/*
 * Copyright 2014 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.util;

import java.io.Serializable;
import java.util.Arrays;
import java.util.NoSuchElementException;

import org.trie4j.bv.BytesRank0OnlySuccinctBitVector;

public class SBVIntMap<T> implements Serializable{
	public SBVIntMap() {
		values = new Object[]{};
		valueIndices = new BytesRank0OnlySuccinctBitVector();
	}

	public SBVIntMap(int initialCapacity){
		values = new Object[]{};
		valueIndices = new BytesRank0OnlySuccinctBitVector(initialCapacity);
	}

	public int size(){
		return valueIndices.size();
	}

	public int valuesSize(){
		return current;
	}

	public int addValue(T value){
		valueIndices.append0();
		if(current >= values.length){
			values = Arrays.copyOf(values, (int)(values.length * 1.2 + 1));
		}
		values[current] = value;
		current++;
		return valueIndices.size();
	}

	public int addNone(){
		valueIndices.append1();
		return valueIndices.size();
	}

	@SuppressWarnings("unchecked")
	public T get(int id){
		if(!valueIndices.isZero(id)){
			throw new NoSuchElementException("No element exists at " + id);
		}
		return (T)values[valueIndices.rank0(id) - 1];
	}

	@SuppressWarnings("unchecked")
	public T getUnsafe(int id){
		return (T)values[valueIndices.rank0(id) - 1];
	}

	public void set(int id, T value){
		if(!valueIndices.isZero(id)) throw new IllegalStateException(
				"try to set value for invalid id.");
		values[valueIndices.rank0(id) - 1] = value;
	}

	private int current;
	private Object[] values;
	private BytesRank0OnlySuccinctBitVector valueIndices = new BytesRank0OnlySuccinctBitVector();
	private static final long serialVersionUID = -4753279563025571408L;
}