OpenIsle/backend/src/main/java/com/openisle/service/PostReadService.java

package com.openisle.service;

import com.openisle.model.Post;
import com.openisle.model.PostRead;
import com.openisle.model.User;
import com.openisle.repository.PostReadRepository;
import com.openisle.repository.PostRepository;
import com.openisle.repository.UserRepository;
import lombok.RequiredArgsConstructor;
import org.springframework.stereotype.Service;

import java.time.LocalDateTime;

@Service
@RequiredArgsConstructor
public class PostReadService {
    private final PostReadRepository postReadRepository;
    private final UserRepository userRepository;
    private final PostRepository postRepository;

    public void recordRead(String username, Long postId) {
        if (username == null) return;
        User user = userRepository.findByUsername(username)
                .orElseThrow(() -> new com.openisle.exception.NotFoundException("User not found"));
        Post post = postRepository.findById(postId)
                .orElseThrow(() -> new com.openisle.exception.NotFoundException("Post not found"));
        postReadRepository.findByUserAndPost(user, post).ifPresentOrElse(pr -> {
            pr.setLastReadAt(LocalDateTime.now());
            postReadRepository.save(pr);
        }, () -> {
            PostRead pr = new PostRead();
            pr.setUser(user);
            pr.setPost(post);
            pr.setLastReadAt(LocalDateTime.now());
            postReadRepository.save(pr);
        });
    }

    public long countReads(String username) {
        User user = userRepository.findByUsername(username)
                .orElseThrow(() -> new com.openisle.exception.NotFoundException("User not found"));
        return postReadRepository.countByUser(user);
    }

    @org.springframework.transaction.annotation.Transactional
    public void deleteByPost(Post post) {
        postReadRepository.deleteByPost(post);
    }
}