import 'dart:convert';
import 'package:dio/dio.dart';
import '../models/recipe.dart';
import '../storage/secure_storage_service.dart';

class ApiException implements Exception {
  final String message;
  final int? statusCode;
  ApiException(this.message, [this.statusCode]);

  @override
  String toString() => message;
}

class ApiClient {
  final SecureStorageService _storage;
  final Dio _dio;

  ApiClient(this._storage)
      : _dio = Dio(
          BaseOptions(
            connectTimeout: const Duration(seconds: 15),
            receiveTimeout: const Duration(seconds: 45),
            headers: {'Accept': 'application/json'},
          ),
        ) {
    // Interceptor to auto-inject Bearer mobile token and base URL
    _dio.interceptors.add(
      InterceptorsWrapper(
        onRequest: (options, handler) async {
          final serverUrl = await _storage.getServerUrl();
          final token = await _storage.getToken();

          if (serverUrl != null && !options.path.startsWith('http')) {
            options.baseUrl = serverUrl;
          }

          if (token != null && token.isNotEmpty) {
            options.headers['Authorization'] = 'Bearer $token';
          }

          return handler.next(options);
        },
        onError: (DioException e, handler) {
          String message = 'Network communication error.';
          if (e.response != null) {
            final data = e.response?.data;
            if (data is Map && data['error'] != null) {
              message = data['error'].toString();
            } else if (e.response?.statusCode == 401) {
              message = 'Session expired or invalid. Please log in again.';
            } else {
              message = 'Server returned HTTP ${e.response?.statusCode}.';
            }
          } else if (e.type == DioExceptionType.connectionTimeout) {
            message = 'Connection timed out. Please check your internet or server URL.';
          } else if (e.type == DioExceptionType.connectionError) {
            message = 'Could not connect to ForkFolio server. Check domain or VPN status.';
          }
          return handler.reject(
            DioException(
              requestOptions: e.requestOptions,
              error: ApiException(message, e.response?.statusCode),
              response: e.response,
              type: e.type,
            ),
          );
        },
      ),
    );
  }

  // 1. Mobile App Login
  Future<Map<String, dynamic>> login({
    required String serverUrl,
    required String username,
    required String password,
    required String deviceName,
  }) async {
    final cleanUrl = serverUrl.trim().replaceAll(RegExp(r'/+$'), '');
    try {
      final response = await _dio.post(
        '$cleanUrl/api/auth/mobile-login',
        data: {
          'username': username.trim(),
          'password': password,
          'deviceName': deviceName.trim(),
        },
      );

      final data = response.data as Map<String, dynamic>;
      final token = data['token'] as String;
      final expiresAt = data['expiresAt'] as String;
      final user = data['user'] as Map<String, dynamic>;

      await _storage.saveSession(
        serverUrl: cleanUrl,
        token: token,
        user: user,
        expiresAt: expiresAt,
      );

      return data;
    } on DioException catch (e) {
      final err = e.error;
      if (err is ApiException) throw err;
      throw ApiException(e.message ?? 'Login failed');
    }
  }

  // 2. Fetch User Recipes
  Future<List<Recipe>> fetchRecipes() async {
    try {
      final response = await _dio.get('/api/recipes');
      final list = response.data as List<dynamic>;
      return list.map((item) => Recipe.fromJson(item as Map<String, dynamic>)).toList();
    } on DioException catch (e) {
      final err = e.error;
      if (err is ApiException) throw err;
      throw ApiException(e.message ?? 'Failed to load recipes');
    }
  }

  // 3. Scrape Recipe from Link or Social Media Caption
  Future<Map<String, dynamic>> scrapeRecipe({
    String? url,
    String? rawCaption,
  }) async {
    try {
      final response = await _dio.post(
        '/api/scrape',
        data: {
          if (url != null && url.isNotEmpty) 'url': url.trim(),
          if (rawCaption != null && rawCaption.isNotEmpty) 'rawCaption': rawCaption.trim(),
        },
      );
      return response.data as Map<String, dynamic>;
    } on DioException catch (e) {
      final err = e.error;
      if (err is ApiException) throw err;
      throw ApiException(e.message ?? 'Failed to scrape recipe details');
    }
  }

  // 4. Scan Recipe Photo via Gemini Multimodal Vision Endpoint
  Future<Map<String, dynamic>> scanRecipePhoto({
    required String imageBase64,
    String mimeType = 'image/jpeg',
  }) async {
    try {
      final response = await _dio.post(
        '/api/recipes/scan-photo',
        data: {
          'imageBase64': imageBase64,
          'mimeType': mimeType,
        },
        options: Options(receiveTimeout: const Duration(seconds: 90)),
      );
      return response.data as Map<String, dynamic>;
    } on DioException catch (e) {
      final err = e.error;
      if (err is ApiException) throw err;
      throw ApiException(e.message ?? 'Photo recipe extraction failed');
    }
  }

  // 5. Save or Update Recipe
  Future<Recipe> saveRecipe(Recipe recipe) async {
    try {
      Response response;
      if (recipe.id != null && recipe.id!.isNotEmpty) {
        response = await _dio.put('/api/recipes/${recipe.id}', data: recipe.toJson());
      } else {
        response = await _dio.post('/api/recipes', data: recipe.toJson());
      }
      return Recipe.fromJson(response.data as Map<String, dynamic>);
    } on DioException catch (e) {
      final err = e.error;
      if (err is ApiException) throw err;
      throw ApiException(e.message ?? 'Failed to save recipe');
    }
  }

  // 6. Delete Recipe
  Future<void> deleteRecipe(String id) async {
    try {
      await _dio.delete('/api/recipes/$id');
    } on DioException catch (e) {
      final err = e.error;
      if (err is ApiException) throw err;
      throw ApiException(e.message ?? 'Failed to delete recipe');
    }
  }

  // 7. Logout
  Future<void> logout() async {
    try {
      await _dio.post('/api/auth/logout');
    } catch (_) {
      // Continue clearing local storage even if network request fails
    } finally {
      await _storage.clearSession();
    }
  }
}