filter bangs by categories

app/lib/features/bangs/domain/repositories/bang_data.dart

@@ -1,3 +1,5 @@
+import 'dart:convert';
+
 import 'package:bang_navigator/domain/services/generic_website.dart';
 import 'package:bang_navigator/features/bangs/data/database/database.dart';
 import 'package:bang_navigator/features/bangs/data/models/bang.dart';
@@ -27,6 +29,15 @@ class BangDataRepository extends _$BangDataRepository {
     }
   }
 
+  Stream<Map<String, List<String>>> watchCategories() {
+    return _db.categoriesJson().watchSingle().map((json) {
+      final decoded = jsonDecode(json) as Map<String, dynamic>;
+      return decoded.map(
+        (key, value) => MapEntry(key, (value as List<dynamic>).cast()),
+      );
+    });
+  }
+
   Stream<int> watchBangCount(BangGroup group) {
     return _db.bangDao.getBangCount(groups: [group]).watchSingle();
   }

app/lib/features/bangs/domain/repositories/bang_data.g.dart

@@ -7,7 +7,7 @@ part of 'bang_data.dart';
 // **************************************************************************
 
 String _$bangDataRepositoryHash() =>
-    r'6ac3a59546f6d7e22f3c37aacd43a3579978eb50';
+    r'a6e4017a54516571af553426b0e8e3597d19f779';
 
 /// See also [BangDataRepository].
 @ProviderFor(BangDataRepository)