/*
    * Copyright (c) 2002-2022, City of Paris
    * All rights reserved.
    *
    * Redistribution and use in source and binary forms, with or without
    * modification, are permitted provided that the following conditions
    * are met:
    *
    *  1. Redistributions of source code must retain the above copyright notice
   *     and the following disclaimer.
   *
   *  2. Redistributions in binary form must reproduce the above copyright notice
   *     and the following disclaimer in the documentation and/or other materials
   *     provided with the distribution.
   *
   *  3. Neither the name of 'Mairie de Paris' nor 'Lutece' nor the names of its
   *     contributors may be used to endorse or promote products derived from
   *     this software without specific prior written permission.
   *
   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
   * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDERS OR CONTRIBUTORS BE
   * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
   * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
   * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
   * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
   * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
   * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
   * POSSIBILITY OF SUCH DAMAGE.
   *
   * License 1.0
   */
  package fr.paris.lutece.util.filesystem;
  
  import fr.paris.lutece.portal.service.util.AppLogService;
  import fr.paris.lutece.portal.service.util.AppPathService;
  
  // Java IO
  import java.io.File;
  import java.io.IOException;
  
  // Java Util
  import java.util.ArrayList;
  import java.util.List;
  import java.util.TreeSet;
  
  import javax.activation.MimetypesFileTypeMap;
  
  import org.apache.commons.lang3.ArrayUtils;
  
  /**
   * This Service is used to manipulate Files and Directories in the File System.
   */
  public final class FileSystemUtil
  {
      private static final String DEFAULT_MIME_TYPE = "application/octet-stream";
      private static final String FILE_SEPARATOR = File.separator;
      private static final String FILE_MIME_TYPE = "WEB-INF" + FILE_SEPARATOR + "conf" + FILE_SEPARATOR + "mime.types";
  
      /**
       * Private constructor
       */
      private FileSystemUtil( )
      {
      }
  
      /**
       * Returns the sub-directories of a directory.
       *
       * @param strRoot
       *            the root directory.
       * @param strDirectoryRelativePath
       *            the parent directory.
       * @throws DirectoryNotFoundException
       *             if the directory does not exist.
       * @return The list of sub-directories.
       */
      public static List<File> getSubDirectories( String strRoot, String strDirectoryRelativePath ) throws DirectoryNotFoundException
      {
          // Files' list init
          ArrayList<File> listFiles = new ArrayList<>( );
  
          // Directory path
          String strDirectory = strRoot + strDirectoryRelativePath;
  
          // Directory
          File fDirectory = new File( strDirectory );
  
          if ( !fDirectory.exists( ) )
          {
              throw new DirectoryNotFoundException( );
          }
  
          File [ ] files = fDirectory.listFiles( );
          if ( ArrayUtils.isEmpty( files ) )
          {
              return listFiles;
          }
 
         for ( int i = 0; i < files.length; i++ )
         {
             File file = files [i];
 
             if ( file.isDirectory( ) )
             {
                 listFiles.add( file );
             }
         }
 
         return listFiles;
     }
 
     /**
      * Returns the files of a directory, alphabetically ordered.
      *
      * @param strRoot
      *            The root directory
      * @param strDirectoryRelativePath
      *            The directory's path relative to the root directory.
      * @throws DirectoryNotFoundException
      *             if the directory does not exist.
      * @return The list of files.
      */
     public static List<File> getFiles( String strRoot, String strDirectoryRelativePath ) throws DirectoryNotFoundException
     {
         // Use a treeset to order files with a comparator
         TreeSet<File> set = new TreeSet<>( new FileNameComparator( ) );
 
         // Directory path
         String strDirectory = strRoot + strDirectoryRelativePath;
 
         // Directory
         File fDirectory = new File( strDirectory );
 
         if ( !fDirectory.exists( ) )
         {
             throw new DirectoryNotFoundException( );
         }
 
         File [ ] files = fDirectory.listFiles( );
         if ( ArrayUtils.isEmpty( files ) )
         {
             return new ArrayList<>( set );
         }
 
         for ( int i = 0; i < files.length; i++ )
         {
             File file = files [i];
 
             if ( file.isFile( ) )
             {
                 set.add( file );
             }
         }
 
         // Convert into a list to preserve the order
         return new ArrayList<>( set );
     }
 
     /**
      * Return the mimetype of the file depending of his extension and the mime.types file
      * 
      * @param strFilename
      *            the file name
      * @return the file mime type
      */
     public static String getMIMEType( String strFilename )
     {
         try
         {
             MimetypesFileTypeMap mimeTypeMap = new MimetypesFileTypeMap( AppPathService.getWebAppPath( ) + File.separator + FILE_MIME_TYPE );
 
             return mimeTypeMap.getContentType( strFilename.toLowerCase( ) );
         }
         catch( IOException e )
         {
             AppLogService.error( e.getMessage( ), e );
 
             return DEFAULT_MIME_TYPE;
         }
     }
 }