Mark successful payjoin sessions in storage.

Payjoin sessions marked 'complete' do not get spawned. This reduces the
number of isolates spawned on resume or restart.

Mark rather than delete so that the historic status may eventually be
shown in transaction history.

lib/_pkg/payjoin/manager.dart

@@ -113,12 +113,14 @@ class PayjoinManager {
               completer.complete(err);
               return;
             }
+            // Successfully sent payjoin
             PayjoinEventBus().emit(
               PayjoinBroadcastEvent(
                 txid: wtxid!.$2,
               ),
             );
             await _cleanupSession(pjUri);
+            await _payjoinStorage.markSenderSessionComplete(pjUri);
             completer.complete(null);
           }
         } else if (message is Err) {
@@ -244,6 +246,7 @@ class PayjoinManager {
                 });
               case 'proposal_sent':
                 await _cleanupSession(receiver.id());
+                await _payjoinStorage.markSenderSessionComplete(receiver.id());
                 completer.complete(null);
             }
           } catch (e) {
@@ -295,10 +298,13 @@ class PayjoinManager {
     if (senderErr != null) throw senderErr;
 
     final filteredReceivers = receiverSessions
-        .where((session) => session.walletId == wallet.id)
+        .where((session) =>
+            session.walletId == wallet.id &&
+            session.status != PayjoinSessionStatus.success)
         .toList();
     final filteredSenders = senderSessions.where((session) {
-      return session.walletId == wallet.id;
+      return session.walletId == wallet.id &&
+          session.status != PayjoinSessionStatus.success;
     }).toList();
 
     final spawnedReceivers = filteredReceivers.map((session) {
@@ -359,8 +365,19 @@ class PayjoinManager {
   }
 }
 
+enum PayjoinSessionStatus {
+  pending,
+  success,
+}
+
 class SendSession {
-  SendSession(this._isTestnet, this._sender, this._walletId, this._pjUri);
+  SendSession(
+    this._isTestnet,
+    this._sender,
+    this._walletId,
+    this._pjUri,
+    this._status,
+  );
 
   // Deserialize JSON to Receiver
   factory SendSession.fromJson(Map<String, dynamic> json) {
@@ -369,54 +386,69 @@ class SendSession {
       Sender.fromJson(json['sender'] as String),
       json['walletId'] as String,
       json['pjUri'] as String,
+      json['status'] != null
+          ? PayjoinSessionStatus.values.byName(json['status'] as String)
+          : null,
     );
   }
 
   final bool _isTestnet;
   final Sender _sender;
   final String _walletId;
   final String _pjUri;
-
+  final PayjoinSessionStatus? _status;
   bool get isTestnet => _isTestnet;
   Sender get sender => _sender;
   String get walletId => _walletId;
   String get pjUri => _pjUri;
-
+  PayjoinSessionStatus? get status => _status;
   // Serialize Receiver to JSON
   Map<String, dynamic> toJson() {
     return {
       'isTestnet': _isTestnet,
       'sender': _sender.toJson(),
       'walletId': _walletId,
       'pjUri': _pjUri,
+      'status': _status?.name,
     };
   }
 }
 
 class RecvSession {
-  RecvSession(this._isTestnet, this._receiver, this._walletId);
+  RecvSession(
+    this._isTestnet,
+    this._receiver,
+    this._walletId,
+    this._status,
+  );
 
   factory RecvSession.fromJson(Map<String, dynamic> json) {
     return RecvSession(
       json['isTestnet'] as bool,
       Receiver.fromJson(json['receiver'] as String),
       json['walletId'] as String,
+      json['status'] != null
+          ? PayjoinSessionStatus.values.byName(json['status'] as String)
+          : null,
     );
   }
 
   final bool _isTestnet;
   final Receiver _receiver;
   final String _walletId;
+  final PayjoinSessionStatus? _status;
 
   bool get isTestnet => _isTestnet;
   Receiver get receiver => _receiver;
   String get walletId => _walletId;
+  PayjoinSessionStatus? get status => _status;
 
   Map<String, dynamic> toJson() {
     return {
       'isTestnet': isTestnet,
       'receiver': receiver.toJson(),
       'walletId': walletId,
+      'status': _status?.name,
     };
   }
 }

lib/_pkg/payjoin/storage.dart

@@ -42,6 +42,7 @@ class PayjoinStorage {
         isTestnet,
         receiver,
         walletId,
+        PayjoinSessionStatus.pending,
       );
 
       await _hiveStorage.saveValue(
@@ -73,6 +74,28 @@ class PayjoinStorage {
     }
   }
 
+  Future<Err?> markReceiverSessionComplete(String sessionId) async {
+    try {
+      final (session, err) = await readReceiverSession(sessionId);
+      if (err != null) return err;
+
+      final updatedSession = RecvSession(
+        session!.isTestnet,
+        session.receiver,
+        session.walletId,
+        PayjoinSessionStatus.success,
+      );
+
+      await _hiveStorage.saveValue(
+        key: receiverPrefix + sessionId,
+        value: jsonEncode(updatedSession.toJson()),
+      );
+      return null;
+    } catch (e) {
+      return Err(e.toString());
+    }
+  }
+
   Future<(List<RecvSession>, Err?)> readAllReceivers() async {
     //deleteAllSessions();
     try {
@@ -109,6 +132,7 @@ class PayjoinStorage {
         sender,
         walletId,
         pjUrl,
+        PayjoinSessionStatus.pending,
       );
 
       await _hiveStorage.saveValue(
@@ -139,6 +163,29 @@ class PayjoinStorage {
     }
   }
 
+  Future<Err?> markSenderSessionComplete(String pjUrl) async {
+    try {
+      final (session, err) = await readSenderSession(pjUrl);
+      if (err != null) return err;
+
+      final updatedSession = SendSession(
+        session!.isTestnet,
+        session.sender,
+        session.walletId,
+        session.pjUri,
+        PayjoinSessionStatus.success,
+      );
+
+      await _hiveStorage.saveValue(
+        key: senderPrefix + pjUrl,
+        value: jsonEncode(updatedSession.toJson()),
+      );
+      return null;
+    } catch (e) {
+      return Err(e.toString());
+    }
+  }
+
   Future<(List<SendSession>, Err?)> readAllSenders() async {
     try {
       final (allData, err) = await _hiveStorage.getAll();