// Contract: AggregatorDataProvider
// Target function: function _harvestAndReport()
 + 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) {
                // Solidity will revert if denominator == 0, unlike the div opcode on its own.
                // The surrounding unchecked block does not change this fact.
                // See https://docs.soliditylang.org/en/latest/control-structures.html#checked-or-unchecked-arithmetic.
                return prod0 / denominator;
            }

            // Make sure the result is less than 2^256. Also prevents denominator == 0.
            require(denominator > prod1, "Math: mulDiv overflow");

            ///////////////////////////////////////////////
            // 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.

            // Does not overflow because the denominator cannot be zero at this stage in the function.
            uint256 twos = denominator & (~denominator + 1);
            assembly {
                // Divide denominator by twos.
                denominator := div(denominator, twos)

                // Divide [prod1 prod0] by twos.
                prod0 := div(prod0, twos)

                // Flip twos such that it is 2^256 / twos. If twos is zero, then it becomes one.
                twos := add(div(sub(0, twos), twos), 1)
            }

            // Shift in bits from prod1 into prod0.
            prod0 |= prod1 * twos;

            // 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;

            // Use the 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 preconditions 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;
        }
    }

    /**
     * @notice Calculates x * y / denominator with full precision, following the selected rounding direction.
     */
    function mulDiv(uint256 x, uint256 y, uint256 denominator, Rounding rounding) internal pure returns (uint256) {
        uint256 result = mulDiv(x, y, denominator);
        if (rounding == Rounding.Up && mulmod(x, y, denominator) > 0) {
            result += 1;
        }
        return result;
    }

    /**
     * @dev Returns the square root of a number. If the number is not a perfect square, the value is rounded down.
     *
     * Inspired by Henry S. Warren, Jr.'s "Hacker's Delight" (Chapter 11).
     */
    function sqrt(uint256 a) internal pure returns (uint256) {
        if (a == 0) {
            return 0;
        }

        // For our first guess, we get the biggest power of 2 which is smaller than the square root of the target.
        //
        // We know that the "msb" (most significant bit) of our target number `a` is a power of 2 such that we have
        // `msb(a) <= a < 2*msb(a)`. This value can be written `msb(a)=2**k` with `k=log2(a)`.
        //
        // This can be rewritten `2**log2(a) <= a < 2**(log2(a) + 1)`
        // → `sqrt(2**k) <= sqrt(a) < sqrt(2**(k+1))`
        // → `2**(k/2) <= sqrt(a) < 2**((k+1)/2) <= 2**(k/2 + 1)`
        //
        // Consequently, `2**(log2(a) / 2)` is a good first approximation of `sqrt(a)` with at least 1 correct bit.
        uint256 result = 1 << (log2(a) >> 1);

        // At this point `result` is an estimation with one bit of precision. We know the true value is a uint128,
        // since it is the square root of a uint256. Newton's method converges quadratically (precision doubles at
        // every iteration). We thus need at most 7 iteration to turn our partial result with one bit of precision
        // into the expected uint128 result.
        unchecked {
            result = (result + a / result) >> 1;
            result = (result + a / result) >> 1;
            result = (result + a / result) >> 1;
            result = (result + a / result) >> 1;
            result = (result + a / result) >> 1;
            result = (result + a / result) >> 1;
            result = (result + a / result) >> 1;
            return min(result, a / result);
        }
    }

    /**
     * @notice Calculates sqrt(a), following the selected rounding direction.
     */
    function sqrt(uint256 a, Rounding rounding) internal pure returns (uint256) {
        unchecked {
            uint256 result = sqrt(a);
            return result + (rounding == Rounding.Up && result * result < a ? 1 : 0);
        }
    }

    /**
     * @dev Return the log in base 2, rounded down, of a positive value.
     * Returns 0 if given 0.
     */
    function log2(uint256 value) internal pure returns (uint256) {
        uint256 result = 0;
        unchecked {
            if (value >> 128 > 0) {
                value >>= 128;
                result += 128;
            }
            if (value >> 64 > 0) {
                value >>= 64;
                result += 64;
            }
            if (value >> 32 > 0) {
                value >>= 32;
                result += 32;
            }
            if (value >> 16 > 0) {
                value >>= 16;
                result += 16;
            }
            if (value >> 8 > 0) {
                value >>= 8;
                result += 8;
            }
            if (value >> 4 > 0) {
                value >>= 4;
                result += 4;
            }
            if (value >> 2 > 0) {
                value >>= 2;
                result += 2;
            }
            if (value >> 1 > 0) {
                result += 1;
            }
        }
        return result;
    }

    /**
     * @dev Return the log in base 2, following the selected rounding direction, of a positive value.
     * Returns 0 if given 0.
     */
    function log2(uint256 value, Rounding rounding) internal pure returns (uint256) {
        unchecked {
            uint256 result = log2(value);
            return result + (rounding == Rounding.Up && 1 << result < value ? 1 : 0);
        }
    }

    /**
     * @dev Return the log in base 10, rounded down, of a positive value.
     * Returns 0 if given 0.
     */
    function log10(uint256 value) internal pure returns (uint256) {
        uint256 result = 0;
        unchecked {
            if (value >= 10 ** 64) {
                value /= 10 ** 64;
                result += 64;
            }
            if (value >= 10 ** 32) {
                value /= 10 ** 32;
                result += 32;
            }
            if (value >= 10 ** 16) {
                value /= 10 ** 16;
                result += 16;
            }
            if (value >= 10 ** 8) {
                value /= 10 ** 8;
                result += 8;
            }
            if (value >= 10 ** 4) {
                value /= 10 ** 4;
                result += 4;
            }
            if (value >= 10 ** 2) {
                value /= 10 ** 2;
                result += 2;
            }
            if (value >= 10 ** 1) {
                result += 1;
            }
        }
        return result;
    }

    /**
     * @dev Return the log in base 10, following the selected rounding direction, of a positive value.
     * Returns 0 if given 0.
     */
    function log10(uint256 value, Rounding rounding) internal pure returns (uint256) {
        unchecked {
            uint256 result = log10(value);
            return result + (rounding == Rounding.Up && 10 ** result < value ? 1 : 0);
        }
    }

    /**
     * @dev Return the log in base 256, rounded down, of a positive value.
     * Returns 0 if given 0.
     *
     * Adding one to the result gives the number of pairs of hex symbols needed to represent `value` as a hex string.
     */
    function log256(uint256 value) internal pure returns (uint256) {
        uint256 result = 0;
        unchecked {
            if (value >> 128 > 0) {
                value >>= 128;
                result += 16;
            }
            if (value >> 64 > 0) {
                value >>= 64;
                result += 8;
            }
            if (value >> 32 > 0) {
                value >>= 32;
                result += 4;
            }
            if (value >> 16 > 0) {
                value >>= 16;
                result += 2;
            }
            if (value >> 8 > 0) {
                result += 1;
            }
        }
        return result;
    }

    /**
     * @dev Return the log in base 256, following the selected rounding direction, of a positive value.
     * Returns 0 if given 0.
     */
    function log256(uint256 value, Rounding rounding) internal pure returns (uint256) {
        unchecked {
            uint256 result = log256(value);
            return result + (rounding == Rounding.Up && 1 << (result << 3) < value ? 1 : 0);
        }
    }
}

struct VaultAccount {
    uint128 amount; // Total amount, analogous to market cap
    uint128 shares; // Total shares, analogous to shares outstanding
}

interface IFraxLendV3 {
    struct CurrentRateInfo {
        uint32 lastBlock;
        uint32 feeToProtocolRate; // Fee amount 1e5 precision
        uint64 lastTimestamp;
        uint64 ratePerSec;
        uint64 fullUtilizationRate;
    }

    function isInterestPaused() external view returns (bool);

    function toAssetAmount(
        uint256 _shares,
        bool _roundUp,
        bool _previewInterest
    ) external view returns (uint256);

    function toAssetShares(
        uint256 _amount,
        bool _roundUp,
        bool _previewInterest
    ) external view returns (uint256);

    function getConstants()
        external
        pure
        returns (
            uint256 _LTV_PRECISION,
            uint256 _LIQ_PRECISION,
            uint256 _UTIL_PREC,
            uint256 _FEE_PRECISION,
            uint256 _EXCHANGE_PRECISION,
            uint256 _DEVIATION_PRECISION,
            uint256 _RATE_PRECISION,
            uint256 _MAX_PROTOCOL_FEE
        );

    function addInterest(
        bool _returnAccounting
    )
        external
        returns (
            uint256 _interestEarned,
            uint256 _feesAmount,
            uint256 _feesShare,
            CurrentRateInfo memory _currentRateInfo,
            VaultAccount memory _totalAsset,
            VaultAccount memory _totalBorrow
        );
}

contract FraxLendStrategy is BaseStrategy {
    using SafeERC20 for ERC20;

    IFraxLend public immutable pair;
    // FraxLend pair version
    uint256 public immutable version;

    // Amount of deposits we need before depositing
    uint256 public immutable depositThreshold;
    // Bool if we have met the depositThreshold
    bool public thresholdMet;

    // Timestamp of when withdraws will be enabled
    uint256 public timeToUnlock;
    // If the timeToUnlock is still able to be set. (false == can still be set.)
    bool public freezeTimeToUnlock;

    constructor(
        address _asset,
        address _pair,
        string memory _name,
        uint256 _version,
        uint256 _depositThreshold,
        uint256 _timeToUnlock
    ) BaseStrategy(_asset, _name) {
        require(_version != 0, "invalid version");
        // Set pair address
        pair = IFraxLend(_pair);
        // Set pair version
        version = _version;
        // Set depositThreshold value
        depositThreshold = _depositThreshold;
        // Set initial time to unlock
        timeToUnlock = _timeToUnlock;
        // Approve the pair for FRAX
        ERC20(_asset).safeApprove(address(pair), type(uint256).max);
    }

    /*//////////////////////////////////////////////////////////////
                NEEDED TO BE OVERRIDEN BY STRATEGIST
    //////////////////////////////////////////////////////////////*/

    /**
     * @dev Should deploy up to '_amount' of 'asset' in the yield source.
     *
     * This function is called at the end of a {deposit} or {mint}
     * call. Meaning that unless a whitelist is implemented it will
     * be entirely permsionless and thus can be sandwhiched or otherwise
     * manipulated.
     *
     * @param _amount The amount of 'asset' that the strategy should attemppt
     * to deposit in the yield source.
     */
    function _deployFunds(uint256 _amount) internal override {
        // We don't deposit until the threshold is met.
        if (thresholdMet) {
            pair.deposit(_amount, address(this));

            // Amount will include all idle funds if not deposited yet.
        } else if (_amount > depositThreshold) {
            // Set the bool for easy checks in the future.
            thresholdMet = true;
            pair.deposit(_amount, address(this));
        }
    }

    /**
     * @dev Will attempt to free the '_amount' of 'asset'.
     *
     * The amount of 'asset' that is already loose has already
     * been accounted for.
     *
     * This function is called during {withdraw} and {redeem} calls.
     * Meaning that unless a whitelist is implemented it will be
     * entirely permsionless and thus can be sandwhiched or otherwise
     * manipulated.
     *
     * Should not rely on asset.balanceOf(address(this)) calls other than
     * for diff accounting puroposes.
     *
     * Any difference between `_amount` and what is actually freed will be
     * counted as a loss and passed on to the withdrawer. This means
     * care should be taken in times of illiquidity. It may be better to revert
     * if withdraws are simply illiquid so not to realize incorrect losses.
     *
     * @param _amount, The amount of 'asset' to be freed.
     */
    function _freeFunds(uint256 _amount) internal override {
        // Only proccess withdraws if we have unlocked the stratey
        if (block.timestamp >= timeToUnlock) {
            // Accrue interest for conversion.
            if (version < 3) {
                pair.addInterest();
                pair.redeem(
                    pair.toAssetShares(_amount, false),
                    address(this),
                    address(this)
                );
            } else {
                IFraxLendV3(address(pair)).addInterest(false);
                pair.redeem(
                    IFraxLendV3(address(pair)).toAssetShares(_amount, false, false),
                    address(this),
                    address(this)
                );
            }
        } else {
            // This should never happen but we check just in case and
            // revert so we don't record an incorrect loss.
            require(false, "Locked!");
        }
    }