backend/src/main/java/nju/seec/helper/logic/convert/DTOConvertFactory.java

package nju.seec.helper.logic.convert;

import com.google.common.collect.ImmutableMap;
import lombok.experimental.UtilityClass;
import nju.seec.helper.data.entity.Item;
import nju.seec.helper.data.entity.Slide;
import nju.seec.helper.web.dto.SlideDTO;
import org.springframework.beans.BeanUtils;

import java.util.Map;
import java.util.stream.Collectors;

/**
 * @author cst
 */
@UtilityClass
public class DTOConvertFactory {
    @SuppressWarnings("rawtypes")
    private static final Map<Class, DTOConverter> MAP = new ImmutableMap.Builder<Class, DTOConverter>()
            .put(SlideDTO.class, (DTOConverter<SlideDTO, Slide>) slideDTO -> {
                Slide slide = new Slide();
                BeanUtils.copyProperties(slideDTO, slide, "items");
                slide.setItems(slideDTO.getItems().stream()
                        .map(itemDTO -> {
                            Item item = new Item();
                            BeanUtils.copyProperties(itemDTO, item);
                            return item;
                        }).collect(Collectors.toList()));
                return slide;
            })
            .build();

    @SuppressWarnings("unchecked")
    public <DTO, Entity> Entity convert(DTO dto) {
        return (Entity) MAP.get(dto.getClass())
                .convert(dto);
    }
}