package foundation.dao.preload;

import java.util.Comparator;

import foundation.json.IJSONProvider;
import foundation.json.IJSONWriter;
import foundation.util.MapList;

public class Tree<T extends Node> extends Bucket<T> implements IJSONProvider {

	private MapList<String, T> roots;
	
	public Tree() {
		roots = new MapList<String, T>();
	}
	
	@SuppressWarnings("unchecked")
	public void onAfterLoad(boolean sort) {
		//1. 初始化父子关系
		initRelation();
		
		//2. 排序
		if (!sort || roots.isEmpty()) {
			return;
		}
		
		for (T node: roots) {
			if (node.containsChildren()) {
				node.sort(null);
			}
		}
		
		T node = roots.get(0);
		Comparator<T> comparator = (Comparator<T>)node.createComparator();
		roots.sortList(comparator);
	}	

	public void onAfterLoad() {
		initRelation();
	}
	
	public void initRelation() {
		for (T item: items) {
			String id = item.getId();
			String parentId = item.getParentId();
			
			if (parentId == null) {
				roots.add(id, item);
				continue;
			}
			
			T parent = items.get(parentId);
			
			if (parent == null) {
				continue;
			}
			
			item.parent = parent;
			parent.addOneChild(item);
		}
	}
	
	@Override
	public void writeJSON(IJSONWriter writer) {
		writer.beginArray();
		
		for (Node item: roots) {
			writer.beginObject();
			item.writeJSONBody(writer);
			writer.endObject();
		}
		
		writer.endArray(); 
	}

	public MapList<String, T> getRoots() {
		return roots;
	}

	public void setRoots(MapList<String, T> roots) {
		this.roots = roots;
	}
	
}