Merge pull request #14 from Instadapp/aave-v2-amm

Add Aave v2 AMM Market

contracts/connectors/aave/v2-amm/events.sol

@@ -0,0 +1,10 @@
+pragma solidity ^0.7.0;
+
+contract Events {
+    event LogDeposit(address indexed token, uint256 tokenAmt, uint256 getId, uint256 setId);
+    event LogWithdraw(address indexed token, uint256 tokenAmt, uint256 getId, uint256 setId);
+    event LogBorrow(address indexed token, uint256 tokenAmt, uint256 indexed rateMode, uint256 getId, uint256 setId);
+    event LogPayback(address indexed token, uint256 tokenAmt, uint256 indexed rateMode, uint256 getId, uint256 setId);
+    event LogEnableCollateral(address[] tokens);
+    event LogSwapRateMode(address indexed token, uint256 rateMode);
+}

contracts/connectors/aave/v2-amm/helpers.sol

@@ -0,0 +1,48 @@
+pragma solidity ^0.7.0;
+
+import { DSMath } from "../../../common/math.sol";
+import { Basic } from "../../../common/basic.sol";
+import { AaveLendingPoolProviderInterface, AaveDataProviderInterface } from "./interface.sol";
+
+abstract contract Helpers is DSMath, Basic {
+    /**
+     * @dev Aave Lending Pool Provider
+    */
+    AaveLendingPoolProviderInterface constant internal aaveProvider = AaveLendingPoolProviderInterface(0xAcc030EF66f9dFEAE9CbB0cd1B25654b82cFA8d5);
+
+    /**
+     * @dev Aave Protocol Data Provider
+    */
+    AaveDataProviderInterface constant internal aaveData = AaveDataProviderInterface(0xc443AD9DDE3cecfB9dfC5736578f447aFE3590ba);
+
+    /**
+     * @dev Aave Referral Code
+    */
+    uint16 constant internal referralCode = 3228;
+
+    /**
+     * @dev Checks if collateral is enabled for an asset
+     * @param token token address of the asset.(For ETH: 0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE)
+    */
+    function getIsColl(address token) internal view returns (bool isCol) {
+        (, , , , , , , , isCol) = aaveData.getUserReserveData(token, address(this));
+    }
+
+    /**
+     * @dev Get total debt balance & fee for an asset
+     * @param token token address of the debt.(For ETH: 0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE)
+     * @param rateMode Borrow rate mode (Stable = 1, Variable = 2)
+    */
+    function getPaybackBalance(address token, uint rateMode) internal view returns (uint) {
+        (, uint stableDebt, uint variableDebt, , , , , , ) = aaveData.getUserReserveData(token, address(this));
+        return rateMode == 1 ? stableDebt : variableDebt;
+    }
+
+    /**
+     * @dev Get total collateral balance for an asset
+     * @param token token address of the collateral.(For ETH: 0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE)
+    */
+    function getCollateralBalance(address token) internal view returns (uint bal) {
+        (bal, , , , , , , ,) = aaveData.getUserReserveData(token, address(this));
+    }
+}

contracts/connectors/aave/v2-amm/interface.sol

@@ -0,0 +1,47 @@
+pragma solidity ^0.7.0;
+
+interface AaveInterface {
+    function deposit(address _asset, uint256 _amount, address _onBehalfOf, uint16 _referralCode) external;
+    function withdraw(address _asset, uint256 _amount, address _to) external;
+    function borrow(
+        address _asset,
+        uint256 _amount,
+        uint256 _interestRateMode,
+        uint16 _referralCode,
+        address _onBehalfOf
+    ) external;
+    function repay(address _asset, uint256 _amount, uint256 _rateMode, address _onBehalfOf) external;
+    function setUserUseReserveAsCollateral(address _asset, bool _useAsCollateral) external;
+    function swapBorrowRateMode(address _asset, uint256 _rateMode) external;
+}
+
+interface AaveLendingPoolProviderInterface {
+    function getLendingPool() external view returns (address);
+}
+
+interface AaveDataProviderInterface {
+    function getReserveTokensAddresses(address _asset) external view returns (
+        address aTokenAddress,
+        address stableDebtTokenAddress,
+        address variableDebtTokenAddress
+    );
+    function getUserReserveData(address _asset, address _user) external view returns (
+        uint256 currentATokenBalance,
+        uint256 currentStableDebt,
+        uint256 currentVariableDebt,
+        uint256 principalStableDebt,
+        uint256 scaledVariableDebt,
+        uint256 stableBorrowRate,
+        uint256 liquidityRate,
+        uint40 stableRateLastUpdated,
+        bool usageAsCollateralEnabled
+    );
+}
+
+interface AaveAddressProviderRegistryInterface {
+    function getAddressesProvidersList() external view returns (address[] memory);
+}
+
+interface ATokenInterface {
+    function balanceOf(address _user) external view returns(uint256);
+}

contracts/connectors/aave/v2-amm/main.sol

@@ -0,0 +1,205 @@
+pragma solidity ^0.7.0;
+
+import { TokenInterface } from "../../../common/interfaces.sol";
+import { Stores } from "../../../common/stores.sol";
+import { Helpers } from "./helpers.sol";
+import { Events } from "./events.sol";
+import { AaveInterface } from "./interface.sol";
+
+abstract contract AaveResolver is Events, Helpers {
+    /**
+     * @dev Deposit ETH/ERC20_Token.
+     * @param token token address to deposit.(For ETH: 0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE)
+     * @param amt token amount to deposit.
+     * @param getId Get token amount at this ID from `InstaMemory` Contract.
+     * @param setId Set token amount at this ID in `InstaMemory` Contract.
+    */
+    function deposit(
+        address token,
+        uint256 amt,
+        uint256 getId,
+        uint256 setId
+    ) external payable returns (string memory _eventName, bytes memory _eventParam) {
+        uint _amt = getUint(getId, amt);
+
+        AaveInterface aave = AaveInterface(aaveProvider.getLendingPool());
+
+        bool isEth = token == ethAddr;
+        address _token = isEth ? wethAddr : token;
+
+        TokenInterface tokenContract = TokenInterface(_token);
+
+        if (isEth) {
+            _amt = _amt == uint(-1) ? address(this).balance : _amt;
+            convertEthToWeth(isEth, tokenContract, _amt);
+        } else {
+            _amt = _amt == uint(-1) ? tokenContract.balanceOf(address(this)) : _amt;
+        }
+
+        tokenContract.approve(address(aave), _amt);
+
+        aave.deposit(_token, _amt, address(this), referralCode);
+
+        if (!getIsColl(_token)) {
+            aave.setUserUseReserveAsCollateral(_token, true);
+        }
+
+        setUint(setId, _amt);
+
+        _eventName = "LogDeposit(address,uint256,uint256,uint256)";
+        _eventParam = abi.encode(token, _amt, getId, setId);
+    }
+
+    /**
+     * @dev Withdraw ETH/ERC20_Token.
+     * @param token token address to withdraw.(For ETH: 0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE)
+     * @param amt token amount to withdraw.
+     * @param getId Get token amount at this ID from `InstaMemory` Contract.
+     * @param setId Set token amount at this ID in `InstaMemory` Contract.
+    */
+    function withdraw(
+        address token,
+        uint256 amt,
+        uint256 getId,
+        uint256 setId
+    ) external payable returns (string memory _eventName, bytes memory _eventParam) {
+        uint _amt = getUint(getId, amt);
+
+        AaveInterface aave = AaveInterface(aaveProvider.getLendingPool());
+        bool isEth = token == ethAddr;
+        address _token = isEth ? wethAddr : token;
+
+        TokenInterface tokenContract = TokenInterface(_token);
+
+        uint initialBal = tokenContract.balanceOf(address(this));
+        aave.withdraw(_token, _amt, address(this));
+        uint finalBal = tokenContract.balanceOf(address(this));
+
+        _amt = sub(finalBal, initialBal);
+
+        convertWethToEth(isEth, tokenContract, _amt);
+        
+        setUint(setId, _amt);
+
+        _eventName = "LogWithdraw(address,uint256,uint256,uint256)";
+        _eventParam = abi.encode(token, _amt, getId, setId);
+    }
+
+    /**
+     * @dev Borrow ETH/ERC20_Token.
+     * @param token token address to borrow.(For ETH: 0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE)
+     * @param amt token amount to borrow.
+     * @param rateMode type of borrow debt.(For Stable: 1, Variable: 2)
+     * @param getId Get token amount at this ID from `InstaMemory` Contract.
+     * @param setId Set token amount at this ID in `InstaMemory` Contract.
+    */
+    function borrow(
+        address token,
+        uint256 amt,
+        uint256 rateMode,
+        uint256 getId,
+        uint256 setId
+    ) external payable returns (string memory _eventName, bytes memory _eventParam) {
+        uint _amt = getUint(getId, amt);
+
+        AaveInterface aave = AaveInterface(aaveProvider.getLendingPool());
+
+        bool isEth = token == ethAddr;
+        address _token = isEth ? wethAddr : token;
+
+        aave.borrow(_token, _amt, rateMode, referralCode, address(this));
+        convertWethToEth(isEth, TokenInterface(_token), _amt);
+
+        setUint(setId, _amt);
+
+        _eventName = "LogBorrow(address,uint256,uint256,uint256,uint256)";
+        _eventParam = abi.encode(token, _amt, rateMode, getId, setId);
+    }
+
+    /**
+     * @dev Payback borrowed ETH/ERC20_Token.
+     * @param token token address to payback.(For ETH: 0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE)
+     * @param amt token amount to payback.
+     * @param rateMode type of borrow debt.(For Stable: 1, Variable: 2)
+     * @param getId Get token amount at this ID from `InstaMemory` Contract.
+     * @param setId Set token amount at this ID in `InstaMemory` Contract.
+    */
+    function payback(
+        address token,
+        uint256 amt,
+        uint256 rateMode,
+        uint256 getId,
+        uint256 setId
+    ) external payable returns (string memory _eventName, bytes memory _eventParam) {
+        uint _amt = getUint(getId, amt);
+
+        AaveInterface aave = AaveInterface(aaveProvider.getLendingPool());
+
+        bool isEth = token == ethAddr;
+        address _token = isEth ? wethAddr : token;
+
+        TokenInterface tokenContract = TokenInterface(_token);
+
+        _amt = _amt == uint(-1) ? getPaybackBalance(_token, rateMode) : _amt;
+
+        if (isEth) convertEthToWeth(isEth, tokenContract, _amt);
+
+        tokenContract.approve(address(aave), _amt);
+
+        aave.repay(_token, _amt, rateMode, address(this));
+
+        setUint(setId, _amt);
+
+        _eventName = "LogPayback(address,uint256,uint256,uint256,uint256)";
+        _eventParam = abi.encode(token, _amt, rateMode, getId, setId);
+    }
+
+    /**
+     * @dev Enable collateral
+     * @param tokens Array of tokens to enable collateral
+    */
+    function enableCollateral(
+        address[] calldata tokens
+    ) external payable returns (string memory _eventName, bytes memory _eventParam) {
+        uint _length = tokens.length;
+        require(_length > 0, "0-tokens-not-allowed");
+
+        AaveInterface aave = AaveInterface(aaveProvider.getLendingPool());
+
+        for (uint i = 0; i < _length; i++) {
+            address token = tokens[i];
+            if (getCollateralBalance(token) > 0 && !getIsColl(token)) {
+                aave.setUserUseReserveAsCollateral(token, true);
+            }
+        }
+
+        _eventName = "LogEnableCollateral(address[])";
+        _eventParam = abi.encode(tokens);
+    }
+
+    /**
+     * @dev Swap borrow rate mode
+     * @notice Swaps user borrow rate mode between variable and stable
+     * @param token The address of the token to swap borrow rate.(For ETH: 0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE)
+     * @param rateMode Desired borrow rate mode. (Stable = 1, Variable = 2)
+    */
+    function swapBorrowRateMode(
+        address token,
+        uint rateMode
+    ) external payable returns (string memory _eventName, bytes memory _eventParam) {
+        AaveInterface aave = AaveInterface(aaveProvider.getLendingPool());
+
+        uint currentRateMode = rateMode == 1 ? 2 : 1;
+
+        if (getPaybackBalance(token, currentRateMode) > 0) {
+            aave.swapBorrowRateMode(token, rateMode);
+        }
+
+        _eventName = "LogSwapRateMode(address,uint256)";
+        _eventParam = abi.encode(token, rateMode);
+    }
+}
+
+contract ConnectV2AaveV2AMM is AaveResolver {
+    string constant public name = "AaveV2-AMM-v1";
+}