import 'dart:convert';
import 'package:shared_preferences/shared_preferences.dart';
import '../models/custom_kanji_item.dart';

class CustomDeckRepository {
  static const _key = 'custom_deck';

  Future<List<CustomKanjiItem>> getCustomDeck() async {
    final prefs = await SharedPreferences.getInstance();
    final jsonString = prefs.getString(_key);
    if (jsonString != null) {
      final List<dynamic> jsonList = json.decode(jsonString);
      return jsonList.map((json) => CustomKanjiItem.fromJson(json)).toList();
    }
    return [];
  }

  Future<void> addCard(CustomKanjiItem item) async {
    final deck = await getCustomDeck();
    deck.add(item);
    await saveDeck(deck);
  }

  Future<void> updateCard(CustomKanjiItem item) async {
    await updateCards([item]);
  }

  Future<void> updateCards(List<CustomKanjiItem> itemsToUpdate) async {
    final deck = await getCustomDeck();
    for (var item in itemsToUpdate) {
      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));
  }
}