import 'package:firebase_analytics/firebase_analytics.dart';
import 'package:flutter/foundation.dart';
import 'package:flutter/material.dart';

/// Firebase Analytics service for tracking user events across the app.
///
/// Usage:
/// ```dart
/// // Log add to cart event
/// AnalyticsService.logAddToCart(
///   productId: 'SKU123',
///   productName: 'Gạch men 60x60',
///   price: 150000,
///   quantity: 2,
/// );
/// ```
class AnalyticsService {
  AnalyticsService._();

  static final FirebaseAnalytics _analytics = FirebaseAnalytics.instance;

  /// Get the analytics instance for NavigatorObserver
  static FirebaseAnalytics get instance => _analytics;

  /// Get the observer for automatic screen tracking in GoRouter
  static FirebaseAnalyticsObserver get observer => FirebaseAnalyticsObserver(
        analytics: _analytics,
        nameExtractor: (settings) {
          // GoRouter uses the path as the route name
          final name = settings.name;
          if (name != null && name.isNotEmpty && name != '/') {
            return name;
          }
          return settings.name ?? '/';
        },
        routeFilter: (route) => route is PageRoute,
      );

  /// Log screen view manually
  static Future<void> logScreenView({
    required String screenName,
    String? screenClass,
  }) async {
    try {
      await _analytics.logScreenView(
        screenName: screenName,
        screenClass: screenClass,
      );
      debugPrint('📊 Analytics: screen_view - $screenName');
    } catch (e) {
      debugPrint('📊 Analytics error: $e');
    }
  }

  /// Log add to cart event
  ///
  /// [productId] - Product SKU or ID
  /// [productName] - Product display name
  /// [price] - Unit price in VND
  /// [quantity] - Quantity added
  /// [category] - Optional product category
  static Future<void> logAddToCart({
    required String productId,
    required String productName,
    required double price,
    required int quantity,
    String? brand,
  }) async {
    try {
      await _analytics.logAddToCart(
        currency: 'VND',
        value: price * quantity,
        items: [
          AnalyticsEventItem(
            itemId: productId,
            itemName: productName,
            price: price,
            quantity: quantity,
            itemBrand: brand,
          ),
        ],
      );
      debugPrint('📊 Analytics: add_to_cart - $productName x$quantity');
    } catch (e) {
      debugPrint('📊 Analytics error: $e');
    }
  }
}