// File: contracts/protocol/vault/ethereum/ConvexVault/ConvexCurveLPVault.sol



// SPDX-License-Identifier: agpl-3.0
pragma solidity ^0.8.0;
pragma experimental ABIEncoderV2;

import {IncentiveVault} from '../../IncentiveVault.sol';
import {IERC20} from '../../../../dependencies/openzeppelin/contracts/IERC20.sol';
import {SafeERC20} from '../../../../dependencies/openzeppelin/contracts/SafeERC20.sol';
import {IERC20Detailed} from '../../../../dependencies/openzeppelin/contracts/IERC20Detailed.sol';
import {IConvexBooster} from '../../../../interfaces/IConvexBooster.sol';
import {IConvexBaseRewardPool} from '../../../../interfaces/IConvexBaseRewardPool.sol';
import {Errors} from '../../../libraries/helpers/Errors.sol';
import {SturdyInternalAsset} from '../../../tokenization/SturdyInternalAsset.sol';
import {PercentageMath} from '../../../libraries/math/PercentageMath.sol';
import {DataTypes} from '../../../libraries/types/DataTypes.sol';
import {ILendingPool} from '../../../../interfaces/ILendingPool.sol';

interface IRewards {
  function rewardToken() external view returns (address);
}

/**
 * @title ConvexCurveLPVault
 * @notice Curve LP Token Vault by using Convex on Ethereum
 * @author Sturdy
 **/
contract ConvexCurveLPVault is IncentiveVault {
  using SafeERC20 for IERC20;
  using PercentageMath for uint256;

  address public convexBooster;
  address internal curveLPToken;
  address internal internalAssetToken;
  uint256 internal convexPoolId;

  uint256 internal _incentiveRatio;

  /**
   * @dev Emitted on setConfiguration()
   * @param _curveLpToken The address of Curve LP Token
   * @param _convexPoolId The convex pool Id
   * @param _internalToken The address of internal asset
   */
  event SetParameters(address _curveLpToken, uint256 _convexPoolId, address _internalToken);

  /**
   * @dev The function to set parameters related to convex/curve
   * @param _lpToken The address of Curve LP Token which will be used in vault
   * @param _poolId  The convex pool Id for Curve LP Token
   */
  function setConfiguration(address _lpToken, uint256 _poolId) external payable onlyAdmin {
    require(_lpToken != address(0), Errors.VT_INVALID_CONFIGURATION);
    require(internalAssetToken == address(0), Errors.VT_INVALID_CONFIGURATION);

    convexBooster = 0xF403C135812408BFbE8713b5A23a04b3D48AAE31;
    curveLPToken = _lpToken;
    convexPoolId = _poolId;
    SturdyInternalAsset _interalToken = new SturdyInternalAsset(
      string(abi.encodePacked('Sturdy ', IERC20Detailed(_lpToken).symbol())),
      string(abi.encodePacked('c', IERC20Detailed(_lpToken).symbol())),
      IERC20Detailed(_lpToken).decimals()
    );
    internalAssetToken = address(_interalToken);

    emit SetParameters(_lpToken, _poolId, internalAssetToken);
  }

  /**
   * @dev The function to get internal asset address
   */
  function getInternalAsset() external view returns (address) {
    return internalAssetToken;
  }

  /**
   * @dev The function to get rewards token address
   */
  function getBaseRewardPool() internal view returns (address) {
    IConvexBooster.PoolInfo memory poolInfo = IConvexBooster(convexBooster).poolInfo(convexPoolId);
    return poolInfo.crvRewards;
  }

  /**
   * @dev The function to send rewards to YieldManager & Treasury
   * @param _asset The rewards token address
   */
  function _transferYield(address _asset) internal {
    require(_asset != address(0), Errors.VT_PROCESS_YIELD_INVALID);
    uint256 yieldAmount = IERC20(_asset).balanceOf(address(this));

    // Some ERC20 do not allow zero amounts to be sent:
    if (yieldAmount == 0) return;

    uint256 incentiveAmount;
    uint256 fee = _incentiveRatio;
    bool isIncentiveToken = (getIncentiveToken() == _asset);
    if (isIncentiveToken && fee != 0) {
      incentiveAmount = yieldAmount.percentMul(fee);
      _sendIncentive(incentiveAmount);
    }

    // Move some yield to treasury
    fee = _vaultFee;
    if (fee != 0) {
      uint256 treasuryAmount = yieldAmount.percentMul(fee);
      IERC20(_asset).safeTransfer(_treasuryAddress, treasuryAmount);
      yieldAmount -= treasuryAmount;
    }

    if (incentiveAmount > 0) {
      yieldAmount -= incentiveAmount;
    }

    // transfer to yieldManager
    if (yieldAmount > 0) {
      address yieldManager = _addressesProvider.getAddress('YIELD_MANAGER');
      IERC20(_asset).safeTransfer(yieldManager, yieldAmount);
    }

    emit ProcessYield(_asset, yieldAmount);
  }

  function processYield() external override {
    // Claim Rewards(CRV, CVX, Extra incentive tokens)
    address baseRewardPool = getBaseRewardPool();
    IConvexBaseRewardPool(baseRewardPool).getReward();

    // Transfer CRV to YieldManager
    _transferYield(IConvexBaseRewardPool(baseRewardPool).rewardToken());

    // Transfer CVX to YieldManager
    _transferYield(IConvexBooster(convexBooster).minter());
  }

  /**
   * @dev The function to transfer extra incentive token to YieldManager
   * @param _offset extraRewards start offset.
   * @param _count extraRewards count
   */
  function processExtraYield(uint256 _offset, uint256 _count) external payable onlyAdmin {
    address baseRewardPool = getBaseRewardPool();
    uint256 extraRewardsLength = IConvexBaseRewardPool(baseRewardPool).extraRewardsLength();

    require(_offset + _count <= extraRewardsLength, Errors.VT_EXTRA_REWARDS_INDEX_INVALID);

    for (uint256 i; i < _count; ++i) {
      address _extraReward = IConvexBaseRewardPool(baseRewardPool).extraRewards(_offset + i);
      address _rewardToken = IRewards(_extraReward).rewardToken();
      _transferYield(_rewardToken);
    }
  }

  /**
   * @dev Get yield amount based on strategy
   */
  function getYieldAmount() external view returns (uint256) {
    return _getYieldAmount(internalAssetToken);
  }

  /**
   * @dev Get price per share based on yield strategy
   */
  function pricePerShare() external view override returns (uint256) {
    uint256 decimals = IERC20Detailed(internalAssetToken).decimals();
    return 10**decimals;
  }

  /**
   * @dev Deposit to yield pool based on strategy and mint internal asset
   */
  function _depositToYieldPool(address _asset, uint256 _amount)
    internal
    override
    returns (address, uint256)
  {
    // receive Curve LP Token from user
    address token = curveLPToken;
    require(_asset == token, Errors.VT_COLLATERAL_DEPOSIT_INVALID);
    IERC20(token).safeTransferFrom(msg.sender, address(this), _amount);

    // deposit Curve LP Token to Convex
    address convexVault = convexBooster;
    IERC20(token).safeApprove(convexVault, 0);
    IERC20(token).safeApprove(convexVault, _amount);
    IConvexBooster(convexVault).deposit(convexPoolId, _amount, true);

    // mint
    address internalAsset = internalAssetToken;
    address lendingPoolAddress = _addressesProvider.getLendingPool();
    SturdyInternalAsset(internalAsset).mint(address(this), _amount);
    IERC20(internalAsset).safeApprove(lendingPoolAddress, 0);
    IERC20(internalAsset).safeApprove(lendingPoolAddress, _amount);

    return (internalAsset, _amount);
  }

  /**
   * @dev Get Withdrawal amount of Curve LP Token based on strategy
   */
  function _getWithdrawalAmount(address _asset, uint256 _amount)
    internal
    view
    override
    returns (address, uint256)
  {
    require(_asset == curveLPToken, Errors.VT_COLLATERAL_WITHDRAW_INVALID);

    // In this vault, return same amount of asset.
    return (internalAssetToken, _amount);
  }

  function _withdraw(uint256 _amount, address _to) internal returns (uint256) {
    // Withdraw from Convex
    address baseRewardPool = getBaseRewardPool();
    IConvexBaseRewardPool(baseRewardPool).withdrawAndUnwrap(_amount, false);

    // Deliver Curve LP Token
    IERC20(curveLPToken).safeTransfer(_to, _amount);

    // Burn
    SturdyInternalAsset(internalAssetToken).burn(address(this), _amount);

    return _amount;
  }

  function withdrawOnLiquidation(address _asset, uint256 _amount)
    external
    override
    returns (uint256)
  {
    require(_asset == curveLPToken, Errors.LP_LIQUIDATION_CALL_FAILED);
    require(msg.sender == _addressesProvider.getLendingPool(), Errors.LP_LIQUIDATION_CALL_FAILED);

    return _withdraw(_amount, msg.sender);
  }

  /**
   * @dev Withdraw from yield pool based on strategy and deliver asset
   */
  function _withdrawFromYieldPool(
    address,
    uint256 _amount,
    address _to
  ) internal override returns (uint256) {
    return _withdraw(_amount, _to);
  }

  function getIncentiveToken() public view override returns (address) {
    address baseRewardPool = getBaseRewardPool();
    return IConvexBaseRewardPool(baseRewardPool).rewardToken();
  }

  function getCurrentTotalIncentiveAmount() external view override returns (uint256) {
    if (_incentiveRatio > 0) {
      address baseRewardPool = getBaseRewardPool();
      uint256 earned = IConvexBaseRewardPool(baseRewardPool).earned(address(this));
      return earned.percentMul(_incentiveRatio);
    }
    return 0;
  }

  function getIncentiveRatio() external view override returns (uint256) {
    return _incentiveRatio;
  }

  function setIncentiveRatio(uint256 _ratio) external override onlyAdmin {
    require(_vaultFee + _ratio <= PercentageMath.PERCENTAGE_FACTOR, Errors.VT_FEE_TOO_BIG);

    // Get all available rewards & Send it to YieldDistributor,
    // so that the changing ratio does not affect asset's cumulative index
    if (_incentiveRatio != 0) {
      _clearRewards();
    }

    _incentiveRatio = _ratio;

    emit SetIncentiveRatio(_ratio);
  }

  function _getAToken() internal view override returns (address) {
    address internalAsset = internalAssetToken;
    DataTypes.ReserveData memory reserveData = ILendingPool(_addressesProvider.getLendingPool())
      .getReserveData(internalAsset);
    return reserveData.aTokenAddress;
  }

  function _clearRewards() internal override {
    address baseRewardPool = getBaseRewardPool();
    IConvexBaseRewardPool(baseRewardPool).getReward();
    _transferYield(IConvexBaseRewardPool(baseRewardPool).rewardToken());
  }
}

// File: contracts/protocol/vault/IncentiveVault.sol



// SPDX-License-Identifier: agpl-3.0
pragma solidity ^0.8.0;

import {GeneralVault} from './GeneralVault.sol';
import {IERC20} from '../../dependencies/openzeppelin/contracts/IERC20.sol';
import {SafeERC20} from '../../dependencies/openzeppelin/contracts/SafeERC20.sol';
import {Errors} from '../libraries/helpers/Errors.sol';
import {VariableYieldDistribution} from '../../incentives/VariableYieldDistribution.sol';

/**
 * @title GeneralVault
 * @notice Basic feature of vault
 * @author Sturdy
 **/

abstract contract IncentiveVault is GeneralVault {
  using SafeERC20 for IERC20;

  event SetIncentiveRatio(uint256 ratio);

  /**
   * @dev Get the incentive token address supported on this vault
   */
  function getIncentiveToken() public view virtual returns (address);

  /**
   * @dev Get current total incentive amount
   */
  function getCurrentTotalIncentiveAmount() external view virtual returns (uint256);

  /**
   * @dev Get Incentive Ratio
   */
  function getIncentiveRatio() external view virtual returns (uint256);

  /**
   * @dev Set Incentive Ratio
   */
  function setIncentiveRatio(uint256 _ratio) external virtual;

  /**
   * @dev Get AToken address for the vault
   */
  function _getAToken() internal view virtual returns (address);

  /**
   * @dev Claim all rewards and send some to YieldDistributor
   */
  function _clearRewards() internal virtual;

  /**
   * @dev Send incentive to YieldDistribution
   */
  function _sendIncentive(uint256 amount) internal {
    address asset = _getAToken();
    address incentiveToken = getIncentiveToken();

    // transfer to YieldDistributor
    address yieldDistributor = _addressesProvider.getAddress('VR_YIELD_DISTRIBUTOR');
    IERC20(incentiveToken).safeTransfer(yieldDistributor, amount);

    // notify to YieldDistributor so that it updates asset index
    VariableYieldDistribution(yieldDistributor).receivedRewards(asset, incentiveToken, amount);
  }
}

// File: contracts/dependencies/openzeppelin/contracts/IERC20.sol



// SPDX-License-Identifier: agpl-3.0
pragma solidity ^0.8.0;

/**
 * @dev Interface of the ERC20 standard as defined in the EIP.
 */
interface IERC20 {
  /**
   * @dev Returns the amount of tokens in existence.
   */
  function totalSupply() external view returns (uint256);

  /**
   * @dev Returns the amount of tokens owned by `account`.
   */
  function balanceOf(address account) external view returns (uint256);

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

  /**
   * @dev Returns the remaining number of tokens that `spender` will be
   * allowed to spend on behalf of `owner` through {transferFrom}. This is
   * zero by default.
   *
   * This value changes when {approve} or {transferFrom} are called.
   */
  function allowance(address owner, address spender) external view returns (uint256);

  /**
   * @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
   *
   * Returns a boolean value indicating whether the operation succeeded.
   *
   * IMPORTANT: Beware that changing an allowance with this method brings the risk
   * that someone may use both the old and the new allowance by unfortunate
   * transaction ordering. One possible solution to mitigate this race
   * condition is to first reduce the spender's allowance to 0 and set the
   * desired value afterwards:
   * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
   *
   * Emits an {Approval} event.
   */
  function approve(address spender, uint256 amount) external returns (bool);

  /**
   * @dev Moves `amount` tokens from `sender` to `recipient` using the
   * allowance mechanism. `amount` is then deducted from the caller's
   * allowance.
   *
   * Returns a boolean value indicating whether the operation succeeded.
   *
   * Emits a {Transfer} event.
   */
  function transferFrom(
    address sender,
    address recipient,
    uint256 amount
  ) external returns (bool);

  /**
   * @dev Emitted when `value` tokens are moved from one account (`from`) to
   * another (`to`).
   *
   * Note that `value` may be zero.
   */
  event Transfer(address indexed from, address indexed to, uint256 value);

  /**
   * @dev Emitted when the allowance of a `spender` for an `owner` is set by
   * a call to {approve}. `value` is the new allowance.
   */
  event Approval(address indexed owner, address indexed spender, uint256 value);
}

// File: contracts/dependencies/openzeppelin/contracts/SafeERC20.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

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

// File: contracts/dependencies/openzeppelin/contracts/IERC20Detailed.sol



// SPDX-License-Identifier: agpl-3.0
pragma solidity ^0.8.0;

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);
}

// File: contracts/interfaces/IConvexBooster.sol



// SPDX-License-Identifier: agpl-3.0
pragma solidity ^0.8.0;
pragma experimental ABIEncoderV2;

interface IConvexBooster {
  struct PoolInfo {
    address lptoken;
    address token;
    address gauge;
    address crvRewards;
    address stash;
    bool shutdown;
  }

  function minter() external view returns (address);

  function poolInfo(uint256 _poolId) external view returns (PoolInfo memory);

  function poolLength() external view returns (uint256);

  //deposit lp tokens and stake
  function deposit(
    uint256 _pid,
    uint256 _amount,
    bool _stake
  ) external returns (bool);

  //withdraw lp tokens
  function withdraw(uint256 _pid, uint256 _amount) external returns (bool);
}

// File: contracts/interfaces/IConvexBaseRewardPool.sol



// SPDX-License-Identifier: agpl-3.0
pragma solidity ^0.8.0;

interface IConvexBaseRewardPool {
  function earned(address account) external view returns (uint256);

  function withdrawAndUnwrap(uint256 amount, bool claim) external;

  function getReward(address _account, bool _claimExtras) external;

  function getReward() external;

  function rewardToken() external view returns (address);

  function extraRewardsLength() external view returns (uint256);

  function extraRewards(uint256) external view returns (address);
}

// File: contracts/protocol/libraries/helpers/Errors.sol



// SPDX-License-Identifier: agpl-3.0
pragma solidity ^0.8.0;

/**
 * @title Errors library
 * @author Sturdy, inspiration from Aave
 * @notice Defines the error messages emitted by the different contracts of the Sturdy protocol
 * @dev Error messages prefix glossary:
 *  - VL = ValidationLogic
 *  - MATH = Math libraries
 *  - CT = Common errors between tokens (AToken, VariableDebtToken and StableDebtToken)
 *  - AT = AToken
 *  - SDT = StableDebtToken
 *  - VDT = VariableDebtToken
 *  - LP = LendingPool
 *  - LPAPR = LendingPoolAddressesProviderRegistry
 *  - LPC = LendingPoolConfiguration
 *  - RL = ReserveLogic
 *  - LPCM = LendingPoolCollateralManager
 *  - P = Pausable
 */
library Errors {
  //common errors
  string internal constant CALLER_NOT_POOL_ADMIN = '33'; // 'The caller must be the pool admin'
  string internal constant BORROW_ALLOWANCE_NOT_ENOUGH = '59'; // User borrows on behalf, but allowance are too small

  //contract specific errors
  string internal constant VL_INVALID_AMOUNT = '1'; // 'Amount must be greater than 0'
  string internal constant VL_NO_ACTIVE_RESERVE = '2'; // 'Action requires an active reserve'
  string internal constant VL_RESERVE_FROZEN = '3'; // 'Action cannot be performed because the reserve is frozen'
  string internal constant VL_CURRENT_AVAILABLE_LIQUIDITY_NOT_ENOUGH = '4'; // 'The current liquidity is not enough'
  string internal constant VL_NOT_ENOUGH_AVAILABLE_USER_BALANCE = '5'; // 'User cannot withdraw more than the available balance'
  string internal constant VL_TRANSFER_NOT_ALLOWED = '6'; // 'Transfer cannot be allowed.'
  string internal constant VL_BORROWING_NOT_ENABLED = '7'; // 'Borrowing is not enabled'
  string internal constant VL_INVALID_INTEREST_RATE_MODE_SELECTED = '8'; // 'Invalid interest rate mode selected'
  string internal constant VL_COLLATERAL_BALANCE_IS_0 = '9'; // 'The collateral balance is 0'
  string internal constant VL_HEALTH_FACTOR_LOWER_THAN_LIQUIDATION_THRESHOLD = '10'; // 'Health factor is lesser than the liquidation threshold'
  string internal constant VL_COLLATERAL_CANNOT_COVER_NEW_BORROW = '11'; // 'There is not enough collateral to cover a new borrow'
  string internal constant VL_STABLE_BORROWING_NOT_ENABLED = '12'; // stable borrowing not enabled
  string internal constant VL_COLLATERAL_SAME_AS_BORROWING_CURRENCY = '13'; // collateral is (mostly) the same currency that is being borrowed
  string internal constant VL_AMOUNT_BIGGER_THAN_MAX_LOAN_SIZE_STABLE = '14'; // 'The requested amount is greater than the max loan size in stable rate mode
  string internal constant VL_NO_DEBT_OF_SELECTED_TYPE = '15'; // 'for repayment of stable debt, the user needs to have stable debt, otherwise, he needs to have variable debt'
  string internal 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 internal constant VL_NO_STABLE_RATE_LOAN_IN_RESERVE = '17'; // 'User does not have a stable rate loan in progress on this reserve'
  string internal constant VL_NO_VARIABLE_RATE_LOAN_IN_RESERVE = '18'; // 'User does not have a variable rate loan in progress on this reserve'
  string internal constant VL_UNDERLYING_BALANCE_NOT_GREATER_THAN_0 = '19'; // 'The underlying balance needs to be greater than 0'
  string internal constant VL_DEPOSIT_ALREADY_IN_USE = '20'; // 'User deposit is already being used as collateral'
  string internal constant LP_NOT_ENOUGH_STABLE_BORROW_BALANCE = '21'; // 'User does not have any stable rate loan for this reserve'
  string internal constant LP_INTEREST_RATE_REBALANCE_CONDITIONS_NOT_MET = '22'; // 'Interest rate rebalance conditions were not met'
  string internal constant LP_LIQUIDATION_CALL_FAILED = '23'; // 'Liquidation call failed'
  string internal constant LP_NOT_ENOUGH_LIQUIDITY_TO_BORROW = '24'; // 'There is not enough liquidity available to borrow'
  string internal constant LP_REQUESTED_AMOUNT_TOO_SMALL = '25'; // 'The requested amount is too small for a FlashLoan.'
  string internal constant LP_INCONSISTENT_PROTOCOL_ACTUAL_BALANCE = '26'; // 'The actual balance of the protocol is inconsistent'
  string internal constant LP_CALLER_NOT_LENDING_POOL_CONFIGURATOR = '27'; // 'The caller of the function is not the lending pool configurator'
  string internal constant LP_INCONSISTENT_FLASHLOAN_PARAMS = '28';
  string internal constant CT_CALLER_MUST_BE_LENDING_POOL = '29'; // 'The caller of this function must be a lending pool'
  string internal constant CT_CANNOT_GIVE_ALLOWANCE_TO_HIMSELF = '30'; // 'User cannot give allowance to himself'
  string internal constant CT_TRANSFER_AMOUNT_NOT_GT_0 = '31'; // 'Transferred amount needs to be greater than zero'
  string internal constant RL_RESERVE_ALREADY_INITIALIZED = '32'; // 'Reserve has already been initialized'
  string internal constant LPC_RESERVE_LIQUIDITY_NOT_0 = '34'; // 'The liquidity of the reserve needs to be 0'
  string internal constant LPC_INVALID_ATOKEN_POOL_ADDRESS = '35'; // 'The liquidity of the reserve needs to be 0'
  string internal constant LPC_INVALID_STABLE_DEBT_TOKEN_POOL_ADDRESS = '36'; // 'The liquidity of the reserve needs to be 0'
  string internal constant LPC_INVALID_VARIABLE_DEBT_TOKEN_POOL_ADDRESS = '37'; // 'The liquidity of the reserve needs to be 0'
  string internal constant LPC_INVALID_STABLE_DEBT_TOKEN_UNDERLYING_ADDRESS = '38'; // 'The liquidity of the reserve needs to be 0'
  string internal constant LPC_INVALID_VARIABLE_DEBT_TOKEN_UNDERLYING_ADDRESS = '39'; // 'The liquidity of the reserve needs to be 0'
  string internal constant LPC_INVALID_ADDRESSES_PROVIDER_ID = '40'; // 'The liquidity of the reserve needs to be 0'
  string internal constant LPC_INVALID_CONFIGURATION = '75'; // 'Invalid risk parameters for the reserve'
  string internal constant LPC_CALLER_NOT_EMERGENCY_ADMIN = '76'; // 'The caller must be the emergency admin'
  string internal constant LPAPR_PROVIDER_NOT_REGISTERED = '41'; // 'Provider is not registered'
  string internal constant LPCM_HEALTH_FACTOR_NOT_BELOW_THRESHOLD = '42'; // 'Health factor is not below the threshold'
  string internal constant LPCM_COLLATERAL_CANNOT_BE_LIQUIDATED = '43'; // 'The collateral chosen cannot be liquidated'
  string internal constant LPCM_SPECIFIED_CURRENCY_NOT_BORROWED_BY_USER = '44'; // 'User did not borrow the specified currency'
  string internal constant LPCM_NOT_ENOUGH_LIQUIDITY_TO_LIQUIDATE = '45'; // "There isn't enough liquidity available to liquidate"
  string internal constant LPCM_NO_ERRORS = '46'; // 'No errors'
  string internal constant LP_INVALID_FLASHLOAN_MODE = '47'; //Invalid flashloan mode selected
  string internal constant MATH_MULTIPLICATION_OVERFLOW = '48';
  string internal constant MATH_ADDITION_OVERFLOW = '49';
  string internal constant MATH_DIVISION_BY_ZERO = '50';
  string internal constant RL_LIQUIDITY_INDEX_OVERFLOW = '51'; //  Liquidity index overflows uint128
  string internal constant RL_VARIABLE_BORROW_INDEX_OVERFLOW = '52'; //  Variable borrow index overflows uint128
  string internal constant RL_LIQUIDITY_RATE_OVERFLOW = '53'; //  Liquidity rate overflows uint128
  string internal constant RL_VARIABLE_BORROW_RATE_OVERFLOW = '54'; //  Variable borrow rate overflows uint128
  string internal constant RL_STABLE_BORROW_RATE_OVERFLOW = '55'; //  Stable borrow rate overflows uint128
  string internal constant CT_INVALID_MINT_AMOUNT = '56'; //invalid amount to mint
  string internal constant LP_FAILED_REPAY_WITH_COLLATERAL = '57';
  string internal constant CT_INVALID_BURN_AMOUNT = '58'; //invalid amount to burn
  string internal constant LP_FAILED_COLLATERAL_SWAP = '60';
  string internal constant LP_INVALID_EQUAL_ASSETS_TO_SWAP = '61';
  string internal constant LP_REENTRANCY_NOT_ALLOWED = '62';
  string internal constant LP_CALLER_MUST_BE_AN_ATOKEN = '63';
  string internal constant LP_IS_PAUSED = '64'; // 'Pool is paused'
  string internal constant LP_NO_MORE_RESERVES_ALLOWED = '65';
  string internal constant LP_INVALID_FLASH_LOAN_EXECUTOR_RETURN = '66';
  string internal constant RC_INVALID_LTV = '67';
  string internal constant RC_INVALID_LIQ_THRESHOLD = '68';
  string internal constant RC_INVALID_LIQ_BONUS = '69';
  string internal constant RC_INVALID_DECIMALS = '70';
  string internal constant RC_INVALID_RESERVE_FACTOR = '71';
  string internal constant LPAPR_INVALID_ADDRESSES_PROVIDER_ID = '72';
  string internal constant VL_INCONSISTENT_FLASHLOAN_PARAMS = '73';
  string internal constant LP_INCONSISTENT_PARAMS_LENGTH = '74';
  string internal constant UL_INVALID_INDEX = '77';
  string internal constant LP_NOT_CONTRACT = '78';
  string internal constant SDT_STABLE_DEBT_OVERFLOW = '79';
  string internal constant SDT_BURN_EXCEEDS_BALANCE = '80';
  string internal constant VT_COLLATERAL_DEPOSIT_REQUIRE_ETH = '81'; //Only accept ETH for collateral deposit
  string internal constant VT_COLLATERAL_DEPOSIT_INVALID = '82'; //Collateral deposit failed
  string internal constant VT_LIQUIDITY_DEPOSIT_INVALID = '83'; //Only accept USDC, USDT, DAI for liquidity deposit
  string internal constant VT_COLLATERAL_WITHDRAW_INVALID = '84'; //Collateral withdraw failed
  string internal constant VT_COLLATERAL_WITHDRAW_INVALID_AMOUNT = '85'; //Collateral withdraw has not enough amount
  string internal constant VT_CONVERT_ASSET_BY_CURVE_INVALID = '86'; //Convert asset by curve invalid
  string internal constant VT_PROCESS_YIELD_INVALID = '87'; //Processing yield is invalid
  string internal constant VT_TREASURY_INVALID = '88'; //Treasury is invalid
  string internal constant LP_ATOKEN_INIT_INVALID = '89'; //aToken invalid init
  string internal constant VT_FEE_TOO_BIG = '90'; //Fee is too big
  string internal constant VT_COLLATERAL_DEPOSIT_VAULT_UNAVAILABLE = '91';
  string internal constant LP_LIQUIDATION_CONVERT_FAILED = '92';
  string internal constant VT_DEPLOY_FAILED = '93'; // Vault deploy failed
  string internal constant VT_INVALID_CONFIGURATION = '94'; // Invalid vault configuration
  string internal constant VL_OVERFLOW_MAX_RESERVE_CAPACITY = '95'; // overflow max capacity of reserve
  string internal constant VT_WITHDRAW_AMOUNT_MISMATCH = '96'; // not performed withdraw 100%
  string internal constant VT_SWAP_MISMATCH_RETURNED_AMOUNT = '97'; //Returned amount is not enough
  string internal constant CALLER_NOT_YIELD_PROCESSOR = '98'; // 'The caller must be the pool admin'
  string internal constant VT_EXTRA_REWARDS_INDEX_INVALID = '99'; // Invalid extraRewards index
  string internal constant VT_SWAP_PATH_LENGTH_INVALID = '100'; // Invalid token or fee length
  string internal constant VT_SWAP_PATH_TOKEN_INVALID = '101'; // Invalid token information
  string internal constant CLAIMER_UNAUTHORIZED = '102'; // 'The claimer is not authorized'
  string internal constant YD_INVALID_CONFIGURATION = '103'; // 'The yield distribution's invalid configuration'
  string internal constant CALLER_NOT_EMISSION_MANAGER = '104'; // 'The caller must be emission manager'
  string internal constant CALLER_NOT_INCENTIVE_CONTROLLER = '105'; // 'The caller must be incentive controller'
  string internal constant YD_VR_ASSET_ALREADY_IN_USE = '106'; // Vault is already registered
  string internal constant YD_VR_INVALID_VAULT = '107'; // Invalid vault is used for an asset
  string internal constant YD_VR_INVALID_REWARDS_AMOUNT = '108'; // Rewards amount should be bigger than before
  string internal constant YD_VR_REWARD_TOKEN_NOT_VALID = '109'; // The reward token must be same with configured address
  string internal constant YD_VR_ASSET_NOT_REGISTERED = '110';
  string internal constant YD_VR_CALLER_NOT_VAULT = '111'; // The caller must be same with configured vault address

  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
  }
}

// File: contracts/protocol/tokenization/SturdyInternalAsset.sol



// SPDX-License-Identifier: agpl-3.0
pragma solidity ^0.8.0;
pragma experimental ABIEncoderV2;

import {ERC20} from '../../dependencies/openzeppelin/contracts/ERC20.sol';
import {Ownable} from '../../dependencies/openzeppelin/contracts/Ownable.sol';

/**
 * @notice implementation of the internal asset token contract
 * @author Sturdy
 */
contract SturdyInternalAsset is ERC20, Ownable {
  constructor(
    string memory name,
    string memory symbol,
    uint8 decimals
  ) ERC20(name, symbol) {
    _setupDecimals(decimals);
  }

  /**
   * @dev Function to mint token
   * @param user The user which token is mint
   * @param amount The amount of tokens to mint.
   * @return A boolean that indicates if the operation was successful.
   */
  function mint(address user, uint256 amount) external payable onlyOwner returns (bool) {
    _mint(user, amount);
    return true;
  }

  /**
   * @dev Function to burn token
   * @param user The user which token is burned
   * @param amount The amount of tokens to burn
   */
  function burn(address user, uint256 amount) external payable onlyOwner {
    _burn(user, amount);
  }
}

// File: contracts/protocol/libraries/math/PercentageMath.sol



// SPDX-License-Identifier: agpl-3.0
pragma solidity ^0.8.0;

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

/**
 * @title PercentageMath library
 * @author Sturdy, inspiration from Aave
 * @notice Provides functions to perform percentage calculations
 * @dev Percentages are defined by default with 2 decimals of precision (100.00). The precision is indicated by PERCENTAGE_FACTOR
 * @dev Operations are rounded half up
 **/

library PercentageMath {
  uint256 constant PERCENTAGE_FACTOR = 1e4; //percentage plus two decimals
  uint256 constant HALF_PERCENT = PERCENTAGE_FACTOR / 2;

  /**
   * @dev Executes a percentage multiplication
   * @param value The value of which the percentage needs to be calculated
   * @param percentage The percentage of the value to be calculated
   * @return The percentage of value
   **/
  function percentMul(uint256 value, uint256 percentage) internal pure returns (uint256) {
    if (value == 0 || percentage == 0) {
      return 0;
    }

    return (value * percentage + HALF_PERCENT) / PERCENTAGE_FACTOR;
  }

  /**
   * @dev Executes a percentage division
   * @param value The value of which the percentage needs to be calculated
   * @param percentage The percentage of the value to be calculated
   * @return The value divided the percentage
   **/
  function percentDiv(uint256 value, uint256 percentage) internal pure returns (uint256) {
    uint256 halfPercentage = percentage / 2;

    return (value * PERCENTAGE_FACTOR + halfPercentage) / percentage;
  }
}

// File: contracts/protocol/libraries/types/DataTypes.sol



// SPDX-License-Identifier: agpl-3.0
pragma solidity ^0.8.0;

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;
    //the current stable borrow rate. Expressed in ray
    uint128 currentStableBorrowRate;
    uint40 lastUpdateTimestamp;
    //tokens addresses
    address aTokenAddress;
    address stableDebtTokenAddress;
    address variableDebtTokenAddress;
    //address of the interest rate strategy
    address interestRateStrategyAddress;
    //address of the yield contract
    address yieldAddress;
    //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 59: stable rate borrowing enabled
    //bit 60-63: reserved
    //bit 64-79: reserve factor
    uint256 data;
  }

  struct UserConfigurationMap {
    uint256 data;
  }

  enum InterestRateMode {
    NONE,
    STABLE,
    VARIABLE
  }
}

// File: contracts/interfaces/ILendingPool.sol



// SPDX-License-Identifier: agpl-3.0
pragma solidity ^0.8.0;
pragma experimental ABIEncoderV2;

import {ILendingPoolAddressesProvider} from './ILendingPoolAddressesProvider.sol';
import {DataTypes} from '../protocol/libraries/types/DataTypes.sol';

interface ILendingPool {
  /**
   * @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 aTokens
   * @param amount The amount deposited
   * @param referral The referral code used
   **/
  event Deposit(
    address indexed reserve,
    address user,
    address indexed onBehalfOf,
    uint256 amount,
    uint16 indexed referral
  );

  /**
   * @dev Emitted on withdraw()
   * @param reserve The address of the underlyng asset being withdrawn
   * @param user The address initiating the withdrawal, owner of aTokens
   * @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() and flashLoan() 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() or just
   * initiator of the transaction on flashLoan()
   * @param onBehalfOf The address that will be getting the debt
   * @param amount The amount borrowed out
   * @param borrowRateMode The rate mode: 1 for Stable, 2 for Variable
   * @param borrowRate The numeric rate at which the user has borrowed
   * @param referral The referral code used
   **/
  event Borrow(
    address indexed reserve,
    address user,
    address indexed onBehalfOf,
    uint256 amount,
    uint256 borrowRateMode,
    uint256 borrowRate,
    uint16 indexed referral
  );

  /**
   * @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 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 on flashLoan()
   * @param target The address of the flash loan receiver contract
   * @param initiator The address initiating the flash loan
   * @param asset The address of the asset being flash borrowed
   * @param amount The amount flash borrowed
   * @param premium The fee flash borrowed
   * @param referralCode The referral code used
   **/
  event FlashLoan(
    address indexed target,
    address indexed initiator,
    address indexed asset,
    uint256 amount,
    uint256 premium,
    uint16 referralCode
  );

  /**
   * @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 LendingPool via
   * LendingPoolCollateral manager using a DELEGATECALL
   * This allows to have the events in the generated ABI for LendingPool.
   * @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
   * @param receiveAToken `true` if the liquidators wants to receive the collateral aTokens, `false` if he wants
   * to receive the underlying collateral asset directly
   **/
  event LiquidationCall(
    address indexed collateralAsset,
    address indexed debtAsset,
    address indexed user,
    uint256 debtToCover,
    uint256 liquidatedCollateralAmount,
    address liquidator,
    bool receiveAToken
  );

  /**
   * @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 LendingPool contract. The event is therefore replicated here so it
   * gets added to the LendingPool ABI
   * @param reserve The address of the underlying asset of the reserve
   * @param liquidityRate The new liquidity rate
   * @param stableBorrowRate The new stable borrow 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 stableBorrowRate,
    uint256 variableBorrowRate,
    uint256 liquidityIndex,
    uint256 variableBorrowIndex
  );

  /**
   * @dev Deposits an `amount` of underlying asset into the reserve, receiving in return overlying aTokens.
   * - E.g. User deposits 100 USDC and gets in return 100 aUSDC
   * @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 aTokens, same as msg.sender if the user
   *   wants to receive them on his own wallet, or a different address if the beneficiary of aTokens
   *   is a different wallet
   * @param referralCode Code used to register the integrator originating the operation, for potential rewards.
   *   0 if the action is executed directly by the user, without any middle-man
   **/
  function deposit(
    address asset,
    uint256 amount,
    address onBehalfOf,
    uint16 referralCode
  ) external;

  function depositYield(address asset, uint256 amount) external;

  function getYield(address asset, uint256 amount) external;

  function getTotalBalanceOfAssetPair(address asset) external view returns (uint256, uint256);

  function getBorrowingAssetAndVolumes()
    external
    view
    returns (
      uint256,
      uint256[] memory,
      address[] memory,
      uint256
    );

  function registerVault(address _vaultAddress) external payable;

  /**
   * @dev Withdraws an `amount` of underlying asset from the reserve, burning the equivalent aTokens owned
   * E.g. User has 100 aUSDC, calls withdraw() and receives 100 USDC, burning the 100 aUSDC
   * @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 aToken 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);

  function withdrawFrom(
    address asset,
    uint256 amount,
    address from,
    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 (StableDebtToken or VariableDebtToken)
   * - E.g. User borrows 100 USDC passing as `onBehalfOf` his own address, receiving the 100 USDC in his wallet
   *   and 100 stable/variable debt tokens, depending on the `interestRateMode`
   * @param asset The address of the underlying asset to borrow
   * @param amount The amount to be borrowed
   * @param interestRateMode The interest rate mode at which the user wants to borrow: 1 for Stable, 2 for Variable
   * @param referralCode Code used to register the integrator originating the operation, for potential rewards.
   *   0 if the action is executed directly by the user, without any middle-man
   * @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,
    uint256 interestRateMode,
    uint16 referralCode,
    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/stable 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 rateMode The interest rate mode at of the debt the user wants to repay: 1 for Stable, 2 for Variable
   * @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,
    uint256 rateMode,
    address onBehalfOf
  ) external returns (uint256);

  /**
   * @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
   * @param receiveAToken `true` if the liquidators wants to receive the collateral aTokens, `false` if he wants
   * to receive the underlying collateral asset directly
   **/
  function liquidationCall(
    address collateralAsset,
    address debtAsset,
    address user,
    uint256 debtToCover,
    bool receiveAToken
  ) 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 yieldAddress,
    address aTokenAddress,
    address stableDebtAddress,
    address variableDebtAddress,
    address interestRateStrategyAddress
  ) external payable;

  function setReserveInterestRateStrategyAddress(address reserve, address rateStrategyAddress)
    external
    payable;

  function setConfiguration(address reserve, uint256 configuration) external payable;

  /**
   * @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 (ILendingPoolAddressesProvider);

  function setPause(bool val) external payable;

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

// File: contracts/protocol/vault/GeneralVault.sol



// SPDX-License-Identifier: agpl-3.0
pragma solidity ^0.8.0;
pragma experimental ABIEncoderV2;

import {ILendingPool} from '../../interfaces/ILendingPool.sol';
import {PercentageMath} from '../libraries/math/PercentageMath.sol';
import {Errors} from '../libraries/helpers/Errors.sol';
import {VersionedInitializable} from '../../protocol/libraries/sturdy-upgradeability/VersionedInitializable.sol';
import {ILendingPoolAddressesProvider} from '../../interfaces/ILendingPoolAddressesProvider.sol';
import {IERC20} from '../../dependencies/openzeppelin/contracts/IERC20.sol';
import {IERC20Detailed} from '../../dependencies/openzeppelin/contracts/IERC20Detailed.sol';

/**
 * @title GeneralVault
 * @notice Basic feature of vault
 * @author Sturdy
 **/

abstract contract GeneralVault is VersionedInitializable {
  using PercentageMath for uint256;

  event ProcessYield(address indexed collateralAsset, uint256 yieldAmount);
  event DepositCollateral(address indexed collateralAsset, address indexed from, uint256 amount);
  event WithdrawCollateral(address indexed collateralAsset, address indexed to, uint256 amount);
  event SetTreasuryInfo(address indexed treasuryAddress, uint256 fee);

  modifier onlyAdmin() {
    require(_addressesProvider.getPoolAdmin() == msg.sender, Errors.CALLER_NOT_POOL_ADMIN);
    _;
  }

  modifier onlyYieldProcessor() {
    require(
      _addressesProvider.getAddress('YIELD_PROCESSOR') == msg.sender,
      Errors.CALLER_NOT_YIELD_PROCESSOR
    );
    _;
  }

  struct AssetYield {
    address asset;
    uint256 amount;
  }

  ILendingPoolAddressesProvider internal _addressesProvider;

  // vault fee 20%
  uint256 internal _vaultFee;
  address internal _treasuryAddress;

  uint256 private constant VAULT_REVISION = 0x2;
  address constant ETH = 0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE;

  /**
   * @dev Function is invoked by the proxy contract when the Vault contract is deployed.
   * @param _provider The address of the provider
   **/
  function initialize(ILendingPoolAddressesProvider _provider) external initializer {
    _addressesProvider = _provider;
  }

  function getRevision() internal pure override returns (uint256) {
    return VAULT_REVISION;
  }

  /**
   * @dev Deposits an `amount` of asset as collateral to borrow other asset.
   * @param _asset The asset address for collateral
   *  _asset = 0x0000000000000000000000000000000000000000 means to use ETH as collateral
   * @param _amount The deposit amount
   */
  function depositCollateral(address _asset, uint256 _amount) external payable virtual {
    if (_asset != address(0)) {
      // asset = ERC20
      require(msg.value == 0, Errors.VT_COLLATERAL_DEPOSIT_INVALID);
    } else {
      // asset = ETH
      require(msg.value == _amount, Errors.VT_COLLATERAL_DEPOSIT_REQUIRE_ETH);
    }
    // Deposit asset to vault and receive stAsset
    // Ex: if user deposit 100ETH, this will deposit 100ETH to Lido and receive 100stETH
    (address _stAsset, uint256 _stAssetAmount) = _depositToYieldPool(_asset, _amount);

    // Deposit stAsset to lendingPool, then user will get aToken of stAsset
    ILendingPool(_addressesProvider.getLendingPool()).deposit(
      _stAsset,
      _stAssetAmount,
      msg.sender,
      0
    );

    emit DepositCollateral(_asset, msg.sender, _amount);
  }

  /**
   * @dev Withdraw an `amount` of asset used as collateral to user.
   * @param _asset The asset address for collateral
   *  _asset = 0x0000000000000000000000000000000000000000 means to use ETH as collateral
   * @param _amount The amount to be withdrawn
   * @param _slippage The slippage of the withdrawal amount. 1% = 100
   * @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
   */
  function withdrawCollateral(
    address _asset,
    uint256 _amount,
    uint256 _slippage,
    address _to
  ) external virtual {
    // Before withdraw from lending pool, get the stAsset address and withdrawal amount
    // Ex: In Lido vault, it will return stETH address and same amount
    (address _stAsset, uint256 _stAssetAmount) = _getWithdrawalAmount(_asset, _amount);

    // withdraw from lendingPool, it will convert user's aToken to stAsset
    uint256 _amountToWithdraw = ILendingPool(_addressesProvider.getLendingPool()).withdrawFrom(
      _stAsset,
      _stAssetAmount,
      msg.sender,
      address(this)
    );

    // Withdraw from vault, it will convert stAsset to asset and send to user
    // Ex: In Lido vault, it will return ETH or stETH to user
    uint256 withdrawAmount = _withdrawFromYieldPool(_asset, _amountToWithdraw, _to);

    if (_amount == type(uint256).max) {
      uint256 decimal;
      if (_asset == address(0)) {
        decimal = 18;
      } else {
        decimal = IERC20Detailed(_asset).decimals();
      }

      _amount = (_amountToWithdraw * this.pricePerShare()) / 10**decimal;
    }
    require(
      withdrawAmount >= _amount.percentMul(PercentageMath.PERCENTAGE_FACTOR - _slippage),
      Errors.VT_WITHDRAW_AMOUNT_MISMATCH
    );

    emit WithdrawCollateral(_asset, _to, _amount);
  }

  /**
   * @dev Withdraw an `amount` of asset used as collateral to user on liquidation.
   *  _asset = 0x0000000000000000000000000000000000000000 means to use ETH as collateral
   * @param _amount The amount to be withdrawn
   */
  function withdrawOnLiquidation(address, uint256 _amount) external virtual returns (uint256) {
    return _amount;
  }

  /**
   * @dev Get yield based on strategy and re-deposit
   */
  function processYield() external virtual;

  /**
   * @dev Get price per share based on yield strategy
   */
  function pricePerShare() external view virtual returns (uint256);

  /**
   * @dev Set treasury address and vault fee
   * @param _treasury The treasury address
   * @param _fee The vault fee which has more two decimals, ex: 100% = 100_00
   */
  function setTreasuryInfo(address _treasury, uint256 _fee) external payable onlyAdmin {
    require(_treasury != address(0), Errors.VT_TREASURY_INVALID);
    require(_fee <= 30_00, Errors.VT_FEE_TOO_BIG);
    _treasuryAddress = _treasury;
    _vaultFee = _fee;

    emit SetTreasuryInfo(_treasury, _fee);
  }

  /**
   * @dev Get yield based on strategy and re-deposit
   */
  function _getYield(address _stAsset) internal returns (uint256) {
    uint256 yieldStAsset = _getYieldAmount(_stAsset);
    require(yieldStAsset != 0, Errors.VT_PROCESS_YIELD_INVALID);

    ILendingPool(_addressesProvider.getLendingPool()).getYield(_stAsset, yieldStAsset);
    return yieldStAsset;
  }

  /**
   * @dev Get yield amount based on strategy
   */
  function _getYieldAmount(address _stAsset) internal view returns (uint256) {
    (uint256 stAssetBalance, uint256 aTokenBalance) = ILendingPool(
      _addressesProvider.getLendingPool()
    ).getTotalBalanceOfAssetPair(_stAsset);

    // when deposit for collateral, stAssetBalance = aTokenBalance
    // But stAssetBalance should increase overtime, so vault can grab yield from lendingPool.
    // yield = stAssetBalance - aTokenBalance
    if (stAssetBalance > aTokenBalance) return stAssetBalance - aTokenBalance;

    return 0;
  }

  /**
   * @dev Deposit to yield pool based on strategy and receive stAsset
   */
  function _depositToYieldPool(address _asset, uint256 _amount)
    internal
    virtual
    returns (address, uint256);

  /**
   * @dev Withdraw from yield pool based on strategy with stAsset and deliver asset
   */
  function _withdrawFromYieldPool(
    address _asset,
    uint256 _amount,
    address _to
  ) internal virtual returns (uint256);

  /**
   * @dev Get Withdrawal amount of stAsset based on strategy
   */
  function _getWithdrawalAmount(address _asset, uint256 _amount)
    internal
    view
    virtual
    returns (address, uint256);
}

// File: contracts/incentives/VariableYieldDistribution.sol



// SPDX-License-Identifier: agpl-3.0
pragma solidity ^0.8.0;
pragma experimental ABIEncoderV2;

import {SafeERC20} from '../dependencies/openzeppelin/contracts/SafeERC20.sol';
import {DistributionTypes} from '../lib/DistributionTypes.sol';
import {VersionedInitializable} from '../protocol/libraries/sturdy-upgradeability/VersionedInitializable.sol';
import {DistributionManager} from './DistributionManager.sol';
import {IERC20} from '../dependencies/openzeppelin/contracts/IERC20.sol';
import {IScaledBalanceToken} from '../interfaces/IScaledBalanceToken.sol';
import {ILendingPoolAddressesProvider} from '../interfaces/ILendingPoolAddressesProvider.sol';
import {UserData, AssetData, AggregatedRewardsData} from '../interfaces/IVariableYieldDistribution.sol';
import {IncentiveVault} from '../protocol/vault/IncentiveVault.sol';
import {Errors} from '../protocol/libraries/helpers/Errors.sol';

/**
 * @title VariableYieldDistribution
 * @notice Distributor contract that sends some rewards to borrowers who provide some special tokens such as Curve LP tokens.
 * @author Sturdy
 **/
contract VariableYieldDistribution is VersionedInitializable {
  using SafeERC20 for IERC20;

  uint256 private constant REVISION = 1;
  uint8 private constant PRECISION = 27;
  address public immutable EMISSION_MANAGER;

  ILendingPoolAddressesProvider internal _addressProvider;

  mapping(address => AssetData) public assets;

  event AssetRegistered(address indexed asset, address indexed yieldAddress);
  event AssetIndexUpdated(address indexed asset, uint256 index, uint256 rewardsAmount);
  event UserIndexUpdated(
    address indexed user,
    address indexed asset,
    uint256 index,
    uint256 unclaimedRewardsAmount
  );
  event RewardsReceived(address indexed asset, address indexed rewardToken, uint256 receivedAmount);
  event RewardsAccrued(address indexed user, address indexed asset, uint256 amount);
  event RewardsClaimed(
    address indexed asset,
    address indexed user,
    address indexed to,
    uint256 amount
  );

  modifier onlyEmissionManager() {
    require(msg.sender == EMISSION_MANAGER, Errors.CALLER_NOT_EMISSION_MANAGER);
    _;
  }

  modifier onlyIncentiveController() {
    require(
      msg.sender == _addressProvider.getIncentiveController(),
      Errors.CALLER_NOT_INCENTIVE_CONTROLLER
    );
    _;
  }

  constructor(address emissionManager) {
    EMISSION_MANAGER = emissionManager;
  }

  /**
   * @dev Initialize IStakedTokenIncentivesController
   * @param _provider the address of the corresponding addresses provider
   **/
  function initialize(ILendingPoolAddressesProvider _provider) external initializer {
    _addressProvider = _provider;
  }

  /**
   * @dev Register an asset with vault which will keep some of yield for borrowers
   * @param asset The address of the reference asset
   * @param yieldAddress The address of the vault
   */
  function registerAsset(address asset, address yieldAddress) external payable onlyEmissionManager {
    AssetData storage assetData = assets[asset];
    address rewardToken = IncentiveVault(yieldAddress).getIncentiveToken();

    require(assetData.yieldAddress == address(0), Errors.YD_VR_ASSET_ALREADY_IN_USE);
    require(rewardToken != address(0), Errors.YD_VR_INVALID_VAULT);

    uint256 totalStaked = IScaledBalanceToken(asset).scaledTotalSupply();
    assetData.yieldAddress = yieldAddress;
    assetData.rewardToken = rewardToken;

    (uint256 lastAvailableRewards, uint256 increasedRewards) = _getAvailableRewardsAmount(
      assetData
    );

    _updateAssetStateInternal(
      asset,
      assetData,
      totalStaked,
      lastAvailableRewards,
      increasedRewards
    );

    emit AssetRegistered(asset, yieldAddress);
  }

  function receivedRewards(
    address asset,
    address rewardToken,
    uint256 amount
  ) external {
    AssetData storage assetData = assets[asset];
    address _rewardToken = assetData.rewardToken;
    address _yieldAddress = assetData.yieldAddress;
    uint256 lastAvailableRewards = assetData.lastAvailableRewards;

    require(msg.sender == _yieldAddress, Errors.YD_VR_CALLER_NOT_VAULT);
    require(_rewardToken != address(0), Errors.YD_VR_ASSET_NOT_REGISTERED);
    require(rewardToken == _rewardToken, Errors.YD_VR_REWARD_TOKEN_NOT_VALID);
    require(amount >= lastAvailableRewards, Errors.YD_VR_INVALID_REWARDS_AMOUNT);

    uint256 increasedRewards = amount - lastAvailableRewards;
    uint256 totalStaked = IScaledBalanceToken(asset).scaledTotalSupply();

    _updateAssetStateInternal(asset, assetData, totalStaked, 0, increasedRewards);

    emit RewardsReceived(asset, rewardToken, amount);
  }

  function handleAction(
    address user,
    address asset,
    uint256 totalSupply,
    uint256 userBalance
  ) external payable onlyIncentiveController {
    uint256 accruedRewards = _updateUserAssetInternal(user, asset, userBalance, totalSupply);
    if (accruedRewards != 0) {
      emit RewardsAccrued(user, asset, accruedRewards);
    }
  }

  function getRewardsBalance(address[] calldata assets, address user)
    external
    view
    returns (AggregatedRewardsData[] memory)
  {
    uint256 length = assets.length;
    AggregatedRewardsData[] memory rewards = new AggregatedRewardsData[](length);

    for (uint256 i; i < length; ++i) {
      (uint256 stakedByUser, uint256 totalStaked) = IScaledBalanceToken(assets[i])
        .getScaledUserBalanceAndSupply(user);
      rewards[i].asset = assets[i];
      (rewards[i].rewardToken, rewards[i].balance) = _getUnclaimedRewards(
        user,
        assets[i],
        stakedByUser,
        totalStaked
      );
    }

    return rewards;
  }

  function claimRewards(
    address asset,
    uint256 amount,
    address to
  ) external returns (uint256) {
    require(to != address(0), 'INVALID_TO_ADDRESS');
    return _claimRewards(asset, amount, msg.sender, to);
  }

  function getUserAssetData(address user, address asset) public view returns (uint256, uint256) {
    UserData storage userData = assets[asset].users[user];
    return (userData.index, userData.unclaimedRewards);
  }

  function getAssetData(address asset)
    public
    view
    returns (
      uint256,
      address,
      address,
      uint256
    )
  {
    return (
      assets[asset].index,
      assets[asset].yieldAddress,
      assets[asset].rewardToken,
      assets[asset].lastAvailableRewards
    );
  }

  /**
   * @dev returns the revision of the implementation contract
   */
  function getRevision() internal pure override returns (uint256) {
    return REVISION;
  }

  /**
   * @dev Claims reward for an user on behalf, on all the assets of the lending pool, accumulating the pending rewards.
   * @param amount Amount of rewards to claim
   * @param user Address to check and claim rewards
   * @param to Address that will be receiving the rewards
   * @return Rewards claimed
   **/
  function _claimRewards(
    address asset,
    uint256 amount,
    address user,
    address to
  ) internal returns (uint256) {
    if (amount == 0) {
      return 0;
    }

    AssetData storage assetData = assets[asset];
    UserData storage userData = assetData.users[user];
    address rewardToken = assetData.rewardToken;

    (uint256 stakedByUser, uint256 totalStaked) = IScaledBalanceToken(asset)
      .getScaledUserBalanceAndSupply(user);

    _updateUserAssetInternal(user, asset, stakedByUser, totalStaked);

    uint256 unclaimedRewards = userData.unclaimedRewards;
    if (unclaimedRewards == 0) {
      return 0;
    }

    uint256 amountToClaim = amount > unclaimedRewards ? unclaimedRewards : amount;

    IERC20 stakeToken = IERC20(rewardToken);
    if (stakeToken.balanceOf(address(this)) >= amountToClaim) {
      stakeToken.safeTransfer(to, amountToClaim);
      userData.unclaimedRewards = unclaimedRewards - amountToClaim;
      emit RewardsClaimed(asset, user, to, amountToClaim);
    }

    return amountToClaim;
  }

  /**
   * @dev Updates the state of one distribution, mainly rewards index and timestamp
   * @param asset The address of the asset being updated
   * @param assetData Storage pointer to the distribution's config
   * @param totalStaked Current total of staked assets for this distribution
   * @return The new distribution index
   **/
  function _updateAssetStateInternal(
    address asset,
    AssetData storage assetData,
    uint256 totalStaked,
    uint256 lastAvailableRewards,
    uint256 increasedRewards
  ) internal returns (uint256) {
    uint256 oldIndex = assetData.index;
    uint256 oldAvailableRewards = assetData.lastAvailableRewards;

    uint256 newIndex = _getAssetIndex(oldIndex, increasedRewards, totalStaked);

    if (newIndex != oldIndex || lastAvailableRewards != oldAvailableRewards) {
      assetData.index = newIndex;
      assetData.lastAvailableRewards = lastAvailableRewards;
      emit AssetIndexUpdated(asset, newIndex, lastAvailableRewards);
    }

    return newIndex;
  }

  /**
   * @dev Updates the state of an user in a distribution
   * @param user The user's address
   * @param asset The address of the reference asset of the distribution
   * @param stakedByUser Amount of tokens staked by the user in the distribution at the moment
   * @param totalStaked Total tokens staked in the distribution
   * @return The accrued rewards for the user until the moment
   **/
  function _updateUserAssetInternal(
    address user,
    address asset,
    uint256 stakedByUser,
    uint256 totalStaked
  ) internal returns (uint256) {
    AssetData storage assetData = assets[asset];
    UserData storage userData = assetData.users[user];
    uint256 userIndex = userData.index;
    uint256 unclaimedRewards = userData.unclaimedRewards;
    uint256 accruedRewards;

    (uint256 lastAvailableRewards, uint256 increasedRewards) = _getAvailableRewardsAmount(
      assetData
    );
    uint256 newIndex = _updateAssetStateInternal(
      asset,
      assetData,
      totalStaked,
      lastAvailableRewards,
      increasedRewards
    );

    if (userIndex == newIndex) return accruedRewards;

    if (stakedByUser != 0) {
      accruedRewards = _getRewards(stakedByUser, newIndex, userIndex);
      unclaimedRewards += accruedRewards;
    }

    userData.index = newIndex;
    userData.unclaimedRewards = unclaimedRewards;
    emit UserIndexUpdated(user, asset, newIndex, unclaimedRewards);

    return accruedRewards;
  }

  /**
   * @dev Return the accrued rewards for an user over a list of distribution
   * @param user The address of the user
   * @param asset The address of the asset
   * @param stakedByUser The balance of the user of the asset
   * @param totalStaked The total staked amount of the asset
   * @return rewardToken The address of the reward token
   * @return unclaimedRewards The accrued rewards for the user until the moment
   **/
  function _getUnclaimedRewards(
    address user,
    address asset,
    uint256 stakedByUser,
    uint256 totalStaked
  ) internal view returns (address rewardToken, uint256 unclaimedRewards) {
    AssetData storage assetData = assets[asset];
    rewardToken = assetData.rewardToken;
    uint256 oldIndex = assetData.index;
    (, uint256 increasedRewards) = _getAvailableRewardsAmount(assetData);

    UserData storage userData = assetData.users[user];
    uint256 userIndex = userData.index;
    unclaimedRewards = userData.unclaimedRewards;

    uint256 assetIndex = _getAssetIndex(oldIndex, increasedRewards, totalStaked);

    if (stakedByUser != 0) {
      unclaimedRewards += _getRewards(stakedByUser, assetIndex, userIndex);
    }
  }

  /**
   * @dev Internal function for the calculation of user's rewards on a distribution
   * @param principalUserBalance Amount staked by the user on a distribution
   * @param reserveIndex Current index of the distribution
   * @param userIndex Index stored for the user, representation his staking moment
   * @return The rewards
   **/
  function _getRewards(
    uint256 principalUserBalance,
    uint256 reserveIndex,
    uint256 userIndex
  ) internal pure returns (uint256) {
    return (principalUserBalance * (reserveIndex - userIndex)) / 10**uint256(PRECISION);
  }

  /**
   * @dev Calculates the next value of an specific distribution index, with validations
   * @param currentIndex Current index of the distribution
   * @param increasedRewards Earned Amount
   * @param totalBalance of tokens considered for the distribution
   * @return The new index.
   **/
  function _getAssetIndex(
    uint256 currentIndex,
    uint256 increasedRewards,
    uint256 totalBalance
  ) internal pure returns (uint256) {
    if (increasedRewards == 0 || totalBalance == 0) {
      return currentIndex;
    }

    return (increasedRewards * (10**uint256(PRECISION))) / totalBalance + currentIndex;
  }

  function _getAvailableRewardsAmount(AssetData storage assetData)
    internal
    view
    returns (uint256 lastAvailableRewards, uint256 increasedRewards)
  {
    address vault = assetData.yieldAddress;
    uint256 oldAmount = assetData.lastAvailableRewards;
    lastAvailableRewards = IncentiveVault(vault).getCurrentTotalIncentiveAmount();
    require(lastAvailableRewards >= oldAmount, Errors.YD_VR_INVALID_REWARDS_AMOUNT);
    increasedRewards = lastAvailableRewards - oldAmount;
  }
}

// File: contracts/protocol/libraries/sturdy-upgradeability/VersionedInitializable.sol



// SPDX-License-Identifier: agpl-3.0
pragma solidity ^0.8.0;

/**
 * @title VersionedInitializable
 *
 * @dev Helper contract to implement initializer functions. To use it, replace
 * the constructor with a function that has the `initializer` modifier.
 * WARNING: Unlike constructors, initializer functions must be manually
 * invoked. This applies both to deploying an Initializable contract, as well
 * as extending an Initializable contract via inheritance.
 * WARNING: When used with inheritance, manual care must be taken to not invoke
 * a parent initializer twice, or ensure that all initializers are idempotent,
 * because this is not dealt with automatically as with constructors.
 *
 * @author Sturdy, inspiration from Aave
 */
abstract contract VersionedInitializable {
  /**
   * @dev Indicates that the contract has been initialized.
   */
  uint256 private lastInitializedRevision;

  /**
   * @dev Indicates that the contract is in the process of being initialized.
   */
  bool private initializing;

  /**
   * @dev Modifier to use in the initializer function of a contract.
   */
  modifier initializer() {
    uint256 revision = getRevision();
    require(
      initializing || isConstructor() || revision > lastInitializedRevision,
      'Contract instance has already been initialized'
    );

    bool isTopLevelCall = !initializing;
    if (isTopLevelCall) {
      initializing = true;
      lastInitializedRevision = revision;
    }

    _;

    if (isTopLevelCall) {
      initializing = false;
    }
  }

  /**
   * @dev returns the revision number of the contract
   * Needs to be defined in the inherited class as a constant.
   **/
  function getRevision() internal pure virtual returns (uint256);

  /**
   * @dev Returns true if and only if the function is running in the constructor
   **/
  function isConstructor() private view returns (bool) {
    // extcodesize checks the size of the code stored in an address, and
    // address returns the current address. Since the code is still not
    // deployed when running a constructor, any checks on its code size will
    // yield zero, making it an effective way to detect if a contract is
    // under construction or not.
    uint256 cs;
    //solium-disable-next-line
    assembly {
      cs := extcodesize(address())
    }
    return cs == 0;
  }

  // Reserved storage space to allow for layout changes in the future.
  uint256[50] private ______gap;
}

// File: contracts/interfaces/ILendingPoolAddressesProvider.sol



// SPDX-License-Identifier: agpl-3.0
pragma solidity ^0.8.0;

/**
 * @title LendingPoolAddressesProvider 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 Sturdy Governance
 * @author Sturdy, inspiration from Aave
 **/
interface ILendingPoolAddressesProvider {
  event MarketIdSet(string newMarketId);
  event LendingPoolUpdated(address indexed newAddress);
  event IncentiveControllerUpdated(address indexed newAddress);
  event IncentiveTokenUpdated(address indexed newAddress);
  event ConfigurationAdminUpdated(address indexed newAddress);
  event EmergencyAdminUpdated(address indexed newAddress);
  event LendingPoolConfiguratorUpdated(address indexed newAddress);
  event LendingPoolCollateralManagerUpdated(address indexed newAddress);
  event PriceOracleUpdated(address indexed newAddress);
  event LendingRateOracleUpdated(address indexed newAddress);
  event ProxyCreated(bytes32 id, address indexed newAddress);
  event AddressSet(bytes32 id, address indexed newAddress, bool hasProxy);

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

  function setMarketId(string calldata marketId) external payable;

  function setAddress(bytes32 id, address newAddress) external payable;

  function setAddressAsProxy(bytes32 id, address impl) external payable;

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

  function getLendingPool() external view returns (address);

  function setLendingPoolImpl(address pool) external payable;

  function getIncentiveController() external view returns (address);

  function setIncentiveControllerImpl(address incentiveController) external payable;

  function getIncentiveToken() external view returns (address);

  function setIncentiveTokenImpl(address incentiveToken) external payable;

  function getLendingPoolConfigurator() external view returns (address);

  function setLendingPoolConfiguratorImpl(address configurator) external payable;

  function getLendingPoolCollateralManager() external view returns (address);

  function setLendingPoolCollateralManager(address manager) external payable;

  function getPoolAdmin() external view returns (address);

  function setPoolAdmin(address admin) external payable;

  function getEmergencyAdmin() external view returns (address);

  function setEmergencyAdmin(address admin) external payable;

  function getPriceOracle() external view returns (address);

  function setPriceOracle(address priceOracle) external payable;

  function getLendingRateOracle() external view returns (address);

  function setLendingRateOracle(address lendingRateOracle) external payable;
}

// File: contracts/dependencies/openzeppelin/contracts/Address.sol



// SPDX-License-Identifier: agpl-3.0
pragma solidity ^0.8.0;

/**
 * @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');
  }
}

// File: contracts/lib/DistributionTypes.sol



// SPDX-License-Identifier: agpl-3.0
pragma solidity ^0.8.0;
pragma experimental ABIEncoderV2;

library DistributionTypes {
  struct AssetConfigInput {
    uint104 emissionPerSecond;
    uint256 totalStaked;
    address underlyingAsset;
  }

  struct UserStakeInput {
    address underlyingAsset;
    uint256 stakedByUser;
    uint256 totalStaked;
  }

  struct AssetConfigInputForYield {
    uint256 totalStaked;
    address underlyingAsset;
  }
}

// File: contracts/incentives/DistributionManager.sol



// SPDX-License-Identifier: agpl-3.0
pragma solidity ^0.8.0;
pragma experimental ABIEncoderV2;

import {ISturdyDistributionManager} from '../interfaces/ISturdyDistributionManager.sol';
import {DistributionTypes} from '../lib/DistributionTypes.sol';

/**
 * @title DistributionManager
 * @notice Accounting contract to manage multiple staking distributions
 * @author Sturdy
 **/
contract DistributionManager is ISturdyDistributionManager {
  struct AssetData {
    uint104 emissionPerSecond;
    uint104 index;
    uint40 lastUpdateTimestamp;
    mapping(address => uint256) users;
  }

  address public immutable EMISSION_MANAGER;

  uint8 internal constant _PRECISION = 18;

  mapping(address => AssetData) public assets;

  uint256 internal _distributionEnd;

  modifier onlyEmissionManager() {
    require(msg.sender == EMISSION_MANAGER, 'ONLY_EMISSION_MANAGER');
    _;
  }

  constructor(address emissionManager) {
    EMISSION_MANAGER = emissionManager;
  }

  /// @inheritdoc ISturdyDistributionManager
  function setDistributionEnd(uint256 distributionEnd)
    external
    payable
    override
    onlyEmissionManager
  {
    _distributionEnd = distributionEnd;
    emit DistributionEndUpdated(distributionEnd);
  }

  /// @inheritdoc ISturdyDistributionManager
  function getDistributionEnd() external view override returns (uint256) {
    return _distributionEnd;
  }

  /// @inheritdoc ISturdyDistributionManager
  function DISTRIBUTION_END() external view virtual override returns (uint256) {
    return _distributionEnd;
  }

  /// @inheritdoc ISturdyDistributionManager
  function getUserAssetData(address user, address asset)
    public
    view
    virtual
    override
    returns (uint256)
  {
    return assets[asset].users[user];
  }

  /// @inheritdoc ISturdyDistributionManager
  function getAssetData(address asset)
    public
    view
    virtual
    override
    returns (
      uint256,
      uint256,
      uint256
    )
  {
    return (
      assets[asset].index,
      assets[asset].emissionPerSecond,
      assets[asset].lastUpdateTimestamp
    );
  }

  /**
   * @dev Configure the assets for a specific emission
   * @param assetsConfigInput The array of each asset configuration
   **/
  function _configureAssets(DistributionTypes.AssetConfigInput[] memory assetsConfigInput)
    internal
  {
    uint256 length = assetsConfigInput.length;
    for (uint256 i; i < length; ++i) {
      AssetData storage assetConfig = assets[assetsConfigInput[i].underlyingAsset];

      _updateAssetStateInternal(
        assetsConfigInput[i].underlyingAsset,
        assetConfig,
        assetsConfigInput[i].totalStaked
      );

      assetConfig.emissionPerSecond = assetsConfigInput[i].emissionPerSecond;

      emit AssetConfigUpdated(
        assetsConfigInput[i].underlyingAsset,
        assetsConfigInput[i].emissionPerSecond
      );
    }
  }

  /**
   * @dev Updates the state of one distribution, mainly rewards index and timestamp
   * @param asset The address of the asset being updated
   * @param assetConfig Storage pointer to the distribution's config
   * @param totalStaked Current total of staked assets for this distribution
   * @return The new distribution index
   **/
  function _updateAssetStateInternal(
    address asset,
    AssetData storage assetConfig,
    uint256 totalStaked
  ) internal returns (uint256) {
    uint256 oldIndex = assetConfig.index;
    uint256 emissionPerSecond = assetConfig.emissionPerSecond;
    uint128 lastUpdateTimestamp = assetConfig.lastUpdateTimestamp;

    if (block.timestamp == lastUpdateTimestamp) {
      return oldIndex;
    }

    uint256 newIndex = _getAssetIndex(
      oldIndex,
      emissionPerSecond,
      lastUpdateTimestamp,
      totalStaked
    );

    if (newIndex == oldIndex) {
      assetConfig.lastUpdateTimestamp = uint40(block.timestamp);
    } else {
      require(uint104(newIndex) == newIndex, 'Index overflow');
      //optimization: storing one after another saves one SSTORE
      assetConfig.index = uint104(newIndex);
      assetConfig.lastUpdateTimestamp = uint40(block.timestamp);
      emit AssetIndexUpdated(asset, newIndex);
    }

    return newIndex;
  }

  /**
   * @dev Updates the state of an user in a distribution
   * @param user The user's address
   * @param asset The address of the reference asset of the distribution
   * @param stakedByUser Amount of tokens staked by the user in the distribution at the moment
   * @param totalStaked Total tokens staked in the distribution
   * @return The accrued rewards for the user until the moment
   **/
  function _updateUserAssetInternal(
    address user,
    address asset,
    uint256 stakedByUser,
    uint256 totalStaked
  ) internal returns (uint256) {
    AssetData storage assetData = assets[asset];
    uint256 userIndex = assetData.users[user];
    uint256 accruedRewards;

    uint256 newIndex = _updateAssetStateInternal(asset, assetData, totalStaked);

    if (userIndex == newIndex) return accruedRewards;

    if (stakedByUser != 0) {
      accruedRewards = _getRewards(stakedByUser, newIndex, userIndex);
    }

    assetData.users[user] = newIndex;
    emit UserIndexUpdated(user, asset, newIndex);

    return accruedRewards;
  }

  /**
   * @dev Used by "frontend" stake contracts to update the data of an user when claiming rewards from there
   * @param user The address of the user
   * @param stakes List of structs of the user data related with his stake
   * @return The accrued rewards for the user until the moment
   **/
  function _claimRewards(address user, DistributionTypes.UserStakeInput[] memory stakes)
    internal
    returns (uint256)
  {
    uint256 accruedRewards;
    uint256 length = stakes.length;
    for (uint256 i; i < length; ++i) {
      accruedRewards =
        accruedRewards +
        _updateUserAssetInternal(
          user,
          stakes[i].underlyingAsset,
          stakes[i].stakedByUser,
          stakes[i].totalStaked
        );
    }

    return accruedRewards;
  }

  /**
   * @dev Return the accrued rewards for an user over a list of distribution
   * @param user The address of the user
   * @param stakes List of structs of the user data related with his stake
   * @return The accrued rewards for the user until the moment
   **/
  function _getUnclaimedRewards(address user, DistributionTypes.UserStakeInput[] memory stakes)
    internal
    view
    returns (uint256)
  {
    uint256 accruedRewards;
    uint256 length = stakes.length;
    for (uint256 i; i < length; ++i) {
      AssetData storage assetConfig = assets[stakes[i].underlyingAsset];
      uint256 assetIndex = _getAssetIndex(
        assetConfig.index,
        assetConfig.emissionPerSecond,
        assetConfig.lastUpdateTimestamp,
        stakes[i].totalStaked
      );

      accruedRewards =
        accruedRewards +
        _getRewards(stakes[i].stakedByUser, assetIndex, assetConfig.users[user]);
    }
    return accruedRewards;
  }

  /**
   * @dev Internal function for the calculation of user's rewards on a distribution
   * @param principalUserBalance Amount staked by the user on a distribution
   * @param reserveIndex Current index of the distribution
   * @param userIndex Index stored for the user, representation his staking moment
   * @return The rewards
   **/
  function _getRewards(
    uint256 principalUserBalance,
    uint256 reserveIndex,
    uint256 userIndex
  ) internal pure returns (uint256) {
    return (principalUserBalance * (reserveIndex - userIndex)) / 10**uint256(_PRECISION);
  }

  /**
   * @dev Calculates the next value of an specific distribution index, with validations
   * @param currentIndex Current index of the distribution
   * @param emissionPerSecond Representing the total rewards distributed per second per asset unit, on the distribution
   * @param lastUpdateTimestamp Last moment this distribution was updated
   * @param totalBalance of tokens considered for the distribution
   * @return The new index.
   **/
  function _getAssetIndex(
    uint256 currentIndex,
    uint256 emissionPerSecond,
    uint128 lastUpdateTimestamp,
    uint256 totalBalance
  ) internal view returns (uint256) {
    uint256 distributionEnd = _distributionEnd;
    if (
      emissionPerSecond == 0 ||
      totalBalance == 0 ||
      lastUpdateTimestamp == block.timestamp ||
      lastUpdateTimestamp >= distributionEnd
    ) {
      return currentIndex;
    }

    uint256 currentTimestamp = block.timestamp > distributionEnd
      ? distributionEnd
      : block.timestamp;
    uint256 timeDelta = currentTimestamp - lastUpdateTimestamp;
    return
      ((emissionPerSecond * timeDelta * (10**uint256(_PRECISION))) / totalBalance) + currentIndex;
  }
}

// File: contracts/interfaces/IScaledBalanceToken.sol



// SPDX-License-Identifier: agpl-3.0
pragma solidity ^0.8.0;

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);
}

// File: contracts/interfaces/IVariableYieldDistribution.sol



// SPDX-License-Identifier: agpl-3.0
pragma solidity ^0.8.0;
pragma experimental ABIEncoderV2;

struct UserData {
  uint256 index;
  uint256 unclaimedRewards;
}

struct AssetData {
  uint256 index;
  uint256 lastAvailableRewards;
  address rewardToken; // The address of reward token
  address yieldAddress; // The address of vault
  mapping(address => UserData) users;
}

struct AggregatedRewardsData {
  address asset;
  address rewardToken;
  uint256 balance;
}

interface IVariableYieldDistribution {
  function claimRewards(
    address asset,
    uint256 amount,
    address to
  ) external returns (uint256);

  function getRewardsBalance(address[] calldata assets, address user)
    external
    view
    returns (AggregatedRewardsData[] memory);
}

// File: contracts/interfaces/ISturdyDistributionManager.sol



// SPDX-License-Identifier: agpl-3.0
pragma solidity ^0.8.0;
pragma experimental ABIEncoderV2;

import {DistributionTypes} from '../lib/DistributionTypes.sol';

interface ISturdyDistributionManager {
  event AssetConfigUpdated(address indexed asset, uint256 emission);
  event AssetIndexUpdated(address indexed asset, uint256 index);
  event UserIndexUpdated(address indexed user, address indexed asset, uint256 index);
  event DistributionEndUpdated(uint256 newDistributionEnd);

  /**
   * @dev Sets the end date for the distribution
   * @param distributionEnd The end date timestamp
   **/
  function setDistributionEnd(uint256 distributionEnd) external payable;

  /**
   * @dev Gets the end date for the distribution
   * @return The end of the distribution
   **/
  function getDistributionEnd() external view returns (uint256);

  /**
   * @dev for backwards compatibility with the previous DistributionManager used
   * @return The end of the distribution
   **/
  function DISTRIBUTION_END() external view returns (uint256);

  /**
   * @dev Returns the data of an user on a distribution
   * @param user Address of the user
   * @param asset The address of the reference asset of the distribution
   * @return The new index
   **/
  function getUserAssetData(address user, address asset) external view returns (uint256);

  /**
   * @dev Returns the configuration of the distribution for a certain asset
   * @param asset The address of the reference asset of the distribution
   * @return The asset index, the emission per second and the last updated timestamp
   **/
  function getAssetData(address asset)
    external
    view
    returns (
      uint256,
      uint256,
      uint256
    );
}

// File: contracts/dependencies/openzeppelin/contracts/ERC20.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

import './Context.sol';
import './IERC20.sol';
import './Address.sol';

/**
 * @dev Implementation of the {IERC20} interface.
 *
 * This implementation is agnostic to the way tokens are created. This means
 * that a supply mechanism has to be added in a derived contract using {_mint}.
 * For a generic mechanism see {ERC20PresetMinterPauser}.
 *
 * TIP: For a detailed writeup see our guide
 * https://forum.zeppelin.solutions/t/how-to-implement-erc20-supply-mechanisms/226[How
 * to implement supply mechanisms].
 *
 * We have followed general OpenZeppelin guidelines: functions revert instead
 * of returning `false` on failure. This behavior is nonetheless conventional
 * and does not conflict with the expectations of ERC20 applications.
 *
 * Additionally, an {Approval} event is emitted on calls to {transferFrom}.
 * This allows applications to reconstruct the allowance for all accounts just
 * by listening to said events. Other implementations of the EIP may not emit
 * these events, as it isn't required by the specification.
 *
 * Finally, the non-standard {decreaseAllowance} and {increaseAllowance}
 * functions have been added to mitigate the well-known issues around setting
 * allowances. See {IERC20-approve}.
 */
contract ERC20 is Context, IERC20 {
  using Address for address;

  mapping(address => uint256) private _balances;

  mapping(address => mapping(address => uint256)) private _allowances;

  uint256 private _totalSupply;

  string private _name;
  string private _symbol;
  uint8 private _decimals;

  /**
   * @dev Sets the values for {name} and {symbol}, initializes {decimals} with
   * a default value of 18.
   *
   * To select a different value for {decimals}, use {_setupDecimals}.
   *
   * All three of these values are immutable: they can only be set once during
   * construction.
   */
  constructor(string memory name, string memory symbol) {
    _name = name;
    _symbol = symbol;
    _decimals = 18;
  }

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

  /**
   * @dev Returns the symbol of the token, usually a shorter version of the
   * name.
   */
  function symbol() public view returns (string memory) {
    return _symbol;
  }

  /**
   * @dev Returns the number of decimals used to get its user representation.
   * For example, if `decimals` equals `2`, a balance of `505` tokens should
   * be displayed to a user as `5,05` (`505 / 10 ** 2`).
   *
   * Tokens usually opt for a value of 18, imitating the relationship between
   * Ether and Wei. This is the value {ERC20} uses, unless {_setupDecimals} is
   * called.
   *
   * NOTE: This information is only used for _display_ purposes: it in
   * no way affects any of the arithmetic of the contract, including
   * {IERC20-balanceOf} and {IERC20-transfer}.
   */
  function decimals() public view returns (uint8) {
    return _decimals;
  }

  /**
   * @dev See {IERC20-totalSupply}.
   */
  function totalSupply() public view override returns (uint256) {
    return _totalSupply;
  }

  /**
   * @dev See {IERC20-balanceOf}.
   */
  function balanceOf(address account) public view override returns (uint256) {
    return _balances[account];
  }

  /**
   * @dev See {IERC20-transfer}.
   *
   * Requirements:
   *
   * - `recipient` cannot be the zero address.
   * - the caller must have a balance of at least `amount`.
   */
  function transfer(address recipient, uint256 amount) public virtual override returns (bool) {
    _transfer(_msgSender(), recipient, amount);
    return true;
  }

  /**
   * @dev See {IERC20-allowance}.
   */
  function allowance(address owner, address spender)
    public
    view
    virtual
    override
    returns (uint256)
  {
    return _allowances[owner][spender];
  }

  /**
   * @dev See {IERC20-approve}.
   *
   * Requirements:
   *
   * - `spender` cannot be the zero address.
   */
  function approve(address spender, uint256 amount) public virtual override returns (bool) {
    _approve(_msgSender(), spender, amount);
    return true;
  }

  /**
   * @dev See {IERC20-transferFrom}.
   *
   * Emits an {Approval} event indicating the updated allowance. This is not
   * required by the EIP. See the note at the beginning of {ERC20};
   *
   * Requirements:
   * - `sender` and `recipient` cannot be the zero address.
   * - `sender` must have a balance of at least `amount`.
   * - the caller must have allowance for ``sender``'s tokens of at least
   * `amount`.
   */
  function transferFrom(
    address sender,
    address recipient,
    uint256 amount
  ) public virtual override returns (bool) {
    _transfer(sender, recipient, amount);
    _approve(sender, _msgSender(), _allowances[sender][_msgSender()] - amount);
    return true;
  }

  /**
   * @dev Atomically increases the allowance granted to `spender` by the caller.
   *
   * This is an alternative to {approve} that can be used as a mitigation for
   * problems described in {IERC20-approve}.
   *
   * Emits an {Approval} event indicating the updated allowance.
   *
   * Requirements:
   *
   * - `spender` cannot be the zero address.
   */
  function increaseAllowance(address spender, uint256 addedValue) public virtual returns (bool) {
    _approve(_msgSender(), spender, _allowances[_msgSender()][spender] + addedValue);
    return true;
  }

  /**
   * @dev Atomically decreases the allowance granted to `spender` by the caller.
   *
   * This is an alternative to {approve} that can be used as a mitigation for
   * problems described in {IERC20-approve}.
   *
   * Emits an {Approval} event indicating the updated allowance.
   *
   * Requirements:
   *
   * - `spender` cannot be the zero address.
   * - `spender` must have allowance for the caller of at least
   * `subtractedValue`.
   */
  function decreaseAllowance(address spender, uint256 subtractedValue)
    public
    virtual
    returns (bool)
  {
    _approve(_msgSender(), spender, _allowances[_msgSender()][spender] - subtractedValue);
    return true;
  }

  /**
   * @dev Moves tokens `amount` from `sender` to `recipient`.
   *
   * This is internal function is equivalent to {transfer}, and can be used to
   * e.g. implement automatic token fees, slashing mechanisms, etc.
   *
   * Emits a {Transfer} event.
   *
   * Requirements:
   *
   * - `sender` cannot be the zero address.
   * - `recipient` cannot be the zero address.
   * - `sender` must have a balance of at least `amount`.
   */
  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);

    _balances[sender] -= amount;
    _balances[recipient] += amount;
    emit Transfer(sender, recipient, amount);
  }

  /** @dev Creates `amount` tokens and assigns them to `account`, increasing
   * the total supply.
   *
   * Emits a {Transfer} event with `from` set to the zero address.
   *
   * Requirements
   *
   * - `to` cannot be the zero address.
   */
  function _mint(address account, uint256 amount) internal virtual {
    require(account != address(0), 'ERC20: mint to the zero address');

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

    _totalSupply += amount;
    _balances[account] += amount;
    emit Transfer(address(0), account, amount);
  }

  /**
   * @dev Destroys `amount` tokens from `account`, reducing the
   * total supply.
   *
   * Emits a {Transfer} event with `to` set to the zero address.
   *
   * Requirements
   *
   * - `account` cannot be the zero address.
   * - `account` must have at least `amount` tokens.
   */
  function _burn(address account, uint256 amount) internal virtual {
    require(account != address(0), 'ERC20: burn from the zero address');

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

    _balances[account] -= amount;
    _totalSupply -= amount;
    emit Transfer(account, address(0), amount);
  }

  /**
   * @dev Sets `amount` as the allowance of `spender` over the `owner`s tokens.
   *
   * This is internal function is equivalent to `approve`, and can be used to
   * e.g. set automatic allowances for certain subsystems, etc.
   *
   * Emits an {Approval} event.
   *
   * Requirements:
   *
   * - `owner` cannot be the zero address.
   * - `spender` cannot be the zero address.
   */
  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);
  }

  /**
   * @dev Sets {decimals} to a value other than the default one of 18.
   *
   * WARNING: This function should only be called from the constructor. Most
   * applications that interact with token contracts will not expect
   * {decimals} to ever change, and may work incorrectly if it does.
   */
  function _setupDecimals(uint8 decimals_) internal {
    _decimals = decimals_;
  }

  /**
   * @dev Hook that is called before any transfer of tokens. This includes
   * minting and burning.
   *
   * Calling conditions:
   *
   * - when `from` and `to` are both non-zero, `amount` of ``from``'s tokens
   * will be to transferred to `to`.
   * - when `from` is zero, `amount` tokens will be minted for `to`.
   * - when `to` is zero, `amount` of ``from``'s tokens will be burned.
   * - `from` and `to` are never both zero.
   *
   * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
   */
  function _beforeTokenTransfer(
    address from,
    address to,
    uint256 amount
  ) internal virtual {}
}

// File: contracts/dependencies/openzeppelin/contracts/Ownable.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

import './Context.sol';

/**
 * @dev Contract module which provides a basic access control mechanism, where
 * there is an account (an owner) that can be granted exclusive access to
 * specific functions.
 *
 * By default, the owner account will be the one that deploys the contract. This
 * can later be changed with {transferOwnership}.
 *
 * This module is used through inheritance. It will make available the modifier
 * `onlyOwner`, which can be applied to your functions to restrict their use to
 * the owner.
 */
contract Ownable is Context {
  address private _owner;

  event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);

  /**
   * @dev Initializes the contract setting the deployer as the initial owner.
   */
  constructor() {
    address msgSender = _msgSender();
    _owner = msgSender;
    emit OwnershipTransferred(address(0), msgSender);
  }

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

  /**
   * @dev Throws if called by any account other than the owner.
   */
  modifier onlyOwner() {
    require(_owner == _msgSender(), 'Ownable: caller is not the owner');
    _;
  }

  /**
   * @dev Leaves the contract without owner. It will not be possible to call
   * `onlyOwner` functions anymore. Can only be called by the current owner.
   *
   * NOTE: Renouncing ownership will leave the contract without an owner,
   * thereby removing any functionality that is only available to the owner.
   */
  function renounceOwnership() public payable virtual onlyOwner {
    emit OwnershipTransferred(_owner, address(0));
    _owner = address(0);
  }

  /**
   * @dev Transfers ownership of the contract to a new account (`newOwner`).
   * Can only be called by the current owner.
   */
  function transferOwnership(address newOwner) public payable virtual onlyOwner {
    require(newOwner != address(0), 'Ownable: new owner is the zero address');
    emit OwnershipTransferred(_owner, newOwner);
    _owner = newOwner;
  }
}

// File: contracts/dependencies/openzeppelin/contracts/Context.sol



// 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 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) {
    return msg.sender;
  }

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