/*
    * Copyright 2010 Daniel Kurka
    * 
    * 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 com.googlecode.mgwt.collection.shared.java;
  
  import java.util.ArrayList;
  import java.util.Set;
  
  import com.googlecode.mgwt.collection.shared.LightArray;
  
  /**
   * An implementation of {@link LightArray} used on the jvm
   * 
   * @author Daniel Kurka
   * 
   * @param <T>
   */
  public class JavaLightArray<T> implements LightArray<T> {
  
  	private ArrayList<T> list;
  
    /**
     * Construct a {@link JavaLightArray}
     */
  	public JavaLightArray() {
  		list = new ArrayList<T>();
  	}
  
  	@Override
  	public T shift() {
  		return list.remove(0);
  	}
  
  	@Override
  	public T get(int index) {
  		// behave like js!
  		if (index < 0 || index >= list.size())
  			return null;
  		return list.get(index);
  	}
  
  	@Override
  	public void set(int index, T value) {
  		// behave like js!
  		if (index < 0)
  			return;
  		if (index >= list.size()) {
  			for (int i = list.size(); i < index; i++) {
  				list.add(null);
  			}
  			list.add(value);
  		} else {
  			list.set(index, value);
  		}
  
  	}
  
  	@Override
  	public int length() {
  		return list.size();
  	}
  
  	@Override
  	public void unshift(T value) {
  		list.add(0, value);
  
  	}
  
  	@Override
  	public void push(T value) {
  		list.add(value);
  
  	}
  
    /**
     * Construct a {@link JavaLightArray} from a set
     * 
     * @param <T> the types to store in the array
     * @param set the set with the initial values
     * @return the new array
     */
  	public static <T> JavaLightArray<T> fromSet(Set<T> set) {
  		JavaLightArray<T> array = new JavaLightArray<T>();
  		for (T t : set) {
  			array.push(t);
  		}
  		return array;
 	}
 
 }