add custom srs

lib/src/screens/vocab_screen.dart

@@ -18,14 +18,14 @@ class VocabScreen extends StatefulWidget {
   State<VocabScreen> createState() => _VocabScreenState();
 }
 
-class _VocabScreenState extends State<VocabScreen> {
+class _VocabScreenState extends State<VocabScreen> with SingleTickerProviderStateMixin {
+  late TabController _tabController;
   List<VocabularyItem> _deck = [];
   bool _loading = false;
   String _status = 'Loading deck...';
   final DistractorGenerator _dg = DistractorGenerator();
   final _audioPlayer = AudioPlayer();
 
-  VocabQuizMode _mode = VocabQuizMode.vocabToEnglish;
   VocabularyItem? _current;
   List<String> _options = [];
   List<String> _correctAnswers = [];
@@ -33,14 +33,26 @@ class _VocabScreenState extends State<VocabScreen> {
   int _asked = 0;
   bool _playAudio = true;
   bool _playCorrectSound = true;
+  bool _apiKeyMissing = false;
 
   @override
   void initState() {
     super.initState();
+    _tabController = TabController(length: 3, vsync: this);
+    _tabController.addListener(() {
+      setState(() {});
+      _nextQuestion();
+    });
     _loadSettings();
     _loadDeck();
   }
 
+  @override
+  void dispose() {
+    _tabController.dispose();
+    super.dispose();
+  }
+
   Future<void> _loadSettings() async {
     final prefs = await SharedPreferences.getInstance();
     setState(() {
@@ -61,11 +73,10 @@ class _VocabScreenState extends State<VocabScreen> {
       final apiKey = repo.apiKey;
 
       if (apiKey == null || apiKey.isEmpty) {
-        if (mounted) {
-          Navigator.of(context).pushReplacement(
-            MaterialPageRoute(builder: (_) => const SettingsScreen()),
-          );
-        }
+        setState(() {
+          _apiKeyMissing = true;
+          _loading = false;
+        });
         return;
       }
 
@@ -82,6 +93,7 @@ class _VocabScreenState extends State<VocabScreen> {
         _deck = items;
         _status = 'Loaded ${items.length} vocabulary';
         _loading = false;
+        _apiKeyMissing = false;
       });
 
       _nextQuestion();
@@ -101,6 +113,19 @@ class _VocabScreenState extends State<VocabScreen> {
         .join(' ');
   }
 
+  VocabQuizMode get _mode {
+    switch (_tabController.index) {
+      case 0:
+        return VocabQuizMode.vocabToEnglish;
+      case 1:
+        return VocabQuizMode.englishToVocab;
+      case 2:
+        return VocabQuizMode.audioToEnglish;
+      default:
+        return VocabQuizMode.vocabToEnglish;
+    }
+  }
+
   void _nextQuestion() {
     if (_deck.isEmpty) return;
 
@@ -257,6 +282,30 @@ class _VocabScreenState extends State<VocabScreen> {
 
   @override
   Widget build(BuildContext context) {
+    if (_apiKeyMissing) {
+      return Scaffold(
+        appBar: AppBar(title: const Text('Vocabulary Quiz')),
+        body: Center(
+          child: Column(
+            mainAxisAlignment: MainAxisAlignment.center,
+            children: [
+              const Text('WaniKani API key is not set.', style: TextStyle(color: Colors.white)),
+              const SizedBox(height: 16),
+              ElevatedButton(
+                onPressed: () async {
+                  await Navigator.of(context).push(
+                    MaterialPageRoute(builder: (_) => const SettingsScreen()),
+                  );
+                  _loadDeck();
+                },
+                child: const Text('Go to Settings'),
+              ),
+            ],
+          ),
+        ),
+      );
+    }
+
     Widget promptWidget;
 
     if (_current == null) {
@@ -283,24 +332,18 @@ class _VocabScreenState extends State<VocabScreen> {
     }
 
     return Scaffold(
-      backgroundColor: const Color(0xFF121212),
       appBar: AppBar(
-        title: const Text('Hirameki SRS - Vocab'),
-        backgroundColor: const Color(0xFF1F1F1F),
-        foregroundColor: Colors.white,
-        elevation: 2,
-        actions: [
-          IconButton(
-            icon: const Icon(Icons.settings),
-            onPressed: () async {
-              await Navigator.of(context).push(
-                MaterialPageRoute(builder: (_) => const SettingsScreen()),
-              );
-              _loadSettings();
-            },
-          )
-        ],
+        title: const Text('Vocabulary Quiz'),
+        bottom: TabBar(
+          controller: _tabController,
+          tabs: const [
+            Tab(text: 'Vocab→English'),
+            Tab(text: 'English→Vocab'),
+            Tab(text: 'Listening'),
+          ],
+        ),
       ),
+      backgroundColor: const Color(0xFF121212),
       body: Padding(
         padding: const EdgeInsets.all(16.0),
         child: Column(
@@ -317,17 +360,6 @@ class _VocabScreenState extends State<VocabScreen> {
                   const CircularProgressIndicator(color: Colors.blueAccent),
               ],
             ),
-            const SizedBox(height: 12),
-            Wrap(
-              spacing: 6,
-              runSpacing: 4,
-              alignment: WrapAlignment.center,
-              children: [
-                _buildChoiceChip('Vocab→English', VocabQuizMode.vocabToEnglish),
-                _buildChoiceChip('English→Vocab', VocabQuizMode.englishToVocab),
-                _buildChoiceChip('Listening', VocabQuizMode.audioToEnglish),
-              ],
-            ),
             const SizedBox(height: 18),
             Expanded(
               flex: 3,
@@ -370,23 +402,5 @@ class _VocabScreenState extends State<VocabScreen> {
         ),
       ),
     );
-
   }
-
-  ChoiceChip _buildChoiceChip(String label, VocabQuizMode mode) {
-    final selected = _mode == mode;
-    return ChoiceChip(
-      label: Text(
-        label,
-        style: TextStyle(color: selected ? Colors.white : Colors.grey[400]),
-      ),
-      selected: selected,
-      onSelected: (v) {
-        setState(() => _mode = mode);
-        _nextQuestion();
-      },
-      selectedColor: Colors.blueAccent,
-      backgroundColor: const Color(0xFF1E1E1E),
-    );
-  }
-}
+}