package com.heketai.website.common.utils;

import com.heketai.website.entity.dto.TreeNode;
import lombok.experimental.UtilityClass;

import java.util.ArrayList;
import java.util.List;
import java.util.Objects;

/**
 * @author xjl
 */
@UtilityClass
@SuppressWarnings("all")
public class TreeUtil {

    /**
     * 使用递归方法建树
     *
     * @param treeNodes
     * @return
     */
    public <T extends TreeNode> List<T> buildByRecursive(List<T> treeNodes, Object root) {
        List<T> trees = new ArrayList<>();
        for (T treeNode : treeNodes) {
            if (Objects.equals(root, treeNode.getParentId())) {
                trees.add(findChildren(treeNode, treeNodes));
            }
        }
        return trees;
    }

    /**
     * 递归查找子节点
     *
     * @param treeNodes
     * @return
     */
    public <T extends TreeNode> T findChildren(T treeNode, List<T> treeNodes) {
        for (T it : treeNodes) {
            if (treeNode.getId() == it.getParentId()) {
                if (Objects.isNull(treeNode.getChildren())) {
                    treeNode.setChildren(new ArrayList<>());
                }
                treeNode.add(findChildren(it, treeNodes));
            }
        }
        return treeNode;
    }
}
