/*
    * Copyright 2009-2010 Capgemini
    * 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 net.sourceforge.statelessfilter.utils;
  
  import java.security.SignatureException;
  
  import javax.servlet.http.Cookie;
  import javax.servlet.http.HttpServletRequest;
  
  import org.apache.commons.lang.StringUtils;
  
  /**
   * Cookie utility methods.
   * 
   * @author Nicolas Richeton
   * 
   */
  public class CookieUtils {
  
  	private CookieUtils() {
  	}
  
  	/**
  	 * Create a cookie.
  	 * 
  	 * @param name
  	 * @param content
  	 *            a valid cookie content string. Binary content should be Base64
  	 *            encoded. Text must be escaped to prevent issues with cookie
  	 *            attributes like path or maxage.
  	 * @return
  	 * @throws SignatureException
  	 */
  	public static Cookie createCookie(String name, String content)
  			throws SignatureException {
  		return createCookie(name, content, null, null, null, false, null);
  	}
  
  	/**
  	 * Create a cookie.
  	 * 
  	 * @param name
  	 * @param content
  	 *            a valid cookie content string. Binary content should be Base64
  	 *            encoded. Text must be escaped to prevent issues with cookie
  	 *            attributes like path or maxage.
  	 * @param domain
  	 * @param path
  	 * @param maxAge
  	 * @return
  	 * @throws SignatureException
  	 */
  	public static Cookie createCookie(String name, String content,
  			String domain, String path, Integer maxAge)
  			throws SignatureException {
  		return createCookie(name, content, domain, path, maxAge, false, null);
  	}
  
  	/**
  	 * Create and sign a cookie.
  	 * 
  	 * @param name
  	 * @param content
  	 *            a valid cookie content string. Binary content should be Base64
  	 *            encoded. Text must be escaped to prevent issues with cookie
  	 *            attributes like path or maxage.
  	 * @param domain
  	 * @param path
  	 * @param maxAge
  	 * @param sign
  	 * @param key
  	 * @return
  	 * @throws SignatureException
  	 */
  	public static Cookie createCookie(String name, String content,
  			String domain, String path, Integer maxAge, boolean sign, String key)
  			throws SignatureException {
  
  		String cContent = content;
  		if (sign && content != null) {
  			cContent = HmacUtils.signRFC2104HMAC(cContent, key, "|");
  		}
  		Cookie c = new Cookie(name, cContent);
  		if (domain != null) {
  			c.setDomain(domain);
  		}
 
 		if (path != null) {
 			c.setPath(path);
 		}
 
 		if (StringUtils.isEmpty(content)) {
 			c.setMaxAge(0);
 		} else if (maxAge != null) {
 			c.setMaxAge(maxAge.intValue());
 		}
 
 		return c;
 	}
 
 	/**
 	 * Get a cookie.
 	 * 
 	 * @param request
 	 * @param name
 	 * @return
 	 * @throws SignatureException
 	 */
 	public static Cookie getCookie(HttpServletRequest request, String name)
 			throws SignatureException {
 		return getCookie(request, name, false, null);
 	}
 
 	/**
 	 * Get a cookie and perform validity checks.
 	 * 
 	 * @param request
 	 * @param name
 	 * @param sign
 	 * @param key
 	 * @return
 	 * @throws SignatureException
 	 */
 	public static Cookie getCookie(HttpServletRequest request, String name,
 			boolean sign, String key) throws SignatureException {
 		Cookie[] cookies = request.getCookies();
 		if (cookies != null) {
 			for (int i = cookies.length - 1; i >= 0; i--) {
 				if (name.equals(cookies[i].getName())) {
 					if (sign && cookies[i].getValue() != null) {
 						if (HmacUtils.verifyRFC2104HMAC(cookies[i].getValue(),
 								key, "|") != null) {
 							return cookies[i];
 						}
 					} else {
 						return cookies[i];
 					}
 
 				}
 			}
 		}
 		return null;
 	}
 
 	/**
 	 * Remove signature from cookie content.
 	 * 
 	 * @param cookieValue
 	 *            signed cookie value
 	 * @return unsigned value.
 	 */
 	public static String removeCookieSignature(String cookieValue) {
 		if (cookieValue != null && cookieValue.contains("|")) {
 			return cookieValue.split("\\|")[0];
 		}
 
 		return null;
 	}
 }