////////////////////////////////////////////////////////////////////////////////
   // 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;
  
  import org.millscript.commons.alert.alerts.ClassCastAlert;
  import org.millscript.commons.alert.alerts.ClassNotFoundAlert;
  import org.millscript.commons.alert.alerts.Fault;
  import org.millscript.commons.alert.alerts.IllegalAccessAlert;
  import org.millscript.commons.alert.alerts.InstantiationAlert;
  import org.millscript.commons.vfs.mime.MIMETypeHandler;
  
  import java.net.URI;
  import java.net.URISyntaxException;
  
  import javax.activation.CommandInfo;
  import javax.activation.CommandMap;
  import javax.activation.FileTypeMap;
  
  /**
   * This class provides the skeletal implementation of a virtual filesystem
   * entry,
   */
  public abstract class AbstractVEntry< V extends VVolume > implements VEntry {
  
      /**
       * The command map for determining the handler for a given MIME type.
       */
      private static final CommandMap COMMANDS = CommandMap.getDefaultCommandMap();
  
      /**
       * The file type map for determining the MIME type of a file, based on file
       * extension.
       */
      private static final FileTypeMap MIME_TYPES = FileTypeMap.getDefaultFileTypeMap();
  
      /**
       * The entries name.
       */
      private final String entryName;
  
      /**
       * The entries parent folder.
       */
      private final VFolder parentFolder;
  
      /**
       * The volume this entry is held on.
       */
      private final V volume;
  
      /**
       * Constructs a new virtual filesystem entry with the specified name,
       * parent folder and volume.
       *
       * @param vol   the volume this entry is held on
       * @param parent    the parent folder for this entry
       * @param name  the name of the entry
       */
      protected AbstractVEntry( final V vol, final VFolder parent, final String name ) {
          this.volume = vol;
          this.parentFolder = parent;
          this.entryName = name;
      }
  
      /**
       * @see org.millscript.commons.vfs.VEntry#appendAbsolutePath(java.lang.StringBuffer)
       */
      public final StringBuffer appendAbsolutePath( final StringBuffer buffer ) {
          return this.appendRelativePath( buffer.append( '/' ) );
      }
  
      /**
       * @see org.millscript.commons.vfs.VEntry#appendAbsolutePathOnVolume(java.lang.StringBuffer)
       */
      public final StringBuffer appendAbsolutePathOnVolume( final StringBuffer buffer ) {
          return this.appendRelativePathOnVolume( buffer.append( '/' ) );
      }
  
      /**
       * @see org.millscript.commons.vfs.VEntry#getAbsolutePath()
       */
     public final String getAbsolutePath() {
         return this.appendAbsolutePath( new StringBuffer() ).toString();
     }
 
     /**
      * @see org.millscript.commons.vfs.VEntry#getAbsolutePathOnVolume()
      */
     public final String getAbsolutePathOnVolume() {
         return this.appendAbsolutePathOnVolume( new StringBuffer() ).toString();
     }
 
     /**
      * @see org.millscript.commons.vfs.VEntry#getMIMEType(java.lang.String)
      */
     public final String getMIMEType( final String fileName ) {
         return MIME_TYPES.getContentType( fileName );
     }
 
     /**
      * @see org.millscript.commons.vfs.VEntry#getMIMETypeHandler(java.lang.String)
      */
     public final MIMETypeHandler getMIMETypeHandler( final String type ) {
         // Do we have a command to handle this type
         final CommandInfo command = COMMANDS.getCommand( type, "vfs-mime-handler" );
         if ( command == null ) {
             // We don't have a command for this type
             return null;
         }
         // Yes we do have a command for this type
         // Try to make a new instance of the command
         try {
             final Class c = Class.forName( command.getCommandClass() );
             return (MIMETypeHandler) c.newInstance();
         } catch ( ClassCastException ex ) {
             throw new ClassCastAlert().setParentThrowable( ex ).mishap();
         } catch ( ClassNotFoundException ex ) {
             throw new ClassNotFoundAlert().culpritClass( command.getCommandClass() ).setParentThrowable( ex ).mishap();
         } catch ( InstantiationException ex ) {
             throw new InstantiationAlert().culpritClass( command.getCommandClass() ).setParentThrowable( ex ).mishap();
         } catch ( IllegalAccessException ex ) {
             throw new IllegalAccessAlert().culpritClass( command.getCommandClass() ).setParentThrowable( ex ).mishap();
         }
     }
 
     /**
      * @see org.millscript.commons.vfs.VEntry#getName()
      */
     public final String getName() {
         return this.entryName;
     }
 
     /**
      * @see org.millscript.commons.vfs.VEntry#getRelativePath()
      */
     public final String getRelativePath() {
         return this.appendRelativePath( new StringBuffer() ).toString();
     }
 
     /**
      * @see org.millscript.commons.vfs.VEntry#getRelativePathOnVolume()
      */
     public final String getRelativePathOnVolume() {
         return this.appendRelativePathOnVolume( new StringBuffer() ).toString();
     }
 
     /**
      * @see org.millscript.commons.vfs.VEntry#getParent()
      */
     public final VFolder getParent() {
         return this.parentFolder;
     }
 
     /**
      * @see org.millscript.commons.vfs.VEntry#getURI()
      */
     public final URI getURI() {
         try {
             return new URI( this.appendURI( new StringBuffer() ).toString() );
         } catch ( URISyntaxException ex ) {
             throw new Fault(
                 "Could not make a valid URI from this virtual filesystem entry"
             ).culprit( "ventry", this ).mishap();
         }
     }
 
     /**
      * @see org.millscript.commons.vfs.VEntry#getVolume()
      */
     public final V getVolume() {
         return this.volume;
     }
 
 }