/*
 * 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.tail.index;

import java.io.Externalizable;
import java.io.IOException;
import java.io.ObjectInput;
import java.io.ObjectOutput;

import org.trie4j.util.FastBitSet;

public class SBVTailIndexBuilder
implements Externalizable, TailIndexBuilder{
	public SBVTailIndexBuilder() {
		bs = new FastBitSet();
	}

	public SBVTailIndexBuilder(int initialCapacity) {
		bs = new FastBitSet(initialCapacity);
	}

	@Override
	public void add(int nodeId, int start, int end) {
		if(nodeId != current){
			throw new IllegalArgumentException("nodeId must be a strictly increasing.");
		}
		int index = bs.size();
		for(int i = start; i < end; i++){
			bs.set(index++);
		}
		bs.unsetIfLE(index);
		current++;
	}

	@Override
	public void addEmpty(int nodeId) {
		if(nodeId != current){
			throw new IllegalArgumentException("nodeId must be a strictly increasing.");
		}
		bs.unsetIfLE(bs.size());
		current++;
	}

	@Override
	public void trimToSize() {
		bs.trimToSize();
	}

	@Override
	public TailIndex build() {
		return new SBVTailIndex(bs.getBytes(), bs.size(), current);
	}

	@Override
	public void readExternal(ObjectInput in)
	throws ClassNotFoundException, IOException{
		bs = (FastBitSet)in.readObject();
	}

	@Override
	public void writeExternal(ObjectOutput out) throws IOException{
		out.writeObject(bs);
	}

	private int current;
	private FastBitSet bs;
	private static final long serialVersionUID = 8843853578097509573L;
}