StakedTokenV3

{{
  "language": "Solidity",
  "sources": {
    "contracts/StakedTokenV3.sol": {
      "content": "// SPDX-License-Identifier: MIT
// File contracts/stake/StakedTokenV3.sol
/**
 * @title StakedToken
 * @notice Contract to stake Aave token, tokenize the position and get rewards, inheriting from a distribution manager contract
 * @author Aave
 **/

pragma solidity 0.7.5;
pragma experimental ABIEncoderV2;

import "./helper/ReentrancyGuardUpgradeable.sol";
import "./AaveDistributionManager.sol";
import "./interface/IERC20.sol";
import "./interface/IGovernancePowerDelegationToken.sol";
import "./interface/ITransferHook.sol";
import "./interface/IStakedAave.sol";
import "./helper/Context.sol";
import "./helper/GovernancePowerWithSnapshot.sol";
import "./helper/GovernancePowerDelegationERC20.sol";
import "./helper/VersionedInitializable.sol";
import "./helper/ERC2771Context.sol";
import "./lib/SafeERC20.sol";

/**
 * @title StakedToken V3
 * @notice Contract to stake Aave token, tokenize the position and get rewards, inheriting from a distribution manager contract
 * @author Aave
 **/
contract StakedTokenV3 is
  IStakedAave,
  GovernancePowerWithSnapshot,
  VersionedInitializable,
  AaveDistributionManager,
  ERC2771Context,
  ReentrancyGuardUpgradeable
{
  using SafeMath for uint256;
  using SafeERC20 for IERC20;

  /// @dev Start of Storage layout from StakedToken v1
  uint256 public constant REVISION = 1;

  IERC20 public immutable STAKED_TOKEN;
  IERC20 public immutable REWARD_TOKEN;
  uint256 public immutable COOLDOWN_SECONDS;

  /// @notice Seconds available to redeem once the cooldown period is fullfilled
  uint256 public immutable UNSTAKE_WINDOW;

  /// @notice Address to pull from the rewards, needs to have approved this contract
  address public immutable REWARDS_VAULT;

  mapping(address => uint256) public stakerRewardsToClaim;
  mapping(address => uint256) public stakersCooldowns;

  /// @dev End of Storage layout from StakedToken v1

  /// @dev To see the voting mappings, go to GovernancePowerWithSnapshot.sol
  mapping(address => address) internal _votingDelegates;

  mapping(address => mapping(uint256 => Snapshot)) internal _propositionPowerSnapshots;
  mapping(address => uint256) internal _propositionPowerSnapshotsCounts;
  mapping(address => address) internal _propositionPowerDelegates;

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

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

  event Staked(address indexed from, address indexed onBehalfOf, uint256 amount);
  event Redeem(address indexed from, address indexed to, uint256 amount);

  event RewardsAccrued(address user, uint256 amount);
  event RewardsClaimed(address indexed from, address indexed to, uint256 amount);

  event Cooldown(address indexed user);

  constructor(
    IERC20 stakedToken,
    IERC20 rewardToken,
    uint256 cooldownSeconds,
    uint256 unstakeWindow,
    address rewardsVault,
    address emissionManager,
    uint128 distributionDuration,
    string memory name,
    string memory symbol,
    uint8 decimals,
    address governance
  ) public ERC20(name, symbol) AaveDistributionManager(emissionManager, distributionDuration) {
    require(address(stakedToken) != address(0), "STAKED_TOKEN_ADDRESS_CANNOT_BE_ZERO");
    require(address(rewardToken) != address(0), "REWARD_TOKEN_ADDRESS_CANNOT_BE_ZERO");
    require(rewardsVault != address(0), "REWARD_VAULT_ADDRESS_CANNOT_BE_ZERO");
    STAKED_TOKEN = stakedToken;
    REWARD_TOKEN = rewardToken;
    COOLDOWN_SECONDS = cooldownSeconds;
    UNSTAKE_WINDOW = unstakeWindow;
    REWARDS_VAULT = rewardsVault;
    _aaveGovernance = ITransferHook(governance);
    ERC20._setupDecimals(decimals);
  }

  /**
   * @dev Called by the proxy contract
   **/
  function initialize(
    string calldata name,
    string calldata symbol,
    uint8 decimals,
    address _trustedForwarder
  ) external {
    require(_trustedForwarder != address(0), "TrustForwarder address can't be 0");
    initializeTrustedForwarder(_trustedForwarder);

    __ReentrancyGuard_init();

    uint256 chainId;

    //solium-disable-next-line
    assembly {
      chainId := chainid()
    }

    DOMAIN_SEPARATOR = keccak256(
      abi.encode(
        EIP712_DOMAIN,
        keccak256(bytes(super.name())),
        keccak256(EIP712_REVISION),
        chainId,
        address(this)
      )
    );

    
    if (REVISION == 1) {
      _name = name;
      _symbol = symbol;
      _setupDecimals(decimals);
    }
  }

  function _msgSender() internal view override(ERC2771Context, Context) returns (address payable sender) {
    return ERC2771Context._msgSender();
  }

  function _msgData() internal view override(ERC2771Context, Context) returns (bytes calldata) {
    return ERC2771Context._msgData();
  }

  function stake(address onBehalfOf, uint256 amount) external override {
    require(amount != 0, 'INVALID_ZERO_AMOUNT');
    uint256 balanceOfUser = balanceOf(onBehalfOf);

    uint256 accruedRewards =
      _updateUserAssetInternal(onBehalfOf, address(this), balanceOfUser, totalSupply());
    if (accruedRewards != 0) {
      emit RewardsAccrued(onBehalfOf, accruedRewards);
      stakerRewardsToClaim[onBehalfOf] = stakerRewardsToClaim[onBehalfOf].add(accruedRewards);
    }

    stakersCooldowns[onBehalfOf] = getNextCooldownTimestamp(0, amount, onBehalfOf, balanceOfUser);

    _mint(onBehalfOf, amount);
    IERC20(STAKED_TOKEN).safeTransferFrom(_msgSender(), address(this), amount);

    emit Staked(_msgSender(), onBehalfOf, amount);
  }

  function immediatelyRedeemAll(address to) public nonReentrant {
    uint256 balanceOfMessageSender = balanceOf(_msgSender());

    _updateCurrentUnclaimedRewards(_msgSender(), balanceOfMessageSender, true);

    _burn(_msgSender(), balanceOfMessageSender);

    stakersCooldowns[_msgSender()] = 0;

    IERC20(STAKED_TOKEN).safeTransfer(to, balanceOfMessageSender);

    emit Redeem(_msgSender(), to, balanceOfMessageSender);
  }

  /**
   * @dev Redeems staked tokens, and stop earning rewards
   * @param to Address to redeem to
   * @param amount Amount to redeem
   **/
  function redeem(address to, uint256 amount) external override nonReentrant {
    require(amount != 0, 'INVALID_ZERO_AMOUNT');
    //solium-disable-next-line
    
    uint256 cooldownStartTimestamp = stakersCooldowns[_msgSender()];
    
    require(
      block.timestamp > cooldownStartTimestamp.add(COOLDOWN_SECONDS),
      'INSUFFICIENT_COOLDOWN'
    );
    require(
      block.timestamp.sub(cooldownStartTimestamp.add(COOLDOWN_SECONDS)) <= UNSTAKE_WINDOW,
      'UNSTAKE_WINDOW_FINISHED'
    );
    
    uint256 balanceOfMessageSender = balanceOf(_msgSender());

    uint256 amountToRedeem = (amount > balanceOfMessageSender) ? balanceOfMessageSender : amount;

    _updateCurrentUnclaimedRewards(_msgSender(), balanceOfMessageSender, true);

    _burn(_msgSender(), amountToRedeem);

    if (balanceOfMessageSender.sub(amountToRedeem) == 0) {
      stakersCooldowns[_msgSender()] = 0;
    }

    IERC20(STAKED_TOKEN).safeTransfer(to, amountToRedeem);

    emit Redeem(_msgSender(), to, amountToRedeem);
  }

  /**
   * @dev Activates the cooldown period to unstake
   * - It can't be called if the user is not staking
   **/
  function cooldown() external override {
    require(balanceOf(_msgSender()) != 0, 'INVALID_BALANCE_ON_COOLDOWN');
    //solium-disable-next-line
    stakersCooldowns[_msgSender()] = block.timestamp;

    emit Cooldown(_msgSender());
  }

  /**
   * @dev Claims an `amount` of `REWARD_TOKEN` to the address `to`
   * @param to Address to stake for
   * @param amount Amount to stake
   **/
  function claimRewards(address to, uint256 amount) external override nonReentrant {
    uint256 newTotalRewards =
      _updateCurrentUnclaimedRewards(_msgSender(), balanceOf(_msgSender()), false);
    uint256 amountToClaim = (amount == type(uint256).max) ? newTotalRewards : amount;

    stakerRewardsToClaim[_msgSender()] = newTotalRewards.sub(amountToClaim, 'INVALID_AMOUNT');

    REWARD_TOKEN.safeTransferFrom(REWARDS_VAULT, to, amountToClaim);

    emit RewardsClaimed(_msgSender(), to, amountToClaim);
  }

  /**
   * @dev Internal ERC20 _transfer of the tokenized staked tokens
   * @param from Address to transfer from
   * @param to Address to transfer to
   * @param amount Amount to transfer
   **/
  function _transfer(
    address from,
    address to,
    uint256 amount
  ) internal override {
    uint256 balanceOfFrom = balanceOf(from);
    // Sender
    _updateCurrentUnclaimedRewards(from, balanceOfFrom, true);

    // Recipient
    if (from != to) {
      uint256 balanceOfTo = balanceOf(to);
      _updateCurrentUnclaimedRewards(to, balanceOfTo, true);

      uint256 previousSenderCooldown = stakersCooldowns[from];
      stakersCooldowns[to] = getNextCooldownTimestamp(
        previousSenderCooldown,
        amount,
        to,
        balanceOfTo
      );
      // if cooldown was set and whole balance of sender was transferred - clear cooldown
      if (balanceOfFrom == amount && previousSenderCooldown != 0) {
        stakersCooldowns[from] = 0;
      }
    }

    super._transfer(from, to, amount);
  }

  /**
   * @dev Updates the user state related with his accrued rewards
   * @param user Address of the user
   * @param userBalance The current balance of the user
   * @param updateStorage Boolean flag used to update or not the stakerRewardsToClaim of the user
   * @return The unclaimed rewards that were added to the total accrued
   **/
  function _updateCurrentUnclaimedRewards(
    address user,
    uint256 userBalance,
    bool updateStorage
  ) internal returns (uint256) {
    uint256 accruedRewards =
      _updateUserAssetInternal(user, address(this), userBalance, totalSupply());
    uint256 unclaimedRewards = stakerRewardsToClaim[user].add(accruedRewards);

    if (accruedRewards != 0) {
      if (updateStorage) {
        stakerRewardsToClaim[user] = unclaimedRewards;
      }
      emit RewardsAccrued(user, accruedRewards);
    }

    return unclaimedRewards;
  }

  /**
   * @dev Calculates the how is gonna be a new cooldown timestamp depending on the sender/receiver situation
   *  - If the timestamp of the sender is "better" or the timestamp of the recipient is 0, we take the one of the recipient
   *  - Weighted average of from/to cooldown timestamps if:
   *    # The sender doesn't have the cooldown activated (timestamp 0).
   *    # The sender timestamp is expired
   *    # The sender has a "worse" timestamp
   *  - If the receiver's cooldown timestamp expired (too old), the next is 0
   * @param fromCooldownTimestamp Cooldown timestamp of the sender
   * @param amountToReceive Amount
   * @param toAddress Address of the recipient
   * @param toBalance Current balance of the receiver
   * @return The new cooldown timestamp
   **/
  function getNextCooldownTimestamp(
    uint256 fromCooldownTimestamp,
    uint256 amountToReceive,
    address toAddress,
    uint256 toBalance
  ) public view returns (uint256) {
    uint256 toCooldownTimestamp = stakersCooldowns[toAddress];
    if (toCooldownTimestamp == 0) {
      return 0;
    }

    uint256 minimalValidCooldownTimestamp =
      block.timestamp.sub(COOLDOWN_SECONDS).sub(UNSTAKE_WINDOW);

    if (minimalValidCooldownTimestamp > toCooldownTimestamp) {
      toCooldownTimestamp = 0;
    } else {
      uint256 fromCooldownTimestamp =
        (minimalValidCooldownTimestamp > fromCooldownTimestamp)
          ? block.timestamp
          : fromCooldownTimestamp;

      if (fromCooldownTimestamp < toCooldownTimestamp) {
        return toCooldownTimestamp;
      } else {
        toCooldownTimestamp = (
          amountToReceive.mul(fromCooldownTimestamp).add(toBalance.mul(toCooldownTimestamp))
        )
          .div(amountToReceive.add(toBalance));
      }
    }
    return toCooldownTimestamp;
  }

  /**
   * @dev Return the total rewards pending to claim by an staker
   * @param staker The staker address
   * @return The rewards
   */
  function getTotalRewardsBalance(address staker) external view returns (uint256) {
    DistributionTypes.UserStakeInput[] memory userStakeInputs =
      new DistributionTypes.UserStakeInput[](1);
    userStakeInputs[0] = DistributionTypes.UserStakeInput({
      underlyingAsset: address(this),
      stakedByUser: balanceOf(staker),
      totalStaked: totalSupply()
    });
    return stakerRewardsToClaim[staker].add(_getUnclaimedRewards(staker, userStakeInputs));
  }

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

  /**
   * @dev implements the permit function as for https://github.com/ethereum/EIPs/blob/8a34d644aacf0f9f8f00815307fd7dd5da07655f/EIPS/eip-2612.md
   * @param owner the owner of the funds
   * @param spender the spender
   * @param value the amount
   * @param deadline the deadline timestamp, type(uint256).max for no deadline
   * @param v signature param
   * @param s signature param
   * @param r signature param
   */

  function permit(
    address owner,
    address spender,
    uint256 value,
    uint256 deadline,
    uint8 v,
    bytes32 r,
    bytes32 s
  ) external {
    require(owner != address(0), 'INVALID_OWNER');
    //solium-disable-next-line
    require(block.timestamp <= deadline, 'INVALID_EXPIRATION');
    uint256 currentValidNonce = _nonces[owner];
    bytes32 digest =
      keccak256(
        abi.encodePacked(
          '\x19\x01',
          DOMAIN_SEPARATOR,
          keccak256(abi.encode(PERMIT_TYPEHASH, owner, spender, value, currentValidNonce, deadline))
        )
      );

    require(owner == ecrecover(digest, v, r, s), 'INVALID_SIGNATURE');
    _nonces[owner] = currentValidNonce.add(1);
    _approve(owner, spender, value);
  }

  /**
   * @dev Writes a snapshot before any operation involving transfer of value: _transfer, _mint and _burn
   * - On _transfer, it writes snapshots for both "from" and "to"
   * - On _mint, only for _to
   * - On _burn, only for _from
   * @param from the from address
   * @param to the to address
   * @param amount the amount to transfer
   */
  function _beforeTokenTransfer(
    address from,
    address to,
    uint256 amount
  ) internal override {
    address votingFromDelegatee = _votingDelegates[from];
    address votingToDelegatee = _votingDelegates[to];

    if (votingFromDelegatee == address(0)) {
      votingFromDelegatee = from;
    }
    if (votingToDelegatee == address(0)) {
      votingToDelegatee = to;
    }

    _moveDelegatesByType(
      votingFromDelegatee,
      votingToDelegatee,
      amount,
      DelegationType.VOTING_POWER
    );

    address propPowerFromDelegatee = _propositionPowerDelegates[from];
    address propPowerToDelegatee = _propositionPowerDelegates[to];

    if (propPowerFromDelegatee == address(0)) {
      propPowerFromDelegatee = from;
    }
    if (propPowerToDelegatee == address(0)) {
      propPowerToDelegatee = to;
    }

    _moveDelegatesByType(
      propPowerFromDelegatee,
      propPowerToDelegatee,
      amount,
      DelegationType.PROPOSITION_POWER
    );

    // caching the aave governance address to avoid multiple state loads
    ITransferHook aaveGovernance = _aaveGovernance;
    if (aaveGovernance != ITransferHook(0)) {
      aaveGovernance.onTransfer(from, to, amount);
    }
  }

  function _getDelegationDataByType(DelegationType delegationType)
    internal
    view
    override
    returns (
      mapping(address => mapping(uint256 => Snapshot)) storage, //snapshots
      mapping(address => uint256) storage, //snapshots count
      mapping(address => address) storage //delegatees list
    )
  {
    if (delegationType == DelegationType.VOTING_POWER) {
      return (_votingSnapshots, _votingSnapshotsCounts, _votingDelegates);
    } else {
      return (
        _propositionPowerSnapshots,
        _propositionPowerSnapshotsCounts,
        _propositionPowerDelegates
      );
    }
  }

  /**
   * @dev Delegates power from signatory to `delegatee`
   * @param delegatee The address to delegate votes to
   * @param delegationType the type of delegation (VOTING_POWER, PROPOSITION_POWER)
   * @param nonce The contract state required to match the signature
   * @param expiry The time at which to expire the signature
   * @param v The recovery byte of the signature
   * @param r Half of the ECDSA signature pair
   * @param s Half of the ECDSA signature pair
   */
  function delegateByTypeBySig(
    address delegatee,
    DelegationType delegationType,
    uint256 nonce,
    uint256 expiry,
    uint8 v,
    bytes32 r,
    bytes32 s
  ) external {
    bytes32 structHash =
      keccak256(
        abi.encode(DELEGATE_BY_TYPE_TYPEHASH, delegatee, uint256(delegationType), nonce, expiry)
      );
    bytes32 digest = keccak256(abi.encodePacked('\x19\x01', DOMAIN_SEPARATOR, structHash));
    address signatory = ecrecover(digest, v, r, s);
    require(signatory != address(0), 'INVALID_SIGNATURE');
    require(nonce == _nonces[signatory]++, 'INVALID_NONCE');
    require(block.timestamp <= expiry, 'INVALID_EXPIRATION');
    _delegateByType(signatory, delegatee, delegationType);
  }

  /**
   * @dev Delegates power from signatory to `delegatee`
   * @param delegatee The address to delegate votes to
   * @param nonce The contract state required to match the signature
   * @param expiry The time at which to expire the signature
   * @param v The recovery byte of the signature
   * @param r Half of the ECDSA signature pair
   * @param s Half of the ECDSA signature pair
   */
  function delegateBySig(
    address delegatee,
    uint256 nonce,
    uint256 expiry,
    uint8 v,
    bytes32 r,
    bytes32 s
  ) public {
    bytes32 structHash = keccak256(abi.encode(DELEGATE_TYPEHASH, delegatee, nonce, expiry));
    bytes32 digest = keccak256(abi.encodePacked('\x19\x01', DOMAIN_SEPARATOR, structHash));
    address signatory = ecrecover(digest, v, r, s);
    require(signatory != address(0), 'INVALID_SIGNATURE');
    require(nonce == _nonces[signatory]++, 'INVALID_NONCE');
    require(block.timestamp <= expiry, 'INVALID_EXPIRATION');
    _delegateByType(signatory, delegatee, DelegationType.VOTING_POWER);
    _delegateByType(signatory, delegatee, DelegationType.PROPOSITION_POWER);
  }
}"
    },
    "contracts/helper/ReentrancyGuardUpgradeable.sol": {
      "content": "//SPDX-License-Identifier: MIT

pragma solidity 0.7.5;
import "./Initializable.sol";

/**
 * @dev Contract module that helps prevent reentrant calls to a function.
 *
 * Inheriting from `ReentrancyGuard` will make the {nonReentrant} modifier
 * available, which can be applied to functions to make sure there are no nested
 * (reentrant) calls to them.
 *
 * Note that because there is a single `nonReentrant` guard, functions marked as
 * `nonReentrant` may not call one another. This can be worked around by making
 * those functions `private`, and then adding `external` `nonReentrant` entry
 * points to them.
 *
 * TIP: If you would like to learn more about reentrancy and alternative ways
 * to protect against it, check out our blog post
 * https://blog.openzeppelin.com/reentrancy-after-istanbul/[Reentrancy After Istanbul].
 */
abstract contract ReentrancyGuardUpgradeable is Initializable {
    // Booleans are more expensive than uint256 or any type that takes up a full
    // word because each write operation emits an extra SLOAD to first read the
    // slot's contents, replace the bits taken up by the boolean, and then write
    // back. This is the compiler's defense against contract upgrades and
    // pointer aliasing, and it cannot be disabled.

    // The values being non-zero value makes deployment a bit more expensive,
    // but in exchange the refund on every call to nonReentrant will be lower in
    // amount. Since refunds are capped to a percentage of the total
    // transaction's gas, it is best to keep them low in cases like this one, to
    // increase the likelihood of the full refund coming into effect.
    uint256 private constant _NOT_ENTERED = 1;
    uint256 private constant _ENTERED = 2;

    uint256 private _status;

    function __ReentrancyGuard_init() internal reentrancy_initializer {
        __ReentrancyGuard_init_unchained();
    }

    function __ReentrancyGuard_init_unchained() internal reentrancy_initializer {
        _status = _NOT_ENTERED;
    }

    /**
     * @dev Prevents a contract from calling itself, directly or indirectly.
     * Calling a `nonReentrant` function from another `nonReentrant`
     * function is not supported. It is possible to prevent this from happening
     * by making the `nonReentrant` function external, and make it call a
     * `private` function that does the actual work.
     */
    modifier nonReentrant() {
        // On the first call to nonReentrant, _notEntered will be true
        require(_status != _ENTERED, "ReentrancyGuard: reentrant call");

        // Any calls to nonReentrant after this point will fail
        _status = _ENTERED;

        _;

        // By storing the original value once again, a refund is triggered (see
        // https://eips.ethereum.org/EIPS/eip-2200)
        _status = _NOT_ENTERED;
    }
    uint256[49] private __gap;
}
"
    },
    "contracts/AaveDistributionManager.sol": {
      "content": "// SPDX-License-Identifier: MIT
// File contracts/stake/AaveDistributionManager.sol
pragma solidity 0.7.5;
pragma experimental ABIEncoderV2;
import "./DistributionTypes.sol";
import "./lib/SafeMath.sol";
import "./interface/IAaveDistributionManager.sol";

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

  struct AssetData {
    uint128 emissionPerSecond;
    uint128 lastUpdateTimestamp;
    uint256 index;
    mapping(address => uint256) users;
  }

  uint256 public immutable DISTRIBUTION_END;

  address public immutable EMISSION_MANAGER;

  mapping(address => AssetData) public assets;

  event AssetConfigUpdated(address indexed asset, uint256 emission);
  event AssetIndexUpdated(address indexed asset, uint256 index);
  event UserIndexUpdated(address indexed user, address indexed asset, uint256 index);

  constructor(address emissionManager, uint256 distributionDuration) public {
    require(emissionManager!=address(0), "EMMISSION_MANAGER_CANNOT_BE_ZERO");
    DISTRIBUTION_END = block.timestamp.add(distributionDuration);
    EMISSION_MANAGER = emissionManager;
  }

  /**
   * @dev Configures the distribution of rewards for a list of assets
   * @param assetsConfigInput The list of configurations to apply
   **/
  function configureAssets(DistributionTypes.AssetConfigInput[] calldata assetsConfigInput)
    external
    override
  {
    require(msg.sender == EMISSION_MANAGER, 'ONLY_EMISSION_MANAGER');

    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 underlyingAsset The address used as key in the distribution, for example sAAVE or the aTokens addresses on Aave
   * @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 underlyingAsset,
    AssetData storage assetConfig,
    uint256 totalStaked
  ) internal returns (uint256) {
    uint256 oldIndex = assetConfig.index;
    uint128 lastUpdateTimestamp = assetConfig.lastUpdateTimestamp;

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

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

    if (newIndex != oldIndex) {
      assetConfig.index = newIndex;
      emit AssetIndexUpdated(underlyingAsset, newIndex);
    }

    assetConfig.lastUpdateTimestamp = uint128(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)).div(1e18);
  }

  /**
   * @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) {
    if (
      emissionPerSecond == 0 ||
      totalBalance == 0 ||
      lastUpdateTimestamp == block.timestamp ||
      lastUpdateTimestamp >= DISTRIBUTION_END
    ) {
      return currentIndex;
    }

    uint256 currentTimestamp =
      block.timestamp > DISTRIBUTION_END ? DISTRIBUTION_END : block.timestamp;
    uint256 timeDelta = currentTimestamp.sub(lastUpdateTimestamp);
    return
      emissionPerSecond.mul(timeDelta).mul(1e18).div(totalBalance).add(
        currentIndex
      );
  }

  /**
   * @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) {
    return assets[asset].users[user];
  }
}
"
    },
    "contracts/interface/IERC20.sol": {
      "content": "// SPDX-License-Identifier: MIT
// File contracts/interfaces/IERC20.sol
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);
}"
    },
    "contracts/interface/IGovernancePowerDelegationToken.sol": {
      "content": "// SPDX-License-Identifier: MIT
// File @aave/aave-token/contracts/interfaces/IGovernancePowerDelegationToken.sol@v1.0.4
pragma solidity 0.7.5;

interface IGovernancePowerDelegationToken {
  enum DelegationType {VOTING_POWER, PROPOSITION_POWER}

  /**
   * @dev emitted when a user delegates to another
   * @param delegator the delegator
   * @param delegatee the delegatee
   * @param delegationType the type of delegation (VOTING_POWER, PROPOSITION_POWER)
   **/
  event DelegateChanged(
    address indexed delegator,
    address indexed delegatee,
    DelegationType delegationType
  );

  /**
   * @dev emitted when an action changes the delegated power of a user
   * @param user the user which delegated power has changed
   * @param amount the amount of delegated power for the user
   * @param delegationType the type of delegation (VOTING_POWER, PROPOSITION_POWER)
   **/
  event DelegatedPowerChanged(address indexed user, uint256 amount, DelegationType delegationType);

  /**
   * @dev delegates the specific power to a delegatee
   * @param delegatee the user which delegated power has changed
   * @param delegationType the type of delegation (VOTING_POWER, PROPOSITION_POWER)
   **/
  function delegateByType(address delegatee, DelegationType delegationType) external virtual;

  /**
   * @dev delegates all the powers to a specific user
   * @param delegatee the user to which the power will be delegated
   **/
  function delegate(address delegatee) external virtual;

  /**
   * @dev returns the delegatee of an user
   * @param delegator the address of the delegator
   **/
  function getDelegateeByType(address delegator, DelegationType delegationType)
    external
    view
    virtual
    returns (address);

  /**
   * @dev returns the current delegated power of a user. The current power is the
   * power delegated at the time of the last snapshot
   * @param user the user
   **/
  function getPowerCurrent(address user, DelegationType delegationType)
    external
    view
    virtual
    returns (uint256);

  /**
   * @dev returns the delegated power of a user at a certain block
   * @param user the user
   **/
  function getPowerAtBlock(
    address user,
    uint256 blockNumber,
    DelegationType delegationType
  ) external view virtual returns (uint256);

  /**
   * @dev returns the total supply at a certain block number
   **/
  function totalSupplyAt(uint256 blockNumber) external view virtual returns (uint256);
}
"
    },
    "contracts/interface/ITransferHook.sol": {
      "content": "// SPDX-License-Identifier: MIT
// File contracts/interfaces/ITransferHook.sol
pragma solidity 0.7.5;

interface ITransferHook {
  function onTransfer(
    address from,
    address to,
    uint256 amount
  ) external;
}"
    },
    "contracts/interface/IStakedAave.sol": {
      "content": "// SPDX-License-Identifier: MIT
// File contracts/interfaces/IStakedAave.sol
pragma solidity 0.7.5;

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

  function redeem(address to, uint256 amount) external;

  function cooldown() external;

  function claimRewards(address to, uint256 amount) external;
}"
    },
    "contracts/helper/Context.sol": {
      "content": "// SPDX-License-Identifier: MIT
// File contracts/lib/Context.sol
pragma solidity 0.7.5;
/**
 * @dev From https://github.com/OpenZeppelin/openzeppelin-contracts
 * Provides information about the current execution context, including the
 * sender of the transaction and its data. While these are generally available
 * via msg.sender and msg.data, they should not be accessed in such a direct
 * manner, since when dealing with GSN meta-transactions the account sending and
 * paying for execution may not be the actual sender (as far as an application
 * is concerned).
 *
 * This contract is only required for intermediate, library-like contracts.
 */
abstract contract Context {
  function _msgSender() internal view virtual returns (address payable) {
    return msg.sender;
  }

  function _msgData() internal view virtual returns (bytes calldata) {
    this; // silence state mutability warning without generating bytecode - see https://github.com/ethereum/solidity/issues/2691
    return msg.data[:msg.data.length - 20];
  }
}
"
    },
    "contracts/helper/GovernancePowerWithSnapshot.sol": {
      "content": "// SPDX-License-Identifier: MIT
// File contracts/lib/GovernancePowerWithSnapshot.sol

/**
 * @title ERC20WithSnapshot
 * @notice ERC20 including snapshots of balances on transfer-related actions
 * @author Aave
 **/

pragma solidity 0.7.5;
import "./GovernancePowerDelegationERC20.sol";
import "../interface/ITransferHook.sol";

abstract contract GovernancePowerWithSnapshot is GovernancePowerDelegationERC20 {
  using SafeMath for uint256;

  /**
   * @dev The following storage layout points to the prior StakedToken.sol implementation:
   * _snapshots => _votingSnapshots
   * _snapshotsCounts =>  _votingSnapshotsCounts
   * _aaveGovernance => _aaveGovernance
   */
  mapping(address => mapping(uint256 => Snapshot)) public _votingSnapshots;
  mapping(address => uint256) public _votingSnapshotsCounts;

  /// @dev reference to the Aave governance contract to call (if initialized) on _beforeTokenTransfer
  /// !!! IMPORTANT The Aave governance is considered a trustable contract, being its responsibility
  /// to control all potential reentrancies by calling back the this contract
  ITransferHook public _aaveGovernance;

  function _setAaveGovernance(ITransferHook aaveGovernance) internal virtual {
    _aaveGovernance = aaveGovernance;
  }
}"
    },
    "contracts/helper/GovernancePowerDelegationERC20.sol": {
      "content": "// SPDX-License-Identifier: MIT
// File @aave/aave-token/contracts/token/base/GovernancePowerDelegationERC20.sol@v1.0.4

/**
 * @notice implementation of the AAVE token contract
 * @author Aave
 */
pragma solidity 0.7.5;
import "./ERC20.sol";
import "../interface/IGovernancePowerDelegationToken.sol";

abstract contract GovernancePowerDelegationERC20 is ERC20, IGovernancePowerDelegationToken {
  using SafeMath for uint256;
  /// @notice The EIP-712 typehash for the delegation struct used by the contract
  bytes32 public constant DELEGATE_BY_TYPE_TYPEHASH =
    keccak256('DelegateByType(address delegatee,uint256 type,uint256 nonce,uint256 expiry)');

  bytes32 public constant DELEGATE_TYPEHASH =
    keccak256('Delegate(address delegatee,uint256 nonce,uint256 expiry)');

  /// @dev snapshot of a value on a specific block, used for votes
  struct Snapshot {
    uint128 blockNumber;
    uint128 value;
  }

  /**
   * @dev delegates one specific power to a delegatee
   * @param delegatee the user which delegated power has changed
   * @param delegationType the type of delegation (VOTING_POWER, PROPOSITION_POWER)
   **/
  function delegateByType(address delegatee, DelegationType delegationType) external override {
    _delegateByType(msg.sender, delegatee, delegationType);
  }

  /**
   * @dev delegates all the powers to a specific user
   * @param delegatee the user to which the power will be delegated
   **/
  function delegate(address delegatee) external override {
    _delegateByType(msg.sender, delegatee, DelegationType.VOTING_POWER);
    _delegateByType(msg.sender, delegatee, DelegationType.PROPOSITION_POWER);
  }

  /**
   * @dev returns the delegatee of an user
   * @param delegator the address of the delegator
   **/
  function getDelegateeByType(address delegator, DelegationType delegationType)
    external
    view
    override
    returns (address)
  {
    (, , mapping(address => address) storage delegates) = _getDelegationDataByType(delegationType);

    return _getDelegatee(delegator, delegates);
  }

  /**
   * @dev returns the current delegated power of a user. The current power is the
   * power delegated at the time of the last snapshot
   * @param user the user
   **/
  function getPowerCurrent(address user, DelegationType delegationType)
    external
    view
    override
    returns (uint256)
  {
    (
      mapping(address => mapping(uint256 => Snapshot)) storage snapshots,
      mapping(address => uint256) storage snapshotsCounts,

    ) = _getDelegationDataByType(delegationType);

    return _searchByBlockNumber(snapshots, snapshotsCounts, user, block.number);
  }

  /**
   * @dev returns the delegated power of a user at a certain block
   * @param user the user
   **/
  function getPowerAtBlock(
    address user,
    uint256 blockNumber,
    DelegationType delegationType
  ) external view override returns (uint256) {
    (
      mapping(address => mapping(uint256 => Snapshot)) storage snapshots,
      mapping(address => uint256) storage snapshotsCounts,

    ) = _getDelegationDataByType(delegationType);

    return _searchByBlockNumber(snapshots, snapshotsCounts, user, blockNumber);
  }

  /**
   * @dev returns the total supply at a certain block number
   * used by the voting strategy contracts to calculate the total votes needed for threshold/quorum
   * In this initial implementation with no AAVE minting, simply returns the current supply
   * A snapshots mapping will need to be added in case a mint function is added to the AAVE token in the future
   **/
  function totalSupplyAt(uint256 blockNumber) external view override returns (uint256) {
    return super.totalSupply();
  }

  /**
   * @dev delegates the specific power to a delegatee
   * @param delegatee the user which delegated power has changed
   * @param delegationType the type of delegation (VOTING_POWER, PROPOSITION_POWER)
   **/
  function _delegateByType(
    address delegator,
    address delegatee,
    DelegationType delegationType
  ) internal {
    require(delegatee != address(0), 'INVALID_DELEGATEE');

    (, , mapping(address => address) storage delegates) = _getDelegationDataByType(delegationType);

    uint256 delegatorBalance = balanceOf(delegator);

    address previousDelegatee = _getDelegatee(delegator, delegates);

    delegates[delegator] = delegatee;

    _moveDelegatesByType(previousDelegatee, delegatee, delegatorBalance, delegationType);
    emit DelegateChanged(delegator, delegatee, delegationType);
  }

  /**
   * @dev moves delegated power from one user to another
   * @param from the user from which delegated power is moved
   * @param to the user that will receive the delegated power
   * @param amount the amount of delegated power to be moved
   * @param delegationType the type of delegation (VOTING_POWER, PROPOSITION_POWER)
   **/
  function _moveDelegatesByType(
    address from,
    address to,
    uint256 amount,
    DelegationType delegationType
  ) internal {
    if (from == to) {
      return;
    }

    (
      mapping(address => mapping(uint256 => Snapshot)) storage snapshots,
      mapping(address => uint256) storage snapshotsCounts,

    ) = _getDelegationDataByType(delegationType);

    if (from != address(0)) {
      uint256 previous = 0;
      uint256 fromSnapshotsCount = snapshotsCounts[from];

      if (fromSnapshotsCount != 0) {
        previous = snapshots[from][fromSnapshotsCount - 1].value;
      } else {
        previous = balanceOf(from);
      }

      _writeSnapshot(
        snapshots,
        snapshotsCounts,
        from,
        uint128(previous),
        uint128(previous.sub(amount))
      );

      emit DelegatedPowerChanged(from, previous.sub(amount), delegationType);
    }
    if (to != address(0)) {
      uint256 previous = 0;
      uint256 toSnapshotsCount = snapshotsCounts[to];
      if (toSnapshotsCount != 0) {
        previous = snapshots[to][toSnapshotsCount - 1].value;
      } else {
        previous = balanceOf(to);
      }

      _writeSnapshot(
        snapshots,
        snapshotsCounts,
        to,
        uint128(previous),
        uint128(previous.add(amount))
      );

      emit DelegatedPowerChanged(to, previous.add(amount), delegationType);
    }
  }

  /**
   * @dev searches a snapshot by block number. Uses binary search.
   * @param snapshots the snapshots mapping
   * @param snapshotsCounts the number of snapshots
   * @param user the user for which the snapshot is being searched
   * @param blockNumber the block number being searched
   **/
  function _searchByBlockNumber(
    mapping(address => mapping(uint256 => Snapshot)) storage snapshots,
    mapping(address => uint256) storage snapshotsCounts,
    address user,
    uint256 blockNumber
  ) internal view returns (uint256) {
    require(blockNumber <= block.number, 'INVALID_BLOCK_NUMBER');

    uint256 snapshotsCount = snapshotsCounts[user];

    if (snapshotsCount == 0) {
      return balanceOf(user);
    }

    // First check most recent balance
    if (snapshots[user][snapshotsCount - 1].blockNumber <= blockNumber) {
      return snapshots[user][snapshotsCount - 1].value;
    }

    // Next check implicit zero balance
    if (snapshots[user][0].blockNumber > blockNumber) {
      return 0;
    }

    uint256 lower = 0;
    uint256 upper = snapshotsCount - 1;
    while (upper > lower) {
      uint256 center = upper - (upper - lower) / 2; // ceil, avoiding overflow
      Snapshot memory snapshot = snapshots[user][center];
      if (snapshot.blockNumber == blockNumber) {
        return snapshot.value;
      } else if (snapshot.blockNumber < blockNumber) {
        lower = center;
      } else {
        upper = center - 1;
      }
    }
    return snapshots[user][lower].value;
  }

  /**
   * @dev returns the delegation data (snapshot, snapshotsCount, list of delegates) by delegation type
   * NOTE: Ideal implementation would have mapped this in a struct by delegation type. Unfortunately,
   * the AAVE token and StakeToken already include a mapping for the snapshots, so we require contracts
   * who inherit from this to provide access to the delegation data by overriding this method.
   * @param delegationType the type of delegation
   **/
  function _getDelegationDataByType(DelegationType delegationType)
    internal
    view
    virtual
    returns (
      mapping(address => mapping(uint256 => Snapshot)) storage, //snapshots
      mapping(address => uint256) storage, //snapshots count
      mapping(address => address) storage //delegatees list
    );

  /**
   * @dev Writes a snapshot for an owner of tokens
   * @param owner The owner of the tokens
   * @param oldValue The value before the operation that is gonna be executed after the snapshot
   * @param newValue The value after the operation
   */
  function _writeSnapshot(
    mapping(address => mapping(uint256 => Snapshot)) storage snapshots,
    mapping(address => uint256) storage snapshotsCounts,
    address owner,
    uint128 oldValue,
    uint128 newValue
  ) internal {
    uint128 currentBlock = uint128(block.number);

    uint256 ownerSnapshotsCount = snapshotsCounts[owner];
    mapping(uint256 => Snapshot) storage snapshotsOwner = snapshots[owner];

    // Doing multiple operations in the same block
    if (
      ownerSnapshotsCount != 0 &&
      snapshotsOwner[ownerSnapshotsCount - 1].blockNumber == currentBlock
    ) {
      snapshotsOwner[ownerSnapshotsCount - 1].value = newValue;
    } else {
      snapshotsOwner[ownerSnapshotsCount] = Snapshot(currentBlock, newValue);
      snapshotsCounts[owner] = ownerSnapshotsCount + 1;
    }
  }

  /**
   * @dev returns the user delegatee. If a user never performed any delegation,
   * his delegated address will be 0x0. In that case we simply return the user itself
   * @param delegator the address of the user for which return the delegatee
   * @param delegates the array of delegates for a particular type of delegation
   **/
  function _getDelegatee(address delegator, mapping(address => address) storage delegates)
    internal
    view
    returns (address)
  {
    address previousDelegatee = delegates[delegator];

    if (previousDelegatee == address(0)) {
      return delegator;
    }

    return previousDelegatee;
  }
}"
    },
    "contracts/helper/VersionedInitializable.sol": {
      "content": "// SPDX-License-Identifier: MIT
// File contracts/utils/VersionedInitializable.sol
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;
}"
    },
    "contracts/helper/ERC2771Context.sol": {
      "content": "// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (metatx/ERC2771Context.sol)
pragma solidity 0.7.5;
import "./Context.sol";
import "./VersionedInitializable.sol";

/**
 * @dev Context variant with ERC2771 support.
 */
abstract contract ERC2771Context is Context, VersionedInitializable {
    address internal _trustedForwarder;

    function initializeTrustedForwarder( address trustedForwarder ) public initializer {
      _trustedForwarder = trustedForwarder;
    }

    function isTrustedForwarder(address forwarder) public view virtual returns (bool) {
        return forwarder == _trustedForwarder;
    }

    function _msgSender() internal view virtual override returns (address payable sender) {
        if (isTrustedForwarder(msg.sender)) {
            // The assembly code is more direct than the Solidity version using `abi.decode`.
            assembly {
                sender := shr(96, calldataload(sub(calldatasize(), 20)))
            }
        } else {
            return super._msgSender();
        }
    }

    function _msgData() internal view virtual override returns (bytes calldata) {
        if (isTrustedForwarder(msg.sender)) {
             return msg.data[:msg.data.length - 20];
        } else {
            return super._msgData();
        }
    }
}"
    },
    "contracts/lib/SafeERC20.sol": {
      "content": "// SPDX-License-Identifier: MIT
// File contracts/lib/SafeERC20.sol
pragma solidity 0.7.5;
import "./SafeMath.sol";
import "./Address.sol";
import "../interface/IERC20.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');
    }
  }
}"
    },
    "contracts/helper/Initializable.sol": {
      "content": "// SPDX-License-Identifier: MIT

pragma solidity 0.7.5;

/**
 * @dev This is a base contract to aid in writing upgradeable contracts, or any kind of contract that will be deployed
 * behind a proxy. Since a proxied contract can't have a constructor, it's common to move constructor logic to an
 * external initializer function, usually called `initialize`. It then becomes necessary to protect this initializer
 * function so it can only be called once. The {initializer} modifier provided by this contract will have this effect.
 *
 * TIP: To avoid leaving the proxy in an uninitialized state, the initializer function should be called as early as
 * possible by providing the encoded function call as the `_data` argument to {ERC1967Proxy-constructor}.
 *
 * CAUTION: When used with inheritance, manual care must be taken to not invoke a parent initializer twice, or to ensure
 * that all initializers are idempotent. This is not verified automatically as constructors are by Solidity.
 */
abstract contract Initializable {
    /**
     * @dev Indicates that the contract has been initialized.
     */
    bool private _initialized;

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

    /**
     * @dev Modifier to protect an initializer function from being invoked twice.
     */
    modifier reentrancy_initializer() {
        require(_initializing || !_initialized, "Initializable: contract is already initialized");

        bool isTopLevelCall = !_initializing;
        if (isTopLevelCall) {
            _initializing = true;
            _initialized = true;
        }

        _;

        if (isTopLevelCall) {
            _initializing = false;
        }
    }
}
"
    },
    "contracts/DistributionTypes.sol": {
      "content": "// SPDX-License-Identifier: MIT
pragma solidity 0.7.5;

// File contracts/lib/DistributionTypes.sol

library DistributionTypes {
  struct AssetConfigInput {
    uint128 emissionPerSecond;
    uint256 totalStaked;
    address underlyingAsset;
  }

  struct UserStakeInput {
    address underlyingAsset;
    uint256 stakedByUser;
    uint256 totalStaked;
  }
}
"
    },
    "contracts/lib/SafeMath.sol": {
      "content": "// SPDX-License-Identifier: MIT
pragma solidity 0.7.5;
// File contracts/lib/SafeMath.sol

/**
 * @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;
  }
}"
    },
    "contracts/interface/IAaveDistributionManager.sol": {
      "content": "// SPDX-License-Identifier: MIT
// File contracts/interfaces/IAaveDistributionManager.sol

pragma solidity 0.7.5;
pragma experimental ABIEncoderV2;
import "../DistributionTypes.sol";

interface IAaveDistributionManager {
  function configureAssets(DistributionTypes.AssetConfigInput[] calldata assetsConfigInput)
    external;
}"
    },
    "contracts/helper/ERC20.sol": {
      "content": "// SPDX-License-Identifier: MIT
// File @aave/aave-token/contracts/open-zeppelin/ERC20.sol@v1.0.4
pragma solidity 0.7.5;
import "./Context.sol";
import "../interface/IERC20.sol";
import "../lib/SafeMath.sol";
import "../lib/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 SafeMath for uint256;
  using Address for address;

  mapping(address => uint256) private _balances;

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

  uint256 private _totalSupply;

  string internal _name;
  string internal _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