import 'package:flutter/material.dart';
import '../models/custom_kanji_item.dart';
import '../services/custom_deck_repository.dart';
import 'custom_quiz_screen.dart';

class CustomSrsScreen extends StatefulWidget {
  const CustomSrsScreen({super.key});

  @override
  State<CustomSrsScreen> createState() => _CustomSrsScreenState();
}

class _CustomSrsScreenState extends State<CustomSrsScreen> with SingleTickerProviderStateMixin {
  late TabController _tabController;
  final _deckRepository = CustomDeckRepository();
  List<CustomKanjiItem> _deck = [];
  bool _useKanji = false;
  final _quizScreenKeys = [
    GlobalKey<CustomQuizScreenState>(),
    GlobalKey<CustomQuizScreenState>(),
    GlobalKey<CustomQuizScreenState>(),
  ];

  @override
  void initState() {
    super.initState();
    _tabController = TabController(length: 3, vsync: this);
    _tabController.addListener(() {
      if (_tabController.indexIsChanging) {
        final key = _quizScreenKeys[_tabController.index];
        key.currentState?.playAudio();
      }
      setState(() {});
    });
    _loadDeck();
  }

  @override
  void dispose() {
    _tabController.dispose();
    super.dispose();
  }

  Future<void> _loadDeck() async {
    final deck = await _deckRepository.getCustomDeck();
    setState(() {
      _deck = deck;
    });
  }

  Future<void> _updateCard(CustomKanjiItem item) async {
    final index = _deck.indexWhere((element) => element.characters == item.characters);
    if (index != -1) {
      setState(() {
        _deck[index] = item;
      });
      await _deckRepository.saveDeck(_deck);
    }
  }

  @override
  Widget build(BuildContext context) {
    final now = DateTime.now();
    final jpnToEngReviewDeck = _deck.where((item) {
      if (!item.useInterval) return true;
      return item.srsData.japaneseToEnglishNextReview == null ||
          item.srsData.japaneseToEnglishNextReview!.isBefore(now);
    }).toList();

    final engToJpnReviewDeck = _deck.where((item) {
      if (!item.useInterval) return true;
      return item.srsData.englishToJapaneseNextReview == null ||
          item.srsData.englishToJapaneseNextReview!.isBefore(now);
    }).toList();

    final listeningReviewDeck = _deck.where((item) {
      if (!item.useInterval) return true;
      return item.srsData.listeningComprehensionNextReview == null ||
          item.srsData.listeningComprehensionNextReview!.isBefore(now);
    }).toList();

    final allDecksEmpty = jpnToEngReviewDeck.isEmpty &&
        engToJpnReviewDeck.isEmpty &&
        listeningReviewDeck.isEmpty;

    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 [
            Tab(text: 'Jpn→Eng'),
            Tab(text: 'Eng→Jpn'),
            Tab(text: 'Listening'),
          ],
        ),
      ),
      body: _deck.isEmpty
          ? const Center(child: Text('Add cards to start quizzing!'))
          : allDecksEmpty
              ? const Center(child: Text('No cards due for review.'))
              : TabBarView(
              controller: _tabController,
              children: [
                CustomQuizScreen(
                  key: _quizScreenKeys[0],
                  deck: jpnToEngReviewDeck,
                  quizMode: CustomQuizMode.japaneseToEnglish,
                  onCardReviewed: _updateCard,
                  useKanji: _useKanji,
                  isActive: _tabController.index == 0,
                ),
                CustomQuizScreen(
                  key: _quizScreenKeys[1],
                  deck: engToJpnReviewDeck,
                  quizMode: CustomQuizMode.englishToJapanese,
                  onCardReviewed: _updateCard,
                  useKanji: _useKanji,
                  isActive: _tabController.index == 1,
                ),
                CustomQuizScreen(
                  key: _quizScreenKeys[2],
                  deck: listeningReviewDeck,
                  quizMode: CustomQuizMode.listeningComprehension,
                  onCardReviewed: _updateCard,
                  useKanji: _useKanji,
                  isActive: _tabController.index == 2,
                ),
              ],
            ),
    );
  }
}