import 'package:flutter_test/flutter_test.dart';
import 'package:lunchpick/domain/usecases/recommendation_engine.dart';
import 'package:lunchpick/domain/entities/restaurant.dart';
import 'package:lunchpick/domain/entities/visit_record.dart';
import 'package:lunchpick/domain/entities/user_settings.dart';
import 'package:uuid/uuid.dart';

void main() {
  late RecommendationEngine engine;
  late List<Restaurant> testRestaurants;
  late List<VisitRecord> testVisitRecords;
  
  setUp(() {
    engine = RecommendationEngine();
    
    // 테스트용 맛집 데이터 생성
    testRestaurants = [
      Restaurant(
        id: '1',
        name: '가까운 한식당',
        category: '한식',
        subCategory: '백반',
        roadAddress: '서울 중구 세종대로 110',
        jibunAddress: '서울 중구 태평로1가 31',
        latitude: 37.5666,
        longitude: 126.9784,
        source: DataSource.USER_INPUT,
        createdAt: DateTime.now(),
        updatedAt: DateTime.now(),
        visitCount: 0,
      ),
      Restaurant(
        id: '2',
        name: '먼 중식당',
        category: '중식',
        subCategory: '짜장면',
        roadAddress: '서울 강남구 테헤란로 123',
        jibunAddress: '서울 강남구 역삼동 123',
        latitude: 37.5012,
        longitude: 127.0396,
        source: DataSource.USER_INPUT,
        createdAt: DateTime.now(),
        updatedAt: DateTime.now(),
        visitCount: 0,
      ),
      Restaurant(
        id: '3',
        name: '최근 방문한 일식당',
        category: '일식',
        subCategory: '스시',
        roadAddress: '서울 종로구 종로 123',
        jibunAddress: '서울 종로구 종로1가 123',
        latitude: 37.5702,
        longitude: 126.9842,
        source: DataSource.USER_INPUT,
        createdAt: DateTime.now(),
        updatedAt: DateTime.now(),
        visitCount: 1,
      ),
    ];
    
    // 테스트용 방문 기록 생성
    testVisitRecords = [
      VisitRecord(
        id: const Uuid().v4(),
        restaurantId: '3',
        visitDate: DateTime.now().subtract(const Duration(days: 2)),
        isConfirmed: true,
        createdAt: DateTime.now(),
      ),
    ];
  });

  group('RecommendationEngine', () {
    test('거리 필터링이 정상 작동해야 함', () async {
      final config = RecommendationConfig(
        userLatitude: 37.5665,
        userLongitude: 126.9780,
        maxDistance: 1.0, // 1km
        selectedCategories: [],
        userSettings: UserSettings(),
      );

      final result = await engine.generateRecommendation(
        allRestaurants: testRestaurants,
        recentVisits: [],
        config: config,
      );

      // 1km 이내의 맛집만 추천되어야 함
      expect(result, isNotNull);
      expect(result!.id, isIn(['1', '3'])); // 가까운 한식당과 일식당만
      expect(result.id, isNot('2')); // 먼 중식당은 제외
    });

    test('재방문 방지가 정상 작동해야 함', () async {
      final settings = UserSettings();
      final updatedSettings = settings.copyWith(revisitPreventionDays: 7);
      
      final config = RecommendationConfig(
        userLatitude: 37.5665,
        userLongitude: 126.9780,
        maxDistance: 10.0, // 10km
        selectedCategories: [],
        userSettings: updatedSettings,
      );

      final result = await engine.generateRecommendation(
        allRestaurants: testRestaurants,
        recentVisits: testVisitRecords,
        config: config,
      );

      // 최근 방문한 일식당은 제외되어야 함
      expect(result, isNotNull);
      expect(result!.id, isNot('3'));
    });

    test('카테고리 필터링이 정상 작동해야 함', () async {
      final config = RecommendationConfig(
        userLatitude: 37.5665,
        userLongitude: 126.9780,
        maxDistance: 100.0, // 100km
        selectedCategories: ['한식'],
        userSettings: UserSettings(),
      );

      final result = await engine.generateRecommendation(
        allRestaurants: testRestaurants,
        recentVisits: [],
        config: config,
      );

      // 한식만 추천되어야 함
      expect(result, isNotNull);
      expect(result!.category, '한식');
    });

    test('모든 조건을 만족하는 맛집이 없으면 null을 반환해야 함', () async {
      final config = RecommendationConfig(
        userLatitude: 37.5665,
        userLongitude: 126.9780,
        maxDistance: 0.1, // 100m - 너무 가까움
        selectedCategories: [],
        userSettings: UserSettings(),
      );

      final result = await engine.generateRecommendation(
        allRestaurants: testRestaurants,
        recentVisits: [],
        config: config,
      );

      expect(result, isNull);
    });

    test('가중치 시스템이 정상 작동해야 함', () async {
      // 한식에 높은 가중치 부여
      final settings = UserSettings();
      final updatedSettings = settings.copyWith(
        categoryWeights: {
          '한식': 2.0,
          '중식': 0.5,
          '일식': 1.0,
        },
      );
      
      final config = RecommendationConfig(
        userLatitude: 37.5665,
        userLongitude: 126.9780,
        maxDistance: 100.0,
        selectedCategories: [],
        userSettings: updatedSettings,
      );

      // 여러 번 실행하여 한식이 더 자주 추천되는지 확인
      final results = <String, int>{};
      for (int i = 0; i < 100; i++) {
        final result = await engine.generateRecommendation(
          allRestaurants: testRestaurants,
          recentVisits: [],
          config: config,
        );
        if (result != null) {
          results[result.category] = (results[result.category] ?? 0) + 1;
        }
      }

      // 한식이 다른 카테고리보다 더 많이 추천되어야 함
      expect(results['한식'] ?? 0, greaterThan(results['중식'] ?? 0));
    });
  });
}