add a shit ton of feature for the custom srs

.gitignore

@@ -46,3 +46,6 @@ app.*.map.json
 
 *.jks
 gradle.properties
+
+# Environment variables
+.env

lib/main.dart

@@ -1,10 +1,12 @@
 import 'package:flutter/material.dart';
 import 'package:provider/provider.dart';
+import 'package:flutter_dotenv/flutter_dotenv.dart';
 import 'src/services/deck_repository.dart';
 import 'src/screens/start_screen.dart';
 
 void main() async {
   WidgetsFlutterBinding.ensureInitialized();
+  await dotenv.load(fileName: ".env");
 
   runApp(
     Provider<DeckRepository>(

lib/src/models/custom_kanji_item.dart

@@ -3,11 +3,17 @@ class CustomKanjiItem {
   final String characters;
   final String meaning;
   final String? kanji;
+  final bool useInterval;
+  int srsLevel;
+  DateTime? nextReview;
 
   CustomKanjiItem({
     required this.characters,
     required this.meaning,
     this.kanji,
+    this.useInterval = false,
+    this.srsLevel = 0,
+    this.nextReview,
   });
 
   factory CustomKanjiItem.fromJson(Map<String, dynamic> json) {
@@ -15,6 +21,11 @@ class CustomKanjiItem {
       characters: json['characters'] as String,
       meaning: json['meaning'] as String,
       kanji: json['kanji'] as String?,
+      useInterval: json['useInterval'] as bool? ?? false,
+      srsLevel: json['srsLevel'] as int? ?? 0,
+      nextReview: json['nextReview'] != null
+          ? DateTime.parse(json['nextReview'] as String)
+          : null,
     );
   }
 
@@ -23,6 +34,9 @@ class CustomKanjiItem {
       'characters': characters,
       'meaning': meaning,
       'kanji': kanji,
+      'useInterval': useInterval,
+      'srsLevel': srsLevel,
+      'nextReview': nextReview?.toIso8601String(),
     };
   }
 }

lib/src/screens/add_card_screen.dart

@@ -18,6 +18,7 @@ class _AddCardScreenState extends State<AddCardScreen> {
   final _kanjiController = TextEditingController();
   final _kanaKit = const KanaKit();
   final _deckRepository = CustomDeckRepository();
+  bool _useInterval = false;
 
   @override
   void initState() {
@@ -53,6 +54,8 @@ class _AddCardScreenState extends State<AddCardScreen> {
         characters: _japaneseController.text,
         meaning: _englishController.text,
         kanji: _kanjiController.text.isNotEmpty ? _kanjiController.text : null,
+        useInterval: _useInterval,
+        nextReview: _useInterval ? DateTime.now() : null,
       );
       _deckRepository.addCard(newItem);
       Navigator.of(context).pop();
@@ -106,6 +109,16 @@ class _AddCardScreenState extends State<AddCardScreen> {
                   return null;
                 },
               ),
+              const SizedBox(height: 16),
+              SwitchListTile(
+                title: const Text('Use Interval-based SRS'),
+                value: _useInterval,
+                onChanged: (value) {
+                  setState(() {
+                    _useInterval = value;
+                  });
+                },
+              ),
               const SizedBox(height: 32),
               ElevatedButton(
                 onPressed: _saveCard,

lib/src/screens/browse_screen.dart

@@ -2,7 +2,10 @@ import 'package:flutter/material.dart';
 import 'package:provider/provider.dart';
 import '../models/kanji_item.dart';
 import '../services/deck_repository.dart';
+import '../services/custom_deck_repository.dart';
+import '../models/custom_kanji_item.dart';
 import 'settings_screen.dart';
+import 'custom_card_details_screen.dart';
 
 class BrowseScreen extends StatefulWidget {
   const BrowseScreen({super.key});
@@ -18,11 +21,17 @@ class _BrowseScreenState extends State<BrowseScreen> with SingleTickerProviderSt
 
   List<KanjiItem> _kanjiDeck = [];
   List<VocabularyItem> _vocabDeck = [];
+  List<CustomKanjiItem> _customDeck = [];
   Map<int, List<KanjiItem>> _kanjiByLevel = {};
   Map<int, List<VocabularyItem>> _vocabByLevel = {};
   List<int> _kanjiSortedLevels = [];
   List<int> _vocabSortedLevels = [];
 
+  final _customDeckRepository = CustomDeckRepository();
+
+  bool _isSelectionMode = false;
+  List<CustomKanjiItem> _selectedItems = [];
+
   bool _loading = true;
   String _status = 'Loading...';
   int _currentKanjiPage = 0;
@@ -32,7 +41,7 @@ class _BrowseScreenState extends State<BrowseScreen> with SingleTickerProviderSt
   @override
   void initState() {
     super.initState();
-    _tabController = TabController(length: 2, vsync: this);
+    _tabController = TabController(length: 3, vsync: this);
     _kanjiPageController = PageController();
     _vocabPageController = PageController();
 
@@ -57,6 +66,7 @@ class _BrowseScreenState extends State<BrowseScreen> with SingleTickerProviderSt
     });
 
     _loadDecks();
+    _loadCustomDeck();
   }
 
   @override
@@ -67,75 +77,16 @@ class _BrowseScreenState extends State<BrowseScreen> with SingleTickerProviderSt
     super.dispose();
   }
 
-  Future<void> _loadDecks() async {
+  Future<void> _loadCustomDeck() async {
-    setState(() => _loading = true);
+    final customDeck = await _customDeckRepository.getCustomDeck();
-    try {
-      final repo = Provider.of<DeckRepository>(context, listen: false);
-      await repo.loadApiKey();
-      final apiKey = repo.apiKey;
-
-      if (apiKey == null || apiKey.isEmpty) {
     setState(() {
-          _apiKeyMissing = true;
+      _customDeck = customDeck;
-          _loading = false;
-        });
-        return;
-      }
-
-      var kanji = await repo.loadKanji();
-      if (kanji.isEmpty || kanji.every((k) => k.level == 0)) {
-        setState(() => _status = 'Fetching kanji from WaniKani...');
-        kanji = await repo.fetchAndCacheFromWk(apiKey);
-      }
-
-      var vocab = await repo.loadVocabulary();
-      if (vocab.isEmpty || vocab.every((v) => v.level == 0)) {
-        setState(() => _status = 'Fetching vocabulary from WaniKani...');
-        vocab = await repo.fetchAndCacheVocabularyFromWk(apiKey);
-      }
-
-      _kanjiDeck = kanji;
-      _vocabDeck = vocab;
-      _groupItemsByLevel();
-
-      setState(() {
-        _loading = false;
-        _status =
-            'Loaded ${_kanjiDeck.length} kanji and ${_vocabDeck.length} vocabulary.';
-        _apiKeyMissing = false;
-      });
-    } catch (e) {
-      setState(() {
-        _status = 'Error: $e';
-        _loading = false;
     });
   }
-  }
 
-  void _groupItemsByLevel() {
+  Widget _buildWaniKaniTab(Widget child) {
-    _kanjiByLevel = {};
-    for (final item in _kanjiDeck) {
-      if (item.level > 0) {
-        (_kanjiByLevel[item.level] ??= []).add(item);
-      }
-    }
-    _kanjiSortedLevels = _kanjiByLevel.keys.toList()..sort();
-
-    _vocabByLevel = {};
-    for (final item in _vocabDeck) {
-      if (item.level > 0) {
-        (_vocabByLevel[item.level] ??= []).add(item);
-      }
-    }
-    _vocabSortedLevels = _vocabByLevel.keys.toList()..sort();
-  }
-
-  @override
-  Widget build(BuildContext context) {
     if (_apiKeyMissing) {
-      return Scaffold(
+      return Center(
-        appBar: AppBar(title: const Text('Browse')),
-        body: Center(
         child: Column(
           mainAxisAlignment: MainAxisAlignment.center,
           children: [
@@ -152,24 +103,11 @@ class _BrowseScreenState extends State<BrowseScreen> with SingleTickerProviderSt
             ),
           ],
         ),
-        ),
       );
     }
 
-    return Scaffold(
+    if (_loading) {
-      appBar: AppBar(
+      return Center(
-        title: const Text('Browse'),
-        bottom: TabBar(
-          controller: _tabController,
-          tabs: const [
-            Tab(text: 'Kanji'),
-            Tab(text: 'Vocabulary'),
-          ],
-        ),
-      ),
-      backgroundColor: const Color(0xFF121212),
-      body: _loading
-          ? Center(
         child: Column(
           mainAxisAlignment: MainAxisAlignment.center,
           children: [
@@ -178,35 +116,21 @@ class _BrowseScreenState extends State<BrowseScreen> with SingleTickerProviderSt
             Text(_status, style: const TextStyle(color: Colors.white)),
           ],
         ),
-            )
-          : Column(
-              children: [
-                Expanded(
-                  child: TabBarView(
-                    controller: _tabController,
-                    children: [
-                      _buildPaginatedView(
-                          _kanjiByLevel,
-                          _kanjiSortedLevels,
-                          _kanjiPageController,
-                          (items) => _buildGridView(items.cast<KanjiItem>())),
-                      _buildPaginatedView(
-                          _vocabByLevel,
-                          _vocabSortedLevels,
-                          _vocabPageController,
-                          (items) => _buildListView(items.cast<VocabularyItem>())),
-                    ],
-                  ),
-                ),
-                SafeArea(
-                  top: false,
-                  child: _buildLevelSelector(),
-                ),
-              ],
-            ),
       );
     }
 
+    return child;
+  }
+
+  Widget _buildCustomSrsTab() {
+    if (_customDeck.isEmpty) {
+      return const Center(
+        child: Text('No custom cards yet.', style: TextStyle(color: Colors.white)),
+      );
+    }
+    return _buildCustomGridView(_customDeck);
+  }
+
   Widget _buildPaginatedView(
       Map<int, List<dynamic>> groupedItems,
       List<int> sortedLevels,
@@ -452,7 +376,7 @@ class _BrowseScreenState extends State<BrowseScreen> with SingleTickerProviderSt
               if (kanji.onyomi.isEmpty && kanji.kunyomi.isEmpty)
                 const Text(
                   'No readings available.',
-                  style: TextStyle(color: Colors.white),
+                  style: const TextStyle(color: Colors.white),
                 ),
             ],
           ),
@@ -467,4 +391,290 @@ class _BrowseScreenState extends State<BrowseScreen> with SingleTickerProviderSt
       },
     );
   }
+
+  Future<void> _loadDecks() async {
+    setState(() => _loading = true);
+    try {
+      final repo = Provider.of<DeckRepository>(context, listen: false);
+      await repo.loadApiKey();
+      final apiKey = repo.apiKey;
+
+      if (apiKey == null || apiKey.isEmpty) {
+        setState(() {
+          _apiKeyMissing = true;
+          _loading = false;
+        });
+        return;
+      }
+
+      var kanji = await repo.loadKanji();
+      if (kanji.isEmpty || kanji.every((k) => k.level == 0)) {
+        setState(() => _status = 'Fetching kanji from WaniKani...');
+        kanji = await repo.fetchAndCacheFromWk(apiKey);
+      }
+
+      var vocab = await repo.loadVocabulary();
+      if (vocab.isEmpty || vocab.every((v) => v.level == 0)) {
+        setState(() => _status = 'Fetching vocabulary from WaniKani...');
+        vocab = await repo.fetchAndCacheVocabularyFromWk(apiKey);
+      }
+
+      _kanjiDeck = kanji;
+      _vocabDeck = vocab;
+      _groupItemsByLevel();
+
+      setState(() {
+        _loading = false;
+        _status =
+            'Loaded ${_kanjiDeck.length} kanji and ${_vocabDeck.length} vocabulary.';
+        _apiKeyMissing = false;
+      });
+    } catch (e) {
+      setState(() {
+        _status = 'Error: $e';
+        _loading = false;
+      });
+    }
+  }
+
+  void _groupItemsByLevel() {
+    _kanjiByLevel = {};
+    for (final item in _kanjiDeck) {
+      if (item.level > 0) {
+        (_kanjiByLevel[item.level] ??= []).add(item);
+      }
+    }
+    _kanjiSortedLevels = _kanjiByLevel.keys.toList()..sort();
+
+    _vocabByLevel = {};
+    for (final item in _vocabDeck) {
+      if (item.level > 0) {
+        (_vocabByLevel[item.level] ??= []).add(item);
+      }
+    }
+    _vocabSortedLevels = _vocabByLevel.keys.toList()..sort();
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    return Scaffold(
+      appBar: _isSelectionMode ? _buildSelectionAppBar() : _buildDefaultAppBar(),
+      backgroundColor: const Color(0xFF121212),
+      body: Column(
+        children: [
+          Expanded(
+            child: TabBarView(
+              controller: _tabController,
+              children: [
+                _buildWaniKaniTab(
+                  _buildPaginatedView(
+                      _kanjiByLevel,
+                      _kanjiSortedLevels,
+                      _kanjiPageController,
+                      (items) => _buildGridView(items.cast<KanjiItem>())),
+                ),
+                _buildWaniKaniTab(
+                  _buildPaginatedView(
+                      _vocabByLevel,
+                      _vocabSortedLevels,
+                      _vocabPageController,
+                      (items) => _buildListView(items.cast<VocabularyItem>())),
+                ),
+                _buildCustomSrsTab(),
+              ],
+            ),
+          ),
+          if (!_isSelectionMode)
+            SafeArea(
+              top: false,
+              child: _tabController.index < 2 ? _buildLevelSelector() : const SizedBox.shrink(),
+            ),
+        ],
+      ),
+    );
+  }
+
+  AppBar _buildDefaultAppBar() {
+    return AppBar(
+      title: const Text('Browse'),
+      bottom: TabBar(
+        controller: _tabController,
+        tabs: const [
+          Tab(text: 'Kanji'),
+          Tab(text: 'Vocabulary'),
+          Tab(text: 'Custom SRS'),
+        ],
+      ),
+    );
+  }
+
+  AppBar _buildSelectionAppBar() {
+    return AppBar(
+      leading: IconButton(
+        icon: const Icon(Icons.close),
+        onPressed: () {
+          setState(() {
+            _isSelectionMode = false;
+            _selectedItems.clear();
+          });
+        },
+      ),
+      title: Text('${_selectedItems.length} selected'),
+      actions: [
+        IconButton(
+          icon: const Icon(Icons.select_all),
+          onPressed: _selectAll,
+        ),
+        IconButton(
+          icon: const Icon(Icons.delete),
+          onPressed: _deleteSelected,
+        ),
+        IconButton(
+          icon: const Icon(Icons.timer_off),
+          onPressed: _toggleIntervalForSelected,
+        ),
+      ],
+    );
+  }
+
+  void _selectAll() {
+    setState(() {
+      if (_selectedItems.length == _customDeck.length) {
+        _selectedItems.clear();
+      } else {
+        _selectedItems = List.from(_customDeck);
+      }
+    });
+  }
+
+  void _deleteSelected() {
+    showDialog(
+      context: context,
+      builder: (context) => AlertDialog(
+        title: const Text('Delete Selected'),
+        content: Text('Are you sure you want to delete ${_selectedItems.length} cards?'),
+        actions: [
+          TextButton(
+            onPressed: () => Navigator.of(context).pop(),
+            child: const Text('Cancel'),
+          ),
+          TextButton(
+            onPressed: () async {
+              for (final item in _selectedItems) {
+                await _customDeckRepository.deleteCard(item);
+              }
+              setState(() {
+                _isSelectionMode = false;
+                _selectedItems.clear();
+              });
+              _loadCustomDeck();
+              Navigator.of(context).pop();
+            },
+            child: const Text('Delete'),
+          ),
+        ],
+      ),
+    );
+  }
+
+  void _toggleIntervalForSelected() {
+    for (final item in _selectedItems) {
+      final updatedItem = CustomKanjiItem(
+        characters: item.characters,
+        meaning: item.meaning,
+        kanji: item.kanji,
+        useInterval: !item.useInterval,
+        srsLevel: item.srsLevel,
+        nextReview: item.nextReview,
+      );
+      _customDeckRepository.updateCard(updatedItem);
+    }
+    setState(() {
+      _isSelectionMode = false;
+      _selectedItems.clear();
+    });
+    _loadCustomDeck();
+  }
+
+  Widget _buildCustomGridView(List<CustomKanjiItem> items) {
+    return GridView.builder(
+      gridDelegate: const SliverGridDelegateWithMaxCrossAxisExtent(
+        maxCrossAxisExtent: 200,
+        childAspectRatio: 1.2,
+        crossAxisSpacing: 8,
+        mainAxisSpacing: 8,
+      ),
+      itemCount: items.length,
+      itemBuilder: (context, index) {
+        final item = items[index];
+        final isSelected = _selectedItems.contains(item);
+        return GestureDetector(
+          onLongPress: () {
+            setState(() {
+              _isSelectionMode = true;
+              _selectedItems.add(item);
+            });
+          },
+          onTap: () {
+            if (_isSelectionMode) {
+              setState(() {
+                if (isSelected) {
+                  _selectedItems.remove(item);
+                  if (_selectedItems.isEmpty) {
+                    _isSelectionMode = false;
+                  }
+                } else {
+                  _selectedItems.add(item);
+                }
+              });
+            } else {
+              Navigator.of(context).push(
+                MaterialPageRoute(
+                  builder: (_) => CustomCardDetailsScreen(
+                    item: item,
+                    repository: _customDeckRepository,
+                  ),
+                ),
+              ).then((_) => _loadCustomDeck());
+            }
+          },
+          child: Card(
+            color: isSelected
+                ? Colors.blue.withOpacity(0.5)
+                : item.useInterval
+                    ? Color.lerp(const Color(0xFF1E1E1E), Colors.blue, 0.1)
+                    : const Color(0xFF1E1E1E),
+            child: Padding(
+              padding: const EdgeInsets.all(8.0),
+              child: Column(
+                mainAxisAlignment: MainAxisAlignment.center,
+                children: [
+                  FittedBox(
+                    fit: BoxFit.scaleDown,
+                    child: Text(
+                      item.kanji ?? item.characters,
+                      style: const TextStyle(fontSize: 32, color: Colors.white),
+                      textAlign: TextAlign.center,
+                    ),
+                  ),
+                  const SizedBox(height: 8),
+                  Text(
+                    item.meaning,
+                    style: const TextStyle(color: Colors.grey, fontSize: 16),
+                    textAlign: TextAlign.center,
+                    overflow: TextOverflow.ellipsis,
+                  ),
+                  const SizedBox(height: 8),
+                  _buildSrsIndicator(item.srsLevel),
+                ],
+              ),
+            ),
+          ),
+        );
+      },
+      padding: const EdgeInsets.all(8),
+    );
+  }
+
+
 }

lib/src/screens/custom_card_details_screen.dart

@@ -0,0 +1,127 @@
+import 'package:flutter/material.dart';
+import '../models/custom_kanji_item.dart';
+import '../services/custom_deck_repository.dart';
+
+class CustomCardDetailsScreen extends StatefulWidget {
+  final CustomKanjiItem item;
+  final CustomDeckRepository repository;
+
+  const CustomCardDetailsScreen(
+      {super.key, required this.item, required this.repository});
+
+  @override
+  State<CustomCardDetailsScreen> createState() =>
+      _CustomCardDetailsScreenState();
+}
+
+class _CustomCardDetailsScreenState extends State<CustomCardDetailsScreen> {
+  late TextEditingController _japaneseController;
+  late TextEditingController _englishController;
+  late TextEditingController _kanjiController;
+  late bool _useInterval;
+  late int _srsLevel;
+
+  @override
+  void initState() {
+    super.initState();
+    _japaneseController = TextEditingController(text: widget.item.characters);
+    _englishController = TextEditingController(text: widget.item.meaning);
+    _kanjiController = TextEditingController(text: widget.item.kanji);
+    _useInterval = widget.item.useInterval;
+    _srsLevel = widget.item.srsLevel;
+  }
+
+  @override
+  void dispose() {
+    _japaneseController.dispose();
+    _englishController.dispose();
+    _kanjiController.dispose();
+    super.dispose();
+  }
+
+  void _saveChanges() {
+    final updatedItem = CustomKanjiItem(
+      characters: _japaneseController.text,
+      meaning: _englishController.text,
+      kanji: _kanjiController.text,
+      useInterval: _useInterval,
+      srsLevel: _srsLevel,
+      nextReview: widget.item.nextReview,
+    );
+    widget.repository.updateCard(updatedItem);
+    Navigator.of(context).pop(true);
+  }
+
+  void _deleteCard() {
+    showDialog(
+      context: context,
+      builder: (context) => AlertDialog(
+        title: const Text('Delete Card'),
+        content: const Text('Are you sure you want to delete this card?'),
+        actions: [
+          TextButton(
+            onPressed: () => Navigator.of(context).pop(),
+            child: const Text('Cancel'),
+          ),
+          TextButton(
+            onPressed: () {
+              widget.repository.deleteCard(widget.item);
+              Navigator.of(context).pop();
+              Navigator.of(context).pop(true);
+            },
+            child: const Text('Delete'),
+          ),
+        ],
+      ),
+    );
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    return Scaffold(
+      appBar: AppBar(
+        title: const Text('Edit Card'),
+        actions: [
+          IconButton(
+            icon: const Icon(Icons.delete),
+            onPressed: _deleteCard,
+          ),
+        ],
+      ),
+      body: Padding(
+        padding: const EdgeInsets.all(16.0),
+        child: Column(
+          children: [
+            TextFormField(
+              controller: _japaneseController,
+              decoration: const InputDecoration(labelText: 'Japanese (Kana)'),
+            ),
+            TextFormField(
+              controller: _kanjiController,
+              decoration: const InputDecoration(labelText: 'Japanese (Kanji)'),
+            ),
+            TextFormField(
+              controller: _englishController,
+              decoration: const InputDecoration(labelText: 'English'),
+            ),
+            SwitchListTile(
+              title: const Text('Use Interval SRS'),
+              value: _useInterval,
+              onChanged: (value) {
+                setState(() {
+                  _useInterval = value;
+                });
+              },
+            ),
+            Text('SRS Level: $_srsLevel'),
+            const SizedBox(height: 20),
+            ElevatedButton(
+              onPressed: _saveChanges,
+              child: const Text('Save Changes'),
+            ),
+          ],
+        ),
+      ),
+    );
+  }
+}

lib/src/screens/custom_quiz_screen.dart

@@ -9,16 +9,23 @@ enum CustomQuizMode { japaneseToEnglish, englishToJapanese, listeningComprehensi
 class CustomQuizScreen extends StatefulWidget {
   final List<CustomKanjiItem> deck;
   final CustomQuizMode quizMode;
+  final Function(CustomKanjiItem) onCardReviewed;
+  final bool useKanji;
 
-  const CustomQuizScreen(
+  const CustomQuizScreen({
-      {super.key, required this.deck, required this.quizMode});
+    super.key,
+    required this.deck,
+    required this.quizMode,
+    required this.onCardReviewed,
+    required this.useKanji,
+  });
 
   @override
   State<CustomQuizScreen> createState() => CustomQuizScreenState();
 }
 
 class CustomQuizScreenState extends State<CustomQuizScreen>
-    with TickerProviderStateMixin, AutomaticKeepAliveClientMixin {
+    with TickerProviderStateMixin {
   int _currentIndex = 0;
   List<CustomKanjiItem> _shuffledDeck = [];
   List<String> _options = [];
@@ -27,17 +34,15 @@ class CustomQuizScreenState extends State<CustomQuizScreen>
   late FlutterTts _flutterTts;
   late AnimationController _shakeController;
   late Animation<double> _shakeAnimation;
-  bool _useKanji = false;
-
-  @override
-  bool get wantKeepAlive => true;
 
   @override
   void initState() {
     super.initState();
     _shuffledDeck = widget.deck.toList()..shuffle();
     _initTts();
+    if (_shuffledDeck.isNotEmpty) {
       _generateOptions();
+    }
 
     _shakeController = AnimationController(
       duration: const Duration(milliseconds: 500),
@@ -51,6 +56,16 @@ class CustomQuizScreenState extends State<CustomQuizScreen>
     );
   }
 
+  @override
+  void didUpdateWidget(CustomQuizScreen oldWidget) {
+    super.didUpdateWidget(oldWidget);
+    if (widget.useKanji != oldWidget.useKanji) {
+      setState(() {
+        _generateOptions();
+      });
+    }
+  }
+
   void playAudio() {
     if (widget.quizMode == CustomQuizMode.listeningComprehension) {
       _speak(_shuffledDeck[_currentIndex].characters);
@@ -60,7 +75,7 @@ class CustomQuizScreenState extends State<CustomQuizScreen>
   void _initTts() async {
     _flutterTts = FlutterTts();
     await _flutterTts.setLanguage("ja-JP");
-    if (widget.quizMode == CustomQuizMode.listeningComprehension) {
+    if (_shuffledDeck.isNotEmpty && widget.quizMode == CustomQuizMode.listeningComprehension) {
       _speak(_shuffledDeck[_currentIndex].characters);
     }
   }
@@ -77,7 +92,7 @@ class CustomQuizScreenState extends State<CustomQuizScreen>
     if (widget.quizMode == CustomQuizMode.listeningComprehension || widget.quizMode == CustomQuizMode.japaneseToEnglish) {
       _options = [currentItem.meaning];
     } else {
-      _options = [_useKanji && currentItem.kanji != null ? currentItem.kanji! : currentItem.characters];
+      _options = [widget.useKanji && currentItem.kanji != null ? currentItem.kanji! : currentItem.characters];
     }
     final otherItems = widget.deck
         .where((item) => item.characters != currentItem.characters)
@@ -87,7 +102,7 @@ class CustomQuizScreenState extends State<CustomQuizScreen>
       if (widget.quizMode == CustomQuizMode.listeningComprehension || widget.quizMode == CustomQuizMode.japaneseToEnglish) {
         _options.add(otherItems[i].meaning);
       } else {
-        _options.add(_useKanji && otherItems[i].kanji != null ? otherItems[i].kanji! : otherItems[i].characters);
+        _options.add(widget.useKanji && otherItems[i].kanji != null ? otherItems[i].kanji! : otherItems[i].characters);
       }
     }
     _options.shuffle();
@@ -96,10 +111,22 @@ class CustomQuizScreenState extends State<CustomQuizScreen>
   void _checkAnswer(String answer) {
     final currentItem = _shuffledDeck[_currentIndex];
     final correctAnswer = (widget.quizMode == CustomQuizMode.englishToJapanese)
-        ? (_useKanji && currentItem.kanji != null ? currentItem.kanji! : currentItem.characters)
+        ? (widget.useKanji && currentItem.kanji != null ? currentItem.kanji! : currentItem.characters)
         : currentItem.meaning;
     final isCorrect = answer == correctAnswer;
 
+    if (currentItem.useInterval) {
+      if (isCorrect) {
+        currentItem.srsLevel++;
+        final interval = pow(2, currentItem.srsLevel).toInt();
+        currentItem.nextReview = DateTime.now().add(Duration(hours: interval));
+      } else {
+        currentItem.srsLevel = max(0, currentItem.srsLevel - 1);
+        currentItem.nextReview = DateTime.now().add(const Duration(hours: 1));
+      }
+      widget.onCardReviewed(currentItem);
+    }
+
     setState(() {
       _answered = true;
       _correct = isCorrect;
@@ -139,43 +166,18 @@ class CustomQuizScreenState extends State<CustomQuizScreen>
 
   @override
   Widget build(BuildContext context) {
-    super.build(context);
     if (_shuffledDeck.isEmpty) {
-      return Scaffold(
+      return const Center(
-        appBar: AppBar(),
+        child: Text('Review session complete!'),
-        body: const Center(
-          child: Text('No cards in the deck!'),
-        ),
       );
     }
 
     final currentItem = _shuffledDeck[_currentIndex];
     final question = (widget.quizMode == CustomQuizMode.englishToJapanese)
         ? currentItem.meaning
-        : (_useKanji && currentItem.kanji != null ? currentItem.kanji! : currentItem.characters);
+        : (widget.useKanji && currentItem.kanji != null ? currentItem.kanji! : currentItem.characters);
 
-    return Scaffold(
+    return Center(
-      appBar: AppBar(
-        title: const Text('Quiz'),
-        actions: [
-          if (widget.quizMode != CustomQuizMode.listeningComprehension)
-            Row(
-              children: [
-                const Text('Kanji'),
-                Switch(
-                  value: _useKanji,
-                  onChanged: (value) {
-                    setState(() {
-                      _useKanji = value;
-                      _generateOptions();
-                    });
-                  },
-                ),
-              ],
-            ),
-        ],
-      ),
-      body: Center(
       child: Column(
         mainAxisAlignment: MainAxisAlignment.center,
         children: [
@@ -223,7 +225,6 @@ class CustomQuizScreenState extends State<CustomQuizScreen>
             ),
         ],
       ),
-      ),
     );
   }
 }

lib/src/screens/custom_srs_screen.dart

@@ -15,6 +15,8 @@ class _CustomSrsScreenState extends State<CustomSrsScreen> with SingleTickerProv
   late TabController _tabController;
   final _deckRepository = CustomDeckRepository();
   List<CustomKanjiItem> _deck = [];
+  List<CustomKanjiItem> _reviewDeck = [];
+  bool _useKanji = false;
   final _quizScreenKeys = [
     GlobalKey<CustomQuizScreenState>(),
     GlobalKey<CustomQuizScreenState>(),
@@ -30,6 +32,7 @@ class _CustomSrsScreenState extends State<CustomSrsScreen> with SingleTickerProv
         final key = _quizScreenKeys[_tabController.index];
         key.currentState?.playAudio();
       }
+      setState(() {});
     });
     _loadDeck();
   }
@@ -42,16 +45,52 @@ class _CustomSrsScreenState extends State<CustomSrsScreen> with SingleTickerProv
 
   Future<void> _loadDeck() async {
     final deck = await _deckRepository.getCustomDeck();
+    final now = DateTime.now();
+    final reviewDeck = deck.where((item) {
+      if (!item.useInterval) {
+        return true;
+      }
+      return item.nextReview == null || item.nextReview!.isBefore(now);
+    }).toList();
+
     setState(() {
       _deck = deck;
+      _reviewDeck = reviewDeck;
     });
   }
 
+  Future<void> _updateCard(CustomKanjiItem item) async {
+    final index = _deck.indexWhere((element) => element.characters == item.characters);
+    if (index != -1) {
+      setState(() {
+        _deck[index] = item;
+        _reviewDeck.removeWhere((element) => element.characters == item.characters);
+      });
+      await _deckRepository.saveDeck(_deck);
+    }
+  }
+
   @override
   Widget build(BuildContext context) {
     return Scaffold(
       appBar: AppBar(
         title: const Text('Custom SRS'),
+        actions: [
+          if (_tabController.index != 2)
+            Row(
+              children: [
+                const Text('Kanji'),
+                Switch(
+                  value: _useKanji,
+                  onChanged: (value) {
+                    setState(() {
+                      _useKanji = value;
+                    });
+                  },
+                ),
+              ],
+            ),
+        ],
         bottom: TabBar(
           controller: _tabController,
           tabs: const [
@@ -62,13 +101,33 @@ class _CustomSrsScreenState extends State<CustomSrsScreen> with SingleTickerProv
         ),
       ),
       body: _deck.isEmpty
-          ? const Center(child: CircularProgressIndicator())
+          ? const Center(child: Text('Add cards to start quizzing!'))
+          : _reviewDeck.isEmpty
+              ? const Center(child: Text('No cards due for review.'))
               : TabBarView(
               controller: _tabController,
               children: [
-                CustomQuizScreen(key: _quizScreenKeys[0], deck: _deck, quizMode: CustomQuizMode.japaneseToEnglish),
+                CustomQuizScreen(
-                CustomQuizScreen(key: _quizScreenKeys[1], deck: _deck, quizMode: CustomQuizMode.englishToJapanese),
+                  key: _quizScreenKeys[0],
-                CustomQuizScreen(key: _quizScreenKeys[2], deck: _deck, quizMode: CustomQuizMode.listeningComprehension),
+                  deck: _reviewDeck,
+                  quizMode: CustomQuizMode.japaneseToEnglish,
+                  onCardReviewed: _updateCard,
+                  useKanji: _useKanji,
+                ),
+                CustomQuizScreen(
+                  key: _quizScreenKeys[1],
+                  deck: _reviewDeck,
+                  quizMode: CustomQuizMode.englishToJapanese,
+                  onCardReviewed: _updateCard,
+                  useKanji: _useKanji,
+                ),
+                CustomQuizScreen(
+                  key: _quizScreenKeys[2],
+                  deck: _reviewDeck,
+                  quizMode: CustomQuizMode.listeningComprehension,
+                  onCardReviewed: _updateCard,
+                  useKanji: _useKanji,
+                ),
               ],
             ),
       floatingActionButton: FloatingActionButton(

lib/src/screens/start_screen.dart

@@ -24,97 +24,111 @@ class StartScreen extends StatelessWidget {
           ),
         ],
       ),
-      body: SafeArea(
+      body: Container(
-        child: Center(
+        decoration: BoxDecoration(
-          child: Padding(
+          gradient: LinearGradient(
-            padding: const EdgeInsets.all(32),
+            colors: [
-            child: Column(
+              const Color(0xFF121212),
-              mainAxisAlignment: MainAxisAlignment.center,
+              Colors.grey[900]!,
+            ],
+            begin: Alignment.topLeft,
+            end: Alignment.bottomRight,
+          ),
+        ),
+        child: GridView.count(
+          crossAxisCount: 2,
+          padding: const EdgeInsets.all(16),
+          crossAxisSpacing: 16,
+          mainAxisSpacing: 16,
+          childAspectRatio: 0.8,
           children: [
-                ElevatedButton(
+            _buildModeCard(
-                  onPressed: () {
+              context,
+              title: 'Kanji Quiz',
+              icon: Icons.extension,
+              description: 'Test your knowledge of kanji characters.',
+              onTap: () {
                 Navigator.of(context).push(
                   MaterialPageRoute(builder: (_) => const HomeScreen()),
                 );
               },
-                  style: ElevatedButton.styleFrom(
-                    backgroundColor: Colors.blueAccent,
-                    foregroundColor: Colors.white,
-                    padding:
-                        const EdgeInsets.symmetric(horizontal: 32, vertical: 16),
-                    shape: RoundedRectangleBorder(
-                        borderRadius: BorderRadius.circular(12)),
             ),
-                  child: const Text(
+            _buildModeCard(
-                    'Kanji Quiz',
+              context,
-                    style: TextStyle(fontSize: 18),
+              title: 'Vocabulary Quiz',
-                  ),
+              icon: Icons.school,
-                ),
+              description: 'Practice vocabulary from your WaniKani deck.',
-                const SizedBox(height: 16),
+              onTap: () {
-                ElevatedButton(
-                  onPressed: () {
                 Navigator.of(context).push(
                   MaterialPageRoute(builder: (_) => const VocabScreen()),
                 );
               },
-                  style: ElevatedButton.styleFrom(
-                    backgroundColor: Colors.blueAccent,
-                    foregroundColor: Colors.white,
-                    padding:
-                        const EdgeInsets.symmetric(horizontal: 32, vertical: 16),
-                    shape: RoundedRectangleBorder(
-                        borderRadius: BorderRadius.circular(12)),
             ),
-                  child: const Text(
+            _buildModeCard(
-                    'Vocabulary Quiz',
+              context,
-                    style: TextStyle(fontSize: 18),
+              title: 'Browse Items',
-                  ),
+              icon: Icons.grid_view,
-                ),
+              description: 'Look through your kanji and vocabulary decks.',
-                const SizedBox(height: 16),
+              onTap: () {
-                ElevatedButton(
-                  onPressed: () {
                 Navigator.of(context).push(
                   MaterialPageRoute(builder: (_) => const BrowseScreen()),
                 );
               },
-                  style: ElevatedButton.styleFrom(
-                    backgroundColor: Colors.deepPurpleAccent,
-                    foregroundColor: Colors.white,
-                    padding:
-                        const EdgeInsets.symmetric(horizontal: 32, vertical: 16),
-                    shape: RoundedRectangleBorder(
-                        borderRadius: BorderRadius.circular(12)),
             ),
-                  child: const Text(
+            _buildModeCard(
-                    'Browse Items',
+              context,
-                    style: TextStyle(fontSize: 18),
+              title: 'Custom SRS',
-                  ),
+              icon: Icons.create,
-                ),
+              description: 'Create and study your own custom flashcards.',
-                const SizedBox(height: 16),
+              onTap: () {
-                ElevatedButton(
-                  onPressed: () {
                 Navigator.of(context).push(
                   MaterialPageRoute(builder: (_) => const CustomSrsScreen()),
                 );
               },
-                  style: ElevatedButton.styleFrom(
-                    backgroundColor: Colors.greenAccent,
-                    foregroundColor: Colors.black,
-                    padding:
-                        const EdgeInsets.symmetric(horizontal: 32, vertical: 16),
-                    shape: RoundedRectangleBorder(
-                        borderRadius: BorderRadius.circular(12)),
             ),
-                  child: const Text(
+          ],
-                    'Custom SRS',
+        ),
-                    style: TextStyle(fontSize: 18),
+      ),
+    );
+  }
+
+  Widget _buildModeCard(BuildContext context, {
+    required String title,
+    required IconData icon,
+    required String description,
+    required VoidCallback onTap,
+  }) {
+    return Card(
+      elevation: 4,
+      shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(12)),
+      child: InkWell(
+        onTap: onTap,
+        borderRadius: BorderRadius.circular(12),
+        child: Padding(
+          padding: const EdgeInsets.all(16.0),
+          child: Column(
+            mainAxisAlignment: MainAxisAlignment.center,
+            children: [
+              Icon(icon, size: 48, color: Theme.of(context).colorScheme.primary),
+              const SizedBox(height: 16),
+              Text(
+                title,
+                style: const TextStyle(fontSize: 18, fontWeight: FontWeight.bold),
+                textAlign: TextAlign.center,
+              ),
+              const SizedBox(height: 8),
+              Expanded(
+                child: Text(
+                  description,
+                  style: const TextStyle(fontSize: 12, color: Colors.grey),
+                  textAlign: TextAlign.center,
+                  softWrap: true,
                 ),
               ),
             ],
           ),
         ),
       ),
-      ),
     );
   }
 }

lib/src/services/custom_deck_repository.dart

@@ -19,10 +19,25 @@ class CustomDeckRepository {
   Future<void> addCard(CustomKanjiItem item) async {
     final deck = await getCustomDeck();
     deck.add(item);
-    await _saveDeck(deck);
+    await saveDeck(deck);
   }
 
-  Future<void> _saveDeck(List<CustomKanjiItem> deck) async {
+  Future<void> updateCard(CustomKanjiItem item) async {
+    final deck = await getCustomDeck();
+    final index = deck.indexWhere((element) => element.characters == item.characters);
+    if (index != -1) {
+      deck[index] = item;
+      await saveDeck(deck);
+    }
+  }
+
+  Future<void> deleteCard(CustomKanjiItem item) async {
+    final deck = await getCustomDeck();
+    deck.removeWhere((element) => element.characters == item.characters);
+    await saveDeck(deck);
+  }
+
+  Future<void> saveDeck(List<CustomKanjiItem> deck) async {
     final prefs = await SharedPreferences.getInstance();
     final jsonList = deck.map((item) => item.toJson()).toList();
     await prefs.setString(_key, json.encode(jsonList));

lib/src/services/deck_repository.dart

@@ -6,6 +6,8 @@ import 'package:sqflite/sqflite.dart';
 import '../models/kanji_item.dart';
 import '../api/wk_client.dart';
 
+import 'package:flutter_dotenv/flutter_dotenv.dart';
+
 class DeckRepository {
   Database? _db;
   String? _apiKey;
@@ -98,6 +100,12 @@ class DeckRepository {
   }
 
   Future<String?> loadApiKey() async {
+    final envApiKey = dotenv.env['WANIKANI_API_KEY'];
+    if (envApiKey != null && envApiKey.isNotEmpty) {
+      _apiKey = envApiKey;
+      return _apiKey;
+    }
+
     final db = await _openDb();
     final rows = await db.query(
       'settings',

pubspec.lock

@@ -302,6 +302,14 @@ packages:
     description: flutter
     source: sdk
     version: "0.0.0"
+  flutter_dotenv:
+    dependency: "direct main"
+    description:
+      name: flutter_dotenv
+      sha256: b7c7be5cd9f6ef7a78429cabd2774d3c4af50e79cb2b7593e3d5d763ef95c61b
+      url: "https://pub.dev"
+    source: hosted
+    version: "5.2.1"
   flutter_launcher_icons:
     dependency: "direct dev"
     description:

pubspec.yaml

@@ -16,6 +16,7 @@ dependencies:
   http: ^1.5.0
   kana_kit: ^2.1.1
   flutter_tts: ^3.8.5
+  flutter_dotenv: ^5.1.0
 
 dev_dependencies:
   flutter_test:
@@ -34,3 +35,4 @@ flutter:
   uses-material-design: true
   assets:
     - assets/sfx/confirm.mp3
+    - .env