Make games rejoinable

1. Disconnect websocket connection before connecting
2. store playerInfo when hosting a game to reuse it when rejoining

lib/api/register.dart

@@ -12,6 +12,10 @@ class PlayerInfo {
     required this.passphrase,
   });
 
+  factory PlayerInfo.empty() {
+    return const PlayerInfo(playerID: null, lobbyID: null, passphrase: null);
+  }
+
   factory PlayerInfo.fromJson(Map<String, dynamic> json) {
     final playerid = UuidValue.fromString(json['playerID']);
     final lobbyid = UuidValue.fromString(json['lobbyID']);
@@ -21,11 +25,24 @@ class PlayerInfo {
         playerID: playerid, lobbyID: lobbyid, passphrase: passphrase);
   }
 
-  Map<String, dynamic> toJson() => {
+  Map<String, dynamic> toJson() {
-        'playerID': playerID,
+    String? pid;
-        'lobbyID': lobbyID,
+    String? lid;
+
+    if (playerID != null) {
+      pid = playerID.toString();
+    }
+
+    if (lobbyID != null) {
+      lid = lobbyID.toString();
+    }
+
+    return {
+      'playerID': pid,
+      'lobbyID': lid,
       'passphrase': passphrase,
     };
+  }
 
   void store() async {
     final SharedPreferences prefs = await SharedPreferences.getInstance();
@@ -42,7 +59,7 @@ class PlayerInfo {
     await prefs.setBool("contains", false);
   }
 
-  Future<PlayerInfo?> get() async {
+  static Future<PlayerInfo?> get() async {
     final SharedPreferences prefs = await SharedPreferences.getInstance();
     var contains = prefs.getBool("contains");
     var playerID = prefs.getString("playerID");

lib/connection/ws_connection.dart

@@ -16,7 +16,6 @@ import 'package:web_socket_channel/web_socket_channel.dart';
 
 class ServerConnection {
   WebSocketChannel? channel;
-  late bool wasConnected = false;
   Stream broadcast = const Stream.empty();
 
   static final ServerConnection _instance = ServerConnection._internal();
@@ -42,6 +41,7 @@ class ServerConnection {
   }
 
   void connect(String playerID, lobbyID, String? passphrase) {
+    disconnectExistingConnection();
     channel = WebSocketChannel.connect(Uri.parse(config.getWebsocketURL()));
 
     send(
@@ -62,6 +62,8 @@ class ServerConnection {
   void disconnectExistingConnection() {
     if (channel == null) return;
     channel!.sink.close();
+
+    broadcast = const Stream.empty();
   }
 
   void handleIncomingData(dynamic data) {

lib/pages/host_game.dart

@@ -27,9 +27,6 @@ class _HostGameWidgetState extends State<HostGameWidget> {
   @override
   void initState() {
     registerResponse = hostPrivateGame();
-    registerResponse.then((value) {
-      value?.store();
-    });
     connectToWebsocket(registerResponse);
     super.initState();
   }
@@ -70,6 +67,7 @@ class _HostGameWidgetState extends State<HostGameWidget> {
                 listener: (context, state) {
                   // We wait for our opponent to connect
                   if (state.opponentConnected) {
+                    snapshot.data?.store();
                     context.pushReplacement('/game', extra: chessGameArgs);
                   }
                 },
@@ -135,7 +133,8 @@ class _HostGameWidgetState extends State<HostGameWidget> {
 
     if (response.statusCode == 200) {
       log(response.body);
-      return PlayerInfo.fromJson(jsonDecode(response.body));
+      var info = PlayerInfo.fromJson(jsonDecode(response.body));
+      return info;
     }
     return null;
   }

lib/pages/lobby_selector.dart

@@ -6,10 +6,10 @@ import 'package:flutter/material.dart';
 import 'package:go_router/go_router.dart';
 import 'package:http/http.dart' as http;
 import 'package:mchess/api/register.dart';
+import 'package:mchess/connection/ws_connection.dart';
 import 'package:mchess/connection_cubit/connection_cubit.dart';
 import 'package:mchess/pages/chess_game.dart';
 import 'package:mchess/utils/config.dart' as config;
-import 'package:shared_preferences/shared_preferences.dart';
 
 class LobbySelector extends StatefulWidget {
   const LobbySelector({super.key});
@@ -25,13 +25,6 @@ class _LobbySelectorState extends State<LobbySelector> {
 
   @override
   Widget build(BuildContext context) {
-    SharedPreferences.getInstance().then((prefs) {
-      final playerID = prefs.getString("playerID");
-      final lobbyID = prefs.getString("lobbyID");
-      final passphrase = prefs.getString("passphrase");
-      log("lobbyID: $lobbyID and playerID: $playerID and passphrase: $passphrase");
-    });
-
     return Scaffold(
       body: Center(
         child: Column(
@@ -57,6 +50,9 @@ class _LobbySelectorState extends State<LobbySelector> {
   }
 
   Future<void> buildJoinOrHostDialog(BuildContext context) {
+    //TODO: find a better place to disconnect old websocket connection
+    ServerConnection.getInstance().disconnectExistingConnection();
+
     return showDialog<void>(
       context: context,
       builder: (BuildContext context) {
@@ -170,13 +166,28 @@ class _LobbySelectorState extends State<LobbySelector> {
   Future<PlayerInfo?> joinPrivateGame(BuildContext context) async {
     http.Response response;
 
-    // server expects us to send the passphrase
+    var existingInfo = await PlayerInfo.get();
-    var info = PlayerInfo(
+
+    log("lobbyID: ${existingInfo?.lobbyID} and playerID: ${existingInfo?.playerID} and passphrase: ${existingInfo?.passphrase}");
+
+    PlayerInfo info;
+    if (existingInfo?.passphrase == phraseController.text) {
+      // We have player info for this exact passphrase
+      info = PlayerInfo(
+          playerID: existingInfo?.playerID,
+          lobbyID: existingInfo?.lobbyID,
+          passphrase: phraseController.text);
+    } else {
+      info = PlayerInfo(
           playerID: null, lobbyID: null, passphrase: phraseController.text);
+    }
+
+    var decodedInfo = jsonEncode(info);
+    log("decodedInfo: $decodedInfo");
 
     try {
       response = await http.post(Uri.parse(config.getJoinURL()),
-          body: jsonEncode(info), headers: {"Accept": "application/json"});
+          body: decodedInfo, headers: {"Accept": "application/json"});
     } catch (e) {
       log(e.toString());
 
@@ -206,6 +217,7 @@ class _LobbySelectorState extends State<LobbySelector> {
 
     if (response.statusCode == HttpStatus.ok) {
       var info = PlayerInfo.fromJson(jsonDecode(response.body));
+      info.store();
       log('Player info received from server: ');
       log('lobbyID: ${info.lobbyID}');
       log('playerID: ${info.playerID}');

lib/utils/config.dart

@@ -1,7 +1,7 @@
 const prodURL = 'chess.sw-gross.de:9999';
 const debugURL = 'localhost:8080';
 
-const useDbgUrl = false;
+const useDbgUrl = true;
 
 String getHostURL() {
   var prot = 'https';