[WIP] Replace DAI with USDS

contracts/contracts/harvest/OETHHarvesterSimple.sol

@@ -1,4 +1,4 @@
-// SPDX-License-Identifier: BUSL-1.1
+// SPDX-License-Identifier: MIT
 pragma solidity ^0.8.0;
 
 import { Strategizable } from "../governance/Strategizable.sol";

contracts/contracts/harvest/SuperOETHHarvester.sol

@@ -1,4 +1,4 @@
-// SPDX-License-Identifier: BUSL-1.1
+// SPDX-License-Identifier: MIT
 pragma solidity ^0.8.0;
 
 import { OETHHarvesterSimple, IERC20, IStrategy, SafeERC20 } from "./OETHHarvesterSimple.sol";

contracts/contracts/interfaces/IVault.sol

@@ -105,7 +105,7 @@ interface IVault {
     function setOracleSlippage(address _asset, uint16 _allowedOracleSlippageBps)
         external;
 
-    function supportAsset(address _asset, uint8 _supportsAsset) external;
+    function supportAsset(address _asset, uint8 _unitConversion) external;
 
     function approveStrategy(address _addr) external;
 

contracts/contracts/oracle/OracleRouter.sol

@@ -28,6 +28,17 @@ contract OracleRouter is AbstractOracleRouter {
             // Chainlink: DAI/USD
             feedAddress = 0xAed0c38402a5d19df6E4c03F4E2DceD6e29c1ee9;
             maxStaleness = 1 hours + STALENESS_BUFFER;
+        } else if (asset == 0xdC035D45d973E3EC169d2276DDab16f1e407384F) {
+            // https://data.chain.link/ethereum/mainnet/stablecoins/dai-usd
+            // Chainlink: DAI/USD
+            feedAddress = 0xAed0c38402a5d19df6E4c03F4E2DceD6e29c1ee9;
+            maxStaleness = 1 hours + STALENESS_BUFFER;
+            // } else if (asset == 0xdC035D45d973E3EC169d2276DDab16f1e407384F) {
+            // solhint-disable-next-line
+            //     // https://chroniclelabs.org/dashboard/oracle/USDS/USD?blockchain=ETH&txn=0x963edc177ee0cb8e5ecdb39b535b800c5037b2e2fc20b335e44a95a979d4719a&contract=0x74661a9ea74fD04975c6eBc6B155Abf8f885636c
+            //     // Chronicle: USDS/USD
+            //     feedAddress = 0x74661a9ea74fD04975c6eBc6B155Abf8f885636c;
+            //     maxStaleness = 1 hours + STALENESS_BUFFER;
         } else if (asset == 0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48) {
             // https://data.chain.link/ethereum/mainnet/stablecoins/usdc-usd
             // Chainlink: USDC/USD

contracts/contracts/proxies/BaseProxies.sol

@@ -1,4 +1,4 @@
-// SPDX-License-Identifier: BUSL-1.1
+// SPDX-License-Identifier: MIT
 pragma solidity ^0.8.0;
 
 import { InitializeGovernedUpgradeabilityProxy } from "./InitializeGovernedUpgradeabilityProxy.sol";

contracts/contracts/proxies/Proxies.sol

@@ -1,4 +1,4 @@
-// SPDX-License-Identifier: BUSL-1.1
+// SPDX-License-Identifier: MIT
 pragma solidity ^0.8.0;
 
 import { InitializeGovernedUpgradeabilityProxy } from "./InitializeGovernedUpgradeabilityProxy.sol";
@@ -332,3 +332,10 @@ contract PoolBoostCentralRegistryProxy is
 {
 
 }
+
+/**
+ * @notice MakerSSRStrategyProxy delegates calls to a Generalized4626Strategy implementation
+ */
+contract MakerSSRStrategyProxy is InitializeGovernedUpgradeabilityProxy {
+
+}

contracts/contracts/strategies/DAIMigratorStrategy.sol

@@ -0,0 +1,126 @@
+// SPDX-License-Identifier: MIT
+pragma solidity ^0.8.0;
+
+import { InitializableAbstractStrategy } from "../utils/InitializableAbstractStrategy.sol";
+import { IERC20 } from "@openzeppelin/contracts/token/ERC20/IERC20.sol";
+
+interface IDaiUsdsMigrationContract {
+    function daiToUsds(address usr, uint256 wad) external;
+
+    function usdsToDai(address usr, uint256 wad) external;
+}
+
+contract DAIMigrationStrategy is InitializableAbstractStrategy {
+    address public immutable dai;
+    address public immutable usds;
+
+    constructor(
+        BaseStrategyConfig memory _baseConfig,
+        address _dai,
+        address _usds
+    ) InitializableAbstractStrategy(_baseConfig) {
+        dai = _dai;
+        usds = _usds;
+    }
+
+    function initialize(address _governorAddr)
+        external
+        onlyGovernor
+        initializer
+    {
+        _setGovernor(_governorAddr);
+
+        address[] memory rewardTokens = new address[](0);
+        address[] memory assets = new address[](2);
+        address[] memory pTokens = new address[](2);
+
+        assets[0] = address(dai);
+        assets[1] = address(usds);
+        pTokens[0] = address(dai);
+        pTokens[1] = address(usds);
+
+        InitializableAbstractStrategy._initialize(
+            rewardTokens,
+            assets,
+            pTokens
+        );
+    }
+
+    function deposit(address _asset, uint256 _amount)
+        external
+        override
+        onlyVault
+        nonReentrant
+    {
+        _deposit(_asset, _amount);
+    }
+
+    function depositAll() external override onlyVault nonReentrant {
+        _deposit(dai, IERC20(dai).balanceOf(address(this)));
+    }
+
+    function _deposit(address _asset, uint256 _amount) internal {
+        // You can only deposit DAI
+        require(_asset == dai, "Only DAI can be deposited");
+        require(_amount > 0, "Must deposit something");
+
+        IERC20(dai).approve(platformAddress, _amount);
+        IDaiUsdsMigrationContract(platformAddress).daiToUsds(
+            address(this),
+            _amount
+        );
+    }
+
+    function withdraw(
+        address _recipient,
+        address _asset,
+        uint256 _amount
+    ) external override onlyVault nonReentrant {
+        _withdraw(_recipient, _asset, _amount);
+    }
+
+    function withdrawAll() external override onlyVaultOrGovernor nonReentrant {
+        _withdraw(vaultAddress, usds, IERC20(usds).balanceOf(address(this)));
+    }
+
+    function _withdraw(
+        address _recipient,
+        address _asset,
+        uint256 _amount
+    ) internal {
+        // You can only withdraw USDS
+        require(_asset == usds, "Unsupported asset");
+        require(_amount > 0, "Must withdraw something");
+        require(_recipient == vaultAddress, "Only the vault can withdraw");
+        IERC20(usds).transfer(_recipient, _amount);
+    }
+
+    function checkBalance(address _asset)
+        external
+        view
+        override
+        returns (uint256 balance)
+    {
+        if (_asset == dai) {
+            // Contract should not have any DAI at any point of time.
+            return 0;
+        } else if (_asset == usds) {
+            balance = IERC20(usds).balanceOf(address(this));
+        } else {
+            revert("Unsupported asset");
+        }
+    }
+
+    function supportsAsset(address _asset) public view override returns (bool) {
+        return _asset == dai || _asset == usds;
+    }
+
+    function collectRewardTokens() external override {}
+
+    function _abstractSetPToken(address _asset, address _pToken)
+        internal
+        override
+    {}
+
+    function safeApproveAllTokens() external override {}
+}