////////////////////////////////////////////////////////////////////////////////
   // 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.Alert;
  import org.millscript.commons.alert.AlertDecorator;
  import org.millscript.commons.vfs.alerts.VFSAlert;
  import org.millscript.commons.vfs.protocols.file.LocalFolder;
  import org.millscript.commons.vfs.util.ChrootVolume;
  import org.millscript.commons.vfs.util.Resolver;
  import org.millscript.commons.vfs.util.SimpleVolume;
  
  /**
   * This class provides the skeletal implementation of a virtual filesystem
   * folder,
   */
  public abstract class AbstractVFolder< V extends VVolume > extends AbstractVEntry< V > implements AlertDecorator, VFolder {
  
      /**
       * Constructs a new virtual filesystem folder with the specified name,
       * parent folder and volume.
       *
       * @param vol   the volume this entry is held on
       * @param parent    the parent folder for this folder
       * @param name  the name of the folder
       */
      public AbstractVFolder( final V vol, final VFolder parent, final String name ) {
          super( vol, parent, name );
      }
  
      /**
       * @see org.millscript.commons.vfs.VEntry#appendRelativePath(java.lang.StringBuffer)
       */
      public final StringBuffer appendRelativePath( final StringBuffer buff ) {
          // If we have a parent, append it's relative path to the buffer.
          if ( this.getParent() == null ) {
              // This is the root, so we append any base path for this volume.
              return buff;
          } else {
              // This will recurse all the way up the chain to give us the
              // relative path from the root of the filesystem.
              // Append the parent entry to the buffer
              this.getParent().appendRelativePath( buff );
              // Append this entry to the buffer followed by a slash
              return buff.append( this.getName() ).append( '/' );
          }
      }
  
      /**
       * @see org.millscript.commons.vfs.VEntry#appendRelativePathOnVolume(java.lang.StringBuffer)
       */
      public final StringBuffer appendRelativePathOnVolume( final StringBuffer buff ) {
          // If we have a parent and it's volume is the same as ours, append it's
          // relative path to the buffer.
          // This will recurse all the way up the chain to the root of the volume
          // this file belongs on, to give us the relative path from the root of
          // the volume.
          // TODO - This should probably use equality not identity but we need
          // implementations of hashCode() and equals()
          if ( this.getParent() == null ) {
              // Ah. No parent, so we must be at the top of the hierarchy
              return buff;
          } else if ( this.getParent().getVolume() == this.getVolume() ) {
              // The parent volume is the same as this one, so we should append
              // the parents path as it's on the same volume
              // Append the parent entry to the buffer
              this.getParent().appendRelativePathOnVolume( buff );
              // Append this entry to the buffer followed by a slash
              return buff.append( this.getName() ).append( '/' );
          } else {
              // This is the root, so we append any base path for this volume.
              return buff;
          }
      }
  
      /**
       * @see org.millscript.commons.vfs.VEntry#appendURI(java.lang.StringBuffer)
       */
      public final StringBuffer appendURI( final StringBuffer buffer ) {
          // If we have a parent, append it's URI to the buffer.
          // This will recurse all the way up the chain to give us the complete
         // URI for this entry
         if ( this.getParent() == null ) {
             // No parent - this is the root entry
             this.getVolume().appendBaseURI( buffer );
         } else {
             // We have a parent, so append it's URI
             this.getParent().appendURI( buffer );
             buffer.append( this.getName() );
         }
         return buffer.append( '/' );
     }
 
     /**
      * @see org.millscript.commons.vfs.VFolder#chroot()
      */
     public final VVolume chroot() {
         return new ChrootVolume( this );
     }
 
     /**
      * @see org.millscript.commons.alert.AlertDecorator#decorate(org.millscript.commons.alert.Alert)
      */
     public Alert decorate( final Alert alert ) {
         return alert.culprit( "vfolder", this );
     }
 
     /**
      * @see org.millscript.commons.vfs.VFolder#make(java.lang.String)
      */
     public final VFolder make( final String segment ) {
         // First get the virtual folder for the new segment
         final VFolder child = this.getVFolder( segment );
         // Make it...
         return child.make();
     }
 
     /**
      * @see org.millscript.commons.vfs.VFolder#resolveAsFile(java.lang.String)
      */
     public final VFile resolveAsFile( final String path ) {
         return Resolver.resolveAsFile( this, path );
     }
 
     /**
      * @see org.millscript.commons.vfs.VFolder#resolveAsFolder(java.lang.String)
      */
     public final VFolder resolveAsFolder( final String path ) {
         return Resolver.resolveAsFolder( this, path );
     }
 
     /**
      * @see org.millscript.commons.vfs.VFolder#resolveAsVolume(java.lang.String)
      */
     public final VVolume resolveAsVolume( final String path ) {
         return Resolver.resolveAsVolume( this, path );
     }
 
     /**
      * @see org.millscript.commons.vfs.VFolder#toLocal()
      */
     public LocalFolder toLocal() {
         // TODO - Must implement and add hook to remove temporary files
         throw new VFSAlert(
             "Can't make a local copy of a virtual folder yet"
         ).decorate( this ).mishap();
     }
 
     /**
      * @see java.lang.Object#toString()
      */
     @Override
     public String toString() {
         final StringBuffer buff = new StringBuffer( "VFOLDER( " );
         this.appendAbsolutePath( buff );
         buff.append( " )" );
         return buff.toString();
     }
 
     /**
      * @see org.millscript.commons.vfs.VFolder#toVolume()
      */
     public final VVolume toVolume() {
         return new SimpleVolume( this );
     }
 
 }