Merge branch 'mUSD-migration' into master-v2

contracts/masset/mUSD/Migrator.sol

@@ -0,0 +1,65 @@
+// SPDX-License-Identifier: AGPL-3.0-or-later
+pragma solidity 0.8.0;
+pragma abicoder v2;
+
+import { MassetStructs } from "../MassetStructs.sol";
+
+import { SafeCast } from "@openzeppelin/contracts/utils/math/SafeCast.sol";
+
+import { IBasketManager } from "../../z_mocks/masset/migrate3/IBasketManager.sol";
+import { Basket, Basset } from "../../z_mocks/masset/migrate3/MassetStructsV2.sol";
+
+
+library Migrator {
+
+    function upgrade(
+        IBasketManager basketManager,
+        MassetStructs.BassetPersonal[] storage bAssetPersonal,
+        MassetStructs.BassetData[] storage bAssetData,
+        mapping(address => uint8) storage bAssetIndexes
+    ) external {
+        Basket memory importedBasket = basketManager.getBasket();
+
+        uint256 len = importedBasket.bassets.length;
+        uint256[] memory scaledVaultBalances = new uint[](len);
+        uint256 maxScaledVaultBalance;
+        for (uint8 i = 0; i < len; i++) {
+            Basset memory bAsset = importedBasket.bassets[i];
+            address bAssetAddress = bAsset.addr;
+            bAssetIndexes[bAssetAddress] = i;
+
+            address integratorAddress = basketManager.getBassetIntegrator(bAssetAddress);
+            bAssetPersonal.push(
+                MassetStructs.BassetPersonal({
+                    addr: bAssetAddress,
+                    integrator: integratorAddress,
+                    hasTxFee: false,
+                    status: MassetStructs.BassetStatus.Normal
+                })
+            );
+
+            uint128 ratio = SafeCast.toUint128(bAsset.ratio);
+            uint128 vaultBalance = SafeCast.toUint128(bAsset.vaultBalance);
+            bAssetData.push(
+                MassetStructs.BassetData({ ratio: ratio, vaultBalance: vaultBalance })
+            );
+
+            // caclulate scaled vault bAsset balance and totoal vault balance
+            uint128 scaledVaultBalance = (vaultBalance * ratio) / 1e8;
+            scaledVaultBalances[i] = scaledVaultBalance;
+            maxScaledVaultBalance += scaledVaultBalance;
+        }
+
+        // Check each bAsset is under 25.01% weight
+        uint256 maxWeight = 2501;
+        if(len == 3){
+            maxWeight = 3334;
+        } else if (len != 4){
+            revert("Invalid length");
+        }
+        maxScaledVaultBalance = maxScaledVaultBalance * 2501 / 10000;
+        for (uint8 i = 0; i < len; i++) {
+            require(scaledVaultBalances[i] < maxScaledVaultBalance, "imbalanced");
+        }
+    }
+}