/**
    * This file is part of the equanda project.
    *
    * The contents of this file are subject to the Mozilla Public License Version 1.1 (the "License");
    * you may not use this file except in compliance with the License.
    * You may obtain a copy of the License at http://www.mozilla.org/MPL/
    *
    * Software distributed under the License is distributed on an "AS IS" basis, WITHOUT WARRANTY OF
    * ANY KIND, either express or implied. See the License for the specific language governing rights and
   * limitations under the License.
   *
   * Alternatively, the contents of this file may be used under the terms of
   * either the GNU General Public License Version 2 or later (the "GPL"), or
   * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
   * in which case the provisions of the GPL or the LGPL are applicable instead
   * of those above. If you wish to allow use of your version of this file only
   * under the terms of either the GPL or the LGPL, and not to allow others to
   * use your version of this file under the terms of the MPL, indicate your
   * decision by deleting the provisions above and replace them with the notice
   * and other provisions required by the GPL or the LGPL. If you do not delete
   * the provisions above, a recipient may use your version of this file under
   * the terms of any one of the MPL, the GPL or the LGPL.
   */
  
  package org.equanda.tapestry5.components;
  
  import org.apache.tapestry5.MarkupWriter;
  import org.apache.tapestry5.RenderSupport;
  import org.apache.tapestry5.annotations.*;
  import org.apache.tapestry5.ioc.annotations.Inject;
  import org.apache.tapestry5.services.Environment;
  import org.equanda.tapestry5.base.PagerConfig;
  
  import java.util.List;
  
  /**
   * Equanda modification of {@link org.apache.tapestry5.corelib.components.GridPager}
   * 
   * @author <a href="mailto:vladimir.tkachenko@gmail.com">Vladimir Tkachenko</a>
   */
  @IncludeStylesheet( value = { "classpath:/org/equanda/tapestry5/resources/jspager.css" } )
  @IncludeJavaScriptLibrary( { "${tapestry.scriptaculous}/prototype.js",
                               "classpath:/org/equanda/tapestry5/resources/t5equanda.js" } )
  public class JSPager
  {
      /** The source of the data displayed by the JSPagedLoop */
      @Parameter
      private List<Object> source;
  
      /** The number of rows displayed per page. */
      @Parameter
      private int rowsPerPage;
  
      /**
       * Number of pages before and after the current page in the range. The pager always displays links for 2 * range + 1
       * pages, unless that's more than the total number of available pages.
       */
      @Parameter( "5" )
      private int range;
  
      // private int maxPages;
  
      @Environmental
      private RenderSupport renderSupport;
  
      @Inject
      private Environment environment;
  
      public PagerConfig getConfig()
      {
          JSPagedLoop pagedLoop = environment.peek( JSPagedLoop.class );
  
          int availableRows = source.size() - pagedLoop.getAddedRowCount();
  
          String clientId = pagedLoop.getClientId().toLowerCase();
  
          int maxPages = ( ( availableRows - 1 ) / rowsPerPage ) + 1;
  
          return new PagerConfig( range, maxPages, rowsPerPage, 0, pagedLoop.getCurrentPage(), source.size(), pagedLoop
              .getAddedRowCount(), pagedLoop.getAdditionalRowCount(), pagedLoop.getCurrentPageFieldName(), pagedLoop
              .getAddedRowFieldName(), "eqpl_" + clientId, "eqplr_" + clientId, "eqplal_" + clientId, "eqplab_"
              + clientId, clientId );
      }
  
      @BeginRender
      void render( MarkupWriter writer )
      {
          JSPagedLoop pagedLoop = environment.peek( JSPagedLoop.class );
  
          if ( pagedLoop != null )
          {
              String clientId = pagedLoop.getClientId().toLowerCase();
  
              writer.element( "div", "class", "eqplp eqpl_" + clientId );
              
              PagerConfig config = getConfig();
              
              showPage( pagedLoop.getCurrentPage(), config, writer );
              writer.end();
 
             renderSupport.addScript( "eqJsplC.%s = %s;", clientId, config.getJSONObject() );
             renderSupport.addScript( "eqChAL( eqJsplC.%s );", clientId );
         }
     }
 
     private void showPage( int pageIdx, PagerConfig config, MarkupWriter writer )
     {
         if ( pageIdx > 0 )
         {
             config.setCurrentPage( pageIdx );
         }
 
         if ( config.getCurrentPage() == 0 )
         {
             config.setCurrentPage( 1 );
         }
 
         int availableRows = config.getRowCount() - config.getAdditionalRowCount() + config.getAddedRowCount();
 
         config.setMaxPages( ( ( availableRows - 1 ) / config.getRowsPerPage() ) + 1 );
 
         if ( config.getMaxPages() > 0 && config.getCurrentPage() > config.getMaxPages() )
         {
             config.setCurrentPage( config.getMaxPages() );
         }
 
         if ( config.getMaxPages() < 2 )
         {
             return;
         }
 
         config.setLastIndex( 0 );
 
         for ( int i = 1; i <= 2; i++ )
         {
             equandaWritePageLink( i, config, writer );
         }
 
         int low = config.getCurrentPage() - config.getRange();
         int high = config.getCurrentPage() + config.getRange();
 
         if ( low < 1 )
         {
             low = 1;
             high = 2 * config.getRange() + 1;
         }
         else
         {
             if ( high > config.getMaxPages() )
             {
                 high = config.getMaxPages();
                 low = high - 2 * config.getRange();
             }
         }
 
         for ( int i = low; i <= high; i++ )
         {
             equandaWritePageLink( i, config, writer );
         }
 
         for ( int i = config.getMaxPages() - 1; i <= config.getMaxPages(); i++ )
         {
             equandaWritePageLink( i, config, writer );
         }
     }
 
     private void equandaWritePageLink( int pageIndex, PagerConfig config, MarkupWriter writer )
     {
         if ( pageIndex < 1 || pageIndex > config.getMaxPages() )
             return;
 
         if ( pageIndex <= config.getLastIndex() )
             return;
 
         if ( pageIndex != config.getLastIndex() + 1 )
         {
             writer.element( "div" );
             writer.write( "..." );
             writer.end();
         }
 
         config.setLastIndex( pageIndex );
 
         if ( pageIndex == config.getCurrentPage() )
         {
             writer.element( "span", "class", "eqplc" );
             writer.write( "" + pageIndex );
             writer.end();
             return;
         }
 
         writer.element( "a", "href", "javascript:;", "onclick", String.format( "eqShwPg( %s, %s )", pageIndex,
             "eqJsplC." + config.getName() ), "title", "Goto Page " + pageIndex );
         writer.write( "" + pageIndex );
         writer.end();
     }
 
 }