/*
    * Copyright 2013 smartics, Kronseder & Reiner GmbH
    *
    * 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 de.smartics.properties.admin.resources.share;
  
  import java.io.IOException;
  import java.io.OutputStream;
  import java.io.PrintStream;
  import java.net.URI;
  
  import javax.inject.Inject;
  import javax.ws.rs.ForbiddenException;
  import javax.ws.rs.core.MediaType;
  import javax.ws.rs.core.Response;
  import javax.ws.rs.core.UriBuilder;
  import javax.ws.rs.ext.Provider;
  
  import de.smartics.html5.jatl.HtmlFactory;
  import de.smartics.html5.jatl.HtmlResourceContext;
  import de.smartics.properties.admin.resources.representation.html.share.ExceptionHtmlRepresentationRenderer;
  import de.smartics.resteasy.hypermedia.renderer.AbstractExceptionHandler;
  import de.smartics.resteasy.hypermedia.renderer.I18nProvider;
  import de.smartics.resteasy.hypermedia.renderer.RepresentationRenderer;
  import de.smartics.resteasy.hypermedia.renderer.ResourceContext;
  
  /**
   * Handles raised exceptions by transforming them to their representations for
   * the client.
   */
  @Provider
  public class ExceptionHandler extends AbstractExceptionHandler
  {
    // ********************************* Fields *********************************
  
    // --- constants ------------------------------------------------------------
  
    // --- members --------------------------------------------------------------
  
    /**
     * The factory to create the HTML documents.
     */
    @Inject
    protected HtmlFactory factory;
  
    /**
     * Provides access to internationalization information.
     */
    @Inject
    protected I18nProvider i18nProvider;
  
    // ****************************** Initializer *******************************
  
    // ****************************** Constructors ******************************
  
    // ****************************** Inner Classes *****************************
  
    // ********************************* Methods ********************************
  
    // --- init -----------------------------------------------------------------
  
    // --- get&set --------------------------------------------------------------
  
    // --- business -------------------------------------------------------------
  
    @Override
    protected I18nProvider getI18nProvider()
    {
      return i18nProvider;
    }
  
    @Override
    public Response toResponse(final Throwable exception)
    {
      if (exception instanceof ForbiddenException)
      {
        final String redirect =
            request.getUri().getAbsolutePath().toASCIIString();
        final UriBuilder builder =
            uriInfo.getBaseUriBuilder().segment("..")
                .queryParam("redirect-to", redirect);
        final URI login = builder.build();
        return Response.seeOther(login).build();
      }
      else
      {
        try
        {
         writeContents(exception);
 
         return Response.status(Response.Status.INTERNAL_SERVER_ERROR).build();
       }
       catch (final IOException e)
       {
         throw new IllegalStateException("Cannot write exception to response: "
                                         + e.getMessage(), exception);
       }
     }
   }
 
   private void writeContents(final Throwable exception) throws IOException
   {
     final OutputStream entityStream = response.getOutputStream();
 
     final ResourceContext context = createContext();
 
     for (final MediaType contentType : request.getHttpHeaders()
         .getAcceptableMediaTypes())
     {
       if (MediaType.TEXT_HTML_TYPE.isCompatible(contentType))
       {
         final HtmlResourceContext htmlContext =
             new HtmlResourceContext(context, factory);
         final RepresentationRenderer<Throwable> view =
             new ExceptionHtmlRepresentationRenderer(htmlContext, exception,
                 entityStream);
         view.render();
         return;
       }
     }
 
     final PrintStream print = new PrintStream(entityStream);
     print.append(exception.toString());
   }
 
   // --- object basics --------------------------------------------------------
 }