/*
    * Copyright (C) 2003-2009 eXo Platform SAS.
    *
    * This program is free software; you can redistribute it and/or
    * modify it under the terms of the GNU Affero General Public License
    * as published by the Free Software Foundation; either version 3
    * of the License, or (at your option) any later version.
    *
    * This program 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 General Public License for more details.
   *
   * You should have received a copy of the GNU General Public License
   * along with this program; if not, see<http://www.gnu.org/licenses/>.
   */
  package org.exoplatform.wcm.connector.fckeditor;
  
  import java.io.OutputStreamWriter;
  import java.net.URL;
  import java.net.URLConnection;
  import java.text.DateFormat;
  import java.text.SimpleDateFormat;
  import java.util.ArrayList;
  import java.util.Date;
  import java.util.List;
  import java.util.Locale;
  import java.util.MissingResourceException;
  import java.util.Random;
  import java.util.ResourceBundle;
  
  import javax.ws.rs.GET;
  import javax.ws.rs.Path;
  import javax.ws.rs.QueryParam;
  import javax.ws.rs.core.CacheControl;
  import javax.ws.rs.core.MediaType;
  import javax.ws.rs.core.Response;
  import javax.xml.parsers.DocumentBuilder;
  import javax.xml.parsers.DocumentBuilderFactory;
  import javax.xml.transform.dom.DOMSource;
  
  import org.apache.commons.io.IOUtils;
  import org.exoplatform.application.gadget.Gadget;
  import org.exoplatform.application.gadget.GadgetRegistryService;
  import org.exoplatform.application.registry.Application;
  import org.exoplatform.application.registry.ApplicationCategory;
  import org.exoplatform.application.registry.ApplicationRegistryService;
  import org.exoplatform.container.PortalContainer;
  import org.exoplatform.container.component.RequestLifeCycle;
  import org.exoplatform.container.xml.InitParams;
  import org.exoplatform.portal.config.model.ApplicationType;
  import org.exoplatform.portal.gadget.core.ExoDefaultSecurityTokenGenerator;
  import org.exoplatform.services.log.ExoLogger;
  import org.exoplatform.services.log.Log;
  import org.exoplatform.services.rest.resource.ResourceContainer;
  import org.exoplatform.services.security.ConversationState;
  import org.exoplatform.services.wcm.utils.WCMCoreUtils;
  import org.json.JSONObject;
  import org.w3c.dom.Document;
  import org.w3c.dom.Element;
  
  /**
   * Instantiates a new gadget connector.
   *
   * @LevelAPI Provisional
   * 
   * @anchor GadgetConnector
   */
  @Path("/wcmGadget/")
  public class GadgetConnector extends ExoDefaultSecurityTokenGenerator implements ResourceContainer {
  
    /** The Constant FCK_RESOURCE_BUNDLE_FILE. */
    public static final String         FCK_RESOURCE_BUNDLE_FILE      = "locale.services.fckeditor.FCKConnector";
  
    /** The application registry service. */
    private ApplicationRegistryService applicationRegistryService;
  
    /** The gadget registry service. */
    private GadgetRegistryService gadgetRegistryService;
  
    /** The Constant LAST_MODIFIED_PROPERTY. */
    private static final String LAST_MODIFIED_PROPERTY = "Last-Modified";
  
    /** The Constant IF_MODIFIED_SINCE_DATE_FORMAT. */
    private static final String IF_MODIFIED_SINCE_DATE_FORMAT = "EEE, dd MMM yyyy HH:mm:ss z";
  
    /** The log. */
    private static final Log LOG = ExoLogger.getLogger(GadgetConnector.class.getName());
  
    /**
     * Instantiates a new gadget connector.
     *
     * @param initParams the init params.
     */
    public GadgetConnector(InitParams initParams) throws Exception {
      applicationRegistryService = WCMCoreUtils.getService(ApplicationRegistryService.class);
      gadgetRegistryService = WCMCoreUtils.getService(GadgetRegistryService.class);
    }
  
   /**
    * Gets folders and files.
    *
    * @param currentFolder The current folder.
    * @param lang The language.
    * @param host The server address on which the gadget is deployed.
    * @return The folders and files.
    * @throws Exception The exception
    * 
    * @anchor GadgetConnector.getFoldersAndFiles
    */
   @GET
   @Path("/getFoldersAndFiles/")
   public Response getFoldersAndFiles(@QueryParam("currentFolder") String currentFolder,
                                      @QueryParam("lang") String lang,
                                      @QueryParam("host") String host) throws Exception {
     try {
       Response response = buildXMLResponse(currentFolder, lang, host);
       if (response != null)
         return response;
     } catch (Exception e) {
       if (LOG.isErrorEnabled()) {
         LOG.error("Error when perform getFoldersAndFiles: ", e);
       }
     }
     DateFormat dateFormat = new SimpleDateFormat(IF_MODIFIED_SINCE_DATE_FORMAT);
     return Response.ok().header(LAST_MODIFIED_PROPERTY, dateFormat.format(new Date())).build();
   }
 
   /**
    * Builds the XML response.
    *
    * @param currentFolder The current folder.
    * @param language The language.
    * @param host The server address on which the gadget is deployed.
    *
    * @return the response
    *
    * @throws Exception the exception
    */
   public Response buildXMLResponse(String currentFolder, String language, String host) throws Exception {
     List<ApplicationCategory> applicationCategories = getGadgetCategories();
     Element rootElement = createRootElement(currentFolder, applicationCategories, language, host);
     Document document = rootElement.getOwnerDocument();
     CacheControl cacheControl = new CacheControl();
     cacheControl.setNoCache(true);
     cacheControl.setNoStore(true);
     DateFormat dateFormat = new SimpleDateFormat(IF_MODIFIED_SINCE_DATE_FORMAT);
     return Response.ok(new DOMSource(document), MediaType.TEXT_XML)
                    .cacheControl(cacheControl)
                    .header(LAST_MODIFIED_PROPERTY, dateFormat.format(new Date()))
                    .build();
   }
 
   /**
    * Creates the root element.
    *
    * @param currentFolder The current folder.
    * @param applicationCategories The application categories.
    * @param language The language.
    *
    * @return The element
    *
    * @throws Exception the exception
    */
   private Element createRootElement(String currentFolder,
                                     List<ApplicationCategory> applicationCategories,
                                     String language,
                                     String host) throws Exception {
     Document document = null;
     DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
     DocumentBuilder builder = factory.newDocumentBuilder();
     document = builder.newDocument();
     if (applicationCategories.isEmpty()) {
       Locale locale = null;
       if (language == null) {
         locale = Locale.ENGLISH;
       } else {
         locale = new Locale(language);
       }
       ResourceBundle resourceBundle = ResourceBundle.getBundle(FCK_RESOURCE_BUNDLE_FILE, locale);
       String message = "";
       try {
         message = resourceBundle.getString("fckeditor.no-gadget");
       } catch (MissingResourceException e) {
         message = "fckeditor.no-gadget";
       }
       Element rootElement = document.createElement("Message");
       document.appendChild(rootElement);
       rootElement.setAttribute("number", "555");
       rootElement.setAttribute("text", message);
       rootElement.setAttribute("type", "Error");
       return rootElement;
     }
     Element rootElement = document.createElement("Connector");
     document.appendChild(rootElement);
     rootElement.setAttribute("resourceType", "Gadget");
     Element currentFolderElement = document.createElement("CurrentFolder");
     if (currentFolder == null || currentFolder.equals("/")){
       currentFolderElement.setAttribute("name", applicationCategories.get(0).getName());
       Element foldersElement = createFolderElement(document, applicationCategories);
       rootElement.appendChild(foldersElement);
     } else {
       PortalContainer container = PortalContainer.getInstance();
       RequestLifeCycle.begin(container);
       try {
         ApplicationCategory applicationCategory = applicationRegistryService
             .getApplicationCategory(currentFolder.substring(1, currentFolder.length() - 1));
         currentFolderElement.setAttribute("name", applicationCategory.getDisplayName());
         Element filesElement = createFileElement(document, applicationCategory, host);
         rootElement.appendChild(filesElement);
       } finally {
         RequestLifeCycle.end();
       }
     }
     rootElement.appendChild(currentFolderElement);
     return rootElement;
   }
 
   /**
    * Creates the folder element.
    *
    * @param document The document.
    * @param applicationCategories The application categories.
    *
    * @return The element
    *
    * @throws Exception the exception
    */
   private Element createFolderElement(Document document,
                                       List<ApplicationCategory> applicationCategories) throws Exception {
     Element folders = document.createElement("Folders");
     for (ApplicationCategory applicationCategory : applicationCategories) {
       Element folder = document.createElement("Folder");
       folder.setAttribute("name", applicationCategory.getDisplayName());
       folders.appendChild(folder);
     }
     return folders;
   }
 
   /**
    * Creates the file element.
    *
    * @param document The document.
    * @param applicationCategory The application category.
    *
    * @return the element
    *
    * @throws Exception the exception
    */
   private Element createFileElement(Document document,
                                     ApplicationCategory applicationCategory,
                                     String host) throws Exception {
     Element files = document.createElement("Files");
     List<Application> listApplication = applicationRegistryService.getApplications(applicationCategory,
                                                                                    ApplicationType.GADGET);
     for (Application application : listApplication) {
       Gadget gadget = gadgetRegistryService.getGadget(application.getApplicationName());
       Element file = document.createElement("File");
       file.setAttribute("name", gadget.getName());
       file.setAttribute("fileType", "nt_unstructured");
       file.setAttribute("size", "0");
       file.setAttribute("thumbnail", gadget.getThumbnail());
       file.setAttribute("description", gadget.getDescription());
 
       String fullurl = "";
       if (gadget.isLocal()) {
         fullurl = "/" + PortalContainer.getCurrentRestContextName() + "/" + gadget.getUrl();
       } else {
         fullurl = gadget.getUrl();
       }
       file.setAttribute("url", fullurl);
 
       String data = "{\"context\":{\"country\":\"US\",\"language\":\"en\"},\"gadgets\":[{\"moduleId\":0,\"url\":\""
           + fullurl + "\",\"prefs\":[]}]}";
       URL url = new URL(host + "/eXoGadgetServer/gadgets/metadata");
       URLConnection conn = url.openConnection();
       conn.setDoOutput(true);
       OutputStreamWriter wr = new OutputStreamWriter(conn.getOutputStream());
       wr.write(data);
       wr.flush();
       String strMetadata = IOUtils.toString(conn.getInputStream(), "UTF-8");
       wr.close();
       JSONObject metadata = new JSONObject(strMetadata.toString());
 
       ConversationState conversationState = ConversationState.getCurrent();
       String userId = conversationState.getIdentity().getUserId();
       String token = createToken(gadget.getUrl(), userId, userId, new Random().nextLong(), "default");
       JSONObject obj = metadata.getJSONArray("gadgets").getJSONObject(0);
       obj.put("secureToken", token);
 
       file.setAttribute("metadata", metadata.toString());
       files.appendChild(file);
     }
     return files;
   }
 
   /**
    * Gets the gadget categories.
    *
    * @return The gadget categories.
    *
    * @throws Exception the exception
    */
   private List<ApplicationCategory> getGadgetCategories() throws Exception {
     List<ApplicationCategory> gadgetCategories = new ArrayList<ApplicationCategory>();
     PortalContainer container = PortalContainer.getInstance();
     RequestLifeCycle.begin(container);
     try {
       List<ApplicationCategory> applicationCategories = applicationRegistryService.getApplicationCategories();
       for (ApplicationCategory applicationCategory : applicationCategories) {
         if (!applicationRegistryService.getApplications(applicationCategory, ApplicationType.GADGET)
                                        .isEmpty()) {
           gadgetCategories.add(applicationCategory);
         }
       }
     } finally {
       RequestLifeCycle.end();
     }
     return gadgetCategories;
   }
 }