/*
    * Licensed to the Apache Software Foundation (ASF) under one
    * or more contributor license agreements.  See the NOTICE file
    * distributed with this work for additional information
    * regarding copyright ownership.  The ASF licenses this file
    * to you 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 org.apache.myfaces.shared.renderkit;
  
  import javax.faces.context.FacesContext;
  
  import org.apache.myfaces.shared.renderkit.html.HtmlRendererUtils;
  import org.apache.myfaces.shared.util.StringUtils;
  
  public class ContentTypeUtils
  {
      public static final String HTML_CONTENT_TYPE = "text/html";
      public static final String TEXT_ANY_CONTENT_TYPE = "text/*";
      public static final String ANY_CONTENT_TYPE = "*/*";
  
      public static final String[] HTML_ALLOWED_CONTENT_TYPES = {HTML_CONTENT_TYPE, 
          ANY_CONTENT_TYPE, TEXT_ANY_CONTENT_TYPE};
      
      public static final String XHTML_CONTENT_TYPE = "application/xhtml+xml";
      public static final String APPLICATION_XML_CONTENT_TYPE = "application/xml";
      public static final String TEXT_XML_CONTENT_TYPE = "text/xml";
      
      public static final String[] XHTML_ALLOWED_CONTENT_TYPES = {XHTML_CONTENT_TYPE, 
          APPLICATION_XML_CONTENT_TYPE, TEXT_XML_CONTENT_TYPE};
      
      public static final String[] AJAX_XHTML_ALLOWED_CONTENT_TYPES = {XHTML_CONTENT_TYPE};
  
  
      /**
       * Indicate if the passes content type match one of the options passed. 
       */
      public static boolean containsContentType(String contentType, String[] allowedContentTypes)
      {
          if (allowedContentTypes == null)
          {
              return false;
          }
          for (int i = 0; i < allowedContentTypes.length; i++)
          {
              if (allowedContentTypes[i].indexOf(contentType) != -1)
              {
                  return true;
              }
          }
          return false;
      }
  
      public static String chooseWriterContentType(String contentTypeListString, 
              String[] htmlContentTypes, String[] xhtmlContentTypes)
      {
          String[] contentTypeList = splitContentTypeListString(contentTypeListString);
          String[] supportedContentTypeArray = HtmlRendererUtils.getSupportedContentTypes();
          String selectedContentType = null;
          for (int i = 0; i < supportedContentTypeArray.length; i++)
          {
              String supportedContentType = supportedContentTypeArray[i].trim();
  
              for (int j = 0; j < contentTypeList.length; j++)
              {
                  String contentType = (String) contentTypeList[j];
  
                  if (contentType.indexOf(supportedContentType) != -1)
                  {
                      if (containsContentType(contentType, htmlContentTypes))
                      {
                          selectedContentType = HTML_CONTENT_TYPE;
                      }
                      else if (containsContentType(contentType, xhtmlContentTypes))
                      {
                          selectedContentType = XHTML_CONTENT_TYPE;
                      }
                      break;
                  }
              }
              if (selectedContentType != null)
              {
                  break;
              }
          }
          return selectedContentType;
      }
      
      public static String[] splitContentTypeListString(String contentTypeListString)
     {
         String[] splittedArray = StringUtils.splitShortString(contentTypeListString, ',');
         for (int i = 0; i < splittedArray.length; i++)
         {
             int semicolonIndex = splittedArray[i].indexOf(';');
             if (semicolonIndex != -1)
             {
                 splittedArray[i] = splittedArray[i].substring(0,semicolonIndex);
             }
         }
         return splittedArray;
     }
     
     public static String getContentTypeFromAcceptHeader(FacesContext context)
     {
         String contentTypeListString = (String) context.getExternalContext()
             .getRequestHeaderMap().get("Accept");
         // There is a windows mobile IE client (6.12) sending
         // "application/vnd.wap.mms-message;*/*"
         // Note that the Accept header should be written as 
         // "application/vnd.wap.mms-message,*/*" ,
         // so this is bug of the client. Anyway, this is a workaround ...
         if (contentTypeListString != null
                 && contentTypeListString
                         .startsWith("application/vnd.wap.mms-message;*/*"))
         {
             contentTypeListString = "*/*";
         }
         return contentTypeListString;
     }
 
 }