/**
 * BladeX Commercial License Agreement
 * Copyright (c) 2018-2099, https://bladex.cn. All rights reserved.
 * <p>
 * Use of this software is governed by the Commercial License Agreement
 * obtained after purchasing a license from BladeX.
 * <p>
 * 1. This software is for development use only under a valid license
 * from BladeX.
 * <p>
 * 2. Redistribution of this software's source code to any third party
 * without a commercial license is strictly prohibited.
 * <p>
 * 3. Licensees may copyright their own code but cannot use segments
 * from this software for such purposes. Copyright of this software
 * remains with BladeX.
 * <p>
 * Using this software signifies agreement to this License, and the software
 * must not be used for illegal purposes.
 * <p>
 * THIS SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY. The author is
 * not liable for any claims arising from secondary or illegal development.
 * <p>
 * Author: Chill Zhuang (bladejava@qq.com)
 */
package org.springblade.core.tool.node;

import java.util.List;

/**
 * 森林节点归并类
 *
 * @author smallchill
 */
public class ForestNodeMerger {

	/**
	 * 将节点数组归并为一个森林（多棵树）（填充节点的children域）
	 * 时间复杂度为O(n^2)
	 *
	 * @param items 节点域
	 * @return 多棵树的根节点集合
	 */
	public static <T extends INode<T>> List<T> merge(List<T> items) {
		ForestNodeManager<T> forestNodeManager = new ForestNodeManager<>(items);
		items.forEach(forestNode -> {
			if (forestNode.getParentId() != 0) {
				INode<T> node = forestNodeManager.getTreeNodeAt(forestNode.getParentId());
				if (node != null) {
					node.getChildren().add(forestNode);
				} else {
					forestNodeManager.addParentId(forestNode.getId());
				}
			}
		});
		return forestNodeManager.getRoot();
	}

}
