aave-protocol-v2/contracts/misc/UiPoolDataProvider.sol

// SPDX-License-Identifier: agpl-3.0
pragma solidity 0.6.12;
pragma experimental ABIEncoderV2;

import {IERC20Detailed} from '../dependencies/openzeppelin/contracts/IERC20Detailed.sol';
import {ILendingPoolAddressesProvider} from '../interfaces/ILendingPoolAddressesProvider.sol';
import {IUiPoolDataProvider} from './interfaces/IUiPoolDataProvider.sol';
import {ILendingPool} from '../interfaces/ILendingPool.sol';
import {IAaveOracle} from './interfaces/IAaveOracle.sol';
import {IAToken} from '../interfaces/IAToken.sol';
import {IVariableDebtToken} from '../interfaces/IVariableDebtToken.sol';
import {IStableDebtToken} from '../interfaces/IStableDebtToken.sol';
import {WadRayMath} from '../protocol/libraries/math/WadRayMath.sol';
import {ReserveConfiguration} from '../protocol/libraries/configuration/ReserveConfiguration.sol';
import {UserConfiguration} from '../protocol/libraries/configuration/UserConfiguration.sol';
import {DataTypes} from '../protocol/libraries/types/DataTypes.sol';
import {
  DefaultReserveInterestRateStrategy
} from '../protocol/lendingpool/DefaultReserveInterestRateStrategy.sol';

contract UiPoolDataProvider is IUiPoolDataProvider {
  using WadRayMath for uint256;
  using ReserveConfiguration for DataTypes.ReserveConfigurationMap;
  using UserConfiguration for DataTypes.UserConfigurationMap;

  address public constant MOCK_USD_ADDRESS = 0x10F7Fc1F91Ba351f9C629c5947AD69bD03C05b96;
  uint256 public constant USD_PRICE = 100000000;
  uint256 public constant ETH_CURRENCY_DECIMALS = 18;

  constructor() public {
  }

  function getInterestRateStrategySlopes(DefaultReserveInterestRateStrategy interestRateStrategy)
    internal
    view
    returns (
      uint256,
      uint256,
      uint256,
      uint256
    )
  {
    return (
      interestRateStrategy.variableRateSlope1(),
      interestRateStrategy.variableRateSlope2(),
      interestRateStrategy.stableRateSlope1(),
      interestRateStrategy.stableRateSlope2()
    );
  }

  function getReservesList(ILendingPoolAddressesProvider provider)
    public
    view
    override
    returns (address[] memory)
  {
    ILendingPool lendingPool = ILendingPool(provider.getLendingPool());
    return lendingPool.getReservesList();
  }

  function getReservesData(ILendingPoolAddressesProvider provider)
    public
    view
    override
    returns (
      AggregatedReserveData[] memory,
      BaseCurrencyInfo memory
    )
  {
    IAaveOracle oracle = IAaveOracle(provider.getPriceOracle());
    ILendingPool lendingPool = ILendingPool(provider.getLendingPool());
    address[] memory reserves = lendingPool.getReservesList();
    AggregatedReserveData[] memory reservesData = new AggregatedReserveData[](reserves.length);

    for (uint256 i = 0; i < reserves.length; i++) {
      AggregatedReserveData memory reserveData = reservesData[i];
      reserveData.underlyingAsset = reserves[i];

      // reserve current state
      DataTypes.ReserveData memory baseData =
        lendingPool.getReserveData(reserveData.underlyingAsset);
      reserveData.liquidityIndex = baseData.liquidityIndex;
      reserveData.variableBorrowIndex = baseData.variableBorrowIndex;
      reserveData.liquidityRate = baseData.currentLiquidityRate;
      reserveData.variableBorrowRate = baseData.currentVariableBorrowRate;
      reserveData.stableBorrowRate = baseData.currentStableBorrowRate;
      reserveData.lastUpdateTimestamp = baseData.lastUpdateTimestamp;
      reserveData.aTokenAddress = baseData.aTokenAddress;
      reserveData.stableDebtTokenAddress = baseData.stableDebtTokenAddress;
      reserveData.variableDebtTokenAddress = baseData.variableDebtTokenAddress;
      reserveData.interestRateStrategyAddress = baseData.interestRateStrategyAddress;
      reserveData.priceInMarketReferenceCurrency = oracle.getAssetPrice(reserveData.underlyingAsset);

      reserveData.availableLiquidity = IERC20Detailed(reserveData.underlyingAsset).balanceOf(
        reserveData.aTokenAddress
      );
      (
        reserveData.totalPrincipalStableDebt,
        ,
        reserveData.averageStableRate,
        reserveData.stableDebtLastUpdateTimestamp
      ) = IStableDebtToken(reserveData.stableDebtTokenAddress).getSupplyData();
      reserveData.totalScaledVariableDebt = IVariableDebtToken(reserveData.variableDebtTokenAddress)
        .scaledTotalSupply();

      // we're getting this info from the aToken, because some of assets can be not compliant with ETC20Detailed
      reserveData.symbol = IERC20Detailed(reserveData.underlyingAsset).symbol();
      reserveData.name = '';

      (
        reserveData.baseLTVasCollateral,
        reserveData.reserveLiquidationThreshold,
        reserveData.reserveLiquidationBonus,
        reserveData.decimals,
        reserveData.reserveFactor
      ) = baseData.configuration.getParamsMemory();
      (
        reserveData.isActive,
        reserveData.isFrozen,
        reserveData.borrowingEnabled,
        reserveData.stableBorrowRateEnabled
      ) = baseData.configuration.getFlagsMemory();
      reserveData.usageAsCollateralEnabled = reserveData.baseLTVasCollateral != 0;
      (
        reserveData.variableRateSlope1,
        reserveData.variableRateSlope2,
        reserveData.stableRateSlope1,
        reserveData.stableRateSlope2
      ) = getInterestRateStrategySlopes(
        DefaultReserveInterestRateStrategy(reserveData.interestRateStrategyAddress)
      );
    }

    BaseCurrencyInfo memory baseCurrencyInfo;
    try oracle.BASE_CURRENCY_UNIT() returns (uint256 baseCurrencyUnit) {        
      baseCurrencyInfo.baseCurrencyDecimals = baseCurrencyUnit;
      if (address(0) == oracle.BASE_CURRENCY()) {
        baseCurrencyInfo.baseCurrencyPriceInUsd = USD_PRICE;
      } else {
        baseCurrencyInfo.baseCurrencyPriceInUsd = oracle.getAssetPrice(MOCK_USD_ADDRESS);
      }
    } catch (bytes memory /*lowLevelData*/) {  
      baseCurrencyInfo.baseCurrencyDecimals = ETH_CURRENCY_DECIMALS;
      baseCurrencyInfo.baseCurrencyPriceInUsd = oracle.getAssetPrice(MOCK_USD_ADDRESS);
    }

    return (reservesData, baseCurrencyInfo);
  }

  function getUserReservesData(ILendingPoolAddressesProvider provider, address user)
    external
    view
    override
    returns (UserReserveData[] memory)
  {
    ILendingPool lendingPool = ILendingPool(provider.getLendingPool());
    address[] memory reserves = lendingPool.getReservesList();
    DataTypes.UserConfigurationMap memory userConfig = lendingPool.getUserConfiguration(user);

    UserReserveData[] memory userReservesData =
      new UserReserveData[](user != address(0) ? reserves.length : 0);

    for (uint256 i = 0; i < reserves.length; i++) {
      DataTypes.ReserveData memory baseData = lendingPool.getReserveData(reserves[i]);

      // user reserve data
      userReservesData[i].underlyingAsset = reserves[i];
      userReservesData[i].scaledATokenBalance = IAToken(baseData.aTokenAddress).scaledBalanceOf(
        user
      );
      userReservesData[i].usageAsCollateralEnabledOnUser = userConfig.isUsingAsCollateral(i);

      if (userConfig.isBorrowing(i)) {
        userReservesData[i].scaledVariableDebt = IVariableDebtToken(
          baseData
            .variableDebtTokenAddress
        )
          .scaledBalanceOf(user);
        userReservesData[i].principalStableDebt = IStableDebtToken(baseData.stableDebtTokenAddress)
          .principalBalanceOf(user);
        if (userReservesData[i].principalStableDebt != 0) {
          userReservesData[i].stableBorrowRate = IStableDebtToken(baseData.stableDebtTokenAddress)
            .getUserStableRate(user);
          userReservesData[i].stableBorrowLastUpdateTimestamp = IStableDebtToken(
            baseData
              .stableDebtTokenAddress
          )
            .getUserLastUpdated(user);
        }
      }
    }

    return (userReservesData);
  }
}