import 'dart:convert';
import 'dart:io';

import 'package:flutter/foundation.dart';
import 'package:flutter/services.dart' show rootBundle;

import '../models/lenormand_pairs.dart';

class LenormandPairsRepository {
  static final LenormandPairsRepository _instance =
      LenormandPairsRepository._internal();
  factory LenormandPairsRepository() => _instance;
  LenormandPairsRepository._internal();

  final Map<int, LenormandCardEntry> _byN = {};
  List<LenormandTriad> _triads = const [];
  List<LenormandExtra> _extras = const [];
  bool _loaded = false;

  bool get isLoaded => _loaded;
  List<LenormandCardEntry> get cards =>
      List.unmodifiable(_byN.values.toList()..sort((a, b) => a.n.compareTo(b.n)));
  List<LenormandTriad> get triads => List.unmodifiable(_triads);
  List<LenormandExtra> get extras => List.unmodifiable(_extras);

  LenormandCardEntry? byNumber(int n) => _byN[n];

  LenormandCardEntry? byStationId(String id) {
    if (id.startsWith('card_')) {
      final n = int.tryParse(id.substring(5));
      if (n != null) return _byN[n];
    }
    return null;
  }

  Future<void> init() async {
    if (_loaded && _byN.isNotEmpty) return;
    Map<String, dynamic>? decoded;
    final cwd = Directory.current.path;
    final candidates = <String>{
      'assets/data/lenormand_pairs.json',
      '../assets/data/lenormand_pairs.json',
      '$cwd/assets/data/lenormand_pairs.json',
      '$cwd/../assets/data/lenormand_pairs.json',
    };
    for (final path in candidates) {
      try {
        final file = File(path);
        if (file.existsSync()) {
          decoded = json.decode(file.readAsStringSync()) as Map<String, dynamic>;
          break;
        }
      } catch (e) {
        debugPrint('lenormand_pairs.json skip $path: $e');
      }
    }
    if (decoded == null) {
      try {
        final jsonStr = await rootBundle.loadString('assets/data/lenormand_pairs.json');
        decoded = json.decode(jsonStr) as Map<String, dynamic>;
      } catch (e) {
        debugPrint('Could not load lenormand_pairs.json: $e');
      }
    }
    if (decoded == null) {
      _loaded = true;
      return;
    }
    _byN.clear();
    for (final raw in (decoded['cards'] as List? ?? const [])) {
      if (raw is! Map<String, dynamic>) continue;
      final card = LenormandCardEntry.fromMap(raw);
      _byN[card.n] = card;
    }
    _triads = (decoded['triads'] as List? ?? const [])
        .whereType<Map<String, dynamic>>()
        .map(LenormandTriad.fromMap)
        .toList();
    _extras = (decoded['extras'] as List? ?? const [])
        .whereType<Map<String, dynamic>>()
        .map(LenormandExtra.fromMap)
        .toList();
    _loaded = true;
  }
}