/**
    * Copyright (C) 2005-2009 Alfresco Software Limited.
    *
    * This file is part of the Spring Surf Extension project.
    *
    * 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 org.springframework.extensions.webscripts;
  
  import javax.servlet.http.HttpServletResponse;
  
  import org.apache.commons.logging.Log;
  import org.apache.commons.logging.LogFactory;
  import org.springframework.extensions.webscripts.Description.FormatStyle;
  
  
  /**
   * Basic Implementation of a Web Script Request
   * 
   * @author davidc
   */
  public abstract class WebScriptRequestImpl implements WebScriptRequest
  {
      protected static final Log logger = LogFactory.getLog(WebScriptRequestImpl.class);
      private Runtime runtime;
  
      // parsed request content
      private Object requestContent = this;
  
  
      /**
       * Construct
       * 
       * @param runtime
       */
      public WebScriptRequestImpl(Runtime runtime)
      {
          this.runtime = runtime;
      }
      
      /* (non-Javadoc)
       * @see org.alfresco.web.scripts.WebScriptRequest#getRuntime()
       */
      public Runtime getRuntime()
      {
          return runtime;
      }
      
      /* (non-Javadoc)
       * @see org.alfresco.web.scripts.WebScriptRequest#getExtensionPath()
       */
      public String getExtensionPath()
      {
          String extensionPath = "";
          Match match = getServiceMatch();
          if (match != null)
          {
              String matchPath = getServiceMatch().getPath();
              String pathInfo = getPathInfo();
              if (pathInfo != null)
              {
                  extensionPath = pathInfo.substring(matchPath.length());
              }
          }
          return extensionPath;
      }
  
      /* (non-Javadoc)
       * @see org.alfresco.web.scripts.WebScriptRequest#isGuest()
       */
      public boolean isGuest()
      {
          return Boolean.valueOf(getParameter("guest"));
      }
  
      /* (non-Javadoc)
       * @see org.alfresco.web.scripts.WebScriptRequest#getFormat()
       */
      public String getFormat()
      {
          String format = null;
          Match match = getServiceMatch();
          if (match != null)
          {
              Description desc = match.getWebScript().getDescription();
              FormatStyle style = desc.getFormatStyle();
              
              // extract format from extension
             if (style == FormatStyle.extension || style == FormatStyle.any)
             {
                 String pathInfo = getPathInfo();
                 if (pathInfo != null)
                 {
                     int extIdx = pathInfo.lastIndexOf('.');
                     if (extIdx != -1)
                     {
                         // format extension is only valid as the last URL element 
                         int pathIdx = pathInfo.lastIndexOf('/');
                         if (pathIdx < extIdx)
                         {
                             format = pathInfo.substring(extIdx +1);
                         }
                     }
                 }
             }
             
             // extract format from argument
             if (style == FormatStyle.argument || style == FormatStyle.any)
             {
                 String argFormat = getParameter("format");
                 if (argFormat != null)
                 {
                     if (format != null && format.length() > 0)
                     {
                         throw new WebScriptException("Format specified both in extension and format argument");
                     }
                     format = argFormat;
                 }
             }
             
             // negotiate format, if necessary
             if (format == null || format.length() == 0)
             {
                 String accept = getHeader("Accept");
                 NegotiatedFormat[] negotiatedFormats = desc.getNegotiatedFormats();
                 if (accept != null && negotiatedFormats != null)
                 {
                     if (logger.isDebugEnabled())
                         logger.debug("Negotiating format for " + accept);
                         
                     format = NegotiatedFormat.negotiateFormat(accept, negotiatedFormats);
                     if (format == null)
                     {
                         throw new WebScriptException(HttpServletResponse.SC_NOT_ACCEPTABLE, "Cannot negotiate appropriate response format for Accept: " + accept);
                     }
                 }
             }
             
             // fallback to default
             if (format == null || format.length() == 0)
             {
                 format = desc.getDefaultFormat();
             }
         }
         
         return (format == null || format.length() == 0) ? "" : format;
     }
 
     /* (non-Javadoc)
      * @see org.alfresco.web.scripts.WebScriptRequest#getFormatStyle()
      */
     public FormatStyle getFormatStyle()
     {
         Match match = getServiceMatch();
         if (match == null)
         {
             return FormatStyle.any;
         }
         FormatStyle style = match.getWebScript().getDescription().getFormatStyle();
         if (style != FormatStyle.any)
         {
             return style;
         }
         else
         {
             String argFormat = getParameter("format");
             if (argFormat != null && argFormat.length() > 0)
             {
                 return FormatStyle.argument;
             }
             else
             {
                 return FormatStyle.extension;
             }
         }
     }
 
     /* (non-Javadoc)
      * @see org.alfresco.web.scripts.WebScriptRequest#getJSONCallback()
      */
     public String getJSONCallback()
     {
         return getParameter("alf_callback");
     }
 
     /* (non-Javadoc)
      * @see org.alfresco.web.scripts.WebScriptRequest#forceSuccessStatus()
      */
     public boolean forceSuccessStatus()
     {
         return false;
     }
     
     /* (non-Javadoc)
      * @see org.alfresco.web.scripts.WebScriptRequest#getContentType()
      */
     public String getContentType()
     {
         String contentType = getHeader("Content-Type");
         if (contentType != null && contentType.startsWith("multipart/form-data"))
         {
             contentType = "multipart/form-data";
         }
         return contentType;
     }
     
     /* (non-Javadoc)
      * @see org.alfresco.web.scripts.WebScriptRequest#parseContent()
      */
     public Object parseContent()
     {
         if (requestContent == this)
         {
             requestContent = null;
             String contentType = getContentType();
             if (contentType != null && contentType.length() > 0)
             {
                 FormatRegistry formatRegistry = getRuntime().getContainer().getFormatRegistry();
                 FormatReader<Object> reader = formatRegistry.getReader(contentType);
                 if (reader != null)
                 {
                     if (logger.isDebugEnabled())
                         logger.debug("Converting request (mimetype: " + contentType + ") to " + reader.getDestinationClass().getName());
                     
                     requestContent = reader.read(this);
                 }
             }
         }
         return requestContent;
     }
     
 }