Implement open wallet functionality

cw_ethereum/lib/ethereum_balance.dart

@@ -4,7 +4,7 @@ import 'package:cw_core/balance.dart';
 import 'package:web3dart/web3dart.dart';
 
 class EthereumBalance extends Balance {
-  EthereumBalance(super.available, super.additional);
+  EthereumBalance({required int available, required int additional}) : super(available, additional);
 
   @override
   String get formattedAdditionalBalance {
@@ -18,4 +18,17 @@ class EthereumBalance extends Balance {
       EtherAmount.fromUnitAndValue(EtherUnit.ether, available.toString()).getInEther.toString();
 
   String toJSON() => json.encode({'available': available, 'additional': additional});
+
+  static EthereumBalance? fromJSON(String? jsonSource) {
+    if (jsonSource == null) {
+      return null;
+    }
+
+    final decoded = json.decode(jsonSource) as Map;
+
+    return EthereumBalance(
+      available: decoded['available'] as int? ?? 0,
+      additional: decoded['additional'] as int? ?? 0,
+    );
+  }
 }

cw_ethereum/lib/ethereum_wallet.dart

@@ -18,6 +18,9 @@ import 'package:cw_ethereum/ethereum_wallet_addresses.dart';
 import 'package:cw_ethereum/file.dart';
 import 'package:mobx/mobx.dart';
 import 'package:web3dart/web3dart.dart';
+import 'package:ed25519_hd_key/ed25519_hd_key.dart';
+import 'package:bip39/bip39.dart' as bip39;
+import 'package:hex/hex.dart';
 
 part 'ethereum_wallet.g.dart';
 
@@ -28,25 +31,24 @@ abstract class EthereumWalletBase
     with Store {
   EthereumWalletBase({
     required WalletInfo walletInfo,
-    required this.mnemonic,
-    required this.privateKey,
+    required String mnemonic,
     required String password,
     EthereumBalance? initialBalance,
   })  : syncStatus = NotConnectedSyncStatus(),
         _password = password,
+        _mnemonic = mnemonic,
         walletAddresses = EthereumWalletAddresses(walletInfo),
         balance = ObservableMap<CryptoCurrency, EthereumBalance>.of(
-            {CryptoCurrency.eth: initialBalance ?? EthereumBalance(0, 0)}),
+            {CryptoCurrency.eth: initialBalance ?? EthereumBalance(available: 0, additional: 0)}),
         super(walletInfo) {
     this.walletInfo = walletInfo;
-    transactionHistory = EthereumTransactionHistory();
-    walletAddresses.address = EthPrivateKey.fromHex(privateKey).address.toString();
   }
 
-  final String mnemonic;
-  final String privateKey;
+  final String _mnemonic;
   final String _password;
 
+  late final String privateKey;
+
   late EthereumClient _client;
 
   EtherAmount? _gasPrice;
@@ -61,6 +63,12 @@ abstract class EthereumWalletBase
   @observable
   late ObservableMap<CryptoCurrency, EthereumBalance> balance;
 
+  Future<void> init() async {
+    privateKey = await getPrivateKey(_mnemonic, _password);
+    transactionHistory = EthereumTransactionHistory();
+    walletAddresses.address = EthPrivateKey.fromHex(privateKey).address.toString();
+  }
+
   @override
   int calculateEstimatedFee(TransactionPriority priority, int? amount) {
     throw UnimplementedError("calculateEstimatedFee");
@@ -119,7 +127,7 @@ abstract class EthereumWalletBase
   }
 
   @override
-  String get seed => mnemonic;
+  String get seed => _mnemonic;
 
   @override
   Future<void> startSync() async {
@@ -150,11 +158,31 @@ abstract class EthereumWalletBase
   Future<String> makePath() async => pathForWallet(name: walletInfo.name, type: walletInfo.type);
 
   String toJSON() => json.encode({
-        'mnemonic': mnemonic,
+        'mnemonic': _mnemonic,
         'balance': balance[currency]!.toJSON(),
         // TODO: save other attributes
       });
 
+  static Future<EthereumWallet> open({
+    required String name,
+    required String password,
+    required WalletInfo walletInfo,
+  }) async {
+    final path = await pathForWallet(name: name, type: walletInfo.type);
+    final jsonSource = await read(path: path, password: password);
+    final data = json.decode(jsonSource) as Map;
+    final mnemonic = data['mnemonic'] as String;
+    final balance = EthereumBalance.fromJSON(data['balance'] as String) ??
+        EthereumBalance(available: 0, additional: 0);
+
+    return EthereumWallet(
+      walletInfo: walletInfo,
+      password: password,
+      mnemonic: mnemonic,
+      initialBalance: balance,
+    );
+  }
+
   Future<void> _updateBalance() async {
     balance[currency] = await _fetchBalances();
     await save();
@@ -163,6 +191,17 @@ abstract class EthereumWalletBase
   Future<EthereumBalance> _fetchBalances() async {
     final balance = await _client.getBalance(privateKey);
 
-    return EthereumBalance(balance.getInEther.toInt(), balance.getInEther.toInt());
+    return EthereumBalance(
+      available: balance.getInEther.toInt(),
+      additional: balance.getInEther.toInt(),
+    );
+  }
+
+  Future<String> getPrivateKey(String mnemonic, String password) async {
+    final seed = bip39.mnemonicToSeedHex(mnemonic);
+    final master = await ED25519_HD_KEY.getMasterKeyFromSeed(HEX.decode(seed),
+        masterSecret: password);
+    final privateKey = HEX.encode(master.key);
+    return privateKey;
   }
 }

cw_ethereum/lib/ethereum_wallet_service.dart

@@ -10,10 +10,8 @@ import 'package:cw_core/wallet_service.dart';
 import 'package:cw_core/wallet_type.dart';
 import 'package:cw_ethereum/ethereum_wallet.dart';
 import 'package:cw_ethereum/ethereum_wallet_creation_credentials.dart';
-import 'package:ed25519_hd_key/ed25519_hd_key.dart';
 import 'package:hive/hive.dart';
 import 'package:bip39/bip39.dart' as bip39;
-import 'package:hex/hex.dart';
 
 class EthereumWalletService extends WalletService<EthereumNewWalletCredentials,
     EthereumRestoreWalletFromSeedCredentials, EthereumRestoreWalletFromWIFCredentials> {
@@ -24,13 +22,13 @@ class EthereumWalletService extends WalletService<EthereumNewWalletCredentials,
   @override
   Future<EthereumWallet> create(EthereumNewWalletCredentials credentials) async {
     final mnemonic = bip39.generateMnemonic();
-    final privateKey = await getPrivateKey(mnemonic, credentials.password!);
     final wallet = EthereumWallet(
       walletInfo: credentials.walletInfo!,
       mnemonic: mnemonic,
-      privateKey: privateKey,
       password: credentials.password!,
     );
+
+    await wallet.init();
     await wallet.save();
 
     return wallet;
@@ -44,10 +42,19 @@ class EthereumWalletService extends WalletService<EthereumNewWalletCredentials,
       File(await pathForWallet(name: name, type: getType())).existsSync();
 
   @override
-  Future<WalletBase<Balance, TransactionHistoryBase<TransactionInfo>, TransactionInfo>> openWallet(
-      String name, String password) {
-    // TODO: implement openWallet
-    throw UnimplementedError();
+  Future<EthereumWallet> openWallet(String name, String password) async {
+    final walletInfo =
+        walletInfoSource.values.firstWhere((info) => info.id == WalletBase.idFor(name, getType()));
+    final wallet = await EthereumWalletBase.open(
+      name: name,
+      password: password,
+      walletInfo: walletInfo,
+    );
+
+    await wallet.init();
+    await wallet.save();
+
+    return wallet;
   }
 
   @override
@@ -66,12 +73,4 @@ class EthereumWalletService extends WalletService<EthereumNewWalletCredentials,
     // TODO: implement restoreFromSeed
     throw UnimplementedError();
   }
-
-  Future<String> getPrivateKey(String mnemonic, String password) async {
-    final seed = bip39.mnemonicToSeedHex(mnemonic);
-    final master = await ED25519_HD_KEY.getMasterKeyFromSeed(HEX.decode(seed),
-        masterSecret: password);
-    final privateKey = HEX.encode(master.key);
-    return privateKey;
-  }
 }