/*
Wotonomy: OpenStep design patterns for pure Java applications.
Copyright (C) 2000 Blacksmith, Inc.

This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.

This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public
License along with this library; if not, see http://www.gnu.org
*/

package net.wotonomy.web;

/**
 * An implementation of WORequestHandler that dispatches Component actions.
 *
 * @author michael@mpowers.net
 * @author $Author: cgruber $
 * @version $Revision: 905 $
 */
public class WOComponentRequestHandler extends WORequestHandler {
	public WOResponse handleRequest(WORequest aRequest) {
		WOApplication application = aRequest.application();
		WOContext context = WOContext.contextWithRequest(aRequest);
		WOResponse response = null;

		// no concurrent access is allowed to a user's session:
		// a user/browser/machine with multiple requests will have to wait
		synchronized (aRequest.request.getSession()) {
			try {
				application.awake();

				WOSession session = null;
				/*
				 * // the NeXT way String sessionID = aRequest.sessionID(); if ( sessionID !=
				 * null ) { session = application.restoreSessionWithID( sessionID, context ); if
				 * ( session == null ) { response =
				 * application.handleSessionRestorationErrorInContext( context ); } } else {
				 * session = application.createSessionForRequest( aRequest ); if ( session ==
				 * null ) { response = application.handleSessionCreationErrorInContext( context
				 * ); } else { session.setContext( context ); } }
				 */
				// the servlet way
				String sessionID = aRequest.sessionID();
				if (sessionID != null) {
					session = application.restoreSessionWithID(sessionID, context);
				}

				if (session == null) {
					session = application.createSessionForRequest(aRequest);
					if (session == null) {
						response = application.handleSessionCreationErrorInContext(context);
					} else {
						session.setContext(context);
					}
				}

				context.setSession(session);

				session.awake();

				if (response == null) {

					WOComponent page;
					String contextID = aRequest.contextID();

					if (contextID != null) {
						page = session.restorePageForContextID(contextID);
					} else {
						page = application.pageWithName(aRequest.pageName(), context);
					}

					if (page == null) {
						// FIXME: should we call this a restoration error, or do we
						// allow a bookmark with an expired context id to resume gracefully?
						page = application.pageWithName(aRequest.pageName(), context);
						// !response = application.handlePageRestorationErrorInContext( context );
					}
					// !else
					{
						context.pushElement(page); // ? needed?
						page.ensureAwakeInContext(context); // ? shouldn't this be in WOApplication?

						// only take values from request if there are values in the request
						System.out
								.println("should I takeValuesFromRequest ? " + (aRequest.formValueKeys().count() > 0));
						if (aRequest.formValueKeys().count() > 0) {
							application.takeValuesFromRequest(aRequest, context);
						}

						// only invoke action if there is a sender id to invoke
						WOActionResults result;
						System.out.println("senderID: " + aRequest.senderID());
						if (aRequest.senderID() != null) {
							result = application.invokeAction(aRequest, context);
						} else {
							result = null;
						}

						if (result == null || result == page) // same page is returned
						{
							result = page;

							// generate response
							response = new WOResponse();
							application.appendToResponse(response, context);
							page.sleep();
						} else // different page is returned
						if (result instanceof WOComponent) {
							page.sleep();
							page = (WOComponent) result;
							page.ensureAwakeInContext(context);
							context.popElement(); // removes page
							context.pushElement(page);

							// generate response
							response = new WOResponse();
							application.appendToResponse(response, context);
							page.sleep();
						} else // WOResponse was returnd
						{
							response = (WOResponse) result;
						}

						context.popElement();
						session.sleep();
						session.savePage(page);
						session.setContext(null);
						application.saveSessionForContext(context);
					}
				}
			} catch (Throwable t) {
				response = application.handleException(t, context);
			}

			application.sleep();
		}
		return response;
	}
}

/*
 * $Log$ Revision 1.2 2006/02/19 01:44:02 cgruber Add xmlrpc files Remove jclark
 * and replace with dom4j and javax.xml.sax stuff Re-work dependencies and
 * imports so it all compiles.
 *
 * Revision 1.1 2006/02/16 13:22:22 cgruber Check in all sources in
 * eclipse-friendly maven-enabled packages.
 *
 * Revision 1.8 2003/08/07 00:15:15 chochos general cleanup (mostly removing
 * unused imports)
 *
 * Revision 1.7 2003/01/17 20:34:57 mpowers Better handling for components and
 * parents in the context's element stack.
 *
 * Revision 1.6 2003/01/15 19:50:49 mpowers Fixed issues with WOSession and
 * Serializable. Can now persist sessions between classloaders (hot swap of
 * class impls).
 *
 * Revision 1.4 2003/01/14 15:51:09 mpowers No longer calling takeValues or
 * invokeAction if there are no request params
 *
 * Revision 1.3 2003/01/13 22:24:34 mpowers Request-response cycle is working
 * with session and page persistence.
 *
 * Revision 1.1 2003/01/09 16:13:59 mpowers Implemented
 * WOComponentRequestHandler: Bringing the request-response cycle more into
 * conformance.
 *
 * Revision 1.2 2002/12/17 14:57:44 mpowers Minor corrections to WORequests's
 * parsing, and updated javadocs.
 *
 * Revision 1.1.1.1 2000/12/21 15:53:19 mpowers Contributing wotonomy.
 *
 * Revision 1.2 2000/12/20 16:25:50 michael Added log to all files.
 *
 *
 */