributor Address of the new Distributor
    */
    function updateDistributor(address newDistributor) external onlyOwner {
        if(newDistributor == address(0)) revert Errors.ZeroAddress();
        address oldDistributor = distributor;
        distributor = newDistributor;

        emit DistributorUpdated(oldDistributor, distributor);
    }
   
    /**
    * @notice Updates the Platfrom fees BPS ratio
    * @dev Updates the Platfrom fees BPS ratio
    * @param newFee New fee ratio
    */
    function updatePlatformFee(uint256 newFee) external onlyOwner {
        if(newFee > 500) revert Errors.InvalidParameter();
        uint256 oldfee = platformFee;
        platformFee = newFee;

        emit PlatformFeeUpdated(oldfee, newFee);
    }
   
    /**
    * @notice Updates the min objective value
    * @dev Updates the min objective value
    * @param newMinObjective New min objective
    */
    function updateMinObjective(uint256 newMinObjective) external onlyOwner {
        if(newMinObjective == 0) revert Errors.InvalidParameter();
        uint256 oldMinObjective = minObjective;
        minObjective = newMinObjective;

        emit MinObjectiveUpdated(oldMinObjective, newMinObjective);
    }
   
    /**
    * @notice Recovers ERC2O tokens sent by mistake to the contract
    * @dev Recovers ERC2O tokens sent by mistake to the contract
    * @param token Address tof the EC2O token
    * @return bool: success
    */
    function recoverERC20(address token) external onlyOwner returns(bool) {
        if(whitelistedTokens[token]) revert Errors.CannotRecoverToken();

        uint256 amount = IERC20(token).balanceOf(address(this));
        if(amount == 0) revert Errors.NullAmount();
        IERC20(token).safeTransfer(owner(), amount);

        return true;
    }
   
    /**
    * @notice Kills the contract
    * @dev Kills the contract
    */
    function killBoard() external onlyOwner {
        if(isKilled) revert Errors.AlreadyKilled();
        isKilled = true;
        kill_ts = block.timestamp;

        emit Killed(kill_ts);
    }
   
    /**
    * @notice Unkills the contract
    * @dev Unkills the contract
    */
    function unkillBoard() external onlyOwner {
        if(!isKilled) revert Errors.NotKilled();
        if(block.timestamp >= kill_ts + KILL_DELAY) revert Errors.KillDelayExpired();
        isKilled = false;

        emit Unkilled(block.timestamp);
    }



    // Utils 

    function safe48(uint n) internal pure returns (uint48) {
        if(n > type(uint48).max) revert Errors.NumberExceed48Bits();
        return uint48(n);
    }

}
// File: contracts/oz/interfaces/IERC20.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (token/ERC20/IERC20.sol)

pragma solidity ^0.8.0;

/**
 * @dev Interface of the ERC20 standard as defined in the EIP.
 */
interface IERC20 {
    /**
     * @dev Returns the amount of tokens in existence.
     */
    function totalSupply() external view returns (uint256);

    /**
     * @dev Returns the amount of tokens owned by `account`.
     */
    function balanceOf(address account) external view returns (uint256);

    /**
     * @dev Moves `amount` tokens from the caller's account to `recipient`.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transfer(address recipient, uint256 amount) external returns (bool);

    /**
     * @dev Returns the remaining number of tokens that `spender` will be
     * allowed to spend on behalf of `owner` through {transferFrom}. This is
     * zero by default.
     *
     * This value changes when {approve} or {transferFrom} are called.
     */
    function allowance(address owner, address spender) external view returns (uint256);

    /**
     * @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * IMPORTANT: Beware that changing an allowance with this method brings the risk
     * that someone may use both the old and the new allowance by unfortunate
     * transaction ordering. One possible solution to mitigate this race
     * condition is to first reduce the spender's allowance to 0 and set the
     * desired value afterwards:
     * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
     *
     * Emits an {Approval} event.
     */
    function approve(address spender, uint256 amount) external returns (bool);

    /**
     * @dev Moves `amount` tokens from `sender` to `recipient` using the
     * allowance mechanism. `amount` is then deducted from the caller's
     * allowance.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transferFrom(
        address sender,
        address recipient,
        uint256 amount
    ) external returns (bool);

    /**
     * @dev Emitted when `value` tokens are moved from one account (`from`) to
     * another (`to`).
     *
     * Note that `value` may be zero.
     */
    event Transfer(address indexed from, address indexed to, uint256 value);

    /**
     * @dev Emitted when the allowance of a `spender` for an `owner` is set by
     * a call to {approve}. `value` is the new allowance.
     */
    event Approval(address indexed owner, address indexed spender, uint256 value);
}
// File: contracts/oz/libraries/SafeERC20.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (token/ERC20/utils/SafeERC20.sol)

pragma solidity ^0.8.0;

import "../interfaces/IERC20.sol";
import "../utils/Address.sol";

/**
 * @title SafeERC20
 * @dev Wrappers around ERC20 operations that throw on failure (when the token
 * contract returns false). Tokens that return no value (and instead revert or
 * throw on failure) are also supported, non-reverting calls are assumed to be
 * successful.
 * To use this library you can add a `using SafeERC20 for IERC20;` statement to your contract,
 * which allows you to call the safe operations as `token.safeTransfer(...)`, etc.
 */
library SafeERC20 {
    using Address for address;

    function safeTransfer(
        IERC20 token,
        address to,
        uint256 value
    ) internal {
        _callOptionalReturn(token, abi.encodeWithSelector(token.transfer.selector, to, value));
    }

    function safeTransferFrom(
        IERC20 token,
        address from,
        address to,
        uint256 value
    ) internal {
        _callOptionalReturn(token, abi.encodeWithSelector(token.transferFrom.selector, from, to, value));
    }

    /**
     * @dev Deprecated. This function has issues similar to the ones found in
     * {IERC20-approve}, and its usage is discouraged.
     *
     * Whenever possible, use {safeIncreaseAllowance} and
     * {safeDecreaseAllowance} instead.
     */
    function safeApprove(
        IERC20 token,
        address spender,
        uint256 value
    ) internal {
        // safeApprove should only be called when setting an initial allowance,
        // or when resetting it to zero. To increase and decrease it, use
        // 'safeIncreaseAllowance' and 'safeDecreaseAllowance'
        require(
            (value == 0) || (token.allowance(address(this), spender) == 0),
            "SafeERC20: approve from non-zero to non-zero allowance"
        );
        _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, value));
    }

    function safeIncreaseAllowance(
        IERC20 token,
        address spender,
        uint256 value
    ) internal {
        uint256 newAllowance = token.allowance(address(this), spender) + value;
        _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
    }

    function safeDecreaseAllowance(
        IERC20 token,
        address spender,
        uint256 value
    ) internal {
        unchecked {
            uint256 oldAllowance = token.allowance(address(this), spender);
            require(oldAllowance >= value, "SafeERC20: decreased allowance below zero");
            uint256 newAllowance = oldAllowance - value;
            _callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
        }
    }

    /**
     * @dev Imitates a Solidity high-level call (i.e. a regular function call to a contract), relaxing the requirement
     * on the return value: the return value is optional (but if data is returned, it must not be false).
     * @param token The token targeted by the call.
     * @param data The call data (encoded using abi.encode or one of its variants).
     */
    function _callOptionalReturn(IERC20 token, bytes memory data) private {
        // We need to perform a low level call here, to bypass Solidity's return data size checking mechanism, since
        // we're implementing it ourselves. We use {Address.functionCall} to perform this call, which verifies that
        // the target address contains contract code and also asserts for success in the low-level call.

        bytes memory returndata = address(token).functionCall(data, "SafeERC20: low-level call failed");
        if (returndata.length > 0) {
            // Return data is optional
            require(abi.decode(returndata, (bool)), "SafeERC20: ERC20 operation did not succeed");
        }
    }
}
// File: contracts/utils/Owner.sol



// SPDX-License-Identifier: MIT
pragma solidity ^0.8.10;

import "../oz/utils/Ownable.sol";

/** @title Extend OZ Ownable contract  */
/// @author Paladin

contract Owner is Ownable {

    address public pendingOwner;

    event NewPendingOwner(address indexed previousPendingOwner, address indexed newPendingOwner);

    error CannotBeOwner();
    error CallerNotPendingOwner();
    error ZeroAddress();

    function transferOwnership(address newOwner) public override virtual onlyOwner {
        if(newOwner == address(0)) revert ZeroAddress();
        if(newOwner == owner()) revert CannotBeOwner();
        address oldPendingOwner = pendingOwner;

        pendingOwner = newOwner;

        emit NewPendingOwner(oldPendingOwner, newOwner);
    }

    function acceptOwnership() public virtual {
        if(msg.sender != pendingOwner) revert CallerNotPendingOwner();
        address newOwner = pendingOwner;
        _transferOwnership(pendingOwner);
        pendingOwner = address(0);

        emit NewPendingOwner(newOwner, address(0));
    }

}
// File: contracts/oz/utils/ReentrancyGuard.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (security/ReentrancyGuard.sol)

pragma solidity ^0.8.0;

/**
 * @dev Contract module that helps prevent reentrant calls to a function.
 *
 * Inheriting from `ReentrancyGuard` will make the {nonReentrant} modifier
 * available, which can be applied to functions to make sure there are no nested
 * (reentrant) calls to them.
 *
 * Note that because there is a single `nonReentrant` guard, functions marked as
 * `nonReentrant` may not call one another. This can be worked around by making
 * those functions `private`, and then adding `external` `nonReentrant` entry
 * points to them.
 *
 * TIP: If you would like to learn more about reentrancy and alternative ways
 * to protect against it, check out our blog post
 * https://blog.openzeppelin.com/reentrancy-after-istanbul/[Reentrancy After Istanbul].
 */
abstract contract ReentrancyGuard {
    // Booleans are more expensive than uint256 or any type that takes up a full
    // word because each write operation emits an extra SLOAD to first read the
    // slot's contents, replace the bits taken up by the boolean, and then write
    // back. This is the compiler's defense against contract upgrades and
    // pointer aliasing, and it cannot be disabled.

    // The values being non-zero value makes deployment a bit more expensive,
    // but in exchange the refund on every call to nonReentrant will be lower in
    // amount. Since refunds are capped to a percentage of the total
    // transaction's gas, it is best to keep them low in cases like this one, to
    // increase the likelihood of the full refund coming into effect.
    uint256 private constant _NOT_ENTERED = 1;
    uint256 private constant _ENTERED = 2;

    uint256 private _status;

    constructor() {
        _status = _NOT_ENTERED;
    }

    /**
     * @dev Prevents a contract from calling itself, directly or indirectly.
     * Calling a `nonReentrant` function from another `nonReentrant`
     * function is not supported. It is possible to prevent this from happening
     * by making the `nonReentrant` function external, and making it call a
     * `private` function that does the actual work.
     */
    modifier nonReentrant() {
        // On the first call to nonReentrant, _notEntered will be true
        require(_status != _ENTERED, "ReentrancyGuard: reentrant call");

        // Any calls to nonReentrant after this point will fail
        _status = _ENTERED;

        _;

        // By storing the original value once again, a refund is triggered (see
        // https://eips.ethereum.org/EIPS/eip-2200)
        _status = _NOT_ENTERED;
    }
}
// File: contracts/MultiMerkleDistributor.sol



//██████╗  █████╗ ██╗      █████╗ ██████╗ ██╗███╗   ██╗
//██╔══██╗██╔══██╗██║     ██╔══██╗██╔══██╗██║████╗  ██║
//██████╔╝███████║██║     ███████║██║  ██║██║██╔██╗ ██║
//██╔═══╝ ██╔══██║██║     ██╔══██║██║  ██║██║██║╚██╗██║
//██║     ██║  ██║███████╗██║  ██║██████╔╝██║██║ ╚████║
//╚═╝     ╚═╝  ╚═╝╚══════╝╚═╝  ╚═╝╚═════╝ ╚═╝╚═╝  ╚═══╝
 

// SPDX-License-Identifier: MIT
pragma solidity 0.8.10;

import "./oz/interfaces/IERC20.sol";
import "./oz/libraries/SafeERC20.sol";
import "./oz/utils/MerkleProof.sol";
import "./utils/Owner.sol";
import "./oz/utils/ReentrancyGuard.sol";
import "./utils/Errors.sol";

/** @title Warden Quest Multi Merkle Distributor  */
/// @author Paladin
/*
    Contract holds ERC20 rewards from Quests
    Can handle multiple MerkleRoots
*/

contract MultiMerkleDistributor is Owner, ReentrancyGuard {
    using SafeERC20 for IERC20;

    /** @notice Seconds in a Week */
    uint256 private constant WEEK = 604800;

    /** @notice Mapping listing the reward token associated to each Quest ID */
    // QuestID => reward token
    mapping(uint256 => address) public questRewardToken;

    /** @notice Mapping of tokens this contract is or was distributing */
    // token address => boolean
    mapping(address => bool) public rewardTokens;

    //Periods: timestamp => start of a week, used as a voting period 
    //in the Curve GaugeController though the timestamp / WEEK *  WEEK logic.
    //Handled through the QuestManager contract.
    //Those can be fetched through this contract when they are closed, or through the QuestManager contract.

    /** @notice List of Closed QuestPeriods by Quest ID */
    // QuestID => array of periods
    mapping(uint256 => uint256[]) public questClosedPeriods;

    /** @notice Merkle Root for each period of a Quest (indexed by Quest ID) */
    // QuestID => period => merkleRoot
    mapping(uint256 => mapping(uint256 => bytes32)) public questMerkleRootPerPeriod;

    /** @notice Amount of rewards for each period of a Quest (indexed by Quest ID) */
    // QuestID => period => totalRewardsAmount
    mapping(uint256 => mapping(uint256 => uint256)) public questRewardsPerPeriod;

    /** @notice BitMap of claims for each period of a Quest */
    // QuestID => period => claimedBitMap
    // This is a packed array of booleans.
    mapping(uint256 => mapping(uint256 => mapping(uint256 => uint256))) private questPeriodClaimedBitMap;

    /** @notice Address of the QuestBoard contract */
    address public immutable questBoard;


    // Events

    /** @notice Event emitted when an user Claims */
    event Claimed(
        uint256 indexed questID,
        uint256 indexed period,
        uint256 index,
        uint256 amount,
        address rewardToken,
        address indexed account
    );
    /** @notice Event emitted when a New Quest is added */
    event NewQuest(uint256 indexed questID, address rewardToken);
    /** @notice Event emitted when a Period of a Quest is updated (when the Merkle Root is added) */
    event QuestPeriodUpdated(uint256 indexed questID, uint256 indexed period, bytes32 merkleRoot);


    // Modifier

    /** @notice Check the caller is either the admin or the QuestBoard contract */
    modifier onlyAllowed(){
        if(msg.sender != questBoard && msg.sender != owner()) revert Errors.CallerNotAllowed();
        _;
    }


    // Constructor

    constructor(address _questBoard){
        if(_questBoard == address(0)) revert Errors.ZeroAddress();

        questBoard = _questBoard;
    }

    // Functions
   
    /**
    * @notice Checks if the rewards were claimed for an user on a given period
    * @dev Checks if the rewards were claimed for an user (based on the index) on a given period
    * @param questID ID of the Quest
    * @param period Amount of underlying to borrow
    * @param index Index of the claim
    * @return bool : true if already claimed
    */
    function isClaimed(uint256 questID, uint256 period, uint256 index) public view returns (bool) {
        uint256 claimedWordIndex = index >> 8;
        uint256 claimedBitIndex = index & 0xff;
        uint256 claimedWord = questPeriodClaimedBitMap[questID][period][claimedWordIndex];
        uint256 mask = (1 << claimedBitIndex);
        return claimedWord & mask != 0;
    }
   
    /**
    * @dev Sets the rewards as claimed for the index on the given period
    * @param questID ID of the Quest
    * @param period Timestamp of the period
    * @param index Index of the claim
    */
    function _setClaimed(uint256 questID, uint256 period, uint256 index) private {
        uint256 claimedWordIndex = index >> 8;
        uint256 claimedBitIndex = index & 0xff;
        questPeriodClaimedBitMap[questID][period][claimedWordIndex] |= (1 << claimedBitIndex);
    }

    //Basic Claim   
    /**
    * @notice Claims the reward for an user for a given period of a Quest
    * @dev Claims the reward for an user for a given period of a Quest if the correct proof was given
    * @param questID ID of the Quest
    * @param period Timestamp of the period
    * @param index Index in the Merkle Tree
    * @param account Address of the user claiming the rewards
    * @param amount Amount of rewards to claim
    * @param merkleProof Proof to claim the rewards
    */
    function claim(uint256 questID, uint256 period, uint256 index, address account, uint256 amount, bytes32[] calldata merkleProof) public nonReentrant {
        if(account == address(0)) revert Errors.ZeroAddress();
        if(questMerkleRootPerPeriod[questID][period] == 0) revert Errors.MerkleRootNotUpdated();
        if(isClaimed(questID, period, index)) revert Errors.AlreadyClaimed();

        // Check that the given parameters match the given Proof
        bytes32 node = keccak256(abi.encodePacked(questID, period, index, account, amount));
        if(!MerkleProof.verify(merkleProof, questMerkleRootPerPeriod[questID][period], node)) revert Errors.InvalidProof();

        // Set the rewards as claimed for that period
        // And transfer the rewards to the user
        address rewardToken = questRewardToken[questID];
        _setClaimed(questID, period, index);
        questRewardsPerPeriod[questID][period] -= amount;
        IERC20(rewardToken).safeTransfer(account, amount);

        emit Claimed(questID, period, index, amount, rewardToken, account);
    }


    //Struct ClaimParams
    struct ClaimParams {
        uint256 questID;
        uint256 period;
        uint256 index;
        uint256 amount;
        bytes32[] merkleProof;
    }


    //Multi Claim   
    /**
    * @notice Claims multiple rewards for a given list
    * @dev Calls the claim() method for each entry in the claims array
    * @param account Address of the user claiming the rewards
    * @param claims List of ClaimParams struct data to claim
    */
    function multiClaim(address account, ClaimParams[] calldata claims) external {
        uint256 length = claims.length;
        
        if(length == 0) revert Errors.EmptyParameters();

        for(uint256 i; i < length;){
            claim(claims[i].questID, claims[i].period, claims[i].index, account, claims[i].amount, claims[i].merkleProof);

            unchecked{ ++i; }
        }
    }


    //FullQuest Claim (form of Multi Claim but for only one Quest => only one ERC20 transfer)
    //Only works for the given periods (in ClaimParams) for the Quest. Any omitted period will be skipped   
    /**
    * @notice Claims the reward for all the given periods of a Quest, and transfer all the rewards at once
    * @dev Sums up all the rewards for given periods of a Quest, and executes only one transfer
    * @param account Address of the user claiming the rewards
    * @param questID ID of the Quest
    * @param claims List of ClaimParams struct data to claim
    */
    function claimQuest(address account, uint256 questID, ClaimParams[] calldata claims) external nonReentrant {
        if(account == address(0)) revert Errors.ZeroAddress();
        uint256 length = claims.length;

        if(length == 0) revert Errors.EmptyParameters();

        // Total amount claimable, to transfer at once
        uint256 totalClaimAmount;
        address rewardToken = questRewardToken[questID];

        for(uint256 i; i < length;){
            if(claims[i].questID != questID) revert Errors.IncorrectQuestID();
            if(questMerkleRootPerPeriod[questID][claims[i].period] == 0) revert Errors.MerkleRootNotUpdated();
            if(isClaimed(questID, claims[i].period, claims[i].index)) revert Errors.AlreadyClaimed();

            // For each period given, if the proof matches the given parameters, 
            // set as claimed and add to the to total to transfer
            bytes32 node = keccak256(abi.encodePacked(questID, claims[i].period, claims[i].index, account, claims[i].amount));
            if(!MerkleProof.verify(claims[i].merkleProof, questMerkleRootPerPeriod[questID][claims[i].period], node)) revert Errors.InvalidProof();

            _setClaimed(questID, claims[i].period, claims[i].index);
            questRewardsPerPeriod[questID][claims[i].period] -= claims[i].amount;
            totalClaimAmount += claims[i].amount;

            emit Claimed(questID, claims[i].period, claims[i].index, claims[i].amount, rewardToken, account);

            unchecked{ ++i; }
        }

        // Transfer the total claimed amount
        IERC20(rewardToken).safeTransfer(account, totalClaimAmount);
    }

   
    /**
    * @notice Returns all current Closed periods for the given Quest ID
    * @dev Returns all current Closed periods for the given Quest ID
    * @param questID ID of the Quest
    * @return uint256[] : List of closed periods
    */
    function getClosedPeriodsByQuests(uint256 questID) external view returns (uint256[] memory) {
        return questClosedPeriods[questID];
    }



    // Manager functions
   
    /**
    * @notice Adds a new Quest to the listing
    * @dev Adds a new Quest ID and the associated reward token
    * @param questID ID of the Quest
    * @param token Address of the ERC20 reward token
    * @return bool : success
    */
    function addQuest(uint256 questID, address token) external returns(bool) {
        if(msg.sender != questBoard) revert Errors.CallerNotAllowed();
        if(questRewardToken[questID] != address(0)) revert Errors.QuestAlreadyListed();
        if(token == address(0)) revert Errors.TokenNotWhitelisted();

        // Add a new Quest using the QuestID, and list the reward token for that Quest
        questRewardToken[questID] = token;

        if(!rewardTokens[token]) rewardTokens[token] = true;

        emit NewQuest(questID, token);

        return true;
    }

    /**
    * @notice Adds a new period & the rewards of this period for a Quest
    * @dev Adds a new period & the rewards of this period for a Quest
    * @param questID ID of the Quest
    * @param period Timestamp of the period
    * @param totalRewardAmount Total amount of rewards to distribute for the period
    * @return bool : success
    */
    function addQuestPeriod(uint256 questID, uint256 period, uint256 totalRewardAmount) external returns(bool) {
        period = (period / WEEK) * WEEK;
        if(msg.sender != questBoard) revert Errors.CallerNotAllowed();
        if(questRewardToken[questID] == address(0)) revert Errors.QuestNotListed();
        if(questRewardsPerPeriod[questID][period] != 0) revert Errors.PeriodAlreadyUpdated();
        if(period == 0) revert Errors.IncorrectPeriod();
        if(totalRewardAmount == 0) revert Errors.NullAmount();

        questRewardsPerPeriod[questID][period] = totalRewardAmount;

        return true;
    }


    function fixQuestPeriod(uint256 questID, uint256 period, uint256 newTotalRewardAmount) external returns(bool) {
        if(msg.sender != questBoard) revert Errors.CallerNotAllowed();
        period = (period / WEEK) * WEEK;
        if(questRewardToken[questID] == address(0)) revert Errors.QuestNotListed();
        if(period == 0) revert Errors.IncorrectPeriod();
        if(questRewardsPerPeriod[questID][period] == 0) revert Errors.PeriodNotListed();

        uint256 previousTotalRewardAmount = questRewardsPerPeriod[questID][period];

        questRewardsPerPeriod[questID][period] = newTotalRewardAmount;

        if(previousTotalRewardAmount > newTotalRewardAmount){
            // Send back the extra amount of reward token that was incorrectly sent
            // In the case of missing reward token, the Board will send them to this contract

            uint256 extraAmount = previousTotalRewardAmount - newTotalRewardAmount;
            IERC20(questRewardToken[questID]).safeTransfer(questBoard, extraAmount);
        }

        return true;
    }
   
    /**
    * @notice Updates the period of a Quest by adding the Merkle Root
    * @dev Add the Merkle Root for the eriod of the given Quest
    * @param questID ID of the Quest
    * @param period timestamp of the period
    * @param totalAmount sum of all rewards for the Merkle Tree
    * @param merkleRoot MerkleRoot to add
    * @return bool: success
    */
    function updateQuestPeriod(uint256 questID, uint256 period, uint256 totalAmount, bytes32 merkleRoot) external onlyAllowed returns(bool) {
        period = (period / WEEK) * WEEK;
        if(questRewardToken[questID] == address(0)) revert Errors.QuestNotListed();
        if(period == 0) revert Errors.IncorrectPeriod();
        if(questRewardsPerPeriod[questID][period] == 0) revert Errors.PeriodNotListed();
        if(questMerkleRootPerPeriod[questID][period] != 0) revert Errors.PeriodAlreadyUpdated();
        if(merkleRoot == 0) revert Errors.EmptyMerkleRoot();

        // Add a new Closed Period for the Quest
        questClosedPeriods[questID].push(period);

        if(totalAmount != questRewardsPerPeriod[questID][period]) revert Errors.IncorrectRewardAmount();

        // Add the new MerkleRoot for that Closed Period
        questMerkleRootPerPeriod[questID][period] = merkleRoot;

        emit QuestPeriodUpdated(questID, period, merkleRoot);

        return true;
    }


    //  Admin functions
   
    /**
    * @notice Recovers ERC2O tokens sent by mistake to the contract
    * @dev Recovers ERC2O tokens sent by mistake to the contract
    * @param token Address tof the EC2O token
    * @return bool: success
    */
    function recoverERC20(address token) external onlyOwner nonReentrant returns(bool) {
        if(rewardTokens[token]) revert Errors.CannotRecoverToken();
        uint256 amount = IERC20(token).balanceOf(address(this));
        if(amount == 0) revert Errors.NullAmount();
        IERC20(token).safeTransfer(owner(), amount);

        return true;
    }

    // 
    /**
    * @notice Allows to update the MerkleRoot for a given period of a Quest if the current Root is incorrect
    * @dev Updates the MerkleRoot for the period of the Quest
    * @param questID ID of the Quest
    * @param period Timestamp of the period
    * @param merkleRoot New MerkleRoot to add
    * @return bool : success
    */
    function emergencyUpdateQuestPeriod(uint256 questID, uint256 period, uint256 addedRewardAmount, bytes32 merkleRoot) external onlyOwner returns(bool) {
        // In case the given MerkleRoot was incorrect:
        // Process:
        // 1 - block claims for the Quest period by using this method to set an incorrect MerkleRoot, where no proof matches the root
        // 2 - prepare a new Merkle Tree, taking in account user previous claims on that period, and missing/overpaid rewards
        //      a - for all new claims to be added, set them after the last index of the previous Merkle Tree
        //      b - for users that did not claim, keep the same index, and adjust the amount to claim if needed
        //      c - for indexes that were claimed, place an empty node in the Merkle Tree (with an amount at 0 & the address 0xdead as the account)
        // 3 - update the Quest period with the correct MerkleRoot
        // (no need to change the Bitmap, as the new MerkleTree will account for the indexes already claimed)

        period = (period / WEEK) * WEEK;
        if(questRewardToken[questID] == address(0)) revert Errors.QuestNotListed();
        if(period == 0) revert Errors.IncorrectPeriod();
        if(questMerkleRootPerPeriod[questID][period] == 0) revert Errors.PeriodNotClosed();
        if(merkleRoot == 0) revert Errors.EmptyMerkleRoot();

        questMerkleRootPerPeriod[questID][period] = merkleRoot;

        questRewardsPerPeriod[questID][period] += addedRewardAmount;

        emit QuestPeriodUpdated(questID, period, merkleRoot);

        return true;
    }

}
// File: contracts/interfaces/IGaugeController.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

/**
 * @dev Interface made for the Curve's GaugeController contract
 */
interface IGaugeController {

    struct VotedSlope {
        uint slope;
        uint power;
        uint end;
    }
    
    struct Point {
        uint bias;
        uint slope;
    }
    
    function vote_user_slopes(address, address) external view returns(VotedSlope memory);
    function last_user_vote(address, address) external view returns(uint);
    function points_weight(address, uint256) external view returns(Point memory);
    function checkpoint_gauge(address) external;
    function gauge_types(address _addr) external view returns(int128);
    
}
// File: contracts/utils/Errors.sol



pragma solidity 0.8.10;
//SPDX-License-Identifier: MIT

library Errors {

    // Common Errors
    error ZeroAddress();
    error NullAmount();
    error CallerNotAllowed();
    error IncorrectRewardToken();
    error SameAddress();
    error InequalArraySizes();
    error EmptyArray();
    error EmptyParameters();
    error AlreadyInitialized();
    error InvalidParameter();
    error CannotRecoverToken();
    error ForbiddenCall();

    error Killed();
    error AlreadyKilled();
    error NotKilled();
    error KillDelayExpired();
    error KillDelayNotExpired();


    // Merkle Errors
    error MerkleRootNotUpdated();
    error AlreadyClaimed();
    error InvalidProof();
    error EmptyMerkleRoot();
    error IncorrectRewardAmount();


    // Quest Errors
    error CallerNotQuestBoard();
    error IncorrectQuestID();
    error IncorrectPeriod();
    error TokenNotWhitelisted();
    error QuestAlreadyListed();
    error QuestNotListed();
    error PeriodAlreadyUpdated();
    error PeriodNotClosed();
    error PeriodStillActive();
    error PeriodNotListed();
    error EmptyQuest();
    error EmptyPeriod();
    error ExpiredQuest();

    error NoDistributorSet();
    error DisitributorFail();
    error InvalidGauge();
    error InvalidQuestID();
    error InvalidPeriod();
    error ObjectiveTooLow();
    error RewardPerVoteTooLow();
    error IncorrectDuration();
    error IncorrectAddDuration();
    error IncorrectTotalRewardAmount();
    error IncorrectAddedRewardAmount();
    error IncorrectFeeAmount();
    error CalletNotQuestCreator();
    error LowerRewardPerVote();
    error LowerObjective();
    error AlreadyBlacklisted();


    //Math
    error NumberExceed48Bits();

}
// File: contracts/oz/utils/Address.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/Address.sol)

pragma solidity ^0.8.1;

/**
 * @dev Collection of functions related to the address type
 */
library Address {
    /**
     * @dev Returns true if `account` is a contract.
     *
     * [IMPORTANT]
     * ====
     * It is unsafe to assume that an address for which this function returns
     * false is an externally-owned account (EOA) and not a contract.
     *
     * Among others, `isContract` will return false for the following
     * types of addresses:
     *
     *  - an externally-owned account
     *  - a contract in construction
     *  - an address where a contract will be created
     *  - an address where a contract lived, but was destroyed
     * ====
     *
     * [IMPORTANT]
     * ====
     * You shouldn't rely on `isContract` to protect against flash loan attacks!
     *
     * Preventing calls from contracts is highly discouraged. It breaks composability, breaks support for smart wallets
     * like Gnosis Safe, and does not provide security since it can be circumvented by calling from a contract
     * constructor.
     * ====
     */
    function isContract(address account) internal view returns (bool) {
        // This method relies on extcodesize/address.code.length, which returns 0
        // for contracts in construction, since the code is only stored at the end
        // of the constructor execution.

        return account.code.length > 0;
    }

    /**
     * @dev Replacement for Solidity's `transfer`: sends `amount` wei to
     * `recipient`, forwarding all available gas and reverting on errors.
     *
     * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
     * of certain opcodes, possibly making contracts go over the 2300 gas limit
     * imposed by `transfer`, making them unable to receive funds via
     * `transfer`. {sendValue} removes this limitation.
     *
     * https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].
     *
     * IMPORTANT: because control is transferred to `recipient`, care must be
     * taken to not create reentrancy vulnerabilities. Consider using
     * {ReentrancyGuard} or the
     * https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
     */
    function sendValue(address payable recipient, uint256 amount) internal {
        require(address(this).balance >= amount, "Address: insufficient balance");

        (bool success, ) = recipient.call{value: amount}("");
        require(success, "Address: unable to send value, recipient may have reverted");
    }

    /**
     * @dev Performs a Solidity function call using a low level `call`. A
     * plain `call` is an unsafe replacement for a function call: use this
     * function instead.
     *
     * If `target` reverts with a revert reason, it is bubbled up by this
     * function (like regular Solidity function calls).
     *
     * Returns the raw returned data. To convert to the expected return value,
     * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
     *
     * Requirements:
     *
     * - `target` must be a contract.
     * - calling `target` with `data` must not revert.
     *
     * _Available since v3.1._
     */
    function functionCall(address target, bytes memory data) internal returns (bytes memory) {
        return functionCall(target, data, "Address: low-level call failed");
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with
     * `errorMessage` as a fallback revert reason when `target` reverts.
     *
     * _Available since v3.1._
     */
    function functionCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal returns (bytes memory) {
        return functionCallWithValue(target, data, 0, errorMessage);
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but also transferring `value` wei to `target`.
     *
     * Requirements:
     *
     * - the calling contract must have an ETH balance of at least `value`.
     * - the called Solidity function must be `payable`.
     *
     * _Available since v3.1._
     */
    function functionCallWithValue(
        address target,
        bytes memory data,
        uint256 value
    ) internal returns (bytes memory) {
        return functionCallWithValue(target, data, value, "Address: low-level call with value failed");
    }

    /**
     * @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but
     * with `errorMessage` as a fallback revert reason when `target` reverts.
     *
     * _Available since v3.1._
     */
    function functionCallWithValue(
        address target,
        bytes memory data,
        uint256 value,
        string memory errorMessage
    ) internal returns (bytes memory) {
        require(address(this).balance >= value, "Address: insufficient balance for call");
        require(isContract(target), "Address: call to non-contract");

        (bool success, bytes memory returndata) = target.call{value: value}(data);
        return verifyCallResult(success, returndata, errorMessage);
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but performing a static call.
     *
     * _Available since v3.3._
     */
    function functionStaticCall(address target, bytes memory data) internal view returns (bytes memory) {
        return functionStaticCall(target, data, "Address: low-level static call failed");
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
     * but performing a static call.
     *
     * _Available since v3.3._
     */
    function functionStaticCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal view returns (bytes memory) {
        require(isContract(target), "Address: static call to non-contract");

        (bool success, bytes memory returndata) = target.staticcall(data);
        return verifyCallResult(success, returndata, errorMessage);
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but performing a delegate call.
     *
     * _Available since v3.4._
     */
    function functionDelegateCall(address target, bytes memory data) internal returns (bytes memory) {
        return functionDelegateCall(target, data, "Address: low-level delegate call failed");
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
     * but performing a delegate call.
     *
     * _Available since v3.4._
     */
    function functionDelegateCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal returns (bytes memory) {
        require(isContract(target), "Address: delegate call to non-contract");

        (bool success, bytes memory returndata) = target.delegatecall(data);
        return verifyCallResult(success, returndata, errorMessage);
    }

    /**
     * @dev Tool to verifies that a low level call was successful, and revert if it wasn't, either by bubbling the
     * revert reason using the provided one.
     *
     * _Available since v4.3._
     */
    function verifyCallResult(
        bool success,
        bytes memory returndata,
        string memory errorMessage
    ) internal pure returns (bytes memory) {
        if (success) {
            return returndata;
        } else {
            // Look for revert reason and bubble it up if present
            if (returndata.length > 0) {
                // The easiest way to bubble the revert reason is using memory via assembly

                assembly {
                    let returndata_size := mload(returndata)
                    revert(add(32, returndata), returndata_size)
                }
            } else {
                revert(errorMessage);
            }
        }
    }
}
// File: contracts/oz/utils/Ownable.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (access/Ownable.sol)

pragma solidity ^0.8.0;

import "./Context.sol";

/**
 * @dev Contract module which provides a basic access control mechanism, where
 * there is an account (an owner) that can be granted exclusive access to
 * specific functions.
 *
 * By default, the owner account will be the one that deploys the contract. This
 * can later be changed with {transferOwnership}.
 *
 * This module is used through inheritance. It will make available the modifier
 * `onlyOwner`, which can be applied to your functions to restrict their use to
 * the owner.
 */
abstract contract Ownable is Context {
    address private _owner;

    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);

    /**
     * @dev Initializes the contract setting the deployer as the initial owner.
     */
    constructor() {
        _transferOwnership(_msgSender());
    }

    /**
     * @dev Returns the address of the current owner.
     */
    function owner() public view virtual returns (address) {
        return _owner;
    }

    /**
     * @dev Throws if called by any account other than the owner.
     */
    modifier onlyOwner() {
        require(owner() == _msgSender(), "Ownable: caller is not the owner");
        _;
    }

    /**
     * @dev Leaves the contract without owner. It will not be possible to call
     * `onlyOwner` functions anymore. Can only be called by the current owner.
     *
     * NOTE: Renouncing ownership will leave the contract without an owner,
     * thereby removing any functionality that is only available to the owner.
     */
    function renounceOwnership() public virtual onlyOwner {
        _transferOwnership(address(0));
    }

    /**
     * @dev Transfers ownership of the contract to a new account (`newOwner`).
     * Can only be called by the current owner.
     */
    function transferOwnership(address newOwner) public virtual onlyOwner {
        require(newOwner != address(0), "Ownable: new owner is the zero address");
        _transferOwnership(newOwner);
    }

    /**
     * @dev Transfers ownership of the contract to a new account (`newOwner`).
     * Internal function without access restriction.
     */
    function _transferOwnership(address newOwner) internal virtual {
        address oldOwner = _owner;
        _owner = newOwner;
        emit OwnershipTransferred(oldOwner, newOwner);
    }
}
// File: contracts/oz/utils/Context.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/Context.sol)

pragma solidity ^0.8.0;

/**
 * @dev Provides information about the current execution context, including the
 * sender of the transaction and its data. While these are generally available
 * via msg.sender and msg.data, they should not be accessed in such a direct
 * manner, since when dealing with meta-transactions the account sending and
 * paying for execution may not be the actual sender (as far as an application
 * is concerned).
 *
 * This contract is only required for intermediate, library-like contracts.
 */
abstract contract Context {
    function _msgSender() internal view virtual returns (address) {
        return msg.sender;
    }

    function _msgData() internal view virtual returns (bytes calldata) {
        return msg.data;
    }
}
// File: contracts/oz/utils/MerkleProof.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/cryptography/MerkleProof.sol)

pragma solidity ^0.8.0;

/**
 * @dev These functions deal with verification of Merkle Trees proofs.
 *
 * The proofs can be generated using the JavaScript library
 * https://github.com/miguelmota/merkletreejs[merkletreejs].
 * Note: the hashing algorithm should be keccak256 and pair sorting should be enabled.
 *
 * See `test/utils/cryptography/MerkleProof.test.js` for some examples.
 */
library MerkleProof {
    /**
     * @dev Returns true if a `leaf` can be proved to be a part of a Merkle tree
     * defined by `root`. For this, a `proof` must be provided, containing
     * sibling hashes on the branch from the leaf to the root of the tree. Each
     * pair of leaves and each pair of pre-images are assumed to be sorted.
     */
    function verify(
        bytes32[] memory proof,
        bytes32 root,
        bytes32 leaf
    ) internal pure returns (bool) {
        return processProof(proof, leaf) == root;
    }

    /**
     * @dev Returns the rebuilt hash obtained by traversing a Merklee tree up
     * from `leaf` using `proof`. A `proof` is valid if and only if the rebuilt
     * hash matches the root of the tree. When processing the proof, the pairs
     * of leafs & pre-images are assumed to be sorted.
     *
     * _Available since v4.4._
     */
    function processProof(bytes32[] memory proof, bytes32 leaf) internal pure returns (bytes32) {
        bytes32 computedHash = leaf;
        for (uint256 i = 0; i < proof.length; i++) {
            bytes32 proofElement = proof[i];
            if (computedHash <= proofElement) {
                // Hash(current computed hash + current element of the proof)
                computedHash = _efficientHash(computedHash, proofElement);
            } else {
                // Hash(current element of the proof + current computed hash)
                computedHash = _efficientHash(proofElement, computedHash);
            }
        }
        return computedHash;
    }

    function _efficientHash(bytes32 a, bytes32 b) private pure returns (bytes32 value) {
        assembly {
            mstore(0x00, a)
            mstore(0x20, b)
            value := keccak256(0x00, 0x40)
        }
    }
}