/*
    * 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.plugins.genericattributes.service.upload;
  
  import java.util.ArrayList;
  import java.util.Iterator;
  import java.util.List;
  import java.util.Locale;
  import java.util.Map;
  import java.util.concurrent.ConcurrentHashMap;
  import java.util.regex.Matcher;
  import java.util.regex.Pattern;
  
  import javax.servlet.http.HttpServletRequest;
  import javax.servlet.http.HttpSession;
  
  import org.apache.commons.fileupload.FileItem;
  import org.apache.commons.lang3.StringUtils;
  
  import fr.paris.lutece.plugins.asynchronousupload.service.AbstractAsynchronousUploadHandler;
  import fr.paris.lutece.plugins.genericattributes.business.Entry;
  import fr.paris.lutece.plugins.genericattributes.business.EntryHome;
  import fr.paris.lutece.plugins.genericattributes.business.GenericAttributeError;
  import fr.paris.lutece.plugins.genericattributes.service.entrytype.EntryTypeServiceManager;
  import fr.paris.lutece.plugins.genericattributes.service.entrytype.IEntryTypeService;
  import fr.paris.lutece.portal.service.i18n.I18nService;
  import fr.paris.lutece.portal.service.util.AppException;
  import fr.paris.lutece.util.filesystem.UploadUtil;
  
  /**
   * Abstract class to manage uploaded files for generic attributes entries of type files
   */
  public abstract class AbstractGenAttUploadHandler extends AbstractAsynchronousUploadHandler
  {
      private static final String PREFIX_ENTRY_ID = IEntryTypeService.PREFIX_ATTRIBUTE;
      private static final Pattern PATTERN_PREFIX_ENTRY_ID = Pattern.compile( "[^0-9]+([0-9]+)$" );
  
      // Error messages
      private static final String ERROR_MESSAGE_UNKNOWN_ERROR = "genericattributes.message.unknownError";
  
      /** <sessionId,<fieldName,fileItems>> */
      /** contains uploaded file items */
      private static Map<String, Map<String, List<FileItem>>> _mapAsynchronousUpload = new ConcurrentHashMap<>( );
  
      /**
       * {@inheritDoc}
       */
      @Override
      public String canUploadFiles( HttpServletRequest request, String strFieldName, List<FileItem> listFileItemsToUpload, Locale locale )
      {
          if ( StringUtils.isNotBlank( strFieldName ) && ( strFieldName.length( ) > PREFIX_ENTRY_ID.length( ) ) )
          {
              String sessionId = getCustomSessionId( request.getSession( ) );
              initMap( sessionId, strFieldName );
  
              String strIdEntry = getEntryIdFromFieldName( strFieldName );
  
              if ( StringUtils.isEmpty( strIdEntry ) || !StringUtils.isNumeric( strIdEntry ) )
              {
                  return I18nService.getLocalizedString( ERROR_MESSAGE_UNKNOWN_ERROR, locale );
              }
  
              int nIdEntry = Integer.parseInt( strIdEntry );
              Entry entry = EntryHome.findByPrimaryKey( nIdEntry );
  
              List<FileItem> listUploadedFileItems = getListUploadedFiles( strFieldName, request.getSession( ) );
  
              if ( entry != null )
             {
                 GenericAttributeError error = EntryTypeServiceManager.getEntryTypeService( entry ).canUploadFiles( entry, listUploadedFileItems,
                         listFileItemsToUpload, locale );
 
                 if ( error != null )
                 {
                     return error.getErrorMessage( );
                 }
 
                 return null;
             }
         }
 
         return I18nService.getLocalizedString( ERROR_MESSAGE_UNKNOWN_ERROR, locale );
     }
 
     /**
      * {@inheritDoc}
      */
     @Override
     public List<FileItem> getListUploadedFiles( String strFieldName, HttpSession session )
     {
         if ( StringUtils.isBlank( strFieldName ) )
         {
             throw new AppException( "id field name is not provided for the current file upload" );
         }
 
         String sessionId = getCustomSessionId( session );
 
         initMap( sessionId, strFieldName );
 
         // find session-related files in the map
         Map<String, List<FileItem>> mapFileItemsSession = _mapAsynchronousUpload.get( sessionId );
 
         return mapFileItemsSession.get( strFieldName );
     }
 
     /**
      * {@inheritDoc}
      */
     @Override
     public void addFileItemToUploadedFilesList( FileItem fileItem, String strFieldName, HttpServletRequest request )
     {
         // This is the name that will be displayed in the form. We keep
         // the original name, but clean it to make it cross-platform.
         String strFileName = UploadUtil.cleanFileName( fileItem.getName( ).trim( ) );
 
         String sessionId = getCustomSessionId( request.getSession( ) );
         initMap( sessionId, strFieldName );
 
         // Check if this file has not already been uploaded
         List<FileItem> uploadedFiles = getListUploadedFiles( strFieldName, request.getSession( ) );
 
         if ( uploadedFiles != null )
         {
             boolean bNew = true;
 
             if ( !uploadedFiles.isEmpty( ) )
             {
                 Iterator<FileItem> iterUploadedFiles = uploadedFiles.iterator( );
 
                 while ( bNew && iterUploadedFiles.hasNext( ) )
                 {
                     FileItem uploadedFile = iterUploadedFiles.next( );
                     String strUploadedFileName = UploadUtil.cleanFileName( uploadedFile.getName( ).trim( ) );
                     // If we find a file with the same name and the same
                     // length, we consider that the current file has
                     // already been uploaded
                     bNew = !( StringUtils.equals( strUploadedFileName, strFileName ) && ( uploadedFile.getSize( ) == fileItem.getSize( ) ) );
                 }
             }
 
             if ( bNew )
             {
                 uploadedFiles.add( fileItem );
             }
         }
     }
 
     @Override
     public void removeSessionFiles( HttpSession session )
     {
         String sessionId = (String) session.getAttribute( PARAM_CUSTOM_SESSION_ID );
         if ( sessionId != null )
         {
             _mapAsynchronousUpload.remove( sessionId );
         }
 
     }
 
     /**
      * Build the field name from a given id entry i.e. : form_1
      * 
      * @param strIdEntry
      *            the id entry
      * @return the field name
      */
     protected String buildFieldName( String strIdEntry )
     {
         return PREFIX_ENTRY_ID + strIdEntry;
     }
 
     /**
      * Get the id of the entry associated with a given field name
      * 
      * @param strFieldName
      *            The name of the field
      * @return The id of the entry
      */
     protected String getEntryIdFromFieldName( String strFieldName )
     {
         if ( StringUtils.isEmpty( strFieldName ) || ( strFieldName.length( ) < PREFIX_ENTRY_ID.length( ) ) )
         {
             return null;
         }
 
         Matcher matcher = PATTERN_PREFIX_ENTRY_ID.matcher( strFieldName );
         if ( matcher.find( ) )
         {
             return matcher.group( 1 );
         }
 
         return null;
     }
 
     /**
      * Init the map
      * 
      * @param strSessionId
      *            the session id
      * @param strFieldName
      *            the field name
      */
     private void initMap( String strSessionId, String strFieldName )
     {
         // find session-related files in the map
         Map<String, List<FileItem>> mapFileItemsSession = _mapAsynchronousUpload.get( strSessionId );
 
         // create map if not exists
         if ( mapFileItemsSession == null )
         {
             synchronized( this )
             {
                 // Ignore double check locking error : assignation and instanciation of objects are separated.
                 mapFileItemsSession = _mapAsynchronousUpload.computeIfAbsent( strSessionId, s -> new ConcurrentHashMap<>( ) );
             }
         }
 
         mapFileItemsSession.computeIfAbsent( strFieldName, s -> new ArrayList<>( ) );
     }
 }