Merge pull request #91 from aave/feat/81-add-ecosystem-reserve-contracts

Add contracts for reserve ecosystem updates

README.md

@@ -22,3 +22,23 @@ Aave is a decentralized non-custodial liquidity markets protocol where users can
 ## Connect with the community
 
 You can join at the [Discord](http://aave.com/discord) channel or at the [Governance Forum](https://governance.aave.com/) for asking questions about the protocol or talk about Aave with other peers.
+
+## Getting started
+
+Download the dependencies
+
+```
+npm i
+```
+
+Compile the contracts
+
+```
+npm run compile
+```
+
+## Running tests
+
+```
+npm test
+```

contracts/treasury/AaveEcosystemReserveController.sol

@@ -0,0 +1,71 @@
+// SPDX-License-Identifier: MIT
+pragma solidity ^0.8.10;
+
+import {Ownable} from '@aave/core-v3/contracts/dependencies/openzeppelin/contracts/Ownable.sol';
+import {IStreamable} from './interfaces/IStreamable.sol';
+import {IAdminControlledEcosystemReserve} from './interfaces/IAdminControlledEcosystemReserve.sol';
+import {IAaveEcosystemReserveController} from './interfaces/IAaveEcosystemReserveController.sol';
+import {IERC20} from '@aave/core-v3/contracts/dependencies/openzeppelin/contracts/IERC20.sol';
+
+contract AaveEcosystemReserveController is Ownable, IAaveEcosystemReserveController {
+  /**
+   * @notice Constructor.
+   * @param aaveGovShortTimelock The address of the Aave's governance executor, owning this contract
+   */
+  constructor(address aaveGovShortTimelock) {
+    transferOwnership(aaveGovShortTimelock);
+  }
+
+  /// @inheritdoc IAaveEcosystemReserveController
+  function approve(
+    address collector,
+    IERC20 token,
+    address recipient,
+    uint256 amount
+  ) external onlyOwner {
+    IAdminControlledEcosystemReserve(collector).approve(token, recipient, amount);
+  }
+
+  /// @inheritdoc IAaveEcosystemReserveController
+  function transfer(
+    address collector,
+    IERC20 token,
+    address recipient,
+    uint256 amount
+  ) external onlyOwner {
+    IAdminControlledEcosystemReserve(collector).transfer(token, recipient, amount);
+  }
+
+  /// @inheritdoc IAaveEcosystemReserveController
+  function createStream(
+    address collector,
+    address recipient,
+    uint256 deposit,
+    IERC20 tokenAddress,
+    uint256 startTime,
+    uint256 stopTime
+  ) external onlyOwner returns (uint256) {
+    return
+      IStreamable(collector).createStream(
+        recipient,
+        deposit,
+        address(tokenAddress),
+        startTime,
+        stopTime
+      );
+  }
+
+  /// @inheritdoc IAaveEcosystemReserveController
+  function withdrawFromStream(
+    address collector,
+    uint256 streamId,
+    uint256 funds
+  ) external onlyOwner returns (bool) {
+    return IStreamable(collector).withdrawFromStream(streamId, funds);
+  }
+
+  /// @inheritdoc IAaveEcosystemReserveController
+  function cancelStream(address collector, uint256 streamId) external onlyOwner returns (bool) {
+    return IStreamable(collector).cancelStream(streamId);
+  }
+}

contracts/treasury/AaveEcosystemReserveV2.sol

@@ -0,0 +1,303 @@
+// SPDX-License-Identifier: GPL-3.0
+pragma solidity ^0.8.10;
+
+import {IERC20} from '@aave/core-v3/contracts/dependencies/openzeppelin/contracts/IERC20.sol';
+import {IStreamable} from './interfaces/IStreamable.sol';
+import {AdminControlledEcosystemReserve} from './AdminControlledEcosystemReserve.sol';
+import {ReentrancyGuard} from './libs/ReentrancyGuard.sol';
+import {SafeERC20} from './libs/SafeERC20.sol';
+
+/**
+ * @title AaveEcosystemReserve v2
+ * @notice Stores ERC20 tokens of an ecosystem reserve, adding streaming capabilities.
+ * Modification of Sablier https://github.com/sablierhq/sablier/blob/develop/packages/protocol/contracts/Sablier.sol
+ * Original can be found also deployed on https://etherscan.io/address/0xCD18eAa163733Da39c232722cBC4E8940b1D8888
+ * Modifications:
+ * - Sablier "pulls" the funds from the creator of the stream at creation. In the Aave case, we already have the funds.
+ * - Anybody can create streams on Sablier. Here, only the funds admin (Aave governance via controller) can
+ * - Adapted codebase to Solidity 0.8.11, mainly removing SafeMath and CarefulMath to use native safe math
+ * - Same as with creation, on Sablier the `sender` and `recipient` can cancel a stream. Here, only fund admin and recipient
+ * @author BGD Labs
+ **/
+contract AaveEcosystemReserveV2 is AdminControlledEcosystemReserve, ReentrancyGuard, IStreamable {
+  using SafeERC20 for IERC20;
+
+  /*** Storage Properties ***/
+
+  /**
+   * @notice Counter for new stream ids.
+   */
+  uint256 private _nextStreamId;
+
+  /**
+   * @notice The stream objects identifiable by their unsigned integer ids.
+   */
+  mapping(uint256 => Stream) private _streams;
+
+  /*** Modifiers ***/
+
+  /**
+   * @dev Throws if the caller is not the funds admin of the recipient of the stream.
+   */
+  modifier onlyAdminOrRecipient(uint256 streamId) {
+    require(
+      msg.sender == _fundsAdmin || msg.sender == _streams[streamId].recipient,
+      'caller is not the funds admin or the recipient of the stream'
+    );
+    _;
+  }
+
+  /**
+   * @dev Throws if the provided id does not point to a valid stream.
+   */
+  modifier streamExists(uint256 streamId) {
+    require(_streams[streamId].isEntity, 'stream does not exist');
+    _;
+  }
+
+  /*** Contract Logic Starts Here */
+
+  function initialize(address fundsAdmin) external initializer {
+    _nextStreamId = 100000;
+    _setFundsAdmin(fundsAdmin);
+  }
+
+  /*** View Functions ***/
+
+  /**
+   * @notice Returns the next available stream id
+   * @notice Returns the stream id.
+   */
+  function getNextStreamId() external view returns (uint256) {
+    return _nextStreamId;
+  }
+
+  /**
+   * @notice Returns the stream with all its properties.
+   * @dev Throws if the id does not point to a valid stream.
+   * @param streamId The id of the stream to query.
+   * @notice Returns the stream object.
+   */
+  function getStream(uint256 streamId)
+    external
+    view
+    streamExists(streamId)
+    returns (
+      address sender,
+      address recipient,
+      uint256 deposit,
+      address tokenAddress,
+      uint256 startTime,
+      uint256 stopTime,
+      uint256 remainingBalance,
+      uint256 ratePerSecond
+    )
+  {
+    sender = _streams[streamId].sender;
+    recipient = _streams[streamId].recipient;
+    deposit = _streams[streamId].deposit;
+    tokenAddress = _streams[streamId].tokenAddress;
+    startTime = _streams[streamId].startTime;
+    stopTime = _streams[streamId].stopTime;
+    remainingBalance = _streams[streamId].remainingBalance;
+    ratePerSecond = _streams[streamId].ratePerSecond;
+  }
+
+  /**
+   * @notice Returns either the delta in seconds between `block.timestamp` and `startTime` or
+   *  between `stopTime` and `startTime, whichever is smaller. If `block.timestamp` is before
+   *  `startTime`, it returns 0.
+   * @dev Throws if the id does not point to a valid stream.
+   * @param streamId The id of the stream for which to query the delta.
+   * @notice Returns the time delta in seconds.
+   */
+  function deltaOf(uint256 streamId) public view streamExists(streamId) returns (uint256 delta) {
+    Stream memory stream = _streams[streamId];
+    if (block.timestamp <= stream.startTime) return 0;
+    if (block.timestamp < stream.stopTime) return block.timestamp - stream.startTime;
+    return stream.stopTime - stream.startTime;
+  }
+
+  struct BalanceOfLocalVars {
+    uint256 recipientBalance;
+    uint256 withdrawalAmount;
+    uint256 senderBalance;
+  }
+
+  /**
+   * @notice Returns the available funds for the given stream id and address.
+   * @dev Throws if the id does not point to a valid stream.
+   * @param streamId The id of the stream for which to query the balance.
+   * @param who The address for which to query the balance.
+   * @notice Returns the total funds allocated to `who` as uint256.
+   */
+  function balanceOf(uint256 streamId, address who)
+    public
+    view
+    streamExists(streamId)
+    returns (uint256 balance)
+  {
+    Stream memory stream = _streams[streamId];
+    BalanceOfLocalVars memory vars;
+
+    uint256 delta = deltaOf(streamId);
+    vars.recipientBalance = delta * stream.ratePerSecond;
+
+    /*
+     * If the stream `balance` does not equal `deposit`, it means there have been withdrawals.
+     * We have to subtract the total amount withdrawn from the amount of money that has been
+     * streamed until now.
+     */
+    if (stream.deposit > stream.remainingBalance) {
+      vars.withdrawalAmount = stream.deposit - stream.remainingBalance;
+      vars.recipientBalance = vars.recipientBalance - vars.withdrawalAmount;
+    }
+
+    if (who == stream.recipient) return vars.recipientBalance;
+    if (who == stream.sender) {
+      vars.senderBalance = stream.remainingBalance - vars.recipientBalance;
+      return vars.senderBalance;
+    }
+    return 0;
+  }
+
+  /*** Public Effects & Interactions Functions ***/
+
+  struct CreateStreamLocalVars {
+    uint256 duration;
+    uint256 ratePerSecond;
+  }
+
+  /**
+   * @notice Creates a new stream funded by this contracts itself and paid towards `recipient`.
+   * @dev Throws if the recipient is the zero address, the contract itself or the caller.
+   *  Throws if the deposit is 0.
+   *  Throws if the start time is before `block.timestamp`.
+   *  Throws if the stop time is before the start time.
+   *  Throws if the duration calculation has a math error.
+   *  Throws if the deposit is smaller than the duration.
+   *  Throws if the deposit is not a multiple of the duration.
+   *  Throws if the rate calculation has a math error.
+   *  Throws if the next stream id calculation has a math error.
+   *  Throws if the contract is not allowed to transfer enough tokens.
+   *  Throws if there is a token transfer failure.
+   * @param recipient The address towards which the money is streamed.
+   * @param deposit The amount of money to be streamed.
+   * @param tokenAddress The ERC20 token to use as streaming currency.
+   * @param startTime The unix timestamp for when the stream starts.
+   * @param stopTime The unix timestamp for when the stream stops.
+   * @notice Returns the uint256 id of the newly created stream.
+   */
+  function createStream(
+    address recipient,
+    uint256 deposit,
+    address tokenAddress,
+    uint256 startTime,
+    uint256 stopTime
+  ) external onlyFundsAdmin returns (uint256) {
+    require(recipient != address(0), 'stream to the zero address');
+    require(recipient != address(this), 'stream to the contract itself');
+    require(recipient != msg.sender, 'stream to the caller');
+    require(deposit > 0, 'deposit is zero');
+    require(startTime >= block.timestamp, 'start time before block.timestamp');
+    require(stopTime > startTime, 'stop time before the start time');
+
+    CreateStreamLocalVars memory vars;
+    vars.duration = stopTime - startTime;
+
+    /* Without this, the rate per second would be zero. */
+    require(deposit >= vars.duration, 'deposit smaller than time delta');
+
+    /* This condition avoids dealing with remainders */
+    require(deposit % vars.duration == 0, 'deposit not multiple of time delta');
+
+    vars.ratePerSecond = deposit / vars.duration;
+
+    /* Create and store the stream object. */
+    uint256 streamId = _nextStreamId;
+    _streams[streamId] = Stream({
+      remainingBalance: deposit,
+      deposit: deposit,
+      isEntity: true,
+      ratePerSecond: vars.ratePerSecond,
+      recipient: recipient,
+      sender: address(this),
+      startTime: startTime,
+      stopTime: stopTime,
+      tokenAddress: tokenAddress
+    });
+
+    /* Increment the next stream id. */
+    _nextStreamId++;
+
+    emit CreateStream(
+      streamId,
+      address(this),
+      recipient,
+      deposit,
+      tokenAddress,
+      startTime,
+      stopTime
+    );
+    return streamId;
+  }
+
+  /**
+   * @notice Withdraws from the contract to the recipient's account.
+   * @dev Throws if the id does not point to a valid stream.
+   *  Throws if the caller is not the funds admin or the recipient of the stream.
+   *  Throws if the amount exceeds the available balance.
+   *  Throws if there is a token transfer failure.
+   * @param streamId The id of the stream to withdraw tokens from.
+   * @param amount The amount of tokens to withdraw.
+   */
+  function withdrawFromStream(uint256 streamId, uint256 amount)
+    external
+    nonReentrant
+    streamExists(streamId)
+    onlyAdminOrRecipient(streamId)
+    returns (bool)
+  {
+    require(amount > 0, 'amount is zero');
+    Stream memory stream = _streams[streamId];
+
+    uint256 balance = balanceOf(streamId, stream.recipient);
+    require(balance >= amount, 'amount exceeds the available balance');
+
+    _streams[streamId].remainingBalance = stream.remainingBalance - amount;
+
+    if (_streams[streamId].remainingBalance == 0) delete _streams[streamId];
+
+    IERC20(stream.tokenAddress).safeTransfer(stream.recipient, amount);
+    emit WithdrawFromStream(streamId, stream.recipient, amount);
+    return true;
+  }
+
+  /**
+   * @notice Cancels the stream and transfers the tokens back on a pro rata basis.
+   * @dev Throws if the id does not point to a valid stream.
+   *  Throws if the caller is not the funds admin or the recipient of the stream.
+   *  Throws if there is a token transfer failure.
+   * @param streamId The id of the stream to cancel.
+   * @notice Returns bool true=success, otherwise false.
+   */
+  function cancelStream(uint256 streamId)
+    external
+    nonReentrant
+    streamExists(streamId)
+    onlyAdminOrRecipient(streamId)
+    returns (bool)
+  {
+    Stream memory stream = _streams[streamId];
+    uint256 senderBalance = balanceOf(streamId, stream.sender);
+    uint256 recipientBalance = balanceOf(streamId, stream.recipient);
+
+    delete _streams[streamId];
+
+    IERC20 token = IERC20(stream.tokenAddress);
+    if (recipientBalance > 0) token.safeTransfer(stream.recipient, recipientBalance);
+
+    emit CancelStream(streamId, stream.sender, stream.recipient, senderBalance, recipientBalance);
+    return true;
+  }
+}