CoffeeAtHome/lib/services/statistics_service.dart

import '../models/bean.dart';
import '../models/machine.dart';
import '../models/recipe.dart';
import '../models/journal_entry.dart';
import '../models/drink.dart';

class CoffeeStatistics {
  final int totalBeans;
  final int totalMachines;
  final int totalRecipes;
  final int totalJournalEntries;
  final int totalDrinks;
  final double averageRating;
  final int preferredBeans;
  final String mostUsedRoastLevel;
  final List<Map<String, dynamic>> coffeeConsumptionTrend;
  final List<Drink> topRatedDrinks;
  final List<Map<String, dynamic>> recentActivity;
  final Map<String, dynamic> monthlyStats;

  CoffeeStatistics({
    required this.totalBeans,
    required this.totalMachines,
    required this.totalRecipes,
    required this.totalJournalEntries,
    required this.totalDrinks,
    required this.averageRating,
    required this.preferredBeans,
    required this.mostUsedRoastLevel,
    required this.coffeeConsumptionTrend,
    required this.topRatedDrinks,
    required this.recentActivity,
    required this.monthlyStats,
  });
}

class StatisticsService {
  static Future<CoffeeStatistics> getStatistics(
    List<Bean> beans,
    List<Machine> machines,
    List<Recipe> recipes,
    List<JournalEntry> journalEntries,
    List<Drink> drinks,
  ) async {
    try {
      // Calculate average rating
      final averageRating = drinks.isNotEmpty
          ? drinks.fold(0.0, (sum, drink) => sum + drink.rating) / drinks.length
          : 0.0;

      // Find most used roast level
      final roastLevelCounts = <String, int>{};
      for (final bean in beans) {
        roastLevelCounts[bean.roastLevel.toString().split('.').last] =
            (roastLevelCounts[bean.roastLevel.toString().split('.').last] ??
                0) +
            1;
      }

      final mostUsedRoastLevel =
          roastLevelCounts.entries
              .fold<MapEntry<String, int>?>(
                null,
                (max, entry) =>
                    max == null || entry.value > max.value ? entry : max,
              )
              ?.key ??
          'MEDIUM';

      // Calculate coffee consumption trend (last 6 months)
      final coffeeConsumptionTrend = _calculateConsumptionTrend(journalEntries);

      // Get top rated drinks
      final topRatedDrinks = List<Drink>.from(drinks)
        ..sort((a, b) => b.rating.compareTo(a.rating))
        ..take(5);

      // Recent activity
      final recentActivity = _getRecentActivity(
        beans,
        machines,
        recipes,
        journalEntries,
        drinks,
      );

      // Monthly stats
      final monthlyStats = _calculateMonthlyStats(journalEntries);

      return CoffeeStatistics(
        totalBeans: beans.length,
        totalMachines: machines.length,
        totalRecipes: recipes.length,
        totalJournalEntries: journalEntries.length,
        totalDrinks: drinks.length,
        averageRating: (averageRating * 10).round() / 10,
        preferredBeans: beans.where((bean) => bean.preferred).length,
        mostUsedRoastLevel: mostUsedRoastLevel,
        coffeeConsumptionTrend: coffeeConsumptionTrend,
        topRatedDrinks: topRatedDrinks,
        recentActivity: recentActivity,
        monthlyStats: monthlyStats,
      );
    } catch (error) {
      throw Exception('Error calculating statistics: $error');
    }
  }

  static List<Map<String, dynamic>> _calculateConsumptionTrend(
    List<JournalEntry> journalEntries,
  ) {
    final now = DateTime.now();
    final months = <Map<String, dynamic>>[];

    for (int i = 5; i >= 0; i--) {
      final date = DateTime(now.year, now.month - i, 1);
      final monthName = _getMonthName(date);

      final count = journalEntries.where((entry) {
        final entryDate = entry.date;
        return entryDate.month == date.month && entryDate.year == date.year;
      }).length;

      months.add({'month': monthName, 'count': count});
    }

    return months;
  }

  static List<Map<String, dynamic>> _getRecentActivity(
    List<Bean> beans,
    List<Machine> machines,
    List<Recipe> recipes,
    List<JournalEntry> journalEntries,
    List<Drink> drinks,
  ) {
    final activities = <Map<String, dynamic>>[];

    // Add recent journal entries
    for (final entry in journalEntries.take(5)) {
      activities.add({
        'date': entry.date,
        'type': 'Journal',
        'description': 'Enjoyed ${entry.drink.name}',
      });
    }

    // Add recent beans
    for (final bean in beans.take(3)) {
      activities.add({
        'date': bean.roastedDate,
        'type': 'Bean',
        'description':
            'Added ${bean.name} from ${bean.originCountry ?? 'Unknown'}',
      });
    }

    activities.sort(
      (a, b) => (b['date'] as DateTime).compareTo(a['date'] as DateTime),
    );
    return activities.take(10).toList();
  }

  static Map<String, dynamic> _calculateMonthlyStats(
    List<JournalEntry> journalEntries,
  ) {
    final now = DateTime.now();
    final currentMonth = now.month;
    final currentYear = now.year;

    final currentMonthCount = journalEntries.where((entry) {
      return entry.date.month == currentMonth && entry.date.year == currentYear;
    }).length;

    final lastMonth = currentMonth == 1 ? 12 : currentMonth - 1;
    final lastYear = currentMonth == 1 ? currentYear - 1 : currentYear;

    final lastMonthCount = journalEntries.where((entry) {
      return entry.date.month == lastMonth && entry.date.year == lastYear;
    }).length;

    final growth = lastMonthCount > 0
        ? (((currentMonthCount - lastMonthCount) / lastMonthCount) * 100)
              .round()
        : 0;

    return {
      'currentMonth': currentMonthCount,
      'lastMonth': lastMonthCount,
      'growth': growth,
    };
  }

  static String _getMonthName(DateTime date) {
    const months = [
      'Jan',
      'Feb',
      'Mar',
      'Apr',
      'May',
      'Jun',
      'Jul',
      'Aug',
      'Sep',
      'Oct',
      'Nov',
      'Dec',
    ];
    return '${months[date.month - 1]} ${date.year.toString().substring(2)}';
  }
}