// File: @openzeppelin/contracts/token/ERC20/extensions/IERC20Metadata.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (token/ERC20/extensions/IERC20Metadata.sol)

pragma solidity ^0.8.0;

import "../IERC20.sol";

/**
 * @dev Interface for the optional metadata functions from the ERC20 standard.
 *
 * _Available since v4.1._
 */
interface IERC20Metadata is IERC20 {
    /**
     * @dev Returns the name of the token.
     */
    function name() external view returns (string memory);

    /**
     * @dev Returns the symbol of the token.
     */
    function symbol() external view returns (string memory);

    /**
     * @dev Returns the decimals places of the token.
     */
    function decimals() external view returns (uint8);
}

// File: @openzeppelin/contracts/token/ERC20/IERC20.sol



// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (token/ERC20/IERC20.sol)

pragma solidity ^0.8.0;

/**
 * @dev Interface of the ERC20 standard as defined in the EIP.
 */
interface IERC20 {
    /**
     * @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);

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

// File: contracts/Dependencies/CheckContract.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.17;


contract CheckContract {
    /**
     * Check that the account is an already deployed non-destroyed contract.
     * See: https://github.com/OpenZeppelin/openzeppelin-contracts/blob/master/contracts/utils/Address.sol#L12
     */
    function checkContract(address _account) internal view {
        require(_account != address(0), "Account cannot be zero address");

        uint256 size;
        // solhint-disable-next-line no-inline-assembly
        assembly { size := extcodesize(_account) }
        require(size > 0, "Account code size cannot be zero");
    }
}

// File: contracts/Dependencies/IERC2612.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.17;

/**
 * @dev Interface of the ERC2612 standard as defined in the EIP.
 *
 * Adds the {permit} method, which can be used to change one's
 * {IERC20-allowance} without having to send a transaction, by signing a
 * message. This allows users to spend tokens without having to hold Ether.
 *
 * See https://eips.ethereum.org/EIPS/eip-2612.
 * 
 * Code adapted from https://github.com/OpenZeppelin/openzeppelin-contracts/pull/2237/
 */
interface IERC2612 {
    /**
     * @dev Sets `amount` as the allowance of `spender` over `owner`'s tokens,
     * given `owner`'s signed approval.
     *
     * IMPORTANT: The same issues {IERC20-approve} has related to transaction
     * ordering also apply here.
     *
     * Emits an {Approval} event.
     *
     * Requirements:
     *
     * - `owner` cannot be the zero address.
     * - `spender` cannot be the zero address.
     * - `deadline` must be a timestamp in the future.
     * - `v`, `r` and `s` must be a valid `secp256k1` signature from `owner`
     * over the EIP712-formatted function arguments.
     * - the signature must use ``owner``'s current nonce (see {nonces}).
     *
     * For more information on the signature format, see the
     * https://eips.ethereum.org/EIPS/eip-2612#specification[relevant EIP
     * section].
     */
    function permit(address owner, address spender, uint256 amount, 
                    uint256 deadline, uint8 v, bytes32 r, bytes32 s) external;
    
    /**
     * @dev Returns the current ERC2612 nonce for `owner`. This value must be
     * included whenever a signature is generated for {permit}.
     *
     * Every successful call to {permit} increases `owner`'s nonce by one. This
     * prevents a signature from being used multiple times.
     *
     * `owner` can limit the time a Permit is valid for by setting `deadline` to 
     * a value in the near future. The deadline argument can be set to uint(-1) to 
     * create Permits that effectively never expire.
     */
    function nonces(address owner) external view returns (uint256);
    
    function version() external view returns (string memory);
    function permitTypeHash() external view returns (bytes32);
    function domainSeparator() external view returns (bytes32);
}

// File: contracts/Dependencies/Ownable.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.17;

/**
 * Based on OpenZeppelin's Ownable contract:
 * https://github.com/OpenZeppelin/openzeppelin-contracts/blob/master/contracts/access/Ownable.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.
 *
 * 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.
 */
contract Ownable {
    address private _owner;

    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);

    /**
     * @dev Initializes the contract setting the deployer as the initial owner.
     */
    constructor () {
        _owner = msg.sender;
        emit OwnershipTransferred(address(0), msg.sender);
    }

    /**
     * @dev Returns the address of the current owner.
     */
    function owner() public view returns (address) {
        return _owner;
    }

    /**
     * @dev Throws if called by any account other than the owner.
     */
    modifier onlyOwner() {
        require(isOwner(), "Ownable: caller is not the owner");
        _;
    }

    /**
     * @dev Returns true if the caller is the current owner.
     */
    function isOwner() public view returns (bool) {
        return msg.sender == _owner;
    }

    /**
     * @dev Leaves the contract without owner. It will not be possible to call
     * `onlyOwner` functions anymore.
     *
     * NOTE: Renouncing ownership will leave the contract without an owner,
     * thereby removing any functionality that is only available to the owner.
     *
     * NOTE: This function is not safe, as it doesn’t check owner is calling it.
     * Make sure you check it before calling it.
     */
    function _renounceOwnership() internal {
        emit OwnershipTransferred(_owner, address(0));
        _owner = 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/Interfaces/IBorrowerOperations.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.17;

// Common interface for the Trove Manager.
interface IBorrowerOperations {

    // --- Events ---

    event TroveManagerAddressChanged(address _newTroveManagerAddress);
    event ActivePoolAddressChanged(address _activePoolAddress);
    event DefaultPoolAddressChanged(address _defaultPoolAddress);
    event StabilityPoolAddressChanged(address _stabilityPoolAddress);
    event GasPoolAddressChanged(address _gasPoolAddress);
    event CollSurplusPoolAddressChanged(address _collSurplusPoolAddress);
    event PriceFeedAddressChanged(address  _newPriceFeedAddress);
    event SortedTrovesAddressChanged(address _sortedTrovesAddress);
    event THUSDTokenAddressChanged(address _thusdTokenAddress);
    event PCVAddressChanged(address _pcvAddress);
    event CollateralAddressChanged(address _newCollateralAddress);

    event TroveCreated(address indexed _borrower, uint256 arrayIndex);
    event TroveUpdated(address indexed _borrower, uint256 _debt, uint256 _coll, uint256 stake, uint8 operation);
    event THUSDBorrowingFeePaid(address indexed _borrower, uint256 _THUSDFee);

    // --- Functions ---

    function setAddresses(
        address _troveManagerAddress,
        address _activePoolAddress,
        address _defaultPoolAddress,
        address _stabilityPoolAddress,
        address _gasPoolAddress,
        address _collSurplusPoolAddress,
        address _priceFeedAddress,
        address _sortedTrovesAddress,
        address _thusdTokenAddress,
        address _pcvAddress,
        address _collateralAddress

    ) external;

    function openTrove(uint256 _maxFee, uint256 _THUSDAmount, uint256 _assetAmount, address _upperHint, address _lowerHint) external payable;

    function addColl(uint256 _assetAmount, address _upperHint, address _lowerHint) external payable;

    function moveCollateralGainToTrove(address _user, uint256 _assetAmount, address _upperHint, address _lowerHint) external payable;

    function withdrawColl(uint256 _amount, address _upperHint, address _lowerHint) external;

    function withdrawTHUSD(uint256 _maxFee, uint256 _amount, address _upperHint, address _lowerHint) external;

    function repayTHUSD(uint256 _amount, address _upperHint, address _lowerHint) external;

    function closeTrove() external;

    function adjustTrove(uint256 _maxFee, uint256 _collWithdrawal, uint256 _debtChange, bool isDebtIncrease, uint256 _assetAmount, address _upperHint, address _lowerHint) external payable;

    function claimCollateral() external;

    function getCompositeDebt(uint256 _debt) external pure returns (uint);

    function collateralAddress() external view returns(address);
}

// File: contracts/Interfaces/ILiquityBase.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.17;

import "./IPriceFeed.sol";


interface ILiquityBase {
    function priceFeed() external view returns (IPriceFeed);
}

// File: contracts/Interfaces/IPCV.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.17;

import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
import "./ITHUSDToken.sol";

interface IPCV {

    // --- Events --
    event THUSDTokenAddressSet(address _thusdTokenAddress);
    event BorrowerOperationsAddressSet(address _borrowerOperationsAddress);
    event CollateralAddressSet(address _collateralAddress);
    event BAMMAddressSet(address _bammAddress);
    event RolesSet(address _council, address _treasury);

    event BAMMDeposit(uint256 _thusdAmount);
    event BAMMWithdraw(uint256 _numShares);
    event THUSDWithdraw(address _recipient, uint256 _thusdAmount);
    event CollateralWithdraw(address _recipient, uint256 _collateralAmount);

    event PCVDebtPaid(uint256 _paidDebt);
    
    event RecipientAdded(address _recipient);
    event RecipientRemoved(address _recipient);

    // --- Functions ---

    function debtToPay() external returns(uint256);
    function payDebt(uint256 _thusdToBurn) external;

    function setAddresses(
        address _thusdTokenAddress, 
        address _borrowerOperations, 
        address payable _bammAddress,
        address _collateralERC20
    ) external;
    function initialize() external;

    function depositToBAMM(uint256 _thusdAmount) external;
    function withdrawFromBAMM(uint256 _numShares) external;
    function withdrawTHUSD(address _recipient, uint256 _thusdAmount) external;
    function withdrawCollateral(address _recipient, uint256 _collateralAmount) external;

    function addRecipientToWhitelist(address _recipient) external;
    function addRecipientsToWhitelist(address[] calldata _recipients) external;
    function removeRecipientFromWhitelist(address _recipient) external;
    function removeRecipientsFromWhitelist(address[] calldata _recipients) external;

    function startChangingRoles(address _council, address _treasury) external;
    function cancelChangingRoles() external;
    function finalizeChangingRoles() external;
    
    function collateralERC20() external view returns(IERC20);
    function thusdToken() external view returns(ITHUSDToken);

}

// File: contracts/Interfaces/IPriceFeed.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.17;

interface IPriceFeed {

    // --- Events ---
    event LastGoodPriceUpdated(uint256 _lastGoodPrice);
   
    // --- Function ---
    function fetchPrice() external returns (uint);
}

// File: contracts/Interfaces/ISortedTroves.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.17;

// Common interface for the SortedTroves Doubly Linked List.
interface ISortedTroves {

    // --- Events ---
    
    event SortedTrovesAddressChanged(address _sortedDoublyLLAddress);
    event BorrowerOperationsAddressChanged(address _borrowerOperationsAddress);
    event NodeAdded(address _id, uint256 _NICR);
    event NodeRemoved(address _id);

    // --- Functions ---
    
    function setParams(uint256 _size, address _TroveManagerAddress, address _borrowerOperationsAddress) external;

    function insert(address _id, uint256 _ICR, address _prevId, address _nextId) external;

    function remove(address _id) external;

    function reInsert(address _id, uint256 _newICR, address _prevId, address _nextId) external;

    function contains(address _id) external view returns (bool);

    function isFull() external view returns (bool);

    function isEmpty() external view returns (bool);

    function getSize() external view returns (uint256);

    function getMaxSize() external view returns (uint256);

    function getFirst() external view returns (address);

    function getLast() external view returns (address);

    function getNext(address _id) external view returns (address);

    function getPrev(address _id) external view returns (address);

    function validInsertPosition(uint256 _ICR, address _prevId, address _nextId) external view returns (bool);

    function findInsertPosition(uint256 _ICR, address _prevId, address _nextId) external view returns (address, address);
}

// File: contracts/Interfaces/IStabilityPool.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.17;

/*
 * The Stability Pool holds THUSD tokens deposited by Stability Pool depositors.
 *
 * When a trove is liquidated, then depending on system conditions, some of its THUSD debt gets offset with
 * THUSD in the Stability Pool:  that is, the offset debt evaporates, and an equal amount of THUSD tokens in the Stability Pool is burned.
 *
 * Thus, a liquidation causes each depositor to receive a THUSD loss, in proportion to their deposit as a share of total deposits.
 * They also receive an collateral gain, as the collateral of the liquidated trove is distributed among Stability depositors,
 * in the same proportion.
 *
 * When a liquidation occurs, it depletes every deposit by the same fraction: for example, a liquidation that depletes 40%
 * of the total THUSD in the Stability Pool, depletes 40% of each deposit.
 *
 * A deposit that has experienced a series of liquidations is termed a "compounded deposit": each liquidation depletes the deposit,
 * multiplying it by some factor in range ]0,1[
 *
 * Please see the implementation spec in the proof document, which closely follows on from the compounded deposit / collateral gain derivations:
 * https://github.com/liquity/liquity/blob/master/papers/Scalable_Reward_Distribution_with_Compounding_Stakes.pdf
 *
 */
interface IStabilityPool {

    // --- Events ---

    event StabilityPoolCollateralBalanceUpdated(uint256 _newBalance);
    event StabilityPoolTHUSDBalanceUpdated(uint256 _newBalance);

    event BorrowerOperationsAddressChanged(address _newBorrowerOperationsAddress);
    event TroveManagerAddressChanged(address _newTroveManagerAddress);
    event ActivePoolAddressChanged(address _newActivePoolAddress);
    event DefaultPoolAddressChanged(address _newDefaultPoolAddress);
    event THUSDTokenAddressChanged(address _newTHUSDTokenAddress);
    event SortedTrovesAddressChanged(address _newSortedTrovesAddress);
    event PriceFeedAddressChanged(address _newPriceFeedAddress);
    event CollateralAddressChanged(address _newCollateralAddress);

    event P_Updated(uint256 _P);
    event S_Updated(uint256 _S, uint128 _epoch, uint128 _scale);
    event EpochUpdated(uint128 _currentEpoch);
    event ScaleUpdated(uint128 _currentScale);

    event DepositSnapshotUpdated(address indexed _depositor, uint256 _P, uint256 _S);
    event UserDepositChanged(address indexed _depositor, uint256 _newDeposit);

    event CollateralGainWithdrawn(address indexed _depositor, uint256 _collateral, uint256 _THUSDLoss);
    event CollateralSent(address _to, uint256 _amount);

    // --- Functions ---

    /*
     * Called only once on init, to set addresses of other Liquity contracts
     * Callable only by owner, renounces ownership at the end
     */
    function setAddresses(
        address _borrowerOperationsAddress,
        address _troveManagerAddress,
        address _activePoolAddress,
        address _thusdTokenAddress,
        address _sortedTrovesAddress,
        address _priceFeedAddress,
        address _collateralAddress
    ) external;

    /*
     * Initial checks:
     * - _amount is not zero
     * ---
     * - Sends depositor's accumulated gains (collateral) to depositor
     */
    function provideToSP(uint256 _amount) external;

    /*
     * Initial checks:
     * - _amount is zero or there are no under collateralized troves left in the system
     * - User has a non zero deposit
     * ---
     * - Sends all depositor's accumulated gains (collateral) to depositor
     * - Decreases deposit stake, and takes new snapshot.
     *
     * If _amount > userDeposit, the user withdraws all of their compounded deposit.
     */
    function withdrawFromSP(uint256 _amount) external;

    /*
     * Initial checks:
     * - User has a non zero deposit
     * - User has an open trove
     * - User has some collateral gain
     * ---
     * - Transfers the depositor's entire collateral gain from the Stability Pool to the caller's trove
     * - Leaves their compounded deposit in the Stability Pool
     * - Updates snapshots for deposit
     */
    function withdrawCollateralGainToTrove(address _upperHint, address _lowerHint) external;

    /*
     * Initial checks:
     * - Caller is TroveManager
     * ---
     * Cancels out the specified debt against the THUSD contained in the Stability Pool (as far as possible)
     * and transfers the Trove's collateral from ActivePool to StabilityPool.
     * Only called by liquidation functions in the TroveManager.
     */
    function offset(uint256 _debt, uint256 _coll) external;

    /*
     * Returns the total amount of collateral held by the pool, accounted in an internal variable instead of `balance`,
     * to exclude edge cases like collateral received from a self-destruct.
     */
    function getCollateralBalance() external view returns (uint);

    /*
     * Returns THUSD held in the pool. Changes when users deposit/withdraw, and when Trove debt is offset.
     */
    function getTotalTHUSDDeposits() external view returns (uint);

    /*
     * Calculates the collateral gain earned by the deposit since its last snapshots were taken.
     */
    function getDepositorCollateralGain(address _depositor) external view returns (uint);

    /*
     * Return the user's compounded deposit.
     */
    function getCompoundedTHUSDDeposit(address _depositor) external view returns (uint);

    /*
     * Only callable by Active Pool, updates ERC20 tokens recieved
     */
    function updateCollateralBalance(uint256 _amount) external;
    /*
     * Fallback function
     * Only callable by Active Pool, it just accounts for ETH received
     * receive() external payable;
     */
    
    function collateralAddress() external view returns(address);
}

// File: contracts/Interfaces/ITHUSDToken.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.17;

import "@openzeppelin/contracts/token/ERC20/extensions/IERC20Metadata.sol";
import "../Dependencies/IERC2612.sol";

interface ITHUSDToken is IERC20Metadata, IERC2612 {

    // --- Events ---

    event TroveManagerAddressAdded(address _troveManagerAddress);
    event StabilityPoolAddressAdded(address _newStabilityPoolAddress);
    event BorrowerOperationsAddressAdded(address _newBorrowerOperationsAddress);

    event THUSDTokenBalanceUpdated(address _user, uint256 _amount);

    // --- Functions ---
    function mintList(address contractAddress) external view returns (bool);
    function burnList(address contractAddress) external view returns (bool);

    function mint(address _account, uint256 _amount) external;

    function burn(address _account, uint256 _amount) external;

    function increaseAllowance(address spender, uint256 addedValue) external returns (bool);

    function decreaseAllowance(address spender, uint256 subtractedValue) external returns (bool);
}

// File: contracts/Interfaces/ITroveManager.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.17;

import "./ILiquityBase.sol";
import "./IStabilityPool.sol";
import "./ITHUSDToken.sol";
import "./IPCV.sol";


// Common interface for the Trove Manager.
interface ITroveManager is ILiquityBase {

    enum Status {
        nonExistent,
        active,
        closedByOwner,
        closedByLiquidation,
        closedByRedemption
    }

    // --- Events ---

    event BorrowerOperationsAddressChanged(address _newBorrowerOperationsAddress);
    event PriceFeedAddressChanged(address _newPriceFeedAddress);
    event THUSDTokenAddressChanged(address _newTHUSDTokenAddress);
    event ActivePoolAddressChanged(address _activePoolAddress);
    event DefaultPoolAddressChanged(address _defaultPoolAddress);
    event StabilityPoolAddressChanged(address _stabilityPoolAddress);
    event GasPoolAddressChanged(address _gasPoolAddress);
    event CollSurplusPoolAddressChanged(address _collSurplusPoolAddress);
    event SortedTrovesAddressChanged(address _sortedTrovesAddress);
    event PCVAddressChanged(address _pcvAddress);

    event Liquidation(uint256 _liquidatedDebt, uint256 _liquidatedColl, uint256 _collGasCompensation, uint256 _THUSDGasCompensation);
    event Redemption(uint256 _attemptedTHUSDAmount, uint256 _actualTHUSDAmount, uint256 _collateralSent, uint256 _collateralFee);
    event TroveUpdated(address indexed _borrower, uint256 _debt, uint256 _coll, uint256 stake, uint8 operation);
    event TroveLiquidated(address indexed _borrower, uint256 _debt, uint256 _coll, uint8 operation);
    event BaseRateUpdated(uint256 _baseRate);
    event LastFeeOpTimeUpdated(uint256 _lastFeeOpTime);
    event TotalStakesUpdated(uint256 _newTotalStakes);
    event SystemSnapshotsUpdated(uint256 _totalStakesSnapshot, uint256 _totalCollateralSnapshot);
    event LTermsUpdated(uint256 _L_Collateral, uint256 _L_THUSDDebt);
    event TroveSnapshotsUpdated(uint256 _L_Collateral, uint256 _L_THUSDDebt);
    event TroveIndexUpdated(address _borrower, uint256 _newIndex);

    // --- Functions ---

    function setAddresses(
        address _borrowerOperationsAddress,
        address _activePoolAddress,
        address _defaultPoolAddress,
        address _stabilityPoolAddress,
        address _gasPoolAddress,
        address _collSurplusPoolAddress,
        address _priceFeedAddress,
        address _thusdTokenAddress,
        address _sortedTrovesAddress,
        address _pcvAddress
    ) external;

    function stabilityPool() external view returns (IStabilityPool);
    function thusdToken() external view returns (ITHUSDToken);
    function pcv() external view returns (IPCV);

    function getTroveOwnersCount() external view returns (uint);

    function getTroveFromTroveOwnersArray(uint256 _index) external view returns (address);

    function getNominalICR(address _borrower) external view returns (uint);
    function getCurrentICR(address _borrower, uint256 _price) external view returns (uint);

    function liquidate(address _borrower) external;

    function liquidateTroves(uint256 _n) external;

    function batchLiquidateTroves(address[] calldata _troveArray) external;

    function redeemCollateral(
        uint256 _THUSDAmount,
        address _firstRedemptionHint,
        address _upperPartialRedemptionHint,
        address _lowerPartialRedemptionHint,
        uint256 _partialRedemptionHintNICR,
        uint256 _maxIterations,
        uint256 _maxFee
    ) external;

    function updateStakeAndTotalStakes(address _borrower) external returns (uint);

    function updateTroveRewardSnapshots(address _borrower) external;

    function addTroveOwnerToArray(address _borrower) external returns (uint256 index);

    function applyPendingRewards(address _borrower) external;

    function getPendingCollateralReward(address _borrower) external view returns (uint);

    function getPendingTHUSDDebtReward(address _borrower) external view returns (uint);

     function hasPendingRewards(address _borrower) external view returns (bool);

    function getEntireDebtAndColl(address _borrower) external view returns (
        uint256 debt,
        uint256 coll,
        uint256 pendingTHUSDDebtReward,
        uint256 pendingCollateralReward
    );

    function closeTrove(address _borrower) external;

    function removeStake(address _borrower) external;

    function getRedemptionRate() external view returns (uint);
    function getRedemptionRateWithDecay() external view returns (uint);

    function getRedemptionFeeWithDecay(uint256 _collateralDrawn) external view returns (uint);

    function getBorrowingRate() external view returns (uint);
    function getBorrowingRateWithDecay() external view returns (uint);

    function getBorrowingFee(uint256 THUSDDebt) external view returns (uint);
    function getBorrowingFeeWithDecay(uint256 _THUSDDebt) external view returns (uint);

    function decayBaseRateFromBorrowing() external;

    function getTroveStatus(address _borrower) external view returns (Status);

    function getTroveStake(address _borrower) external view returns (uint);

    function getTroveDebt(address _borrower) external view returns (uint);

    function getTroveColl(address _borrower) external view returns (uint);

    function setTroveStatus(address _borrower, Status _status) external;

    function increaseTroveColl(address _borrower, uint256 _collIncrease) external returns (uint);

    function decreaseTroveColl(address _borrower, uint256 _collDecrease) external returns (uint);

    function increaseTroveDebt(address _borrower, uint256 _debtIncrease) external returns (uint);

    function decreaseTroveDebt(address _borrower, uint256 _collDecrease) external returns (uint);

    function getTCR(uint256 _price) external view returns (uint);

    function checkRecoveryMode(uint256 _price) external view returns (bool);
}

// File: contracts/SortedTroves.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.17;

import "./Interfaces/ISortedTroves.sol";
import "./Interfaces/ITroveManager.sol";
import "./Interfaces/IBorrowerOperations.sol";
import "./Dependencies/Ownable.sol";
import "./Dependencies/CheckContract.sol";

/*
* A sorted doubly linked list with nodes sorted in descending order.
*
* Nodes map to active Troves in the system - the ID property is the address of a Trove owner.
* Nodes are ordered according to their current nominal individual collateral ratio (NICR),
* which is like the ICR but without the price, i.e., just collateral / debt.
*
* The list optionally accepts insert position hints.
*
* NICRs are computed dynamically at runtime, and not stored on the Node. This is because NICRs of active Troves
* change dynamically as liquidation events occur.
*
* The list relies on the fact that liquidation events preserve ordering: a liquidation decreases the NICRs of all active Troves,
* but maintains their order. A node inserted based on current NICR will maintain the correct position,
* relative to it's peers, as rewards accumulate, as long as it's raw collateral and debt have not changed.
* Thus, Nodes remain sorted by current NICR.
*
* Nodes need only be re-inserted upon a Trove operation - when the owner adds or removes collateral or debt
* to their position.
*
* The list is a modification of the following audited SortedDoublyLinkedList:
* https://github.com/livepeer/protocol/blob/master/contracts/libraries/SortedDoublyLL.sol
*
*
* Changes made in the Liquity implementation:
*
* - Keys have been removed from nodes
*
* - Ordering checks for insertion are performed by comparing an NICR argument to the current NICR, calculated at runtime.
*   The list relies on the property that ordering by ICR is maintained as the collateral:USD price varies.
*
* - Public functions with parameters have been made internal to save gas, and given an external wrapper function for external access
*/
contract SortedTroves is Ownable, CheckContract, ISortedTroves {

    string constant public NAME = "SortedTroves";

    event TroveManagerAddressChanged(address _troveManagerAddress);

    address public borrowerOperationsAddress;

    ITroveManager public troveManager;

    // Information for a node in the list
    struct Node {
        bool exists;
        address nextId;                  // Id of next node (smaller NICR) in the list
        address prevId;                  // Id of previous node (larger NICR) in the list
    }

    // Information for the list
    struct Data {
        address head;                        // Head of the list. Also the node in the list with the largest NICR
        address tail;                        // Tail of the list. Also the node in the list with the smallest NICR
        uint256 maxSize;                     // Maximum size of the list
        uint256 size;                        // Current size of the list
        mapping (address => Node) nodes;     // Track the corresponding ids for each node in the list
    }

    Data public data;

    // --- Dependency setters ---

    function setParams(uint256 _size, address _troveManagerAddress, address _borrowerOperationsAddress) external override onlyOwner {
        require(_size > 0, "SortedTroves: Size cant be zero");
        checkContract(_troveManagerAddress);
        checkContract(_borrowerOperationsAddress);

        data.maxSize = _size;

        troveManager = ITroveManager(_troveManagerAddress);
        borrowerOperationsAddress = _borrowerOperationsAddress;

        emit TroveManagerAddressChanged(_troveManagerAddress);
        emit BorrowerOperationsAddressChanged(_borrowerOperationsAddress);

        _renounceOwnership();
    }

    /*
     * @dev Add a node to the list
     * @param _id Node's id
     * @param _NICR Node's NICR
     * @param _prevId Id of previous node for the insert position
     * @param _nextId Id of next node for the insert position
     */

    function insert (address _id, uint256 _NICR, address _prevId, address _nextId) external override {
        ITroveManager troveManagerCached = troveManager;

        _requireCallerIsBOorTroveM(troveManagerCached);
        _insert(troveManagerCached, _id, _NICR, _prevId, _nextId);
    }

    function _insert(ITroveManager _troveManager, address _id, uint256 _NICR, address _prevId, address _nextId) internal {
        // List must not be full
        require(!isFull(), "SortedTroves: List is full");
        // List must not already contain node
        require(!contains(_id), "SortedTroves: List already contains the node");
        // Node id must not be null
        require(_id != address(0), "SortedTroves: Id cannot be zero");
        // NICR must be non-zero
        require(_NICR > 0, "SortedTroves: NICR must be positive");

        address prevId = _prevId;
        address nextId = _nextId;

        if (!_validInsertPosition(_troveManager, _NICR, prevId, nextId)) {
            // Sender's hint was not a valid insert position
            // Use sender's hint to find a valid insert position
            (prevId, nextId) = _findInsertPosition(_troveManager, _NICR, prevId, nextId);
        }

         data.nodes[_id].exists = true;

        if (prevId == address(0) && nextId == address(0)) {
            // Insert as head and tail
            data.head = _id;
            data.tail = _id;
        } else if (prevId == address(0)) {
            // Insert before `prevId` as the head
            data.nodes[_id].nextId = data.head;
            data.nodes[data.head].prevId = _id;
            data.head = _id;
        } else if (nextId == address(0)) {
            // Insert after `nextId` as the tail
            data.nodes[_id].prevId = data.tail;
            data.nodes[data.tail].nextId = _id;
            data.tail = _id;
        } else {
            // Insert at insert position between `prevId` and `nextId`
            data.nodes[_id].nextId = nextId;
            data.nodes[_id].prevId = prevId;
            data.nodes[prevId].nextId = _id;
            data.nodes[nextId].prevId = _id;
        }

        data.size += 1;
        emit NodeAdded(_id, _NICR);
    }

    function remove(address _id) external override {
        _requireCallerIsTroveManager();
        _remove(_id);
    }

    /*
     * @dev Remove a node from the list
     * @param _id Node's id
     */
    function _remove(address _id) internal {
        // List must contain the node
        require(contains(_id), "SortedTroves: List does not contain the id");

        if (data.size > 1) {
            // List contains more than a single node
            if (_id == data.head) {
                // The removed node is the head
                // Set head to next node
                data.head = data.nodes[_id].nextId;
                // Set prev pointer of new head to null
                data.nodes[data.head].prevId = address(0);
            } else if (_id == data.tail) {
                // The removed node is the tail
                // Set tail to previous node
                data.tail = data.nodes[_id].prevId;
                // Set next pointer of new tail to null
                data.nodes[data.tail].nextId = address(0);
            } else {
                // The removed node is neither the head nor the tail
                // Set next pointer of previous node to the next node
                data.nodes[data.nodes[_id].prevId].nextId = data.nodes[_id].nextId;
                // Set prev pointer of next node to the previous node
                data.nodes[data.nodes[_id].nextId].prevId = data.nodes[_id].prevId;
            }
        } else {
            // List contains a single node
            // Set the head and tail to null
            data.head = address(0);
            data.tail = address(0);
        }

        delete data.nodes[_id];
        data.size -= 1;
        emit NodeRemoved(_id);
    }

    /*
     * @dev Re-insert the node at a new position, based on its new NICR
     * @param _id Node's id
     * @param _newNICR Node's new NICR
     * @param _prevId Id of previous node for the new insert position
     * @param _nextId Id of next node for the new insert position
     */
    function reInsert(address _id, uint256 _newNICR, address _prevId, address _nextId) external override {
        ITroveManager troveManagerCached = troveManager;

        _requireCallerIsBOorTroveM(troveManagerCached);
        // List must contain the node
        require(contains(_id), "SortedTroves: List does not contain the id");
        // NICR must be non-zero
        require(_newNICR > 0, "SortedTroves: NICR must be positive");

        // Remove node from the list
        _remove(_id);

        _insert(troveManagerCached, _id, _newNICR, _prevId, _nextId);
    }

    /*
     * @dev Checks if the list contains a node
     */
    function contains(address _id) public view override returns (bool) {
        return data.nodes[_id].exists;
    }

    /*
     * @dev Checks if the list is full
     */
    function isFull() public view override returns (bool) {
        return data.size == data.maxSize;
    }

    /*
     * @dev Checks if the list is empty
     */
    function isEmpty() public view override returns (bool) {
        return data.size == 0;
    }

    /*
     * @dev Returns the current size of the list
     */
    function getSize() external view override returns (uint256) {
        return data.size;
    }

    /*
     * @dev Returns the maximum size of the list
     */
    function getMaxSize() external view override returns (uint256) {
        return data.maxSize;
    }

    /*
     * @dev Returns the first node in the list (node with the largest NICR)
     */
    function getFirst() external view override returns (address) {
        return data.head;
    }

    /*
     * @dev Returns the last node in the list (node with the smallest NICR)
     */
    function getLast() external view override returns (address) {
        return data.tail;
    }

    /*
     * @dev Returns the next node (with a smaller NICR) in the list for a given node
     * @param _id Node's id
     */
    function getNext(address _id) external view override returns (address) {
        return data.nodes[_id].nextId;
    }

    /*
     * @dev Returns the previous node (with a larger NICR) in the list for a given node
     * @param _id Node's id
     */
    function getPrev(address _id) external view override returns (address) {
        return data.nodes[_id].prevId;
    }

    /*
     * @dev Check if a pair of nodes is a valid insertion point for a new node with the given NICR
     * @param _NICR Node's NICR
     * @param _prevId Id of previous node for the insert position
     * @param _nextId Id of next node for the insert position
     */
    function validInsertPosition(uint256 _NICR, address _prevId, address _nextId) external view override returns (bool) {
        return _validInsertPosition(troveManager, _NICR, _prevId, _nextId);
    }

    function _validInsertPosition(ITroveManager _troveManager, uint256 _NICR, address _prevId, address _nextId) internal view returns (bool) {
        if (_prevId == address(0) && _nextId == address(0)) {
            // `(null, null)` is a valid insert position if the list is empty
            return isEmpty();
        } else if (_prevId == address(0)) {
            // `(null, _nextId)` is a valid insert position if `_nextId` is the head of the list
            return data.head == _nextId && _NICR >= _troveManager.getNominalICR(_nextId);
        } else if (_nextId == address(0)) {
            // `(_prevId, null)` is a valid insert position if `_prevId` is the tail of the list
            return data.tail == _prevId && _NICR <= _troveManager.getNominalICR(_prevId);
        } else {
            // `(_prevId, _nextId)` is a valid insert position if they are adjacent nodes and `_NICR` falls between the two nodes' NICRs
            return data.nodes[_prevId].nextId == _nextId &&
                   _troveManager.getNominalICR(_prevId) >= _NICR &&
                   _NICR >= _troveManager.getNominalICR(_nextId);
        }
    }

    /*
     * @dev Descend the list (larger NICRs to smaller NICRs) to find a valid insert position
     * @param _troveManager TroveManager contract, passed in as param to save SLOAD’s
     * @param _NICR Node's NICR
     * @param _startId Id of node to start descending the list from
     */
    function _descendList(ITroveManager _troveManager, uint256 _NICR, address _startId) internal view returns (address, address) {
        // If `_startId` is the head, check if the insert position is before the head
        if (data.head == _startId && _NICR >= _troveManager.getNominalICR(_startId)) {
            return (address(0), _startId);
        }

        address prevId = _startId;
        address nextId = data.nodes[prevId].nextId;

        // Descend the list until we reach the end or until we find a valid insert position
        while (prevId != address(0) && !_validInsertPosition(_troveManager, _NICR, prevId, nextId)) {
            prevId = data.nodes[prevId].nextId;
            nextId = data.nodes[prevId].nextId;
        }

        return (prevId, nextId);
    }

    /*
     * @dev Ascend the list (smaller NICRs to larger NICRs) to find a valid insert position
     * @param _troveManager TroveManager contract, passed in as param to save SLOAD’s
     * @param _NICR Node's NICR
     * @param _startId Id of node to start ascending the list from
     */
    function _ascendList(ITroveManager _troveManager, uint256 _NICR, address _startId) internal view returns (address, address) {
        // If `_startId` is the tail, check if the insert position is after the tail
        if (data.tail == _startId && _NICR <= _troveManager.getNominalICR(_startId)) {
            return (_startId, address(0));
        }

        address nextId = _startId;
        address prevId = data.nodes[nextId].prevId;

        // Ascend the list until we reach the end or until we find a valid insertion point
        while (nextId != address(0) && !_validInsertPosition(_troveManager, _NICR, prevId, nextId)) {
            nextId = data.nodes[nextId].prevId;
            prevId = data.nodes[nextId].prevId;
        }

        return (prevId, nextId);
    }

    /*
     * @dev Find the insert position for a new node with the given NICR
     * @param _NICR Node's NICR
     * @param _prevId Id of previous node for the insert position
     * @param _nextId Id of next node for the insert position
     */
    function findInsertPosition(uint256 _NICR, address _prevId, address _nextId) external view override returns (address, address) {
        return _findInsertPosition(troveManager, _NICR, _prevId, _nextId);
    }

    function _findInsertPosition(ITroveManager _troveManager, uint256 _NICR, address _prevId, address _nextId) internal view returns (address, address) {
        address prevId = _prevId;
        address nextId = _nextId;

        if (prevId != address(0)) {
            if (!contains(prevId) || _NICR > _troveManager.getNominalICR(prevId)) {
                // `prevId` does not exist anymore or now has a smaller NICR than the given NICR
                prevId = address(0);
            }
        }

        if (nextId != address(0)) {
            if (!contains(nextId) || _NICR < _troveManager.getNominalICR(nextId)) {
                // `nextId` does not exist anymore or now has a larger NICR than the given NICR
                nextId = address(0);
            }
        }

        if (prevId == address(0) && nextId == address(0)) {
            // No hint - descend list starting from head
            return _descendList(_troveManager, _NICR, data.head);
        } else if (prevId == address(0)) {
            // No `prevId` for hint - ascend list starting from `nextId`
            return _ascendList(_troveManager, _NICR, nextId);
        } else if (nextId == address(0)) {
            // No `nextId` for hint - descend list starting from `prevId`
            return _descendList(_troveManager, _NICR, prevId);
        } else {
            // Descend list starting from `prevId`
            return _descendList(_troveManager, _NICR, prevId);
        }
    }

    // --- 'require' functions ---

    function _requireCallerIsTroveManager() internal view {
        require(msg.sender == address(troveManager), "SortedTroves: Caller is not the TroveManager");
    }

    function _requireCallerIsBOorTroveM(ITroveManager _troveManager) internal view {
        require(msg.sender == borrowerOperationsAddress || msg.sender == address(_troveManager),
                "SortedTroves: Caller is neither BO nor TroveM");
    }
}