/*******************************************************************************
 * Copyright (c) 2010, 2013 Tasktop Technologies and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *     Tasktop Technologies - initial API and implementation
 *******************************************************************************/

package org.eclipse.mylyn.commons.core;

import java.io.IOException;
import java.io.StringReader;
import java.text.ParseException;

import org.eclipse.mylyn.commons.core.HtmlStreamTokenizer.Token;
import org.eclipse.mylyn.internal.commons.core.Html2TextReader;

/**
 * @author Steffen Pingel
 * @since 3.5
 */
public class HtmlUtil {

	/**
	 * Strips HTML tags from a text.
	 * 
	 * @param htmlText
	 *            a string that contains HTML tags
	 * @return htmlText converted to plain text
	 * @throws IOException
	 *             thrown if a parsing error occurs
	 */
	public static String toText(String htmlText) throws IOException {
		Html2TextReader reader = new Html2TextReader(new StringReader(htmlText));
		try {
			int c;
			StringBuffer sb = new StringBuffer(htmlText.length());
			while ((c = reader.read()) != -1) {
				sb.append((char) c);
			}
			return sb.toString();
		} finally {
			reader.close();
		}
	}

	/**
	 * @since 3.7
	 */
	public static String getTextContent(HtmlStreamTokenizer tokenizer) throws IOException, ParseException {
		StringBuilder sb = new StringBuilder();
		for (Token token = tokenizer.nextToken(); token.getType() != Token.EOF; token = tokenizer.nextToken()) {
			if (token.getType() == Token.TEXT) {
				sb.append(token.toString().trim());
				sb.append(" "); //$NON-NLS-1$
			} else if (token.getType() == Token.COMMENT) {
				// ignore
			} else {
				break;
			}
		}
		return sb.toString().trim();
	}

}