Merge pull request #45 from ionicprotocol/feat/redstone-oracle

Redstone oracle

contracts/external/redstone/IRedstoneOracle.sol

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+// SPDX-License-Identifier: MIT
+pragma solidity >=0.8.0;
+
+interface IRedstoneOracle {
+  function priceOf(address asset) external view returns (uint256);
+
+  function priceOfETH() external view returns (uint256);
+
+  function getDataFeedIdForAsset(address asset) external view returns (bytes32);
+
+  function getDataFeedIds() external view returns (bytes32[] memory dataFeedIds);
+}

contracts/oracles/default/RedstoneAdapterPriceOracle.sol

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+// SPDX-License-Identifier: UNLICENSED
+pragma solidity >=0.8.0;
+
+import "openzeppelin-contracts-upgradeable/contracts/token/ERC20/ERC20Upgradeable.sol";
+
+import "../../external/redstone/IRedstoneOracle.sol";
+import "../BasePriceOracle.sol";
+
+/**
+ * @title RedstoneAdapterPriceOracle
+ * @notice Returns prices from Redstone.
+ * @dev Implements `BasePriceOracle`.
+ * @author Veliko Minkov <[email protected]> (https://github.com/vminkov)
+ */
+contract RedstoneAdapterPriceOracle is BasePriceOracle {
+  /**
+   * @notice The Redstone oracle contract
+   */
+  IRedstoneOracle public REDSTONE_ORACLE;
+
+  /**
+   * @dev Constructor to set admin, wtoken address and native token USD price feed address
+   * @param redstoneOracle The Redstone oracle contract address
+   */
+  constructor(address redstoneOracle) {
+    REDSTONE_ORACLE = IRedstoneOracle(redstoneOracle);
+  }
+
+  /**
+   * @notice Internal function returning the price in of `underlying`.
+   * @dev will return a price denominated in the native token
+   */
+  function _price(address underlying) internal view returns (uint256) {
+    uint256 priceInUsd = REDSTONE_ORACLE.priceOf(underlying);
+    uint256 priceOfNativeInUsd = REDSTONE_ORACLE.priceOfETH();
+    return (priceInUsd * 1e18) / priceOfNativeInUsd;
+  }
+
+  /**
+   * @notice Returns the price in of `underlying` either in the
+   * native token (implements `BasePriceOracle`).
+   */
+  function price(address underlying) external view override returns (uint256) {
+    return _price(underlying);
+  }
+
+  /**
+   * @notice Returns the price in WNATIVE of the token underlying `cToken`.
+   * @dev Implements the `BasePriceOracle` interface for Ionic pools (and Compound v2).
+   * @return Price in WNATIVE of the token underlying `cToken`, scaled by `10 ** (36 - underlyingDecimals)`.
+   */
+  function getUnderlyingPrice(ICErc20 cToken) external view override returns (uint256) {
+    // Get underlying token address
+    address underlying = cToken.underlying();
+
+    uint256 oraclePrice = _price(underlying);
+
+    uint256 underlyingDecimals = uint256(ERC20Upgradeable(underlying).decimals());
+    return
+      underlyingDecimals <= 18
+        ? uint256(oraclePrice) * (10**(18 - underlyingDecimals))
+        : uint256(oraclePrice) / (10**(underlyingDecimals - 18));
+  }
+}

contracts/test/oracles/RedstoneAdapterOracleTest.t.sol

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+// SPDX-License-Identifier: UNLICENSED
+pragma solidity >=0.8.0;
+
+import { TransparentUpgradeableProxy } from "@openzeppelin/contracts/proxy/transparent/TransparentUpgradeableProxy.sol";
+
+import { RedstoneAdapterPriceOracle } from "../../oracles/default/RedstoneAdapterPriceOracle.sol";
+
+import { BaseTest } from "../config/BaseTest.t.sol";
+
+contract RedstoneAdapterOracleTest is BaseTest {
+  RedstoneAdapterPriceOracle public oracle;
+  address public redstoneOracleAddress;
+  address MODE_USDC = 0xd988097fb8612cc24eeC14542bC03424c656005f;
+  address MODE_EZETH = 0x2416092f143378750bb29b79eD961ab195CcEea5;
+  address MODE_WBTC = 0xcDd475325D6F564d27247D1DddBb0DAc6fA0a5CF;
+
+  function afterForkSetUp() internal override {
+    if (block.chainid == MODE_MAINNET) {
+      redstoneOracleAddress = 0x7C1DAAE7BB0688C9bfE3A918A4224041c7177256;
+    }
+
+    oracle = new RedstoneAdapterPriceOracle(redstoneOracleAddress);
+  }
+
+  function testPrintPricesMode() public fork(MODE_MAINNET) {
+    emit log_named_uint("ezETH price (18 dec)", oracle.price(MODE_EZETH));
+    emit log_named_uint("WBTC price (8 dec)", oracle.price(MODE_WBTC));
+  }
+}