// 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 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: @openzeppelin/contracts/utils/math/Math.sol



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

pragma solidity ^0.8.0;

/**
 * @dev Standard math utilities missing in the Solidity language.
 */
library Math {
    /**
     * @dev Returns the largest of two numbers.
     */
    function max(uint256 a, uint256 b) internal pure returns (uint256) {
        return a >= b ? a : b;
    }

    /**
     * @dev Returns the smallest of two numbers.
     */
    function min(uint256 a, uint256 b) internal pure returns (uint256) {
        return a < b ? a : b;
    }

    /**
     * @dev Returns the average of two numbers. The result is rounded towards
     * zero.
     */
    function average(uint256 a, uint256 b) internal pure returns (uint256) {
        // (a + b) / 2 can overflow.
        return (a & b) + (a ^ b) / 2;
    }

    /**
     * @dev Returns the ceiling of the division of two numbers.
     *
     * This differs from standard division with `/` in that it rounds up instead
     * of rounding down.
     */
    function ceilDiv(uint256 a, uint256 b) internal pure returns (uint256) {
        // (a + b - 1) / b can overflow on addition, so we distribute.
        return a / b + (a % b == 0 ? 0 : 1);
    }
}

// File: @openzeppelin/contracts/utils/math/SafeCast.sol



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

pragma solidity ^0.8.0;

/**
 * @dev Wrappers over Solidity's uintXX/intXX casting operators with added overflow
 * checks.
 *
 * Downcasting from uint256/int256 in Solidity does not revert on overflow. This can
 * easily result in undesired exploitation or bugs, since developers usually
 * assume that overflows raise errors. `SafeCast` restores this intuition by
 * reverting the transaction when such an operation overflows.
 *
 * Using this library instead of the unchecked operations eliminates an entire
 * class of bugs, so it's recommended to use it always.
 *
 * Can be combined with {SafeMath} and {SignedSafeMath} to extend it to smaller types, by performing
 * all math on `uint256` and `int256` and then downcasting.
 */
library SafeCast {
    /**
     * @dev Returns the downcasted uint224 from uint256, reverting on
     * overflow (when the input is greater than largest uint224).
     *
     * Counterpart to Solidity's `uint224` operator.
     *
     * Requirements:
     *
     * - input must fit into 224 bits
     */
    function toUint224(uint256 value) internal pure returns (uint224) {
        require(value <= type(uint224).max, "SafeCast: value doesn't fit in 224 bits");
        return uint224(value);
    }

    /**
     * @dev Returns the downcasted uint128 from uint256, reverting on
     * overflow (when the input is greater than largest uint128).
     *
     * Counterpart to Solidity's `uint128` operator.
     *
     * Requirements:
     *
     * - input must fit into 128 bits
     */
    function toUint128(uint256 value) internal pure returns (uint128) {
        require(value <= type(uint128).max, "SafeCast: value doesn't fit in 128 bits");
        return uint128(value);
    }

    /**
     * @dev Returns the downcasted uint96 from uint256, reverting on
     * overflow (when the input is greater than largest uint96).
     *
     * Counterpart to Solidity's `uint96` operator.
     *
     * Requirements:
     *
     * - input must fit into 96 bits
     */
    function toUint96(uint256 value) internal pure returns (uint96) {
        require(value <= type(uint96).max, "SafeCast: value doesn't fit in 96 bits");
        return uint96(value);
    }

    /**
     * @dev Returns the downcasted uint64 from uint256, reverting on
     * overflow (when the input is greater than largest uint64).
     *
     * Counterpart to Solidity's `uint64` operator.
     *
     * Requirements:
     *
     * - input must fit into 64 bits
     */
    function toUint64(uint256 value) internal pure returns (uint64) {
        require(value <= type(uint64).max, "SafeCast: value doesn't fit in 64 bits");
        return uint64(value);
    }

    /**
     * @dev Returns the downcasted uint32 from uint256, reverting on
     * overflow (when the input is greater than largest uint32).
     *
     * Counterpart to Solidity's `uint32` operator.
     *
     * Requirements:
     *
     * - input must fit into 32 bits
     */
    function toUint32(uint256 value) internal pure returns (uint32) {
        require(value <= type(uint32).max, "SafeCast: value doesn't fit in 32 bits");
        return uint32(value);
    }

    /**
     * @dev Returns the downcasted uint16 from uint256, reverting on
     * overflow (when the input is greater than largest uint16).
     *
     * Counterpart to Solidity's `uint16` operator.
     *
     * Requirements:
     *
     * - input must fit into 16 bits
     */
    function toUint16(uint256 value) internal pure returns (uint16) {
        require(value <= type(uint16).max, "SafeCast: value doesn't fit in 16 bits");
        return uint16(value);
    }

    /**
     * @dev Returns the downcasted uint8 from uint256, reverting on
     * overflow (when the input is greater than largest uint8).
     *
     * Counterpart to Solidity's `uint8` operator.
     *
     * Requirements:
     *
     * - input must fit into 8 bits.
     */
    function toUint8(uint256 value) internal pure returns (uint8) {
        require(value <= type(uint8).max, "SafeCast: value doesn't fit in 8 bits");
        return uint8(value);
    }

    /**
     * @dev Converts a signed int256 into an unsigned uint256.
     *
     * Requirements:
     *
     * - input must be greater than or equal to 0.
     */
    function toUint256(int256 value) internal pure returns (uint256) {
        require(value >= 0, "SafeCast: value must be positive");
        return uint256(value);
    }

    /**
     * @dev Returns the downcasted int128 from int256, reverting on
     * overflow (when the input is less than smallest int128 or
     * greater than largest int128).
     *
     * Counterpart to Solidity's `int128` operator.
     *
     * Requirements:
     *
     * - input must fit into 128 bits
     *
     * _Available since v3.1._
     */
    function toInt128(int256 value) internal pure returns (int128) {
        require(value >= type(int128).min && value <= type(int128).max, "SafeCast: value doesn't fit in 128 bits");
        return int128(value);
    }

    /**
     * @dev Returns the downcasted int64 from int256, reverting on
     * overflow (when the input is less than smallest int64 or
     * greater than largest int64).
     *
     * Counterpart to Solidity's `int64` operator.
     *
     * Requirements:
     *
     * - input must fit into 64 bits
     *
     * _Available since v3.1._
     */
    function toInt64(int256 value) internal pure returns (int64) {
        require(value >= type(int64).min && value <= type(int64).max, "SafeCast: value doesn't fit in 64 bits");
        return int64(value);
    }

    /**
     * @dev Returns the downcasted int32 from int256, reverting on
     * overflow (when the input is less than smallest int32 or
     * greater than largest int32).
     *
     * Counterpart to Solidity's `int32` operator.
     *
     * Requirements:
     *
     * - input must fit into 32 bits
     *
     * _Available since v3.1._
     */
    function toInt32(int256 value) internal pure returns (int32) {
        require(value >= type(int32).min && value <= type(int32).max, "SafeCast: value doesn't fit in 32 bits");
        return int32(value);
    }

    /**
     * @dev Returns the downcasted int16 from int256, reverting on
     * overflow (when the input is less than smallest int16 or
     * greater than largest int16).
     *
     * Counterpart to Solidity's `int16` operator.
     *
     * Requirements:
     *
     * - input must fit into 16 bits
     *
     * _Available since v3.1._
     */
    function toInt16(int256 value) internal pure returns (int16) {
        require(value >= type(int16).min && value <= type(int16).max, "SafeCast: value doesn't fit in 16 bits");
        return int16(value);
    }

    /**
     * @dev Returns the downcasted int8 from int256, reverting on
     * overflow (when the input is less than smallest int8 or
     * greater than largest int8).
     *
     * Counterpart to Solidity's `int8` operator.
     *
     * Requirements:
     *
     * - input must fit into 8 bits.
     *
     * _Available since v3.1._
     */
    function toInt8(int256 value) internal pure returns (int8) {
        require(value >= type(int8).min && value <= type(int8).max, "SafeCast: value doesn't fit in 8 bits");
        return int8(value);
    }

    /**
     * @dev Converts an unsigned uint256 into a signed int256.
     *
     * Requirements:
     *
     * - input must be less than or equal to maxInt256.
     */
    function toInt256(uint256 value) internal pure returns (int256) {
        // Note: Unsafe cast below is okay because `type(int256).max` is guaranteed to be positive
        require(value <= uint256(type(int256).max), "SafeCast: value doesn't fit in an int256");
        return int256(value);
    }
}

// File: contracts/InterestRateModelV2.sol



// SPDX-License-Identifier: BUSL-1.1
pragma solidity 0.8.13;

import "./InterestRateModelXAI.sol";
import "./lib/EasyMathV2.sol";

interface IGenericInterestRateModel {
    function config(address _silo, address _asset) external view returns (IInterestRateModel.Config memory);
}

/// @title InterestRateModelV2
/// @notice Dynamic interest rate model implementation
/// @dev Model stores some Silo specific data. If model is replaced, it needs to set proper config after redeployment
/// for seamless service. Please refer to separate litepaper about model for design details.
/// @custom:security-contact security@silo.finance
contract InterestRateModelV2 is InterestRateModelXAI {
    using SafeCast for int256;
    using SafeCast for uint256;

    constructor(Config memory _config, address _owner) InterestRateModelXAI(_config) {
        if (_owner != address(0) && _owner != msg.sender) {
            transferOwnership(_owner);
        }
    }

    /// @dev migration method for models before InterestRateModelV2
    /// @param _silos array of Silos addresses for which config will be cloned
    /// @param _siloRepository SiloRepository addresses
    function migrationFromV1(address[] calldata _silos, ISiloRepository _siloRepository)
        external
        virtual
        onlyOwner
    {
        IInterestRateModel model;

        for (uint256 i; i < _silos.length;) {
            address[] memory assets = ISilo(_silos[i]).getAssets();

            if (address(model) == address(0)) {
                // assumption is that XAI is not first asset otherwise this optimisation will not work
                model = _siloRepository.getInterestRateModel(_silos[0], assets[0]);
            }

            for (uint256 j; j < assets.length;) {
                Config memory clonedConfig = IGenericInterestRateModel(address(model)).config(_silos[i], assets[j]);

                if (clonedConfig.uopt == 0) {
                    IInterestRateModel secondModel = _siloRepository.getInterestRateModel(_silos[i], assets[j]);
                    clonedConfig = IGenericInterestRateModel(address(secondModel)).config(_silos[i], assets[j]);
                }

                // in order not to clone empty config, check `uopt` - based on requirements it can not be 0
                if (clonedConfig.uopt != 0) {
                    // beta is divided by value of 4 for all configs, except stableLowCap, stableHighCap and bridgeXAI
                    // With current values of beta parameter, volatile assets will get their interest rate
                    // (proportional term) multiplied by 2 in one hour. Division of beta coefficient by 4 will result
                    // in changing time for to double from one hour to four hours, which will make the interest rate
                    // model behaviour less risky,
                    // If we will forget about integral term (which will have less impact in first hours of critical
                    // utilisation), proportional term will grow linear. It will double in first 4 hours,
                    // triple in 8, x4 in 12, etc.
                    if (clonedConfig.beta == 277777777777778) {
                        clonedConfig.beta = 69444444444444;
                    }

                    // when we `setConfig()` we call `accrueInterest()`
                    // we don't have to do it when we cloning, because config will not change
                    _setConfig(_silos[i], assets[j], clonedConfig);
                }

                unchecked { j++; }
            }

            unchecked { i++; }
        }
    }

    /// @inheritdoc IInterestRateModel
    function calculateCurrentInterestRate( // solhint-disable-line function-max-lines
        Config memory _c,
        uint256 _totalDeposits,
        uint256 _totalBorrowAmount,
        uint256 _interestRateTimestamp,
        uint256 _blockTimestamp
    ) public pure virtual override returns (uint256 rcur) {
        if (_interestRateTimestamp > _blockTimestamp) revert InvalidTimestamps();

        // struct for local vars to avoid "Stack too deep"
        LocalVarsRCur memory _l = LocalVarsRCur(0,0,0,0,0,0,false);

        (,,,_l.overflow) = calculateCompoundInterestRateWithOverflowDetection(
            _c,
            _totalDeposits,
            _totalBorrowAmount,
            _interestRateTimestamp,
            _blockTimestamp
        );

        if (_l.overflow) {
            return 0;
        }

        // There can't be an underflow in the subtraction because of the previous check
        unchecked {
            // T := t1 - t0 # length of time period in seconds
            _l.T = (_blockTimestamp - _interestRateTimestamp).toInt256();
        }

        _l.u = EasyMathV2.calculateUtilization(DP, _totalDeposits, _totalBorrowAmount).toInt256();
        _l.DP = int256(DP);

        if (_l.u > _c.ucrit) {
            // rp := kcrit *(1 + Tcrit + beta *T)*( u0 - ucrit )
            _l.rp = _c.kcrit * (_l.DP + _c.Tcrit + _c.beta * _l.T) / _l.DP * (_l.u - _c.ucrit) / _l.DP;
        } else {
            // rp := min (0, klow * (u0 - ulow ))
            _l.rp = _min(0, _c.klow * (_l.u - _c.ulow) / _l.DP);
        }

        // rlin := klin * u0 # lower bound between t0 and t1
        _l.rlin = _c.klin * _l.u / _l.DP;
        // ri := max(ri , rlin )
        _l.ri = _max(_c.ri, _l.rlin);
        // ri := max(ri + ki * (u0 - uopt ) * T, rlin )
        _l.ri = _max(_l.ri + _c.ki * (_l.u - _c.uopt) * _l.T / _l.DP, _l.rlin);
        // rcur := max (ri + rp , rlin ) # current per second interest rate
        rcur = (_max(_l.ri + _l.rp, _l.rlin)).toUint256();
        rcur *= 365 days;

        return _currentInterestRateCAP(rcur);
    }

    /// @inheritdoc IInterestRateModel
    function calculateCompoundInterestRateWithOverflowDetection( // solhint-disable-line function-max-lines
        Config memory _c,
        uint256 _totalDeposits,
        uint256 _totalBorrowAmount,
        uint256 _interestRateTimestamp,
        uint256 _blockTimestamp
    ) public pure virtual override returns (
        uint256 rcomp,
        int256 ri,
        int256 Tcrit, // solhint-disable-line var-name-mixedcase
        bool overflow
    ) {
        ri = _c.ri;
        Tcrit = _c.Tcrit;

        // struct for local vars to avoid "Stack too deep"
        LocalVarsRComp memory _l = LocalVarsRComp(0,0,0,0,0,0,0,0,0,0);

        if (_interestRateTimestamp > _blockTimestamp) revert InvalidTimestamps();

        // There can't be an underflow in the subtraction because of the previous check
        unchecked {
            // length of time period in seconds
            _l.T = (_blockTimestamp - _interestRateTimestamp).toInt256();
        }

        int256 _DP = int256(DP); // solhint-disable-line var-name-mixedcase

        _l.u = EasyMathV2.calculateUtilization(DP, _totalDeposits, _totalBorrowAmount).toInt256();

        // slopei := ki * (u0 - uopt )
        _l.slopei = _c.ki * (_l.u - _c.uopt) / _DP;

        if (_l.u > _c.ucrit) {
            // rp := kcrit * (1 + Tcrit) * (u0 - ucrit )
            _l.rp = _c.kcrit * (_DP + Tcrit) / _DP * (_l.u - _c.ucrit) / _DP;
            // slope := slopei + kcrit * beta * (u0 - ucrit )
            _l.slope = _l.slopei + _c.kcrit * _c.beta / _DP * (_l.u - _c.ucrit) / _DP;
            // Tcrit := Tcrit + beta * T
            Tcrit = Tcrit + _c.beta * _l.T;
        } else {
            // rp := min (0, klow * (u0 - ulow ))
            _l.rp = _min(0, _c.klow * (_l.u - _c.ulow) / _DP);
            // slope := slopei
            _l.slope = _l.slopei;
            // Tcrit := max (0, Tcrit - beta * T)
            Tcrit = _max(0, Tcrit - _c.beta * _l.T);
        }

        // rlin := klin * u0 # lower bound between t0 and t1
        _l.rlin = _c.klin * _l.u / _DP;
        // ri := max(ri , rlin )
        ri = _max(ri , _l.rlin);
        // r0 := ri + rp # interest rate at t0 ignoring lower bound
        _l.r0 = ri + _l.rp;
        // r1 := r0 + slope *T # what interest rate would be at t1 ignoring lower bound
        _l.r1 = _l.r0 + _l.slope * _l.T;

        // Calculating the compound interest

        if (_l.r0 >= _l.rlin && _l.r1 >= _l.rlin) {
            // lower bound isn’t activated
            // rcomp := exp (( r0 + r1) * T / 2) - 1
            _l.x = (_l.r0 + _l.r1) * _l.T / 2;
        } else if (_l.r0 < _l.rlin && _l.r1 < _l.rlin) {
            // lower bound is active during the whole time
            // rcomp := exp( rlin * T) - 1
            _l.x = _l.rlin * _l.T;
        } else if (_l.r0 >= _l.rlin && _l.r1 < _l.rlin) {
            // lower bound is active after some time
            // rcomp := exp( rlin *T - (r0 - rlin )^2/ slope /2) - 1
            _l.x = _l.rlin * _l.T - (_l.r0 - _l.rlin)**2 / _l.slope / 2;
        } else {
            // lower bound is active before some time
            // rcomp := exp( rlin *T + (r1 - rlin )^2/ slope /2) - 1
            _l.x = _l.rlin * _l.T + (_l.r1 - _l.rlin)**2 / _l.slope / 2;
        }

        // ri := max(ri + slopei * T, rlin )
        ri = _max(ri + _l.slopei * _l.T, _l.rlin);

        // Checking for the overflow below. In case of the overflow, ri and Tcrit will be set back to zeros. Rcomp is
        // calculated to not make an overflow in totalBorrowedAmount, totalDeposits.
        (rcomp, overflow) = _calculateRComp(_totalDeposits, _totalBorrowAmount, _l.x);

        // if we got a limit for rcomp, we reset Tcrit and Ri model parameters to zeros
        // Resetting parameters will make IR drop from 10k%/year to 100% per year and it will start growing again.
        // If we don’t reset, we will have to wait ~2 weeks to make IR drop (low utilisation ratio required).
        // So zeroing parameters is a only hope for a market to get well again, otherwise it will be almost impossible.
        bool capApplied;

        (rcomp, capApplied) = _compoundInterestRateCAP(rcomp, _l.T.toUint256());

        if (overflow || capApplied) {
            ri = 0;
            Tcrit = 0;
        }
    }

    /// @dev in order to keep methods pure and bee able to deploy easily new caps,
    /// that method with hardcoded CAP was created
    /// @notice limit for compounding interest rcomp := RCOMP_CAP * _l.T.
    /// The limit is simple. Let’s threat our interest rate model as the black box. And for past _l.T time we got
    /// a value for rcomp. We need to provide the top limit this value to take into account the limit for current
    /// interest. Let’s imagine, if we had maximum allowed interest for _l.T. `RCOMP_CAP * _l.T` will be the value of
    /// rcomp in this case, which will serve as the limit.
    /// If we got this limit, we should make Tcrit and Ri equal to zero, otherwise there is a low probability of the
    /// market going back below the limit.
    function _compoundInterestRateCAP(uint256 _rcomp, uint256 _t)
        internal
        pure
        virtual
        returns (uint256 updatedRcomp, bool capApplied) {
        // uint256 cap = 10**20 / (365 * 24 * 3600); // this is per-second rate because _l.T is in seconds.
        uint256 cap = 3170979198376 * _t;
        return _rcomp > cap ? (cap, true) : (_rcomp, false);
    }

    /// @notice limit for rcur - RCUR_CAP (FE/integrations, does not affect our protocol).
    /// This is the limit for current interest rate, we picked 10k% of interest per year. Interest rate model is working
    /// as expected before that threshold and simply sets the maximum value in case of limit.
    /// 10k% is a really significant threshold, which will mean the death of market in most of cases.
    /// Before 10k% interest rate can be good for certain market conditions.
    /// We don’t read the current interest rate in our protocol, because we care only about the interest we compounded
    /// over the past time since the last update. It is used in UI and other protocols integrations,
    /// for example investing strategies.
    function _currentInterestRateCAP(uint256 _rcur) internal pure virtual returns (uint256) {
        uint256 cap = 1e20; // 10**20; this is 10,000% APR in the 18-decimals format.
        return _rcur > cap ? cap : _rcur;
    }
}

// File: contracts/InterestRateModelXAI.sol



// SPDX-License-Identifier: BUSL-1.1
pragma solidity 0.8.13;

import "@openzeppelin/contracts/utils/math/SafeCast.sol";
import "@openzeppelin/contracts/utils/math/Math.sol";

import "./lib/PRBMathSD59x18.sol";
import "./lib/EasyMathV2.sol";
import "./interfaces/ISilo.sol";
import "./interfaces/IInterestRateModel.sol";
import "./utils/TwoStepOwnable.sol";

/// @title InterestRateModelXAI
/// @notice Dynamic interest rate model implementation
/// @dev Model stores some Silo specific data. If model is replaced, it needs to set proper config after redeployment
/// for seamless service. Please refer to separate litepaper about model for design details.
/// Difference between original `InterestRateModel` is that we made methods to be `virtual` and :
///     if (_config.ki < 0) revert InvalidKi();  --- was ... <= 0
//      if (_config.kcrit < 0) revert InvalidKcrit();  --- was ... <= 0
/// @custom:security-contact security@silo.finance
abstract contract InterestRateModelXAI is IInterestRateModel, TwoStepOwnable {
    using PRBMathSD59x18 for int256;
    using SafeCast for int256;
    using SafeCast for uint256;

    /// @dev DP is 18 decimal points used for integer calculations
    uint256 public constant override DP = 1e18;

    /// @dev maximum value of compound interest the model will return
    uint256 public constant RCOMP_MAX = (2**16) * 1e18;

    /// @dev maximum value of X for which, RCOMP_MAX should be returned. If x > X_MAX => exp(x) > RCOMP_MAX.
    /// X_MAX = ln(RCOMP_MAX + 1)
    int256 public constant X_MAX = 11090370147631773313;

    /// @dev maximum allowed amount for accruedInterest, totalDeposits and totalBorrowedAmount
    /// after adding compounded interest. If rcomp cause this values to overflow, rcomp is reduced.
    /// 196 bits max allowed for an asset amounts because the multiplication product with
    /// decimal points (10^18) should not cause an overflow. 196 < log2(2^256 / 10^18)
    uint256 public constant ASSET_DATA_OVERFLOW_LIMIT = 2**196;

    // Silo => asset => ModelData
    mapping(address => mapping(address => Config)) public config;

    /// @notice Emitted on config change
    /// @param silo Silo address for which config should be set
    /// @param asset asset address for which config should be set
    /// @param config config struct for asset in Silo
    event ConfigUpdate(address indexed silo, address indexed asset, Config config);

    error InvalidBeta();
    error InvalidKcrit();
    error InvalidKi();
    error InvalidKlin();
    error InvalidKlow();
    error InvalidTcrit();
    error InvalidTimestamps();
    error InvalidUcrit();
    error InvalidUlow();
    error InvalidUopt();
    error InvalidRi();

    constructor(Config memory _config) {
        _setConfig(address(0), address(0), _config);
    }

    /// @inheritdoc IInterestRateModel
    function setConfig(address _silo, address _asset, Config calldata _config) external virtual override onlyOwner {
        // we do not care, if accrueInterest call will be successful
        // solhint-disable-next-line avoid-low-level-calls
        _silo.call(abi.encodeCall(ISilo.accrueInterest, _asset));

        _setConfig(_silo, _asset, _config);
    }

    /// @inheritdoc IInterestRateModel
    function getCompoundInterestRateAndUpdate(
        address _asset,
        uint256 _blockTimestamp
    ) external virtual override returns (uint256 rcomp) {
        // assume that caller is Silo
        address silo = msg.sender;

        ISilo.UtilizationData memory data = ISilo(silo).utilizationData(_asset);

        // TODO when depositing, we doing two calls for `calculateCompoundInterestRate`, maybe we can optimize?
        Config storage currentConfig = config[silo][_asset];

        (rcomp, currentConfig.ri, currentConfig.Tcrit) = calculateCompoundInterestRate(
            getConfig(silo, _asset),
            data.totalDeposits,
            data.totalBorrowAmount,
            data.interestRateTimestamp,
            _blockTimestamp
        );
    }

    /// @inheritdoc IInterestRateModel
    function getCompoundInterestRate(
        address _silo,
        address _asset,
        uint256 _blockTimestamp
    ) external view virtual override returns (uint256 rcomp) {
        ISilo.UtilizationData memory data = ISilo(_silo).utilizationData(_asset);

        (rcomp,,) = calculateCompoundInterestRate(
            getConfig(_silo, _asset),
            data.totalDeposits,
            data.totalBorrowAmount,
            data.interestRateTimestamp,
            _blockTimestamp
        );
    }

    /// @inheritdoc IInterestRateModel
    function overflowDetected(
        address _silo,
        address _asset,
        uint256 _blockTimestamp
    ) external view virtual override returns (bool overflow) {
        ISilo.UtilizationData memory data = ISilo(_silo).utilizationData(_asset);

        (,,,overflow) = calculateCompoundInterestRateWithOverflowDetection(
            getConfig(_silo, _asset),
            data.totalDeposits,
            data.totalBorrowAmount,
            data.interestRateTimestamp,
            _blockTimestamp
        );
    }

    /// @inheritdoc IInterestRateModel
    function getCurrentInterestRate(
        address _silo,
        address _asset,
        uint256 _blockTimestamp
    ) external view virtual override returns (uint256 rcur) {
        ISilo.UtilizationData memory data = ISilo(_silo).utilizationData(_asset);

        rcur = calculateCurrentInterestRate(
            getConfig(_silo, _asset),
            data.totalDeposits,
            data.totalBorrowAmount,
            data.interestRateTimestamp,
            _blockTimestamp
        );
    }

    /// @inheritdoc IInterestRateModel
    function getConfig(address _silo, address _asset) public view virtual override returns (Config memory) {
        Config storage currentConfig = config[_silo][_asset];

        if (currentConfig.uopt != 0) {
            return currentConfig;
        }

        // use default config
        Config memory c = config[address(0)][address(0)];

        // model data is always stored for each silo and asset so default values must be replaced
        c.ri = currentConfig.ri;
        c.Tcrit = currentConfig.Tcrit;
        return c;
    }

    /* solhint-disable */

    struct LocalVarsRCur {
        int256 T;
        int256 u;
        int256 DP;
        int256 rp;
        int256 rlin;
        int256 ri;
        bool overflow;
    }

    /// @inheritdoc IInterestRateModel
    function calculateCurrentInterestRate(
        Config memory _c,
        uint256 _totalDeposits,
        uint256 _totalBorrowAmount,
        uint256 _interestRateTimestamp,
        uint256 _blockTimestamp
    ) public pure virtual override returns (uint256 rcur) {
        if (_interestRateTimestamp > _blockTimestamp) revert InvalidTimestamps();

        // struct for local vars to avoid "Stack too deep"
        LocalVarsRCur memory _l = LocalVarsRCur(0,0,0,0,0,0,false);

        (,,,_l.overflow) = calculateCompoundInterestRateWithOverflowDetection(
            _c,
            _totalDeposits,
            _totalBorrowAmount,
            _interestRateTimestamp,
            _blockTimestamp
        );

        if (_l.overflow) {
            return 0;
        }

        // There can't be an underflow in the subtraction because of the previous check
        unchecked {
            // T := t1 - t0 # length of time period in seconds
            _l.T = (_blockTimestamp - _interestRateTimestamp).toInt256();
        }

        _l.u = EasyMathV2.calculateUtilization(DP, _totalDeposits, _totalBorrowAmount).toInt256();
        _l.DP = int256(DP);

        if (_l.u > _c.ucrit) {
            // rp := kcrit *(1 + Tcrit + beta *T)*( u0 - ucrit )
            _l.rp = _c.kcrit * (_l.DP + _c.Tcrit + _c.beta * _l.T) / _l.DP * (_l.u - _c.ucrit) / _l.DP;
        } else {
            // rp := min (0, klow * (u0 - ulow ))
            _l.rp = _min(0, _c.klow * (_l.u - _c.ulow) / _l.DP);
        }

        // rlin := klin * u0 # lower bound between t0 and t1
        _l.rlin = _c.klin * _l.u / _l.DP;
        // ri := max(ri , rlin )
        _l.ri = _max(_c.ri, _l.rlin);
        // ri := max(ri + ki * (u0 - uopt ) * T, rlin )
        _l.ri = _max(_l.ri + _c.ki * (_l.u - _c.uopt) * _l.T / _l.DP, _l.rlin);
        // rcur := max (ri + rp , rlin ) # current per second interest rate
        rcur = (_max(_l.ri + _l.rp, _l.rlin)).toUint256();
        rcur *= 365 days;
    }

    struct LocalVarsRComp {
        int256 T;
        int256 slopei;
        int256 rp;
        int256 slope;
        int256 r0;
        int256 rlin;
        int256 r1;
        int256 x;
        int256 rlin1;
        int256 u;
    }

    function interestRateModelPing() external pure virtual override returns (bytes4) {
        return this.interestRateModelPing.selector;
    }

    /// @inheritdoc IInterestRateModel
    function calculateCompoundInterestRate(
        Config memory _c,
        uint256 _totalDeposits,
        uint256 _totalBorrowAmount,
        uint256 _interestRateTimestamp,
        uint256 _blockTimestamp
    ) public pure virtual override returns (
        uint256 rcomp,
        int256 ri,
        int256 Tcrit
    ) {
        (rcomp, ri, Tcrit,) = calculateCompoundInterestRateWithOverflowDetection(
            _c,
            _totalDeposits,
            _totalBorrowAmount,
            _interestRateTimestamp,
            _blockTimestamp
        );
    }

    /// @inheritdoc IInterestRateModel
    function calculateCompoundInterestRateWithOverflowDetection(
        Config memory _c,
        uint256 _totalDeposits,
        uint256 _totalBorrowAmount,
        uint256 _interestRateTimestamp,
        uint256 _blockTimestamp
    ) public pure virtual override returns (
        uint256 rcomp,
        int256 ri,
        int256 Tcrit,
        bool overflow
    ) {
        ri = _c.ri;
        Tcrit = _c.Tcrit;

        // struct for local vars to avoid "Stack too deep"
        LocalVarsRComp memory _l = LocalVarsRComp(0,0,0,0,0,0,0,0,0,0);

        if (_interestRateTimestamp > _blockTimestamp) revert InvalidTimestamps();

        // There can't be an underflow in the subtraction because of the previous check
    unchecked {
        // length of time period in seconds
        _l.T = (_blockTimestamp - _interestRateTimestamp).toInt256();
    }

        int256 _DP = int256(DP);

        _l.u = EasyMathV2.calculateUtilization(DP, _totalDeposits, _totalBorrowAmount).toInt256();

        // slopei := ki * (u0 - uopt )
        _l.slopei = _c.ki * (_l.u - _c.uopt) / _DP;

        if (_l.u > _c.ucrit) {
            // rp := kcrit * (1 + Tcrit) * (u0 - ucrit )
            _l.rp = _c.kcrit * (_DP + Tcrit) / _DP * (_l.u - _c.ucrit) / _DP;
            // slope := slopei + kcrit * beta * (u0 - ucrit )
            _l.slope = _l.slopei + _c.kcrit * _c.beta / _DP * (_l.u - _c.ucrit) / _DP;
            // Tcrit := Tcrit + beta * T
            Tcrit = Tcrit + _c.beta * _l.T;
        } else {
            // rp := min (0, klow * (u0 - ulow ))
            _l.rp = _min(0, _c.klow * (_l.u - _c.ulow) / _DP);
            // slope := slopei
            _l.slope = _l.slopei;
            // Tcrit := max (0, Tcrit - beta * T)
            Tcrit = _max(0, Tcrit - _c.beta * _l.T);
        }

        // rlin := klin * u0 # lower bound between t0 and t1
        _l.rlin = _c.klin * _l.u / _DP;
        // ri := max(ri , rlin )
        ri = _max(ri , _l.rlin);
        // r0 := ri + rp # interest rate at t0 ignoring lower bound
        _l.r0 = ri + _l.rp;
        // r1 := r0 + slope *T # what interest rate would be at t1 ignoring lower bound
        _l.r1 = _l.r0 + _l.slope * _l.T;

        // Calculating the compound interest

        if (_l.r0 >= _l.rlin && _l.r1 >= _l.rlin) {
            // lower bound isn’t activated
            // rcomp := exp (( r0 + r1) * T / 2) - 1
            _l.x = (_l.r0 + _l.r1) * _l.T / 2;
        } else if (_l.r0 < _l.rlin && _l.r1 < _l.rlin) {
            // lower bound is active during the whole time
            // rcomp := exp( rlin * T) - 1
            _l.x = _l.rlin * _l.T;
        } else if (_l.r0 >= _l.rlin && _l.r1 < _l.rlin) {
            // lower bound is active after some time
            // rcomp := exp( rlin *T - (r0 - rlin )^2/ slope /2) - 1
            _l.x = _l.rlin * _l.T - (_l.r0 - _l.rlin)**2 / _l.slope / 2;
        } else {
            // lower bound is active before some time
            // rcomp := exp( rlin *T + (r1 - rlin )^2/ slope /2) - 1
            _l.x = _l.rlin * _l.T + (_l.r1 - _l.rlin)**2 / _l.slope / 2;
        }

        // ri := max(ri + slopei * T, rlin )
        ri = _max(ri + _l.slopei * _l.T, _l.rlin);

        // Checking for the overflow below. In case of the overflow, ri and Tcrit will be set back to zeros. Rcomp is
        // calculated to not make an overflow in totalBorrowedAmount, totalDeposits.
        (rcomp, overflow) = _calculateRComp(_totalDeposits, _totalBorrowAmount, _l.x);

        if (overflow) {
            ri = 0;
            Tcrit = 0;
        }
    }

    /// @dev set config for silo and asset
    function _setConfig(address _silo, address _asset, Config memory _config) internal virtual {
        int256 _DP = int256(DP);

        if (_config.uopt <= 0 || _config.uopt >= _DP) revert InvalidUopt();
        if (_config.ucrit <= _config.uopt || _config.ucrit >= _DP) revert InvalidUcrit();
        if (_config.ulow <= 0 || _config.ulow >= _config.uopt) revert InvalidUlow();
        if (_config.ki < 0) revert InvalidKi();
        if (_config.kcrit < 0) revert InvalidKcrit();
        if (_config.klow < 0) revert InvalidKlow();
        if (_config.klin < 0) revert InvalidKlin();
        if (_config.beta < 0) revert InvalidBeta();
        if (_config.ri < 0) revert InvalidRi();
        if (_config.Tcrit < 0) revert InvalidTcrit();

        config[_silo][_asset] = _config;
        emit ConfigUpdate(_silo, _asset, _config);
    }

    /* solhint-enable */

    /// @dev checks for the overflow in rcomp calculations, accruedInterest, totalDeposits and totalBorrowedAmount.
    /// In case of the overflow, rcomp is reduced to make totalDeposits and totalBorrowedAmount <= 2**196.
    function _calculateRComp(
        uint256 _totalDeposits,
        uint256 _totalBorrowAmount,
        int256 _x
    ) internal pure virtual returns (uint256 rcomp, bool overflow) {
        int256 rcompSigned;

        if (_x >= X_MAX) {
            rcomp = RCOMP_MAX;
            // overflow, but not return now. It counts as an overflow to reset model parameters,
            // but later on we can get overflow worse.
            overflow = true;
        } else {
            rcompSigned = _x.exp() - int256(DP);
            rcomp = rcompSigned > 0 ? rcompSigned.toUint256() : 0;
        }

        unchecked {
            // maxAmount = max(_totalDeposits, _totalBorrowAmount) to see
            // if any of this variables overflow in result.
            uint256 maxAmount = _totalDeposits > _totalBorrowAmount ? _totalDeposits : _totalBorrowAmount;

            if (maxAmount >= ASSET_DATA_OVERFLOW_LIMIT) {
                return (0, true);
            }

            uint256 rcompMulTBA = rcomp * _totalBorrowAmount;

            if (rcompMulTBA == 0) {
                return (rcomp, overflow);
            }

            if (
                rcompMulTBA / rcomp != _totalBorrowAmount ||
                rcompMulTBA / DP > ASSET_DATA_OVERFLOW_LIMIT - maxAmount
            ) {
                rcomp = (ASSET_DATA_OVERFLOW_LIMIT - maxAmount) * DP / _totalBorrowAmount;

                return (rcomp, true);
            }
        }
    }

    /// @dev Returns the largest of two numbers
    function _max(int256 a, int256 b) internal pure virtual returns (int256) {
        return a > b ? a : b;
    }

    /// @dev Returns the smallest of two numbers
    function _min(int256 a, int256 b) internal pure virtual returns (int256) {
        return a < b ? a : b;
    }
}

// File: contracts/interfaces/IBaseSilo.sol



// SPDX-License-Identifier: BUSL-1.1
pragma solidity 0.8.13;

import "./IShareToken.sol";
import "./IFlashLiquidationReceiver.sol";
import "./ISiloRepository.sol";

interface IBaseSilo {
    enum AssetStatus { Undefined, Active, Removed }

    /// @dev Storage struct that holds all required data for a single token market
    struct AssetStorage {
        /// @dev Token that represents a share in totalDeposits of Silo
        IShareToken collateralToken;
        /// @dev Token that represents a share in collateralOnlyDeposits of Silo
        IShareToken collateralOnlyToken;
        /// @dev Token that represents a share in totalBorrowAmount of Silo
        IShareToken debtToken;
        /// @dev COLLATERAL: Amount of asset token that has been deposited to Silo with interest earned by depositors.
        /// It also includes token amount that has been borrowed.
        uint256 totalDeposits;
        /// @dev COLLATERAL ONLY: Amount of asset token that has been deposited to Silo that can be ONLY used
        /// as collateral. These deposits do NOT earn interest and CANNOT be borrowed.
        uint256 collateralOnlyDeposits;
        /// @dev DEBT: Amount of asset token that has been borrowed with accrued interest.
        uint256 totalBorrowAmount;
    }

    /// @dev Storage struct that holds data related to fees and interest
    struct AssetInterestData {
        /// @dev Total amount of already harvested protocol fees
        uint256 harvestedProtocolFees;
        /// @dev Total amount (ever growing) of asset token that has been earned by the protocol from
        /// generated interest.
        uint256 protocolFees;
        /// @dev Timestamp of the last time `interestRate` has been updated in storage.
        uint64 interestRateTimestamp;
        /// @dev True if asset was removed from the protocol. If so, deposit and borrow functions are disabled
        /// for that asset
        AssetStatus status;
    }

    /// @notice data that InterestModel needs for calculations
    struct UtilizationData {
        uint256 totalDeposits;
        uint256 totalBorrowAmount;
        /// @dev timestamp of last interest accrual
        uint64 interestRateTimestamp;
    }

    /// @dev Shares names and symbols that are generated while asset initialization
    struct AssetSharesMetadata {
        /// @dev Name for the collateral shares token
        string collateralName;
        /// @dev Symbol for the collateral shares token
        string collateralSymbol;
        /// @dev Name for the collateral only (protected collateral) shares token
        string protectedName;
        /// @dev Symbol for the collateral only (protected collateral) shares token
        string protectedSymbol;
        /// @dev Name for the debt shares token
        string debtName;
        /// @dev Symbol for the debt shares token
        string debtSymbol;
    }

    /// @notice Emitted when deposit is made
    /// @param asset asset address that was deposited
    /// @param depositor wallet address that deposited asset
    /// @param amount amount of asset that was deposited
    /// @param collateralOnly type of deposit, true if collateralOnly deposit was used
    event Deposit(address indexed asset, address indexed depositor, uint256 amount, bool collateralOnly);

    /// @notice Emitted when withdraw is made
    /// @param asset asset address that was withdrawn
    /// @param depositor wallet address that deposited asset
    /// @param receiver wallet address that received asset
    /// @param amount amount of asset that was withdrew
    /// @param collateralOnly type of withdraw, true if collateralOnly deposit was used
    event Withdraw(
        address indexed asset,
        address indexed depositor,
        address indexed receiver,
        uint256 amount,
        bool collateralOnly
    );

    /// @notice Emitted on asset borrow
    /// @param asset asset address that was borrowed
    /// @param user wallet address that borrowed asset
    /// @param amount amount of asset that was borrowed
    event Borrow(address indexed asset, address indexed user, uint256 amount);

    /// @notice Emitted on asset repay
    /// @param asset asset address that was repaid
    /// @param user wallet address that repaid asset
    /// @param amount amount of asset that was repaid
    event Repay(address indexed asset, address indexed user, uint256 amount);

    /// @notice Emitted on user liquidation
    /// @param asset asset address that was liquidated
    /// @param user wallet address that was liquidated
    /// @param shareAmountRepaid amount of collateral-share token that was repaid. This is collateral token representing
    /// ownership of underlying deposit.
    /// @param seizedCollateral amount of underlying token that was seized by liquidator
    event Liquidate(address indexed asset, address indexed user, uint256 shareAmountRepaid, uint256 seizedCollateral);

    /// @notice Emitted when the status for an asset is updated
    /// @param asset asset address that was updated
    /// @param status new asset status
    event AssetStatusUpdate(address indexed asset, AssetStatus indexed status);

    /// @return version of the silo contract
    function VERSION() external returns (uint128); // solhint-disable-line func-name-mixedcase

    /// @notice Synchronize current bridge assets with Silo
    /// @dev This function needs to be called on Silo deployment to setup all assets for Silo. It needs to be
    /// called every time a bridged asset is added or removed. When bridge asset is removed, depositing and borrowing
    /// should be disabled during asset sync.
    function syncBridgeAssets() external;

    /// @notice Get Silo Repository contract address
    /// @return Silo Repository contract address
    function siloRepository() external view returns (ISiloRepository);

    /// @notice Get asset storage data
    /// @param _asset asset address
    /// @return AssetStorage struct
    function assetStorage(address _asset) external view returns (AssetStorage memory);

    /// @notice Get asset interest data
    /// @param _asset asset address
    /// @return AssetInterestData struct
    function interestData(address _asset) external view returns (AssetInterestData memory);

    /// @dev helper method for InterestRateModel calculations
    function utilizationData(address _asset) external view returns (UtilizationData memory data);

    /// @notice Calculates solvency of an account
    /// @param _user wallet address for which solvency is calculated
    /// @return true if solvent, false otherwise
    function isSolvent(address _user) external view returns (bool);

    /// @notice Returns all initialized (synced) assets of Silo including current and removed bridge assets
    /// @return assets array of initialized assets of Silo
    function getAssets() external view returns (address[] memory assets);

    /// @notice Returns all initialized (synced) assets of Silo including current and removed bridge assets
    /// with corresponding state
    /// @return assets array of initialized assets of Silo
    /// @return assetsStorage array of assets state corresponding to `assets` array
    function getAssetsWithState() external view returns (address[] memory assets, AssetStorage[] memory assetsStorage);

    /// @notice Check if depositing an asset for given account is possible
    /// @dev Depositing an asset that has been already borrowed (and vice versa) is disallowed
    /// @param _asset asset we want to deposit
    /// @param _depositor depositor address
    /// @return true if asset can be deposited by depositor
    function depositPossible(address _asset, address _depositor) external view returns (bool);

    /// @notice Check if borrowing an asset for given account is possible
    /// @dev Borrowing an asset that has been already deposited (and vice versa) is disallowed
    /// @param _asset asset we want to deposit
    /// @param _borrower borrower address
    /// @return true if asset can be borrowed by borrower
    function borrowPossible(address _asset, address _borrower) external view returns (bool);

    /// @dev Amount of token that is available for borrowing
    /// @param _asset asset to get liquidity for
    /// @return Silo liquidity
    function liquidity(address _asset) external view returns (uint256);
}

// File: contracts/interfaces/IFlashLiquidationReceiver.sol



// SPDX-License-Identifier: MIT
pragma solidity 0.8.13;

/// @dev when performing Silo flash liquidation, FlashReceiver contract will receive all collaterals
interface IFlashLiquidationReceiver {
    /// @dev this method is called when doing Silo flash liquidation
    ///         one can NOT assume, that if _seizedCollateral[i] != 0, then _shareAmountsToRepaid[i] must be 0
    ///         one should assume, that any combination of amounts is possible
    ///         on callback, one must call `Silo.repayFor` because at the end of transaction,
    ///         Silo will check if borrower is solvent.
    /// @param _user user address, that is liquidated
    /// @param _assets array of collateral assets received during user liquidation
    ///         this array contains all assets (collateral borrowed) without any order
    /// @param _receivedCollaterals array of collateral amounts received during user liquidation
    ///         indexes of amounts are related to `_assets`,
    /// @param _shareAmountsToRepaid array of amounts to repay for each asset
    ///         indexes of amounts are related to `_assets`,
    /// @param _flashReceiverData data that are passed from sender that executes liquidation
    function siloLiquidationCallback(
        address _user,
        address[] calldata _assets,
        uint256[] calldata _receivedCollaterals,
        uint256[] calldata _shareAmountsToRepaid,
        bytes memory _flashReceiverData
    ) external;
}

// File: contracts/interfaces/IInterestRateModel.sol



// SPDX-License-Identifier: BUSL-1.1
pragma solidity 0.8.13;

interface IInterestRateModel {
    /* solhint-disable */
    struct Config {
        // uopt ∈ (0, 1) – optimal utilization;
        int256 uopt;
        // ucrit ∈ (uopt, 1) – threshold of large utilization;
        int256 ucrit;
        // ulow ∈ (0, uopt) – threshold of low utilization
        int256 ulow;
        // ki > 0 – integrator gain
        int256 ki;
        // kcrit > 0 – proportional gain for large utilization
        int256 kcrit;
        // klow ≥ 0 – proportional gain for low utilization
        int256 klow;
        // klin ≥ 0 – coefficient of the lower linear bound
        int256 klin;
        // beta ≥ 0 - a scaling factor
        int256 beta;
        // ri ≥ 0 – initial value of the integrator
        int256 ri;
        // Tcrit ≥ 0 - the time during which the utilization exceeds the critical value
        int256 Tcrit;
    }
    /* solhint-enable */

    /// @dev Set dedicated config for given asset in a Silo. Config is per asset per Silo so different assets
    /// in different Silo can have different configs.
    /// It will try to call `_silo.accrueInterest(_asset)` before updating config, but it is not guaranteed,
    /// that this call will be successful, if it fail config will be set anyway.
    /// @param _silo Silo address for which config should be set
    /// @param _asset asset address for which config should be set
    function setConfig(address _silo, address _asset, Config calldata _config) external;

    /// @dev get compound interest rate and update model storage
    /// @param _asset address of an asset in Silo for which interest rate should be calculated
    /// @param _blockTimestamp current block timestamp
    /// @return rcomp compounded interest rate from last update until now (1e18 == 100%)
    function getCompoundInterestRateAndUpdate(
        address _asset,
        uint256 _blockTimestamp
    ) external returns (uint256 rcomp);

    /// @dev Get config for given asset in a Silo. If dedicated config is not set, default one will be returned.
    /// @param _silo Silo address for which config should be set
    /// @param _asset asset address for which config should be set
    /// @return Config struct for asset in Silo
    function getConfig(address _silo, address _asset) external view returns (Config memory);

    /// @dev get compound interest rate
    /// @param _silo address of Silo
    /// @param _asset address of an asset in Silo for which interest rate should be calculated
    /// @param _blockTimestamp current block timestamp
    /// @return rcomp compounded interest rate from last update until now (1e18 == 100%)
    function getCompoundInterestRate(
        address _silo,
        address _asset,
        uint256 _blockTimestamp
    ) external view returns (uint256 rcomp);

    /// @dev get current annual interest rate
    /// @param _silo address of Silo
    /// @param _asset address of an asset in Silo for which interest rate should be calculated
    /// @param _blockTimestamp current block timestamp
    /// @return rcur current annual interest rate (1e18 == 100%)
    function getCurrentInterestRate(
        address _silo,
        address _asset,
        uint256 _blockTimestamp
    ) external view returns (uint256 rcur);

    /// @notice get the flag to detect rcomp restriction (zero current interest) due to overflow
    /// overflow boolean flag to detect rcomp restriction
    function overflowDetected(
        address _silo,
        address _asset,
        uint256 _blockTimestamp
    ) external view returns (bool overflow);

    /// @dev pure function that calculates current annual interest rate
    /// @param _c configuration object, InterestRateModel.Config
    /// @param _totalBorrowAmount current total borrows for asset
    /// @param _totalDeposits current total deposits for asset
    /// @param _interestRateTimestamp timestamp of last interest rate update
    /// @param _blockTimestamp current block timestamp
    /// @return rcur current annual interest rate (1e18 == 100%)
    function calculateCurrentInterestRate(
        Config memory _c,
        uint256 _totalDeposits,
        uint256 _totalBorrowAmount,
        uint256 _interestRateTimestamp,
        uint256 _blockTimestamp
    ) external pure returns (uint256 rcur);

    /// @dev pure function that calculates interest rate based on raw input data
    /// @param _c configuration object, InterestRateModel.Config
    /// @param _totalBorrowAmount current total borrows for asset
    /// @param _totalDeposits current total deposits for asset
    /// @param _interestRateTimestamp timestamp of last interest rate update
    /// @param _blockTimestamp current block timestamp
    /// @return rcomp compounded interest rate from last update until now (1e18 == 100%)
    /// @return ri current integral part of the rate
    /// @return Tcrit time during which the utilization exceeds the critical value
    /// @return overflow boolean flag to detect rcomp restriction
    function calculateCompoundInterestRateWithOverflowDetection(
        Config memory _c,
        uint256 _totalDeposits,
        uint256 _totalBorrowAmount,
        uint256 _interestRateTimestamp,
        uint256 _blockTimestamp
    ) external pure returns (
        uint256 rcomp,
        int256 ri,
        int256 Tcrit, // solhint-disable-line var-name-mixedcase
        bool overflow
    );

    /// @dev pure function that calculates interest rate based on raw input data
    /// @param _c configuration object, InterestRateModel.Config
    /// @param _totalBorrowAmount current total borrows for asset
    /// @param _totalDeposits current total deposits for asset
    /// @param _interestRateTimestamp timestamp of last interest rate update
    /// @param _blockTimestamp current block timestamp
    /// @return rcomp compounded interest rate from last update until now (1e18 == 100%)
    /// @return ri current integral part of the rate
    /// @return Tcrit time during which the utilization exceeds the critical value
    function calculateCompoundInterestRate(
        Config memory _c,
        uint256 _totalDeposits,
        uint256 _totalBorrowAmount,
        uint256 _interestRateTimestamp,
        uint256 _blockTimestamp
    ) external pure returns (
        uint256 rcomp,
        int256 ri,
        int256 Tcrit // solhint-disable-line var-name-mixedcase
    );

    /// @dev returns decimal points used by model
    function DP() external pure returns (uint256); // solhint-disable-line func-name-mixedcase

    /// @dev just a helper method to see if address is a InterestRateModel
    /// @return always true
    function interestRateModelPing() external pure returns (bytes4);
}

// File: contracts/interfaces/INotificationReceiver.sol



// SPDX-License-Identifier: BUSL-1.1
pragma solidity 0.8.13;

/// @title Common interface for Silo Incentive Contract
interface INotificationReceiver {
    /// @dev Informs the contract about token transfer
    /// @param _token address of the token that was transferred
    /// @param _from sender
    /// @param _to receiver
    /// @param _amount amount that was transferred
    function onAfterTransfer(address _token, address _from, address _to, uint256 _amount) external;

    /// @dev Sanity check function
    /// @return always true
    function notificationReceiverPing() external pure returns (bytes4);
}

// File: contracts/interfaces/IPriceProvider.sol



// SPDX-License-Identifier: BUSL-1.1
pragma solidity >=0.7.6 <0.9.0;

/// @title Common interface for Silo Price Providers
interface IPriceProvider {
    /// @notice Returns "Time-Weighted Average Price" for an asset. Calculates TWAP price for quote/asset.
    /// It unifies all tokens decimal to 18, examples:
    /// - if asses == quote it returns 1e18
    /// - if asset is USDC and quote is ETH and ETH costs ~$3300 then it returns ~0.0003e18 WETH per 1 USDC
    /// @param _asset address of an asset for which to read price
    /// @return price of asses with 18 decimals, throws when pool is not ready yet to provide price
    function getPrice(address _asset) external view returns (uint256 price);

    /// @dev Informs if PriceProvider is setup for asset. It does not means PriceProvider can provide price right away.
    /// Some providers implementations need time to "build" buffer for TWAP price,
    /// so price may not be available yet but this method will return true.
    /// @param _asset asset in question
    /// @return TRUE if asset has been setup, otherwise false
    function assetSupported(address _asset) external view returns (bool);

    /// @notice Gets token address in which prices are quoted
    /// @return quoteToken address
    function quoteToken() external view returns (address);

    /// @notice Helper method that allows easily detects, if contract is PriceProvider
    /// @dev this can save us from simple human errors, in case we use invalid address
    /// but this should NOT be treated as security check
    /// @return always true
    function priceProviderPing() external pure returns (bytes4);
}

// File: contracts/interfaces/IPriceProvidersRepository.sol



// SPDX-License-Identifier: BUSL-1.1
pragma solidity >=0.7.6 <0.9.0;

import "./IPriceProvider.sol";

interface IPriceProvidersRepository {
    /// @notice Emitted when price provider is added
    /// @param newPriceProvider new price provider address
    event NewPriceProvider(IPriceProvider indexed newPriceProvider);

    /// @notice Emitted when price provider is removed
    /// @param priceProvider removed price provider address
    event PriceProviderRemoved(IPriceProvider indexed priceProvider);

    /// @notice Emitted when asset is assigned to price provider
    /// @param asset assigned asset   address
    /// @param priceProvider price provider address
    event PriceProviderForAsset(address indexed asset, IPriceProvider indexed priceProvider);

    /// @notice Register new price provider
    /// @param _priceProvider address of price provider
    function addPriceProvider(IPriceProvider _priceProvider) external;

    /// @notice Unregister price provider
    /// @param _priceProvider address of price provider to be removed
    function removePriceProvider(IPriceProvider _priceProvider) external;

    /// @notice Sets price provider for asset
    /// @dev Request for asset price is forwarded to the price provider assigned to that asset
    /// @param _asset address of an asset for which price provider will be used
    /// @param _priceProvider address of price provider
    function setPriceProviderForAsset(address _asset, IPriceProvider _priceProvider) external;

    /// @notice Returns "Time-Weighted Average Price" for an asset
    /// @param _asset address of an asset for which to read price
    /// @return price TWAP price of a token with 18 decimals
    function getPrice(address _asset) external view returns (uint256 price);

    /// @notice Gets price provider assigned to an asset
    /// @param _asset address of an asset for which to get price provider
    /// @return priceProvider address of price provider
    function priceProviders(address _asset) external view returns (IPriceProvider priceProvider);

    /// @notice Gets token address in which prices are quoted
    /// @return quoteToken address
    function quoteToken() external view returns (address);

    /// @notice Gets manager role address
    /// @return manager role address
    function manager() external view returns (address);

    /// @notice Checks if providers are available for an asset
    /// @param _asset asset address to check
    /// @return returns TRUE if price feed is ready, otherwise false
    function providersReadyForAsset(address _asset) external view returns (bool);

    /// @notice Returns true if address is a registered price provider
    /// @param _provider address of price provider to be removed
    /// @return true if address is a registered price provider, otherwise false
    function isPriceProvider(IPriceProvider _provider) external view returns (bool);

    /// @notice Gets number of price providers registered
    /// @return number of price providers registered
    function providersCount() external view returns (uint256);

    /// @notice Gets an array of price providers
    /// @return array of price providers
    function providerList() external view returns (address[] memory);

    /// @notice Sanity check function
    /// @return returns always TRUE
    function priceProvidersRepositoryPing() external pure returns (bytes4);
}

// File: contracts/interfaces/IShareToken.sol



// SPDX-License-Identifier: BUSL-1.1
pragma solidity 0.8.13;

import "@openzeppelin/contracts/token/ERC20/extensions/IERC20Metadata.sol";

import "./INotificationReceiver.sol";

interface IShareToken is IERC20Metadata {
    /// @notice Emitted every time receiver is notified about token transfer
    /// @param notificationReceiver receiver address
    /// @param success false if TX reverted on `notificationReceiver` side, otherwise true
    event NotificationSent(
        INotificationReceiver indexed notificationReceiver,
        bool success
    );

    /// @notice Mint method for Silo to create debt position
    /// @param _account wallet for which to mint token
    /// @param _amount amount of token to be minted
    function mint(address _account, uint256 _amount) external;

    /// @notice Burn method for Silo to close debt position
    /// @param _account wallet for which to burn token
    /// @param _amount amount of token to be burned
    function burn(address _account, uint256 _amount) external;
}

// File: contracts/interfaces/ISilo.sol



// SPDX-License-Identifier: BUSL-1.1
pragma solidity 0.8.13;

import "./IBaseSilo.sol";

interface ISilo is IBaseSilo {
    /// @notice Deposit `_amount` of `_asset` tokens from `msg.sender` to the Silo
    /// @param _asset The address of the token to deposit
    /// @param _amount The amount of the token to deposit
    /// @param _collateralOnly True if depositing collateral only
    /// @return collateralAmount deposited amount
    /// @return collateralShare user collateral shares based on deposited amount
    function deposit(address _asset, uint256 _amount, bool _collateralOnly)
        external
        returns (uint256 collateralAmount, uint256 collateralShare);

    /// @notice Router function to deposit `_amount` of `_asset` tokens to the Silo for the `_depositor`
    /// @param _asset The address of the token to deposit
    /// @param _depositor The address of the recipient of collateral tokens
    /// @param _amount The amount of the token to deposit
    /// @param _collateralOnly True if depositing collateral only
    /// @return collateralAmount deposited amount
    /// @return collateralShare `_depositor` collateral shares based on deposited amount
    function depositFor(address _asset, address _depositor, uint256 _amount, bool _collateralOnly)
        external
        returns (uint256 collateralAmount, uint256 collateralShare);

    /// @notice Withdraw `_amount` of `_asset` tokens from the Silo to `msg.sender`
    /// @param _asset The address of the token to withdraw
    /// @param _amount The amount of the token to withdraw
    /// @param _collateralOnly True if withdrawing collateral only deposit
    /// @return withdrawnAmount withdrawn amount that was transferred to user
    /// @return withdrawnShare burned share based on `withdrawnAmount`
    function withdraw(address _asset, uint256 _amount, bool _collateralOnly)
        external
        returns (uint256 withdrawnAmount, uint256 withdrawnShare);

    /// @notice Router function to withdraw `_amount` of `_asset` tokens from the Silo for the `_depositor`
    /// @param _asset The address of the token to withdraw
    /// @param _depositor The address that originally deposited the collateral tokens being withdrawn,
    /// it should be the one initiating the withdrawal through the router
    /// @param _receiver The address that will receive the withdrawn tokens
    /// @param _amount The amount of the token to withdraw
    /// @param _collateralOnly True if withdrawing collateral only deposit
    /// @return withdrawnAmount withdrawn amount that was transferred to `_receiver`
    /// @return withdrawnShare burned share based on `withdrawnAmount`
    function withdrawFor(
        address _asset,
        address _depositor,
        address _receiver,
        uint256 _amount,
        bool _collateralOnly
    ) external returns (uint256 withdrawnAmount, uint256 withdrawnShare);

    /// @notice Borrow `_amount` of `_asset` tokens from the Silo to `msg.sender`
    /// @param _asset The address of the token to borrow
    /// @param _amount The amount of the token to borrow
    /// @return debtAmount borrowed amount
    /// @return debtShare user debt share based on borrowed amount
    function borrow(address _asset, uint256 _amount) external returns (uint256 debtAmount, uint256 debtShare);

    /// @notice Router function to borrow `_amount` of `_asset` tokens from the Silo for the `_receiver`
    /// @param _asset The address of the token to borrow
    /// @param _borrower The address that will take the loan,
    /// it should be the one initiating the borrowing through the router
    /// @param _receiver The address of the asset receiver
    /// @param _amount The amount of the token to borrow
    /// @return debtAmount borrowed amount
    /// @return debtShare `_receiver` debt share based on borrowed amount
    function borrowFor(address _asset, address _borrower, address _receiver, uint256 _amount)
        external
        returns (uint256 debtAmount, uint256 debtShare);

    /// @notice Repay `_amount` of `_asset` tokens from `msg.sender` to the Silo
    /// @param _asset The address of the token to repay
    /// @param _amount amount of asset to repay, includes interests
    /// @return repaidAmount amount repaid
    /// @return burnedShare burned debt share
    function repay(address _asset, uint256 _amount) external returns (uint256 repaidAmount, uint256 burnedShare);

    /// @notice Allows to repay in behalf of borrower to execute liquidation
    /// @param _asset The address of the token to repay
    /// @param _borrower The address of the user to have debt tokens burned
    /// @param _amount amount of asset to repay, includes interests
    /// @return repaidAmount amount repaid
    /// @return burnedShare burned debt share
    function repayFor(address _asset, address _borrower, uint256 _amount)
        external
        returns (uint256 repaidAmount, uint256 burnedShare);

    /// @dev harvest protocol fees from an array of assets
    /// @return harvestedAmounts amount harvested during tx execution for each of silo asset
    function harvestProtocolFees() external returns (uint256[] memory harvestedAmounts);

    /// @notice Function to update interests for `_asset` token since the last saved state
    /// @param _asset The address of the token to be updated
    /// @return interest accrued interest
    function accrueInterest(address _asset) external returns (uint256 interest);

    /// @notice this methods does not requires to have tokens in order to liquidate user
    /// @dev during liquidation process, msg.sender will be notified once all collateral will be send to him
    /// msg.sender needs to be `IFlashLiquidationReceiver`
    /// @param _users array of users to liquidate
    /// @param _flashReceiverData this data will be forward to msg.sender on notification
    /// @return assets array of all processed assets (collateral + debt, including removed)
    /// @return receivedCollaterals receivedCollaterals[userId][assetId] => amount
    /// amounts of collaterals send to `_flashReceiver`
    /// @return shareAmountsToRepaid shareAmountsToRepaid[userId][assetId] => amount
    /// required amounts of debt to be repaid
    function flashLiquidate(address[] memory _users, bytes memory _flashReceiverData)
        external
        returns (
            address[] memory assets,
            uint256[][] memory receivedCollaterals,
            uint256[][] memory shareAmountsToRepaid
        );
}

// File: contracts/interfaces/ISiloFactory.sol



// SPDX-License-Identifier: BUSL-1.1
pragma solidity 0.8.13;

interface ISiloFactory {
    /// @notice Emitted when Silo is deployed
    /// @param silo address of deployed Silo
    /// @param asset address of asset for which Silo was deployed
    /// @param version version of silo implementation
    event NewSiloCreated(address indexed silo, address indexed asset, uint128 version);

    /// @notice Must be called by repository on constructor
    /// @param _siloRepository the SiloRepository to set
    function initRepository(address _siloRepository) external;

    /// @notice Deploys Silo
    /// @param _siloAsset unique asset for which Silo is deployed
    /// @param _version version of silo implementation
    /// @param _data (optional) data that may be needed during silo creation
    /// @return silo deployed Silo address
    function createSilo(address _siloAsset, uint128 _version, bytes memory _data) external returns (address silo);

    /// @dev just a helper method to see if address is a factory
    function siloFactoryPing() external pure returns (bytes4);
}

// File: contracts/interfaces/ISiloRepository.sol



// SPDX-License-Identifier: BUSL-1.1
pragma solidity 0.8.13;

import "./ISiloFactory.sol";
import "./ITokensFactory.sol";
import "./IPriceProvidersRepository.sol";
import "./INotificationReceiver.sol";
import "./IInterestRateModel.sol";

interface ISiloRepository {
    /// @dev protocol fees in precision points (Solvency._PRECISION_DECIMALS), we do allow for fee == 0
    struct Fees {
        /// @dev One time protocol fee for opening a borrow position in precision points (Solvency._PRECISION_DECIMALS)
        uint64 entryFee;
        /// @dev Protocol revenue share in interest paid in precision points (Solvency._PRECISION_DECIMALS)
        uint64 protocolShareFee;
        /// @dev Protocol share in liquidation profit in precision points (Solvency._PRECISION_DECIMALS).
        /// It's calculated from total collateral amount to be transferred to liquidator.
        uint64 protocolLiquidationFee;
    }

    struct SiloVersion {
        /// @dev Default version of Silo. If set to 0, it means it is not set. By default it is set to 1
        uint128 byDefault;

        /// @dev Latest added version of Silo. If set to 0, it means it is not set. By default it is set to 1
        uint128 latest;
    }

    /// @dev AssetConfig struct represents configurable parameters for each Silo
    struct AssetConfig {
        /// @dev Loan-to-Value ratio represents the maximum borrowing power of a specific collateral.
        ///      For example, if the collateral asset has an LTV of 75%, the user can borrow up to 0.75 worth
        ///      of quote token in the principal currency for every quote token worth of collateral.
        ///      value uses 18 decimals eg. 100% == 1e18
        ///      max valid value is 1e18 so it needs storage of 60 bits
        uint64 maxLoanToValue;

        /// @dev Liquidation Threshold represents the threshold at which a borrow position will be considered
        ///      undercollateralized and subject to liquidation for each collateral. For example,
        ///      if a collateral has a liquidation threshold of 80%, it means that the loan will be
        ///      liquidated when the borrowAmount value is worth 80% of the collateral value.
        ///      value uses 18 decimals eg. 100% == 1e18
        uint64 liquidationThreshold;

        /// @dev interest rate model address
        IInterestRateModel interestRateModel;
    }

    event NewDefaultMaximumLTV(uint64 defaultMaximumLTV);

    event NewDefaultLiquidationThreshold(uint64 defaultLiquidationThreshold);

    /// @notice Emitted on new Silo creation
    /// @param silo deployed Silo address
    /// @param asset unique asset for deployed Silo
    /// @param siloVersion version of deployed Silo
    event NewSilo(address indexed silo, address indexed asset, uint128 siloVersion);

    /// @notice Emitted when new Silo (or existing one) becomes a bridge pool (pool with only bridge tokens).
    /// @param pool address of the bridge pool, It can be zero address when bridge asset is removed and pool no longer
    /// is treated as bridge pool
    event BridgePool(address indexed pool);

    /// @notice Emitted on new bridge asset
    /// @param newBridgeAsset address of added bridge asset
    event BridgeAssetAdded(address indexed newBridgeAsset);

    /// @notice Emitted on removed bridge asset
    /// @param bridgeAssetRemoved address of removed bridge asset
    event BridgeAssetRemoved(address indexed bridgeAssetRemoved);

    /// @notice Emitted when default interest rate model is changed
    /// @param newModel address of new interest rate model
    event InterestRateModel(IInterestRateModel indexed newModel);

    /// @notice Emitted on price provider repository address update
    /// @param newProvider address of new oracle repository
    event PriceProvidersRepositoryUpdate(
        IPriceProvidersRepository indexed newProvider
    );

    /// @notice Emitted on token factory address update
    /// @param newTokensFactory address of new token factory
    event TokensFactoryUpdate(address indexed newTokensFactory);

    /// @notice Emitted on router address update
    /// @param newRouter address of new router
    event RouterUpdate(address indexed newRouter);

    /// @notice Emitted on INotificationReceiver address update
    /// @param newIncentiveContract address of new INotificationReceiver
    event NotificationReceiverUpdate(INotificationReceiver indexed newIncentiveContract);

    /// @notice Emitted when new Silo version is registered
    /// @param factory factory address that deploys registered Silo version
    /// @param siloLatestVersion Silo version of registered Silo
    /// @param siloDefaultVersion current default Silo version
    event RegisterSiloVersion(address indexed factory, uint128 siloLatestVersion, uint128 siloDefaultVersion);

    /// @notice Emitted when Silo version is unregistered
    /// @param factory factory address that deploys unregistered Silo version
    /// @param siloVersion version that was unregistered
    event UnregisterSiloVersion(address indexed factory, uint128 siloVersion);

    /// @notice Emitted when default Silo version is updated
    /// @param newDefaultVersion new default version
    event SiloDefaultVersion(uint128 newDefaultVersion);

    /// @notice Emitted when default fee is updated
    /// @param newEntryFee new entry fee
    /// @param newProtocolShareFee new protocol share fee
    /// @param newProtocolLiquidationFee new protocol liquidation fee
    event FeeUpdate(
        uint64 newEntryFee,
        uint64 newProtocolShareFee,
        uint64 newProtocolLiquidationFee
    );

    /// @notice Emitted when asset config is updated for a silo
    /// @param silo silo for which asset config is being set
    /// @param asset asset for which asset config is being set
    /// @param assetConfig new asset config
    event AssetConfigUpdate(address indexed silo, address indexed asset, AssetConfig assetConfig);

    /// @notice Emitted when silo (silo factory) version is set for asset
    /// @param asset asset for which asset config is being set
    /// @param version Silo version
    event VersionForAsset(address indexed asset, uint128 version);

    /// @param _siloAsset silo asset
    /// @return version of Silo that is assigned for provided asset, if not assigned it returns zero (default)
    function getVersionForAsset(address _siloAsset) external returns (uint128);

    /// @notice setter for `getVersionForAsset` mapping
    /// @param _siloAsset silo asset
    /// @param _version version of Silo that will be assigned for `_siloAsset`, zero (default) is acceptable
    function setVersionForAsset(address _siloAsset, uint128 _version) external;

    /// @notice use this method only when off-chain verification is OFF
    /// @dev Silo does NOT support rebase and deflationary tokens
    /// @param _siloAsset silo asset
    /// @param _siloData (optional) data that may be needed during silo creation
    /// @return createdSilo address of created silo
    function newSilo(address _siloAsset, bytes memory _siloData) external returns (address createdSilo);

    /// @notice use this method to deploy new version of Silo for an asset that already has Silo deployed.
    /// Only owner (DAO) can replace.
    /// @dev Silo does NOT support rebase and deflationary tokens
    /// @param _siloAsset silo asset
    /// @param _siloVersion version of silo implementation. Use 0 for default version which is fine
    /// for 99% of cases.
    /// @param _siloData (optional) data that may be needed during silo creation
    /// @return createdSilo address of created silo
    function replaceSilo(
        address _siloAsset,
        uint128 _siloVersion,
        bytes memory _siloData
    ) external returns (address createdSilo);

    /// @notice Set factory contract for debt and collateral tokens for each Silo asset
    /// @dev Callable only by owner
    /// @param _tokensFactory address of TokensFactory contract that deploys debt and collateral tokens
    function setTokensFactory(address _tokensFactory) external;

    /// @notice Set default fees
    /// @dev Callable only by owner
    /// @param _fees:
    /// - _entryFee one time protocol fee for opening a borrow position in precision points
    /// (Solvency._PRECISION_DECIMALS)
    /// - _protocolShareFee protocol revenue share in interest paid in precision points
    /// (Solvency._PRECISION_DECIMALS)
    /// - _protocolLiquidationFee protocol share in liquidation profit in precision points
    /// (Solvency._PRECISION_DECIMALS). It's calculated from total collateral amount to be transferred
    /// to liquidator.
    function setFees(Fees calldata _fees) external;

    /// @notice Set configuration for given asset in given Silo
    /// @dev Callable only by owner
    /// @param _silo Silo address for which config applies
    /// @param _asset asset address for which config applies
    /// @param _assetConfig:
    ///    - _maxLoanToValue maximum Loan-to-Value, for details see `Repository.AssetConfig.maxLoanToValue`
    ///    - _liquidationThreshold liquidation threshold, for details see `Repository.AssetConfig.maxLoanToValue`
    ///    - _interestRateModel interest rate model address, for details see `Repository.AssetConfig.interestRateModel`
    function setAssetConfig(
        address _silo,
        address _asset,
        AssetConfig calldata _assetConfig
    ) external;

    /// @notice Set default interest rate model
    /// @dev Callable only by owner
    /// @param _defaultInterestRateModel default interest rate model
    function setDefaultInterestRateModel(IInterestRateModel _defaultInterestRateModel) external;

    /// @notice Set default maximum LTV
    /// @dev Callable only by owner
    /// @param _defaultMaxLTV default maximum LTV in precision points (Solvency._PRECISION_DECIMALS)
    function setDefaultMaximumLTV(uint64 _defaultMaxLTV) external;

    /// @notice Set default liquidation threshold
    /// @dev Callable only by owner
    /// @param _defaultLiquidationThreshold default liquidation threshold in precision points
    /// (Solvency._PRECISION_DECIMALS)
    function setDefaultLiquidationThreshold(uint64 _defaultLiquidationThreshold) external;

    /// @notice Set price provider repository
    /// @dev Callable only by owner
    /// @param _repository price provider repository address
    function setPriceProvidersRepository(IPriceProvidersRepository _repository) external;

    /// @notice Set router contract
    /// @dev Callable only by owner
    /// @param _router router address
    function setRouter(address _router) external;

    /// @notice Set NotificationReceiver contract
    /// @dev Callable only by owner
    /// @param _silo silo address for which to set `_notificationReceiver`
    /// @param _notificationReceiver NotificationReceiver address
    function setNotificationReceiver(address _silo, INotificationReceiver _notificationReceiver) external;

    /// @notice Adds new bridge asset
    /// @dev New bridge asset must be unique. Duplicates in bridge assets are not allowed. It's possible to add
    /// bridge asset that has been removed in the past. Note that all Silos must be synced manually. Callable
    /// only by owner.
    /// @param _newBridgeAsset bridge asset address
    function addBridgeAsset(address _newBridgeAsset) external;

    /// @notice Removes bridge asset
    /// @dev Note that all Silos must be synced manually. Callable only by owner.
    /// @param _bridgeAssetToRemove bridge asset address to be removed
    function removeBridgeAsset(address _bridgeAssetToRemove) external;

    /// @notice Registers new Silo version
    /// @dev User can choose which Silo version he wants to deploy. It's possible to have multiple versions of Silo.
    /// Callable only by owner.
    /// @param _factory factory contract that deploys new version of Silo
    /// @param _isDefault true if this version should be used as default
    function registerSiloVersion(ISiloFactory _factory, bool _isDefault) external;

    /// @notice Unregisters Silo version
    /// @dev Callable only by owner.
    /// @param _siloVersion Silo version to be unregistered
    function unregisterSiloVersion(uint128 _siloVersion) external;

    /// @notice Sets default Silo version
    /// @dev Callable only by owner.
    /// @param _defaultVersion Silo version to be set as default
    function setDefaultSiloVersion(uint128 _defaultVersion) external;

    /// @notice Check if contract address is a Silo deployment
    /// @param _silo address of expected Silo
    /// @return true if address is Silo deployment, otherwise false
    function isSilo(address _silo) external view returns (bool);

    /// @notice Get Silo address of asset
    /// @param _asset address of asset
    /// @return address of corresponding Silo deployment
    function getSilo(address _asset) external view returns (address);

    /// @notice Get Silo Factory for given version
    /// @param _siloVersion version of Silo implementation
    /// @return ISiloFactory contract that deploys Silos of given version
    function siloFactory(uint256 _siloVersion) external view returns (ISiloFactory);

    /// @notice Get debt and collateral Token Factory
    /// @return ITokensFactory contract that deploys debt and collateral tokens
    function tokensFactory() external view returns (ITokensFactory);

    /// @notice Get Router contract
    /// @return address of router contract
    function router() external view returns (address);

    /// @notice Get current bridge assets
    /// @dev Keep in mind that not all Silos may be synced with current bridge assets so it's possible that some
    /// assets in that list are not part of given Silo.
    /// @return address array of bridge assets
    function getBridgeAssets() external view returns (address[] memory);

    /// @notice Get removed bridge assets
    /// @dev Keep in mind that not all Silos may be synced with bridge assets so it's possible that some
    /// assets in that list are still part of given Silo.
    /// @return address array of bridge assets
    function getRemovedBridgeAssets() external view returns (address[] memory);

    /// @notice Get maximum LTV for asset in given Silo
    /// @dev If dedicated config is not set, method returns default config
    /// @param _silo address of Silo
    /// @param _asset address of an asset
    /// @return maximum LTV in precision points (Solvency._PRECISION_DECIMALS)
    function getMaximumLTV(address _silo, address _asset) external view returns (uint256);

    /// @notice Get Interest Rate Model address for asset in given Silo
    /// @dev If dedicated config is not set, method returns default config
    /// @param _silo address of Silo
    /// @param _asset address of an asset
    /// @return address of interest rate model
    function getInterestRateModel(address _silo, address _asset) external view returns (IInterestRateModel);

    /// @notice Get liquidation threshold for asset in given Silo
    /// @dev If dedicated config is not set, method returns default config
    /// @param _silo address of Silo
    /// @param _asset address of an asset
    /// @return liquidation threshold in precision points (Solvency._PRECISION_DECIMALS)
    function getLiquidationThreshold(address _silo, address _asset) external view returns (uint256);

    /// @notice Get incentive contract address. Incentive contracts are responsible for distributing rewards
    /// to debt and/or collateral token holders of given Silo
    /// @param _silo address of Silo
    /// @return incentive contract address
    function getNotificationReceiver(address _silo) external view returns (INotificationReceiver);

    /// @notice Get owner role address of Repository
    /// @return owner role address
    function owner() external view returns (address);

    /// @notice get PriceProvidersRepository contract that manages price providers implementations
    /// @return IPriceProvidersRepository address
    function priceProvidersRepository() external view returns (IPriceProvidersRepository);

    /// @dev Get protocol fee for opening a borrow position
    /// @return fee in precision points (Solvency._PRECISION_DECIMALS == 100%)
    function entryFee() external view returns (uint256);

    /// @dev Get protocol share fee
    /// @return protocol share fee in precision points (Solvency._PRECISION_DECIMALS == 100%)
    function protocolShareFee() external view returns (uint256);

    /// @dev Get protocol liquidation fee
    /// @return protocol liquidation fee in precision points (Solvency._PRECISION_DECIMALS == 100%)
    function protocolLiquidationFee() external view returns (uint256);

    /// @dev Checks all conditions for new silo creation and throws when not possible to create
    /// @param _asset address of asset for which you want to create silo
    /// @param _assetIsABridge bool TRUE when `_asset` is bridge asset, FALSE when it is not
    function ensureCanCreateSiloFor(address _asset, bool _assetIsABridge) external view;

    function siloRepositoryPing() external pure returns (bytes4);
}

// File: contracts/interfaces/ITokensFactory.sol



// SPDX-License-Identifier: BUSL-1.1
pragma solidity 0.8.13;

import "./IShareToken.sol";

interface ITokensFactory {
    /// @notice Emitted when collateral token is deployed
    /// @param token address of deployed collateral token
    event NewShareCollateralTokenCreated(address indexed token);

    /// @notice Emitted when collateral token is deployed
    /// @param token address of deployed debt token
    event NewShareDebtTokenCreated(address indexed token);

    ///@notice Must be called by repository on constructor
    /// @param _siloRepository the SiloRepository to set
    function initRepository(address _siloRepository) external;

    /// @notice Deploys collateral token
    /// @param _name name of the token
    /// @param _symbol symbol of the token
    /// @param _asset underlying asset for which token is deployed
    /// @return address of deployed collateral share token
    function createShareCollateralToken(
        string memory _name,
        string memory _symbol,
        address _asset
    ) external returns (IShareToken);

    /// @notice Deploys debt token
    /// @param _name name of the token
    /// @param _symbol symbol of the token
    /// @param _asset underlying asset for which token is deployed
    /// @return address of deployed debt share token
    function createShareDebtToken(
        string memory _name,
        string memory _symbol,
        address _asset
    )
        external
        returns (IShareToken);

    /// @dev just a helper method to see if address is a factory
    /// @return always true
    function tokensFactoryPing() external pure returns (bytes4);
}

// File: contracts/lib/EasyMathV2.sol



// SPDX-License-Identifier: BUSL-1.1
pragma solidity 0.8.13;

/// @dev EasyMathV2 is optimised version of EasyMath, many places was `unchecked` for lower gas cost.
/// There is also fixed version of `calculateUtilization()` method.
library EasyMathV2 {
    error ZeroAssets();
    error ZeroShares();

    function toShare(uint256 amount, uint256 totalAmount, uint256 totalShares)
        internal
        pure
        returns (uint256 result)
    {
        if (totalShares == 0 || totalAmount == 0) {
            return amount;
        }

        result = amount * totalShares;
        // totalAmount is never 0 based on above check, so we can uncheck
        unchecked { result /= totalAmount; }

        // Prevent rounding error
        if (result == 0 && amount != 0) {
            revert ZeroShares();
        }
    }

    function toShareRoundUp(uint256 amount, uint256 totalAmount, uint256 totalShares)
        internal
        pure
        returns (uint256 result)
    {
        if (totalShares == 0 || totalAmount == 0) {
            return amount;
        }

        uint256 numerator = amount * totalShares;
        // totalAmount is not 0, so it is safe to uncheck
        unchecked { result = numerator / totalAmount; }
        
        // Round up
        if (numerator % totalAmount != 0) {
            unchecked { result += 1; }
        }
    }

    function toAmount(uint256 share, uint256 totalAmount, uint256 totalShares)
        internal
        pure
        returns (uint256 result)
    {
        if (totalShares == 0 || totalAmount == 0) {
            return 0;
        }

        result = share * totalAmount;
        // totalShares are not 0, so we can uncheck
        unchecked { result /= totalShares; }

        // Prevent rounding error
        if (result == 0 && share != 0) {
            revert ZeroAssets();
        }
    }

    function toAmountRoundUp(uint256 share, uint256 totalAmount, uint256 totalShares)
        internal
        pure
        returns (uint256 result)
    {
        if (totalShares == 0 || totalAmount == 0) {
            return 0;
        }

        uint256 numerator = share * totalAmount;
        // totalShares are not 0, based on above check, so we can uncheck
        unchecked { result = numerator / totalShares; }
        
        // Round up
        if (numerator % totalShares != 0) {
            unchecked { result += 1; }
        }
    }

    function toValue(uint256 _assetAmount, uint256 _assetPrice, uint256 _assetDecimals)
        internal
        pure
        returns (uint256 value)
    {
        value = _assetAmount * _assetPrice;
        // power of 10 can not be 0, so we can uncheck
        unchecked { value /= 10 ** _assetDecimals; }
    }

    function sum(uint256[] memory _numbers) internal pure returns (uint256 s) {
        for(uint256 i; i < _numbers.length;) {
            s += _numbers[i];
            unchecked { i++; }
        }
    }

    /// @notice Calculates fraction between borrowed and deposited amount of tokens denominated in percentage
    /// @dev It assumes `_dp` = 100%.
    /// @param _dp decimal points used by model
    /// @param _totalDeposits current total deposits for assets
    /// @param _totalBorrowAmount current total borrows for assets
    /// @return utilization value, capped to 100%
    /// Limiting utilisation ratio by 100% max will allows us to perform better interest rate computations
    /// and should not affect any other part of protocol.
    function calculateUtilization(uint256 _dp, uint256 _totalDeposits, uint256 _totalBorrowAmount)
        internal
        pure
        returns (uint256 utilization)
    {
        if (_totalDeposits == 0 || _totalBorrowAmount == 0) return 0;

        utilization = _totalBorrowAmount * _dp;
        // _totalDeposits is not 0 based on above check, so it is safe to uncheck this division
        unchecked { utilization /= _totalDeposits; }

        // cap at 100%
        if (utilization > _dp) utilization = _dp;
    }
}

// File: contracts/lib/PRBMathCommon.sol



// SPDX-License-Identifier: Unlicense
pragma solidity 0.8.13;

/* solhint-disable */
/// @dev Common mathematical functions used in both PRBMathSD59x18 and PRBMathUD60x18. Note that this shared library
/// does not always assume the signed 59.18-decimal fixed-point or the unsigned 60.18-decimal fixed-point
// representation. When it does not, it is annonated in the function's NatSpec documentation.
/// @author Paul Razvan Berg
library PRBMathCommon {
    /// @dev How many trailing decimals can be represented.
    uint256 internal constant SCALE = 1e18;

    /// @notice Calculates the binary exponent of x using the binary fraction method.
    /// @dev Uses 128.128-bit fixed-point numbers - it is the most efficient way.
    /// @param x The exponent as an unsigned 128.128-bit fixed-point number.
    /// @return result The result as an unsigned 60x18 decimal fixed-point number.
    function exp2(uint256 x) internal pure returns (uint256 result) {
        unchecked {
            // Start from 0.5 in the 128.128-bit fixed-point format. We need to use uint256 because the intermediary
            // may get very close to 2^256, which doesn't fit in int256.
            result = 0x80000000000000000000000000000000;

            // Multiply the result by root(2, 2^-i) when the bit at position i is 1. None of the intermediary results overflows
            // because the initial result is 2^127 and all magic factors are less than 2^129.
            if (x & 0x80000000000000000000000000000000 > 0) result = (result * 0x16A09E667F3BCC908B2FB1366EA957D3E) >> 128;
            if (x & 0x40000000000000000000000000000000 > 0) result = (result * 0x1306FE0A31B7152DE8D5A46305C85EDED) >> 128;
            if (x & 0x20000000000000000000000000000000 > 0) result = (result * 0x1172B83C7D517ADCDF7C8C50EB14A7920) >> 128;
            if (x & 0x10000000000000000000000000000000 > 0) result = (result * 0x10B5586CF9890F6298B92B71842A98364) >> 128;
            if (x & 0x8000000000000000000000000000000 > 0) result = (result * 0x1059B0D31585743AE7C548EB68CA417FE) >> 128;
            if (x & 0x4000000000000000000000000000000 > 0) result = (result * 0x102C9A3E778060EE6F7CACA4F7A29BDE9) >> 128;
            if (x & 0x2000000000000000000000000000000 > 0) result = (result * 0x10163DA9FB33356D84A66AE336DCDFA40) >> 128;
            if (x & 0x1000000000000000000000000000000 > 0) result = (result * 0x100B1AFA5ABCBED6129AB13EC11DC9544) >> 128;
            if (x & 0x800000000000000000000000000000 > 0) result = (result * 0x10058C86DA1C09EA1FF19D294CF2F679C) >> 128;
            if (x & 0x400000000000000000000000000000 > 0) result = (result * 0x1002C605E2E8CEC506D21BFC89A23A011) >> 128;
            if (x & 0x200000000000000000000000000000 > 0) result = (result * 0x100162F3904051FA128BCA9C55C31E5E0) >> 128;
            if (x & 0x100000000000000000000000000000 > 0) result = (result * 0x1000B175EFFDC76BA38E31671CA939726) >> 128;
            if (x & 0x80000000000000000000000000000 > 0) result = (result * 0x100058BA01FB9F96D6CACD4B180917C3E) >> 128;
            if (x & 0x40000000000000000000000000000 > 0) result = (result * 0x10002C5CC37DA9491D0985C348C68E7B4) >> 128;
            if (x & 0x20000000000000000000000000000 > 0) result = (result * 0x1000162E525EE054754457D5995292027) >> 128;
            if (x & 0x10000000000000000000000000000 > 0) result = (result * 0x10000B17255775C040618BF4A4ADE83FD) >> 128;
            if (x & 0x8000000000000000000000000000 > 0) result = (result * 0x1000058B91B5BC9AE2EED81E9B7D4CFAC) >> 128;
            if (x & 0x4000000000000000000000000000 > 0) result = (result * 0x100002C5C89D5EC6CA4D7C8ACC017B7CA) >> 128;
            if (x & 0x2000000000000000000000000000 > 0) result = (result * 0x10000162E43F4F831060E02D839A9D16D) >> 128;
            if (x & 0x1000000000000000000000000000 > 0) result = (result * 0x100000B1721BCFC99D9F890EA06911763) >> 128;
            if (x & 0x800000000000000000000000000 > 0) result = (result * 0x10000058B90CF1E6D97F9CA14DBCC1629) >> 128;
            if (x & 0x400000000000000000000000000 > 0) result = (result * 0x1000002C5C863B73F016468F6BAC5CA2C) >> 128;
            if (x & 0x200000000000000000000000000 > 0) result = (result * 0x100000162E430E5A18F6119E3C02282A6) >> 128;
            if (x & 0x100000000000000000000000000 > 0) result = (result * 0x1000000B1721835514B86E6D96EFD1BFF) >> 128;
            if (x & 0x80000000000000000000000000 > 0) result = (result * 0x100000058B90C0B48C6BE5DF846C5B2F0) >> 128;
            if (x & 0x40000000000000000000000000 > 0) result = (result * 0x10000002C5C8601CC6B9E94213C72737B) >> 128;
            if (x & 0x20000000000000000000000000 > 0) result = (result * 0x1000000162E42FFF037DF38AA2B219F07) >> 128;
            if (x & 0x10000000000000000000000000 > 0) result = (result * 0x10000000B17217FBA9C739AA5819F44FA) >> 128;
            if (x & 0x8000000000000000000000000 > 0) result = (result * 0x1000000058B90BFCDEE5ACD3C1CEDC824) >> 128;
            if (x & 0x4000000000000000000000000 > 0) result = (result * 0x100000002C5C85FE31F35A6A30DA1BE51) >> 128;
            if (x & 0x2000000000000000000000000 > 0) result = (result * 0x10000000162E42FF0999CE3541B9FFFD0) >> 128;
            if (x & 0x1000000000000000000000000 > 0) result = (result * 0x100000000B17217F80F4EF5AADDA45554) >> 128;
            if (x & 0x800000000000000000000000 > 0) result = (result * 0x10000000058B90BFBF8479BD5A81B51AE) >> 128;
            if (x & 0x400000000000000000000000 > 0) result = (result * 0x1000000002C5C85FDF84BD62AE30A74CD) >> 128;
            if (x & 0x200000000000000000000000 > 0) result = (result * 0x100000000162E42FEFB2FED257559BDAA) >> 128;
            if (x & 0x100000000000000000000000 > 0) result = (result * 0x1000000000B17217F7D5A7716BBA4A9AF) >> 128;
            if (x & 0x80000000000000000000000 > 0) result = (result * 0x100000000058B90BFBE9DDBAC5E109CCF) >> 128;
            if (x & 0x40000000000000000000000 > 0) result = (result * 0x10000000002C5C85FDF4B15DE6F17EB0E) >> 128;
            if (x & 0x20000000000000000000000 > 0) result = (result * 0x1000000000162E42FEFA494F1478FDE05) >> 128;
            if (x & 0x10000000000000000000000 > 0) result = (result * 0x10000000000B17217F7D20CF927C8E94D) >> 128;
            if (x & 0x8000000000000000000000 > 0) result = (result * 0x1000000000058B90BFBE8F71CB4E4B33E) >> 128;
            if (x & 0x4000000000000000000000 > 0) result = (result * 0x100000000002C5C85FDF477B662B26946) >> 128;
            if (x & 0x2000000000000000000000 > 0) result = (result * 0x10000000000162E42FEFA3AE53369388D) >> 128;
            if (x & 0x1000000000000000000000 > 0) result = (result * 0x100000000000B17217F7D1D351A389D41) >> 128;
            if (x & 0x800000000000000000000 > 0) result = (result * 0x10000000000058B90BFBE8E8B2D3D4EDF) >> 128;
            if (x & 0x400000000000000000000 > 0) result = (result * 0x1000000000002C5C85FDF4741BEA6E77F) >> 128;
            if (x & 0x200000000000000000000 > 0) result = (result * 0x100000000000162E42FEFA39FE95583C3) >> 128;
            if (x & 0x100000000000000000000 > 0) result = (result * 0x1000000000000B17217F7D1CFB72B45E3) >> 128;
            if (x & 0x80000000000000000000 > 0) result = (result * 0x100000000000058B90BFBE8E7CC35C3F2) >> 128;
            if (x & 0x40000000000000000000 > 0) result = (result * 0x10000000000002C5C85FDF473E242EA39) >> 128;
            if (x & 0x20000000000000000000 > 0) result = (result * 0x1000000000000162E42FEFA39F02B772C) >> 128;
            if (x & 0x10000000000000000000 > 0) result = (result * 0x10000000000000B17217F7D1CF7D83C1A) >> 128;
            if (x & 0x8000000000000000000 > 0) result = (result * 0x1000000000000058B90BFBE8E7BDCBE2E) >> 128;
            if (x & 0x4000000000000000000 > 0) result = (result * 0x100000000000002C5C85FDF473DEA871F) >> 128;
            if (x & 0x2000000000000000000 > 0) result = (result * 0x10000000000000162E42FEFA39EF44D92) >> 128;
            if (x & 0x1000000000000000000 > 0) result = (result * 0x100000000000000B17217F7D1CF79E949) >> 128;
            if (x & 0x800000000000000000 > 0) result = (result * 0x10000000000000058B90BFBE8E7BCE545) >> 128;
            if (x & 0x400000000000000000 > 0) result = (result * 0x1000000000000002C5C85FDF473DE6ECA) >> 128;
            if (x & 0x200000000000000000 > 0) result = (result * 0x100000000000000162E42FEFA39EF366F) >> 128;
            if (x & 0x100000000000000000 > 0) result = (result * 0x1000000000000000B17217F7D1CF79AFA) >> 128;
            if (x & 0x80000000000000000 > 0) result = (result * 0x100000000000000058B90BFBE8E7BCD6E) >> 128;
            if (x & 0x40000000000000000 > 0) result = (result * 0x10000000000000002C5C85FDF473DE6B3) >> 128;
            if (x & 0x20000000000000000 > 0) result = (result * 0x1000000000000000162E42FEFA39EF359) >> 128;
            if (x & 0x10000000000000000 > 0) result = (result * 0x10000000000000000B17217F7D1CF79AC) >> 128;

            // Multiply the result by the integer part 2^n + 1. We have to shift by one bit extra because we have already divided
            // by two when we set the result equal to 0.5 above.
            result = result << ((x >> 128) + 1);

            // Convert the result to the signed 60.18-decimal fixed-point format.
            result = PRBMathCommon.mulDiv(result, 1e18, 2**128);
        }
    }

    /// @notice Calculates floor(x*y÷denominator) with full precision.
    ///
    /// @dev Credit to Remco Bloemen under MIT license https://xn--2-umb.com/21/muldiv.
    ///
    /// Requirements:
    /// - The denominator cannot be zero.
    /// - The result must fit within uint256.
    ///
    /// Caveats:
    /// - This function does not work with fixed-point numbers.
    ///
    /// @param x The multiplicand as an uint256.
    /// @param y The multiplier as an uint256.
    /// @param denominator The divisor as an uint256.
    /// @return result The result as an uint256.
    function mulDiv(
        uint256 x,
        uint256 y,
        uint256 denominator
    ) internal pure returns (uint256 result) {
        // 512-bit multiply [prod1 prod0] = x * y. Compute the product mod 2**256 and mod 2**256 - 1, then use
        // use the Chinese Remainder Theorem to reconstruct the 512 bit result. The result is stored in two 256
        // variables such that product = prod1 * 2**256 + prod0.
        uint256 prod0; // Least significant 256 bits of the product
        uint256 prod1; // Most significant 256 bits of the product
        assembly {
            let mm := mulmod(x, y, not(0))
            prod0 := mul(x, y)
            prod1 := sub(sub(mm, prod0), lt(mm, prod0))
        }

        // Handle non-overflow cases, 256 by 256 division
        if (prod1 == 0) {
            require(denominator > 0);
            assembly {
                result := div(prod0, denominator)
            }
            return result;
        }

        // Make sure the result is less than 2**256. Also prevents denominator == 0.
        require(denominator > prod1);

        ///////////////////////////////////////////////
        // 512 by 256 division.
        ///////////////////////////////////////////////

        // Make division exact by subtracting the remainder from [prod1 prod0].
        uint256 remainder;
        assembly {
            // Compute remainder using mulmod.
            remainder := mulmod(x, y, denominator)

            // Subtract 256 bit number from 512 bit number
            prod1 := sub(prod1, gt(remainder, prod0))
            prod0 := sub(prod0, remainder)
        }

        // Factor powers of two out of denominator and compute largest power of two divisor of denominator. Always >= 1.
        // See https://cs.stackexchange.com/q/138556/92363.
        unchecked {
            // Does not overflow because the denominator cannot be zero at this stage in the function.
            uint256 lpotdod = denominator & (~denominator + 1);
            assembly {
                // Divide denominator by lpotdod.
                denominator := div(denominator, lpotdod)

                // Divide [prod1 prod0] by lpotdod.
                prod0 := div(prod0, lpotdod)

                // Flip lpotdod such that it is 2**256 / lpotdod. If lpotdod is zero, then it becomes one.
                lpotdod := add(div(sub(0, lpotdod), lpotdod), 1)
            }

            // Shift in bits from prod1 into prod0.
            prod0 |= prod1 * lpotdod;

            // Invert denominator mod 2**256. Now that denominator is an odd number, it has an inverse modulo 2**256 such
            // that denominator * inv = 1 mod 2**256. Compute the inverse by starting with a seed that is correct for
            // four bits. That is, denominator * inv = 1 mod 2**4
            uint256 inverse = (3 * denominator) ^ 2;

            // Now use Newton-Raphson iteration to improve the precision. Thanks to Hensel's lifting lemma, this also works
            // in modular arithmetic, doubling the correct bits in each step.
            inverse *= 2 - denominator * inverse; // inverse mod 2**8
            inverse *= 2 - denominator * inverse; // inverse mod 2**16
            inverse *= 2 - denominator * inverse; // inverse mod 2**32
            inverse *= 2 - denominator * inverse; // inverse mod 2**64
            inverse *= 2 - denominator * inverse; // inverse mod 2**128
            inverse *= 2 - denominator * inverse; // inverse mod 2**256

            // Because the division is now exact we can divide by multiplying with the modular inverse of denominator.
            // This will give us the correct result modulo 2**256. Since the precoditions guarantee that the outcome is
            // less than 2**256, this is the final result. We don't need to compute the high bits of the result and prod1
            // is no longer required.
            result = prod0 * inverse;
            return result;
        }
    }
}
/* solhint-enable */

// File: contracts/lib/PRBMathSD59x18.sol



// SPDX-License-Identifier: Unlicense
pragma solidity 0.8.13;

import "./PRBMathCommon.sol";

/* solhint-disable */
/// @title PRBMathSD59x18
/// @author Paul Razvan Berg
/// @notice Smart contract library for advanced fixed-point math. It works with int256 numbers considered to have 18
/// trailing decimals. We call this number representation signed 59.18-decimal fixed-point, since the numbers can have
/// a sign and there can be up to 59 digits in the integer part and up to 18 decimals in the fractional part. The numbers
/// are bound by the minimum and the maximum values permitted by the Solidity type int256.
library PRBMathSD59x18 {
    /// @dev log2(e) as a signed 59.18-decimal fixed-point number.
    int256 internal constant LOG2_E = 1442695040888963407;

    /// @dev Half the SCALE number.
    int256 internal constant HALF_SCALE = 5e17;

    /// @dev The maximum value a signed 59.18-decimal fixed-point number can have.
    int256 internal constant MAX_SD59x18 = 57896044618658097711785492504343953926634992332820282019728792003956564819967;

    /// @dev How many trailing decimals can be represented.
    int256 internal constant SCALE = 1e18;

    /// INTERNAL FUNCTIONS ///


    /// @notice Calculates the natural exponent of x.
    ///
    /// @dev Based on the insight that e^x = 2^(x * log2(e)).
    ///
    /// Requirements:
    /// - All from "log2".
    /// - x must be less than 88722839111672999628.
    ///
    /// @param x The exponent as a signed 59.18-decimal fixed-point number.
    /// @return result The result as a signed 59.18-decimal fixed-point number.
    function exp(int256 x) internal pure returns (int256 result) {
        // Without this check, the value passed to "exp2" would be less than -59794705707972522261.
        if (x < -41446531673892822322) {
            return 0;
        }

        // Without this check, the value passed to "exp2" would be greater than 128e18.
        require(x < 88722839111672999628);

        // Do the fixed-point multiplication inline to save gas.
        unchecked {
            int256 doubleScaleProduct = x * LOG2_E;
            result = exp2((doubleScaleProduct + HALF_SCALE) / SCALE);
        }
    }

    /// @notice Calculates the binary exponent of x using the binary fraction method.
    ///
    /// @dev See https://ethereum.stackexchange.com/q/79903/24693.
    ///
    /// Requirements:
    /// - x must be 128e18 or less.
    /// - The result must fit within MAX_SD59x18.
    ///
    /// Caveats:
    /// - For any x less than -59794705707972522261, the result is zero.
    ///
    /// @param x The exponent as a signed 59.18-decimal fixed-point number.
    /// @return result The result as a signed 59.18-decimal fixed-point number.
    function exp2(int256 x) internal pure returns (int256 result) {
        // This works because 2^-x = 1/2^x.
        if (x < 0) {
            // 2**59.794705707972522262 is the maximum number whose inverse does not equal zero.
            if (x < -59794705707972522261) {
                return 0;
            }

            // Do the fixed-point inversion inline to save gas. The numerator is SCALE * SCALE.
            unchecked { result = 1e36 / exp2(-x); }
            return result;
        } else {
            // 2**128 doesn't fit within the 128.128-bit fixed-point representation.
            require(x < 128e18);

            unchecked {
                // Convert x to the 128.128-bit fixed-point format.
                uint256 x128x128 = (uint256(x) << 128) / uint256(SCALE);

                // Safe to convert the result to int256 directly because the maximum input allowed is 128e18.
                result = int256(PRBMathCommon.exp2(x128x128));
            }
        }
    }
}
/* solhint-enable */

// File: contracts/utils/TwoStepOwnable.sol



// SPDX-License-Identifier: BUSL-1.1
pragma solidity >=0.7.6 <0.9.0;

/// @title TwoStepOwnable
/// @notice Contract that implements the same functionality as popular Ownable contract from openzeppelin library.
/// The only difference is that it adds a possibility to transfer ownership in two steps. Single step ownership
/// transfer is still supported.
/// @dev Two step ownership transfer is meant to be used by humans to avoid human error. Single step ownership
/// transfer is meant to be used by smart contracts to avoid over-complicated two step integration. For that reason,
/// both ways are supported.
abstract contract TwoStepOwnable {
    /// @dev current owner
    address private _owner;
    /// @dev candidate to an owner
    address private _pendingOwner;

    /// @notice Emitted when ownership is transferred on `transferOwnership` and `acceptOwnership`
    /// @param newOwner new owner
    event OwnershipTransferred(address indexed newOwner);
    /// @notice Emitted when ownership transfer is proposed, aka pending owner is set
    /// @param newPendingOwner new proposed/pending owner
    event OwnershipPending(address indexed newPendingOwner);

    /**
     *  error OnlyOwner();
     *  error OnlyPendingOwner();
     *  error OwnerIsZero();
     */

    /**
     * @dev Throws if called by any account other than the owner.
     */
    modifier onlyOwner() {
        if (owner() != msg.sender) revert("OnlyOwner");
        _;
    }

    /**
     * @dev Initializes the contract setting the deployer as the initial owner.
     */
    constructor() {
        _setOwner(msg.sender);
    }

    /**
     * @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 {
        _setOwner(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 {
        if (newOwner == address(0)) revert("OwnerIsZero");
        _setOwner(newOwner);
    }

    /**
     * @dev Transfers pending ownership of the contract to a new account (`newPendingOwner`) and clears any existing
     * pending ownership.
     * Can only be called by the current owner.
     */
    function transferPendingOwnership(address newPendingOwner) public virtual onlyOwner {
        _setPendingOwner(newPendingOwner);
    }

    /**
     * @dev Clears the pending ownership.
     * Can only be called by the current owner.
     */
    function removePendingOwnership() public virtual onlyOwner {
        _setPendingOwner(address(0));
    }

    /**
     * @dev Transfers ownership of the contract to a pending owner
     * Can only be called by the pending owner.
     */
    function acceptOwnership() public virtual {
        if (msg.sender != pendingOwner()) revert("OnlyPendingOwner");
        _setOwner(pendingOwner());
    }

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

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

    /**
     * @dev Sets the new owner and emits the corresponding event.
     */
    function _setOwner(address newOwner) private {
        if (_owner == newOwner) revert("OwnerDidNotChange");

        _owner = newOwner;
        emit OwnershipTransferred(newOwner);

        if (_pendingOwner != address(0)) {
            _setPendingOwner(address(0));
        }
    }

    /**
     * @dev Sets the new pending owner and emits the corresponding event.
     */
    function _setPendingOwner(address newPendingOwner) private {
        if (_pendingOwner == newPendingOwner) revert("PendingOwnerDidNotChange");

        _pendingOwner = newPendingOwner;
        emit OwnershipPending(newPendingOwner);
    }
}