package com.rongyichuang.news.service;

import com.rongyichuang.news.dto.NewsInput;
import com.rongyichuang.news.dto.NewsResponse;
import com.rongyichuang.news.entity.News;
import com.rongyichuang.news.repository.NewsRepository;
import com.rongyichuang.common.dto.PageRequest;
import com.rongyichuang.common.dto.PageResponse;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.domain.Page;
import org.springframework.data.domain.Pageable;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;
import org.springframework.util.StringUtils;

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

@Service
@Transactional
public class NewsService {

    @Autowired
    private NewsRepository newsRepository;

    /**
     * 分页查询新闻列表
     */
    public PageResponse<NewsResponse> findNews(PageRequest pageRequest, String title, Integer state) {
        Pageable pageable = pageRequest.toPageable();
        Page<News> page;

        boolean hasTitle = StringUtils.hasText(title);
        if (state != null) {
            if (hasTitle) {
                page = newsRepository.findByStateAndTitleContainingOrderByCreateTimeDesc(state, title, pageable);
            } else {
                page = newsRepository.findByStateOrderByCreateTimeDesc(state, pageable);
            }
        } else if (hasTitle) {
            page = newsRepository.findByTitleContainingOrderByCreateTimeDesc(title, pageable);
        } else {
            page = newsRepository.findAll(pageable);
        }

        List<NewsResponse> content = page.getContent().stream()
                .map(NewsResponse::new)
                .collect(Collectors.toList());

        return new PageResponse<>(content, page.getTotalElements(), page.getNumber(), page.getSize());
    }

    /**
     * 获取新闻详情
     */
    public NewsResponse findById(Long id) {
        Optional<News> newsOpt = newsRepository.findById(id);
        return newsOpt.map(NewsResponse::new).orElse(null);
    }

    /**
     * 获取已发布的新闻详情（用于前端展示）
     */
    public NewsResponse findPublishedNewsById(Long id) {
        News news = newsRepository.findPublishedNewsById(id);
        return news != null ? new NewsResponse(news) : null;
    }

    /**
     * 保存新闻（新增或编辑）
     */
    public NewsResponse saveNews(NewsInput input) {
        News news;

        if (input.isNew()) {
            // 新增新闻
            news = new News();
        } else {
            // 编辑新闻
            Optional<News> existingOpt = newsRepository.findById(input.getId());
            if (!existingOpt.isPresent()) {
                throw new RuntimeException("新闻不存在");
            }
            news = existingOpt.get();
        }

        // 设置基本信息
        news.setTitle(input.getTitle());
        news.setContent(input.getContent());
        news.setSummary(input.getSummary());
        news.setCoverImage(input.getCoverImage());
        news.setAuthor(input.getAuthor());
        news.setState(input.getState());

        // 保存新闻
        news = newsRepository.save(news);

        return new NewsResponse(news);
    }

    /**
     * 删除新闻（软删除）
     */
    public boolean deleteNews(Long id) {
        Optional<News> newsOpt = newsRepository.findById(id);
        if (newsOpt.isPresent()) {
            News news = newsOpt.get();
            news.setState(2); // 设置为关闭状态
            newsRepository.save(news);
            return true;
        }
        return false;
    }

    /**
     * 更新新闻状态
     */
    public boolean updateNewsState(Long id, Integer state) {
        Optional<News> newsOpt = newsRepository.findById(id);
        if (newsOpt.isPresent()) {
            News news = newsOpt.get();
            news.setState(state);
            newsRepository.save(news);
            return true;
        }
        return false;
    }

    /**
     * 获取已发布的新闻列表（用于前端展示）
     */
    public List<NewsResponse> findPublishedNews() {
        List<News> newsList = newsRepository.findPublishedNews();
        return newsList.stream()
                .map(NewsResponse::new)
                .collect(Collectors.toList());
    }

    /**
     * 获取已发布的新闻列表（分页，用于前端展示）
     */
    public PageResponse<NewsResponse> findPublishedNews(PageRequest pageRequest) {
        Pageable pageable = pageRequest.toPageable();
        Page<News> page = newsRepository.findPublishedNews(pageable);

        List<NewsResponse> content = page.getContent().stream()
                .map(NewsResponse::new)
                .collect(Collectors.toList());

        return new PageResponse<>(content, page.getTotalElements(), page.getNumber(), page.getSize());
    }
}