MessageForumsFilePickerServlet.java

/**********************************************************************************
 * $URL: https://source.sakaiproject.org/svn/msgcntr/trunk/messageforums-app/src/java/org/sakaiproject/tool/messageforums/MessageForumsFilePickerServlet.java $
 * $Id: MessageForumsFilePickerServlet.java 9227 2006-05-15 15:02:42Z cwen@iupui.edu $
 ***********************************************************************************
 *
 * Copyright (c) 2003, 2004, 2005, 2006, 2007, 2008 The Sakai Foundation
 *
 * Licensed under the Educational Community 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.opensource.org/licenses/ECL-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.sakaiproject.tool.messageforums;

import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.net.URLEncoder;
import java.util.Enumeration;

import javax.servlet.RequestDispatcher;
import javax.servlet.ServletConfig;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.sakaiproject.site.api.SiteService;
import org.sakaiproject.tool.api.ToolSession;
import org.sakaiproject.tool.cover.SessionManager;
import org.sakaiproject.tool.api.ActiveTool;
import org.sakaiproject.tool.api.Tool;
import org.sakaiproject.tool.cover.ActiveToolManager;
import org.sakaiproject.api.app.messageforums.ui.DiscussionForumManager;
import org.sakaiproject.component.cover.ComponentManager;
import org.sakaiproject.entitybroker.EntityReference;
import org.sakaiproject.entitybroker.access.HttpServletAccessProvider;
import org.sakaiproject.entitybroker.access.HttpServletAccessProviderManager;
import org.sakaiproject.exception.IdUnusedException;
import org.sakaiproject.jsf.util.JsfTool;
import org.sakaiproject.util.Web;
import org.sakaiproject.tool.api.ToolException;

/**
 * @author Chen Wen
 * @version $Id$
 * 
 */
public class MessageForumsFilePickerServlet extends JsfTool  implements HttpServletAccessProvider {
    private static final String HELPER_EXT = ".helper";

    private static final String HELPER_SESSION_PREFIX = "session.";
    
    private boolean initComplete = false;
    private SiteService siteService;
    private HttpServletAccessProviderManager accessProviderManager;
    private DiscussionForumManager forumManager;

    protected void dispatch(HttpServletRequest req, HttpServletResponse res) throws ServletException, IOException {
        // NOTE: this is a simple path dispatching, taking the path as the view
        // id = jsp file name for the view,
        // with default used if no path and a path prefix as configured.
        // TODO: need to allow other sorts of dispatching, such as pulling out
        // drill-down ids and making them
        // available to the JSF

        // build up the target that will be dispatched to
        String target = req.getPathInfo();

        // see if we have a helper request
        if (sendToHelper(req, res, target)) {
            return;
        }

        // see if we have a resource request - i.e. a path with an extension,
        // and one that is not the JSF_EXT
        if (isResourceRequest(target)) {
            // get a dispatcher to the path
            RequestDispatcher resourceDispatcher = getServletContext().getRequestDispatcher(target);
            if (resourceDispatcher != null) {
                resourceDispatcher.forward(req, res);
                return;
            }
        }

        if ("Title".equals(req.getParameter("panel"))) {
            // This allows only one Title JSF for each tool
            target = "/title.jsf";
        }

        else {
            ToolSession session = SessionManager.getCurrentToolSession();

            if (target == null || "/".equals(target)) {
                target = computeDefaultTarget(true);

                // make sure it's a valid path
                if (!target.startsWith("/")) {
                    target = "/" + target;
                }

                // now that we've messed with the URL, send a redirect to make
                // it official
                res.sendRedirect(Web.returnUrl(req, target));
                return;
            }

            // see if we want to change the specifically requested view
            String newTarget = redirectRequestedTarget(target);

            // make sure it's a valid path
            if (!newTarget.startsWith("/")) {
                newTarget = "/" + newTarget;
            }

            if (!newTarget.equals(target)) {
                // now that we've messed with the URL, send a redirect to make
                // it official
                res.sendRedirect(Web.returnUrl(req, newTarget));
                return;
            }
            target = newTarget;

            // store this
            if (m_defaultToLastView) {
                session.setAttribute(LAST_VIEW_VISITED, target);
            }
        }

        // add the configured folder root and extension (if missing)
        target = m_path + target;

        // add the default JSF extension (if we have no extension)
        int lastSlash = target.lastIndexOf("/");
        int lastDot = target.lastIndexOf(".");
        if (lastDot < 0 || lastDot < lastSlash) {
            target += JSF_EXT;
        }

        // set the information that can be removed from return URLs
        req.setAttribute(URL_PATH, m_path);
        req.setAttribute(URL_EXT, ".jsp");

        // set the sakai request object wrappers to provide the native, not
        // Sakai set up, URL information
        // - this assures that the FacesServlet can dispatch to the proper view
        // based on the path info
        req.setAttribute(Tool.NATIVE_URL, Tool.NATIVE_URL);

        // TODO: Should setting the HTTP headers be moved up to the portal level
        // as well?
        res.setContentType("text/html; charset=UTF-8");
        res.addDateHeader("Expires", System.currentTimeMillis() - (1000L * 60L * 60L * 24L * 365L));
        res.addDateHeader("Last-Modified", System.currentTimeMillis());
        res.addHeader("Cache-Control", "no-store, no-cache, must-revalidate, max-age=0, post-check=0, pre-check=0");
        res.addHeader("Pragma", "no-cache");

        // dispatch to the target
        RequestDispatcher dispatcher = getServletContext().getRequestDispatcher(target);
        dispatcher.forward(req, res);

        // restore the request object
        req.removeAttribute(Tool.NATIVE_URL);
        req.removeAttribute(URL_PATH);
        req.removeAttribute(URL_EXT);
    }

    protected boolean sendToHelper(HttpServletRequest req, HttpServletResponse res, String target) 
    throws ToolException
    {
        String path = req.getPathInfo();
        if (path == null)
            path = "/";

        // if synoptic helper is obscuring add attachment helper, remove it
        final int helperIndex = path.indexOf("sakai.filepicker");
        
        // filepicker helper should be first part of path
        if (helperIndex > 1 ) {
        	path = path.substring(helperIndex-1);
        	target = path;
        }
        
        // 
        // 0 parts means the path was just "/", otherwise parts[0] = "",
        // parts[1] = item id, parts[2] if present is "edit"...
        String[] parts = path.split("/");

        if (parts.length < 2) {
            return false;
        }
/*        if (parts.length < 3) {
//          return false;
     }*/
        
        if (!parts[1].endsWith(HELPER_EXT)) {
            return false;
        }
        /*
        if (!parts[2].endsWith(HELPER_EXT)) {
          return false;
        }
        */
        ToolSession toolSession = SessionManager.getCurrentToolSession();

        Enumeration params = req.getParameterNames();
        while (params.hasMoreElements()) {
            String paramName = (String) params.nextElement();
            if (paramName.startsWith(HELPER_SESSION_PREFIX)) {
                String attributeName = paramName.substring(HELPER_SESSION_PREFIX.length());
                toolSession.setAttribute(attributeName, req.getParameter(paramName));
            }
        }

        // calc helper id
        int posEnd = parts[1].lastIndexOf(".");
        ////int posEnd = parts[2].lastIndexOf(".");

        String helperId = target.substring(1, posEnd + 1);
        ////String helperId = parts[2].substring(0, posEnd);
        ActiveTool helperTool = ActiveToolManager.getActiveTool(helperId);

        if (toolSession.getAttribute(helperTool.getId() + Tool.HELPER_DONE_URL) == null
                && !target.equals("/sakai.filepicker.helper")) {
            toolSession.setAttribute(helperTool.getId() + Tool.HELPER_DONE_URL, req.getContextPath() + req.getServletPath() + computeDefaultTarget(true));
        }

        String context = req.getContextPath() + req.getServletPath() + Web.makePath(parts, 1, 2);
        ////String context = req.getContextPath() + req.getServletPath() + Web.makePath(parts, 2, 3);
        String toolPath = Web.makePath(parts, 2, parts.length);
        ////String toolPath = Web.makePath(parts, 3, parts.length);
        helperTool.help(req, res, context, toolPath);

        return true; // was handled as helper call
    }

    protected String computeDefaultTarget(boolean lastVisited) {
        // setup for the default view as configured
        String target = "/" + m_default;

        // if we are doing lastVisit and there's a last-visited view, for this
        // tool placement / user, use that
        if (lastVisited) {
            ToolSession session = SessionManager.getCurrentToolSession();
            String last = (String) session.getAttribute(LAST_VIEW_VISITED);
            if (last != null) {
                target = last;
            }
        }

        return target;
    }

    /**
     * Initialize the servlet.
     * 
     * @param config
     *        The servlet config.
     * @throws ServletException
     */
    public void init(ServletConfig config) throws ServletException {
      super.init(config);
      
      try {
        //load service level dependecies from the ComponentManager
        siteService = (SiteService) ComponentManager.get("org.sakaiproject.site.api.SiteService");
        accessProviderManager = (HttpServletAccessProviderManager) ComponentManager
          .get("org.sakaiproject.entitybroker.access.HttpServletAccessProviderManager");
        forumManager = (DiscussionForumManager) ComponentManager
          .get("org.sakaiproject.api.app.messageforums.ui.DiscussionForumManager");
        
        //register forum Entity prefixes for direct servlet request handling
        if (accessProviderManager != null) {
          accessProviderManager.registerProvider("forum_topic", this);
          accessProviderManager.registerProvider("forum", this);
          accessProviderManager.registerProvider("forum_message", this);
        }
        //mark initialization of dependecies as complete
        if (siteService != null && forumManager != null)
          initComplete = true;
      } catch (Exception e) {
        e.printStackTrace();
      }
    }
    
    
    public void handleAccess(HttpServletRequest req, HttpServletResponse res, EntityReference ref) {
        //don't bother if the user is not logged in
        if (req.getRemoteUser() == null) {
            try {
                String url = req.getRequestURL().toString();
                String context = req.getContextPath();
                String prefix = url.substring(0,url.lastIndexOf(context));
      
                res.sendRedirect(prefix + "/authn/login?url="
                                 + URLEncoder.encode(req.getRequestURL().toString(), "UTF-8"));
                return;
            }
            catch (UnsupportedEncodingException e) {
                e.printStackTrace();
            }
            catch (IOException e) {
                e.printStackTrace();
            }
        }
      
        String[] parts = req.getPathInfo().split("/");
        //ensure we have our dependencies and something reassembling proper input
        if (initComplete && parts.length > 2) {
            String context = "";
            if ("forum_topic".equals(parts[1]))
              context = forumManager.getContextForTopicById(Long.valueOf(parts[2]));
            else if ("forum".equals(parts[1]))
              context = forumManager.getContextForForumById(Long.valueOf(parts[2]));
            else if ("forum_message".equals(parts[1]))
              context = forumManager.getContextForMessageById(Long.valueOf(parts[2]));

            String placementId = "";
            String target = "";
    
            //Calculate the placement for the Entity... if you know of a better way, please
            //replace this!
            try {
                if (siteService.getSite(context).getToolForCommonId("sakai.forums") != null) {
                    placementId = siteService.getSite(context)
                                         .getToolForCommonId("sakai.forums").getId();
                }
                else {
                    placementId = siteService.getSite(context)
                                         .getToolForCommonId("sakai.messagecenter").getId();
                }
            }
            catch (IdUnusedException iue) {
                iue.printStackTrace();
            }
    
            //TODO: I've tried (and failed) a number of things here to try to get this to work
            //without a redirect using a block of setting all the placement and session things
            //into the the threadlocal manager here resulted in the closest thing... rendered
            //the page, but links were broken, might be doable with more time or fresh eyes
            //though.

            //direct the request to the proper 'direct' view with needed parameters
            if ("forum_topic".equals(parts[1])) {
                req.setAttribute("topicId", parts[2]);
                target = "/jsp/discussionForum/message/dfAllMessagesDirect.jsf?topicId="
                       + parts[2] + "&placementId=" + placementId;
            }
            else if ("forum".equals(parts[1])) {
                target = "/jsp/discussionForum/forum/dfForumDirect.jsf?forumId="
                       + parts[2] + "&placementId=" + placementId;
            }
            else if ("forum_message".equals(parts[1])) {
                target = "/jsp/discussionForum/message/dfViewMessageDirect.jsf?messageId="
                       + parts[2] + "&placementId=" + placementId + "&topicId="
                       + forumManager.getMessageById(Long.valueOf(parts[2])).getTopic().getId()
                       + "&forumId=" + forumManager.ForumIdForMessage(Long.valueOf(parts[2]));
            }

            // dispatch to the target
            RequestDispatcher dispatcher = getServletContext().getRequestDispatcher(target);
            try {
                dispatcher.forward(req, res);
            }
            catch (ServletException e) {
                e.printStackTrace();
            }
            catch (IOException e) {
                e.printStackTrace();
            }        
        }
    }
}