cake_wallet/cw_bitcoin/lib/electrum_wallet.dart
2022-10-12 13:09:57 -04:00

675 lines
21 KiB
Dart

import 'dart:async';
import 'dart:convert';
import 'dart:math';
import 'dart:typed_data';
import 'package:cw_core/unspent_coins_info.dart';
import 'package:hive/hive.dart';
import 'package:cw_bitcoin/electrum_wallet_addresses.dart';
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:cw_bitcoin/electrum_transaction_info.dart';
import 'package:cw_core/pathForWallet.dart';
import 'package:cw_bitcoin/address_to_output_script.dart';
import 'package:cw_bitcoin/bitcoin_address_record.dart';
import 'package:cw_bitcoin/electrum_balance.dart';
import 'package:cw_bitcoin/bitcoin_mnemonic.dart';
import 'package:cw_bitcoin/bitcoin_transaction_credentials.dart';
import 'package:cw_bitcoin/electrum_transaction_history.dart';
import 'package:cw_bitcoin/bitcoin_transaction_no_inputs_exception.dart';
import 'package:cw_bitcoin/bitcoin_transaction_priority.dart';
import 'package:cw_bitcoin/bitcoin_transaction_wrong_balance_exception.dart';
import 'package:cw_bitcoin/bitcoin_unspent.dart';
import 'package:cw_bitcoin/bitcoin_wallet_keys.dart';
import 'package:cw_bitcoin/file.dart';
import 'package:cw_bitcoin/pending_bitcoin_transaction.dart';
import 'package:cw_bitcoin/script_hash.dart';
import 'package:cw_bitcoin/utils.dart';
import 'package:cw_core/wallet_base.dart';
import 'package:cw_core/node.dart';
import 'package:cw_core/sync_status.dart';
import 'package:cw_core/transaction_priority.dart';
import 'package:cw_core/wallet_info.dart';
import 'package:cw_bitcoin/electrum.dart';
import 'package:hex/hex.dart';
import 'package:cw_core/crypto_currency.dart';
import 'package:collection/collection.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 Box<UnspentCoinsInfo> unspentCoinsInfo,
required this.networkType,
required this.mnemonic,
required Uint8List seedBytes,
List<BitcoinAddressRecord>? initialAddresses,
ElectrumClient? electrumClient,
ElectrumBalance? initialBalance,
CryptoCurrency? currency})
: hd = bitcoin.HDWallet.fromSeed(seedBytes, network: networkType)
.derivePath("m/0'/0"),
syncStatus = NotConnectedSyncStatus(),
_password = password,
_feeRates = <int>[],
_isTransactionUpdating = false,
unspentCoins = [],
_scripthashesUpdateSubject = {},
balance = ObservableMap<CryptoCurrency, ElectrumBalance>.of(
currency != null
? {currency: initialBalance ?? const ElectrumBalance(confirmed: 0, unconfirmed: 0)}
: {}),
this.unspentCoinsInfo = unspentCoinsInfo,
super(walletInfo) {
this.electrumClient = electrumClient ?? ElectrumClient();
this.walletInfo = walletInfo;
transactionHistory =
ElectrumTransactionHistory(walletInfo: walletInfo, password: password);
}
static int estimatedTransactionSize(int inputsCount, int outputsCounts) =>
inputsCount * 146 + outputsCounts * 33 + 8;
final bitcoin.HDWallet hd;
final String mnemonic;
late ElectrumClient electrumClient;
Box<UnspentCoinsInfo> unspentCoinsInfo;
@override
late ElectrumWalletAddresses walletAddresses;
@override
@observable
late ObservableMap<CryptoCurrency, ElectrumBalance> balance;
@override
@observable
SyncStatus syncStatus;
List<String> get scriptHashes => walletAddresses.addresses
.map((addr) => scriptHash(addr.address, networkType: networkType))
.toList();
List<String> get publicScriptHashes => walletAddresses.addresses
.where((addr) => !addr.isHidden)
.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!);
String _password;
List<BitcoinUnspent> unspentCoins;
List<int> _feeRates;
Map<String, BehaviorSubject<Object>?> _scripthashesUpdateSubject;
bool _isTransactionUpdating;
Future<void> init() async {
await walletAddresses.init();
await transactionHistory.init();
await save();
}
@action
@override
Future<void> startSync() async {
try {
syncStatus = StartingSyncStatus();
await walletAddresses.discoverAddresses();
await 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, stacktrace) {
print(stacktrace);
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 outputs = transactionCredentials.outputs;
final hasMultiDestination = outputs.length > 1;
var allInputsAmount = 0;
if (unspentCoins.isEmpty) {
await updateUnspent();
}
for (final utx in unspentCoins) {
if (utx.isSending) {
allInputsAmount += utx.value;
inputs.add(utx);
}
}
if (inputs.isEmpty) {
throw BitcoinTransactionNoInputsException();
}
final allAmountFee = feeAmountForPriority(
transactionCredentials.priority!, inputs.length, outputs.length);
final allAmount = allInputsAmount - allAmountFee;
var credentialsAmount = 0;
var amount = 0;
var fee = 0;
if (hasMultiDestination) {
if (outputs.any((item) => item.sendAll
|| item.formattedCryptoAmount! <= 0)) {
throw BitcoinTransactionWrongBalanceException(currency);
}
credentialsAmount = outputs.fold(0, (acc, value) =>
acc + value.formattedCryptoAmount!);
if (allAmount - credentialsAmount < minAmount) {
throw BitcoinTransactionWrongBalanceException(currency);
}
amount = credentialsAmount;
if (transactionCredentials.feeRate != null) {
fee = calculateEstimatedFeeWithFeeRate(transactionCredentials.feeRate!, amount,
outputsCount: outputs.length + 1);
} else {
fee = calculateEstimatedFee(transactionCredentials.priority, amount,
outputsCount: outputs.length + 1);
}
} else {
final output = outputs.first;
credentialsAmount = !output.sendAll
? output.formattedCryptoAmount!
: 0;
if (credentialsAmount > allAmount) {
throw BitcoinTransactionWrongBalanceException(currency);
}
amount = output.sendAll || allAmount - credentialsAmount < minAmount
? allAmount
: credentialsAmount;
if (output.sendAll || amount == allAmount) {
fee = allAmountFee;
} else if (transactionCredentials.feeRate != null) {
fee = calculateEstimatedFeeWithFeeRate(transactionCredentials.feeRate!, amount);
} else {
fee = calculateEstimatedFee(transactionCredentials.priority, amount);
}
}
if (fee == 0) {
throw BitcoinTransactionWrongBalanceException(currency);
}
final totalAmount = amount + fee;
if (totalAmount > balance[currency]!.confirmed || totalAmount > allInputsAmount) {
throw BitcoinTransactionWrongBalanceException(currency);
}
final txb = bitcoin.TransactionBuilder(network: networkType);
final changeAddress = await walletAddresses.getChangeAddress();
var leftAmount = totalAmount;
var totalInputAmount = 0;
inputs.clear();
for (final utx in unspentCoins) {
if (utx.isSending) {
leftAmount = leftAmount - utx.value;
totalInputAmount += utx.value;
inputs.add(utx);
if (leftAmount <= 0) {
break;
}
}
}
if (inputs.isEmpty) {
throw BitcoinTransactionNoInputsException();
}
if (amount <= 0 || totalInputAmount < totalAmount) {
throw BitcoinTransactionWrongBalanceException(currency);
}
txb.setVersion(1);
inputs.forEach((input) {
if (input.isP2wpkh) {
final p2wpkh = bitcoin
.P2WPKH(
data: generatePaymentData(
hd: input.address.isHidden ? walletAddresses.sideHd : walletAddresses.mainHd,
index: input.address.index),
network: networkType)
.data;
txb.addInput(input.hash, input.vout, null, p2wpkh.output);
} else {
txb.addInput(input.hash, input.vout);
}
});
outputs.forEach((item) {
final outputAmount = hasMultiDestination
? item.formattedCryptoAmount
: amount;
final outputAddress = item.isParsedAddress
? item.extractedAddress!
: item.address;
txb.addOutput(
addressToOutputScript(outputAddress, networkType),
outputAmount!);
});
final estimatedSize =
estimatedTransactionSize(inputs.length, outputs.length + 1);
var feeAmount = 0;
if (transactionCredentials.feeRate != null) {
feeAmount = transactionCredentials.feeRate! * estimatedSize;
} else {
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: input.address.isHidden ? walletAddresses.sideHd : walletAddresses.mainHd,
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': walletAddresses.currentReceiveAddressIndex.toString(),
'change_address_index': walletAddresses.currentChangeAddressIndex.toString(),
'addresses': walletAddresses.addresses.map((addr) => addr.toJSON()).toList(),
'balance': balance[currency]?.toJSON()
});
int feeRate(TransactionPriority priority) {
try {
if (priority is BitcoinTransactionPriority) {
return _feeRates[priority.raw];
}
return 0;
} catch(_) {
return 0;
}
}
int feeAmountForPriority(BitcoinTransactionPriority priority, int inputsCount,
int outputsCount) =>
feeRate(priority) * estimatedTransactionSize(inputsCount, outputsCount);
int feeAmountWithFeeRate(int feeRate, int inputsCount,
int outputsCount) =>
feeRate * estimatedTransactionSize(inputsCount, outputsCount);
@override
int calculateEstimatedFee(TransactionPriority? priority, int? amount,
{int? outputsCount}) {
if (priority is BitcoinTransactionPriority) {
return calculateEstimatedFeeWithFeeRate(
feeRate(priority),
amount,
outputsCount: outputsCount);
}
return 0;
}
int calculateEstimatedFeeWithFeeRate(int feeRate, int? amount,
{int? outputsCount}) {
int inputsCount = 0;
if (amount != null) {
int totalValue = 0;
for (final input in unspentCoins) {
if (totalValue >= amount) {
break;
}
if (input.isSending) {
totalValue += input.value;
inputsCount += 1;
}
}
if (totalValue < amount) return 0;
} else {
for (final input in unspentCoins) {
if (input.isSending) {
inputsCount += 1;
}
}
}
// If send all, then we have no change value
final _outputsCount = outputsCount ?? (amount != null ? 2 : 1);
return feeAmountWithFeeRate(
feeRate, inputsCount, _outputsCount);
}
@override
Future<void> save() async {
final path = await makePath();
await write(path: path, password: _password, data: toJSON());
await transactionHistory.save();
}
@override
Future<void> changePassword(String password) async {
_password = password;
await save();
await transactionHistory.changePassword(password);
}
bitcoin.ECPair keyPairFor({required int index}) =>
generateKeyPair(hd: hd, index: index, network: networkType);
@override
Future<void> rescan({required int height}) async => throw UnimplementedError();
@override
Future<void> close() async {
try {
await electrumClient.close();
} catch (_) {}
}
Future<String> makePath() async =>
pathForWallet(name: walletInfo.name, type: walletInfo.type);
Future<void> updateUnspent() async {
final unspent = await Future.wait(walletAddresses
.addresses.map((address) => electrumClient
.getListUnspentWithAddress(address.address, networkType)
.then((unspent) => unspent
.map((unspent) => BitcoinUnspent.fromJSON(address, unspent)))));
unspentCoins = unspent.expand((e) => e).toList();
if (unspentCoinsInfo.isEmpty) {
unspentCoins.forEach((coin) => _addCoinInfo(coin));
return;
}
if (unspentCoins.isNotEmpty) {
unspentCoins.forEach((coin) {
final coinInfoList = unspentCoinsInfo.values.where((element) =>
element.walletId.contains(id) && element.hash.contains(coin.hash));
if (coinInfoList.isNotEmpty) {
final coinInfo = coinInfoList.first;
coin.isFrozen = coinInfo.isFrozen;
coin.isSending = coinInfo.isSending;
coin.note = coinInfo.note;
} else {
_addCoinInfo(coin);
}
});
}
await _refreshUnspentCoinsInfo();
}
Future<void> _addCoinInfo(BitcoinUnspent coin) async {
final newInfo = UnspentCoinsInfo(
walletId: id,
hash: coin.hash,
isFrozen: coin.isFrozen,
isSending: coin.isSending,
note: coin.note
);
await unspentCoinsInfo.add(newInfo);
}
Future<void> _refreshUnspentCoinsInfo() async {
try {
final List<dynamic> keys = <dynamic>[];
final currentWalletUnspentCoins = unspentCoinsInfo.values
.where((element) => element.walletId.contains(id));
if (currentWalletUnspentCoins.isNotEmpty) {
currentWalletUnspentCoins.forEach((element) {
final existUnspentCoins = unspentCoins.where((coin) => element.hash.contains(coin.hash));
if (existUnspentCoins.isEmpty) {
keys.add(element.key);
}
});
}
if (keys.isNotEmpty) {
await unspentCoinsInfo.deleteAll(keys);
}
} catch (e) {
print(e.toString());
}
}
Future<ElectrumTransactionBundle> getTransactionExpanded(
{required String hash, required int height}) async {
final verboseTransaction = await electrumClient.getTransactionRaw(hash: hash);
final transactionHex = verboseTransaction['hex'] as String;
final original = bitcoin.Transaction.fromHex(transactionHex);
final ins = <bitcoin.Transaction>[];
final time = verboseTransaction['time'] as int;
final confirmations = verboseTransaction['confirmations'] as int ?? 0;
for (final vin in original.ins) {
final id = HEX.encode(vin.hash!.reversed.toList());
final txHex = await electrumClient.getTransactionHex(hash: id);
final tx = bitcoin.Transaction.fromHex(txHex);
ins.add(tx);
}
return ElectrumTransactionBundle(
original,
ins: ins,
time: time,
confirmations: confirmations);
}
Future<ElectrumTransactionInfo> fetchTransactionInfo(
{required String hash, required int height}) async {
final tx = await getTransactionExpanded(hash: hash, height: height);
final addresses = walletAddresses.addresses.map((addr) => addr.address).toSet();
return ElectrumTransactionInfo.fromElectrumBundle(
tx,
walletInfo.type,
networkType,
addresses: addresses,
height: height);
}
@override
Future<Map<String, ElectrumTransactionInfo>> fetchTransactions() async {
final addressHashes = <String, BitcoinAddressRecord>{};
final normalizedHistories = <Map<String, dynamic>>[];
walletAddresses.addresses.forEach((addressRecord) {
final sh = scriptHash(addressRecord.address, networkType: networkType);
addressHashes[sh] = addressRecord;
});
final histories =
addressHashes.keys.map((scriptHash) => electrumClient
.getHistory(scriptHash)
.then((history) => {scriptHash: history}));
final historyResults = await Future.wait(histories);
historyResults.forEach((history) {
history.entries.forEach((historyItem) {
if (historyItem.value.isNotEmpty) {
final address = addressHashes[historyItem.key];
address?.setAsUsed();
normalizedHistories.addAll(historyItem.value);
}
});
});
final historiesWithDetails = await Future.wait(
normalizedHistories
.map((transaction) => fetchTransactionInfo(
hash: transaction['tx_hash'] as String,
height: transaction['height'] as int)));
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);
walletAddresses.updateReceiveAddresses();
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 addresses = walletAddresses.addresses.toList();
final balanceFutures = <Future<Map<String, dynamic>>>[];
for (var i = 0; i < addresses.length; i++) {
final addressRecord = addresses[i];
final sh = scriptHash(addressRecord.address, networkType: networkType);
final balanceFuture = electrumClient.getBalance(sh);
balanceFutures.add(balanceFuture);
}
final balances = await Future.wait(balanceFutures);
var totalConfirmed = 0;
var totalUnconfirmed = 0;
for (var i = 0; i < balances.length; i++) {
final addressRecord = addresses[i];
final balance = balances[i];
final confirmed = balance['confirmed'] as int? ?? 0;
final unconfirmed = balance['unconfirmed'] as int? ?? 0;
totalConfirmed += confirmed;
totalUnconfirmed += unconfirmed;
if (confirmed > 0 || unconfirmed > 0) {
addressRecord.setAsUsed();
}
}
return ElectrumBalance(confirmed: totalConfirmed, unconfirmed: totalUnconfirmed);
}
Future<void> _updateBalance() async {
balance[currency] = await _fetchBalances();
await save();
}
String getChangeAddress() {
const minCountOfHiddenAddresses = 5;
final random = Random();
var addresses = walletAddresses.addresses
.where((addr) => addr.isHidden)
.toList();
if (addresses.length < minCountOfHiddenAddresses) {
addresses = walletAddresses.addresses.toList();
}
return addresses[random.nextInt(addresses.length)].address;
}
}