////////////////////////////////////////////////////////////////////////////////
   // 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.ftp;
  
  import org.millscript.commons.alert.alerts.IOAlert;
  import org.millscript.commons.vfs.AbstractVFile;
  import org.millscript.commons.vfs.VFolder;
  import org.millscript.commons.vfs.alerts.VCannotOpenEntryAlert;
  
  import gnu.inet.ftp.FTPException;
  
  import java.io.IOException;
  import java.io.InputStream;
  import java.io.OutputStream;
  
  /**
   * This class implements a virtual filesystem file for an FTP filesystem file.
   */
  public class FtpFile extends AbstractVFile< FtpVolume > {
  
      /**
       * Constructs a new FTP 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
       */
      FtpFile( final FtpVolume vol, final VFolder parent, final String name ) {
          super( vol, parent, name );
      }
  
      /**
       * Constructs a new FTP 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
       */
      FtpFile( final FtpFolder parent, final String name ) {
          super( parent.getVolume(), parent, name );
      }
  
      /**
       * @see org.millscript.commons.vfs.VEntry#exists()
       */
      public boolean exists() {
          final StringBuffer uri = this.appendAbsolutePath( new StringBuffer() );
          final FtpVolume vol = this.getVolume();
          try {
              // Treat the entry as a folder and try to change into it
              if ( vol.ftpConnection.changeWorkingDirectory( uri.toString() ) ) {
                  // Ooo, we succeeded, so this entry is a folder
                  return false;
              } else {
                  // Ok, the segment isn't a folder so let's try and find out if
                  // it exists. We can't use STAT, so lets try LIST.
                  // TODO - Check this does throw an FTPException if the path
                  // doesn't exist
                  final InputStream listStream = vol.ftpConnection.list( uri.toString() );
                  listStream.close();
                  // We're still here, so this entry must exist and be a file
                  return true;
              }
          } catch ( IOException ex ) {
              // Alert - an i/o problem
              throw new IOAlert(
                  "Cannot dispatch the FTP request"
              ).culprit( "message", ex.getMessage() ).setParentThrowable( ex ).mishap();
          }
      }
  
      /**
       * @see org.millscript.commons.vfs.VFile#getAppendOutputStream()
       */
      public OutputStream getAppendOutputStream() {
          final StringBuffer uri = this.appendAbsolutePath( new StringBuffer() );
          try {
              return this.getVolume().ftpConnection.append( uri.toString() );
          } catch ( FTPException ex ) {
             // TODO - This should be a little bit better
             throw VCannotOpenEntryAlert.entryIsNotAFile( this ).setParentThrowable( ex ).mishap();
         } catch ( IOException ex ) {
             // Alert - an i/o problem
             throw new IOAlert(
                 "Cannot dispatch the FTP request"
             ).culprit( "message", ex.getMessage() ).setParentThrowable( ex ).mishap();
         }
     }
 
     /**
      * @see org.millscript.commons.vfs.VFile#getInputStream()
      */
     public InputStream getInputStream() {
         final StringBuffer uri = this.appendAbsolutePath( new StringBuffer() );
         try {
             return this.getVolume().ftpConnection.retrieve( uri.toString() );
         } catch ( FTPException ex ) {
             // TODO - This should be a little bit better
             throw VCannotOpenEntryAlert.fileNotFound( this ).setParentThrowable( ex ).mishap();
         } catch ( IOException ex ) {
             // Alert - an i/o problem
             throw new IOAlert(
                 "Cannot dispatch the FTP request"
             ).culprit( "message", ex.getMessage() ).setParentThrowable( ex ).mishap();
         }
     }
 
     /**
      * @see org.millscript.commons.vfs.VFile#getOutputStream()
      */
     public OutputStream getOutputStream() {
         final StringBuffer uri = this.appendAbsolutePath( new StringBuffer() );
         try {
             return this.getVolume().ftpConnection.store( uri.toString() );
         } catch ( FTPException ex ) {
             // TODO - This should be a little bit better
             throw VCannotOpenEntryAlert.entryIsNotAFile( this ).setParentThrowable( ex ).mishap();
         } catch ( IOException ex ) {
             // Alert - an i/o problem
             throw new IOAlert(
                 "Cannot dispatch the FTP request"
             ).culprit( "message", ex.getMessage() ).setParentThrowable( ex ).mishap();
         }
     }
 
 }