Moved method validateJsonSchema()

lib/data/dao/game_dao.dart

@@ -107,6 +107,7 @@ class GameDao extends DatabaseAccessor<AppDatabase> with _$GameDaoMixin {
           mode: InsertMode.insertOrReplace,
         ),
       );
+
       // Add all groups of the games in batch
       await db.batch(
         (b) => b.insertAll(
@@ -125,8 +126,42 @@ class GameDao extends DatabaseAccessor<AppDatabase> with _$GameDaoMixin {
         ),
       );
 
-      // Add all players of the games in batch
-      await db.batch((b) async {
+      // Add all players of the games in batch (unique)
+      final uniquePlayers = <String, Player>{};
+      for (final game in games) {
+        if (game.players != null) {
+          for (final p in game.players!) {
+            uniquePlayers[p.id] = p;
+          }
+        }
+        // Also include members of groups
+        if (game.group != null) {
+          for (final m in game.group!.members) {
+            uniquePlayers[m.id] = m;
+          }
+        }
+      }
+
+      if (uniquePlayers.isNotEmpty) {
+        await db.batch(
+          (b) => b.insertAll(
+            db.playerTable,
+            uniquePlayers.values
+                .map(
+                  (p) => PlayerTableCompanion.insert(
+                    id: p.id,
+                    name: p.name,
+                    createdAt: p.createdAt,
+                  ),
+                )
+                .toList(),
+            mode: InsertMode.insertOrReplace,
+          ),
+        );
+      }
+
+      // Add all player-game associations in batch
+      await db.batch((b) {
         for (final game in games) {
           if (game.players != null) {
             for (final p in game.players ?? []) {
@@ -143,8 +178,26 @@ class GameDao extends DatabaseAccessor<AppDatabase> with _$GameDaoMixin {
         }
       });
 
+      // Add all player-group associations in batch
+      await db.batch((b) {
+        for (final game in games) {
+          if (game.group != null) {
+            for (final m in game.group!.members) {
+              b.insert(
+                db.playerGroupTable,
+                PlayerGroupTableCompanion.insert(
+                  playerId: m.id,
+                  groupId: game.group!.id,
+                ),
+                mode: InsertMode.insertOrReplace,
+              );
+            }
+          }
+        }
+      });
+
       // Add all group-game associations in batch
-      await db.batch((b) async {
+      await db.batch((b) {
         for (final game in games) {
           if (game.group != null) {
             b.insert(
@@ -158,25 +211,6 @@ class GameDao extends DatabaseAccessor<AppDatabase> with _$GameDaoMixin {
           }
         }
       });
-
-      // Add all player-game associations in batch
-      await db.batch((b) async {
-        for (final game in games) {
-          if (game.players != null) {
-            for (final p in game.players ?? []) {
-              b.insert(
-                db.playerTable,
-                PlayerTableCompanion.insert(
-                  id: p.id,
-                  name: p.name,
-                  createdAt: p.createdAt,
-                ),
-                mode: InsertMode.insertOrReplace,
-              );
-            }
-          }
-        }
-      });
     });
   }
 

lib/data/dao/group_dao.dart

@@ -87,10 +87,17 @@ class GroupDao extends DatabaseAccessor<AppDatabase> with _$GroupDaoMixin {
   Future<void> addGroups({required List<Group> groups}) async {
     if (groups.isEmpty) return;
     await db.transaction(() async {
+      // Deduplicate groups by id - keep first occurrence
+      final Map<String, Group> uniqueGroups = {};
+      for (final g in groups) {
+        uniqueGroups.putIfAbsent(g.id, () => g);
+      }
+
+      // Insert unique groups in batch
       await db.batch(
         (b) => b.insertAll(
           groupTable,
-          groups
+          uniqueGroups.values
               .map(
                 (group) => GroupTableCompanion.insert(
                   id: group.id,
@@ -103,17 +110,24 @@ class GroupDao extends DatabaseAccessor<AppDatabase> with _$GroupDaoMixin {
         ),
       );
 
-      for (final group in groups) {
-        await db.playerDao.addPlayers(players: group.members);
+      // Collect unique players from all groups
+      final uniquePlayers = <String, Player>{};
+      for (final g in uniqueGroups.values) {
+        for (final m in g.members) {
+          uniquePlayers[m.id] = m;
+        }
+      }
 
+      if (uniquePlayers.isNotEmpty) {
         await db.batch(
           (b) => b.insertAll(
-            db.playerGroupTable,
-            group.members
+            db.playerTable,
+            uniquePlayers.values
                 .map(
-                  (member) => PlayerGroupTableCompanion.insert(
-                    playerId: member.id,
-                    groupId: group.id,
+                  (p) => PlayerTableCompanion.insert(
+                    id: p.id,
+                    name: p.name,
+                    createdAt: p.createdAt,
                   ),
                 )
                 .toList(),
@@ -121,6 +135,29 @@ class GroupDao extends DatabaseAccessor<AppDatabase> with _$GroupDaoMixin {
           ),
         );
       }
+
+      // Prepare all player-group associations in one list (unique pairs)
+      final Set<String> seenPairs = {};
+      final List<PlayerGroupTableCompanion> pgRows = [];
+      for (final g in uniqueGroups.values) {
+        for (final m in g.members) {
+          final key = '${m.id}|${g.id}';
+          if (!seenPairs.contains(key)) {
+            seenPairs.add(key);
+            pgRows.add(
+              PlayerGroupTableCompanion.insert(playerId: m.id, groupId: g.id),
+            );
+          }
+        }
+      }
+
+      if (pgRows.isNotEmpty) {
+        await db.batch((b) {
+          for (final pg in pgRows) {
+            b.insert(db.playerGroupTable, pg, mode: InsertMode.insertOrReplace);
+          }
+        });
+      }
     });
   }
 

lib/presentation/views/main_menu/settings_view.dart

@@ -1,39 +1,14 @@
-import 'dart:convert';
-
 import 'package:flutter/material.dart';
-import 'package:flutter/services.dart';
 import 'package:game_tracker/core/custom_theme.dart';
 import 'package:game_tracker/core/enums.dart';
 import 'package:game_tracker/presentation/widgets/tiles/settings_list_tile.dart';
 import 'package:game_tracker/services/data_transfer_service.dart';
-import 'package:json_schema/json_schema.dart';
 
 class SettingsView extends StatefulWidget {
   const SettingsView({super.key});
 
   @override
   State<SettingsView> createState() => _SettingsViewState();
-
-  static Future<bool> validateJsonSchema(String jsonString) async {
-    final String schemaString;
-
-    schemaString = await rootBundle.loadString('assets/schema.json');
-
-    try {
-      final schema = JsonSchema.create(json.decode(schemaString));
-      final jsonData = json.decode(jsonString);
-      final result = schema.validate(jsonData);
-
-      if (result.isValid) {
-        return true;
-      }
-      return false;
-    } catch (e, stack) {
-      print('[validateJsonSchema] $e');
-      print(stack);
-      return false;
-    }
-  }
 }
 
 class _SettingsViewState extends State<SettingsView> {

lib/services/data_transfer_service.dart

@@ -1,15 +1,15 @@
 import 'dart:convert';
 import 'dart:io';
-import 'dart:typed_data';
 
 import 'package:file_picker/file_picker.dart';
 import 'package:flutter/material.dart';
+import 'package:flutter/services.dart';
 import 'package:game_tracker/core/enums.dart';
 import 'package:game_tracker/data/db/database.dart';
 import 'package:game_tracker/data/dto/game.dart';
 import 'package:game_tracker/data/dto/group.dart';
 import 'package:game_tracker/data/dto/player.dart';
-import 'package:game_tracker/presentation/views/main_menu/settings_view.dart';
+import 'package:json_schema/json_schema.dart';
 import 'package:provider/provider.dart';
 
 class DataTransferService {
@@ -85,7 +85,7 @@ class DataTransferService {
         return ImportResult.fileReadError;
       }
 
-      if (await SettingsView.validateJsonSchema(jsonString)) {
+      if (await _validateJsonSchema(jsonString)) {
         final Map<String, dynamic> jsonData =
             json.decode(jsonString) as Map<String, dynamic>;
 
@@ -136,4 +136,26 @@ class DataTransferService {
     if (file.path != null) return await File(file.path!).readAsString();
     return null;
   }
+
+  /// Validates the given JSON string against the predefined schema.
+  static Future<bool> _validateJsonSchema(String jsonString) async {
+    final String schemaString;
+
+    schemaString = await rootBundle.loadString('assets/schema.json');
+
+    try {
+      final schema = JsonSchema.create(json.decode(schemaString));
+      final jsonData = json.decode(jsonString);
+      final result = schema.validate(jsonData);
+
+      if (result.isValid) {
+        return true;
+      }
+      return false;
+    } catch (e, stack) {
+      print('[validateJsonSchema] $e');
+      print(stack);
+      return false;
+    }
+  }
 }