/*
 * Copyright 2012 Takao Nakaguchi
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.trie4j.patricia.multilayer.node;

import org.trie4j.NodeVisitor;
import org.trie4j.patricia.multilayer.Node;
import org.trie4j.patricia.multilayer.labeltrie.LabelNode;

public class SingleChildInternalCharsNode extends CharsNode {
	public SingleChildInternalCharsNode(char[] letters, Node child) {
		super(letters);
		this.child = child;
	}

	public Node[] getChildren() {
		return new Node[]{child};
	}

	public void setChildren(Node[] children) {
		throw new UnsupportedOperationException();
	}

	@Override
	public void setChild(int index, Node child) {
		if(index != 0) throw new IllegalStateException();
		this.child = child;
	}

	public Node getChild(char c){
		if(child.getFirstLetter() == c) return child;
		return null;
	}

	public Node addChild(int index, Node n){
		if(index == 0){
			return new InternalCharsNode(getLetters(), new Node[]{n, child});
		} else{
			return new InternalCharsNode(getLetters(), new Node[]{child, n});
		}
	}

	public void visit(NodeVisitor visitor, int nest){
		super.visit(visitor, nest);
		nest++;
		child.visit(visitor, nest);
	}

	protected Node cloneWithLetters(char[] letters){
		return new SingleChildInternalCharsNode(letters, child);
	}

	protected Node newLabelTrieNode(LabelNode ln, Node[] children){
		if(children != null){
			if(children.length != 1) throw new IllegalArgumentException();
			return new SingleChildInternalLabelTrieNode(ln, children[0]);
		} else{
			return new LabelTrieNode(ln);
		}
	}

	private Node child;
}