feat: use CurveStableSwapMetaNG contract

packages/contracts/migrations/development/Deploy001_Diamond_Dollar.s.sol

@@ -13,19 +13,18 @@ import {DiamondCutFacet} from "../../src/dollar/facets/DiamondCutFacet.sol";
 import {DiamondLoupeFacet} from "../../src/dollar/facets/DiamondLoupeFacet.sol";
 import {ManagerFacet} from "../../src/dollar/facets/ManagerFacet.sol";
 import {OwnershipFacet} from "../../src/dollar/facets/OwnershipFacet.sol";
-import {TWAPOracleDollar3poolFacet} from "../../src/dollar/facets/TWAPOracleDollar3poolFacet.sol";
 import {UbiquityPoolFacet} from "../../src/dollar/facets/UbiquityPoolFacet.sol";
+import {ICurveStableSwapMetaNG} from "../../src/dollar/interfaces/ICurveStableSwapMetaNG.sol";
 import {IDiamondCut} from "../../src/dollar/interfaces/IDiamondCut.sol";
 import {IDiamondLoupe} from "../../src/dollar/interfaces/IDiamondLoupe.sol";
 import {IERC173} from "../../src/dollar/interfaces/IERC173.sol";
-import {IMetaPool} from "../../src/dollar/interfaces/IMetaPool.sol";
 import {DEFAULT_ADMIN_ROLE, DOLLAR_TOKEN_MINTER_ROLE, DOLLAR_TOKEN_BURNER_ROLE, PAUSER_ROLE} from "../../src/dollar/libraries/Constants.sol";
 import {LibAccessControl} from "../../src/dollar/libraries/LibAccessControl.sol";
 import {AppStorage, LibAppStorage, Modifiers} from "../../src/dollar/libraries/LibAppStorage.sol";
 import {LibDiamond} from "../../src/dollar/libraries/LibDiamond.sol";
 import {MockChainLinkFeed} from "../../src/dollar/mocks/MockChainLinkFeed.sol";
+import {MockCurveStableSwapMetaNG} from "../../src/dollar/mocks/MockCurveStableSwapMetaNG.sol";
 import {MockERC20} from "../../src/dollar/mocks/MockERC20.sol";
-import {MockMetaPool} from "../../src/dollar/mocks/MockMetaPool.sol";
 import {DiamondTestHelper} from "../../test/helpers/DiamondTestHelper.sol";
 
 /**
@@ -117,21 +116,19 @@ contract Deploy001_Diamond_Dollar is Script, DiamondTestHelper {
     DiamondLoupeFacet diamondLoupeFacetImplementation;
     ManagerFacet managerFacetImplementation;
     OwnershipFacet ownershipFacetImplementation;
-    TWAPOracleDollar3poolFacet twapOracleDollar3PoolFacetImplementation;
     UbiquityPoolFacet ubiquityPoolFacetImplementation;
 
     // oracle related contracts
     AggregatorV3Interface chainLinkPriceFeedLusd; // chainlink LUSD/USD price feed
     IERC20 curveTriPoolLpToken; // Curve's 3CRV-LP token
-    IMetaPool curveDollarMetaPool; // Curve's Dollar-3CRVLP metapool
+    ICurveStableSwapMetaNG curveDollarMetaPool; // Curve's Dollar-3CRVLP metapool
 
     // selectors for all of the facets
     bytes4[] selectorsOfAccessControlFacet;
     bytes4[] selectorsOfDiamondCutFacet;
     bytes4[] selectorsOfDiamondLoupeFacet;
     bytes4[] selectorsOfManagerFacet;
     bytes4[] selectorsOfOwnershipFacet;
-    bytes4[] selectorsOfTWAPOracleDollar3poolFacet;
     bytes4[] selectorsOfUbiquityPoolFacet;
 
     function run() public virtual {
@@ -166,9 +163,6 @@ contract Deploy001_Diamond_Dollar is Script, DiamondTestHelper {
         selectorsOfOwnershipFacet = getSelectorsFromAbi(
             "/out/OwnershipFacet.sol/OwnershipFacet.json"
         );
-        selectorsOfTWAPOracleDollar3poolFacet = getSelectorsFromAbi(
-            "/out/TWAPOracleDollar3poolFacet.sol/TWAPOracleDollar3poolFacet.json"
-        );
         selectorsOfUbiquityPoolFacet = getSelectorsFromAbi(
             "/out/UbiquityPoolFacet.sol/UbiquityPoolFacet.json"
         );
@@ -179,7 +173,6 @@ contract Deploy001_Diamond_Dollar is Script, DiamondTestHelper {
         diamondLoupeFacetImplementation = new DiamondLoupeFacet();
         managerFacetImplementation = new ManagerFacet();
         ownershipFacetImplementation = new OwnershipFacet();
-        twapOracleDollar3PoolFacetImplementation = new TWAPOracleDollar3poolFacet();
         ubiquityPoolFacetImplementation = new UbiquityPoolFacet();
 
         // prepare DiamondInit args
@@ -198,7 +191,7 @@ contract Deploy001_Diamond_Dollar is Script, DiamondTestHelper {
         });
 
         // prepare facet cuts
-        FacetCut[] memory cuts = new FacetCut[](7);
+        FacetCut[] memory cuts = new FacetCut[](6);
         cuts[0] = (
             FacetCut({
                 facetAddress: address(accessControlFacetImplementation),
@@ -235,13 +228,6 @@ contract Deploy001_Diamond_Dollar is Script, DiamondTestHelper {
             })
         );
         cuts[5] = (
-            FacetCut({
-                facetAddress: address(twapOracleDollar3PoolFacetImplementation),
-                action: FacetCutAction.Add,
-                functionSelectors: selectorsOfTWAPOracleDollar3poolFacet
-            })
-        );
-        cuts[6] = (
             FacetCut({
                 facetAddress: address(ubiquityPoolFacetImplementation),
                 action: FacetCutAction.Add,
@@ -438,7 +424,7 @@ contract Deploy001_Diamond_Dollar is Script, DiamondTestHelper {
         );
 
         // deploy mock Curve's Dollar-3CRVLP metapool
-        curveDollarMetaPool = new MockMetaPool(
+        curveDollarMetaPool = new MockCurveStableSwapMetaNG(
             address(dollarToken),
             address(curveTriPoolLpToken)
         );
@@ -450,23 +436,15 @@ contract Deploy001_Diamond_Dollar is Script, DiamondTestHelper {
         // Curve's Dollar-3CRVLP metapool setup
         //========================================
 
-        // start sending owner transactions
-        vm.startBroadcast(ownerPrivateKey);
-
-        TWAPOracleDollar3poolFacet twapOracleDollar3PoolFacet = TWAPOracleDollar3poolFacet(
-                address(diamond)
-            );
+        // start sending admin transactions
+        vm.startBroadcast(adminPrivateKey);
 
-        // set Curve Dollar-3CRVLP pool in the diamond storage
-        twapOracleDollar3PoolFacet.setPool(
-            address(curveDollarMetaPool),
-            address(curveTriPoolLpToken)
-        );
+        ManagerFacet managerFacet = ManagerFacet(address(diamond));
 
-        // fetch latest Dollar price from Curve's Dollar-3CRVLP metapool
-        twapOracleDollar3PoolFacet.update();
+        // set curve's metapool in manager facet
+        managerFacet.setStableSwapMetaPoolAddress(address(curveDollarMetaPool));
 
-        // stop sending owner transactions
+        // stop sending admin transactions
         vm.stopBroadcast();
     }
 }

packages/contracts/migrations/mainnet/Deploy001_Diamond_Dollar.s.sol

@@ -4,9 +4,9 @@ pragma solidity 0.8.19;
 import {AggregatorV3Interface} from "@chainlink/interfaces/AggregatorV3Interface.sol";
 import {IERC20} from "@openzeppelin/contracts/interfaces/IERC20.sol";
 import {Deploy001_Diamond_Dollar as Deploy001_Diamond_Dollar_Development} from "../development/Deploy001_Diamond_Dollar.s.sol";
-import {TWAPOracleDollar3poolFacet} from "../../src/dollar/facets/TWAPOracleDollar3poolFacet.sol";
+import {ManagerFacet} from "../../src/dollar/facets/ManagerFacet.sol";
 import {UbiquityPoolFacet} from "../../src/dollar/facets/UbiquityPoolFacet.sol";
-import {IMetaPool} from "../../src/dollar/interfaces/IMetaPool.sol";
+import {ICurveStableSwapMetaNG} from "../../src/dollar/interfaces/ICurveStableSwapMetaNG.sol";
 
 /// @notice Migration contract
 contract Deploy001_Diamond_Dollar is Deploy001_Diamond_Dollar_Development {
@@ -82,31 +82,22 @@ contract Deploy001_Diamond_Dollar is Deploy001_Diamond_Dollar_Development {
         // Curve's Dollar-3CRVLP metapool setup
         //========================================
 
-        // start sending owner transactions
-        vm.startBroadcast(ownerPrivateKey);
+        // start sending admin transactions
+        vm.startBroadcast(adminPrivateKey);
 
         // init 3CRV token
         curveTriPoolLpToken = IERC20(token3CrvAddress);
 
         // init Dollar-3CRVLP Curve metapool
-        curveDollarMetaPool = IMetaPool(curveDollarMetapoolAddress);
-
-        /*
-        TODO: uncomment when we redeploy Curve's Dollar-3CRV metapool with the new Dollar token
-
-        TWAPOracleDollar3poolFacet twapOracleDollar3PoolFacet = TWAPOracleDollar3poolFacet(address(diamond));
-
-        // set Curve Dollar-3CRVLP pool in the diamond storage
-        twapOracleDollar3PoolFacet.setPool(
-            address(curveDollarMetaPool),
-            address(curveTriPoolLpToken)
+        curveDollarMetaPool = ICurveStableSwapMetaNG(
+            curveDollarMetapoolAddress
         );
 
-        // fetch latest Dollar price from Curve's Dollar-3CRVLP metapool
-        twapOracleDollar3PoolFacet.update();
-        */
+        // set curve's metapool in manager facet
+        ManagerFacet managerFacet = ManagerFacet(address(diamond));
+        managerFacet.setStableSwapMetaPoolAddress(address(curveDollarMetaPool));
 
-        // stop sending owner transactions
+        // stop sending admin transactions
         vm.stopBroadcast();
     }
 }

packages/contracts/src/deprecated/TWAPOracle.sol

@@ -1,7 +1,7 @@
 // SPDX-License-Identifier: Apache-2.0
 pragma solidity ^0.8.3;
 
-import "../dollar/interfaces/IMetaPool.sol";
+import "./interfaces/IMetaPool.sol";
 
 contract TWAPOracle {
     address public immutable pool;

packages/contracts/src/deprecated/UbiquityAlgorithmicDollarManager.sol

@@ -6,9 +6,9 @@ import "@openzeppelin/contracts/token/ERC20/ERC20.sol";
 import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
 import "@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol";
 
+import "./interfaces/IMetaPool.sol";
 import "./interfaces/IUbiquityAlgorithmicDollar.sol";
 import "../dollar/interfaces/ICurveFactory.sol";
-import "../dollar/interfaces/IMetaPool.sol";
 
 import "./TWAPOracle.sol";
 

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

@@ -7,7 +7,7 @@ import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
 
 import "../../dollar/interfaces/IUbiquityDollarToken.sol";
 import "../../dollar/interfaces/ICurveFactory.sol";
-import "../../dollar/interfaces/IMetaPool.sol";
+import "../../dollar/interfaces/ICurveStableSwapMetaNG.sol";
 import "../libraries/LibAccessControl.sol";
 
 /**
@@ -246,8 +246,10 @@ contract ManagerFacet is Modifiers {
 
         // coin at index 0 is Dollar and index 1 is 3CRV
         require(
-            IMetaPool(metaPool).coins(0) == store.dollarTokenAddress &&
-                IMetaPool(metaPool).coins(1) == _crv3PoolTokenAddress,
+            ICurveStableSwapMetaNG(metaPool).coins(0) ==
+                store.dollarTokenAddress &&
+                ICurveStableSwapMetaNG(metaPool).coins(1) ==
+                _crv3PoolTokenAddress,
             "MGR: COIN_ORDER_MISMATCH"
         );
         // Add the initial liquidity to the StableSwap meta pool
@@ -257,7 +259,7 @@ contract ManagerFacet is Modifiers {
         ];
         // set curve 3Pool address
         store.curve3PoolTokenAddress = _crv3PoolTokenAddress;
-        IMetaPool(metaPool).add_liquidity(amounts, 0, msg.sender);
+        ICurveStableSwapMetaNG(metaPool).add_liquidity(amounts, 0, msg.sender);
     }
 
     /**

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

@@ -0,0 +1,99 @@
+// SPDX-License-Identifier: MIT
+pragma solidity 0.8.19;
+
+import {IERC20} from "@openzeppelin/contracts/interfaces/IERC20.sol";
+
+/**
+ * @notice Curve MetaPool interface
+ *
+ * @notice **What is Curve MetaPool**
+ * @notice The pool that consists of 2 tokens: stable coin and 3CRV LP token.
+ * For example the pool may contain Ubiquity Dollar and 3CRV LP token.
+ * This allows users to trade between Ubiquity Dollar and any of the tokens
+ * from the Curve 3Pool (DAI, USDC, USDT). When user adds liquidity to the pool
+ * then he is rewarded with MetaPool LP tokens. 1 Dollar3CRV LP token != 1 stable coin token.
+ * @notice Add liquidity example:
+ * 1. User sends 100 Ubiquity Dollars to the pool
+ * 2. User gets 100 Dollar3CRV LP tokens of the pool
+ * @notice Remove liquidity example:
+ * 1. User sends 100 Dollar3CRV LP tokens to the pool
+ * 2. User gets 100 Dollar/DAI/USDC/USDT (may choose any) tokens
+ *
+ * @dev Source: https://github.com/curvefi/stableswap-ng/blob/bff1522b30819b7b240af17ccfb72b0effbf6c47/contracts/main/CurveStableSwapMetaNG.vy
+ * @dev Docs: https://docs.curve.fi/stableswap-exchange/stableswap-ng/pools/metapool/
+ */
+interface ICurveStableSwapMetaNG is IERC20 {
+    /**
+     * @notice Deposits coins into to the pool and mints new LP tokens
+     * @param _amounts List of amounts of underlying coins to deposit.
+     * Amounts correspond to the tokens at the same index locations within `coins`.
+     * @param _min_mint_amount Minimum amount of LP tokens to mint from the deposit
+     * @param _receiver Optional address that receives the LP tokens. If not specified, they are sent to the caller.
+     * @return The amount of LP tokens that were minted in the deposit
+     */
+    function add_liquidity(
+        uint256[2] memory _amounts,
+        uint256 _min_mint_amount,
+        address _receiver
+    ) external returns (uint256);
+
+    /**
+     * @notice Estimates the amount of LP tokens minted or burned based on a deposit or withdrawal
+     *
+     * @notice This calculation accounts for slippage, but not fees. It should be used as a basis for
+     * determining expected amounts when calling `add_liquidity()` or `remove_liquidity_imbalance()`,
+     * but should not be considered to be precise!
+     *
+     * @param _amounts Amount of each coin being deposited. Amounts correspond to the tokens at the
+     * same index locations within `coins()`.
+     * @param _is_deposit Set `True` for deposits, `False` for withdrawals
+     * @return The expected amount of LP tokens minted or burned
+     */
+    function calc_token_amount(
+        uint256[2] memory _amounts,
+        bool _is_deposit
+    ) external view returns (uint256);
+
+    /**
+     * @notice Returns token address by the provided `arg0` index
+     * @param arg0 Token index
+     * @return Token address
+     */
+    function coins(uint256 arg0) external view returns (address);
+
+    /**
+     * @notice Performs an exchange between two tokens. Index values can be found
+     * using the `coins()` public getter method, or `get_coins()` within the factory contract.
+     * @param i Index value of the token to send
+     * @param j Index value of the token to receive
+     * @param dx The amount of `i` being exchanged
+     * @param min_dy The minimum amount of `j` to receive. If the swap would result in less, the transaction will revert.
+     * @return The amount of `j` received in the exchange
+     */
+    function exchange(
+        int128 i,
+        int128 j,
+        uint256 dx,
+        uint256 min_dy
+    ) external returns (uint256);
+
+    /**
+     * @notice Function to calculate the exponential moving average (ema) price for the coin at index value `i`
+     * @param i Index value of coin
+     * @return Price oracle
+     */
+    function price_oracle(uint256 i) external view returns (uint256);
+
+    /**
+     * @notice Withdraws a single asset from the pool
+     * @param _burn_amount Amount of LP tokens to burn in the withdrawal
+     * @param i Index value of the coin to withdraw. Can be found using the `coins()` getter method.
+     * @param _min_received Minimum amount of the coin to receive
+     * @return The amount of the coin received in the withdrawal
+     */
+    function remove_liquidity_one_coin(
+        uint256 _burn_amount,
+        int128 i,
+        uint256 _min_received
+    ) external returns (uint256);
+}