package org.apache.lucene.search.highlight;

/**
 * Copyright 2002-2004 The Apache Software Foundation
 *
 * 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.
 */

/**
 * Low-level class used to record information about a section of a document with
 * a score.
 * 
 * @author MAHarwood
 */
public class TextFragment
{
	StringBuffer markedUpText;

	int fragNum;

	int textStartPos;

	int textEndPos;

	float score;

	public TextFragment(StringBuffer markedUpText, int textStartPos, int fragNum)
	{
		this.markedUpText = markedUpText;
		this.textStartPos = textStartPos;
		this.fragNum = fragNum;
	}

	void setScore(float score)
	{
		this.score = score;
	}

	public float getScore()
	{
		return score;
	}

	/**
	 * @param frag2
	 *        Fragment to be merged into this one
	 */
	public void merge(TextFragment frag2)
	{
		textEndPos = frag2.textEndPos;
		score = Math.max(score, frag2.score);
	}

	/**
	 * @param fragment
	 * @return true if this fragment follows the one passed
	 */
	public boolean follows(TextFragment fragment)
	{
		return textStartPos == fragment.textEndPos;
	}

	/**
	 * @return the fragment sequence number
	 */
	public int getFragNum()
	{
		return fragNum;
	}

	/*
	 * Returns the marked-up text for this text fragment
	 */
	public String toString()
	{
		return markedUpText.substring(textStartPos, textEndPos);
	}

}
