/*
 * Copyright 1999-2002,2004 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.
 */


package org.apache.struts.webapp.example2;


import java.lang.reflect.InvocationTargetException;
import java.util.Locale;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import org.apache.commons.beanutils.PropertyUtils;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.struts.action.Action;
import org.apache.struts.action.ActionForm;
import org.apache.struts.action.ActionForward;
import org.apache.struts.action.ActionMapping;
import org.apache.struts.util.MessageResources;


/**
 * Implementation of <strong>Action</strong> that validates and creates or
 * updates the mail subscription entered by the user.
 *
 * @author Craig R. McClanahan
 * @version $Rev: 54936 $ $Date: 2004-10-16 18:57:09 +0100 (Sat, 16 Oct 2004) $
 */

public final class SaveSubscriptionAction extends Action {


    // ----------------------------------------------------- Instance Variables


    /**
     * The <code>Log</code> instance for this application.
     */
    private Log log =
        LogFactory.getLog("org.apache.struts.webapp.Example");


    // --------------------------------------------------------- Public Methods


    /**
     * Process the specified HTTP request, and create the corresponding HTTP
     * response (or forward to another web component that will create it).
     * Return an <code>ActionForward</code> instance describing where and how
     * control should be forwarded, or <code>null</code> if the response has
     * already been completed.
     *
     * @param mapping The ActionMapping used to select this instance
     * @param form The optional ActionForm bean for this request (if any)
     * @param request The HTTP request we are processing
     * @param response The HTTP response we are creating
     *
     * @exception Exception if the application business logic throws
     *  an exception
     */
    public ActionForward execute(ActionMapping mapping,
				 ActionForm form,
				 HttpServletRequest request,
				 HttpServletResponse response)
	throws Exception {

	// Extract attributes and parameters we will need
	Locale locale = getLocale(request);
	MessageResources messages = getResources(request);
	HttpSession session = request.getSession();
	SubscriptionForm subform = (SubscriptionForm) form;
	String action = subform.getAction();
	if (action == null) {
	    action = "?";
        }
        if (log.isDebugEnabled()) {
            log.debug("SaveSubscriptionAction:  Processing " + action +
                      " action");
        }

	// Is there a currently logged on user?
	User user = (User) session.getAttribute(Constants.USER_KEY);
	if (user == null) {
            if (log.isTraceEnabled()) {
                log.trace(" User is not logged on in session "
                          + session.getId());
            }
	    return (mapping.findForward("logon"));
        }

	// Was this transaction cancelled?
	if (isCancelled(request)) {
            if (log.isTraceEnabled()) {
                log.trace(" Transaction '" + action +
                          "' was cancelled");
            }
            session.removeAttribute(Constants.SUBSCRIPTION_KEY);
	    return (mapping.findForward("success"));
	}

	// Is there a related Subscription object?
	Subscription subscription =
	  (Subscription) session.getAttribute(Constants.SUBSCRIPTION_KEY);
        if ("Create".equals(action)) {
            if (log.isTraceEnabled()) {
                log.trace(" Creating subscription for mail server '" +
                          subform.getHost() + "'");
            }
            subscription =
                user.createSubscription(subform.getHost());
        }
	if (subscription == null) {
            if (log.isTraceEnabled()) {
                log.trace(" Missing subscription for user '" +
                          user.getUsername() + "'");
            }
	    response.sendError(HttpServletResponse.SC_BAD_REQUEST,
	                       messages.getMessage("error.noSubscription"));
	    return (null);
	}

	// Was this transaction a Delete?
	if (action.equals("Delete")) {
            if (log.isTraceEnabled()) {
                log.trace(" Deleting mail server '" +
                          subscription.getHost() + "' for user '" +
                          user.getUsername() + "'");
            }
            user.removeSubscription(subscription);
	    session.removeAttribute(Constants.SUBSCRIPTION_KEY);
            try {
                UserDatabase database = (UserDatabase)
                    servlet.getServletContext().
                    getAttribute(Constants.DATABASE_KEY);
                database.save();
            } catch (Exception e) {
                log.error("Database save", e);
            }
	    return (mapping.findForward("success"));
	}

	// All required validations were done by the form itself

	// Update the persistent subscription information
        if (log.isTraceEnabled()) {
            log.trace(" Populating database from form bean");
        }
        try {
            PropertyUtils.copyProperties(subscription, subform);
        } catch (InvocationTargetException e) {
            Throwable t = e.getTargetException();
            if (t == null)
                t = e;
            log.error("Subscription.populate", t);
            throw new ServletException("Subscription.populate", t);
        } catch (Throwable t) {
            log.error("Subscription.populate", t);
            throw new ServletException("Subscription.populate", t);
        }

        try {
            UserDatabase database = (UserDatabase)
                servlet.getServletContext().
                getAttribute(Constants.DATABASE_KEY);
            database.save();
        } catch (Exception e) {
            log.error("Database save", e);
        }

	// Remove the obsolete form bean and current subscription
	if (mapping.getAttribute() != null) {
            if ("request".equals(mapping.getScope()))
                request.removeAttribute(mapping.getAttribute());
            else
                session.removeAttribute(mapping.getAttribute());
        }
	session.removeAttribute(Constants.SUBSCRIPTION_KEY);

	// Forward control to the specified success URI
        if (log.isTraceEnabled()) {
            log.trace(" Forwarding to success page");
        }
	return (mapping.findForward("success"));

    }


}
