import 'dart:async'; import 'dart:convert'; import 'dart:io'; import 'dart:typed_data'; import 'package:bitcoin_flutter/bitcoin_flutter.dart'; import 'package:cake_wallet/bitcoin/bitcoin_amount_format.dart'; import 'package:cake_wallet/bitcoin/script_hash.dart'; import 'package:flutter/foundation.dart'; import 'package:rxdart/rxdart.dart'; String jsonrpcparams(List params) { final _params = params?.map((val) => '"${val.toString()}"')?.join(','); return '[$_params]'; } String jsonrpc( {String method, List params, int id, double version = 2.0}) => '{"jsonrpc": "$version", "method": "$method", "id": "$id", "params": ${json.encode(params)}}\n'; class SocketTask { SocketTask({this.completer, this.isSubscription, this.subject}); final Completer completer; final BehaviorSubject subject; final bool isSubscription; } class ElectrumClient { ElectrumClient() : _id = 0, _isConnected = false, _tasks = {}, unterminatedString = ''; static const connectionTimeout = Duration(seconds: 5); static const aliveTimerDuration = Duration(seconds: 2); bool get isConnected => _isConnected; Socket socket; void Function(bool) onConnectionStatusChange; int _id; final Map _tasks; bool _isConnected; Timer _aliveTimer; String unterminatedString; Future connectToUri(Uri uri) async => await connect(host: uri.host, port: uri.port); Future connect({@required String host, @required int port}) async { try { await socket?.close(); } catch (_) {} socket = await SecureSocket.connect(host, port, timeout: connectionTimeout, onBadCertificate: (_) => true); _setIsConnected(true); socket.listen((Uint8List event) { try { final response = json.decode(utf8.decode(event.toList())) as Map; _handleResponse(response); } on FormatException catch (e) { final msg = e.message.toLowerCase(); if (e.source is String) { unterminatedString += e.source as String; } if (msg.contains("not a subtype of type")) { unterminatedString += e.source as String; return; } if (isJSONStringCorrect(unterminatedString)) { final response = json.decode(unterminatedString) as Map; _handleResponse(response); unterminatedString = ''; } } on TypeError catch (e) { if (!e.toString().contains('Map')) { return; } final source = utf8.decode(event.toList()); unterminatedString += source; if (isJSONStringCorrect(unterminatedString)) { final response = json.decode(unterminatedString) as Map; _handleResponse(response); unterminatedString = null; } } catch (e) { print(e.toString()); } }, onError: (Object error) { print(error.toString()); _setIsConnected(false); }, onDone: () { _setIsConnected(false); }); keepAlive(); } void keepAlive() { _aliveTimer?.cancel(); _aliveTimer = Timer.periodic(aliveTimerDuration, (_) async => ping()); } Future ping() async { try { await callWithTimeout(method: 'server.ping'); _setIsConnected(true); } on RequestFailedTimeoutException catch (_) { _setIsConnected(false); } } Future> version() => call(method: 'server.version').then((dynamic result) { if (result is List) { return result.map((dynamic val) => val.toString()).toList(); } return []; }); Future> getBalance(String scriptHash) => call(method: 'blockchain.scripthash.get_balance', params: [scriptHash]) .then((dynamic result) { if (result is Map) { return result; } return {}; }); Future>> getHistory(String scriptHash) => call(method: 'blockchain.scripthash.get_history', params: [scriptHash]) .then((dynamic result) { if (result is List) { return result.map((dynamic val) { if (val is Map) { return val; } return {}; }).toList(); } return []; }); Future>> getListUnspentWithAddress( String address, NetworkType networkType) => call( method: 'blockchain.scripthash.listunspent', params: [scriptHash(address, networkType: networkType)]) .then((dynamic result) { if (result is List) { return result.map((dynamic val) { if (val is Map) { val['address'] = address; return val; } return {}; }).toList(); } return []; }); Future>> getListUnspent(String scriptHash) => call(method: 'blockchain.scripthash.listunspent', params: [scriptHash]) .then((dynamic result) { if (result is List) { return result.map((dynamic val) { if (val is Map) { return val; } return {}; }).toList(); } return []; }); Future>> getMempool(String scriptHash) => call(method: 'blockchain.scripthash.get_mempool', params: [scriptHash]) .then((dynamic result) { if (result is List) { return result.map((dynamic val) { if (val is Map) { return val; } return {}; }).toList(); } return []; }); Future> getTransactionRaw( {@required String hash}) async => call(method: 'blockchain.transaction.get', params: [hash, true]) .then((dynamic result) { if (result is Map) { return result; } return {}; }); Future> getTransactionExpanded( {@required String hash}) async { try { final originalTx = await getTransactionRaw(hash: hash); final vins = originalTx['vin'] as List; for (dynamic vin in vins) { if (vin is Map) { vin['tx'] = await getTransactionRaw(hash: vin['txid'] as String); } } return originalTx; } catch (_) { return {}; } } Future broadcastTransaction( {@required String transactionRaw}) async => call(method: 'blockchain.transaction.broadcast', params: [transactionRaw]) .then((dynamic result) { if (result is String) { return result; } return ''; }); Future> getMerkle( {@required String hash, @required int height}) async => await call( method: 'blockchain.transaction.get_merkle', params: [hash, height]) as Map; Future> getHeader({@required int height}) async => await call(method: 'blockchain.block.get_header', params: [height]) as Map; Future estimatefee({@required int p}) => call(method: 'blockchain.estimatefee', params: [p]) .then((dynamic result) { if (result is double) { return result; } if (result is String) { return double.parse(result); } return 0; }); Future>> feeHistogram() => call(method: 'mempool.get_fee_histogram').then((dynamic result) { if (result is List) { return result.map((dynamic e) { if (e is List) { return e.map((dynamic ee) => ee is int ? ee : null).toList(); } return null; }).toList(); } return []; }); Future> feeRates() async { try { final topDoubleString = await estimatefee(p: 1); final middleDoubleString = await estimatefee(p: 20); final bottomDoubleString = await estimatefee(p: 100); final top = (stringDoubleToBitcoinAmount(topDoubleString.toString()) / 1000) .round(); final middle = (stringDoubleToBitcoinAmount(middleDoubleString.toString()) / 1000) .round(); final bottom = (stringDoubleToBitcoinAmount(bottomDoubleString.toString()) / 1000) .round(); return [bottom, middle, top]; } catch (_) { return []; } } BehaviorSubject scripthashUpdate(String scripthash) { _id += 1; return subscribe( id: 'blockchain.scripthash.subscribe:$scripthash', method: 'blockchain.scripthash.subscribe', params: [scripthash]); } BehaviorSubject subscribe( {@required String id, @required String method, List params = const []}) { final subscription = BehaviorSubject(); _regisrySubscription(id, subscription); socket.write(jsonrpc(method: method, id: _id, params: params)); return subscription; } Future call({String method, List params = const []}) async { final completer = Completer(); _id += 1; final id = _id; _registryTask(id, completer); socket.write(jsonrpc(method: method, id: id, params: params)); return completer.future; } Future callWithTimeout( {String method, List params = const [], int timeout = 2000}) async { final completer = Completer(); _id += 1; final id = _id; _registryTask(id, completer); socket.write(jsonrpc(method: method, id: id, params: params)); Timer(Duration(milliseconds: timeout), () { if (!completer.isCompleted) { completer.completeError(RequestFailedTimeoutException(method, id)); } }); return completer.future; } Future close() async { _aliveTimer.cancel(); await socket.close(); onConnectionStatusChange = null; } void _registryTask(int id, Completer completer) => _tasks[id.toString()] = SocketTask(completer: completer, isSubscription: false); void _regisrySubscription(String id, BehaviorSubject subject) => _tasks[id] = SocketTask(subject: subject, isSubscription: true); void _finish(String id, Object data) { if (_tasks[id] == null) { return; } if (!(_tasks[id]?.completer?.isCompleted ?? false)) { _tasks[id]?.completer?.complete(data); } if (!(_tasks[id]?.isSubscription ?? false)) { _tasks[id] = null; } else { _tasks[id].subject.add(data); } } void _methodHandler( {@required String method, @required Map request}) { switch (method) { case 'blockchain.scripthash.subscribe': final params = request['params'] as List; final scripthash = params.first as String; final id = 'blockchain.scripthash.subscribe:$scripthash'; _tasks[id]?.subject?.add(params.last); break; default: break; } } void _setIsConnected(bool isConnected) { if (_isConnected != isConnected) { onConnectionStatusChange?.call(isConnected); } _isConnected = isConnected; } void _handleResponse(Map response) { final method = response['method']; final id = response['id'] as String; final result = response['result']; if (method is String) { _methodHandler(method: method, request: response); return; } _finish(id, result); } } // FIXME: move me bool isJSONStringCorrect(String source) { try { json.decode(source); return true; } catch (_) { return false; } } class RequestFailedTimeoutException implements Exception { RequestFailedTimeoutException(this.method, this.id); final String method; final int id; }