Bugfix/fix collateral twap

.gitmodules

@@ -34,3 +34,7 @@
 	path = packages/contracts/lib/openzeppelin-contracts-upgradeable
 	url = https://github.com/OpenZeppelin/openzeppelin-contracts-upgradeable
 	branch = release-v4.9
+[submodule "packages/contracts/lib/chainlink-brownie-contracts"]
+	path = packages/contracts/lib/chainlink-brownie-contracts
+	url = https://github.com/smartcontractkit/chainlink-brownie-contracts
+	branch= main

packages/contracts/remappings.txt

@@ -8,3 +8,4 @@ solidity-linked-list/=lib/solidity-linked-list
 @uniswap/v3-periphery/contracts/=lib/Uniswap/v3-periphery/contracts
 abdk/=lib/abdk-libraries-solidity/
 operator-filter-registry/=lib/operator-filter-registry/src
+@chainlink/=lib/chainlink-brownie-contracts/contracts/src/v0.8/

packages/contracts/src/dollar/facets/UbiquityPoolFacet.sol

@@ -110,6 +110,11 @@ contract UbiquityPoolFacet is IUbiquityPool, Modifiers {
         return LibUbiquityPool.collectRedemption(collateralIndex);
     }
 
+    /// @inheritdoc IUbiquityPool
+    function updateChainLinkCollateralPrice(uint256 collateralIndex) external {
+        LibUbiquityPool.updateChainLinkCollateralPrice(collateralIndex);
+    }
+
     //=========================
     // AMO minters functions
     //=========================
@@ -131,9 +136,14 @@ contract UbiquityPoolFacet is IUbiquityPool, Modifiers {
     /// @inheritdoc IUbiquityPool
     function addCollateralToken(
         address collateralAddress,
+        address chainLinkPriceFeedAddress,
         uint256 poolCeiling
     ) external onlyAdmin {
-        LibUbiquityPool.addCollateralToken(collateralAddress, poolCeiling);
+        LibUbiquityPool.addCollateralToken(
+            collateralAddress,
+            chainLinkPriceFeedAddress,
+            poolCeiling
+        );
     }
 
     /// @inheritdoc IUbiquityPool
@@ -142,11 +152,16 @@ contract UbiquityPoolFacet is IUbiquityPool, Modifiers {
     }
 
     /// @inheritdoc IUbiquityPool
-    function setCollateralPrice(
-        uint256 collateralIndex,
-        uint256 newPrice
+    function setCollateralChainLinkPriceFeed(
+        address collateralAddress,
+        address chainLinkPriceFeedAddress,
+        uint256 stalenessThreshold
     ) external onlyAdmin {
-        LibUbiquityPool.setCollateralPrice(collateralIndex, newPrice);
+        LibUbiquityPool.setCollateralChainLinkPriceFeed(
+            collateralAddress,
+            chainLinkPriceFeedAddress,
+            stalenessThreshold
+        );
     }
 
     /// @inheritdoc IUbiquityPool

packages/contracts/src/dollar/interfaces/IUbiquityPool.sol

@@ -142,10 +142,12 @@ interface IUbiquityPool {
     /**
      * @notice Adds a new collateral token
      * @param collateralAddress Collateral token address
+     * @param chainLinkPriceFeedAddress Chainlink's price feed address
      * @param poolCeiling Max amount of available tokens for collateral
      */
     function addCollateralToken(
         address collateralAddress,
+        address chainLinkPriceFeedAddress,
         uint256 poolCeiling
     ) external;
 
@@ -156,15 +158,23 @@ interface IUbiquityPool {
     function removeAmoMinter(address amoMinterAddress) external;
 
     /**
-     * @notice Sets collateral token price in USD
-     * @param collateralIndex Collateral token index
-     * @param newPrice New USD price (precision 1e6)
+     * @notice Sets collateral ChainLink price feed params
+     * @param collateralAddress Collateral token address
+     * @param chainLinkPriceFeedAddress ChainLink price feed address
+     * @param stalenessThreshold Threshold in seconds when chainlink answer should be considered stale
      */
-    function setCollateralPrice(
-        uint256 collateralIndex,
-        uint256 newPrice
+    function setCollateralChainLinkPriceFeed(
+        address collateralAddress,
+        address chainLinkPriceFeedAddress,
+        uint256 stalenessThreshold
     ) external;
 
+    /**
+     * @notice Updates collateral token price in USD from ChainLink price feed
+     * @param collateralIndex Collateral token index
+     */
+    function updateChainLinkCollateralPrice(uint256 collateralIndex) external;
+
     /**
      * @notice Sets mint and redeem fees, 1_000_000 = 100%
      * @param collateralIndex Collateral token index

packages/contracts/src/dollar/libraries/LibUbiquityPool.sol

@@ -1,6 +1,7 @@
 // SPDX-License-Identifier: GPL-2.0-or-later
 pragma solidity 0.8.19;
 
+import {AggregatorV3Interface} from "@chainlink/interfaces/AggregatorV3Interface.sol";
 import {ERC20} from "@openzeppelin/contracts/token/ERC20/ERC20.sol";
 import {IERC20} from "@openzeppelin/contracts/token/ERC20/IERC20.sol";
 import {SafeERC20} from "@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol";
@@ -41,43 +42,47 @@
         address[] collateralAddresses;
         // collateral address -> collateral index
         mapping(address collateralAddress => uint256 collateralIndex) collateralIndex;
-        // Stores price of the collateral, if price is paused. CONSIDER ORACLES EVENTUALLY!!!
+        // collateral index -> chainlink price feed addresses
+        address[] collateralPriceFeedAddresses;
+        // collateral index -> threshold in seconds when chainlink answer should be considered stale
+        uint256[] collateralPriceFeedStalenessThresholds;
+        // collateral index -> collateral price
         uint256[] collateralPrices;
         // array collateral symbols
         string[] collateralSymbols;
         // collateral address -> is it enabled
         mapping(address collateralAddress => bool isEnabled) isCollateralEnabled;
         // Number of decimals needed to get to E18. collateral index -> missing decimals
         uint256[] missingDecimals;
         // Total across all collaterals. Accounts for missing_decimals
         uint256[] poolCeilings;
         //====================
         // Redeem related
         //====================
         // user -> block number (collateral independent)
         mapping(address => uint256) lastRedeemedBlock;
         // 1010000 = $1.01
         uint256 mintPriceThreshold;
         // 990000 = $0.99
         uint256 redeemPriceThreshold;
         // address -> collateral index -> balance
         mapping(address user => mapping(uint256 collateralIndex => uint256 amount)) redeemCollateralBalances;
         // number of blocks to wait before being able to collectRedemption()
         uint256 redemptionDelayBlocks;
         // collateral index -> balance
         uint256[] unclaimedPoolCollateral;
         //================
         // Fees related
         //================
         // minting fee of a particular collateral index, 1_000_000 = 100%
         uint256[] mintingFee;
         // redemption fee of a particular collateral index, 1_000_000 = 100%
         uint256[] redemptionFee;
         //=================
         // Pause related
         //=================
         // whether borrowing collateral by AMO minters is paused for a particular collateral index
         bool[] isBorrowPaused;
         // whether minting is paused for a particular collateral index
         bool[] isMintPaused;
         // whether redeeming is paused for a particular collateral index
@@ -89,6 +94,8 @@
         uint256 index;
         string symbol;
         address collateralAddress;
+        address collateralPriceFeedAddress;
+        uint256 collateralPriceFeedStalenessThreshold;
         bool isEnabled;
         uint256 missingDecimals;
         uint256 price;
@@ -123,6 +130,12 @@
     event AmoMinterAdded(address amoMinterAddress);
     /// @notice Emitted when AMO minter is removed
     event AmoMinterRemoved(address amoMinterAddress);
+    /// @notice Emitted on setting a chainlink's collateral price feed params
+    event CollateralPriceFeedSet(
+        uint256 collateralIndex,
+        address priceFeedAddress,
+        uint256 stalenessThreshold
+    );
     /// @notice Emitted on setting a collateral price
     event CollateralPriceSet(uint256 collateralIndex, uint256 newPrice);
     /// @notice Emitted on enabling/disabling a particular collateral token
@@ -213,6 +226,8 @@
             index,
             poolStorage.collateralSymbols[index],
             collateralAddress,
+            poolStorage.collateralPriceFeedAddresses[index],
+            poolStorage.collateralPriceFeedStalenessThresholds[index],
             poolStorage.isCollateralEnabled[collateralAddress],
             poolStorage.missingDecimals[index],
             poolStorage.collateralPrices[index],
@@ -325,13 +340,18 @@
             "Minting is paused"
         );
 
+        // update Dollar price from Curve's Dollar Metapool
+        LibTWAPOracle.update();
         // prevent unnecessary mints
         require(
             getDollarPriceUsd() >= poolStorage.mintPriceThreshold,
             "Dollar price too low"
         );
 
-        // get amount of collateral for incoming Dollars
+        // update collateral price
+        updateChainLinkCollateralPrice(collateralIndex);
+
+        // get amount of collateral for minting Dollars
         collateralNeeded = getDollarInCollateral(collateralIndex, dollarAmount);
 
         // subtract the minting fee
@@ -392,6 +412,8 @@
             "Redeeming is paused"
         );
 
+        // update Dollar price from Curve's Dollar Metapool
+        LibTWAPOracle.update();
         // prevent unnecessary redemptions that could adversely affect the Dollar price
         require(
             getDollarPriceUsd() <= poolStorage.redeemPriceThreshold,
@@ -405,6 +427,11 @@
                 )
             )
             .div(UBIQUITY_POOL_PRICE_PRECISION);
+
+        // update collateral price
+        updateChainLinkCollateralPrice(collateralIndex);
+
+        // get collateral output for incoming Dollars
         collateralOut = getDollarInCollateral(collateralIndex, dollarAfterFee);
 
         // checks
@@ -489,6 +516,51 @@
         }
     }
 
+    /**
+     * @notice Updates collateral token price in USD from ChainLink price feed
+     * @param collateralIndex Collateral token index
+     */
+    function updateChainLinkCollateralPrice(uint256 collateralIndex) internal {
+        UbiquityPoolStorage storage poolStorage = ubiquityPoolStorage();
+
+        AggregatorV3Interface priceFeed = AggregatorV3Interface(
+            poolStorage.collateralPriceFeedAddresses[collateralIndex]
+        );
+
+        // fetch latest price
+        (
+            ,
+            // roundId
+            int256 answer, // startedAt
+            ,
+            uint256 updatedAt,
+
+        ) = // answeredInRound
+            priceFeed.latestRoundData();
+
+        // fetch number of decimals in chainlink feed
+        uint256 priceFeedDecimals = priceFeed.decimals();
+
+        // validation
+        require(answer > 0, "Invalid price");
+        require(
+            block.timestamp - updatedAt <
+                poolStorage.collateralPriceFeedStalenessThresholds[
+                    collateralIndex
+                ],
+            "Stale data"
+        );
+
+        // convert chainlink price to 6 decimals
+        uint256 price = uint256(answer).mul(UBIQUITY_POOL_PRICE_PRECISION).div(
+            10 ** priceFeedDecimals
+        );
+
+        poolStorage.collateralPrices[collateralIndex] = price;
+
+        emit CollateralPriceSet(collateralIndex, price);
+    }
+
     //=========================
     // AMO minters functions
     //=========================
@@ -551,10 +623,12 @@
     /**
      * @notice Adds a new collateral token
      * @param collateralAddress Collateral token address
+     * @param chainLinkPriceFeedAddress Chainlink's price feed address
      * @param poolCeiling Max amount of available tokens for collateral
      */
     function addCollateralToken(
         address collateralAddress,
+        address chainLinkPriceFeedAddress,
         uint256 poolCeiling
     ) internal {
         UbiquityPoolStorage storage poolStorage = ubiquityPoolStorage();
@@ -593,8 +667,16 @@
         poolStorage.isRedeemPaused.push(false);
         poolStorage.isBorrowPaused.push(false);
 
-        // pool ceiling
+        // set pool ceiling
         poolStorage.poolCeilings.push(poolCeiling);
+
+        // set price feed address
+        poolStorage.collateralPriceFeedAddresses.push(
+            chainLinkPriceFeedAddress
+        );
+
+        // set price feed staleness threshold in seconds
+        poolStorage.collateralPriceFeedStalenessThresholds.push(1 days);
     }
 
     /**
@@ -610,20 +692,37 @@
     }
 
     /**
-     * @notice Sets collateral token price in USD
-     * @param collateralIndex Collateral token index
-     * @param newPrice New USD price (precision 1e6)
+     * @notice Sets collateral ChainLink price feed params
+     * @param collateralAddress Collateral token address
+     * @param chainLinkPriceFeedAddress ChainLink price feed address
+     * @param stalenessThreshold Threshold in seconds when chainlink answer should be considered stale
      */
-    function setCollateralPrice(
-        uint256 collateralIndex,
-        uint256 newPrice
+    function setCollateralChainLinkPriceFeed(
+        address collateralAddress,
+        address chainLinkPriceFeedAddress,
+        uint256 stalenessThreshold
     ) internal {
         UbiquityPoolStorage storage poolStorage = ubiquityPoolStorage();
 
-        // Notice: CONSIDER ORACLES EVENTUALLY!!!
-        poolStorage.collateralPrices[collateralIndex] = newPrice;
+        uint256 collateralIndex = poolStorage.collateralIndex[
+            collateralAddress
+        ];
+
+        // set price feed address
+        poolStorage.collateralPriceFeedAddresses[
+            collateralIndex
+        ] = chainLinkPriceFeedAddress;
 
-        emit CollateralPriceSet(collateralIndex, newPrice);
+        // set staleness threshold in seconds when chainlink answer should be considered stale
+        poolStorage.collateralPriceFeedStalenessThresholds[
+            collateralIndex
+        ] = stalenessThreshold;
+
+        emit CollateralPriceFeedSet(
+            collateralIndex,
+            chainLinkPriceFeedAddress,
+            stalenessThreshold
+        );
     }
 
     /**