package frame.object.data;

import chat.server.call.IJSONWriter;
import frame.object.meta.EntityMeta;


public class EntityTree extends EntitySet {

	private EntitySet rootSet;
	
	public EntityTree(EntityMeta tableMeta) {
		super(tableMeta);
		rootSet = new EntitySet(tableMeta);
	}

	public EntitySet getChildren(ID parentId) throws DataException {
		Node parent = getNode(parentId);
		
		if (parent == null) {
			return null;
		}
		
		return parent.children;
	}

	public Node getNode(ID id) throws DataException {
		Entity result = getEntity(id);
		return (Node) result;
	}

	public EntitySet getRootSet() {
		return rootSet;
	}
	
	public void initRelation() throws DataException {
		initFamilyRelation();
		initLevelRelation();
	}
	
	public void initFamilyRelation() throws DataException {
		for (Entity entity: this) {
			Node node = (Node) entity;
			ID parentId = node.getParentId();
			
			if (parentId.isEmpty()) {
				node.level = 0;
				rootSet.append(node);
				continue;
			}
			
			Node parent = getNode(parentId);
			
			if (parent == null) {
				continue;
			}
			
			parent.addChild(node);
		}
	}
	
	public void initLevelRelation() throws DataException {
		for (Entity entity: rootSet) {
			Node node = (Node) entity;
			doInitLevelRelation(node);
		}
	}

	private void doInitLevelRelation(Node parent) {
		EntitySet children = parent.getChildren();
		
		for (Entity entity: children) {
			Node child = (Node) entity;
			child.level = parent.level + 1;
			
			EntitySet offsprings = child.getChildren();
			
			for (Entity offspring: offsprings) {
				doInitLevelRelation((Node)offspring);
			}
		}
	}
	
	@Override
	public void writeJSONObject(IJSONWriter writer) {
		writer.beginArray();
		
		for (Entity entity: rootSet) {
			Node node = (Node)entity;
			node.writeJSONObject(writer);
		}
		
		writer.endArray();	
	}

}