/*
 * Copyright 1999-2001,2004 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.example;


import java.lang.reflect.InvocationTargetException;
import java.util.Locale;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpSession;
import javax.servlet.http.HttpServletResponse;
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 populates an instance of
 * <code>SubscriptionForm</code> from the currently specified subscription.
 *
 * @author Craig R. McClanahan
 * @version $Rev: 54936 $ $Date: 2004-10-16 18:57:09 +0100 (Sat, 16 Oct 2004) $
 */

public final class EditSubscriptionAction 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 we will need
	Locale locale = getLocale(request);
	MessageResources messages = getResources(request);
	HttpSession session = request.getSession();
	String action = request.getParameter("action");
	if (action == null) {
	    action = "Create";
        }
	String host = request.getParameter("host");
        if (log.isDebugEnabled()) {
            log.debug("EditSubscriptionAction:  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"));
	}

	// Identify the relevant subscription
	Subscription subscription =
            user.findSubscription(request.getParameter("host"));
	if ((subscription == null) && !action.equals("Create")) {
            if (log.isTraceEnabled()) {
                log.trace(" No subscription for user " +
                          user.getUsername() + " and host " + host);
            }
	    return (mapping.findForward("failure"));
	}
        if (subscription != null) {
            session.setAttribute(Constants.SUBSCRIPTION_KEY, subscription);
        }

	// Populate the subscription form
	if (form == null) {
            if (log.isTraceEnabled()) {
                log.trace(" Creating new SubscriptionForm bean under key "
                          + mapping.getAttribute());
            }
	    form = new SubscriptionForm();
            if ("request".equals(mapping.getScope())) {
                request.setAttribute(mapping.getAttribute(), form);
            } else {
                session.setAttribute(mapping.getAttribute(), form);
            }
	}
	SubscriptionForm subform = (SubscriptionForm) form;
	subform.setAction(action);
        if (!action.equals("Create")) {
            if (log.isTraceEnabled()) {
                log.trace(" Populating form from " + subscription);
            }
            try {
                PropertyUtils.copyProperties(subform, subscription);
                subform.setAction(action);
            } catch (InvocationTargetException e) {
                Throwable t = e.getTargetException();
                if (t == null)
                    t = e;
                log.error("SubscriptionForm.populate", t);
                throw new ServletException("SubscriptionForm.populate", t);
            } catch (Throwable t) {
                log.error("SubscriptionForm.populate", t);
                throw new ServletException("SubscriptionForm.populate", t);
            }
        }

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

    }


}
