package nju.seec.helper.logic.service.impl;

import nju.seec.helper.data.dao.SlideDAO;
import nju.seec.helper.data.entity.Course;
import nju.seec.helper.data.entity.Slide;
import nju.seec.helper.logic.convert.DTOConvertFactory;
import nju.seec.helper.logic.convert.EntityConvertFactory;
import nju.seec.helper.logic.service.CourseService;
import nju.seec.helper.logic.service.SlideService;
import nju.seec.helper.logic.vo.SlideVO;
import nju.seec.helper.util.enums.SlideState;
import nju.seec.helper.util.exception.HelperException;
import nju.seec.helper.web.dto.SlideDTO;
import org.springframework.cache.annotation.CacheConfig;
import org.springframework.cache.annotation.CacheEvict;
import org.springframework.cache.annotation.CachePut;
import org.springframework.cache.annotation.Cacheable;
import org.springframework.data.domain.Page;
import org.springframework.data.domain.Pageable;
import org.springframework.stereotype.Service;

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

/**
 * @author cst
 */
@Service
@CacheConfig(cacheNames = "slide")
public class SlideServiceImpl implements SlideService {
    private final SlideDAO slideDAO;

    private final CourseService courseService;

    public SlideServiceImpl(SlideDAO slideDAO, CourseService courseService) {
        this.slideDAO = slideDAO;
        this.courseService = courseService;
    }

    @Override
    public List<SlideVO> getSlides(String courseId, String key, Pageable pageable) {
        Page<Slide> slidePage = slideDAO.findByCourseIdAndNameContains(courseId, key, pageable);

        return slidePage.getContent().stream()
                .map(slide -> EntityConvertFactory.convert(slide, SlideVO.class))
                .collect(Collectors.toList());
    }

    @Override
    public List<SlideVO> getSlides(String key, Pageable pageable) {
        Page<Slide> slidePage = slideDAO.findByNameContains(key, pageable);

        return slidePage.getContent().stream()
                .map(slide -> EntityConvertFactory.convert(slide, SlideVO.class))
                .collect(Collectors.toList());
    }

    @Cacheable(key = "#slideId")
    @Override
    public SlideVO getOneSlide(int slideId) {
        Slide slide = findSlideById(slideId);
        return EntityConvertFactory.convert(slide, SlideVO.class);
    }

    @Override
    public SlideVO create(SlideDTO slideDTO) {
        Slide slide = new Slide();
        Course course = courseService.findCourseById(slideDTO.getCourseId());
        slide.setCourseId(course.getId());
        slide.setCourseName(course.getName());
        slide.setName(slideDTO.getName());
        slide.setState(SlideState.DRAFT);
        slide = slideDAO.save(slide);
        return EntityConvertFactory.convert(slide, SlideVO.class);
    }

    @CachePut(key = "#slideDTO.id")
    @Override
    public SlideVO update(SlideDTO slideDTO) {
        Slide slide = DTOConvertFactory.convert(slideDTO);
        slideDAO.save(slide);
        return EntityConvertFactory.convert(findSlideById(slideDTO.getId()), SlideVO.class);
    }

    @CacheEvict(key = "#slideId")
    @Override
    public void delete(int slideId) {
        slideDAO.deleteById(slideId);
    }

    private Slide findSlideById(int slideId) {
        return slideDAO.findById(slideId).orElseThrow(() -> HelperException.of(
                HelperException.ExceptionType.NOT_FOUND, "找不到幻灯片")
        );
    }
}