/*
 * Copyright (C) 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;

import java.io.Serializable;

import org.trie4j.NodeVisitor;

public class PatriciaTrieNode
implements Serializable, org.trie4j.Node{
	public PatriciaTrieNode() {
		this(new char[]{}, false);
	}

	public PatriciaTrieNode(char[] letters, boolean terminated) {
		this(letters, terminated, emptyChildren);
	}

	public PatriciaTrieNode(char[] letters, boolean terminated, PatriciaTrieNode[] children) {
		this.letters = letters;
		this.terminate = terminated;
		this.children = children;
	}

	public PatriciaTrieNode[] getChildren() {
		return children;
	}
	
	public void setChildren(PatriciaTrieNode[] children){
		this.children = children;
	}

	public char[] getLetters() {
		return letters;
	}
	
	public void setLetters(char[] letters){
		this.letters = letters;
	}

	public boolean isTerminate() {
		return terminate;
	}
	
	public void setTerminate(boolean terminate){
		this.terminate = terminate;
	}

	public PatriciaTrieNode getChild(char c){
		int end = children.length;
		if(end > 16){
			int start = 0;
			while(start < end){
				int i = (start + end) / 2;
				PatriciaTrieNode n = children[i];
				int d = c - n.letters[0];
				if(d == 0) return n;
				if(d < 0){
					end = i;
				} else if(start == i){
					break;
				} else{
					start = i;
				}
			}
		} else{
			for(int i = 0; i < end; i++){
				PatriciaTrieNode n = children[i];
				if(n.letters[0] == c) return n;
			}
		}
		return null;
	}

	public void visit(NodeVisitor visitor, int nest){
		if(!visitor.visit(this, nest)) return;
		nest++;
		for(PatriciaTrieNode n : children){
			n.visit(visitor, nest);
		}
	}

	public PatriciaTrieNode addChild(int index, PatriciaTrieNode n){
		PatriciaTrieNode[] newc = new PatriciaTrieNode[children.length + 1];
		System.arraycopy(children,  0, newc, 0, index);
		newc[index] = n;
		System.arraycopy(children,  index, newc, index + 1, children.length - index);
		this.children = newc;
		return this;
	}

	private char[] letters;
	private boolean terminate;
	private PatriciaTrieNode[] children;
	private static PatriciaTrieNode[] emptyChildren = {};
	private static final long serialVersionUID = -1625115329685564809L;
}