package com.rongyichuang.carousel.service;

import com.rongyichuang.carousel.dto.request.CarouselInput;
import com.rongyichuang.carousel.dto.request.CarouselSortOrderInput;
import com.rongyichuang.carousel.dto.response.CarouselResponse;
import com.rongyichuang.carousel.entity.Carousel;
import com.rongyichuang.carousel.repository.CarouselRepository;
import org.springframework.data.domain.Sort;
import org.springframework.util.StringUtils;
import com.rongyichuang.common.dto.PageResponse;
import com.rongyichuang.common.entity.Media;
import com.rongyichuang.common.exception.BusinessException;
import com.rongyichuang.common.repository.MediaRepository;
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 java.util.List;
import java.util.Map;
import java.util.stream.Collectors;

/**
 * 轮播图业务服务
 */
@Service
public class CarouselService {

    @Autowired
    private CarouselRepository carouselRepository;
    
    @Autowired
    private MediaRepository mediaRepository;

    /**
     * 分页查询轮播图
     */
    public PageResponse<CarouselResponse> getCarousels(int page, int size, String title) {
        Pageable pageable = org.springframework.data.domain.PageRequest.of(page, size, Sort.by(Sort.Direction.ASC, "sortOrder"));
        
        Page<Carousel> carouselPage;
        if (StringUtils.hasText(title)) {
            carouselPage = carouselRepository.findByTitleContaining(title, pageable);
        } else {
            carouselPage = carouselRepository.findAll(pageable);
        }
        
        List<CarouselResponse> responses = carouselPage.getContent().stream()
                .map(this::convertToResponse)
                .collect(Collectors.toList());
        
        // 批量查询媒体数量
        if (!responses.isEmpty()) {
            List<Long> carouselIds = responses.stream()
                    .map(CarouselResponse::getId)
                    .collect(Collectors.toList());
            
            // 查询媒体数量（targetType=4表示轮播图）
            List<Object[]> mediaCountResults = mediaRepository.countByTargetTypeAndTargetIdInAndState(4, carouselIds, 1);
            Map<Long, Integer> mediaCountMap = mediaCountResults.stream()
                    .collect(Collectors.toMap(
                            result -> (Long) result[0],
                            result -> ((Long) result[1]).intValue()
                    ));
            
            // 设置媒体数量
            responses.forEach(response -> {
                Integer mediaCount = mediaCountMap.getOrDefault(response.getId(), 0);
                response.setMediaCount(mediaCount);
            });
        }
        
        return new PageResponse<>(responses, carouselPage.getTotalElements(), carouselPage.getNumber(), carouselPage.getSize());
    }

    /**
     * 根据ID查询轮播图
     */
    public CarouselResponse getCarousel(Long id) {
        Carousel carousel = carouselRepository.findById(id)
                .orElseThrow(() -> new BusinessException("轮播图不存在"));
        
        CarouselResponse response = convertToResponse(carousel);
        
        // 查询媒体数量
        List<Media> mediaList = mediaRepository.findByTargetTypeAndTargetIdAndState(4, id, 1);
        response.setMediaCount(mediaList.size());
        
        return response;
    }

    /**
     * 获取播放列表
     */
    public List<CarouselResponse> getPlayList() {
        List<Carousel> carousels = carouselRepository.findPlayList();
        return carousels.stream()
                .map(this::convertToResponse)
                .collect(Collectors.toList());
    }

    /**
     * 保存轮播图
     */
    @Transactional
    public CarouselResponse saveCarousel(CarouselInput input) {
        Carousel carousel;
        if (input.getId() != null) {
            // 修改
            carousel = carouselRepository.findById(input.getId())
                    .orElseThrow(() -> new BusinessException("轮播图不存在"));
        } else {
            // 新增
            carousel = new Carousel();
        }
        
        carousel.setTitle(input.getTitle());
        carousel.setContent(input.getContent());
        carousel.setSortOrder(input.getSortOrder());
        
        carousel = carouselRepository.save(carousel);
        
        return convertToResponse(carousel);
    }

    /**
     * 删除轮播图
     */
    @Transactional
    public boolean deleteCarousel(Long id) {
        Carousel carousel = carouselRepository.findById(id)
                .orElseThrow(() -> new BusinessException("轮播图不存在"));
        
        // 逻辑删除
        carousel.setState(0);
        carouselRepository.save(carousel);
        
        return true;
    }

    /**
     * 批量更新播放顺序
     */
    @Transactional
    public boolean updateSortOrders(List<CarouselSortOrderInput> sortOrders) {
        System.out.println("=== CarouselService.updateSortOrders 开始执行 ===");
        System.out.println("接收到的排序数据数量: " + sortOrders.size());
        
        for (CarouselSortOrderInput sortOrderInput : sortOrders) {
            System.out.println("处理轮播图ID: " + sortOrderInput.getId() + ", 新排序值: " + sortOrderInput.getSortOrder());
            
            Carousel carousel = carouselRepository.findById(sortOrderInput.getId())
                    .orElseThrow(() -> new BusinessException("轮播图不存在，ID：" + sortOrderInput.getId()));
            
            System.out.println("找到轮播图: " + carousel.getTitle() + ", 当前排序值: " + carousel.getSortOrder());
            
            carousel.setSortOrder(sortOrderInput.getSortOrder());
            carouselRepository.save(carousel);
            
            System.out.println("已更新轮播图排序值为: " + sortOrderInput.getSortOrder());
        }
        
        System.out.println("=== CarouselService.updateSortOrders 执行完成 ===");
        return true;
    }

    /**
     * 转换为响应DTO
     */
    private CarouselResponse convertToResponse(Carousel carousel) {
        CarouselResponse response = new CarouselResponse();
        response.setId(carousel.getId());
        response.setTitle(carousel.getTitle());
        response.setContent(carousel.getContent());
        response.setSortOrder(carousel.getSortOrder());
        response.setCreateTime(carousel.getCreateTime());
        response.setUpdateTime(carousel.getUpdateTime());
        return response;
    }
}