import 'dart:async'; import 'package:bip39/bip39.dart' as bip39; import 'package:decimal/decimal.dart'; import 'package:ethereum_addresses/ethereum_addresses.dart'; import 'package:http/http.dart'; import 'package:isar/isar.dart'; import 'package:stackwallet/db/isar/main_db.dart'; import 'package:stackwallet/models/balance.dart'; import 'package:stackwallet/models/isar/models/isar_models.dart'; import 'package:stackwallet/models/node_model.dart'; import 'package:stackwallet/models/paymint/fee_object_model.dart'; import 'package:stackwallet/services/coins/coin_service.dart'; import 'package:stackwallet/services/ethereum/ethereum_api.dart'; import 'package:stackwallet/services/event_bus/events/global/node_connection_status_changed_event.dart'; import 'package:stackwallet/services/event_bus/events/global/refresh_percent_changed_event.dart'; import 'package:stackwallet/services/event_bus/events/global/updated_in_background_event.dart'; import 'package:stackwallet/services/event_bus/events/global/wallet_sync_status_changed_event.dart'; import 'package:stackwallet/services/event_bus/global_event_bus.dart'; import 'package:stackwallet/services/mixins/wallet_cache.dart'; import 'package:stackwallet/services/mixins/wallet_db.dart'; import 'package:stackwallet/services/node_service.dart'; import 'package:stackwallet/services/notifications_api.dart'; import 'package:stackwallet/services/transaction_notification_tracker.dart'; import 'package:stackwallet/utilities/amount.dart'; import 'package:stackwallet/utilities/assets.dart'; import 'package:stackwallet/utilities/constants.dart'; import 'package:stackwallet/utilities/default_nodes.dart'; import 'package:stackwallet/utilities/enums/coin_enum.dart'; import 'package:stackwallet/utilities/enums/fee_rate_type_enum.dart'; import 'package:stackwallet/utilities/eth_commons.dart'; import 'package:stackwallet/utilities/flutter_secure_storage_interface.dart'; import 'package:stackwallet/utilities/format.dart'; import 'package:stackwallet/utilities/logger.dart'; import 'package:stackwallet/utilities/prefs.dart'; import 'package:tuple/tuple.dart'; import 'package:web3dart/web3dart.dart' as web3; const int MINIMUM_CONFIRMATIONS = 3; class EthereumWallet extends CoinServiceAPI with WalletCache, WalletDB { EthereumWallet({ required String walletId, required String walletName, required Coin coin, required SecureStorageInterface secureStore, required TransactionNotificationTracker tracker, MainDB? mockableOverride, }) { txTracker = tracker; _walletId = walletId; _walletName = walletName; _coin = coin; _secureStore = secureStore; initCache(walletId, coin); initWalletDB(mockableOverride: mockableOverride); } NodeModel? _ethNode; final _gasLimit = 21000; Timer? timer; Timer? _networkAliveTimer; Future updateTokenContracts(List contractAddresses) async { // final set = getWalletTokenContractAddresses().toSet(); // set.addAll(contractAddresses); await updateWalletTokenContractAddresses(contractAddresses); GlobalEventBus.instance.fire( UpdatedInBackgroundEvent( "$contractAddresses updated/added for: $walletId $walletName", walletId, ), ); } // Future removeTokenContract(String contractAddress) async { // final set = getWalletTokenContractAddresses().toSet(); // set.removeWhere((e) => e == contractAddress); // await updateWalletTokenContractAddresses(set.toList()); // // GlobalEventBus.instance.fire( // UpdatedInBackgroundEvent( // "$contractAddress removed for: $walletId $walletName", // walletId, // ), // ); // } @override String get walletId => _walletId; late String _walletId; @override String get walletName => _walletName; late String _walletName; @override set walletName(String newName) => _walletName = newName; @override set isFavorite(bool markFavorite) { _isFavorite = markFavorite; updateCachedIsFavorite(markFavorite); } @override bool get isFavorite => _isFavorite ??= getCachedIsFavorite(); bool? _isFavorite; @override Coin get coin => _coin; late Coin _coin; late SecureStorageInterface _secureStore; late final TransactionNotificationTracker txTracker; final _prefs = Prefs.instance; bool longMutex = false; NodeModel getCurrentNode() { return _ethNode ?? NodeService(secureStorageInterface: _secureStore) .getPrimaryNodeFor(coin: coin) ?? DefaultNodes.getNodeFor(coin); } web3.Web3Client getEthClient() { final node = getCurrentNode(); return web3.Web3Client(node.host, Client()); } late web3.EthPrivateKey _credentials; bool _shouldAutoSync = false; @override bool get shouldAutoSync => _shouldAutoSync; @override set shouldAutoSync(bool shouldAutoSync) { if (_shouldAutoSync != shouldAutoSync) { _shouldAutoSync = shouldAutoSync; if (!shouldAutoSync) { timer?.cancel(); timer = null; stopNetworkAlivePinging(); } else { startNetworkAlivePinging(); refresh(); } } } @override Future> get utxos => db.getUTXOs(walletId).findAll(); @override Future> get transactions => db .getTransactions(walletId) .filter() .otherDataEqualTo(null) .sortByTimestampDesc() .findAll(); @override Future get currentReceivingAddress async { final address = await _currentReceivingAddress; return checksumEthereumAddress( address?.value ?? _credentials.address.toString()); } Future get _currentReceivingAddress => db .getAddresses(walletId) .filter() .typeEqualTo(AddressType.ethereum) .subTypeEqualTo(AddressSubType.receiving) .sortByDerivationIndexDesc() .findFirst(); @override Balance get balance => _balance ??= getCachedBalance(); Balance? _balance; Future updateBalance() async { web3.Web3Client client = getEthClient(); web3.EtherAmount ethBalance = await client.getBalance(_credentials.address); // TODO: check if toInt() is ok and if getBalance actually returns enough balance data _balance = Balance( coin: coin, total: ethBalance.getInWei.toInt(), spendable: ethBalance.getInWei.toInt(), blockedTotal: 0, pendingSpendable: 0, ); await updateCachedBalance(_balance!); } @override Future confirmSend({required Map txData}) async { web3.Web3Client client = getEthClient(); final chainId = await client.getChainId(); final amount = txData['recipientAmt'] as int; final decimalAmount = Format.satoshisToAmount(amount, coin: coin); final bigIntAmount = amountToBigInt( decimalAmount.toDouble(), Constants.decimalPlacesForCoin(coin), ); final tx = web3.Transaction( to: web3.EthereumAddress.fromHex(txData['address'] as String), gasPrice: web3.EtherAmount.fromUnitAndValue( web3.EtherUnit.wei, txData['feeInWei']), maxGas: _gasLimit, value: web3.EtherAmount.inWei(bigIntAmount)); final transaction = await client.sendTransaction(_credentials, tx, chainId: chainId.toInt()); return transaction; } @override Future estimateFeeFor(int satoshiAmount, int feeRate) async { final fee = estimateFee(feeRate, _gasLimit, 18); return Format.decimalAmountToSatoshis(Decimal.parse(fee.toString()), coin); } @override Future exit() async { _hasCalledExit = true; timer?.cancel(); timer = null; stopNetworkAlivePinging(); } @override Future get fees => _feeObject ??= _getFees(); Future? _feeObject; Future _getFees() => EthereumAPI.getFees(); //Full rescan is not needed for ETH since we have a balance @override Future fullRescan( int maxUnusedAddressGap, int maxNumberOfIndexesToCheck) { // TODO: implement fullRescan throw UnimplementedError(); } @override Future generateNewAddress() { // TODO: implement generateNewAddress - might not be needed for ETH throw UnimplementedError(); } bool _hasCalledExit = false; @override bool get hasCalledExit => _hasCalledExit; @override Future initializeExisting() async { Logging.instance.log( "initializeExisting() ${coin.prettyName} wallet", level: LogLevel.Info, ); //First get mnemonic so we can initialize credentials String privateKey = getPrivateKey((await mnemonicString)!, (await mnemonicPassphrase)!); _credentials = web3.EthPrivateKey.fromHex(privateKey); if (getCachedId() == null) { throw Exception( "Attempted to initialize an existing wallet using an unknown wallet ID!"); } await _prefs.init(); } @override Future initializeNew() async { Logging.instance.log( "Generating new ${coin.prettyName} wallet.", level: LogLevel.Info, ); if (getCachedId() != null) { throw Exception( "Attempted to initialize a new wallet using an existing wallet ID!"); } await _prefs.init(); try { await _generateNewWallet(); } catch (e, s) { Logging.instance.log( "Exception rethrown from initializeNew(): $e\n$s", level: LogLevel.Fatal, ); rethrow; } await Future.wait([ updateCachedId(walletId), updateCachedIsFavorite(false), ]); } Future _generateNewWallet() async { // Logging.instance // .log("IS_INTEGRATION_TEST: $integrationTestFlag", level: LogLevel.Info); // if (!integrationTestFlag) { // try { // final features = await electrumXClient.getServerFeatures(); // Logging.instance.log("features: $features", level: LogLevel.Info); // switch (coin) { // case Coin.namecoin: // if (features['genesis_hash'] != GENESIS_HASH_MAINNET) { // throw Exception("genesis hash does not match main net!"); // } // break; // default: // throw Exception( // "Attempted to generate a EthereumWallet using a non eth coin type: ${coin.name}"); // } // } catch (e, s) { // Logging.instance.log("$e/n$s", level: LogLevel.Info); // } // } // this should never fail - sanity check if ((await mnemonicString) != null || (await mnemonicPassphrase) != null) { throw Exception( "Attempted to overwrite mnemonic on generate new wallet!"); } final String mnemonic = bip39.generateMnemonic(strength: 256); await _secureStore.write(key: '${_walletId}_mnemonic', value: mnemonic); await _secureStore.write( key: '${_walletId}_mnemonicPassphrase', value: "", ); String privateKey = getPrivateKey(mnemonic, ""); _credentials = web3.EthPrivateKey.fromHex(privateKey); final address = Address( walletId: walletId, value: _credentials.address.toString(), publicKey: [], // maybe store address bytes here? seems a waste of space though derivationIndex: 0, derivationPath: DerivationPath()..value = "$hdPathEthereum/0", type: AddressType.ethereum, subType: AddressSubType.receiving, ); await db.putAddress(address); Logging.instance.log("_generateNewWalletFinished", level: LogLevel.Info); } bool _isConnected = false; @override bool get isConnected => _isConnected; @override bool get isRefreshing => refreshMutex; bool refreshMutex = false; @override Future get maxFee async { final fee = (await fees).fast; final feeEstimate = await estimateFeeFor(0, fee); return feeEstimate; } @override Future> get mnemonic => _getMnemonicList(); @override Future get mnemonicString => _secureStore.read(key: '${_walletId}_mnemonic'); @override Future get mnemonicPassphrase => _secureStore.read( key: '${_walletId}_mnemonicPassphrase', ); Future get chainHeight async { web3.Web3Client client = getEthClient(); try { final height = await client.getBlockNumber(); await updateCachedChainHeight(height); if (height > storedChainHeight) { GlobalEventBus.instance.fire( UpdatedInBackgroundEvent( "Updated current chain height in $walletId $walletName!", walletId, ), ); } return height; } catch (e, s) { Logging.instance.log("Exception caught in chainHeight: $e\n$s", level: LogLevel.Error); return storedChainHeight; } } @override int get storedChainHeight => getCachedChainHeight(); Future> _getMnemonicList() async { final _mnemonicString = await mnemonicString; if (_mnemonicString == null) { return []; } final List data = _mnemonicString.split(' '); return data; } @override Future> prepareSend( {required String address, required int satoshiAmount, Map? args}) async { final feeRateType = args?["feeRate"]; int fee = 0; final feeObject = await fees; switch (feeRateType) { case FeeRateType.fast: fee = feeObject.fast; break; case FeeRateType.average: fee = feeObject.medium; break; case FeeRateType.slow: fee = feeObject.slow; break; } final feeEstimate = await estimateFeeFor(satoshiAmount, fee); bool isSendAll = false; final availableBalance = balance.spendable; if (satoshiAmount == availableBalance) { isSendAll = true; } if (isSendAll) { //Subtract fee amount from send amount satoshiAmount -= feeEstimate; } Map txData = { "fee": feeEstimate, "feeInWei": fee, "address": address, "recipientAmt": satoshiAmount, }; return txData; } @override Future recoverFromMnemonic({ required String mnemonic, String? mnemonicPassphrase, required int maxUnusedAddressGap, required int maxNumberOfIndexesToCheck, required int height, }) async { longMutex = true; final start = DateTime.now(); try { // check to make sure we aren't overwriting a mnemonic // this should never fail if ((await mnemonicString) != null || (await this.mnemonicPassphrase) != null) { longMutex = false; throw Exception("Attempted to overwrite mnemonic on restore!"); } await _secureStore.write( key: '${_walletId}_mnemonic', value: mnemonic.trim()); await _secureStore.write( key: '${_walletId}_mnemonicPassphrase', value: mnemonicPassphrase ?? "", ); String privateKey = getPrivateKey(mnemonic.trim(), mnemonicPassphrase ?? ""); _credentials = web3.EthPrivateKey.fromHex(privateKey); final address = Address( walletId: walletId, value: _credentials.address.toString(), publicKey: [], // maybe store address bytes here? seems a waste of space though derivationIndex: 0, derivationPath: DerivationPath()..value = "$hdPathEthereum/0", type: AddressType.ethereum, subType: AddressSubType.receiving, ); await db.putAddress(address); await Future.wait([ updateCachedId(walletId), updateCachedIsFavorite(false), ]); } catch (e, s) { Logging.instance.log( "Exception rethrown from recoverFromMnemonic(): $e\n$s", level: LogLevel.Error); longMutex = false; rethrow; } longMutex = false; final end = DateTime.now(); Logging.instance.log( "$walletName recovery time: ${end.difference(start).inMilliseconds} millis", level: LogLevel.Info); } Future> _fetchAllOwnAddresses() => db .getAddresses(walletId) .filter() .not() .typeEqualTo(AddressType.nonWallet) .and() .group((q) => q .subTypeEqualTo(AddressSubType.receiving) .or() .subTypeEqualTo(AddressSubType.change)) .findAll(); Future refreshIfThereIsNewData() async { web3.Web3Client client = getEthClient(); if (longMutex) return false; if (_hasCalledExit) return false; final currentChainHeight = await chainHeight; try { bool needsRefresh = false; Set txnsToCheck = {}; for (final String txid in txTracker.pendings) { if (!txTracker.wasNotifiedConfirmed(txid)) { txnsToCheck.add(txid); } } for (String txid in txnsToCheck) { final txn = await client.getTransactionByHash(txid); final int txBlockNumber = txn.blockNumber.blockNum; final int txConfirmations = currentChainHeight - txBlockNumber; bool isUnconfirmed = txConfirmations < MINIMUM_CONFIRMATIONS; if (!isUnconfirmed) { needsRefresh = true; break; } } if (!needsRefresh) { var allOwnAddresses = await _fetchAllOwnAddresses(); final response = await EthereumAPI.getEthTransactions( allOwnAddresses.elementAt(0).value, ); if (response.value != null) { final allTxs = response.value!; for (final element in allTxs) { final txid = element.hash; if ((await db .getTransactions(walletId) .filter() .txidMatches(txid) .findFirst()) == null) { Logging.instance.log( " txid not found in address history already $txid", level: LogLevel.Info); needsRefresh = true; break; } } } else { Logging.instance.log( " refreshIfThereIsNewData get eth transactions failed: ${response.exception}", level: LogLevel.Error, ); } } return needsRefresh; } catch (e, s) { Logging.instance.log( "Exception caught in refreshIfThereIsNewData: $e\n$s", level: LogLevel.Error); rethrow; } } Future getAllTxsToWatch() async { if (_hasCalledExit) return; List unconfirmedTxnsToNotifyPending = []; List unconfirmedTxnsToNotifyConfirmed = []; final currentChainHeight = await chainHeight; final txCount = await db.getTransactions(walletId).count(); const paginateLimit = 50; for (int i = 0; i < txCount; i += paginateLimit) { final transactions = await db .getTransactions(walletId) .offset(i) .limit(paginateLimit) .findAll(); for (final tx in transactions) { if (tx.isConfirmed(currentChainHeight, MINIMUM_CONFIRMATIONS)) { // get all transactions that were notified as pending but not as confirmed if (txTracker.wasNotifiedPending(tx.txid) && !txTracker.wasNotifiedConfirmed(tx.txid)) { unconfirmedTxnsToNotifyConfirmed.add(tx); } } else { // get all transactions that were not notified as pending yet if (!txTracker.wasNotifiedPending(tx.txid)) { unconfirmedTxnsToNotifyPending.add(tx); } } } } // notify on unconfirmed transactions for (final tx in unconfirmedTxnsToNotifyPending) { final confirmations = tx.getConfirmations(currentChainHeight); if (tx.type == TransactionType.incoming) { unawaited(NotificationApi.showNotification( title: "Incoming transaction", body: walletName, walletId: walletId, iconAssetName: Assets.svg.iconFor(coin: coin), date: DateTime.fromMillisecondsSinceEpoch(tx.timestamp * 1000), shouldWatchForUpdates: confirmations < MINIMUM_CONFIRMATIONS, coinName: coin.name, txid: tx.txid, confirmations: confirmations, requiredConfirmations: MINIMUM_CONFIRMATIONS, )); await txTracker.addNotifiedPending(tx.txid); } else if (tx.type == TransactionType.outgoing) { unawaited(NotificationApi.showNotification( title: "Sending transaction", body: walletName, walletId: walletId, iconAssetName: Assets.svg.iconFor(coin: coin), date: DateTime.fromMillisecondsSinceEpoch(tx.timestamp * 1000), shouldWatchForUpdates: confirmations < MINIMUM_CONFIRMATIONS, coinName: coin.name, txid: tx.txid, confirmations: confirmations, requiredConfirmations: MINIMUM_CONFIRMATIONS, )); await txTracker.addNotifiedPending(tx.txid); } } // notify on confirmed for (final tx in unconfirmedTxnsToNotifyConfirmed) { if (tx.type == TransactionType.incoming) { unawaited(NotificationApi.showNotification( title: "Incoming transaction confirmed", body: walletName, walletId: walletId, iconAssetName: Assets.svg.iconFor(coin: coin), date: DateTime.fromMillisecondsSinceEpoch(tx.timestamp * 1000), shouldWatchForUpdates: false, coinName: coin.name, )); await txTracker.addNotifiedConfirmed(tx.txid); } else if (tx.type == TransactionType.outgoing) { unawaited(NotificationApi.showNotification( title: "Outgoing transaction confirmed", body: walletName, walletId: walletId, iconAssetName: Assets.svg.iconFor(coin: coin), date: DateTime.fromMillisecondsSinceEpoch(tx.timestamp * 1000), shouldWatchForUpdates: false, coinName: coin.name, )); await txTracker.addNotifiedConfirmed(tx.txid); } } } @override Future refresh() async { if (refreshMutex) { Logging.instance.log("$walletId $walletName refreshMutex denied", level: LogLevel.Info); return; } else { refreshMutex = true; } try { GlobalEventBus.instance.fire( WalletSyncStatusChangedEvent( WalletSyncStatus.syncing, walletId, coin, ), ); GlobalEventBus.instance.fire(RefreshPercentChangedEvent(0.0, walletId)); GlobalEventBus.instance.fire(RefreshPercentChangedEvent(0.1, walletId)); final currentHeight = await chainHeight; const storedHeight = 1; //await storedChainHeight; Logging.instance .log("chain height: $currentHeight", level: LogLevel.Info); Logging.instance .log("cached height: $storedHeight", level: LogLevel.Info); if (currentHeight != storedHeight) { GlobalEventBus.instance.fire(RefreshPercentChangedEvent(0.2, walletId)); final newTxDataFuture = _refreshTransactions(); GlobalEventBus.instance .fire(RefreshPercentChangedEvent(0.50, walletId)); final feeObj = _getFees(); GlobalEventBus.instance .fire(RefreshPercentChangedEvent(0.60, walletId)); GlobalEventBus.instance .fire(RefreshPercentChangedEvent(0.70, walletId)); _feeObject = Future(() => feeObj); GlobalEventBus.instance .fire(RefreshPercentChangedEvent(0.80, walletId)); final allTxsToWatch = getAllTxsToWatch(); await Future.wait([ updateBalance(), newTxDataFuture, feeObj, allTxsToWatch, ]); GlobalEventBus.instance .fire(RefreshPercentChangedEvent(0.90, walletId)); } refreshMutex = false; GlobalEventBus.instance.fire(RefreshPercentChangedEvent(1.0, walletId)); GlobalEventBus.instance.fire( WalletSyncStatusChangedEvent( WalletSyncStatus.synced, walletId, coin, ), ); if (shouldAutoSync) { timer ??= Timer.periodic(const Duration(seconds: 30), (timer) async { Logging.instance.log( "Periodic refresh check for $walletId $walletName in object instance: $hashCode", level: LogLevel.Info); if (await refreshIfThereIsNewData()) { await refresh(); GlobalEventBus.instance.fire(UpdatedInBackgroundEvent( "New data found in $walletId $walletName in background!", walletId)); } }); } } catch (error, strace) { refreshMutex = false; GlobalEventBus.instance.fire( NodeConnectionStatusChangedEvent( NodeConnectionStatus.disconnected, walletId, coin, ), ); GlobalEventBus.instance.fire( WalletSyncStatusChangedEvent( WalletSyncStatus.unableToSync, walletId, coin, ), ); Logging.instance.log( "Caught exception in $walletName $walletId refresh(): $error\n$strace", level: LogLevel.Warning, ); } } @override Future testNetworkConnection() async { web3.Web3Client client = getEthClient(); try { await client.getBlockNumber(); return true; } catch (_) { return false; } } void _periodicPingCheck() async { bool hasNetwork = await testNetworkConnection(); _isConnected = hasNetwork; if (_isConnected != hasNetwork) { NodeConnectionStatus status = hasNetwork ? NodeConnectionStatus.connected : NodeConnectionStatus.disconnected; GlobalEventBus.instance .fire(NodeConnectionStatusChangedEvent(status, walletId, coin)); } } @override Future updateNode(bool shouldRefresh) async { _ethNode = NodeService(secureStorageInterface: _secureStore) .getPrimaryNodeFor(coin: coin) ?? DefaultNodes.getNodeFor(coin); if (shouldRefresh) { unawaited(refresh()); } } @override Future updateSentCachedTxData(Map txData) async { //Only used for Electrumx coins } @override bool validateAddress(String address) { return isValidEthereumAddress(address); } Future _refreshTransactions() async { String thisAddress = await currentReceivingAddress; final txsResponse = await EthereumAPI.getEthTransactions(thisAddress); if (txsResponse.value != null) { final allTxs = txsResponse.value!; final List> txnsData = []; for (final element in allTxs) { Amount transactionAmount = element.value; bool isIncoming; bool txFailed = false; if (checksumEthereumAddress(element.from) == thisAddress) { if (element.isError != 0) { txFailed = true; } isIncoming = false; } else { isIncoming = true; } //Calculate fees (GasLimit * gasPrice) // int txFee = element.gasPrice * element.gasUsed; Amount txFee = element.gasCost; final String addressString = checksumEthereumAddress(element.to); final int height = element.blockNumber; final txn = Transaction( walletId: walletId, txid: element.hash, timestamp: element.timestamp, type: isIncoming ? TransactionType.incoming : TransactionType.outgoing, subType: TransactionSubType.none, amount: transactionAmount.raw.toInt(), amountString: transactionAmount.toJsonString(), fee: txFee.raw.toInt(), height: height, isCancelled: txFailed, isLelantus: false, slateId: null, otherData: null, inputs: [], outputs: [], ); Address? transactionAddress = await db .getAddresses(walletId) .filter() .valueEqualTo(addressString) .findFirst(); if (transactionAddress == null) { if (isIncoming) { transactionAddress = Address( walletId: walletId, value: addressString, publicKey: [], derivationIndex: 0, derivationPath: DerivationPath()..value = "$hdPathEthereum/0", type: AddressType.ethereum, subType: AddressSubType.receiving, ); } else { final myRcvAddr = await currentReceivingAddress; final isSentToSelf = myRcvAddr == addressString; transactionAddress = Address( walletId: walletId, value: addressString, publicKey: [], derivationIndex: isSentToSelf ? 0 : -1, derivationPath: isSentToSelf ? (DerivationPath()..value = "$hdPathEthereum/0") : null, type: AddressType.ethereum, subType: isSentToSelf ? AddressSubType.receiving : AddressSubType.nonWallet, ); } } txnsData.add(Tuple2(txn, transactionAddress)); } await db.addNewTransactionData(txnsData, walletId); // quick hack to notify manager to call notifyListeners if // transactions changed if (txnsData.isNotEmpty) { GlobalEventBus.instance.fire( UpdatedInBackgroundEvent( "Transactions updated/added for: $walletId $walletName ", walletId, ), ); } } else { Logging.instance.log( "Failed to refresh transactions for ${coin.prettyName} $walletName $walletId", level: LogLevel.Warning, ); } } void stopNetworkAlivePinging() { _networkAliveTimer?.cancel(); _networkAliveTimer = null; } void startNetworkAlivePinging() { // call once on start right away _periodicPingCheck(); // then periodically check _networkAliveTimer = Timer.periodic( Constants.networkAliveTimerDuration, (_) async { _periodicPingCheck(); }, ); } }