/*
 * Copyright (C) 2007 Chris Gilbert. All Rights Reserved.
 *
 * 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, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 *
 */
package com.arsdigita.forum;

import java.math.BigDecimal;

import com.arsdigita.bebop.Page;
import com.arsdigita.bebop.PageFactory;
import com.arsdigita.bebop.PageState;
import com.arsdigita.bebop.SimpleComponent;
import com.arsdigita.bebop.event.RequestEvent;
import com.arsdigita.bebop.event.RequestListener;
import com.arsdigita.bebop.parameters.BigDecimalParameter;
// import com.arsdigita.bebop.parameters.ParameterModel;
import com.arsdigita.forum.ui.Constants;
import com.arsdigita.forum.ui.ForumUserCompactView;
import com.arsdigita.kernel.permissions.PrivilegeDescriptor;
import com.arsdigita.toolbox.ui.ApplicationAuthenticationListener;
import com.arsdigita.xml.Element;

/**
 * Implementation of com.arsdigita.forum.PageBuilder that creates a
 * basic forum page with read access check.
 * Controls forum.ui classes to generate the xml and display the desired
 * elements (here esp. ForumUserCompactView).
 *
 * @author chris.gilbert@westsussex.gov.uk
 */
public class ForumPageBuilder implements PageBuilder, Constants {

	
    /**
     * 
     * @return
     */
    public Page buildPage() {

        Page page = PageFactory.buildPage(Constants.FORUM_XML_PREFIX,
                                          "Forum",
                                          "forumPage");

        //Output the title in an easy to find place
        page.add(new SimpleComponent(){
            public void generateXML(PageState state, Element parent) {
                Element nameElement = parent.newChildElement(
                                          Constants.FORUM_XML_PREFIX +
                                          ":name",
                                          Constants.FORUM_XML_NS);
                nameElement.setText(
                        ForumContext.getContext(state).getForum().getTitle());
                Element introductionElement = parent.newChildElement(
                                                  Constants.FORUM_XML_PREFIX +
                                                  ":introduction",
                                                  Constants.FORUM_XML_NS);
                introductionElement.setText(
                        ForumContext.getContext(state).getForum().getIntroduction());
            }
        });

        ForumUserCompactView forumComp = getForumComponent();
        page.add(forumComp);
        BigDecimalParameter topic = new BigDecimalParameter(TOPIC_PARAM);
        page.addGlobalStateParam(topic);
        // adds primitive READ descriptor, should be FORUM_READ instead in order
        // to allow forum specific READ access and forums not accessible to
        // the public, not logged-in user.
        // PrivilegeDescriptor.get(RESPOND_TO_THREAD_PRIVILEGE)
        // PrivilegeDescriptor.get(FORUM_READ_PRIVILEGE)
        page.addRequestListener(
                new ApplicationAuthenticationListener(PrivilegeDescriptor.READ));
        page.addRequestListener(new ForumPageRequestListener(topic, forumComp));
        return page;
    }


    /** 
     * 
     * @return
     */
    protected ForumUserCompactView getForumComponent() {
        return new ForumUserCompactView();
    }
	
    /**
     * Internal class
     */
    private static class ForumPageRequestListener implements RequestListener {

        private BigDecimalParameter m_categorySelection;
        private ForumUserCompactView m_forumComp;

        /**
         * Default Constructor
         * @param topicSelection
         * @param forumComp
         */
        public ForumPageRequestListener(BigDecimalParameter topicSelection,
                                        ForumUserCompactView forumComp) {
            m_categorySelection = topicSelection;
            m_forumComp = forumComp;
        }

        public void pageRequested(RequestEvent event) {

            PageState state = event.getPageState();
            ForumContext context = ForumContext.getContext(state);

            context.setCategorySelection(
                    (BigDecimal) event.getPageState().getValue(m_categorySelection));
        }
    }
}