package com.ruoyi.measuringinstrumentledger.service.impl;


import com.baomidou.mybatisplus.core.metadata.IPage;
import com.baomidou.mybatisplus.extension.plugins.pagination.Page;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.ruoyi.measuringinstrumentledger.dto.SparePartsDto;
import com.ruoyi.measuringinstrumentledger.mapper.SparePartsMapper;
import com.ruoyi.measuringinstrumentledger.pojo.SpareParts;
import com.ruoyi.measuringinstrumentledger.service.SparePartsService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

@Service
public class SparePartsServiceImpl extends ServiceImpl<SparePartsMapper, SpareParts> implements SparePartsService {
    @Autowired
    private SparePartsMapper sparePartsMapper;
    @Override
    public IPage<SparePartsDto> listPage(Page page, SpareParts spareParts) {
        return sparePartsMapper.listPage(page,spareParts);
    }

    @Override
    public List<SparePartsDto> getTree() {
        SpareParts spareParts = new SpareParts();
        IPage<SparePartsDto> sparePartsDtoIPage = sparePartsMapper.listPage(new Page<>(1, -1), spareParts);
        List<SparePartsDto> records = sparePartsDtoIPage.getRecords();
        return buildTree(records);
    }


    /**
     * 将扁平结构数据转换为树形结构
     * @param flatData 扁平节点列表
     * @return 树形结构根节点列表
     */
    public static List<SparePartsDto> buildTree(List<SparePartsDto> flatData) {
        List<SparePartsDto> result = new ArrayList<>();
        if (flatData == null || flatData.isEmpty()) {
            return result;  // 空输入直接返回空列表
        }

        // 1. 创建节点映射表，存储所有节点并初始化子节点列表
        Map<Long, SparePartsDto> nodeMap = new HashMap<>();
        for (SparePartsDto node : flatData) {
            // 确保子节点列表初始化(避免空指针异常)
            if (node.getChildren() == null) {
                node.setChildren(new ArrayList<>());
            }
            nodeMap.put(node.getId(), node);
        }

        // 2. 构建树形结构
        for (SparePartsDto node : flatData) {
            Long parentId = node.getParentId();
            if (parentId == null || !nodeMap.containsKey(parentId)) {
                // 无父节点或父节点不存在，作为根节点
                result.add(node);
            } else {
                // 有父节点，添加到父节点的子节点列表
                SparePartsDto parentNode = nodeMap.get(parentId);
                parentNode.getChildren().add(node);
            }
        }

        return result;
    }
}