// src/main/java/com/socialcommerce/chat/model/ChatMessage.java
@Document(collection = "chat_messages")
@Data
public class ChatMessage {
    @Id
    private String id;
    private String productId;
    private String senderId;
    private String content;
    private Instant timestamp = Instant.now();
}

// src/main/java/com/socialcommerce/chat/config/WebSocketConfig.java
@Configuration
@EnableWebSocketMessageBroker
public class WebSocketConfig implements WebSocketMessageBrokerConfigurer {
    @Override
    public void registerStompEndpoints(StompEndpointRegistry registry) {
        registry.addEndpoint("/live-chat").withSockJS();
    }
    
    @Override
    public void configureMessageBroker(MessageBrokerRegistry registry) {
        registry.enableSimpleBroker("/topic");
        registry.setApplicationDestinationPrefixes("/app");
    }
}

// src/main/java/com/socialcommerce/feed/model/FeedItem.java
@Document(collection = "feed_items")
@Data
@CompoundIndex(def = "{'userId': 1, 'score': -1}")
public class FeedItem {
    @Id
    private String id;
    private String userId;
    private String contentUrl;
    private double score;
}

// src/main/java/com/socialcommerce/feed/service/FeedService.java
@Service
@RequiredArgsConstructor
public class FeedService {
    private final MongoTemplate mongoTemplate;
    
    public List<FeedItem> getFeedForUser(String userId) {
        Query query = Query.query(Criteria.where("userId").is(userId))
            .with(Sort.by(Sort.Direction.DESC, "score"))
            .limit(20);
        return mongoTemplate.find(query, FeedItem.class);
    }
}

// src/main/java/com/socialcommerce/moderation/model/ModerationDecision.java
@Document(collection = "moderation_decisions")
@Data
public class ModerationDecision {
    @Id
    private String id;
    private String contentId;
    private ModerationStatus status;
    private String reason;
}

@Service
public class AIModerationService {
    public ModerationDecision moderateContent(String content) {
        // Implement your AI logic here
        return new ModerationDecision(content, 
            containsBadWords(content) ? REJECTED : APPROVED);
    }
}

// src/test/java/com/socialcommerce/chat/ChatServiceTest.java
@SpringBootTest
class ChatServiceTest {
    @Autowired
    private ChatRepository chatRepo;
    
    @Test
    void testSaveMessage() {
        ChatMessage msg = new ChatMessage("prod1", "user1", "Hello!");
        chatRepo.save(msg);
        assertNotNull(msg.getId());
    }
}

// src/test/java/com/socialcommerce/feed/FeedIT.java
@Testcontainers
@SpringBootTest
class FeedIT {
    @Container
    static MongoDBContainer mongo = new MongoDBContainer("mongo:6.0");
    
    @DynamicPropertySource
    static void setProperties(DynamicPropertyRegistry registry) {
        registry.add("spring.data.mongodb.uri", mongo::getReplicaSetUrl);
    }
    
    @Test
    void testFeedGeneration() {
        // Test with real MongoDB
    }
}