/*
    * 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.http;
  
  import fr.paris.lutece.portal.service.html.EncodingService;
  import fr.paris.lutece.portal.service.util.AppLogService;
  import fr.paris.lutece.portal.web.upload.MultipartHttpServletRequest;
  import fr.paris.lutece.portal.web.upload.NormalizeFileItem;
  
  import org.apache.commons.fileupload.FileItem;
  import org.apache.commons.fileupload.FileItemIterator;
  import org.apache.commons.fileupload.FileItemStream;
  import org.apache.commons.fileupload.FileUploadBase.SizeLimitExceededException;
  import org.apache.commons.fileupload.FileUploadException;
  import org.apache.commons.fileupload.disk.DiskFileItemFactory;
  import org.apache.commons.fileupload.servlet.ServletFileUpload;
  import org.apache.commons.lang3.StringUtils;
  
  import java.io.UnsupportedEncodingException;
  
  import java.util.ArrayList;
  import java.util.HashMap;
  import java.util.List;
  import java.util.Map;
  import java.util.Optional;
  
  import javax.servlet.http.HttpServletRequest;
  
  /**
   *
   * MultipartUtil
   *
   */
  public final class MultipartUtil
  {
      /**
       * Private constructor
       */
      private MultipartUtil( )
      {
      }
  
      /**
       * Check if the given HTTP request has multipart content
       *
       * @param request
       *            the HTTP request
       * @return true if it has multipart content, false otherwise
       */
      public static boolean isMultipart( HttpServletRequest request )
      {
          return ServletFileUpload.isMultipartContent( request );
      }
  
      /**
       * Convert a HTTP request to a {@link MultipartHttpServletRequest}
       *
       * @param nSizeThreshold
       *            the size threshold
       * @param nRequestSizeMax
       *            the request size max
       * @param bActivateNormalizeFileName
       *            true if the file name must be normalized, false otherwise
       * @param request
       *            the HTTP request
       * @return a {@link MultipartHttpServletRequest}, null if the request does not have a multipart content
       * @throws SizeLimitExceededException
       *             exception if the file size is too big
      * @throws FileUploadException
      *             exception if an unknown error has occurred
      */
     public static MultipartHttpServletRequest convert( int nSizeThreshold, long nRequestSizeMax, boolean bActivateNormalizeFileName,
             HttpServletRequest request ) throws FileUploadException
     {
         if ( !isMultipart( request ) )
         {
             return null;
         }
 
         // Create a factory for disk-based file items
         DiskFileItemFactory factory = new DiskFileItemFactory( );
 
         // Set factory constraints
         factory.setSizeThreshold( nSizeThreshold );
 
         // Create a new file upload handler
         ServletFileUpload upload = new ServletFileUpload( factory );
 
         // Set overall request size constraint
         upload.setSizeMax( nRequestSizeMax );
 
         // get encoding to be used
         String strEncoding = Optional.ofNullable( request.getCharacterEncoding( ) ).orElse( EncodingService.getEncoding( ) );
 
         Map<String, List<FileItem>> mapFiles = new HashMap<>( );
         Map<String, String [ ]> mapParameters = new HashMap<>( );
 
         List<FileItem> listItems;
 
         try {
             listItems = upload.parseRequest(request);
         }
         catch( SizeLimitExceededException e )
         {
             closeInputStream( upload, request );
             throw e;
         }
 
         // Process the uploaded items
         for ( FileItem item : listItems )
         {
             processItem( item, strEncoding, bActivateNormalizeFileName, mapFiles, mapParameters );
         }
 
         return new MultipartHttpServletRequest( request, mapFiles, mapParameters );
     }
 
     /**
      * Close the inputStream of the request
      * @param upload
      * @param request
      */
     private static void closeInputStream( ServletFileUpload upload, HttpServletRequest request)
     {
         try {
             upload.setSizeMax(-1);
             FileItemIterator fileiterator = upload.getItemIterator(request);
 
             while (fileiterator.hasNext()) 
             {
                 FileItemStream item = fileiterator.next();
                 item.openStream().close();
             }
         }
         catch (Exception e)
         {
             AppLogService.error( "error occured during closing the stream" , e);
         }
 
     }
 
     private static void processItem( FileItem item, String strEncoding, boolean bActivateNormalizeFileName, Map<String, List<FileItem>> mapFiles,
             Map<String, String [ ]> mapParameters )
     {
         if ( item.isFormField( ) )
         {
             String strValue = StringUtils.EMPTY;
 
             if ( item.getSize( ) > 0 )
             {
                 try
                 {
                     strValue = item.getString( strEncoding );
                 }
                 catch( UnsupportedEncodingException ex )
                 {
                     // if encoding problem, try with system encoding
                     strValue = item.getString( );
                 }
             }
 
             // check if item of same name already in map
             String [ ] curParam = mapParameters.get( item.getFieldName( ) );
 
             if ( curParam == null )
             {
                 // simple form field
                 mapParameters.put( item.getFieldName( ), new String [ ] {
                         strValue
                 } );
             }
             else
             {
                 // array of simple form fields
                 String [ ] newArray = new String [ curParam.length + 1];
                 System.arraycopy( curParam, 0, newArray, 0, curParam.length );
                 newArray [curParam.length] = strValue;
                 mapParameters.put( item.getFieldName( ), newArray );
             }
         }
         else
         {
             // multipart file field, if the parameter filter ActivateNormalizeFileName is
             // set to true
             // all file name will be normalize
             FileItem fileItem = bActivateNormalizeFileName ? new NormalizeFileItem( item ) : item;
             List<FileItem> listFileItem = mapFiles.get( fileItem.getFieldName( ) );
 
             if ( listFileItem != null )
             {
                 listFileItem.add( fileItem );
             }
             else
             {
                 listFileItem = new ArrayList<>( 1 );
                 listFileItem.add( fileItem );
                 mapFiles.put( fileItem.getFieldName( ), listFileItem );
             }
         }
     }
 }