detect paynym notification transactions

lib/services/coins/coin_paynym_extension.dart

@@ -28,7 +28,7 @@ extension PayNym on DogecoinWallet {
     return root;
   }
 
-  // fetch or generate this wallet's bip47 payment code
+  /// fetch or generate this wallet's bip47 payment code
   Future<PaymentCode> getPaymentCode() async {
     final address = await db
         .getAddresses(walletId)
@@ -75,7 +75,7 @@ extension PayNym on DogecoinWallet {
   }
 
   void preparePaymentCodeSend(PaymentCode pCode) async {
-    if (!hasConnected(pCode.notificationAddress())) {
+    if (!(await hasConnected(pCode.notificationAddress()))) {
       throw PaynymSendException("No notification transaction sent to $pCode");
     } else {
       final root = await getRootNode(mnemonic: await mnemonic);
@@ -433,12 +433,56 @@ extension PayNym on DogecoinWallet {
     }
   }
 
-  bool hasConnected(String paymentCodeString) {
+  // TODO optimize
-    return db
+  Future<bool> hasConnected(String paymentCodeString) async {
-            .getTransactions(walletId)
+    final myCode = await getPaymentCode();
-            .filter()
+    final myNotificationAddress = myCode.notificationAddress();
-            .address((q) => q.valueEqualTo(paymentCodeString))
+
-            .countSync() >
+    final txns = await db
-        0;
+        .getTransactions(walletId)
+        .filter()
+        .subTypeEqualTo(TransactionSubType.bip47Notification)
+        .findAll();
+
+    for (final tx in txns) {
+      if (tx.address.value?.value == myNotificationAddress) {
+        return true;
+      }
+
+      final blindedCode =
+          tx.outputs.elementAt(1).scriptPubKeyAsm!.split(" ")[1];
+
+      final designatedInput = tx.inputs.first;
+
+      final txPoint = designatedInput.txid.fromHex.toList();
+      final txPointIndex = designatedInput.vout;
+
+      final rev = Uint8List(txPoint.length + 4);
+      Util.copyBytes(Uint8List.fromList(txPoint), 0, rev, 0, txPoint.length);
+      final buffer = rev.buffer.asByteData();
+      buffer.setUint32(txPoint.length, txPointIndex, Endian.little);
+
+      final pubKey = designatedInput.scriptSigAsm!.split(" ")[1].fromHex;
+
+      final root = await getRootNode(mnemonic: await mnemonic);
+      final myPrivateKey =
+          root.derivePath(kPaynymDerivePath).derive(0).privateKey!;
+
+      final S = SecretPoint(myPrivateKey, pubKey);
+
+      final mask = PaymentCode.getMask(S.ecdhSecret(), rev);
+
+      final unBlindedPayload = PaymentCode.blind(blindedCode.fromHex, mask);
+
+      final unBlindedPaymentCode =
+          PaymentCode.initFromPayload(unBlindedPayload);
+
+      if (paymentCodeString == unBlindedPaymentCode.toString()) {
+        return true;
+      }
+    }
+
+    // otherwise return no
+    return false;
   }
 }

lib/services/coins/dogecoin/dogecoin_wallet.dart

@@ -1162,10 +1162,8 @@ class DogecoinWallet extends CoinServiceAPI
         .not()
         .typeEqualTo(isar_models.AddressType.nonWallet)
         .and()
-        .group((q) => q
+        .not()
-            .subTypeEqualTo(isar_models.AddressSubType.receiving)
+        .subTypeEqualTo(isar_models.AddressSubType.nonWallet)
-            .or()
-            .subTypeEqualTo(isar_models.AddressSubType.change))
         .findAll();
     return allAddresses;
   }

lib/services/mixins/electrum_x_parsing.dart

@@ -1,3 +1,4 @@
+import 'package:bip47/src/util.dart';
 import 'package:decimal/decimal.dart';
 import 'package:stackwallet/models/isar/models/isar_models.dart';
 import 'package:stackwallet/utilities/enums/coin_enum.dart';
@@ -148,10 +149,6 @@ mixin ElectrumXParsing {
       amount = amountReceivedInWallet;
     }
 
-    bool isNotificationTx = coin.hasPaynymSupport &&
-        type == TransactionType.incoming &&
-        transactionAddress.subType == AddressSubType.paynymNotification;
-
     List<Output> outs = [];
     List<Input> ins = [];
 
@@ -188,15 +185,27 @@ mixin ElectrumXParsing {
       outs.add(output);
     }
 
+    TransactionSubType txSubType = TransactionSubType.none;
+    if (coin.hasPaynymSupport && outs.length > 1) {
+      List<String>? scriptChunks = outs[1].scriptPubKeyAsm?.split(" ");
+      if (scriptChunks?.length == 2 && scriptChunks?[0] == "OP_RETURN") {
+        final blindedPaymentCode = scriptChunks![1];
+        final bytes = blindedPaymentCode.fromHex;
+
+        // https://en.bitcoin.it/wiki/BIP_0047#Sending
+        if (bytes.length == 80 && bytes.first == 1) {
+          txSubType = TransactionSubType.bip47Notification;
+        }
+      }
+    }
+
     final tx = Transaction(
       walletId: walletId,
       txid: txData["txid"] as String,
       timestamp: txData["blocktime"] as int? ??
           (DateTime.now().millisecondsSinceEpoch ~/ 1000),
       type: type,
-      subType: isNotificationTx
+      subType: txSubType,
-          ? TransactionSubType.bip47Notification
-          : TransactionSubType.none,
       amount: amount,
       fee: fee,
       height: txData["height"] as int?,