// SPDX-License-Identifier: AGPL-3.0-only
pragma solidity 0.8.11;

// External references
import { ERC20 } from "@rari-capital/solmate/src/tokens/ERC20.sol";
import { SafeTransferLib } from "@rari-capital/solmate/src/utils/SafeTransferLib.sol";
import { IERC3156FlashLender } from "../external/flashloan/IERC3156FlashLender.sol";
import { IERC3156FlashBorrower } from "../external/flashloan/IERC3156FlashBorrower.sol";

// Internal references
import { Divider } from "../Divider.sol";
import { Errors } from "@sense-finance/v1-utils/src/libs/Errors.sol";

/// @title Assign value to Target tokens
abstract contract BaseAdapter is IERC3156FlashLender {
    using SafeTransferLib for ERC20;

    /* ========== CONSTANTS ========== */

    bytes32 public constant CALLBACK_SUCCESS = keccak256("ERC3156FlashBorrower.onFlashLoan");

    /* ========== PUBLIC IMMUTABLES ========== */

    /// @notice Sense core Divider address
    address public immutable divider;

    /// @notice Target token to divide
    address public immutable target;

    /// @notice Underlying for the Target
    address public immutable underlying;

    /// @notice Oracle address
    address public immutable oracle;

    /// @notice Token to stake at issuance
    address public immutable stake;

    /// @notice Amount to stake at issuance
    uint256 public immutable stakeSize;

    /// @notice Min maturity (seconds after block.timstamp)
    uint256 public immutable minm;

    /// @notice Max maturity (seconds after block.timstamp)
    uint256 public immutable maxm;

    /// @notice 0 for monthly, 1 for weekly
    uint256 public immutable mode;

    /// @notice Issuance fee
    uint256 public immutable ifee;

    /// @notice WAD number representing the percentage of the total
    /// principal that's set aside for Yield Tokens (e.g. 0.1e18 means that 10% of the principal is reserved).
    /// @notice If `0`, it means no principal is set aside for Yield Tokens
    uint256 public immutable tilt;

    /// @notice The number this function returns will be used to determine its access by checking for binary
    /// digits using the following scheme: <onRedeem(y/n)><collect(y/n)><combine(y/n)><issue(y/n)>
    /// (e.g. 0101 enables `collect` and `issue`, but not `combine`)
    uint256 public immutable level;

    /* ========== METADATA STORAGE ========== */

    string public name;

    string public symbol;

    constructor(
        address _divider,
        address _target,
        address _underlying,
        address _oracle,
        uint256 _ifee,
        address _stake,
        uint256 _stakeSize,
        uint256 _minm,
        uint256 _maxm,
        uint256 _mode,
        uint256 _tilt,
        uint256 _level
    ) {
        // Sanity check
        if (_minm >= _maxm) revert Errors.InvalidMaturityOffsets();
        divider = _divider;
        target = _target;
        underlying = _underlying;
        oracle = _oracle;
        ifee = _ifee;
        stake = _stake;
        stakeSize = _stakeSize;
        minm = _minm;
        maxm = _maxm;
        mode = _mode;
        tilt = _tilt;
        name = string(abi.encodePacked(ERC20(_target).name(), " Adapter"));
        symbol = string(abi.encodePacked(ERC20(_target).symbol(), "-adapter"));
        level = _level;

        ERC20(_target).approve(_divider, type(uint256).max);
        ERC20(_stake).approve(_divider, type(uint256).max);
    }

    /// @notice Loan `amount` target to `receiver`, and takes it back after the callback.
    /// @param receiver The contract receiving target, needs to implement the
    /// `onFlashLoan(address user, address adapter, uint256 maturity, uint256 amount)` interface.
    /// @param amount The amount of target lent.
    /// @param data (encoded adapter address, maturity and YT amount the use has sent in)
    function flashLoan(
        IERC3156FlashBorrower receiver,
        address, /* fee */
        uint256 amount,
        bytes calldata data
    ) external returns (bool) {
        if (Divider(divider).periphery() != msg.sender) revert Errors.OnlyPeriphery();
        ERC20(target).safeTransfer(address(receiver), amount);
        bytes32 keccak = IERC3156FlashBorrower(receiver).onFlashLoan(msg.sender, target, amount, 0, data);
        if (keccak != CALLBACK_SUCCESS) revert Errors.FlashCallbackFailed();
        ERC20(target).safeTransferFrom(address(receiver), address(this), amount);
        return true;
    }

    /* ========== REQUIRED VALUE GETTERS ========== */

    /// @notice Calculate and return this adapter's Scale value for the current timestamp. To be overriden by child contracts
    /// @dev For some Targets, such as cTokens, this is simply the exchange rate, or `supply cToken / supply underlying`
    /// @dev For other Targets, such as AMM LP shares, specialized logic will be required
    /// @dev This function _must_ return a WAD number representing the current exchange rate
    /// between the Target and the Underlying.
    /// @return value WAD Scale value
    function scale() external virtual returns (uint256);

    /// @notice Cached scale value getter
    /// @dev For situations where you need scale from a view function
    function scaleStored() external view virtual returns (uint256);

    /// @notice Returns the current price of the underlying in ETH terms
    function getUnderlyingPrice() external view virtual returns (uint256);

    /* ========== REQUIRED UTILITIES ========== */

    /// @notice Deposits underlying `amount`in return for target. Must be overriden by child contracts
    /// @param amount Underlying amount
    /// @return amount of target returned
    function wrapUnderlying(uint256 amount) external virtual returns (uint256);

    /// @notice Deposits target `amount`in return for underlying. Must be overriden by child contracts
    /// @param amount Target amount
    /// @return amount of underlying returned
    function unwrapTarget(uint256 amount) external virtual returns (uint256);

    function flashFee(address token, uint256) external view returns (uint256) {
        if (token != target) revert Errors.TokenNotSupported();
        return 0;
    }

    function maxFlashLoan(address token) external view override returns (uint256) {
        return ERC20(token).balanceOf(address(this));
    }

    /* ========== OPTIONAL HOOKS ========== */

    /// @notice Notification whenever the Divider adds or removes Target
    function notify(
        address, /* usr */
        uint256, /* amt */
        bool /* join */
    ) public virtual {
        return;
    }

    /// @notice Hook called whenever a user redeems PT
    function onRedeem(
        uint256, /* uBal */
        uint256, /* mscale */
        uint256, /* maxscale */
        uint256 /* tBal */
    ) public virtual {
        return;
    }

    /* ========== PUBLIC STORAGE ACCESSORS ========== */

    function getMaturityBounds() external view returns (uint256, uint256) {
        return (minm, maxm);
    }

    function getStakeAndTarget()
        external
        view
        returns (
            address,
            address,
            uint256
        )
    {
        return (target, stake, stakeSize);
    }
}

// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

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

    function _msgData() internal view virtual returns (bytes calldata) {
        return msg.data;
    }
}

pragma solidity 0.8.11;

/// @author Taken from: https://github.com/bokkypoobah/BokkyPooBahsDateTimeLibrary
library DateTime {
    uint256 constant SECONDS_PER_DAY = 24 * 60 * 60;
    uint256 constant SECONDS_PER_HOUR = 60 * 60;
    uint256 constant SECONDS_PER_MINUTE = 60;
    int256 constant OFFSET19700101 = 2440588;

    function timestampToDate(uint256 timestamp)
        internal
        pure
        returns (
            uint256 year,
            uint256 month,
            uint256 day
        )
    {
        (year, month, day) = _daysToDate(timestamp / SECONDS_PER_DAY);
    }

    function timestampToDateTime(uint256 timestamp)
        internal
        pure
        returns (
            uint256 year,
            uint256 month,
            uint256 day,
            uint256 hour,
            uint256 minute,
            uint256 second
        )
    {
        (year, month, day) = _daysToDate(timestamp / SECONDS_PER_DAY);
        uint256 secs = timestamp % SECONDS_PER_DAY;
        hour = secs / SECONDS_PER_HOUR;
        secs = secs % SECONDS_PER_HOUR;
        minute = secs / SECONDS_PER_MINUTE;
        second = secs % SECONDS_PER_MINUTE;
    }

    function toDateString(uint256 _timestamp)
        internal
        pure
        returns (
            string memory d,
            string memory m,
            string memory y
        )
    {
        (uint256 year, uint256 month, uint256 day) = timestampToDate(_timestamp);
        d = uintToString(day);
        m = uintToString(month);
        y = uintToString(year);
        // append a 0 to numbers < 10 so we should, e.g, 01 instead of just 1
        if (day < 10) d = string(abi.encodePacked("0", d));
        if (month < 10) m = string(abi.encodePacked("0", m));
    }

    function format(uint256 _timestamp) internal pure returns (string memory datestring) {
        string[12] memory months = [
            "Jan",
            "Feb",
            "Mar",
            "Apr",
            "May",
            "June",
            "July",
            "Aug",
            "Sept",
            "Oct",
            "Nov",
            "Dec"
        ];
        (uint256 year, uint256 month, uint256 day) = timestampToDate(_timestamp);
        uint256 last = day % 10;
        string memory suffix = "th";
        if (day < 11 || day > 20) {
            if (last == 1) suffix = "st";
            if (last == 2) suffix = "nd";
            if (last == 3) suffix = "rd";
        }
        return string(abi.encodePacked(uintToString(day), suffix, " ", months[month - 1], " ", uintToString(year)));
    }

    function getDayOfWeek(uint256 timestamp) internal pure returns (uint256 dayOfWeek) {
        uint256 _days = timestamp / SECONDS_PER_DAY;
        dayOfWeek = ((_days + 3) % 7) + 1;
    }

    /// Taken from https://stackoverflow.com/questions/47129173/how-to-convert-uint-to-string-in-solidity
    function uintToString(uint256 _i) internal pure returns (string memory _uintAsString) {
        if (_i == 0) return "0";
        uint256 j = _i;
        uint256 len;
        while (j != 0) {
            len++;
            j /= 10;
        }
        bytes memory bstr = new bytes(len);
        uint256 k = len;
        while (_i != 0) {
            k = k - 1;
            uint8 temp = (48 + uint8(_i - (_i / 10) * 10));
            bytes1 b1 = bytes1(temp);
            bstr[k] = b1;
            _i /= 10;
        }
        return string(bstr);
    }

    // ------------------------------------------------------------------------
    // Calculate the number of days from 1970/01/01 to year/month/day using
    // the date conversion algorithm from
    //   http://aa.usno.navy.mil/faq/docs/JD_Formula.php
    // and subtracting the offset 2440588 so that 1970/01/01 is day 0
    //
    // days = day
    //      - 32075
    //      + 1461 * (year + 4800 + (month - 14) / 12) / 4
    //      + 367 * (month - 2 - (month - 14) / 12 * 12) / 12
    //      - 3 * ((year + 4900 + (month - 14) / 12) / 100) / 4
    //      - offset
    // ------------------------------------------------------------------------
    function _daysFromDate(
        uint256 year,
        uint256 month,
        uint256 day
    ) internal pure returns (uint256 _days) {
        require(year >= 1970);
        int256 _year = int256(year);
        int256 _month = int256(month);
        int256 _day = int256(day);

        int256 __days = _day -
            32075 +
            (1461 * (_year + 4800 + (_month - 14) / 12)) /
            4 +
            (367 * (_month - 2 - ((_month - 14) / 12) * 12)) /
            12 -
            (3 * ((_year + 4900 + (_month - 14) / 12) / 100)) /
            4 -
            OFFSET19700101;

        _days = uint256(__days);
    }

    // ------------------------------------------------------------------------
    // Calculate year/month/day from the number of days since 1970/01/01 using
    // the date conversion algorithm from
    //   http://aa.usno.navy.mil/faq/docs/JD_Formula.php
    // and adding the offset 2440588 so that 1970/01/01 is day 0
    //
    // int L = days + 68569 + offset
    // int N = 4 * L / 146097
    // L = L - (146097 * N + 3) / 4
    // year = 4000 * (L + 1) / 1461001
    // L = L - 1461 * year / 4 + 31
    // month = 80 * L / 2447
    // dd = L - 2447 * month / 80
    // L = month / 11
    // month = month + 2 - 12 * L
    // year = 100 * (N - 49) + year + L
    // ------------------------------------------------------------------------
    function _daysToDate(uint256 _days)
        internal
        pure
        returns (
            uint256 year,
            uint256 month,
            uint256 day
        )
    {
        int256 __days = int256(_days);

        int256 L = __days + 68569 + OFFSET19700101;
        int256 N = (4 * L) / 146097;
        L = L - (146097 * N + 3) / 4;
        int256 _year = (4000 * (L + 1)) / 1461001;
        L = L - (1461 * _year) / 4 + 31;
        int256 _month = (80 * L) / 2447;
        int256 _day = L - (2447 * _month) / 80;
        L = _month / 11;
        _month = _month + 2 - 12 * L;
        _year = 100 * (N - 49) + _year + L;

        year = uint256(_year);
        month = uint256(_month);
        day = uint256(_day);
    }
}

// SPDX-License-Identifier: AGPL-3.0-only
pragma solidity 0.8.11;

// External references
import { Pausable } from "@openzeppelin/contracts/security/Pausable.sol";
import { ERC20 } from "@rari-capital/solmate/src/tokens/ERC20.sol";
import { SafeTransferLib } from "@rari-capital/solmate/src/utils/SafeTransferLib.sol";
import { ReentrancyGuard } from "@rari-capital/solmate/src/utils/ReentrancyGuard.sol";
import { DateTime } from "./external/DateTime.sol";
import { FixedMath } from "./external/FixedMath.sol";

// Internal references
import { Errors } from "@sense-finance/v1-utils/src/libs/Errors.sol";

import { Levels } from "@sense-finance/v1-utils/src/libs/Levels.sol";
import { Trust } from "@sense-finance/v1-utils/src/Trust.sol";
import { YT } from "./tokens/YT.sol";
import { Token } from "./tokens/Token.sol";
import { BaseAdapter as Adapter } from "./adapters/BaseAdapter.sol";

/// @title Sense Divider: Divide Assets in Two
/// @author fedealconada + jparklev
/// @notice You can use this contract to issue, combine, and redeem Sense ERC20 Principal and Yield Tokens
contract Divider is Trust, ReentrancyGuard, Pausable {
    using SafeTransferLib for ERC20;
    using FixedMath for uint256;
    using Levels for uint256;

    /* ========== PUBLIC CONSTANTS ========== */

    /// @notice Buffer before and after the actual maturity in which only the sponsor can settle the Series
    uint256 public constant SPONSOR_WINDOW = 3 hours;

    /// @notice Buffer after the sponsor window in which anyone can settle the Series
    uint256 public constant SETTLEMENT_WINDOW = 3 hours;

    /// @notice 5% issuance fee cap
    uint256 public constant ISSUANCE_FEE_CAP = 0.05e18;

    /* ========== PUBLIC MUTABLE STORAGE ========== */

    address public periphery;

    /// @notice Sense community multisig
    address public immutable cup;

    /// @notice Principal/Yield tokens deployer
    address public immutable tokenHandler;

    /// @notice Permissionless flag
    bool public permissionless;

    /// @notice Guarded launch flag
    bool public guarded = true;

    /// @notice Number of adapters (including turned off)
    uint248 public adapterCounter;

    /// @notice adapter ID -> adapter address
    mapping(uint256 => address) public adapterAddresses;

    /// @notice adapter data
    mapping(address => AdapterMeta) public adapterMeta;

    /// @notice adapter -> maturity -> Series
    mapping(address => mapping(uint256 => Series)) public series;

    /// @notice adapter -> maturity -> user -> lscale (last scale)
    mapping(address => mapping(uint256 => mapping(address => uint256))) public lscales;

    /* ========== DATA STRUCTURES ========== */

    struct Series {
        // Principal ERC20 token
        address pt;
        // Timestamp of series initialization
        uint48 issuance;
        // Yield ERC20 token
        address yt;
        // % of underlying principal initially reserved for Yield
        uint96 tilt;
        // Actor who initialized the Series
        address sponsor;
        // Tracks fees due to the series' settler
        uint256 reward;
        // Scale at issuance
        uint256 iscale;
        // Scale at maturity
        uint256 mscale;
        // Max scale value from this series' lifetime
        uint256 maxscale;
    }

    struct AdapterMeta {
        // Adapter ID
        uint248 id;
        // Adapter enabled/disabled
        bool enabled;
        // Max amount of Target allowed to be issued
        uint256 guard;
        // Adapter level
        uint248 level;
    }

    constructor(address _cup, address _tokenHandler) Trust(msg.sender) {
        cup = _cup;
        tokenHandler = _tokenHandler;
    }

    /* ========== MUTATIVE FUNCTIONS ========== */

    /// @notice Enable an adapter
    /// @dev when permissionless is disabled, only the Periphery can onboard adapters
    /// @dev after permissionless is enabled, anyone can onboard adapters
    /// @param adapter Adapter's address
    function addAdapter(address adapter) external whenNotPaused {
        if (!permissionless && msg.sender != periphery) revert Errors.OnlyPermissionless();
        if (adapterMeta[adapter].id > 0 && !adapterMeta[adapter].enabled) revert Errors.InvalidAdapter();
        _setAdapter(adapter, true);
    }

    /// @notice Initializes a new Series
    /// @dev Deploys two ERC20 contracts, one for PTs and the other one for YTs
    /// @dev Transfers some fixed amount of stake asset to this contract
    /// @param adapter Adapter to associate with the Series
    /// @param maturity Maturity date for the new Series, in units of unix time
    /// @param sponsor Sponsor of the Series that puts up a token stake and receives the issuance fees
    function initSeries(
        address adapter,
        uint256 maturity,
        address sponsor
    ) external nonReentrant whenNotPaused returns (address pt, address yt) {
        if (periphery != msg.sender) revert Errors.OnlyPeriphery();
        if (!adapterMeta[adapter].enabled) revert Errors.InvalidAdapter();
        if (_exists(adapter, maturity)) revert Errors.DuplicateSeries();
        if (!_isValid(adapter, maturity)) revert Errors.InvalidMaturity();

        // Transfer stake asset stake from caller to adapter
        (address target, address stake, uint256 stakeSize) = Adapter(adapter).getStakeAndTarget();

        // Deploy Principal & Yield Tokens for this new Series
        (pt, yt) = TokenHandler(tokenHandler).deploy(adapter, adapterMeta[adapter].id, maturity);

        // Initialize the new Series struct
        uint256 scale = Adapter(adapter).scale();

        series[adapter][maturity].pt = pt;
        series[adapter][maturity].issuance = uint48(block.timestamp);
        series[adapter][maturity].yt = yt;
        series[adapter][maturity].tilt = uint96(Adapter(adapter).tilt());
        series[adapter][maturity].sponsor = sponsor;
        series[adapter][maturity].iscale = scale;
        series[adapter][maturity].maxscale = scale;

        ERC20(stake).safeTransferFrom(msg.sender, adapter, stakeSize);

        emit SeriesInitialized(adapter, maturity, pt, yt, sponsor, target);
    }

    /// @notice Settles a Series and transfers the settlement reward to the caller
    /// @dev The Series' sponsor has a grace period where only they can settle the Series
    /// @dev After that, the reward becomes MEV
    /// @param adapter Adapter to associate with the Series
    /// @param maturity Maturity date for the new Series
    function settleSeries(address adapter, uint256 maturity) external nonReentrant whenNotPaused {
        if (!adapterMeta[adapter].enabled) revert Errors.InvalidAdapter();
        if (!_exists(adapter, maturity)) revert Errors.SeriesDoesNotExist();
        if (_settled(adapter, maturity)) revert Errors.AlreadySettled();
        if (!_canBeSettled(adapter, maturity)) revert Errors.OutOfWindowBoundaries();

        // The maturity scale value is all a Series needs for us to consider it "settled"
        uint256 mscale = Adapter(adapter).scale();
        series[adapter][maturity].mscale = mscale;

        if (mscale > series[adapter][maturity].maxscale) {
            series[adapter][maturity].maxscale = mscale;
        }

        // Reward the caller for doing the work of settling the Series at around the correct time
        (address target, address stake, uint256 stakeSize) = Adapter(adapter).getStakeAndTarget();
        ERC20(target).safeTransferFrom(adapter, msg.sender, series[adapter][maturity].reward);
        ERC20(stake).safeTransferFrom(adapter, msg.sender, stakeSize);

        emit SeriesSettled(adapter, maturity, msg.sender);
    }

    /// @notice Mint Principal & Yield Tokens of a specific Series
    /// @param adapter Adapter address for the Series
    /// @param maturity Maturity date for the Series [unix time]
    /// @param tBal Balance of Target to deposit
    /// @dev The balance of PTs and YTs minted will be the same value in units of underlying (less fees)
    function issue(
        address adapter,
        uint256 maturity,
        uint256 tBal
    ) external nonReentrant whenNotPaused returns (uint256 uBal) {
        if (!adapterMeta[adapter].enabled) revert Errors.InvalidAdapter();
        if (!_exists(adapter, maturity)) revert Errors.SeriesDoesNotExist();
        if (_settled(adapter, maturity)) revert Errors.IssueOnSettle();

        uint256 level = adapterMeta[adapter].level;
        if (level.issueRestricted() && msg.sender != adapter) revert Errors.IssuanceRestricted();

        ERC20 target = ERC20(Adapter(adapter).target());

        // Take the issuance fee out of the deposited Target, and put it towards the settlement reward
        uint256 issuanceFee = Adapter(adapter).ifee();
        if (issuanceFee > ISSUANCE_FEE_CAP) revert Errors.IssuanceFeeCapExceeded();
        uint256 fee = tBal.fmul(issuanceFee);

        unchecked {
            // Safety: bounded by the Target's total token supply
            series[adapter][maturity].reward += fee;
        }
        uint256 tBalSubFee = tBal - fee;

        // Ensure the caller won't hit the issuance cap with this action
        unchecked {
            // Safety: bounded by the Target's total token supply
            if (guarded && target.balanceOf(adapter) + tBal > adapterMeta[address(adapter)].guard)
                revert Errors.GuardCapReached();
        }

        // Update values on adapter
        Adapter(adapter).notify(msg.sender, tBalSubFee, true);

        uint256 scale = level.collectDisabled() ? series[adapter][maturity].iscale : Adapter(adapter).scale();

        // Determine the amount of Underlying equal to the Target being sent in (the principal)
        uBal = tBalSubFee.fmul(scale);

        // If the caller has not collected on YT before, use the current scale, otherwise
        // use the harmonic mean of the last and the current scale value
        lscales[adapter][maturity][msg.sender] = lscales[adapter][maturity][msg.sender] == 0
            ? scale
            : _reweightLScale(
                adapter,
                maturity,
                YT(series[adapter][maturity].yt).balanceOf(msg.sender),
                uBal,
                msg.sender,
                scale
            );

        // Mint equal amounts of PT and YT
        Token(series[adapter][maturity].pt).mint(msg.sender, uBal);
        YT(series[adapter][maturity].yt).mint(msg.sender, uBal);

        target.safeTransferFrom(msg.sender, adapter, tBal);

        emit Issued(adapter, maturity, uBal, msg.sender);
    }

    /// @notice Reconstitute Target by burning PT and YT
    /// @dev Explicitly burns YTs before maturity, and implicitly does it at/after maturity through `_collect()`
    /// @param adapter Adapter address for the Series
    /// @param maturity Maturity date for the Series
    /// @param uBal Balance of PT and YT to burn
    function combine(
        address adapter,
        uint256 maturity,
        uint256 uBal
    ) external nonReentrant whenNotPaused returns (uint256 tBal) {
        if (!adapterMeta[adapter].enabled) revert Errors.InvalidAdapter();
        if (!_exists(adapter, maturity)) revert Errors.SeriesDoesNotExist();

        uint256 level = adapterMeta[adapter].level;
        if (level.combineRestricted() && msg.sender != adapter) revert Errors.CombineRestricted();

        // Burn the PT
        Token(series[adapter][maturity].pt).burn(msg.sender, uBal);

        // Collect whatever excess is due
        uint256 collected = _collect(msg.sender, adapter, maturity, uBal, uBal, address(0));

        uint256 cscale = series[adapter][maturity].mscale;
        bool settled = _settled(adapter, maturity);
        if (!settled) {
            // If it's not settled, then YT won't be burned automatically in `_collect()`
            YT(series[adapter][maturity].yt).burn(msg.sender, uBal);
            // If collect has been restricted, use the initial scale, otherwise use the current scale
            cscale = level.collectDisabled()
                ? series[adapter][maturity].iscale
                : lscales[adapter][maturity][msg.sender];
        }

        // Convert from units of Underlying to units of Target
        tBal = uBal.fdiv(cscale);
        ERC20(Adapter(adapter).target()).safeTransferFrom(adapter, msg.sender, tBal);

        // Notify only when Series is not settled as when it is, the _collect() call above would trigger a _redeemYT which will call notify
        if (!settled) Adapter(adapter).notify(msg.sender, tBal, false);
        unchecked {
            // Safety: bounded by the Target's total token supply
            tBal += collected;
        }
        emit Combined(adapter, maturity, tBal, msg.sender);
    }

    /// @notice Burn PT of a Series once it's been settled
    /// @dev The balance of redeemable Target is a function of the change in Scale
    /// @param adapter Adapter address for the Series
    /// @param maturity Maturity date for the Series
    /// @param uBal Amount of PT to burn, which should be equivalent to the amount of Underlying owed to the caller
    function redeem(
        address adapter,
        uint256 maturity,
        uint256 uBal
    ) external nonReentrant whenNotPaused returns (uint256 tBal) {
        // If a Series is settled, we know that it must have existed as well, so that check is unnecessary
        if (!_settled(adapter, maturity)) revert Errors.NotSettled();

        uint256 level = adapterMeta[adapter].level;
        if (level.redeemRestricted() && msg.sender == adapter) revert Errors.RedeemRestricted();

        // Burn the caller's PT
        Token(series[adapter][maturity].pt).burn(msg.sender, uBal);

        // Principal Token holder's share of the principal = (1 - part of the principal that belongs to Yield)
        uint256 zShare = FixedMath.WAD - series[adapter][maturity].tilt;

        // If Principal Token are at a loss and Yield have some principal to help cover the shortfall,
        // take what we can from Yield Token's principal
        if (series[adapter][maturity].mscale.fdiv(series[adapter][maturity].maxscale) >= zShare) {
            tBal = (uBal * zShare) / series[adapter][maturity].mscale;
        } else {
            tBal = uBal.fdiv(series[adapter][maturity].maxscale);
        }

        if (!level.redeemHookDisabled()) {
            Adapter(adapter).onRedeem(uBal, series[adapter][maturity].mscale, series[adapter][maturity].maxscale, tBal);
        }

        ERC20(Adapter(adapter).target()).safeTransferFrom(adapter, msg.sender, tBal);
        emit PTRedeemed(adapter, maturity, tBal);
    }

    function collect(
        address usr,
        address adapter,
        uint256 maturity,
        uint256 uBalTransfer,
        address to
    ) external nonReentrant onlyYT(adapter, maturity) whenNotPaused returns (uint256 collected) {
        uint256 uBal = YT(msg.sender).balanceOf(usr);
        return _collect(usr, adapter, maturity, uBal, uBalTransfer > 0 ? uBalTransfer : uBal, to);
    }

    /// @notice Collect YT excess before, at, or after maturity
    /// @dev If `to` is set, we copy the lscale value from usr to this address
    /// @param usr User who's collecting for their YTs
    /// @param adapter Adapter address for the Series
    /// @param maturity Maturity date for the Series
    /// @param uBal yield Token balance
    /// @param uBalTransfer original transfer value
    /// @param to address to set the lscale value from usr
    function _collect(
        address usr,
        address adapter,
        uint256 maturity,
        uint256 uBal,
        uint256 uBalTransfer,
        address to
    ) internal returns (uint256 collected) {
        if (!_exists(adapter, maturity)) revert Errors.SeriesDoesNotExist();

        // If the adapter is disabled, its Yield Token can only collect
        // if associated Series has been settled, which implies that an admin
        // has backfilled it
        if (!adapterMeta[adapter].enabled && !_settled(adapter, maturity)) revert Errors.InvalidAdapter();

        Series memory _series = series[adapter][maturity];

        // Get the scale value from the last time this holder collected (default to maturity)
        uint256 lscale = lscales[adapter][maturity][usr];

        uint256 level = adapterMeta[adapter].level;
        if (level.collectDisabled()) {
            // If this Series has been settled, we ensure everyone's YT will
            // collect yield accrued since issuance
            if (_settled(adapter, maturity)) {
                lscale = series[adapter][maturity].iscale;
                // If the Series is not settled, we ensure no collections can happen
            } else {
                return 0;
            }
        }

        // If the Series has been settled, this should be their last collect, so redeem the user's Yield Tokens for them
        if (_settled(adapter, maturity)) {
            _redeemYT(usr, adapter, maturity, uBal);
        } else {
            // If we're not settled and we're past maturity + the sponsor window,
            // anyone can settle this Series so revert until someone does
            if (block.timestamp > maturity + SPONSOR_WINDOW) {
                revert Errors.CollectNotSettled();
                // Otherwise, this is a valid pre-settlement collect and we need to determine the scale value
            } else {
                uint256 cscale = Adapter(adapter).scale();
                // If this is larger than the largest scale we've seen for this Series, use it
                if (cscale > _series.maxscale) {
                    _series.maxscale = cscale;
                    lscales[adapter][maturity][usr] = cscale;
                    // If not, use the previously noted max scale value
                } else {
                    lscales[adapter][maturity][usr] = _series.maxscale;
                }
            }
        }

        // Determine how much underlying has accrued since the last time this user collected, in units of Target.
        // (Or take the last time as issuance if they haven't yet)
        //
        // Reminder: `Underlying / Scale = Target`
        // So the following equation is saying, for some amount of Underlying `u`:
        // "Balance of Target that equaled `u` at the last collection _minus_ Target that equals `u` now"
        //
        // Because maxscale must be increasing, the Target balance needed to equal `u` decreases, and that "excess"
        // is what Yield holders are collecting
        uint256 tBalNow = uBal.fdivUp(_series.maxscale); // preventive round-up towards the protocol
        uint256 tBalPrev = uBal.fdiv(lscale);
        unchecked {
            collected = tBalPrev > tBalNow ? tBalPrev - tBalNow : 0;
        }
        ERC20(Adapter(adapter).target()).safeTransferFrom(adapter, usr, collected);
        Adapter(adapter).notify(usr, collected, false); // Distribute reward tokens

        // If this collect is a part of a token transfer to another address, set the receiver's
        // last collection to a synthetic scale weighted based on the scale on their last collect,
        // the time elapsed, and the current scale
        if (to != address(0)) {
            uint256 ytBal = YT(_series.yt).balanceOf(to);
            // If receiver holds yields, we set lscale to a computed "synthetic" lscales value that,
            // for the updated yield balance, still assigns the correct amount of yield.
            lscales[adapter][maturity][to] = ytBal > 0
                ? _reweightLScale(adapter, maturity, ytBal, uBalTransfer, to, _series.maxscale)
                : _series.maxscale;
            uint256 tBalTransfer = uBalTransfer.fdiv(_series.maxscale);
            Adapter(adapter).notify(usr, tBalTransfer, false);
            Adapter(adapter).notify(to, tBalTransfer, true);
        }
        series[adapter][maturity] = _series;

        emit Collected(adapter, maturity, collected);
    }

    /// @notice calculate the harmonic mean of the current scale and the last scale,
    /// weighted by amounts associated with each
    function _reweightLScale(
        address adapter,
        uint256 maturity,
        uint256 ytBal,
        uint256 uBal,
        address receiver,
        uint256 scale
    ) internal view returns (uint256) {
        // Target Decimals * 18 Decimals [from fdiv] / (Target Decimals * 18 Decimals [from fdiv] / 18 Decimals)
        // = 18 Decimals, which is the standard for scale values
        return (ytBal + uBal).fdiv((ytBal.fdiv(lscales[adapter][maturity][receiver]) + uBal.fdiv(scale)));
    }

    function _redeemYT(
        address usr,
        address adapter,
        uint256 maturity,
        uint256 uBal
    ) internal {
        // Burn the users's YTs
        YT(series[adapter][maturity].yt).burn(usr, uBal);

        // Default principal for a YT
        uint256 tBal = 0;

        // Principal Token holder's share of the principal = (1 - part of the principal that belongs to Yield Tokens)
        uint256 zShare = FixedMath.WAD - series[adapter][maturity].tilt;

        // If PTs are at a loss and YTs had their principal cut to help cover the shortfall,
        // calculate how much YTs have left
        if (series[adapter][maturity].mscale.fdiv(series[adapter][maturity].maxscale) >= zShare) {
            tBal = uBal.fdiv(series[adapter][maturity].maxscale) - (uBal * zShare) / series[adapter][maturity].mscale;
            ERC20(Adapter(adapter).target()).safeTransferFrom(adapter, usr, tBal);
        }

        // Always notify the Adapter of the full Target balance that will no longer
        // have its rewards distributed
        Adapter(adapter).notify(usr, uBal.fdivUp(series[adapter][maturity].maxscale), false);

        emit YTRedeemed(adapter, maturity, tBal);
    }

    /* ========== ADMIN ========== */

    /// @notice Enable or disable a adapter
    /// @param adapter Adapter's address
    /// @param isOn Flag setting this adapter to enabled or disabled
    function setAdapter(address adapter, bool isOn) public requiresTrust {
        _setAdapter(adapter, isOn);
    }

    /// @notice Set adapter's guard
    /// @param adapter Adapter address
    /// @param cap The max target that can be deposited on the Adapter
    function setGuard(address adapter, uint256 cap) external requiresTrust {
        adapterMeta[adapter].guard = cap;
        emit GuardChanged(adapter, cap);
    }

    /// @notice Set guarded mode
    /// @param _guarded bool
    function setGuarded(bool _guarded) external requiresTrust {
        guarded = _guarded;
        emit GuardedChanged(_guarded);
    }

    /// @notice Set periphery's contract
    /// @param _periphery Target address
    function setPeriphery(address _periphery) external requiresTrust {
        periphery = _periphery;
        emit PeripheryChanged(_periphery);
    }

    /// @notice Set paused flag
    /// @param _paused boolean
    function setPaused(bool _paused) external requiresTrust {
        _paused ? _pause() : _unpause();
    }

    /// @notice Set permissioless mode
    /// @param _permissionless bool
    function setPermissionless(bool _permissionless) external requiresTrust {
        permissionless = _permissionless;
        emit PermissionlessChanged(_permissionless);
    }

    /// @notice Backfill a Series' Scale value at maturity if keepers failed to settle it
    /// @param adapter Adapter's address
    /// @param maturity Maturity date for the Series
    /// @param mscale Value to set as the Series' Scale value at maturity
    /// @param _usrs Values to set on lscales mapping
    /// @param _lscales Values to set on lscales mapping
    function backfillScale(
        address adapter,
        uint256 maturity,
        uint256 mscale,
        address[] calldata _usrs,
        uint256[] calldata _lscales
    ) external requiresTrust {
        if (!_exists(adapter, maturity)) revert Errors.SeriesDoesNotExist();

        uint256 cutoff = maturity + SPONSOR_WINDOW + SETTLEMENT_WINDOW;
        // Admin can never backfill before maturity
        if (block.timestamp <= cutoff) revert Errors.OutOfWindowBoundaries();

        // Set user's last scale values the Series (needed for the `collect` method)
        for (uint256 i = 0; i < _usrs.length; i++) {
            lscales[adapter][maturity][_usrs[i]] = _lscales[i];
        }

        if (mscale > 0) {
            Series memory _series = series[adapter][maturity];
            // Set the maturity scale for the Series (needed for `redeem` methods)
            series[adapter][maturity].mscale = mscale;
            if (mscale > _series.maxscale) {
                series[adapter][maturity].maxscale = mscale;
            }

            (address target, address stake, uint256 stakeSize) = Adapter(adapter).getStakeAndTarget();

            address stakeDst = adapterMeta[adapter].enabled ? cup : _series.sponsor;
            ERC20(target).safeTransferFrom(adapter, cup, _series.reward);
            series[adapter][maturity].reward = 0;
            ERC20(stake).safeTransferFrom(adapter, stakeDst, stakeSize);
        }

        emit Backfilled(adapter, maturity, mscale, _usrs, _lscales);
    }

    /* ========== INTERNAL VIEWS ========== */

    function _exists(address adapter, uint256 maturity) internal view returns (bool) {
        return series[adapter][maturity].pt != address(0);
    }

    function _settled(address adapter, uint256 maturity) internal view returns (bool) {
        return series[adapter][maturity].mscale > 0;
    }

    function _canBeSettled(address adapter, uint256 maturity) internal view returns (bool) {
        uint256 cutoff = maturity + SPONSOR_WINDOW + SETTLEMENT_WINDOW;
        // If the sender is the sponsor for the Series
        if (msg.sender == series[adapter][maturity].sponsor) {
            return maturity - SPONSOR_WINDOW <= block.timestamp && cutoff >= block.timestamp;
        } else {
            return maturity + SPONSOR_WINDOW < block.timestamp && cutoff >= block.timestamp;
        }
    }

    function _isValid(address adapter, uint256 maturity) internal view returns (bool) {
        (uint256 minm, uint256 maxm) = Adapter(adapter).getMaturityBounds();
        if (maturity < block.timestamp + minm || maturity > block.timestamp + maxm) return false;
        (, , uint256 day, uint256 hour, uint256 minute, uint256 second) = DateTime.timestampToDateTime(maturity);

        if (hour != 0 || minute != 0 || second != 0) return false;
        uint256 mode = Adapter(adapter).mode();
        if (mode == 0) {
            return day == 1;
        }
        if (mode == 1) {
            return DateTime.getDayOfWeek(maturity) == 1;
        }
        return false;
    }

    /* ========== INTERNAL UTILS ========== */

    function _setAdapter(address adapter, bool isOn) internal {
        AdapterMeta memory am = adapterMeta[adapter];
        if (am.enabled == isOn) revert Errors.ExistingValue();
        am.enabled = isOn;

        // If this adapter is being added for the first time
        if (isOn && am.id == 0) {
            am.id = ++adapterCounter;
            adapterAddresses[am.id] = adapter;
        }

        // Set level and target (can only be done once);
        am.level = uint248(Adapter(adapter).level());
        adapterMeta[adapter] = am;
        emit AdapterChanged(adapter, am.id, isOn);
    }

    /* ========== PUBLIC GETTERS ========== */

    /// @notice Returns address of Principal Token
    function pt(address adapter, uint256 maturity) public view returns (address) {
        return series[adapter][maturity].pt;
    }

    /// @notice Returns address of Yield Token
    function yt(address adapter, uint256 maturity) public view returns (address) {
        return series[adapter][maturity].yt;
    }

    function mscale(address adapter, uint256 maturity) public view returns (uint256) {
        return series[adapter][maturity].mscale;
    }

    /* ========== MODIFIERS ========== */

    modifier onlyYT(address adapter, uint256 maturity) {
        if (series[adapter][maturity].yt != msg.sender) revert Errors.OnlyYT();
        _;
    }

    /* ========== LOGS ========== */

    /// @notice Admin
    event Backfilled(
        address indexed adapter,
        uint256 indexed maturity,
        uint256 mscale,
        address[] _usrs,
        uint256[] _lscales
    );
    event GuardChanged(address indexed adapter, uint256 cap);
    event AdapterChanged(address indexed adapter, uint256 indexed id, bool indexed isOn);
    event PeripheryChanged(address indexed periphery);

    /// @notice Series lifecycle
    /// *---- beginning
    event SeriesInitialized(
        address adapter,
        uint256 indexed maturity,
        address pt,
        address yt,
        address indexed sponsor,
        address indexed target
    );
    /// -***- middle
    event Issued(address indexed adapter, uint256 indexed maturity, uint256 balance, address indexed sender);
    event Combined(address indexed adapter, uint256 indexed maturity, uint256 balance, address indexed sender);
    event Collected(address indexed adapter, uint256 indexed maturity, uint256 collected);
    /// ----* end
    event SeriesSettled(address indexed adapter, uint256 indexed maturity, address indexed settler);
    event PTRedeemed(address indexed adapter, uint256 indexed maturity, uint256 redeemed);
    event YTRedeemed(address indexed adapter, uint256 indexed maturity, uint256 redeemed);
    /// *----* misc
    event GuardedChanged(bool indexed guarded);
    event PermissionlessChanged(bool indexed permissionless);
}

contract TokenHandler is Trust {
    /// @notice Program state
    address public divider;

    constructor() Trust(msg.sender) {}

    function init(address _divider) external requiresTrust {
        if (divider != address(0)) revert Errors.AlreadyInitialized();
        divider = _divider;
    }

    function deploy(
        address adapter,
        uint248 id,
        uint256 maturity
    ) external returns (address pt, address yt) {
        if (msg.sender != divider) revert Errors.OnlyDivider();

        ERC20 target = ERC20(Adapter(adapter).target());
        uint8 decimals = target.decimals();
        string memory symbol = target.symbol();
        (string memory d, string memory m, string memory y) = DateTime.toDateString(maturity);
        string memory date = DateTime.format(maturity);
        string memory datestring = string(abi.encodePacked(d, "-", m, "-", y));
        string memory adapterId = DateTime.uintToString(id);
        pt = address(
            new Token(
                string(abi.encodePacked(date, " ", symbol, " Sense Principal Token, A", adapterId)),
                string(abi.encodePacked("sP-", symbol, ":", datestring, ":", adapterId)),
                decimals,
                divider
            )
        );

        yt = address(
            new YT(
                adapter,
                maturity,
                string(abi.encodePacked(date, " ", symbol, " Sense Yield Token, A", adapterId)),
                string(abi.encodePacked("sY-", symbol, ":", datestring, ":", adapterId)),
                decimals,
                divider
            )
        );
    }
}

// SPDX-License-Identifier: AGPL-3.0-only
pragma solidity >=0.8.0;

/// @notice Modern and gas efficient ERC20 + EIP-2612 implementation.
/// @author Solmate (https://github.com/Rari-Capital/solmate/blob/main/src/tokens/ERC20.sol)
/// @author Modified from Uniswap (https://github.com/Uniswap/uniswap-v2-core/blob/master/contracts/UniswapV2ERC20.sol)
/// @dev Do not manually set balances without updating totalSupply, as the sum of all user balances must not exceed it.
abstract contract ERC20 {
    /*///////////////////////////////////////////////////////////////
                                  EVENTS
    //////////////////////////////////////////////////////////////*/

    event Transfer(address indexed from, address indexed to, uint256 amount);

    event Approval(address indexed owner, address indexed spender, uint256 amount);

    /*///////////////////////////////////////////////////////////////
                             METADATA STORAGE
    //////////////////////////////////////////////////////////////*/

    string public name;

    string public symbol;

    uint8 public immutable decimals;

    /*///////////////////////////////////////////////////////////////
                              ERC20 STORAGE
    //////////////////////////////////////////////////////////////*/

    uint256 public totalSupply;

    mapping(address => uint256) public balanceOf;

    mapping(address => mapping(address => uint256)) public allowance;

    /*///////////////////////////////////////////////////////////////
                             EIP-2612 STORAGE
    //////////////////////////////////////////////////////////////*/

    bytes32 public constant PERMIT_TYPEHASH =
        keccak256("Permit(address owner,address spender,uint256 value,uint256 nonce,uint256 deadline)");

    uint256 internal immutable INITIAL_CHAIN_ID;

    bytes32 internal immutable INITIAL_DOMAIN_SEPARATOR;

    mapping(address => uint256) public nonces;

    /*///////////////////////////////////////////////////////////////
                               CONSTRUCTOR
    //////////////////////////////////////////////////////////////*/

    constructor(
        string memory _name,
        string memory _symbol,
        uint8 _decimals
    ) {
        name = _name;
        symbol = _symbol;
        decimals = _decimals;

        INITIAL_CHAIN_ID = block.chainid;
        INITIAL_DOMAIN_SEPARATOR = computeDomainSeparator();
    }

    /*///////////////////////////////////////////////////////////////
                              ERC20 LOGIC
    //////////////////////////////////////////////////////////////*/

    function approve(address spender, uint256 amount) public virtual returns (bool) {
        allowance[msg.sender][spender] = amount;

        emit Approval(msg.sender, spender, amount);

        return true;
    }

    function transfer(address to, uint256 amount) public virtual returns (bool) {
        balanceOf[msg.sender] -= amount;

        // Cannot overflow because the sum of all user
        // balances can't exceed the max uint256 value.
        unchecked {
            balanceOf[to] += amount;
        }

        emit Transfer(msg.sender, to, amount);

        return true;
    }

    function transferFrom(
        address from,
        address to,
        uint256 amount
    ) public virtual returns (bool) {
        uint256 allowed = allowance[from][msg.sender]; // Saves gas for limited approvals.

        if (allowed != type(uint256).max) allowance[from][msg.sender] = allowed - amount;

        balanceOf[from] -= amount;

        // Cannot overflow because the sum of all user
        // balances can't exceed the max uint256 value.
        unchecked {
            balanceOf[to] += amount;
        }

        emit Transfer(from, to, amount);

        return true;
    }

    /*///////////////////////////////////////////////////////////////
                              EIP-2612 LOGIC
    //////////////////////////////////////////////////////////////*/

    function permit(
        address owner,
        address spender,
        uint256 value,
        uint256 deadline,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) public virtual {
        require(deadline >= block.timestamp, "PERMIT_DEADLINE_EXPIRED");

        // Unchecked because the only math done is incrementing
        // the owner's nonce which cannot realistically overflow.
        unchecked {
            bytes32 digest = keccak256(
                abi.encodePacked(
                    "\x19\x01",
                    DOMAIN_SEPARATOR(),
                    keccak256(abi.encode(PERMIT_TYPEHASH, owner, spender, value, nonces[owner]++, deadline))
                )
            );

            address recoveredAddress = ecrecover(digest, v, r, s);

            require(recoveredAddress != address(0) && recoveredAddress == owner, "INVALID_SIGNER");

            allowance[recoveredAddress][spender] = value;
        }

        emit Approval(owner, spender, value);
    }

    function DOMAIN_SEPARATOR() public view virtual returns (bytes32) {
        return block.chainid == INITIAL_CHAIN_ID ? INITIAL_DOMAIN_SEPARATOR : computeDomainSeparator();
    }

    function computeDomainSeparator() internal view virtual returns (bytes32) {
        return
            keccak256(
                abi.encode(
                    keccak256("EIP712Domain(string name,string version,uint256 chainId,address verifyingContract)"),
                    keccak256(bytes(name)),
                    keccak256("1"),
                    block.chainid,
                    address(this)
                )
            );
    }

    /*///////////////////////////////////////////////////////////////
                       INTERNAL MINT/BURN LOGIC
    //////////////////////////////////////////////////////////////*/

    function _mint(address to, uint256 amount) internal virtual {
        totalSupply += amount;

        // Cannot overflow because the sum of all user
        // balances can't exceed the max uint256 value.
        unchecked {
            balanceOf[to] += amount;
        }

        emit Transfer(address(0), to, amount);
    }

    function _burn(address from, uint256 amount) internal virtual {
        balanceOf[from] -= amount;

        // Cannot underflow because a user's balance
        // will never be larger than the total supply.
        unchecked {
            totalSupply -= amount;
        }

        emit Transfer(from, address(0), amount);
    }
}

// SPDX-License-Identifier: AGPL-3.0-only
pragma solidity >=0.8.4;

library Errors {
    // Auth
    error CombineRestricted();
    error IssuanceRestricted();
    error NotAuthorized();
    error OnlyYT();
    error OnlyDivider();
    error OnlyPeriphery();
    error OnlyPermissionless();
    error RedeemRestricted();
    error Untrusted();

    // Adapters
    error TokenNotSupported();
    error FlashCallbackFailed();
    error InvalidMaturityOffsets();
    error SenderNotEligible();
    error TargetMismatch();
    error TargetNotSupported();

    // Divider
    error AlreadySettled();
    error CollectNotSettled();
    error GuardCapReached();
    error IssuanceFeeCapExceeded();
    error IssueOnSettle();
    error NotSettled();

    // Input & validations
    error AlreadyInitialized();
    error DuplicateSeries();
    error ExistingValue();
    error InvalidAdapter();
    error InvalidMaturity();
    error InvalidParam();
    error OutOfWindowBoundaries();
    error SeriesDoesNotExist();
    error SwapTooSmall();
    error TargetParamsNotSet();
    error PoolParamsNotSet();
    error PTParamsNotSet();

    // Periphery
    error FactoryNotSupported();
    error FlashBorrowFailed();
    error FlashUntrustedBorrower();
    error FlashUntrustedLoanInitiator();
    error UnexpectedSwapAmount();

    // Fuse
    error AdapterNotSet();
    error FailedBecomeAdmin();
    error FailedAddTargetMarket();
    error FailedToAddPTMarket();
    error FailedAddLpMarket();
    error OracleNotReady();
    error PoolAlreadyDeployed();
    error PoolNotDeployed();
    error PoolNotSet();
    error SeriesNotQueued();
    error TargetExists();
    error TargetNotInFuse();

    // Tokens
    error MintFailed();
    error RedeemFailed();
    error TransferFailed();
}

// SPDX-License-Identifier: AGPL-3.0-only
pragma solidity 0.8.11;

/// @title Fixed point arithmetic library
/// @author Taken from https://github.com/Rari-Capital/solmate/blob/main/src/utils/FixedPointMathLib.sol
library FixedMath {
    uint256 internal constant WAD = 1e18;
    uint256 internal constant RAY = 1e27;

    function fmul(
        uint256 x,
        uint256 y,
        uint256 baseUnit
    ) internal pure returns (uint256) {
        return mulDivDown(x, y, baseUnit); // Equivalent to (x * y) / baseUnit rounded down.
    }

    function fmul(uint256 x, uint256 y) internal pure returns (uint256) {
        return mulDivDown(x, y, WAD); // Equivalent to (x * y) / WAD rounded down.
    }

    function fmulUp(
        uint256 x,
        uint256 y,
        uint256 baseUnit
    ) internal pure returns (uint256) {
        return mulDivUp(x, y, baseUnit); // Equivalent to (x * y) / baseUnit rounded up.
    }

    function fmulUp(uint256 x, uint256 y) internal pure returns (uint256) {
        return mulDivUp(x, y, WAD); // Equivalent to (x * y) / WAD rounded up.
    }

    function fdiv(
        uint256 x,
        uint256 y,
        uint256 baseUnit
    ) internal pure returns (uint256) {
        return mulDivDown(x, baseUnit, y); // Equivalent to (x * baseUnit) / y rounded down.
    }

    function fdiv(uint256 x, uint256 y) internal pure returns (uint256) {
        return mulDivDown(x, WAD, y); // Equivalent to (x * WAD) / y rounded down.
    }

    function fdivUp(
        uint256 x,
        uint256 y,
        uint256 baseUnit
    ) internal pure returns (uint256) {
        return mulDivUp(x, baseUnit, y); // Equivalent to (x * baseUnit) / y rounded up.
    }

    function fdivUp(uint256 x, uint256 y) internal pure returns (uint256) {
        return mulDivUp(x, WAD, y); // Equivalent to (x * WAD) / y rounded up.
    }

    function mulDivDown(
        uint256 x,
        uint256 y,
        uint256 denominator
    ) internal pure returns (uint256 z) {
        assembly {
            // Store x * y in z for now.
            z := mul(x, y)

            // Equivalent to require(denominator != 0 && (x == 0 || (x * y) / x == y))
            if iszero(and(iszero(iszero(denominator)), or(iszero(x), eq(div(z, x), y)))) {
                revert(0, 0)
            }

            // Divide z by the denominator.
            z := div(z, denominator)
        }
    }

    function mulDivUp(
        uint256 x,
        uint256 y,
        uint256 denominator
    ) internal pure returns (uint256 z) {
        assembly {
            // Store x * y in z for now.
            z := mul(x, y)

            // Equivalent to require(denominator != 0 && (x == 0 || (x * y) / x == y))
            if iszero(and(iszero(iszero(denominator)), or(iszero(x), eq(div(z, x), y)))) {
                revert(0, 0)
            }

            // First, divide z - 1 by the denominator and add 1.
            // We allow z - 1 to underflow if z is 0, because we multiply the
            // end result by 0 if z is zero, ensuring we return 0 if z is zero.
            z := mul(iszero(iszero(z)), add(div(sub(z, 1), denominator), 1))
        }
    }
}

pragma solidity ^0.8.0;

interface IERC3156FlashBorrower {
    /// @dev Receive a flash loan.
    /// @param initiator The initiator of the loan.
    /// @param token The loan currency.
    /// @param amount The amount of tokens lent.
    /// @param fee The additional amount of tokens to repay.
    /// @param data Arbitrary data structure, intended to contain user-defined parameters.
    /// @return The keccak256 hash of "ERC3156FlashBorrower.onFlashLoan"
    function onFlashLoan(
        address initiator,
        address token,
        uint256 amount,
        uint256 fee,
        bytes calldata data
    ) external returns (bytes32);
}

pragma solidity ^0.8.0;
import "./IERC3156FlashBorrower.sol";

interface IERC3156FlashLender {
    /// @dev The amount of currency available to be lent.
    /// @param token The loan currency.
    /// @return The amount of `token` that can be borrowed.
    function maxFlashLoan(address token) external view returns (uint256);

    /// @dev The fee to be charged for a given loan.
    /// @param token The loan currency.
    /// @param amount The amount of tokens lent.
    /// @return The amount of `token` to be charged for the loan, on top of the returned principal.
    function flashFee(address token, uint256 amount) external view returns (uint256);

    /// @dev Initiate a flash loan.
    /// @param receiver The receiver of the tokens in the loan, and the receiver of the callback.
    /// @param token The loan currency.
    /// @param amount The amount of tokens lent.
    /// @param data Arbitrary data structure, intended to contain user-defined parameters.
    function flashLoan(
        IERC3156FlashBorrower receiver,
        address token,
        uint256 amount,
        bytes calldata data
    ) external returns (bool);
}

// SPDX-License-Identifier: AGPL-3.0-only
pragma solidity >=0.7.0;

library Levels {
    uint256 private constant _INIT_BIT = 0x1;
    uint256 private constant _ISSUE_BIT = 0x2;
    uint256 private constant _COMBINE_BIT = 0x4;
    uint256 private constant _COLLECT_BIT = 0x8;
    uint256 private constant _REDEEM_BIT = 0x10;
    uint256 private constant _REDEEM_HOOK_BIT = 0x20;

    function initRestricted(uint256 level) internal pure returns (bool) {
        return level & _INIT_BIT != _INIT_BIT;
    }

    function issueRestricted(uint256 level) internal pure returns (bool) {
        return level & _ISSUE_BIT != _ISSUE_BIT;
    }

    function combineRestricted(uint256 level) internal pure returns (bool) {
        return level & _COMBINE_BIT != _COMBINE_BIT;
    }

    function collectDisabled(uint256 level) internal pure returns (bool) {
        return level & _COLLECT_BIT != _COLLECT_BIT;
    }

    function redeemRestricted(uint256 level) internal pure returns (bool) {
        return level & _REDEEM_BIT != _REDEEM_BIT;
    }

    function redeemHookDisabled(uint256 level) internal pure returns (bool) {
        return level & _REDEEM_HOOK_BIT != _REDEEM_HOOK_BIT;
    }
}

// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

import "../utils/Context.sol";

/**
 * @dev Contract module which allows children to implement an emergency stop
 * mechanism that can be triggered by an authorized account.
 *
 * This module is used through inheritance. It will make available the
 * modifiers `whenNotPaused` and `whenPaused`, which can be applied to
 * the functions of your contract. Note that they will not be pausable by
 * simply including this module, only once the modifiers are put in place.
 */
abstract contract Pausable is Context {
    /**
     * @dev Emitted when the pause is triggered by `account`.
     */
    event Paused(address account);

    /**
     * @dev Emitted when the pause is lifted by `account`.
     */
    event Unpaused(address account);

    bool private _paused;

    /**
     * @dev Initializes the contract in unpaused state.
     */
    constructor() {
        _paused = false;
    }

    /**
     * @dev Returns true if the contract is paused, and false otherwise.
     */
    function paused() public view virtual returns (bool) {
        return _paused;
    }

    /**
     * @dev Modifier to make a function callable only when the contract is not paused.
     *
     * Requirements:
     *
     * - The contract must not be paused.
     */
    modifier whenNotPaused() {
        require(!paused(), "Pausable: paused");
        _;
    }

    /**
     * @dev Modifier to make a function callable only when the contract is paused.
     *
     * Requirements:
     *
     * - The contract must be paused.
     */
    modifier whenPaused() {
        require(paused(), "Pausable: not paused");
        _;
    }

    /**
     * @dev Triggers stopped state.
     *
     * Requirements:
     *
     * - The contract must not be paused.
     */
    function _pause() internal virtual whenNotPaused {
        _paused = true;
        emit Paused(_msgSender());
    }

    /**
     * @dev Returns to normal state.
     *
     * Requirements:
     *
     * - The contract must be paused.
     */
    function _unpause() internal virtual whenPaused {
        _paused = false;
        emit Unpaused(_msgSender());
    }
}

// SPDX-License-Identifier: AGPL-3.0-only
pragma solidity >=0.8.0;

/// @notice Gas optimized reentrancy protection for smart contracts.
/// @author Solmate (https://github.com/Rari-Capital/solmate/blob/main/src/utils/ReentrancyGuard.sol)
/// @author Modified from OpenZeppelin (https://github.com/OpenZeppelin/openzeppelin-contracts/blob/master/contracts/security/ReentrancyGuard.sol)
abstract contract ReentrancyGuard {
    uint256 private reentrancyStatus = 1;

    modifier nonReentrant() {
        require(reentrancyStatus == 1, "REENTRANCY");

        reentrancyStatus = 2;

        _;

        reentrancyStatus = 1;
    }
}

// SPDX-License-Identifier: AGPL-3.0-only
pragma solidity >=0.8.0;

import {ERC20} from "../tokens/ERC20.sol";

/// @notice Safe ETH and ERC20 transfer library that gracefully handles missing return values.
/// @author Solmate (https://github.com/Rari-Capital/solmate/blob/main/src/utils/SafeTransferLib.sol)
/// @author Modified from Gnosis (https://github.com/gnosis/gp-v2-contracts/blob/main/src/contracts/libraries/GPv2SafeERC20.sol)
/// @dev Use with caution! Some functions in this library knowingly create dirty bits at the destination of the free memory pointer.
library SafeTransferLib {
    /*///////////////////////////////////////////////////////////////
                            ETH OPERATIONS
    //////////////////////////////////////////////////////////////*/

    function safeTransferETH(address to, uint256 amount) internal {
        bool callStatus;

        assembly {
            // Transfer the ETH and store if it succeeded or not.
            callStatus := call(gas(), to, amount, 0, 0, 0, 0)
        }

        require(callStatus, "ETH_TRANSFER_FAILED");
    }

    /*///////////////////////////////////////////////////////////////
                           ERC20 OPERATIONS
    //////////////////////////////////////////////////////////////*/

    function safeTransferFrom(
        ERC20 token,
        address from,
        address to,
        uint256 amount
    ) internal {
        bool callStatus;

        assembly {
            // Get a pointer to some free memory.
            let freeMemoryPointer := mload(0x40)

            // Write the abi-encoded calldata to memory piece by piece:
            mstore(freeMemoryPointer, 0x23b872dd00000000000000000000000000000000000000000000000000000000) // Begin with the function selector.
            mstore(add(freeMemoryPointer, 4), and(from, 0xffffffffffffffffffffffffffffffffffffffff)) // Mask and append the "from" argument.
            mstore(add(freeMemoryPointer, 36), and(to, 0xffffffffffffffffffffffffffffffffffffffff)) // Mask and append the "to" argument.
            mstore(add(freeMemoryPointer, 68), amount) // Finally append the "amount" argument. No mask as it's a full 32 byte value.

            // Call the token and store if it succeeded or not.
            // We use 100 because the calldata length is 4 + 32 * 3.
            callStatus := call(gas(), token, 0, freeMemoryPointer, 100, 0, 0)
        }

        require(didLastOptionalReturnCallSucceed(callStatus), "TRANSFER_FROM_FAILED");
    }

    function safeTransfer(
        ERC20 token,
        address to,
        uint256 amount
    ) internal {
        bool callStatus;

        assembly {
            // Get a pointer to some free memory.
            let freeMemoryPointer := mload(0x40)

            // Write the abi-encoded calldata to memory piece by piece:
            mstore(freeMemoryPointer, 0xa9059cbb00000000000000000000000000000000000000000000000000000000) // Begin with the function selector.
            mstore(add(freeMemoryPointer, 4), and(to, 0xffffffffffffffffffffffffffffffffffffffff)) // Mask and append the "to" argument.
            mstore(add(freeMemoryPointer, 36), amount) // Finally append the "amount" argument. No mask as it's a full 32 byte value.

            // Call the token and store if it succeeded or not.
            // We use 68 because the calldata length is 4 + 32 * 2.
            callStatus := call(gas(), token, 0, freeMemoryPointer, 68, 0, 0)
        }

        require(didLastOptionalReturnCallSucceed(callStatus), "TRANSFER_FAILED");
    }

    function safeApprove(
        ERC20 token,
        address to,
        uint256 amount
    ) internal {
        bool callStatus;

        assembly {
            // Get a pointer to some free memory.
            let freeMemoryPointer := mload(0x40)

            // Write the abi-encoded calldata to memory piece by piece:
            mstore(freeMemoryPointer, 0x095ea7b300000000000000000000000000000000000000000000000000000000) // Begin with the function selector.
            mstore(add(freeMemoryPointer, 4), and(to, 0xffffffffffffffffffffffffffffffffffffffff)) // Mask and append the "to" argument.
            mstore(add(freeMemoryPointer, 36), amount) // Finally append the "amount" argument. No mask as it's a full 32 byte value.

            // Call the token and store if it succeeded or not.
            // We use 68 because the calldata length is 4 + 32 * 2.
            callStatus := call(gas(), token, 0, freeMemoryPointer, 68, 0, 0)
        }

        require(didLastOptionalReturnCallSucceed(callStatus), "APPROVE_FAILED");
    }

    /*///////////////////////////////////////////////////////////////
                         INTERNAL HELPER LOGIC
    //////////////////////////////////////////////////////////////*/

    function didLastOptionalReturnCallSucceed(bool callStatus) private pure returns (bool success) {
        assembly {
            // Get how many bytes the call returned.
            let returnDataSize := returndatasize()

            // If the call reverted:
            if iszero(callStatus) {
                // Copy the revert message into memory.
                returndatacopy(0, 0, returnDataSize)

                // Revert with the same message.
                revert(0, returnDataSize)
            }

            switch returnDataSize
            case 32 {
                // Copy the return data into memory.
                returndatacopy(0, 0, returnDataSize)

                // Set success to whether it returned true.
                success := iszero(iszero(mload(0)))
            }
            case 0 {
                // There was no return data.
                success := 1
            }
            default {
                // It returned some malformed input.
                success := 0
            }
        }
    }
}

// SPDX-License-Identifier: AGPL-3.0-only
pragma solidity 0.8.11;

// External references
import { ERC20 } from "@rari-capital/solmate/src/tokens/ERC20.sol";

// Internal references
import { Trust } from "@sense-finance/v1-utils/src/Trust.sol";

/// @title Base Token
contract Token is ERC20, Trust {
    constructor(
        string memory _name,
        string memory _symbol,
        uint8 _decimals,
        address _trusted
    ) ERC20(_name, _symbol, _decimals) Trust(_trusted) {}

    /// @param usr The address to send the minted tokens
    /// @param amount The amount to be minted
    function mint(address usr, uint256 amount) public requiresTrust {
        _mint(usr, amount);
    }

    /// @param usr The address from where to burn tokens from
    /// @param amount The amount to be burned
    function burn(address usr, uint256 amount) public requiresTrust {
        _burn(usr, amount);
    }
}

// SPDX-License-Identifier: AGPL-3.0-only
pragma solidity >=0.7.0;

/// @notice Ultra minimal authorization logic for smart contracts.
/// @author From https://github.com/Rari-Capital/solmate/blob/fab107565a51674f3a3b5bfdaacc67f6179b1a9b/src/auth/Trust.sol
abstract contract Trust {
    event UserTrustUpdated(address indexed user, bool trusted);

    mapping(address => bool) public isTrusted;

    constructor(address initialUser) {
        isTrusted[initialUser] = true;

        emit UserTrustUpdated(initialUser, true);
    }

    function setIsTrusted(address user, bool trusted) public virtual requiresTrust {
        isTrusted[user] = trusted;

        emit UserTrustUpdated(user, trusted);
    }

    modifier requiresTrust() {
        require(isTrusted[msg.sender], "UNTRUSTED");

        _;
    }
}

// SPDX-License-Identifier: AGPL-3.0-only
pragma solidity 0.8.11;

// Internal references
import { Divider } from "../Divider.sol";
import { Token } from "./Token.sol";

/// @title Yield Token
/// @notice Strips off excess before every transfer
contract YT is Token {
    address public immutable adapter;
    address public immutable divider;
    uint256 public immutable maturity;

    constructor(
        address _adapter,
        uint256 _maturity,
        string memory _name,
        string memory _symbol,
        uint8 _decimals,
        address _divider
    ) Token(_name, _symbol, _decimals, _divider) {
        adapter = _adapter;
        maturity = _maturity;
        divider = _divider;
    }

    function collect() external returns (uint256 _collected) {
        return Divider(divider).collect(msg.sender, adapter, maturity, 0, address(0));
    }

    function transfer(address to, uint256 value) public override returns (bool) {
        Divider(divider).collect(msg.sender, adapter, maturity, value, to);
        return super.transfer(to, value);
    }

    function transferFrom(
        address from,
        address to,
        uint256 value
    ) public override returns (bool) {
        if (value > 0) Divider(divider).collect(from, adapter, maturity, value, to);
        return super.transferFrom(from, to, value);
    }
}

{
  "compilationTarget": {
    "@sense-finance/v1-core/src/tokens/YT.sol": "YT"
  },
  "evmVersion": "london",
  "libraries": {},
  "metadata": {
    "bytecodeHash": "ipfs",
    "useLiteralContent": true
  },
  "optimizer": {
    "enabled": true,
    "runs": 1500
  },
  "remappings": []
}