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

package com.openisle.service;

import com.openisle.model.*;
import com.openisle.repository.PostChangeLogRepository;
import com.openisle.repository.PostRepository;
import com.openisle.repository.UserRepository;
import lombok.RequiredArgsConstructor;
import org.springframework.stereotype.Service;

import java.util.List;
import java.util.Set;
import java.util.stream.Collectors;

@Service
@RequiredArgsConstructor
public class PostChangeLogService {
    private final PostChangeLogRepository logRepository;
    private final PostRepository  postRepository;
    private final UserRepository userRepository;

    private User getSystemUser() {
        return userRepository.findByUsername("system")
                .orElseThrow(() -> new IllegalStateException("System user not found"));
    }

    public void recordContentChange(Post post, User user, String oldContent, String newContent) {
        PostContentChangeLog log = new PostContentChangeLog();
        log.setPost(post);
        log.setUser(user);
        log.setType(PostChangeType.CONTENT);
        log.setOldContent(oldContent);
        log.setNewContent(newContent);
        logRepository.save(log);
    }

    public void recordTitleChange(Post post, User user, String oldTitle, String newTitle) {
        PostTitleChangeLog log = new PostTitleChangeLog();
        log.setPost(post);
        log.setUser(user);
        log.setType(PostChangeType.TITLE);
        log.setOldTitle(oldTitle);
        log.setNewTitle(newTitle);
        logRepository.save(log);
    }

    public void recordCategoryChange(Post post, User user, String oldCategory, String newCategory) {
        PostCategoryChangeLog log = new PostCategoryChangeLog();
        log.setPost(post);
        log.setUser(user);
        log.setType(PostChangeType.CATEGORY);
        log.setOldCategory(oldCategory);
        log.setNewCategory(newCategory);
        logRepository.save(log);
    }

    public void recordTagChange(Post post, User user, Set<Tag> oldTags, Set<Tag> newTags) {
        PostTagChangeLog log = new PostTagChangeLog();
        log.setPost(post);
        log.setUser(user);
        log.setType(PostChangeType.TAG);
        log.setOldTags(oldTags.stream().map(Tag::getName).collect(Collectors.joining(",")));
        log.setNewTags(newTags.stream().map(Tag::getName).collect(Collectors.joining(",")));
        logRepository.save(log);
    }

    public void recordClosedChange(Post post, User user, boolean oldClosed, boolean newClosed) {
        PostClosedChangeLog log = new PostClosedChangeLog();
        log.setPost(post);
        log.setUser(user);
        log.setType(PostChangeType.CLOSED);
        log.setOldClosed(oldClosed);
        log.setNewClosed(newClosed);
        logRepository.save(log);
    }

    public void recordPinnedChange(Post post, User user, java.time.LocalDateTime oldPinnedAt, java.time.LocalDateTime newPinnedAt) {
        PostPinnedChangeLog log = new PostPinnedChangeLog();
        log.setPost(post);
        log.setUser(user);
        log.setType(PostChangeType.PINNED);
        log.setOldPinnedAt(oldPinnedAt);
        log.setNewPinnedAt(newPinnedAt);
        logRepository.save(log);
    }

    public void recordFeaturedChange(Post post, User user, boolean oldFeatured, boolean newFeatured) {
        PostFeaturedChangeLog log = new PostFeaturedChangeLog();
        log.setPost(post);
        log.setUser(user);
        log.setType(PostChangeType.FEATURED);
        log.setOldFeatured(oldFeatured);
        log.setNewFeatured(newFeatured);
        logRepository.save(log);
    }

    public void recordVoteResult(Post post) {
        PostVoteResultChangeLog log = new PostVoteResultChangeLog();
        log.setPost(post);
        log.setUser(getSystemUser());
        log.setType(PostChangeType.VOTE_RESULT);
        logRepository.save(log);
    }

    public void recordLotteryResult(Post post) {
        PostLotteryResultChangeLog log = new PostLotteryResultChangeLog();
        log.setPost(post);
        log.setUser(getSystemUser());
        log.setType(PostChangeType.LOTTERY_RESULT);
        logRepository.save(log);
    }

    public List<PostChangeLog> listLogs(Long postId) {
        Post post = postRepository.findById(postId)
                .orElseThrow(() -> new com.openisle.exception.NotFoundException("Post not found"));
        return logRepository.findByPostOrderByCreatedAtAsc(post);
    }
}