package com.ruoyi.technology.service.impl;

import com.baomidou.mybatisplus.core.conditions.query.LambdaQueryWrapper;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.ruoyi.technology.bean.dto.TechnologyBomStructureDto;
import com.ruoyi.technology.bean.vo.TechnologyBomStructureVo;
import com.ruoyi.technology.mapper.TechnologyBomStructureMapper;
import com.ruoyi.technology.pojo.TechnologyBomStructure;
import com.ruoyi.technology.service.TechnologyBomStructureService;
import lombok.RequiredArgsConstructor;
import org.springframework.beans.BeanUtils;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import java.util.*;

@Service
@RequiredArgsConstructor
public class TechnologyBomStructureServiceImpl extends ServiceImpl<TechnologyBomStructureMapper, TechnologyBomStructure> implements TechnologyBomStructureService {

    private final TechnologyBomStructureMapper technologyBomStructureMapper;

    /**
     * 保存BOM结构树，处理新增、更新和删除节点。
     */
    @Override
    @Transactional(rollbackFor = Exception.class)
    public Boolean addTechnologyBomStructure(TechnologyBomStructureDto dto) {
        Long bomId = dto.getBomId();
        List<TechnologyBomStructureDto> flatDtoList = new ArrayList<>();
        flattenTree(dto.getChildren(), flatDtoList);

        List<TechnologyBomStructure> dbList = this.list(new LambdaQueryWrapper<TechnologyBomStructure>()
                .eq(TechnologyBomStructure::getBomId, bomId));

        Set<Long> frontendIds = new HashSet<>();
        for (TechnologyBomStructureDto item : flatDtoList) {
            if (item.getId() != null) {
                frontendIds.add(item.getId());
            }
        }

        Set<Long> deleteIds = new HashSet<>();
        for (TechnologyBomStructure dbItem : dbList) {
            if (!frontendIds.contains(dbItem.getId())) {
                deleteIds.add(dbItem.getId());
            }
        }
        if (!deleteIds.isEmpty()) {
            this.removeByIds(deleteIds);
        }

        List<TechnologyBomStructure> insertList = new ArrayList<>();
        List<TechnologyBomStructure> updateList = new ArrayList<>();
        Map<String, TechnologyBomStructure> tempEntityMap = new HashMap<>();

        for (TechnologyBomStructureDto item : flatDtoList) {
            TechnologyBomStructure entity = new TechnologyBomStructure();
            BeanUtils.copyProperties(item, entity);
            entity.setBomId(bomId);
            if (item.getId() == null) {
                entity.setParentId(null);
                insertList.add(entity);
                tempEntityMap.put(item.getTempId(), entity);
            } else {
                updateList.add(entity);
            }
        }

        if (!insertList.isEmpty()) {
            this.saveBatch(insertList);
        }

        List<TechnologyBomStructure> parentFixList = new ArrayList<>();
        for (TechnologyBomStructureDto item : flatDtoList) {
            if (item.getId() == null && item.getParentTempId() != null) {
                TechnologyBomStructure child = tempEntityMap.get(item.getTempId());
                if (child == null) {
                    continue;
                }
                TechnologyBomStructure parent = tempEntityMap.get(item.getParentTempId());
                Long realParentId = parent != null ? parent.getId() : Long.valueOf(item.getParentTempId());
                child.setParentId(realParentId);
                parentFixList.add(child);
            }
        }

        if (!parentFixList.isEmpty()) {
            this.updateBatchById(parentFixList);
        }
        if (!updateList.isEmpty()) {
            this.updateBatchById(updateList);
        }
        return true;
    }

    /**
     * 根据BOM查询并组装结构树。
     */
    @Override
    public List<TechnologyBomStructureVo> listByBomId(Long bomId) {
        List<TechnologyBomStructureVo> list = technologyBomStructureMapper.listByBomId(bomId);
        Map<Long, TechnologyBomStructureVo> map = new HashMap<>();
        for (TechnologyBomStructureVo node : list) {
            node.setChildren(new ArrayList<>());
            map.put(node.getId(), node);
        }

        List<TechnologyBomStructureVo> tree = new ArrayList<>();
        for (TechnologyBomStructureVo node : list) {
            Long parentId = node.getParentId();
            if (parentId == null || parentId == 0L) {
                tree.add(node);
                continue;
            }
            TechnologyBomStructureVo parent = map.get(parentId);
            if (parent != null) {
                parent.getChildren().add(node);
            }
        }
        return tree;
    }

    /**
     * 将树形结构拍平成列表，便于统一保存。
     */
    private void flattenTree(List<TechnologyBomStructureDto> source, List<TechnologyBomStructureDto> result) {
        if (source == null) {
            return;
        }
        for (TechnologyBomStructureDto node : source) {
            result.add(node);
            flattenTree(node.getChildren(), result);
        }
    }
}