smile-picture-backend/src/main/java/edu/whut/smilepicturebackend/service/impl/PictureServiceImpl.java

package edu.whut.smilepicturebackend.service.impl;

import cn.hutool.core.collection.CollUtil;
import cn.hutool.core.util.ObjUtil;
import cn.hutool.core.util.StrUtil;
import com.baomidou.mybatisplus.core.conditions.query.LambdaQueryWrapper;
import com.baomidou.mybatisplus.core.toolkit.Wrappers;
import com.baomidou.mybatisplus.extension.plugins.pagination.Page;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import edu.whut.smilepicturebackend.exception.ErrorCode;
import edu.whut.smilepicturebackend.exception.ThrowUtils;
import edu.whut.smilepicturebackend.manager.FileManager;
import edu.whut.smilepicturebackend.mapper.PictureMapper;
import edu.whut.smilepicturebackend.model.dto.picture.PictureQueryRequest;
import edu.whut.smilepicturebackend.model.dto.picture.PictureUploadRequest;
import edu.whut.smilepicturebackend.model.entity.Picture;
import edu.whut.smilepicturebackend.model.entity.User;
import edu.whut.smilepicturebackend.model.file.UploadPictureResult;
import edu.whut.smilepicturebackend.model.vo.PictureVO;
import edu.whut.smilepicturebackend.model.vo.UserVO;
import edu.whut.smilepicturebackend.service.PictureService;
import edu.whut.smilepicturebackend.service.UserService;
import lombok.RequiredArgsConstructor;
import org.springframework.beans.BeanUtils;
import org.springframework.stereotype.Service;
import org.springframework.web.multipart.MultipartFile;

import javax.servlet.http.HttpServletRequest;
import java.util.Date;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.stream.Collectors;

/**
* @author 张三
* @description 针对表【picture(图片)】的数据库操作Service实现
* @createDate 2025-06-11 11:23:11
*/
@Service
@RequiredArgsConstructor
public class PictureServiceImpl extends ServiceImpl<PictureMapper, Picture>
    implements PictureService {
    private final FileManager fileManager;
    private final UserService userService;

    @Override
    public void validPicture(Picture picture) {
        ThrowUtils.throwIf(picture == null, ErrorCode.PARAMS_ERROR);
        // 从对象中取值
        Long id = picture.getId();
        String url = picture.getUrl();
        String introduction = picture.getIntroduction();
        // 修改数据时，id 不能为空，有参数则校验
        ThrowUtils.throwIf(ObjUtil.isNull(id), ErrorCode.PARAMS_ERROR, "id 不能为空");
        // 如果传递了 url，才校验
        if (StrUtil.isNotBlank(url)) {
            ThrowUtils.throwIf(url.length() > 1024, ErrorCode.PARAMS_ERROR, "url 过长");
        }
        if (StrUtil.isNotBlank(introduction)) {
            ThrowUtils.throwIf(introduction.length() > 800, ErrorCode.PARAMS_ERROR, "简介过长");
        }
    }
    @Override
    public PictureVO uploadPicture(MultipartFile multipartFile, PictureUploadRequest pictureUploadRequest, User loginUser) {
        // 校验参数
        ThrowUtils.throwIf(loginUser == null, ErrorCode.NO_AUTH_ERROR);

        // 判断是新增还是删除
        Long pictureId = null;
        if (pictureUploadRequest != null) {
            pictureId = pictureUploadRequest.getId();
        }
        // 如果是更新，判断图片是否存在
        if (pictureId != null) {
            boolean exists=this.lambdaQuery()
                            .eq(Picture::getId,pictureId)
                                    .exists();
            ThrowUtils.throwIf(!exists, ErrorCode.NOT_FOUND_ERROR, "图片不存在");
        }
        // 上传图片，得到图片信息
        String uploadPathPrefix;
        //公共图库下，每个用户有自己的userid管理的文件夹。
        uploadPathPrefix = String.format("public/%s", loginUser.getId());
        UploadPictureResult uploadPictureResult = fileManager.uploadPicture(multipartFile, uploadPathPrefix);
        // 构造要入库的图片信息
        Picture picture = new Picture();
        // 复制同名属性（url、name、picSize、picWidth、picHeight、picScale、picFormat）
        BeanUtils.copyProperties(uploadPictureResult, picture);
        picture.setUserId(loginUser.getId());

        // 操作数据库
        // 如果 pictureId 不为空，表示更新，否则是新增
        if (pictureId != null) {
            // 如果是更新，需要补充 id 和编辑时间
            picture.setId(pictureId);
            picture.setEditTime(new Date());
        }
        boolean result = this.saveOrUpdate(picture);
        ThrowUtils.throwIf(!result, ErrorCode.OPERATION_ERROR, "图片上传失败，数据库操作失败");
        return PictureVO.objToVo(picture);
    }

    @Override
    public LambdaQueryWrapper<Picture> getQueryWrapper(PictureQueryRequest req) {
        LambdaQueryWrapper<Picture> qw = Wrappers.lambdaQuery(Picture.class);
        if (req == null) {
            return qw;
        }

        // 精简版条件构造
        qw.eq(ObjUtil.isNotEmpty(req.getId()), Picture::getId, req.getId())
                .eq(ObjUtil.isNotEmpty(req.getUserId()), Picture::getUserId, req.getUserId())
                .like(StrUtil.isNotBlank(req.getName()), Picture::getName, req.getName())
                .like(StrUtil.isNotBlank(req.getIntroduction()), Picture::getIntroduction, req.getIntroduction())
                .like(StrUtil.isNotBlank(req.getPicFormat()), Picture::getPicFormat, req.getPicFormat())
                .eq(StrUtil.isNotBlank(req.getCategory()), Picture::getCategory, req.getCategory())
                .eq(ObjUtil.isNotEmpty(req.getPicWidth()), Picture::getPicWidth, req.getPicWidth())
                .eq(ObjUtil.isNotEmpty(req.getPicHeight()), Picture::getPicHeight, req.getPicHeight())
                .eq(ObjUtil.isNotEmpty(req.getPicSize()), Picture::getPicSize, req.getPicSize())
                .eq(ObjUtil.isNotEmpty(req.getPicScale()), Picture::getPicScale, req.getPicScale())
                .ge(ObjUtil.isNotEmpty(req.getStartEditTime()), Picture::getEditTime, req.getStartEditTime())
                .lt(ObjUtil.isNotEmpty(req.getEndEditTime()), Picture::getEditTime, req.getEndEditTime());

        // 全字段模糊搜索
        if (StrUtil.isNotBlank(req.getSearchText())) {
            qw.and(w -> w
                    .like(Picture::getName, req.getSearchText())
                    .or()
                    .like(Picture::getIntroduction, req.getSearchText())
            );
        }

        // JSON 数组 tags 查询
        if (CollUtil.isNotEmpty(req.getTags())) {
            req.getTags().forEach(tag ->
                    qw.like(Picture::getTags, "\"" + tag + "\"")
            );
        }

        // 动态排序：转下划线字段名并手工拼接
        if (StrUtil.isNotBlank(req.getSortField())) {
            String column = StrUtil.toUnderlineCase(req.getSortField());
            String direction = "ascend".equalsIgnoreCase(req.getSortOrder()) ? "ASC" : "DESC";
            qw.last("ORDER BY " + column + " " + direction);
        }

        return qw;
    }

    @Override
    public PictureVO getPictureVO(Picture picture, HttpServletRequest request) {
        // 对象转封装类
        PictureVO pictureVO = PictureVO.objToVo(picture);
        // 关联查询用户信息
        Long userId = picture.getUserId();
        if (userId != null && userId > 0) {
            User user = userService.getById(userId);
            UserVO userVO = userService.getUserVO(user);
            pictureVO.setUser(userVO);
        }
        return pictureVO;
    }

    @Override
    public Page<PictureVO> getPictureVOPage(Page<Picture> picturePage, HttpServletRequest request) {
        List<Picture> pictureList = picturePage.getRecords();
        Page<PictureVO> pictureVOPage = new Page<>(picturePage.getCurrent(), picturePage.getSize(), picturePage.getTotal());
        if (CollUtil.isEmpty(pictureList)) {
            return pictureVOPage;
        }
        // 对象列表 => 封装对象列表
        List<PictureVO> pictureVOList = pictureList.stream()
                .map(PictureVO::objToVo)
                .collect(Collectors.toList());
        // 1. 关联查询用户信息
        // 1,2,3,4
        Set<Long> userIdSet = pictureList.stream().map(Picture::getUserId).collect(Collectors.toSet());
        // 1 => user1, 2 => user2
        Map<Long, List<User>> userIdUserListMap = userService.listByIds(userIdSet).stream()
                .collect(Collectors.groupingBy(User::getId));
        // 2. 填充信息
        pictureVOList.forEach(pictureVO -> {
            Long userId = pictureVO.getUserId();
            User user = null;
            if (userIdUserListMap.containsKey(userId)) {
                user = userIdUserListMap.get(userId).get(0);
            }
            pictureVO.setUser(userService.getUserVO(user));
        });
        pictureVOPage.setRecords(pictureVOList);
        return pictureVOPage;
    }
}