Lever interest bearing USDT

// SPDX-License-Identifier: agpl-3.0
pragma solidity 0.6.12;

/**
 * @dev Collection of functions related to the address type
 */
library Address {
  /**
   * @dev Returns true if `account` is a contract.
   *
   * [IMPORTANT]
   * ====
   * It is unsafe to assume that an address for which this function returns
   * false is an externally-owned account (EOA) and not a contract.
   *
   * Among others, `isContract` will return false for the following
   * types of addresses:
   *
   *  - an externally-owned account
   *  - a contract in construction
   *  - an address where a contract will be created
   *  - an address where a contract lived, but was destroyed
   * ====
   */
  function isContract(address account) internal view returns (bool) {
    // According to EIP-1052, 0x0 is the value returned for not-yet created accounts
    // and 0xc5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470 is returned
    // for accounts without code, i.e. `keccak256('')`
    bytes32 codehash;
    bytes32 accountHash = 0xc5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470;
    // solhint-disable-next-line no-inline-assembly
    assembly {
      codehash := extcodehash(account)
    }
    return (codehash != accountHash && codehash != 0x0);
  }

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

    // solhint-disable-next-line avoid-low-level-calls, avoid-call-value
    (bool success, ) = recipient.call{value: amount}('');
    require(success, 'Address: unable to send value, recipient may have reverted');
  }
}

// SPDX-License-Identifier: MIT
pragma solidity 0.6.12;

/*
 * @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 GSN 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 payable) {
    return msg.sender;
  }

  function _msgData() internal view virtual returns (bytes memory) {
    this; // silence state mutability warning without generating bytecode - see https://github.com/ethereum/solidity/issues/2691
    return msg.data;
  }
}

// SPDX-License-Identifier: agpl-3.0
pragma solidity 0.6.12;

library DataTypes {
  // refer to the whitepaper, section 1.1 basic concepts for a formal description of these properties.
  struct ReserveData {
    //stores the reserve configuration
    ReserveConfigurationMap configuration;
    //the liquidity index. Expressed in ray
    uint128 liquidityIndex;
    //variable borrow index. Expressed in ray
    uint128 variableBorrowIndex;
    //the current supply rate. Expressed in ray
    uint128 currentLiquidityRate;
    //the current variable borrow rate. Expressed in ray
    uint128 currentVariableBorrowRate;
    uint40 lastUpdateTimestamp;
    //tokens addresses
    address xTokenAddress;
    address variableDebtTokenAddress;
    //address of the interest rate strategy
    address interestRateStrategyAddress;
    //the id of the reserve. Represents the position in the list of the active reserves
    uint8 id;
  }

  struct ReserveConfigurationMap {
    //bit 0-15: LTV
    //bit 16-31: Liq. threshold
    //bit 32-47: Liq. bonus
    //bit 48-55: Decimals
    //bit 56: Reserve is active
    //bit 57: reserve is frozen
    //bit 58: borrowing is enabled
    //bit 60-63: reserved
    //bit 64-79: reserve factor
    uint256 data;
  }

  struct UserConfigurationMap {
    uint256 data;
  }

}

// SPDX-License-Identifier: agpl-3.0
pragma solidity 0.6.12;

/**
 * @title Errors library
 * @author Lever
 * @notice Defines the error messages emitted by the different contracts of the Lever protocol
 * @dev Error messages prefix glossary:
 *  - VL = ValidationLogic
 *  - MATH = Math libraries
 *  - CT = Common errors between tokens (XToken, VariableDebtToken)
 *  - XT = XToken
 *  - DT = VariableDebtToken
 *  - MP = MarginPool
 *  - MPAPR = MarginPoolAddressesProviderRegistry
 *  - MPC = MarginPoolConfiguration
 *  - RL = ReserveLogic
 *  - MPCM = MarginPoolCollateralManager
 *  - P = Pausable
 */
library Errors {
  //common errors
  string public constant CALLER_NOT_POOL_ADMIN = '33'; // 'The caller must be the pool admin'
  string public constant BORROW_ALLOWANCE_NOT_ENOUGH = '59'; // User borrows on behalf, but allowance are too small

  //contract specific errors
  string public constant VL_INVALID_AMOUNT = '1'; // 'Amount must be greater than 0'
  string public constant VL_NO_ACTIVE_RESERVE = '2'; // 'Action requires an active reserve'
  string public constant VL_RESERVE_FROZEN = '3'; // 'Action cannot be performed because the reserve is frozen'
  string public constant VL_CURRENT_AVAILABLE_LIQUIDITY_NOT_ENOUGH = '4'; // 'The current liquidity is not enough'
  string public constant VL_NOT_ENOUGH_AVAILABLE_USER_BALANCE = '5'; // 'User cannot withdraw more than the available balance'
  string public constant VL_TRANSFER_NOT_ALLOWED = '6'; // 'Transfer cannot be allowed.'
  string public constant VL_BORROWING_NOT_ENABLED = '7'; // 'Borrowing is not enabled'
  string public constant VL_INVALID_INTEREST_RATE_MODE_SELECTED = '8'; // 'Invalid interest rate mode selected'
  string public constant VL_COLLATERAL_BALANCE_IS_0 = '9'; // 'The collateral balance is 0'
  string public constant VL_HEALTH_FACTOR_LOWER_THAN_LIQUIDATION_THRESHOLD = '10'; // 'Health factor is lesser than the liquidation threshold'
  string public constant VL_COLLATERAL_CANNOT_COVER_NEW_BORROW = '11'; // 'There is not enough collateral to cover a new borrow'
  string public constant VL_COLLATERAL_SAME_AS_BORROWING_CURRENCY = '13'; // collateral is (mostly) the same currency that is being borrowed
  string public constant VL_NO_DEBT_OF_SELECTED_TYPE = '15'; // 'he needs to have variable debt'
  string public constant VL_NO_EXPLICIT_AMOUNT_TO_REPAY_ON_BEHALF = '16'; // 'To repay on behalf of an user an explicit amount to repay is needed'
  string public constant VL_NO_VARIABLE_RATE_LOAN_IN_RESERVE = '18'; // 'User does not have a variable rate loan in progress on this reserve'
  string public constant VL_UNDERLYING_BALANCE_NOT_GREATER_THAN_0 = '19'; // 'The underlying balance needs to be greater than 0'
  string public constant VL_DEPOSIT_ALREADY_IN_USE = '20'; // 'User deposit is already being used as collateral'
  string public constant MP_INTEREST_RATE_REBALANCE_CONDITIONS_NOT_MET = '22'; // 'Interest rate rebalance conditions were not met'
  string public constant MP_LIQUIDATION_CALL_FAILED = '23'; // 'Liquidation call failed'
  string public constant MP_NOT_ENOUGH_LIQUIDITY_TO_BORROW = '24'; // 'There is not enough liquidity available to borrow'
  string public constant MP_REQUESTED_AMOUNT_TOO_SMALL = '25'; // 'The requested amount is too small for a FlashLoan.'
  string public constant MP_INCONSISTENT_PROTOCOL_ACTUAL_BALANCE = '26'; // 'The actual balance of the protocol is inconsistent'
  string public constant MP_CALLER_NOT_MARGIN_POOL_CONFIGURATOR = '27'; // 'The caller of the function is not the margin pool configurator'
  string public constant MP_INCONSISTENT_FLASHLOAN_PARAMS = '28';
  string public constant CT_CALLER_MUST_BE_MARGIN_POOL = '29'; // 'The caller of this function must be a margin pool'
  string public constant CT_CANNOT_GIVE_ALLOWANCE_TO_HIMSELF = '30'; // 'User cannot give allowance to himself'
  string public constant CT_TRANSFER_AMOUNT_NOT_GT_0 = '31'; // 'Transferred amount needs to be greater than zero'
  string public constant RL_RESERVE_ALREADY_INITIALIZED = '32'; // 'Reserve has already been initialized'
  string public constant MPC_RESERVE_LIQUIDITY_NOT_0 = '34'; // 'The liquidity of the reserve needs to be 0'
  string public constant MPC_INVALID_XTOKEN_POOL_ADDRESS = '35'; // 'The liquidity of the reserve needs to be 0'
  string public constant MPC_INVALID_VARIABLE_DEBT_TOKEN_POOL_ADDRESS = '37'; // 'The liquidity of the reserve needs to be 0'
  string public constant MPC_INVALID_VARIABLE_DEBT_TOKEN_UNDERLYING_ADDRESS = '39'; // 'The liquidity of the reserve needs to be 0'
  string public constant MPC_INVALID_ADDRESSES_PROVIDER_ID = '40'; // 'The liquidity of the reserve needs to be 0'
  string public constant MPC_INVALID_CONFIGURATION = '75'; // 'Invalid risk parameters for the reserve'
  string public constant MPC_CALLER_NOT_EMERGENCY_ADMIN = '76'; // 'The caller must be the emergency admin'
  string public constant MPAPR_PROVIDER_NOT_REGISTERED = '41'; // 'Provider is not registered'
  string public constant MPCM_HEALTH_FACTOR_NOT_BELOW_THRESHOLD = '42'; // 'Health factor is not below the threshold'
  string public constant MPCM_COLLATERAL_CANNOT_BE_LIQUIDATED = '43'; // 'The collateral chosen cannot be liquidated'
  string public constant MPCM_SPECIFIED_CURRENCY_NOT_BORROWED_BY_USER = '44'; // 'User did not borrow the specified currency'
  string public constant MPCM_NOT_ENOUGH_LIQUIDITY_TO_LIQUIDATE = '45'; // "There isn't enough liquidity available to liquidate"
  string public constant MPCM_NO_ERRORS = '46'; // 'No errors'
  string public constant MP_INVALID_FLASHLOAN_MODE = '47'; //Invalid flashloan mode selected
  string public constant MATH_MULTIPLICATION_OVERFLOW = '48';
  string public constant MATH_ADDITION_OVERFLOW = '49';
  string public constant MATH_DIVISION_BY_ZERO = '50';
  string public constant RL_LIQUIDITY_INDEX_OVERFLOW = '51'; //  Liquidity index overflows uint128
  string public constant RL_VARIABLE_BORROW_INDEX_OVERFLOW = '52'; //  Variable borrow index overflows uint128
  string public constant RL_LIQUIDITY_RATE_OVERFLOW = '53'; //  Liquidity rate overflows uint128
  string public constant RL_VARIABLE_BORROW_RATE_OVERFLOW = '54'; //  Variable borrow rate overflows uint128
  string public constant CT_INVALID_MINT_AMOUNT = '56'; //invalid amount to mint
  string public constant MP_FAILED_REPAY_WITH_COLLATERAL = '57';
  string public constant CT_INVALID_BURN_AMOUNT = '58'; //invalid amount to burn
  string public constant MP_FAILED_COLLATERAL_SWAP = '60';
  string public constant MP_INVALID_EQUAL_ASSETS_TO_SWAP = '61';
  string public constant MP_REENTRANCY_NOT_ALLOWED = '62';
  string public constant MP_CALLER_MUST_BE_AN_XTOKEN = '63';
  string public constant MP_IS_PAUSED = '64'; // 'Pool is paused'
  string public constant MP_NO_MORE_RESERVES_ALLOWED = '65';
  string public constant MP_INVALID_FLASH_LOAN_EXECUTOR_RETURN = '66';
  string public constant RC_INVALID_LTV = '67';
  string public constant RC_INVALID_LIQ_THRESHOLD = '68';
  string public constant RC_INVALID_LIQ_BONUS = '69';
  string public constant RC_INVALID_DECIMALS = '70';
  string public constant RC_INVALID_RESERVE_FACTOR = '71';
  string public constant MPAPR_INVALID_ADDRESSES_PROVIDER_ID = '72';
  string public constant VL_INCONSISTENT_FLASHLOAN_PARAMS = '73';
  string public constant MP_INCONSISTENT_PARAMS_LENGTH = '74';
  string public constant UL_INVALID_INDEX = '77';
  string public constant MP_NOT_CONTRACT = '78';
  string public constant SDT_BURN_EXCEEDS_BALANCE = '80';

  enum CollateralManagerErrors {
    NO_ERROR,
    NO_COLLATERAL_AVAILABLE,
    COLLATERAL_CANNOT_BE_LIQUIDATED,
    CURRRENCY_NOT_BORROWED,
    HEALTH_FACTOR_ABOVE_THRESHOLD,
    NOT_ENOUGH_LIQUIDITY,
    NO_ACTIVE_RESERVE,
    HEALTH_FACTOR_LOWER_THAN_LIQUIDATION_THRESHOLD,
    INVALID_EQUAL_ASSETS_TO_SWAP,
    FROZEN_RESERVE
  }
}

// SPDX-License-Identifier: agpl-3.0
pragma solidity 0.6.12;

/**
 * @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);
}

// SPDX-License-Identifier: agpl-3.0
pragma solidity 0.6.12;

import {IERC20} from './IERC20.sol';

interface IERC20Detailed is IERC20 {
  function name() external view returns (string memory);

  function symbol() external view returns (string memory);

  function decimals() external view returns (uint8);
}

// SPDX-License-Identifier: agpl-3.0
pragma solidity 0.6.12;
pragma experimental ABIEncoderV2;

import {IMarginPoolAddressesProvider} from './IMarginPoolAddressesProvider.sol';
import {DataTypes} from './DataTypes.sol';

interface IMarginPool {
  /**
   * @dev Emitted on deposit()
   * @param reserve The address of the underlying asset of the reserve
   * @param user The address initiating the deposit
   * @param onBehalfOf The beneficiary of the deposit, receiving the xTokens
   * @param amount The amount deposited
   **/
  event Deposit(
    address indexed reserve,
    address indexed user,
    address indexed onBehalfOf,
    uint256 amount
  );

  /**
   * @dev Emitted on withdraw()
   * @param reserve The address of the underlyng asset being withdrawn
   * @param user The address initiating the withdrawal, owner of xTokens
   * @param to Address that will receive the underlying
   * @param amount The amount to be withdrawn
   **/
  event Withdraw(address indexed reserve, address indexed user, address indexed to, uint256 amount);

  /**
   * @dev Emitted on borrow() when debt needs to be opened
   * @param reserve The address of the underlying asset being borrowed
   * @param user The address of the user initiating the borrow(), receiving the funds on borrow()
   * @param onBehalfOf The address that will be getting the debt
   * @param amount The amount borrowed out
   * @param borrowRate The numeric rate at which the user has borrowed
   **/
  event Borrow(
    address indexed reserve,
    address indexed user,
    address indexed onBehalfOf,
    uint256 amount,
    uint256 borrowRate
  );

  /**
   * @dev Emitted on repay()
   * @param reserve The address of the underlying asset of the reserve
   * @param user The beneficiary of the repayment, getting his debt reduced
   * @param repayer The address of the user initiating the repay(), providing the funds
   * @param amount The amount repaid
   **/
  event Repay(
    address indexed reserve,
    address indexed user,
    address indexed repayer,
    uint256 amount
  );
  
    /**
   * @dev Emitted on swapTokensForTokens() swapTokensForClosePosition() swapWithAggregation() closeWithAggregation()
   * @param user The address initiating the swap
   * @param srcReserve The address of the underlying asset of the source reserve
   * @param dstReserve The address of the underlying asset of the destination reserve
   * @param srcAmount The amount of source reserve
   * @param dstAmount The amount of destination reserve
   **/
  event Swap(
    address indexed user,
    address indexed srcReserve,
    address indexed dstReserve,
    uint256 srcAmount,
    uint256 dstAmount
  );


  /**
   * @dev Emitted on setUserUseReserveAsCollateral()
   * @param reserve The address of the underlying asset of the reserve
   * @param user The address of the user enabling the usage as collateral
   **/
  event ReserveUsedAsCollateralEnabled(address indexed reserve, address indexed user);

  /**
   * @dev Emitted on setUserUseReserveAsCollateral()
   * @param reserve The address of the underlying asset of the reserve
   * @param user The address of the user enabling the usage as collateral
   **/
  event ReserveUsedAsCollateralDisabled(address indexed reserve, address indexed user);


  /**
   * @dev Emitted when the pause is triggered.
   */
  event Paused();

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

  /**
    * @dev Emitted when a borrower is liquidated. This event is emitted by the MarginPool via
    * MarginPoolCollateral manager using a DELEGATECALL
    * This allows to have the events in the generated ABI for MarginPool.
    * @param collateralAsset The address of the underlying asset used as collateral, to receive as result of the liquidation
    * @param debtAsset The address of the underlying borrowed asset to be repaid with the liquidation
    * @param user The address of the borrower getting liquidated
    * @param debtToCover The debt amount of borrowed `asset` the liquidator wants to cover
    * @param liquidatedCollateralAmount The amount of collateral received by the liiquidator
    * @param liquidator The address of the liquidator
    **/
  event LiquidationCall(
      address indexed collateralAsset,
      address indexed debtAsset,
      address indexed user,
      uint256 debtToCover,
      uint256 liquidatedCollateralAmount,
      address liquidator
  );

  /**
   * @dev Emitted when the state of a reserve is updated. NOTE: This event is actually declared
   * in the ReserveLogic library and emitted in the updateInterestRates() function. Since the function is internal,
   * the event will actually be fired by the MarginPool contract. The event is therefore replicated here so it
   * gets added to the MarginPool ABI
   * @param reserve The address of the underlying asset of the reserve
   * @param liquidityRate The new liquidity rate
   * @param variableBorrowRate The new variable borrow rate
   * @param liquidityIndex The new liquidity index
   * @param variableBorrowIndex The new variable borrow index
   **/
  event ReserveDataUpdated(
    address indexed reserve,
    uint256 liquidityRate,
    uint256 variableBorrowRate,
    uint256 liquidityIndex,
    uint256 variableBorrowIndex
  );

  /**
   * @dev Deposits an `amount` of underlying asset into the reserve, receiving in return overlying xTokens.
   * - E.g. User deposits 100 USDC and gets in return 100 xUSDC
   * @param asset The address of the underlying asset to deposit
   * @param amount The amount to be deposited
   * @param onBehalfOf The address that will receive the xTokens, same as msg.sender if the user
   *   wants to receive them on his own wallet, or a different address if the beneficiary of xTokens
   *   is a different wallet
   **/
  function deposit(
    address asset,
    uint256 amount,
    address onBehalfOf
  ) external;

  /**
   * @dev Withdraws an `amount` of underlying asset from the reserve, burning the equivalent xTokens owned
   * E.g. User has 100 xUSDC, calls withdraw() and receives 100 USDC, burning the 100 xUSDC
   * @param asset The address of the underlying asset to withdraw
   * @param amount The underlying amount to be withdrawn
   *   - Send the value type(uint256).max in order to withdraw the whole xToken balance
   * @param to Address that will receive the underlying, same as msg.sender if the user
   *   wants to receive it on his own wallet, or a different address if the beneficiary is a
   *   different wallet
   * @return The final amount withdrawn
   **/
  function withdraw(
    address asset,
    uint256 amount,
    address to
  ) external returns (uint256);

  /**
   * @dev Allows users to borrow a specific `amount` of the reserve underlying asset, provided that the borrower
   * already deposited enough collateral, or he was given enough allowance by a credit delegator on the
   * corresponding debt token ( VariableDebtToken)
   * - E.g. User borrows 100 USDC passing as `onBehalfOf` his own address, receiving the 100 USDC in his wallet
   *   and 100 variable debt tokens
   * @param asset The address of the underlying asset to borrow
   * @param amount The amount to be borrowed
   * @param onBehalfOf Address of the user who will receive the debt. Should be the address of the borrower itself
   * calling the function if he wants to borrow against his own collateral, or the address of the credit delegator
   * if he has been given credit delegation allowance
   **/
  function borrow(
    address asset,
    uint256 amount,
    address onBehalfOf
  ) external;

  /**
   * @notice Repays a borrowed `amount` on a specific reserve, burning the equivalent debt tokens owned
   * - E.g. User repays 100 USDC, burning 100 variable debt tokens of the `onBehalfOf` address
   * @param asset The address of the borrowed underlying asset previously borrowed
   * @param amount The amount to repay
   * - Send the value type(uint256).max in order to repay the whole debt for `asset` on the specific `debtMode`
   * @param onBehalfOf Address of the user who will get his debt reduced/removed. Should be the address of the
   * user calling the function if he wants to reduce/remove his own debt, or the address of any other
   * other borrower whose debt should be removed
   * @return The final amount repaid
   **/
  function repay(
    address asset,
    uint256 amount,
    address onBehalfOf
  ) external returns (uint256);

  function swapTokensForTokens(
    uint256 amountIn,
    uint256 amountOut,
    address[] calldata path,
    bool isExactIn,
    bool isUni
  ) external;

  function swapTokensForClosePosition(
        uint256 amountIn,
        uint256 amountOut,
        address[] calldata path,
        bool isExactIn,
        bool isUni
  ) external;

  /**
   * @dev Allows depositors to enable/disable a specific deposited asset as collateral
   * @param asset The address of the underlying asset deposited
   * @param useAsCollateral `true` if the user wants to use the deposit as collateral, `false` otherwise
   **/
  function setUserUseReserveAsCollateral(address asset, bool useAsCollateral) external;

  /**
   * @dev Function to liquidate a non-healthy position collateral-wise, with Health Factor below 1
   * - The caller (liquidator) covers `debtToCover` amount of debt of the user getting liquidated, and receives
   *   a proportionally amount of the `collateralAsset` plus a bonus to cover market risk
   * @param collateralAsset The address of the underlying asset used as collateral, to receive as result of the liquidation
   * @param debtAsset The address of the underlying borrowed asset to be repaid with the liquidation
   * @param user The address of the borrower getting liquidated
   * @param debtToCover The debt amount of borrowed `asset` the liquidator wants to cover
   **/
  function liquidationCall(
    address collateralAsset,
    address debtAsset,
    address user,
    uint256 debtToCover
  ) external;

  /**
   * @dev Returns the user account data across all the reserves
   * @param user The address of the user
   * @return totalCollateralETH the total collateral in ETH of the user
   * @return totalDebtETH the total debt in ETH of the user
   * @return availableBorrowsETH the borrowing power left of the user
   * @return currentLiquidationThreshold the liquidation threshold of the user
   * @return ltv the loan to value of the user
   * @return healthFactor the current health factor of the user
   **/
  function getUserAccountData(address user)
    external
    view
    returns (
      uint256 totalCollateralETH,
      uint256 totalDebtETH,
      uint256 availableBorrowsETH,
      uint256 currentLiquidationThreshold,
      uint256 ltv,
      uint256 healthFactor
    );

  function initReserve(
    address reserve,
    address xTokenAddress,
    address variableDebtAddress,
    address interestRateStrategyAddress
  ) external;

  function setReserveInterestRateStrategyAddress(address reserve, address rateStrategyAddress)
    external;

  function setConfiguration(address reserve, uint256 configuration) external;

  /**
   * @dev Returns the configuration of the reserve
   * @param asset The address of the underlying asset of the reserve
   * @return The configuration of the reserve
   **/
  function getConfiguration(address asset)
    external
    view
    returns (DataTypes.ReserveConfigurationMap memory);

  /**
   * @dev Returns the configuration of the user across all the reserves
   * @param user The user address
   * @return The configuration of the user
   **/
  function getUserConfiguration(address user)
    external
    view
    returns (DataTypes.UserConfigurationMap memory);

  /**
   * @dev Returns the normalized income normalized income of the reserve
   * @param asset The address of the underlying asset of the reserve
   * @return The reserve's normalized income
   */
  function getReserveNormalizedIncome(address asset) external view returns (uint256);

  /**
   * @dev Returns the normalized variable debt per unit of asset
   * @param asset The address of the underlying asset of the reserve
   * @return The reserve normalized variable debt
   */
  function getReserveNormalizedVariableDebt(address asset) external view returns (uint256);

  /**
   * @dev Returns the state and configuration of the reserve
   * @param asset The address of the underlying asset of the reserve
   * @return The state of the reserve
   **/
  function getReserveData(address asset) external view returns (DataTypes.ReserveData memory);

  function finalizeTransfer(
    address asset,
    address from,
    address to,
    uint256 amount,
    uint256 balanceFromAfter,
    uint256 balanceToBefore
  ) external;

  function getReservesList() external view returns (address[] memory);

  function getAddressesProvider() external view returns (IMarginPoolAddressesProvider);

  function setPause(bool val) external;

  function paused() external view returns (bool);
}

// SPDX-License-Identifier: agpl-3.0
pragma solidity 0.6.12;

/**
 * @title MarginPoolAddressesProvider contract
 * @dev Main registry of addresses part of or connected to the protocol, including permissioned roles
 * - Acting also as factory of proxies and admin of those, so with right to change its implementations
 * - Owned by the Lever Governance
 * @author Lever
 **/
interface IMarginPoolAddressesProvider {
  event MarginPoolUpdated(address indexed newAddress);
  event ConfigurationAdminUpdated(address indexed newAddress);
  event EmergencyAdminUpdated(address indexed newAddress);
  event MarginPoolConfiguratorUpdated(address indexed newAddress);
  event MarginPoolCollateralManagerUpdated(address indexed newAddress);
  event PriceOracleUpdated(address indexed newAddress);
  event ProxyCreated(bytes32 id, address indexed newAddress);
  event AddressSet(bytes32 id, address indexed newAddress, bool hasProxy);
  event LeverTokenUpdated(address indexed newAddress);
  event TreasuryAddressUpdated(address indexed newAddress);
  event RewardsDistributionUpdated(address indexed newAddress);
  event OrderBookUpdated(address indexed newAddress);
  event SwapMinerUpdated(address indexed newAddress);


  function setAddress(bytes32 id, address newAddress) external;

  function setAddressAsProxy(bytes32 id, address impl) external;

  function getAddress(bytes32 id) external view returns (address);

  function getMarginPool() external view returns (address);

  function setMarginPoolImpl(address pool, address UniswapRouter,address SushiswapRouter, address weth) external;

  function getMarginPoolConfigurator() external view returns (address);

  function setMarginPoolConfiguratorImpl(address configurator) external;

  function getPoolAdmin() external view returns (address);

  function setPoolAdmin(address admin) external;

  function getEmergencyAdmin() external view returns (address);

  function setEmergencyAdmin(address admin) external;

  function getPriceOracle() external view returns (address);

  function setPriceOracle(address priceOracle) external;

  function getLeverToken() external view returns (address);

  function setLeverToken(address lever) external;

  function getTreasuryAddress() external view returns (address);

  function setTreasuryAddress(address treasuryAddress) external;

  function getRewardsDistribution() external view returns (address);

  function setRewardsDistribution(address rewardsDistribution) external;

  function getOrderBook() external view returns (address);

  function setOrderBookImpl(address addressProvider, address UniswapRouter, address weth) external;

  function getSwapMiner() external view returns (address);

  function setSwapMinerImpl(address _swapMiner, address UniswapRouter, address _uniswapLevPairToken, address LeverUsdOracle) external;
}

// SPDX-License-Identifier: agpl-3.0
pragma solidity 0.6.12;

interface IScaledBalanceToken {
  /**
   * @dev Returns the scaled balance of the user. The scaled balance is the sum of all the
   * updated stored balance divided by the reserve's liquidity index at the moment of the update
   * @param user The user whose balance is calculated
   * @return The scaled balance of the user
   **/
  function scaledBalanceOf(address user) external view returns (uint256);

  /**
   * @dev Returns the scaled balance of the user and the scaled total supply.
   * @param user The address of the user
   * @return The scaled balance of the user
   * @return The scaled balance and the scaled total supply
   **/
  function getScaledUserBalanceAndSupply(address user) external view returns (uint256, uint256);

  /**
   * @dev Returns the scaled total supply of the variable debt token. Represents sum(debt/index)
   * @return The scaled total supply
   **/
  function scaledTotalSupply() external view returns (uint256);
}

// SPDX-License-Identifier: agpl-3.0
pragma solidity 0.6.12;

import {IERC20} from './IERC20.sol';
import {IScaledBalanceToken} from './IScaledBalanceToken.sol';

interface IXToken is IERC20, IScaledBalanceToken {
  /**
   * @dev Emitted after the mint action
   * @param from The address performing the mint
   * @param value The amount being
   * @param index The new liquidity index of the reserve
   **/
  event Mint(address indexed from, uint256 value, uint256 index);

  /**
   * @dev Mints `amount` xTokens to `user`
   * @param user The address receiving the minted tokens
   * @param amount The amount of tokens getting minted
   * @param index The new liquidity index of the reserve
   * @return `true` if the the previous balance of the user was 0
   */
  function mint(
    address user,
    uint256 amount,
    uint256 index
  ) external returns (bool);

  /**
   * @dev Emitted after xTokens are burned
   * @param from The owner of the xTokens, getting them burned
   * @param target The address that will receive the underlying
   * @param value The amount being burned
   * @param index The new liquidity index of the reserve
   **/
  event Burn(address indexed from, address indexed target, uint256 value, uint256 index);

  /**
   * @dev Emitted during the transfer action
   * @param from The user whose tokens are being transferred
   * @param to The recipient
   * @param value The amount being transferred
   * @param index The new liquidity index of the reserve
   **/
  event BalanceTransfer(address indexed from, address indexed to, uint256 value, uint256 index);

  /**
   * @dev Burns xTokens from `user` and sends the equivalent amount of underlying to `receiverOfUnderlying`
   * @param user The owner of the xTokens, getting them burned
   * @param receiverOfUnderlying The address that will receive the underlying
   * @param amount The amount being burned
   * @param index The new liquidity index of the reserve
   **/
  function burn(
    address user,
    address receiverOfUnderlying,
    uint256 amount,
    uint256 index
  ) external;

  /**
   * @dev Mints xTokens to the reserve treasury
   * @param amount The amount of tokens getting minted
   * @param index The new liquidity index of the reserve
   */
  function mintToTreasury(uint256 amount, uint256 index) external;

  /**
   * @dev Transfers xTokens in the event of a borrow being liquidated, in case the liquidators reclaims the xToken
   * @param from The address getting liquidated, current owner of the xTokens
   * @param to The recipient
   * @param value The amount of tokens getting transferred
   **/
  function transferOnLiquidation(
    address from,
    address to,
    uint256 value
  ) external;

  /**
   * @dev Transfers the underlying asset to `target`. Used by the MarginPool to transfer
   * assets in borrow(), withdraw() and flashLoan()
   * @param user The recipient of the xTokens
   * @param amount The amount getting transferred
   * @return The amount transferred
   **/
  function transferUnderlyingTo(address user, uint256 amount) external returns (uint256);
}

// SPDX-License-Identifier: agpl-3.0
pragma solidity 0.6.12;

import {Context} from './Context.sol';
import {IERC20} from './IERC20.sol';
import {IERC20Detailed} from './IERC20Detailed.sol';
import {SafeMath} from './SafeMath.sol';

/**
 * @title ERC20
 * @notice Basic ERC20 implementation
 * @author Lever, inspired by the Openzeppelin ERC20 implementation
 **/
contract IncentivizedERC20 is Context, IERC20, IERC20Detailed {
  using SafeMath for uint256;


  mapping(address => uint256) internal _balances;

  mapping(address => mapping(address => uint256)) private _allowances;
  uint256 internal _totalSupply;
  string private _name;
  string private _symbol;
  uint8 private _decimals;

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

  /**
   * @return The name of the token
   **/
  function name() public view override returns (string memory) {
    return _name;
  }

  /**
   * @return The symbol of the token
   **/
  function symbol() public view override returns (string memory) {
    return _symbol;
  }

  /**
   * @return The decimals of the token
   **/
  function decimals() public view override returns (uint8) {
    return _decimals;
  }

  /**
   * @return The total supply of the token
   **/
  function totalSupply() public view virtual override returns (uint256) {
    return _totalSupply;
  }

  /**
   * @return The balance of the token
   **/
  function balanceOf(address account) public view virtual override returns (uint256) {
    return _balances[account];
  }

  /**
   * @dev Executes a transfer of tokens from _msgSender() to recipient
   * @param recipient The recipient of the tokens
   * @param amount The amount of tokens being transferred
   * @return `true` if the transfer succeeds, `false` otherwise
   **/
  function transfer(address recipient, uint256 amount) public virtual override returns (bool) {
    _transfer(_msgSender(), recipient, amount);
    emit Transfer(_msgSender(), recipient, amount);
    return true;
  }

  /**
   * @dev Returns the allowance of spender on the tokens owned by owner
   * @param owner The owner of the tokens
   * @param spender The user allowed to spend the owner's tokens
   * @return The amount of owner's tokens spender is allowed to spend
   **/
  function allowance(address owner, address spender)
    public
    view
    virtual
    override
    returns (uint256)
  {
    return _allowances[owner][spender];
  }

  /**
   * @dev Allows `spender` to spend the tokens owned by _msgSender()
   * @param spender The user allowed to spend _msgSender() tokens
   * @return `true`
   **/
  function approve(address spender, uint256 amount) public virtual override returns (bool) {
    _approve(_msgSender(), spender, amount);
    return true;
  }

  /**
   * @dev Executes a transfer of token from sender to recipient, if _msgSender() is allowed to do so
   * @param sender The owner of the tokens
   * @param recipient The recipient of the tokens
   * @param amount The amount of tokens being transferred
   * @return `true` if the transfer succeeds, `false` otherwise
   **/
  function transferFrom(
    address sender,
    address recipient,
    uint256 amount
  ) public virtual override returns (bool) {
    _transfer(sender, recipient, amount);
    _approve(
      sender,
      _msgSender(),
      _allowances[sender][_msgSender()].sub(amount, 'ERC20: transfer amount exceeds allowance')
    );
    emit Transfer(sender, recipient, amount);
    return true;
  }

  /**
   * @dev Increases the allowance of spender to spend _msgSender() tokens
   * @param spender The user allowed to spend on behalf of _msgSender()
   * @param addedValue The amount being added to the allowance
   * @return `true`
   **/
  function increaseAllowance(address spender, uint256 addedValue) public virtual returns (bool) {
    _approve(_msgSender(), spender, _allowances[_msgSender()][spender].add(addedValue));
    return true;
  }

  /**
   * @dev Decreases the allowance of spender to spend _msgSender() tokens
   * @param spender The user allowed to spend on behalf of _msgSender()
   * @param subtractedValue The amount being subtracted to the allowance
   * @return `true`
   **/
  function decreaseAllowance(address spender, uint256 subtractedValue)
    public
    virtual
    returns (bool)
  {
    _approve(
      _msgSender(),
      spender,
      _allowances[_msgSender()][spender].sub(
        subtractedValue,
        'ERC20: decreased allowance below zero'
      )
    );
    return true;
  }

  function _transfer(
    address sender,
    address recipient,
    uint256 amount
  ) internal virtual {
    require(sender != address(0), 'ERC20: transfer from the zero address');
    require(recipient != address(0), 'ERC20: transfer to the zero address');

    _beforeTokenTransfer(sender, recipient, amount);

    uint256 oldSenderBalance = _balances[sender];
    _balances[sender] = oldSenderBalance.sub(amount, 'ERC20: transfer amount exceeds balance');
    _balances[recipient] = _balances[recipient].add(amount);

  }

  function _mint(address account, uint256 amount) internal virtual {
    require(account != address(0), 'ERC20: mint to the zero address');

    _beforeTokenTransfer(address(0), account, amount);

    uint256 oldTotalSupply = _totalSupply;
    _totalSupply = oldTotalSupply.add(amount);

    uint256 oldAccountBalance = _balances[account];
    _balances[account] = oldAccountBalance.add(amount);
  }

  function _burn(address account, uint256 amount) internal virtual {
    require(account != address(0), 'ERC20: burn from the zero address');

    _beforeTokenTransfer(account, address(0), amount);

    uint256 oldTotalSupply = _totalSupply;
    _totalSupply = oldTotalSupply.sub(amount);

    uint256 oldAccountBalance = _balances[account];
    _balances[account] = oldAccountBalance.sub(amount, 'ERC20: burn amount exceeds balance');

  }

  function _approve(
    address owner,
    address spender,
    uint256 amount
  ) internal virtual {
    require(owner != address(0), 'ERC20: approve from the zero address');
    require(spender != address(0), 'ERC20: approve to the zero address');

    _allowances[owner][spender] = amount;
    emit Approval(owner, spender, amount);
  }

  function _setName(string memory newName) internal {
    _name = newName;
  }

  function _setSymbol(string memory newSymbol) internal {
    _symbol = newSymbol;
  }

  function _setDecimals(uint8 newDecimals) internal {
    _decimals = newDecimals;
  }

  function _beforeTokenTransfer(
    address from,
    address to,
    uint256 amount
  ) internal virtual {}
}

// SPDX-License-Identifier: MIT

pragma solidity 0.6.12;

import {IERC20} from './IERC20.sol';
import {SafeMath} from './SafeMath.sol';
import {Address} from './Address.sol';

/**
 * @title SafeERC20
 * @dev Wrappers around ERC20 operations that throw on failure (when the token
 * contract returns false). Tokens that return no value (and instead revert or
 * throw on failure) are also supported, non-reverting calls are assumed to be
 * successful.
 * To use this library you can add a `using SafeERC20 for IERC20;` statement to your contract,
 * which allows you to call the safe operations as `token.safeTransfer(...)`, etc.
 */
library SafeERC20 {
  using SafeMath for uint256;
  using Address for address;

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

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

  function safeApprove(
    IERC20 token,
    address spender,
    uint256 value
  ) internal {
    require(
      (value == 0) || (token.allowance(address(this), spender) == 0),
      'SafeERC20: approve from non-zero to non-zero allowance'
    );
    callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, value));
  }

  function callOptionalReturn(IERC20 token, bytes memory data) private {
    require(address(token).isContract(), 'SafeERC20: call to non-contract');

    // solhint-disable-next-line avoid-low-level-calls
    (bool success, bytes memory returndata) = address(token).call(data);
    require(success, 'SafeERC20: low-level call failed');

    if (returndata.length > 0) {
      // Return data is optional
      // solhint-disable-next-line max-line-length
      require(abi.decode(returndata, (bool)), 'SafeERC20: ERC20 operation did not succeed');
    }
  }
}

// SPDX-License-Identifier: agpl-3.0
pragma solidity 0.6.12;

/**
 * @dev Wrappers over Solidity's arithmetic operations with added overflow
 * checks.
 *
 * Arithmetic operations in Solidity wrap on overflow. This can easily result
 * in bugs, because programmers usually assume that an overflow raises an
 * error, which is the standard behavior in high level programming languages.
 * `SafeMath` restores this intuition by reverting the transaction when 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.
 */
library SafeMath {
  /**
   * @dev Returns the addition of two unsigned integers, reverting on
   * overflow.
   *
   * Counterpart to Solidity's `+` operator.
   *
   * Requirements:
   * - Addition cannot overflow.
   */
  function add(uint256 a, uint256 b) internal pure returns (uint256) {
    uint256 c = a + b;
    require(c >= a, 'SafeMath: addition overflow');

    return c;
  }

  /**
   * @dev Returns the subtraction of two unsigned integers, reverting on
   * overflow (when the result is negative).
   *
   * Counterpart to Solidity's `-` operator.
   *
   * Requirements:
   * - Subtraction cannot overflow.
   */
  function sub(uint256 a, uint256 b) internal pure returns (uint256) {
    return sub(a, b, 'SafeMath: subtraction overflow');
  }

  /**
   * @dev Returns the subtraction of two unsigned integers, reverting with custom message on
   * overflow (when the result is negative).
   *
   * Counterpart to Solidity's `-` operator.
   *
   * Requirements:
   * - Subtraction cannot overflow.
   */
  function sub(
    uint256 a,
    uint256 b,
    string memory errorMessage
  ) internal pure returns (uint256) {
    require(b <= a, errorMessage);
    uint256 c = a - b;

    return c;
  }

  /**
   * @dev Returns the multiplication of two unsigned integers, reverting on
   * overflow.
   *
   * Counterpart to Solidity's `*` operator.
   *
   * Requirements:
   * - Multiplication cannot overflow.
   */
  function mul(uint256 a, uint256 b) internal pure returns (uint256) {
    // Gas optimization: this is cheaper than requiring 'a' not being zero, but the
    // benefit is lost if 'b' is also tested.
    // See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522
    if (a == 0) {
      return 0;
    }

    uint256 c = a * b;
    require(c / a == b, 'SafeMath: multiplication overflow');

    return c;
  }

  /**
   * @dev Returns the integer division of two unsigned integers. Reverts on
   * division by zero. The result is rounded towards zero.
   *
   * Counterpart to Solidity's `/` operator. Note: this function uses a
   * `revert` opcode (which leaves remaining gas untouched) while Solidity
   * uses an invalid opcode to revert (consuming all remaining gas).
   *
   * Requirements:
   * - The divisor cannot be zero.
   */
  function div(uint256 a, uint256 b) internal pure returns (uint256) {
    return div(a, b, 'SafeMath: division by zero');
  }

  /**
   * @dev Returns the integer division of two unsigned integers. Reverts with custom message on
   * division by zero. The result is rounded towards zero.
   *
   * Counterpart to Solidity's `/` operator. Note: this function uses a
   * `revert` opcode (which leaves remaining gas untouched) while Solidity
   * uses an invalid opcode to revert (consuming all remaining gas).
   *
   * Requirements:
   * - The divisor cannot be zero.
   */
  function div(
    uint256 a,
    uint256 b,
    string memory errorMessage
  ) internal pure returns (uint256) {
    // Solidity only automatically asserts when dividing by 0
    require(b > 0, errorMessage);
    uint256 c = a / b;
    // assert(a == b * c + a % b); // There is no case in which this doesn't hold

    return c;
  }

  /**
   * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
   * Reverts when dividing by zero.
   *
   * Counterpart to Solidity's `%` operator. This function uses a `revert`
   * opcode (which leaves remaining gas untouched) while Solidity uses an
   * invalid opcode to revert (consuming all remaining gas).
   *
   * Requirements:
   * - The divisor cannot be zero.
   */
  function mod(uint256 a, uint256 b) internal pure returns (uint256) {
    return mod(a, b, 'SafeMath: modulo by zero');
  }

  /**
   * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
   * Reverts with custom message when dividing by zero.
   *
   * Counterpart to Solidity's `%` operator. This function uses a `revert`
   * opcode (which leaves remaining gas untouched) while Solidity uses an
   * invalid opcode to revert (consuming all remaining gas).
   *
   * Requirements:
   * - The divisor cannot be zero.
   */
  function mod(
    uint256 a,
    uint256 b,
    string memory errorMessage
  ) internal pure returns (uint256) {
    require(b != 0, errorMessage);
    return a % b;
  }
}

// SPDX-License-Identifier: agpl-3.0
pragma solidity 0.6.12;

import {Errors} from './Errors.sol';

/**
 * @title WadRayMath library
 * @author Lever
 * @dev Provides mul and div function for wads (decimal numbers with 18 digits precision) and rays (decimals with 27 digits)
 **/

library WadRayMath {
  uint256 internal constant WAD = 1e18;
  uint256 internal constant halfWAD = WAD / 2;

  uint256 internal constant RAY = 1e27;
  uint256 internal constant halfRAY = RAY / 2;

  uint256 internal constant WAD_RAY_RATIO = 1e9;

  /**
   * @return One ray, 1e27
   **/
  function ray() internal pure returns (uint256) {
    return RAY;
  }

  /**
   * @return One wad, 1e18
   **/

  function wad() internal pure returns (uint256) {
    return WAD;
  }

  /**
   * @return Half ray, 1e27/2
   **/
  function halfRay() internal pure returns (uint256) {
    return halfRAY;
  }

  /**
   * @return Half ray, 1e18/2
   **/
  function halfWad() internal pure returns (uint256) {
    return halfWAD;
  }

  /**
   * @dev Multiplies two wad, rounding half up to the nearest wad
   * @param a Wad
   * @param b Wad
   * @return The result of a*b, in wad
   **/
  function wadMul(uint256 a, uint256 b) internal pure returns (uint256) {
    if (a == 0 || b == 0) {
      return 0;
    }

    require(a <= (type(uint256).max - halfWAD) / b, Errors.MATH_MULTIPLICATION_OVERFLOW);

    return (a * b + halfWAD) / WAD;
  }

  /**
   * @dev Divides two wad, rounding half up to the nearest wad
   * @param a Wad
   * @param b Wad
   * @return The result of a/b, in wad
   **/
  function wadDiv(uint256 a, uint256 b) internal pure returns (uint256) {
    require(b != 0, Errors.MATH_DIVISION_BY_ZERO);
    uint256 halfB = b / 2;

    require(a <= (type(uint256).max - halfB) / WAD, Errors.MATH_MULTIPLICATION_OVERFLOW);

    return (a * WAD + halfB) / b;
  }

  /**
   * @dev Multiplies two ray, rounding half up to the nearest ray
   * @param a Ray
   * @param b Ray
   * @return The result of a*b, in ray
   **/
  function rayMul(uint256 a, uint256 b) internal pure returns (uint256) {
    if (a == 0 || b == 0) {
      return 0;
    }

    require(a <= (type(uint256).max - halfRAY) / b, Errors.MATH_MULTIPLICATION_OVERFLOW);

    return (a * b + halfRAY) / RAY;
  }

  /**
   * @dev Divides two ray, rounding half up to the nearest ray
   * @param a Ray
   * @param b Ray
   * @return The result of a/b, in ray
   **/
  function rayDiv(uint256 a, uint256 b) internal pure returns (uint256) {
    require(b != 0, Errors.MATH_DIVISION_BY_ZERO);
    uint256 halfB = b / 2;

    require(a <= (type(uint256).max - halfB) / RAY, Errors.MATH_MULTIPLICATION_OVERFLOW);

    return (a * RAY + halfB) / b;
  }

  /**
   * @dev Casts ray down to wad
   * @param a Ray
   * @return a casted to wad, rounded half up to the nearest wad
   **/
  function rayToWad(uint256 a) internal pure returns (uint256) {
    uint256 halfRatio = WAD_RAY_RATIO / 2;
    uint256 result = halfRatio + a;
    require(result >= halfRatio, Errors.MATH_ADDITION_OVERFLOW);

    return result / WAD_RAY_RATIO;
  }

  /**
   * @dev Converts wad up to ray
   * @param a Wad
   * @return a converted in ray
   **/
  function wadToRay(uint256 a) internal pure returns (uint256) {
    uint256 result = a * WAD_RAY_RATIO;
    require(result / WAD_RAY_RATIO == a, Errors.MATH_MULTIPLICATION_OVERFLOW);
    return result;
  }
}

// SPDX-License-Identifier: agpl-3.0
pragma solidity 0.6.12;

import {IERC20} from "./IERC20.sol";
import {SafeERC20} from "./SafeERC20.sol";
import {IMarginPool} from "./IMarginPool.sol";
import {IXToken} from "./IXToken.sol";
import {WadRayMath} from "./WadRayMath.sol";
import {Errors} from "./Errors.sol";
import {IncentivizedERC20} from "./IncentivizedERC20.sol";
import {SafeMath} from "./SafeMath.sol";
import {
    IMarginPoolAddressesProvider
} from "./IMarginPoolAddressesProvider.sol";
import {Address} from "./Address.sol";

/**
 * @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, so we distribute
        return (a / 2) + (b / 2) + (((a % 2) + (b % 2)) / 2);
    }
}

/**
 * @dev Contract module that helps prevent reentrant calls to a function.
 *
 * Inheriting from `ReentrancyGuard` will make the `nonReentrant` modifier
 * available, which can be aplied to functions to make sure there are no nested
 * (reentrant) calls to them.
 *
 * Note that because there is a single `nonReentrant` guard, functions marked as
 * `nonReentrant` may not call one another. This can be worked around by making
 * those functions `private`, and then adding `external` `nonReentrant` entry
 * points to them.
 */
contract ReentrancyGuard {
    /// @dev counter to allow mutex lock with only one SSTORE operation
    uint256 private _guardCounter;

    constructor() internal {
        // The counter starts at one to prevent changing it from zero to a non-zero
        // value, which is a more expensive operation.
        _guardCounter = 1;
    }

    /**
     * @dev Prevents a contract from calling itself, directly or indirectly.
     * Calling a `nonReentrant` function from another `nonReentrant`
     * function is not supported. It is possible to prevent this from happening
     * by making the `nonReentrant` function external, and make it call a
     * `private` function that does the actual work.
     */
    modifier nonReentrant() {
        _guardCounter += 1;
        uint256 localCounter = _guardCounter;
        _;
        require(
            localCounter == _guardCounter,
            "ReentrancyGuard: reentrant call"
        );
    }
}

/**
 * @title Lever ERC20 XToken
 * @dev Implementation of the interest bearing token for the Lever protocol
 * @author Lever
 */
contract XToken is
    IncentivizedERC20,
    IXToken,
    ReentrancyGuard
{
    using WadRayMath for uint256;
    using SafeERC20 for IERC20;
    // address public rewardsDistribution;
    IERC20 public rewardsToken;
    uint256 public periodFinish = 0;
    uint256 public rewardRate = 0;
    uint256 public rewardsDuration = 30 days;
    uint256 public lastUpdateTime;
    uint256 public rewardPerTokenStored;

    mapping(address => uint256) public userRewardPerTokenPaid;
    mapping(address => uint256) public rewards;

    bytes public constant EIP712_REVISION = bytes("1");
    bytes32 internal constant EIP712_DOMAIN =
        keccak256(
            "EIP712Domain(string name,string version,uint256 chainId,address verifyingContract)"
        );
    bytes32 public constant PERMIT_TYPEHASH =
        keccak256(
            "Permit(address owner,address spender,uint256 value,uint256 nonce,uint256 deadline)"
        );

    uint256 public constant UINT_MAX_VALUE = uint256(-1);
    address public immutable UNDERLYING_ASSET_ADDRESS;
    address public immutable RESERVE_TREASURY_ADDRESS;
    IMarginPool public immutable POOL;
    IMarginPoolAddressesProvider public addressesProvider;

    /// @dev owner => next valid nonce to submit with permit()
    mapping(address => uint256) public _nonces;

    bytes32 public DOMAIN_SEPARATOR;

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

    modifier updateReward(address account) {
        rewardPerTokenStored = rewardPerToken();
        lastUpdateTime = lastTimeRewardApplicable();
        if (account != address(0)) {
            rewards[account] = earned(account);
            userRewardPerTokenPaid[account] = rewardPerTokenStored;
        }
        _;
    }

    modifier onlyRewardsDistribution() {
        require(
            msg.sender == addressesProvider.getRewardsDistribution(),
            "Caller is not RewardsDistribution contract"
        );
        _;
    }

    modifier onlyMarginPool {
        require(
            _msgSender() == address(POOL),
            Errors.CT_CALLER_MUST_BE_MARGIN_POOL
        );
        _;
    }

    constructor(
        address _addressesProvider,
        address underlyingAssetAddress,
        string memory tokenName,
        string memory tokenSymbol,
        uint8 decimals
    ) public IncentivizedERC20(tokenName, tokenSymbol, decimals) {
        addressesProvider = IMarginPoolAddressesProvider(_addressesProvider);
        POOL = IMarginPool(addressesProvider.getMarginPool());
        UNDERLYING_ASSET_ADDRESS = underlyingAssetAddress;
        RESERVE_TREASURY_ADDRESS = addressesProvider.getTreasuryAddress();
        // rewardsDistribution = addressesProvider.getRewardsDistribution();
        rewardsToken = IERC20(IMarginPoolAddressesProvider(_addressesProvider).getLeverToken());
    }

    /**
     * @dev Burns xTokens from `user` and sends the equivalent amount of underlying to `receiverOfUnderlying`
     * - Only callable by the MarginPool, as extra state updates there need to be managed
     * @param user The owner of the xTokens, getting them burned
     * @param receiverOfUnderlying The address that will receive the underlying
     * @param amount The amount being burned
     * @param index The new liquidity index of the reserve
     **/
    function burn(
        address user,
        address receiverOfUnderlying,
        uint256 amount,
        uint256 index
    ) external override onlyMarginPool updateReward(user) {
        uint256 amountScaled = amount.rayDiv(index);
        require(amountScaled != 0, Errors.CT_INVALID_BURN_AMOUNT);
        _burn(user, amountScaled);
        if (receiverOfUnderlying != address(this)) {
            IERC20(UNDERLYING_ASSET_ADDRESS).safeTransfer(
                receiverOfUnderlying,
                amount
            );
        }

        emit Transfer(user, address(0), amount);
        emit Burn(user, receiverOfUnderlying, amount, index);
    }

    /**
     * @dev Mints `amount` xTokens to `user`
     * - Only callable by the MarginPool, as extra state updates there need to be managed
     * @param user The address receiving the minted tokens
     * @param amount The amount of tokens getting minted
     * @param index The new liquidity index of the reserve
     * @return `true` if the the previous balance of the user was 0
     */
    function mint(
        address user,
        uint256 amount,
        uint256 index
    ) external override onlyMarginPool updateReward(user) returns (bool) {
        uint256 previousBalance = super.balanceOf(user);

        uint256 amountScaled = amount.rayDiv(index);
        require(amountScaled != 0, Errors.CT_INVALID_MINT_AMOUNT);
        _mint(user, amountScaled);
        emit Transfer(address(0), user, amount);
        emit Mint(user, amount, index);

        return previousBalance == 0;
    }

    /**
     * @dev Mints xTokens to the reserve treasury
     * - Only callable by the MarginPool
     * @param amount The amount of tokens getting minted
     * @param index The new liquidity index of the reserve
     */
    function mintToTreasury(uint256 amount, uint256 index)
        external
        override
        onlyMarginPool
        updateReward(RESERVE_TREASURY_ADDRESS)
    {
        if (amount == 0) {
            return;
        }

        // Compared to the normal mint, we don't check for rounding errors.
        // The amount to mint can easily be very small since it is a fraction of the interest ccrued.
        // In that case, the treasury will experience a (very small) loss, but it
        // wont cause potentially valid transactions to fail.
        _mint(RESERVE_TREASURY_ADDRESS, amount.rayDiv(index));
        emit Transfer(address(0), RESERVE_TREASURY_ADDRESS, amount);
        emit Mint(RESERVE_TREASURY_ADDRESS, amount, index);
    }

    /**
     * @dev Transfers xTokens in the event of a borrow being liquidated, in case the liquidators reclaims the xToken
     * - Only callable by the MarginPool
     * @param from The address getting liquidated, current owner of the xTokens
     * @param to The recipient
     * @param value The amount of tokens getting transferred
     **/
    function transferOnLiquidation(
        address from,
        address to,
        uint256 value
    ) external override onlyMarginPool updateReward(from) updateReward(to) {
        // Being a normal transfer, the Transfer() and BalanceTransfer() are emitted
        // so no need to emit a specific event here
        _transfer(from, to, value, false);
        emit Transfer(from, to, value);
    }

    /**
     * @dev Calculates the balance of the user: principal balance + interest generated by the principal
     * @param user The user whose balance is calculated
     * @return The balance of the user
     **/
    function balanceOf(address user)
        public
        view
        override(IncentivizedERC20, IERC20)
        returns (uint256)
    {
        return
            super.balanceOf(user).rayMul(
                POOL.getReserveNormalizedIncome(UNDERLYING_ASSET_ADDRESS)
            );
    }

    /**
     * @dev Returns the scaled balance of the user. The scaled balance is the sum of all the
     * updated stored balance divided by the reserve's liquidity index at the moment of the update
     * @param user The user whose balance is calculated
     * @return The scaled balance of the user
     **/
    function scaledBalanceOf(address user)
        external
        view
        override
        returns (uint256)
    {
        return super.balanceOf(user);
    }

    /**
     * @dev Returns the scaled balance of the user and the scaled total supply.
     * @param user The address of the user
     * @return The scaled balance of the user
     * @return The scaled balance and the scaled total supply
     **/
    function getScaledUserBalanceAndSupply(address user)
        external
        view
        override
        returns (uint256, uint256)
    {
        return (super.balanceOf(user), super.totalSupply());
    }

    /**
     * @dev calculates the total supply of the specific xToken
     * since the balance of every single user increases over time, the total supply
     * does that too.
     * @return the current total supply
     **/
    function totalSupply()
        public
        view
        override(IncentivizedERC20, IERC20)
        returns (uint256)
    {
        uint256 currentSupplyScaled = super.totalSupply();

        if (currentSupplyScaled == 0) {
            return 0;
        }

        return
            currentSupplyScaled.rayMul(
                POOL.getReserveNormalizedIncome(UNDERLYING_ASSET_ADDRESS)
            );
    }

    /**
     * @dev Returns the scaled total supply of the variable debt token. Represents sum(debt/index)
     * @return the scaled total supply
     **/
    function scaledTotalSupply()
        public
        view
        virtual
        override
        returns (uint256)
    {
        return super.totalSupply();
    }

    /**
     * @dev Transfers the underlying asset to `target`. Used by the MarginPool to transfer
     * assets in borrow(), withdraw()
     * @param target The recipient of the xTokens
     * @param amount The amount getting transferred
     * @return The amount transferred
     **/
    function transferUnderlyingTo(address target, uint256 amount)
        external
        override
        onlyMarginPool
        returns (uint256)
    {
        IERC20(UNDERLYING_ASSET_ADDRESS).safeTransfer(target, amount);
        return amount;
    }

    /**
     * @dev implements the permit function as for
     * https://github.com/ethereum/EIPs/blob/8a34d644aacf0f9f8f00815307fd7dd5da07655f/EIPS/eip-2612.md
     * @param owner The owner of the funds
     * @param spender The spender
     * @param value The amount
     * @param deadline The deadline timestamp, type(uint256).max for max deadline
     * @param v Signature param
     * @param s Signature param
     * @param r Signature param
     */
    function permit(
        address owner,
        address spender,
        uint256 value,
        uint256 deadline,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) external {
        require(owner != address(0), "INVALID_OWNER");
        //solium-disable-next-line
        require(block.timestamp <= deadline, "INVALID_EXPIRATION");
        uint256 currentValidNonce = _nonces[owner];
        bytes32 digest =
            keccak256(
                abi.encodePacked(
                    "\x19\x01",
                    DOMAIN_SEPARATOR,
                    keccak256(
                        abi.encode(
                            PERMIT_TYPEHASH,
                            owner,
                            spender,
                            value,
                            currentValidNonce,
                            deadline
                        )
                    )
                )
            );
        require(owner == ecrecover(digest, v, r, s), "INVALID_SIGNATURE");
        _nonces[owner] = currentValidNonce.add(1);
        _approve(owner, spender, value);
    }

    /**
     * @dev Transfers the xTokens between two users. Validates the transfer
     * (ie checks for valid HF after the transfer) if required
     * @param from The source address
     * @param to The destination address
     * @param amount The amount getting transferred
     * @param validate `true` if the transfer needs to be validated
     **/
    function _transfer(
        address from,
        address to,
        uint256 amount,
        bool validate
    ) internal updateReward(from) updateReward(to) {
        uint256 index =
            POOL.getReserveNormalizedIncome(UNDERLYING_ASSET_ADDRESS);

        uint256 fromBalanceBefore = super.balanceOf(from).rayMul(index);
        uint256 toBalanceBefore = super.balanceOf(to).rayMul(index);

        super._transfer(from, to, amount.rayDiv(index));
        if (validate) {
            POOL.finalizeTransfer(
                UNDERLYING_ASSET_ADDRESS,
                from,
                to,
                amount,
                fromBalanceBefore,
                toBalanceBefore
            );
        }

        emit BalanceTransfer(from, to, amount, index);
    }

    /**
     * @dev Overrides the parent _transfer to force validated transfer() and transferFrom()
     * @param from The source address
     * @param to The destination address
     * @param amount The amount getting transferred
     **/
    function _transfer(
        address from,
        address to,
        uint256 amount
    ) internal override {
        _transfer(from, to, amount, true);
    }

    function lastTimeRewardApplicable() public view returns (uint256) {
        return Math.min(block.timestamp, periodFinish);
    }

    function rewardPerToken() public view returns (uint256) {
        if (totalSupply() == 0) {
            return rewardPerTokenStored;
        }
        return
            rewardPerTokenStored.add(
                lastTimeRewardApplicable()
                    .sub(lastUpdateTime)
                    .mul(rewardRate)
                    .mul(1e18)
                    .div(totalSupply())
            );
    }

    function earned(address account) public view returns (uint256) {
        return
            balanceOf(account)
                .mul(rewardPerToken().sub(userRewardPerTokenPaid[account]))
                .div(1e18)
                .add(rewards[account]);
    }

    function getRewardForDuration() external view returns (uint256) {
        return rewardRate.mul(rewardsDuration);
    }

    function getReward() public nonReentrant updateReward(msg.sender) {
        uint256 reward = rewards[msg.sender];
        require(reward > 0);
        rewards[msg.sender] = 0;
        rewardsToken.safeTransfer(msg.sender, reward);
        emit RewardPaid(msg.sender, reward);
    }

    /* ========== RESTRICTED FUNCTIONS ========== */

    function notifyRewardAmount(uint256 reward, uint256 _rewardsDuration)
        external
        onlyRewardsDistribution
        updateReward(address(0))
    {
        // Ensure the provided reward amount is not more than the balance in the contract.
        // This keeps the reward rate in the right range, preventing overflows due to
        // very high values of rewardRate in the earned and rewardsPerToken functions;
        // Reward + leftover must be less than 2^256 / 10^18 to avoid overflow.
        uint256 balance = rewardsToken.balanceOf(address(this));
        if (block.timestamp >= periodFinish) {
            rewardsDuration = _rewardsDuration;
            rewardRate = reward.div(rewardsDuration);
            require(
                rewardRate <= balance.div(rewardsDuration),
                "Provided reward too high"
            );
            periodFinish = block.timestamp.add(rewardsDuration);
        } else {
            uint256 remaining = periodFinish.sub(block.timestamp);
            uint256 leftover = remaining.mul(rewardRate);
            rewardRate = reward.add(leftover).div(remaining);
            require(
                rewardRate <= balance.div(remaining),
                "Provided reward too high"
            );
        }

        lastUpdateTime = block.timestamp;
        emit RewardAdded(reward, _rewardsDuration);
    }

    /* ========== EVENTS ========== */

    event RewardAdded(uint256 reward, uint256 _rewardsDuration);
    event RewardPaid(address indexed user, uint256 reward);
}

{
  "compilationTarget": {
    "XToken.sol": "XToken"
  },
  "evmVersion": "istanbul",
  "libraries": {},
  "metadata": {
    "bytecodeHash": "ipfs"
  },
  "optimizer": {
    "enabled": true,
    "runs": 200
  },
  "remappings": []
}