Cryo Explorer Ethereum Mainnet

// SPDX-License-Identifier: agpl-3.0
pragma solidity ^0.7.5;

/// @title Optimized overflow and underflow safe math operations
/// @notice Contains methods for doing math operations that revert on overflow or underflow for minimal gas cost
/// inspired by uniswap V3
library SafeMath {
    /// @notice Returns x + y, reverts if sum overflows uint256
    /// @param x The augend
    /// @param y The addend
    /// @return z The sum of x and y
    function add(uint256 x, uint256 y) internal pure returns (uint256 z) {
        require((z = x + y) >= x);
    }

    /// @notice Returns x - y, reverts if underflows
    /// @param x The minuend
    /// @param y The subtrahend
    /// @return z The difference of x and y
    function sub(uint256 x, uint256 y) internal pure returns (uint256 z) {
        require((z = x - y) <= x);
    }

    /// @notice Returns x * y, reverts if overflows
    /// @param x The multiplicand
    /// @param y The multiplier
    /// @return z The product of x and y
    function mul(uint256 x, uint256 y) internal pure returns (uint256 z) {
        require(x == 0 || (z = x * y) / x == y);
    }

    function div(uint256 x, uint256 y) internal pure returns(uint256) {
        // no need to check for division by zero - solidity already reverts
        return x / y;
    }
}

// SPDX-License-Identifier: agpl-3.0
pragma solidity 0.7.5;
pragma experimental ABIEncoderV2;

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

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

// SPDX-License-Identifier: MIT
pragma solidity 0.7.5;

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

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

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

// SPDX-License-Identifier: agpl-3.0
pragma solidity 0.7.5;

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

    return c;
  }

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

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

    return c;
  }

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

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

    return c;
  }

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

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

    return c;
  }

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

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

// SPDX-License-Identifier: MIT

pragma solidity 0.7.5;

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

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

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

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

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

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

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

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

// SPDX-License-Identifier: agpl-3.0
pragma solidity 0.7.5;
pragma experimental ABIEncoderV2;

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

/**
 * @title DistributionManager
 * @notice Accounting contract to manage multiple staking distributions
 * @author Aave
 **/
contract DistributionManager is IAaveDistributionManager {
  using SafeMath for uint256;

  struct AssetData {
    uint104 emissionPerSecond;
    uint104 index;
    uint40 lastUpdateTimestamp;
    mapping(address => uint256) users;
  }

  address public immutable EMISSION_MANAGER;

  uint8 public 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 IAaveDistributionManager
  function setDistributionEnd(uint256 distributionEnd) external override onlyEmissionManager {
    _distributionEnd = distributionEnd;
    emit DistributionEndUpdated(distributionEnd);
  }

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

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

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

  /// @inheritdoc IAaveDistributionManager
  function getAssetData(address asset) public view 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
  {
    for (uint256 i = 0; i < assetsConfigInput.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) {
      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);
    } else {
      assetConfig.lastUpdateTimestamp = uint40(block.timestamp);
    }

    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 = 0;

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

    if (userIndex != newIndex) {
      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 = 0;

    for (uint256 i = 0; i < stakes.length; i++) {
      accruedRewards = accruedRewards.add(
        _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 = 0;

    for (uint256 i = 0; i < stakes.length; i++) {
      AssetData storage assetConfig = assets[stakes[i].underlyingAsset];
      uint256 assetIndex =
        _getAssetIndex(
          assetConfig.index,
          assetConfig.emissionPerSecond,
          assetConfig.lastUpdateTimestamp,
          stakes[i].totalStaked
        );

      accruedRewards = accruedRewards.add(
        _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.mul(reserveIndex.sub(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.sub(lastUpdateTimestamp);
    return
      emissionPerSecond.mul(timeDelta).mul(10**uint256(PRECISION)).div(totalBalance).add(
        currentIndex
      );
  }
}

// SPDX-License-Identifier: agpl-3.0
pragma solidity 0.7.5;

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

// SPDX-License-Identifier: AGPL-3.0
pragma solidity 0.7.5;

import {IStakedToken} from '@aave/aave-stake/contracts/interfaces/IStakedToken.sol';

interface IStakedTokenWithConfig is IStakedToken {
  function STAKED_TOKEN() external view returns(address);
}

// SPDX-License-Identifier: MIT
pragma solidity 0.7.5;

/**
 * @dev Interface of the ERC20 standard as defined in the EIP.
 * From https://github.com/OpenZeppelin/openzeppelin-contracts
 */
interface IERC20 {
  /**
   * @dev Returns the amount of tokens in existence.
   */
  function totalSupply() external view returns (uint256);

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

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

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

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

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

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

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

// SPDX-License-Identifier: agpl-3.0
pragma solidity 0.7.5;
pragma experimental ABIEncoderV2;

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

interface IAaveDistributionManager {
  
  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;

  /**
  * @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);
}

// SPDX-License-Identifier: agpl-3.0
pragma solidity 0.7.5;

pragma experimental ABIEncoderV2;

import {IAaveDistributionManager} from '../interfaces/IAaveDistributionManager.sol';

interface IAaveIncentivesController is IAaveDistributionManager {
  
  event RewardsAccrued(address indexed user, uint256 amount);
  
  event RewardsClaimed(
    address indexed user,
    address indexed to,
    address indexed claimer,
    uint256 amount
  );

  event ClaimerSet(address indexed user, address indexed claimer);

  /**
   * @dev Whitelists an address to claim the rewards on behalf of another address
   * @param user The address of the user
   * @param claimer The address of the claimer
   */
  function setClaimer(address user, address claimer) external;

  /**
   * @dev Returns the whitelisted claimer for a certain address (0x0 if not set)
   * @param user The address of the user
   * @return The claimer address
   */
  function getClaimer(address user) external view returns (address);

  /**
   * @dev Configure assets for a certain rewards emission
   * @param assets The assets to incentivize
   * @param emissionsPerSecond The emission for each asset
   */
  function configureAssets(address[] calldata assets, uint256[] calldata emissionsPerSecond)
    external;


  /**
   * @dev Called by the corresponding asset on any update that affects the rewards distribution
   * @param asset The address of the user
   * @param userBalance The balance of the user of the asset in the lending pool
   * @param totalSupply The total supply of the asset in the lending pool
   **/
  function handleAction(
    address asset,
    uint256 userBalance,
    uint256 totalSupply
  ) external;

  /**
   * @dev Returns the total of rewards of an user, already accrued + not yet accrued
   * @param user The address of the user
   * @return The rewards
   **/
  function getRewardsBalance(address[] calldata assets, address user)
    external
    view
    returns (uint256);

  /**
   * @dev Claims reward for an user, on all the assets of the lending pool, accumulating the pending rewards
   * @param amount Amount of rewards to claim
   * @param to Address that will be receiving the rewards
   * @return Rewards claimed
   **/
  function claimRewards(
    address[] calldata assets,
    uint256 amount,
    address to
  ) external returns (uint256);

  /**
   * @dev Claims reward for an user on behalf, on all the assets of the lending pool, accumulating the pending rewards. The caller must
   * be whitelisted via "allowClaimOnBehalf" function by the RewardsAdmin role manager
   * @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 claimRewardsOnBehalf(
    address[] calldata assets,
    uint256 amount,
    address user,
    address to
  ) external returns (uint256);

  /**
   * @dev Claims rewards for a user, on the specified assets of the lending pool, distributing the pending rewards to self
   * @param assets Incentivized assets on which to claim rewards
   * @param amount Amount of rewards to claim
   * @return Rewards claimed
   **/
  function claimRewardsToSelf(address[] calldata assets, uint256 amount) external returns (uint256);

  /**
   * @dev returns the unclaimed rewards of the user
   * @param user the address of the user
   * @return the unclaimed user rewards
   */
  function getUserUnclaimedRewards(address user) external view returns (uint256);

  /**
  * @dev for backward compatibility with previous implementation of the Incentives controller
  */
  function REWARD_TOKEN() external view returns (address);
}

// SPDX-License-Identifier: agpl-3.0
pragma solidity 0.7.5;

interface IStakedToken {
  
  function stake(address to, uint256 amount) external;

  function redeem(address to, uint256 amount) external;

  function cooldown() external;

  function claimRewards(address to, uint256 amount) external;
}

// SPDX-License-Identifier: agpl-3.0
pragma solidity 0.7.5;
pragma experimental ABIEncoderV2;

import {SafeERC20} from '@aave/aave-stake/contracts/lib/SafeERC20.sol';
import {SafeMath} from '../lib/SafeMath.sol';
import {DistributionTypes} from '../lib/DistributionTypes.sol';
import {VersionedInitializable} from '@aave/aave-stake/contracts/utils/VersionedInitializable.sol';
import {DistributionManager} from './DistributionManager.sol';
import {IStakedTokenWithConfig} from '../interfaces/IStakedTokenWithConfig.sol';
import {IERC20} from '@aave/aave-stake/contracts/interfaces/IERC20.sol';
import {IScaledBalanceToken} from '../interfaces/IScaledBalanceToken.sol';
import {IAaveIncentivesController} from '../interfaces/IAaveIncentivesController.sol';

/**
 * @title StakedTokenIncentivesController
 * @notice Distributor contract for rewards to the Aave protocol, using a staked token as rewards asset.
 * The contract stakes the rewards before redistributing them to the Aave protocol participants.
 * The reference staked token implementation is at https://github.com/aave/aave-stake-v2
 * @author Aave
 **/
contract StakedTokenIncentivesController is
  IAaveIncentivesController,
  VersionedInitializable,
  DistributionManager
{
  using SafeMath for uint256;
  using SafeERC20 for IERC20;

  uint256 public constant REVISION = 2;

  IStakedTokenWithConfig public immutable STAKE_TOKEN;

  mapping(address => uint256) internal _usersUnclaimedRewards;

  // this mapping allows whitelisted addresses to claim on behalf of others
  // useful for contracts that hold tokens to be rewarded but don't have any native logic to claim Liquidity Mining rewards
  mapping(address => address) internal _authorizedClaimers;

  modifier onlyAuthorizedClaimers(address claimer, address user) {
    require(_authorizedClaimers[user] == claimer, 'CLAIMER_UNAUTHORIZED');
    _;
  }

  constructor(IStakedTokenWithConfig stakeToken, address emissionManager)
    DistributionManager(emissionManager)
  {
    STAKE_TOKEN = stakeToken;
  }

  /**
   * @dev Initialize IStakedTokenIncentivesController. Empty after REVISION 1, but maintains the expected interface.
   **/
  function initialize(address) external initializer {}

  /// @inheritdoc IAaveIncentivesController
  function configureAssets(address[] calldata assets, uint256[] calldata emissionsPerSecond)
    external
    override
    onlyEmissionManager
  {
    require(assets.length == emissionsPerSecond.length, 'INVALID_CONFIGURATION');

    DistributionTypes.AssetConfigInput[] memory assetsConfig =
      new DistributionTypes.AssetConfigInput[](assets.length);

    for (uint256 i = 0; i < assets.length; i++) {
      assetsConfig[i].underlyingAsset = assets[i];
      assetsConfig[i].emissionPerSecond = uint104(emissionsPerSecond[i]);

      require(assetsConfig[i].emissionPerSecond == emissionsPerSecond[i], 'INVALID_CONFIGURATION');

      assetsConfig[i].totalStaked = IScaledBalanceToken(assets[i]).scaledTotalSupply();
    }
    _configureAssets(assetsConfig);
  }

  /// @inheritdoc IAaveIncentivesController
  function handleAction(
    address user,
    uint256 totalSupply,
    uint256 userBalance
  ) external override {
    uint256 accruedRewards = _updateUserAssetInternal(user, msg.sender, userBalance, totalSupply);
    if (accruedRewards != 0) {
      _usersUnclaimedRewards[user] = _usersUnclaimedRewards[user].add(accruedRewards);
      emit RewardsAccrued(user, accruedRewards);
    }
  }

  /// @inheritdoc IAaveIncentivesController
  function getRewardsBalance(address[] calldata assets, address user)
    external
    view
    override
    returns (uint256)
  {
    uint256 unclaimedRewards = _usersUnclaimedRewards[user];

    DistributionTypes.UserStakeInput[] memory userState =
      new DistributionTypes.UserStakeInput[](assets.length);
    for (uint256 i = 0; i < assets.length; i++) {
      userState[i].underlyingAsset = assets[i];
      (userState[i].stakedByUser, userState[i].totalStaked) = IScaledBalanceToken(assets[i])
        .getScaledUserBalanceAndSupply(user);
    }
    unclaimedRewards = unclaimedRewards.add(_getUnclaimedRewards(user, userState));
    return unclaimedRewards;
  }

  /// @inheritdoc IAaveIncentivesController
  function claimRewards(
    address[] calldata assets,
    uint256 amount,
    address to
  ) external override returns (uint256) {
    require(to != address(0), 'INVALID_TO_ADDRESS');
    return _claimRewards(assets, amount, msg.sender, msg.sender, to);
  }

  /// @inheritdoc IAaveIncentivesController
  function claimRewardsOnBehalf(
    address[] calldata assets,
    uint256 amount,
    address user,
    address to
  ) external override onlyAuthorizedClaimers(msg.sender, user) returns (uint256) {
    require(user != address(0), 'INVALID_USER_ADDRESS');
    require(to != address(0), 'INVALID_TO_ADDRESS');
    return _claimRewards(assets, amount, msg.sender, user, to);
  }

  /// @inheritdoc IAaveIncentivesController
  function claimRewardsToSelf(address[] calldata assets, uint256 amount)
    external
    override
    returns (uint256)
  {
    return _claimRewards(assets, amount, msg.sender, msg.sender, msg.sender);
  }

  /**
   * @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
   **/

  /// @inheritdoc IAaveIncentivesController
  function setClaimer(address user, address caller) external override onlyEmissionManager {
    _authorizedClaimers[user] = caller;
    emit ClaimerSet(user, caller);
  }

  /// @inheritdoc IAaveIncentivesController
  function getClaimer(address user) external view override returns (address) {
    return _authorizedClaimers[user];
  }

  /// @inheritdoc IAaveIncentivesController
  function getUserUnclaimedRewards(address _user) external view override returns (uint256) {
    return _usersUnclaimedRewards[_user];
  }

  /// @inheritdoc IAaveIncentivesController
  function REWARD_TOKEN() external view override returns (address) {
    return address(STAKE_TOKEN);
  }

  /**
   * @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[] calldata assets,
    uint256 amount,
    address claimer,
    address user,
    address to
  ) internal returns (uint256) {
    if (amount == 0) {
      return 0;
    }
    uint256 unclaimedRewards = _usersUnclaimedRewards[user];

    DistributionTypes.UserStakeInput[] memory userState =
      new DistributionTypes.UserStakeInput[](assets.length);
    for (uint256 i = 0; i < assets.length; i++) {
      userState[i].underlyingAsset = assets[i];
      (userState[i].stakedByUser, userState[i].totalStaked) = IScaledBalanceToken(assets[i])
        .getScaledUserBalanceAndSupply(user);
    }

    uint256 accruedRewards = _claimRewards(user, userState);
    if (accruedRewards != 0) {
      unclaimedRewards = unclaimedRewards.add(accruedRewards);
      emit RewardsAccrued(user, accruedRewards);
    }

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

    uint256 amountToClaim = amount > unclaimedRewards ? unclaimedRewards : amount;
    _usersUnclaimedRewards[user] = unclaimedRewards - amountToClaim; // Safe due to the previous line

    STAKE_TOKEN.stake(to, amountToClaim);
    emit RewardsClaimed(user, to, claimer, amountToClaim);

    return amountToClaim;
  }
}

// SPDX-License-Identifier: agpl-3.0
pragma solidity 0.7.5;

/**
 * @title VersionedInitializable
 *
 * @dev Helper contract to support 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 Aave, inspired by the OpenZeppelin Initializable contract
 */
abstract contract VersionedInitializable {
  /**
   * @dev Indicates that the contract has been initialized.
   */
  uint256 internal lastInitializedRevision = 0;

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

    lastInitializedRevision = revision;

    _;
  }

  /// @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);

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