////////////////////////////////////////////////////////////////////////////////
   // MillScript: an Open Spice interpreter and batch website creation tool
   // Copyright (C) 2005 Kevin Rogers
   //
   // This file is part of MillScript.
   //
   // MillScript is free software; you can redistribute it and/or modify it under
   // the terms of the GNU General Public License as published by the Free
   // Software Foundation; either version 2 of the License, or (at your option)
  // any later version.
  //
  // MillScript 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
  // MillScript; if not, write to the Free Software Foundation, Inc., 59 Temple
  // Place, Suite 330, Boston, MA  02111-1307  USA
  ////////////////////////////////////////////////////////////////////////////////
  package org.millscript.commons.vfs.protocols.http;
  
  import org.millscript.commons.alert.Alert;
  import org.millscript.commons.vfs.AbstractVFile;
  import org.millscript.commons.vfs.VFolder;
  import org.millscript.commons.vfs.alerts.VCannotOpenEntryAlert;
  import org.millscript.commons.vfs.alerts.VEntryNotFoundAlert;
  
  import gnu.inet.http.ByteArrayResponseBodyReader;
  import gnu.inet.http.Request;
  import gnu.inet.http.Response;
  
  import java.io.ByteArrayInputStream;
  import java.io.InputStream;
  import java.io.OutputStream;
  
  /**
   * This class implements a virtual filesystem file for an HTTP filesystem file.
   */
  public class HttpFile extends AbstractVFile< HttpVolume > {
  
      /**
       * Constructs a new HTTP virtual filesystem file with the specified name,
       * parent folder and volume.
       *
       * @param vol   the volume this entry is held on
       * @param parent    the parent folder for this file
       * @param name  the name of the file
       */
      HttpFile( final HttpVolume vol, final VFolder parent, final String name ) {
          super( vol, parent, name );
      }
  
      /**
       * Constructs a new HTTP virtual filesystem file with the specified name,
       * parent folder. This file will belong to the same volume as the specified
       * parent folder.
       *
       * @param parent    the parent folder for this file
       * @param name  the name of the file
       */
      HttpFile( final HttpFolder parent, final String name ) {
          super( parent.getVolume(), parent, name );
      }
  
      /**
       * @see org.millscript.commons.vfs.VEntry#exists()
       */
      public boolean exists() {
          final HttpVolume vol = this.getVolume();
          // Try to get the segment as a folder
          Request request = vol.httpConnection.newRequest(
              "HEAD",
              this.getAbsolutePath()
          );
          // Execute the method and capture the resulting status code
          Response response = vol.dispatch( request );
          if ( response.getCode() == 200 ) {
              // Success
              return true;
          } else {
              return false;
          }
      }
  
      /**
       * @see org.millscript.commons.vfs.VFile#getAppendOutputStream()
       */
      public OutputStream getAppendOutputStream() {
          // TODO Auto-generated method stub
          return null;
      }
  
      /**
       * @see org.millscript.commons.vfs.VFile#getContentMIMEType()
       */
      @Override
      public String getContentMIMEType() {
          // TODO - This method can report much better errors based on the HTTP
         // status code, so do it...
         final HttpVolume vol = this.getVolume();
         // Try to get the segment as a folder
         Request request = vol.httpConnection.newRequest(
             "HEAD",
             this.getAbsolutePath()
         );
         // Execute the method and capture the resulting status code
         Response response = vol.dispatch( request );
         if ( response.getCode() == 200 ) {
             // Success
             final String header = response.getHeader( "Content-Type" );
             // Do we have the content-type header?
             if ( header != null ) {
                 final int n = header.indexOf( ';' );
                 if ( n < 0 ) {
                     return header;
                 } else {
                     return header.substring( 0, n );
                 }
             }
             // There wasn't a content type header in the HTTP response, so fall
             // through to the default normal calculation
         } else {
             // MISHAP: We didn't find the file on the server
             throw VEntryNotFoundAlert.entryDoesNotExist( this.getName() ).mishap();
         }
         // We haven't managed to get a proper MIME type from the HTTP server,
         // so use our normal calculation based on the filename
         return super.getContentMIMEType();
     }
 
     /**
      * @see org.millscript.commons.vfs.VFile#getInputStream()
      */
     public InputStream getInputStream() {
         final HttpVolume vol = this.getVolume();
         // Try to get the segment as a folder
         Request request = vol.httpConnection.newRequest(
             "GET",
             this.getAbsolutePath()
         );
         // Make a body reader to hold the body of the request
         final ByteArrayResponseBodyReader reader = new ByteArrayResponseBodyReader();
         request.setResponseBodyReader( reader );
         // Execute the method and capture the resulting status code
         Response response = vol.dispatch( request );
         if ( response.getCode() == 200 ) {
             // Success
             return new ByteArrayInputStream( reader.toByteArray() );
         } else {
             // OK, into error handling mode
             throw(
                 this.handleResponse( response ).remishap()
             );
         }
     }
 
     /**
      * @see org.millscript.commons.vfs.VFile#getOutputStream()
      */
     public OutputStream getOutputStream() {
         // TODO Auto-generated method stub
         return null;
     }
 
     private Alert handleResponse( final Response response ) {
         // The entry doesn't exist at all.
         return VCannotOpenEntryAlert.fileNotFound( this ).culprit(
             "http response",
             response.getMessage()
         ).mishap();
     }
 
 }