stack_wallet/lib/wallets/wallet/impl/bitcoin_wallet.dart

import 'package:isar/isar.dart';
import 'package:stackwallet/models/isar/models/blockchain_data/address.dart';
import 'package:stackwallet/models/isar/models/blockchain_data/transaction.dart';
import 'package:stackwallet/models/isar/models/blockchain_data/v2/input_v2.dart';
import 'package:stackwallet/models/isar/models/blockchain_data/v2/output_v2.dart';
import 'package:stackwallet/models/isar/models/blockchain_data/v2/transaction_v2.dart';
import 'package:stackwallet/utilities/amount/amount.dart';
import 'package:stackwallet/utilities/extensions/extensions.dart';
import 'package:stackwallet/utilities/logger.dart';
import 'package:stackwallet/wallets/crypto_currency/coins/bitcoin.dart';
import 'package:stackwallet/wallets/crypto_currency/crypto_currency.dart';
import 'package:stackwallet/wallets/wallet/intermediate/bip39_hd_wallet.dart';
import 'package:stackwallet/wallets/wallet/wallet_mixin_interfaces/coin_control_interface.dart';
import 'package:stackwallet/wallets/wallet/wallet_mixin_interfaces/electrumx_interface.dart';
import 'package:stackwallet/wallets/wallet/wallet_mixin_interfaces/paynym_interface.dart';

class BitcoinWallet extends Bip39HDWallet
    with ElectrumXInterface, CoinControlInterface, PaynymInterface {
  @override
  int get isarTransactionVersion => 2;

  BitcoinWallet(CryptoCurrencyNetwork network) : super(Bitcoin(network));

  @override
  FilterOperation? get changeAddressFilterOperation =>
      FilterGroup.and(standardChangeAddressFilters);

  @override
  FilterOperation? get receivingAddressFilterOperation =>
      FilterGroup.and(standardReceivingAddressFilters);

  // ===========================================================================

  @override
  Future<List<Address>> fetchAddressesForElectrumXScan() async {
    final allAddresses = await mainDB
        .getAddresses(walletId)
        .filter()
        .not()
        .group(
          (q) => q
              .typeEqualTo(AddressType.nonWallet)
              .or()
              .subTypeEqualTo(AddressSubType.nonWallet),
        )
        .findAll();
    return allAddresses;
  }

  // ===========================================================================

  @override
  Future<void> updateTransactions() async {
    // Get all addresses.
    List<Address> allAddressesOld = await fetchAddressesForElectrumXScan();

    // Separate receiving and change addresses.
    Set<String> receivingAddresses = allAddressesOld
        .where((e) => e.subType == AddressSubType.receiving)
        .map((e) => e.value)
        .toSet();
    Set<String> changeAddresses = allAddressesOld
        .where((e) => e.subType == AddressSubType.change)
        .map((e) => e.value)
        .toSet();

    // Remove duplicates.
    final allAddressesSet = {...receivingAddresses, ...changeAddresses};

    // Fetch history from ElectrumX.
    final List<Map<String, dynamic>> allTxHashes =
        await fetchHistory(allAddressesSet);

    // Only parse new txs (not in db yet).
    List<Map<String, dynamic>> allTransactions = [];
    for (final txHash in allTxHashes) {
      // Check for duplicates by searching for tx by tx_hash in db.
      final storedTx = await mainDB.isar.transactionV2s
          .where()
          .txidWalletIdEqualTo(txHash["tx_hash"] as String, walletId)
          .findFirst();

      if (storedTx == null ||
          storedTx.height == null ||
          (storedTx.height != null && storedTx.height! <= 0)) {
        // Tx not in db yet.
        final tx = await electrumXCachedClient.getTransaction(
          txHash: txHash["tx_hash"] as String,
          verbose: true,
          coin: cryptoCurrency.coin,
        );

        // Only tx to list once.
        if (allTransactions
                .indexWhere((e) => e["txid"] == tx["txid"] as String) ==
            -1) {
          tx["height"] = txHash["height"];
          allTransactions.add(tx);
        }
      }
    }

    // Parse all new txs.
    final List<TransactionV2> txns = [];
    for (final txData in allTransactions) {
      bool wasSentFromThisWallet = false;
      // Set to true if any inputs were detected as owned by this wallet.

      bool wasReceivedInThisWallet = false;
      // Set to true if any outputs were detected as owned by this wallet.

      // Parse inputs.
      BigInt amountReceivedInThisWallet = BigInt.zero;
      BigInt changeAmountReceivedInThisWallet = BigInt.zero;
      final List<InputV2> inputs = [];
      for (final jsonInput in txData["vin"] as List) {
        final map = Map<String, dynamic>.from(jsonInput as Map);

        final List<String> addresses = [];
        String valueStringSats = "0";
        OutpointV2? outpoint;

        final coinbase = map["coinbase"] as String?;

        if (coinbase == null) {
          // Not a coinbase (ie a typical input).
          final txid = map["txid"] as String;
          final vout = map["vout"] as int;

          final inputTx = await electrumXCachedClient.getTransaction(
            txHash: txid,
            coin: cryptoCurrency.coin,
          );

          final prevOutJson = Map<String, dynamic>.from(
              (inputTx["vout"] as List).firstWhere((e) => e["n"] == vout)
                  as Map);

          final prevOut = OutputV2.fromElectrumXJson(
            prevOutJson,
            decimalPlaces: cryptoCurrency.fractionDigits,
            isFullAmountNotSats: true,
            walletOwns: false, // Doesn't matter here as this is not saved.
          );

          outpoint = OutpointV2.isarCantDoRequiredInDefaultConstructor(
            txid: txid,
            vout: vout,
          );
          valueStringSats = prevOut.valueStringSats;
          addresses.addAll(prevOut.addresses);
        }

        InputV2 input = InputV2.isarCantDoRequiredInDefaultConstructor(
          scriptSigHex: map["scriptSig"]?["hex"] as String?,
          sequence: map["sequence"] as int?,
          outpoint: outpoint,
          valueStringSats: valueStringSats,
          addresses: addresses,
          witness: map["witness"] as String?,
          coinbase: coinbase,
          innerRedeemScriptAsm: map["innerRedeemscriptAsm"] as String?,
          // Need addresses before we can know if the wallet owns this input.
          walletOwns: false,
        );

        // Check if input was from this wallet.
        if (allAddressesSet.intersection(input.addresses.toSet()).isNotEmpty) {
          wasSentFromThisWallet = true;
          input = input.copyWith(walletOwns: true);
        }

        inputs.add(input);
      }

      // Parse outputs.
      final List<OutputV2> outputs = [];
      for (final outputJson in txData["vout"] as List) {
        OutputV2 output = OutputV2.fromElectrumXJson(
          Map<String, dynamic>.from(outputJson as Map),
          decimalPlaces: cryptoCurrency.fractionDigits,
          isFullAmountNotSats: true,
          // Need addresses before we can know if the wallet owns this input.
          walletOwns: false,
        );

        // If output was to my wallet, add value to amount received.
        if (receivingAddresses
            .intersection(output.addresses.toSet())
            .isNotEmpty) {
          wasReceivedInThisWallet = true;
          amountReceivedInThisWallet += output.value;
          output = output.copyWith(walletOwns: true);
        } else if (changeAddresses
            .intersection(output.addresses.toSet())
            .isNotEmpty) {
          wasReceivedInThisWallet = true;
          changeAmountReceivedInThisWallet += output.value;
          output = output.copyWith(walletOwns: true);
        }

        outputs.add(output);
      }

      final totalOut = outputs
          .map((e) => e.value)
          .fold(BigInt.zero, (value, element) => value + element);

      TransactionType type;
      TransactionSubType subType = TransactionSubType.none;

      // At least one input was owned by this wallet.
      if (wasSentFromThisWallet) {
        type = TransactionType.outgoing;

        if (wasReceivedInThisWallet) {
          if (changeAmountReceivedInThisWallet + amountReceivedInThisWallet ==
              totalOut) {
            // Definitely sent all to self.
            type = TransactionType.sentToSelf;
          } else if (amountReceivedInThisWallet == BigInt.zero) {
            // Most likely just a typical send, do nothing here yet.
          }
        }
      } else if (wasReceivedInThisWallet) {
        // Only found outputs owned by this wallet.
        type = TransactionType.incoming;

        // TODO: [prio=none] Check for special Bitcoin outputs like ordinals.
      } else {
        Logging.instance.log(
          "Unexpected tx found (ignoring it): $txData",
          level: LogLevel.Error,
        );
        continue;
      }

      final tx = TransactionV2(
        walletId: walletId,
        blockHash: txData["blockhash"] as String?,
        hash: txData["hash"] as String,
        txid: txData["txid"] as String,
        height: txData["height"] as int?,
        version: txData["version"] as int,
        timestamp: txData["blocktime"] as int? ??
            DateTime.timestamp().millisecondsSinceEpoch ~/ 1000,
        inputs: List.unmodifiable(inputs),
        outputs: List.unmodifiable(outputs),
        type: type,
        subType: subType,
        otherData: null,
      );

      txns.add(tx);
    }

    await mainDB.updateOrPutTransactionV2s(txns);
  }

  @override
  Future<({String? blockedReason, bool blocked, String? utxoLabel})>
      checkBlockUTXO(
    Map<String, dynamic> jsonUTXO,
    String? scriptPubKeyHex,
    Map<String, dynamic>? jsonTX,
    String? utxoOwnerAddress,
  ) async {
    bool blocked = false;
    String? blockedReason;

    if (jsonTX != null) {
      // check for bip47 notification
      final outputs = jsonTX["vout"] as List;
      for (final output in outputs) {
        List<String>? scriptChunks =
            (output['scriptPubKey']?['asm'] as String?)?.split(" ");
        if (scriptChunks?.length == 2 && scriptChunks?[0] == "OP_RETURN") {
          final blindedPaymentCode = scriptChunks![1];
          final bytes = blindedPaymentCode.toUint8ListFromHex;

          // https://en.bitcoin.it/wiki/BIP_0047#Sending
          if (bytes.length == 80 && bytes.first == 1) {
            blocked = true;
            blockedReason = "Paynym notification output. Incautious "
                "handling of outputs from notification transactions "
                "may cause unintended loss of privacy.";
            break;
          }
        }
      }
    }

    return (blockedReason: blockedReason, blocked: blocked, utxoLabel: null);
  }

  @override
  Amount roughFeeEstimate(int inputCount, int outputCount, int feeRatePerKB) {
    return Amount(
      rawValue: BigInt.from(
          ((42 + (272 * inputCount) + (128 * outputCount)) / 4).ceil() *
              (feeRatePerKB / 1000).ceil()),
      fractionDigits: cryptoCurrency.fractionDigits,
    );
  }

  @override
  int estimateTxFee({required int vSize, required int feeRatePerKB}) {
    return vSize * (feeRatePerKB / 1000).ceil();
  }
  //
  // @override
  // Future<TxData> coinSelection({required TxData txData}) async {
  //   final isCoinControl = txData.utxos != null;
  //   final isSendAll = txData.amount == info.cachedBalance.spendable;
  //
  //   final utxos =
  //       txData.utxos?.toList() ?? await mainDB.getUTXOs(walletId).findAll();
  //
  //   final currentChainHeight = await chainHeight;
  //   final List<UTXO> spendableOutputs = [];
  //   int spendableSatoshiValue = 0;
  //
  //   // Build list of spendable outputs and totaling their satoshi amount
  //   for (final utxo in utxos) {
  //     if (utxo.isBlocked == false &&
  //         utxo.isConfirmed(currentChainHeight, cryptoCurrency.minConfirms) &&
  //         utxo.used != true) {
  //       spendableOutputs.add(utxo);
  //       spendableSatoshiValue += utxo.value;
  //     }
  //   }
  //
  //   if (isCoinControl && spendableOutputs.length < utxos.length) {
  //     throw ArgumentError("Attempted to use an unavailable utxo");
  //   }
  //
  //   if (spendableSatoshiValue < txData.amount!.raw.toInt()) {
  //     throw Exception("Insufficient balance");
  //   } else if (spendableSatoshiValue == txData.amount!.raw.toInt() &&
  //       !isSendAll) {
  //     throw Exception("Insufficient balance to pay transaction fee");
  //   }
  //
  //   if (isCoinControl) {
  //   } else {
  //     final selection = cs.coinSelection(
  //       spendableOutputs
  //           .map((e) => cs.InputModel(
  //                 i: e.vout,
  //                 txid: e.txid,
  //                 value: e.value,
  //                 address: e.address,
  //               ))
  //           .toList(),
  //       txData.recipients!
  //           .map((e) => cs.OutputModel(
  //                 address: e.address,
  //                 value: e.amount.raw.toInt(),
  //               ))
  //           .toList(),
  //       txData.feeRateAmount!,
  //       10, // TODO: ???????????????????????????????
  //     );
  //
  //     // .inputs and .outputs will be null if no solution was found
  //     if (selection.inputs!.isEmpty || selection.outputs!.isEmpty) {
  //       throw Exception("coin selection failed");
  //     }
  //   }
  // }
}