import 'dart:convert';
import 'package:flutter/material.dart';
import 'package:shared_preferences/shared_preferences.dart';
import '../services/auth_service.dart';

class AuthProvider extends ChangeNotifier {
  AuthService? _service;

  bool _loading = false;
  bool get loading => _loading;

  bool initialized = false;

  String? _token;
  Map<String, dynamic>? _user;

  String? get token => _token;
  Map<String, dynamic>? get user => _user;

  bool get isLoggedIn => _token != null && _token!.isNotEmpty;

  // Inject context after provider initializes
  void initContext(BuildContext context) {
    _service = AuthService(context);
  }

  AuthProvider() {
    _loadFromPrefs();
  }

  // ---------------------- NEW FIX: SAFE INIT -----------------------
  Future<void> init() async {
    if (!initialized) {
      await _loadFromPrefs();
    }
  }

  // ---------------------- LOAD FROM PREFS -----------------------
  Future<void> _loadFromPrefs() async {
    final prefs = await SharedPreferences.getInstance();

    _token = prefs.getString('token');

    final userJson = prefs.getString('user');
    if (userJson != null) {
      try {
        _user = Map<String, dynamic>.from(jsonDecode(userJson));
      } catch (_) {
        _user = null;
      }
    }

    initialized = true;
    notifyListeners();
  }

  // -------------------------- LOGIN -----------------------------
  Future<Map<String, dynamic>> login(
      BuildContext context, String loginId, String password) async {
    _service ??= AuthService(context);

    _loading = true;
    notifyListeners();

    final res = await _service!.login(loginId, password);

    _loading = false;

    if (res['success'] == true) {
      final token = res['token']?.toString();
      final userMap =
      res['user'] is Map ? Map<String, dynamic>.from(res['user']) : null;

      if (token != null && userMap != null) {
        final prefs = await SharedPreferences.getInstance();
        await prefs.setString("saved_login_id", loginId);
        await prefs.setString("saved_password", password);

        await _saveSession(token, userMap);
      }
    }

    notifyListeners();
    return res;
  }

  // --------------------- SAVE SESSION ---------------------------
  Future<void> _saveSession(
      String token, Map<String, dynamic> userMap) async {
    final prefs = await SharedPreferences.getInstance();
    await prefs.setString('token', token);
    await prefs.setString('user', jsonEncode(userMap));

    _token = token;
    _user = userMap;
    notifyListeners();
  }

  // ----------------------- LOGOUT -------------------------------
  Future<void> logout(BuildContext context) async {
    _service ??= AuthService(context);

    try {
      await _service!.logout();
    } catch (_) {}

    final prefs = await SharedPreferences.getInstance();
    await prefs.remove('token');
    await prefs.remove('user');

    _token = null;
    _user = null;
    notifyListeners();
  }

  // -------------------- AUTO LOGIN ------------------------------
  Future<bool> autoLoginFromSavedCredentials(BuildContext context) async {
    final prefs = await SharedPreferences.getInstance();
    final loginId = prefs.getString('saved_login_id');
    final password = prefs.getString('saved_password');

    if (loginId == null || password == null) return false;

    final res = await login(context, loginId, password);
    return res['success'] == true;
  }

  // --------------------- REFRESH TOKEN --------------------------
  Future<bool> tryRefreshToken(BuildContext context) async {
    final prefs = await SharedPreferences.getInstance();
    final oldToken = prefs.getString('token');

    if (oldToken == null) return false;

    _service ??= AuthService(context);

    final res = await _service!.refreshToken(oldToken);

    if (res['success'] == true && res['token'] != null) {
      await prefs.setString('token', res['token']);
      _token = res['token'];
      notifyListeners();
      return true;
    }
    return false;
  }
}