Subversion Repositories SmartDukaan

package in.shop2020.serving.interceptors;

import in.shop2020.serving.services.UserSessionInfo;

import in.shop2020.serving.utils.DesEncrypter;

import java.util.HashMap;

import java.util.List;

import java.util.Map;

import javax.servlet.http.Cookie;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

import javax.servlet.http.HttpSession;

import org.apache.log4j.Logger;

import org.apache.struts2.ServletActionContext;

import org.apache.struts2.StrutsStatics;

import com.opensymphony.xwork2.ActionContext;

import com.opensymphony.xwork2.ActionInvocation;

import com.opensymphony.xwork2.interceptor.AbstractInterceptor;

import com.opensymphony.xwork2.interceptor.PreResultListener;

public class UserInterceptor extends AbstractInterceptor implements PreResultListener{

	public static final int SECONDS_IN_YEAR = 60*60*24*365; 

	private static final long serialVersionUID = -4125815700236506235L;

	private static Logger log = Logger.getLogger(UserInterceptor.class);

	public static final String USER_INFO_COOKIE_NAME = "uic";

	public static final String USER_ID_COOKIE_NAME = "uid";

	public static final String COOKIE_DECRYPTION_STRING = "shop2020";

	private Map<String, Cookie> cookiesMap = null;

	private Cookie userCookie = null;

	private DesEncrypter desEncrypter = new DesEncrypter(COOKIE_DECRYPTION_STRING);

	private Cookie userinfoCookie = null;

	private String cookieDomain = "";

	public void setCookieDomain(String cookieDomain) {

		this.cookieDomain = cookieDomain;

	}

	@Override

	public String intercept(ActionInvocation invocation) throws Exception {

		final Object action = invocation.getAction();

		log.debug("inside user intercepror");

        HttpServletRequest request = ServletActionContext.getRequest();

        HttpSession session = request.getSession(); // Do not remove it, session id is used for session tracking.

		createCookiesMap(request);

        // CreateUserInterceptor may have set the userinfo object in the request

        // itself. If we can get the userinfo object here, we don't need to

        // parse the cookies that came in with the request.

		UserSessionInfo userInfo = (UserSessionInfo) request.getAttribute(USER_INFO_COOKIE_NAME);

		userCookie = cookiesMap.get(UserInterceptor.USER_ID_COOKIE_NAME);

		userinfoCookie = cookiesMap.get(USER_INFO_COOKIE_NAME);

		if(userInfo == null ){

		    //Okay, we didn't get the userinfo object from the request. Time to parse the UIC cookie.

			if(userinfoCookie!=null){

				userInfo = UserSessionInfo.getUserSessionInfoFromCookieValue(userinfoCookie.getValue());

				if(userInfo.getUserId() == -1){

				    //This means that the cookie couldn't be parsed. So, we should remove the cookie.

				    expireUicCookie();

				    expireUidCookie();

				}

			} else {

			    //No UIC cookie too. Try the old UID cookie. This method is guaranteed  to return a userinfo object, cookie or not.

				userInfo = createAndGetSessionFromUIDCookie(session);

			}

		}

		//Set the request attribute for access by other interceptors.

		request.setAttribute(USER_INFO_COOKIE_NAME, userInfo);

		//Set the userinfo object for use by actions.

		if (action instanceof UserAware) {

        	UserAware sessionAction = (UserAware) action;

        	sessionAction.setSession(session);

        	sessionAction.setUserSessionInfo(userInfo);

        	sessionAction.setCookiesMap(cookiesMap);

        	sessionAction.setUserCookie(userCookie);

        	sessionAction.setCookieDomainName(cookieDomain);

        }

        // Ensure that the response of the action is presented to the pre-result

        // listened of this interceptor. We want to add the cookies there.

		invocation.addPreResultListener(this);

		return invocation.invoke();

	}

	@Override

	public void beforeResult(ActionInvocation invocation, String resultCode) {

		ActionContext ac = invocation.getInvocationContext();

		HttpServletResponse response = (HttpServletResponse) ac.get(StrutsStatics.HTTP_RESPONSE);

		addCookiesToResponse(invocation.getAction(), response);

	}	

	/**

	 * Adds cookies to the response object after the action has been executed.

	 * 

	 * @param action

	 * @param response

	 */

	private void addCookiesToResponse(Object action, HttpServletResponse response) {

	    log.debug("Setting cookies in response");

		if (action instanceof UserAware) {

			List<Cookie> cookies = ((UserAware) action).getCookies();

			if (cookies != null) {

				for (Cookie cookie : cookies) {

				    log.debug("Adding cookie " + cookie.getName() + " to the response");

					response.addCookie(cookie);

				}

			}

		}

	}

    /**

     * Expires the UID cookie if the domain is not set or is set as the empty

     * domain. Creates a new UID cookie with the cookie domain set.

     * 

     * This is mostly to handle legacy issue wherein we were not setting the

     * cookie domain explicitly to .saholic.com and different cookies were set

     * for saholic.com and www.saholic.com.

     * 

     * @param request

     */

	private void createCookiesMap(HttpServletRequest request) {

		cookiesMap  = new HashMap<String, Cookie>();

		Cookie[] cookies = request.getCookies();

		if(cookies==null)

			return;

		for (Cookie cookie : cookies) {

			if (cookie.getName().equals(UserInterceptor.USER_ID_COOKIE_NAME)) {

				if (cookie.getDomain() == null || cookie.getDomain().isEmpty()

						|| !cookie.getDomain().equals(this.cookieDomain)) 

				{

					if (!cookieDomain.isEmpty()) {

						cookie.setMaxAge(0);

						Cookie newUserCookie = new Cookie(UserInterceptor.USER_ID_COOKIE_NAME, cookie.getValue());

						newUserCookie.setMaxAge(SECONDS_IN_YEAR); // one year

						newUserCookie.setPath("/");

						newUserCookie.setDomain(cookieDomain);

						HttpServletResponse response = ServletActionContext.getResponse();

						response.addCookie(newUserCookie);

						response.addCookie(cookie);

					} else {

					    log.error("cookieDomain not set");

					}

				}

			}

		    cookiesMap.put(cookie.getName(), cookie);

		}

	}

    /**

     * Creates and gets session information from the UID cookie. This should be

     * called only when the required information couldn't be had from the UIC

     * cookie.

     * 

     * It also expires the UID cookie if it can't parse the cookie value.

     * 

     * @param session

     * @return A user session info object.

     */

	private UserSessionInfo createAndGetSessionFromUIDCookie(HttpSession session) {

		userCookie = (Cookie) cookiesMap.get(UserInterceptor.USER_ID_COOKIE_NAME);

		UserSessionInfo userInfo = null;

		if(userCookie != null){

			String uidString = userCookie.getValue();

			if(uidString != null){

				try {

					Long receivedUID = Long.parseLong(desEncrypter.decrypt(uidString));

                    log.info("Invalid session with user cookie : " + receivedUID);

					userInfo = new UserSessionInfo(receivedUID, session.getId());

					if(userInfo.getUserId() == -1){

					    log.error("The User for the UID cookie has been deleted in our database. So cleaning up the UID cookie.");

					    expireUidCookie();

					}

				} catch (NumberFormatException nfe) {

					log.error("The UID cookie contains an unparseable userID");

					expireUidCookie();

					userInfo = new UserSessionInfo();

				}

			}

		} else{

		    log.info("Invalid session without user cookie.");

		    userInfo = new UserSessionInfo();

		}

		return userInfo;

	}

	/**

	 * Expires the UIC cookie.

	 */

    private void expireUicCookie() {

        Cookie newUserCookie = new Cookie(UserInterceptor.USER_INFO_COOKIE_NAME, "-1"); //The value here is immaterial

        newUserCookie.setMaxAge(0);                     // Expire this cookie now

        newUserCookie.setPath("/");

        newUserCookie.setDomain(cookieDomain);

        HttpServletResponse response = ServletActionContext.getResponse();

        response.addCookie(newUserCookie);

    }	

    /**

     * Expires the UID cookie.

     */

    private void expireUidCookie() {

        Cookie newUserCookie = new Cookie(UserInterceptor.USER_ID_COOKIE_NAME, "-1"); //The value here is immaterial

        newUserCookie.setMaxAge(0);                     // Expire this cookie now

        newUserCookie.setPath("/");

        newUserCookie.setDomain(cookieDomain);

        HttpServletResponse response = ServletActionContext.getResponse();

        response.addCookie(newUserCookie);

    }

}