package net.sourceforge.stripes.util;

import java.net.MalformedURLException;
import java.net.URL;

/**
 * UrlParser
 * 
 * @author Christian Schwanke
 */
public class UrlParser {
	private static final String JSESSIONID_NAME = ";jsessionid";

	/**
	 * Parses the given url into a HttpUrlInfo instance
	 * 
	 * @param urlValue
	 *            The url to parse
	 * @return a HttpUrlInfo instance containing the various parts of the url
	 * @throws MalformedURLException
	 *             If the given string cannot be parsed
	 */
	public static HttpUrlInfo parseUrl(String urlValue)
			throws MalformedURLException {
		HttpUrlInfo urlInfo = new HttpUrlInfo();
		if (urlValue != null) {
			URL url = null;
			if (urlValue.startsWith("http")) {
				url = new URL(urlValue);
				urlInfo.setProtocol(url.getProtocol());
				urlInfo.setHost(url.getHost());
				urlInfo.setPort(url.getPort());
			} else {
				url = new URL("http://dummy" + urlValue);
			}
			urlInfo.setQuery(url.getQuery());
			urlInfo.setRef(url.getRef());
			urlInfo.setPath(removeSession(url.getPath()));
			urlInfo.setSession(extractSession(url.getPath()));
		}
		return urlInfo;
	}

	/**
	 * Extracts the jsessionid from the given url without the leading ;
	 * character
	 * 
	 * @param url
	 *            The url to work with
	 * @return The jsessionid found in the url or null if no jsessionid is
	 *         present
	 */
	public static String extractSession(String url) {
		if (url != null && url.contains(JSESSIONID_NAME)) {
			int end = url.length();
			if (url.contains("?")) {
				end = url.indexOf("?");
			} else if (url.contains("#")) {
				end = url.indexOf("#");
			}
			return url.substring(url.indexOf(JSESSIONID_NAME) + 1, end);
		}
		return null;
	}

	/**
	 * Strips an existing jsession part from the given URL. If no sessionid is
	 * present, the url is returned unchanged
	 * 
	 * @param url
	 *            The url to manipulate
	 * @return The given url without the jsessionid
	 */
	public static String removeSession(String url) {
		if (url != null && url.contains(JSESSIONID_NAME)) {
			int end = url.length();
			if (url.contains("?")) {
				end = url.indexOf("?");
			} else if (url.contains("#")) {
				end = url.indexOf("#");
			}
			String endPart = url.substring(end + 1);
			return url.substring(0, url.indexOf(JSESSIONID_NAME)) + endPart;
		}
		return url;
	}
}