cake_wallet/lib/bitcoin/electrum_wallet.dart

467 lines
14 KiB
Dart

import 'dart:async';
import 'dart:convert';
import 'package:mobx/mobx.dart';
import 'package:rxdart/subjects.dart';
import 'package:flutter/foundation.dart';
import 'package:bitcoin_flutter/bitcoin_flutter.dart' as bitcoin;
import 'package:cake_wallet/bitcoin/electrum_transaction_info.dart';
import 'package:cake_wallet/entities/pathForWallet.dart';
import 'package:cake_wallet/bitcoin/address_to_output_script.dart';
import 'package:cake_wallet/bitcoin/bitcoin_address_record.dart';
import 'package:cake_wallet/bitcoin/bitcoin_amount_format.dart';
import 'package:cake_wallet/bitcoin/electrum_balance.dart';
import 'package:cake_wallet/bitcoin/bitcoin_mnemonic.dart';
import 'package:cake_wallet/bitcoin/bitcoin_transaction_credentials.dart';
import 'package:cake_wallet/bitcoin/electrum_transaction_history.dart';
import 'package:cake_wallet/bitcoin/bitcoin_transaction_no_inputs_exception.dart';
import 'package:cake_wallet/bitcoin/bitcoin_transaction_priority.dart';
import 'package:cake_wallet/bitcoin/bitcoin_transaction_wrong_balance_exception.dart';
import 'package:cake_wallet/bitcoin/bitcoin_unspent.dart';
import 'package:cake_wallet/bitcoin/bitcoin_wallet_keys.dart';
import 'package:cake_wallet/bitcoin/file.dart';
import 'package:cake_wallet/bitcoin/pending_bitcoin_transaction.dart';
import 'package:cake_wallet/bitcoin/script_hash.dart';
import 'package:cake_wallet/bitcoin/utils.dart';
import 'package:cake_wallet/core/wallet_base.dart';
import 'package:cake_wallet/entities/node.dart';
import 'package:cake_wallet/entities/sync_status.dart';
import 'package:cake_wallet/entities/transaction_priority.dart';
import 'package:cake_wallet/entities/wallet_info.dart';
import 'package:cake_wallet/bitcoin/electrum.dart';
part 'electrum_wallet.g.dart';
class ElectrumWallet = ElectrumWalletBase with _$ElectrumWallet;
abstract class ElectrumWalletBase extends WalletBase<ElectrumBalance,
ElectrumTransactionHistory, ElectrumTransactionInfo> with Store {
ElectrumWalletBase(
{@required String password,
@required WalletInfo walletInfo,
@required List<BitcoinAddressRecord> initialAddresses,
@required this.networkType,
@required this.mnemonic,
ElectrumClient electrumClient,
int accountIndex = 0,
ElectrumBalance initialBalance})
: balance = initialBalance ??
const ElectrumBalance(confirmed: 0, unconfirmed: 0),
hd = bitcoin.HDWallet.fromSeed(mnemonicToSeedBytes(mnemonic),
network: networkType)
.derivePath("m/0'/0"),
addresses = ObservableList<BitcoinAddressRecord>.of(
(initialAddresses ?? []).toSet()),
syncStatus = NotConnectedSyncStatus(),
_password = password,
_accountIndex = accountIndex,
_feeRates = <int>[],
_isTransactionUpdating = false,
super(walletInfo) {
this.electrumClient = electrumClient ?? ElectrumClient();
this.walletInfo = walletInfo;
transactionHistory =
ElectrumTransactionHistory(walletInfo: walletInfo, password: password);
_unspent = [];
_scripthashesUpdateSubject = {};
}
static int estimatedTransactionSize(int inputsCount, int outputsCounts) =>
inputsCount * 146 + outputsCounts * 33 + 8;
final bitcoin.HDWallet hd;
final String mnemonic;
ElectrumClient electrumClient;
@override
@observable
String address;
@override
@observable
ElectrumBalance balance;
@override
@observable
SyncStatus syncStatus;
ObservableList<BitcoinAddressRecord> addresses;
List<String> get scriptHashes => addresses
.map((addr) => scriptHash(addr.address, networkType: networkType))
.toList();
String get xpub => hd.base58;
@override
String get seed => mnemonic;
bitcoin.NetworkType networkType;
@override
BitcoinWalletKeys get keys => BitcoinWalletKeys(
wif: hd.wif, privateKey: hd.privKey, publicKey: hd.pubKey);
final String _password;
List<BitcoinUnspent> _unspent;
List<int> _feeRates;
int _accountIndex;
Map<String, BehaviorSubject<Object>> _scripthashesUpdateSubject;
bool _isTransactionUpdating;
Future<void> init() async {
await generateAddresses();
address = addresses[_accountIndex].address;
await transactionHistory.init();
}
@action
Future<void> nextAddress() async {
_accountIndex += 1;
if (_accountIndex >= addresses.length) {
_accountIndex = 0;
}
address = addresses[_accountIndex].address;
await save();
}
Future<void> generateAddresses() async {
if (addresses.length < 33) {
final addressesCount = 33 - addresses.length;
await generateNewAddresses(addressesCount,
startIndex: addresses.length, hd: hd);
}
}
Future<BitcoinAddressRecord> generateNewAddress(
{bool isHidden = false, bitcoin.HDWallet hd}) async {
_accountIndex += 1;
final _hd = hd ?? this.hd;
final address = BitcoinAddressRecord(
getAddress(index: _accountIndex, hd: _hd),
index: _accountIndex,
isHidden: isHidden);
addresses.add(address);
await save();
return address;
}
Future<List<BitcoinAddressRecord>> generateNewAddresses(int count,
{int startIndex = 0, bitcoin.HDWallet hd, bool isHidden = false}) async {
final list = <BitcoinAddressRecord>[];
for (var i = startIndex; i < count + startIndex; i++) {
final address = BitcoinAddressRecord(getAddress(index: i, hd: hd),
index: i, isHidden: isHidden);
list.add(address);
}
addresses.addAll(list);
await save();
return list;
}
Future<void> updateAddress(String address) async {
for (final addr in addresses) {
if (addr.address == address) {
await save();
break;
}
}
}
@action
@override
Future<void> startSync() async {
try {
syncStatus = StartingSyncStatus();
updateTransactions();
_subscribeForUpdates();
await _updateBalance();
await _updateUnspent();
_feeRates = await electrumClient.feeRates();
Timer.periodic(const Duration(minutes: 1),
(timer) async => _feeRates = await electrumClient.feeRates());
syncStatus = SyncedSyncStatus();
} catch (e) {
print(e.toString());
syncStatus = FailedSyncStatus();
}
}
@action
@override
Future<void> connectToNode({@required Node node}) async {
try {
syncStatus = ConnectingSyncStatus();
await electrumClient.connectToUri(node.uri);
electrumClient.onConnectionStatusChange = (bool isConnected) {
if (!isConnected) {
syncStatus = LostConnectionSyncStatus();
}
};
syncStatus = ConnectedSyncStatus();
} catch (e) {
print(e.toString());
syncStatus = FailedSyncStatus();
}
}
@override
Future<PendingBitcoinTransaction> createTransaction(
Object credentials) async {
const minAmount = 546;
final transactionCredentials = credentials as BitcoinTransactionCredentials;
final inputs = <BitcoinUnspent>[];
final allAmountFee =
calculateEstimatedFee(transactionCredentials.priority, null);
final allAmount = balance.confirmed - allAmountFee;
var fee = 0;
final credentialsAmount = transactionCredentials.amount != null
? stringDoubleToBitcoinAmount(transactionCredentials.amount)
: 0;
final amount = transactionCredentials.amount == null ||
allAmount - credentialsAmount < minAmount
? allAmount
: credentialsAmount;
final txb = bitcoin.TransactionBuilder(network: networkType);
final changeAddress = address;
var leftAmount = amount;
var totalInputAmount = 0;
if (_unspent.isEmpty) {
await _updateUnspent();
}
for (final utx in _unspent) {
leftAmount = leftAmount - utx.value;
totalInputAmount += utx.value;
inputs.add(utx);
if (leftAmount <= 0) {
break;
}
}
if (inputs.isEmpty) {
throw BitcoinTransactionNoInputsException();
}
final totalAmount = amount + fee;
fee = transactionCredentials.amount != null
? feeAmountForPriority(transactionCredentials.priority, inputs.length,
amount == allAmount ? 1 : 2)
: allAmountFee;
if (totalAmount > balance.confirmed) {
throw BitcoinTransactionWrongBalanceException();
}
if (amount <= 0 || totalInputAmount < amount) {
throw BitcoinTransactionWrongBalanceException();
}
txb.setVersion(1);
inputs.forEach((input) {
if (input.isP2wpkh) {
final p2wpkh = bitcoin
.P2WPKH(
data: generatePaymentData(hd: hd, index: input.address.index),
network: networkType)
.data;
txb.addInput(input.hash, input.vout, null, p2wpkh.output);
} else {
txb.addInput(input.hash, input.vout);
}
});
txb.addOutput(
addressToOutputScript(transactionCredentials.address, networkType),
amount);
final estimatedSize = estimatedTransactionSize(inputs.length, 2);
final feeAmount = feeRate(transactionCredentials.priority) * estimatedSize;
final changeValue = totalInputAmount - amount - feeAmount;
if (changeValue > minAmount) {
txb.addOutput(changeAddress, changeValue);
}
for (var i = 0; i < inputs.length; i++) {
final input = inputs[i];
final keyPair = generateKeyPair(
hd: hd, index: input.address.index, network: networkType);
final witnessValue = input.isP2wpkh ? input.value : null;
txb.sign(vin: i, keyPair: keyPair, witnessValue: witnessValue);
}
return PendingBitcoinTransaction(txb.build(), type,
electrumClient: electrumClient, amount: amount, fee: fee)
..addListener((transaction) async {
transactionHistory.addOne(transaction);
await _updateBalance();
});
}
String toJSON() => json.encode({
'mnemonic': mnemonic,
'account_index': _accountIndex.toString(),
'addresses': addresses.map((addr) => addr.toJSON()).toList(),
'balance': balance?.toJSON()
});
int feeRate(TransactionPriority priority) {
if (priority is BitcoinTransactionPriority) {
return _feeRates[priority.raw];
}
return 0;
}
int feeAmountForPriority(BitcoinTransactionPriority priority, int inputsCount,
int outputsCount) =>
feeRate(priority) * estimatedTransactionSize(inputsCount, outputsCount);
@override
int calculateEstimatedFee(TransactionPriority priority, int amount) {
if (priority is BitcoinTransactionPriority) {
int inputsCount = 0;
if (amount != null) {
int totalValue = 0;
for (final input in _unspent) {
if (totalValue >= amount) {
break;
}
totalValue += input.value;
inputsCount += 1;
}
} else {
inputsCount = _unspent.length;
}
// If send all, then we have no change value
return feeAmountForPriority(
priority, inputsCount, amount != null ? 2 : 1);
}
return 0;
}
@override
Future<void> save() async {
final path = await makePath();
await write(path: path, password: _password, data: toJSON());
await transactionHistory.save();
}
bitcoin.ECPair keyPairFor({@required int index}) =>
generateKeyPair(hd: hd, index: index, network: networkType);
@override
Future<void> rescan({int height}) async => throw UnimplementedError();
@override
Future<void> close() async {
try {
await electrumClient?.close();
} catch (_) {}
}
String getAddress({@required int index, @required bitcoin.HDWallet hd}) => '';
Future<String> makePath() async =>
pathForWallet(name: walletInfo.name, type: walletInfo.type);
Future<void> _updateUnspent() async {
final unspent = await Future.wait(addresses.map((address) => electrumClient
.getListUnspentWithAddress(address.address, networkType)
.then((unspent) => unspent
.map((unspent) => BitcoinUnspent.fromJSON(address, unspent)))));
_unspent = unspent.expand((e) => e).toList();
}
Future<ElectrumTransactionInfo> fetchTransactionInfo(
{@required String hash, @required int height}) async {
final tx = await electrumClient.getTransactionExpanded(hash: hash);
return ElectrumTransactionInfo.fromElectrumVerbose(tx, walletInfo.type,
height: height, addresses: addresses);
}
@override
Future<Map<String, ElectrumTransactionInfo>> fetchTransactions() async {
final histories =
scriptHashes.map((scriptHash) => electrumClient.getHistory(scriptHash));
final _historiesWithDetails = await Future.wait(histories)
.then((histories) => histories.expand((i) => i).toList())
.then((histories) => histories.map((tx) => fetchTransactionInfo(
hash: tx['tx_hash'] as String, height: tx['height'] as int)));
final historiesWithDetails = await Future.wait(_historiesWithDetails);
return historiesWithDetails.fold<Map<String, ElectrumTransactionInfo>>(
<String, ElectrumTransactionInfo>{}, (acc, tx) {
acc[tx.id] = acc[tx.id]?.updated(tx) ?? tx;
return acc;
});
}
Future<void> updateTransactions() async {
try {
if (_isTransactionUpdating) {
return;
}
_isTransactionUpdating = true;
final transactions = await fetchTransactions();
transactionHistory.addMany(transactions);
await transactionHistory.save();
_isTransactionUpdating = false;
} catch (e) {
print(e);
_isTransactionUpdating = false;
}
}
void _subscribeForUpdates() {
scriptHashes.forEach((sh) async {
await _scripthashesUpdateSubject[sh]?.close();
_scripthashesUpdateSubject[sh] = electrumClient.scripthashUpdate(sh);
_scripthashesUpdateSubject[sh].listen((event) async {
try {
await _updateBalance();
await _updateUnspent();
await updateTransactions();
} catch (e) {
print(e.toString());
}
});
});
}
Future<ElectrumBalance> _fetchBalances() async {
final balances = await Future.wait(
scriptHashes.map((sh) => electrumClient.getBalance(sh)));
final balance = balances.fold(
ElectrumBalance(confirmed: 0, unconfirmed: 0),
(ElectrumBalance acc, val) => ElectrumBalance(
confirmed: (val['confirmed'] as int ?? 0) + (acc.confirmed ?? 0),
unconfirmed:
(val['unconfirmed'] as int ?? 0) + (acc.unconfirmed ?? 0)));
return balance;
}
Future<void> _updateBalance() async {
balance = await _fetchBalances();
await save();
}
}