<?PHP

  require_once ('twIf/object/access.php');
  require_once ('twIf/widget/control.php');
  
  require_once ('Spreadsheet/Excel/Writer.php');
  require_once ('Spreadsheet/Excel/Writer/Worksheet.php');
  
  /**
   * Excel Converter
   * =============
   * Convert a set of Objects into Excel-Format
   * 
   * @class twIf_Convert_Excel
   * @extends twIf_Object_Access
   * @package twIf
   * @revision 01
   * @author Bernd Holzmueller <bernd@tiggerswelt.net>
   **/
  class twIf_Convert_Excel extends twIf_Object_Access {
    const MIME_TYPE = 'application/vnd.ms-excel';
    const SUFFIX = 'xls';
    
    // {{{ export
    /**
     * @param array $Handles
     * @param array $Fields
     * @param string $WorksheetName (optional)
     * @param object $Workbook (optional)
     * 
     * @access public
     * @return string
     **/
    public static function export ($Handles, $Fields, $WorksheetName = null, $Workbook = null, $Finalize = null) {
      // Setup the export-destination
      if (!is_object ($Workbook)) {
        if (isset ($_SERVER ['TMPDIR']))
          $tmpDir = $_SERVER ['TMPDIR'];
        elseif (isset ($_ENV ['TMPDIR']))
          $tmpDir = $_ENV ['TMPDIR'];
        elseif (is_writeable ('/tmp'))
          $tmpDir = '/tmp';
        else
          return false;
        
        $fn = tempnam ($tmpDir, 'twIfConvertExcelExport');
        $Workbook = new Spreadsheet_Excel_Writer ($fn);
        $Finalize = true;
      } elseif ($Finalize === null)
        $Finalize = false;
      
      if ($WorksheetName === null) {
        $WorksheetName = 'twIf_Convert_Excel';
        
        foreach ($Handles as $Handle)
          if (is_object ($Handle)) {
            $WorksheetName .= ' / ' . get_class ($Handle);
            break;
          }
      }
      
      $Worksheet = $Workbook->addWorksheet ($WorksheetName);
      
      $formatHeader = $Workbook->addFormat ();
      $formatHeader->setBold ();
      $formatHeader->setBottom (1);
      
      // Retrive the first handle
      foreach ($Handles as $Handle)
        if (is_object ($Handle))
          break;
      
      // Generate the Excel-Header
      $Column = 0;
      $ColumnFormats = array ();
      
      foreach ($Fields as $ID=>$Field) {
        $Fields [$ID]['def'] = $Definition = parent::parseFieldDef ($ID, $Field, $Handle, 0, true);
        
        switch ($Definition ['Type']) {
          case twIf_Widget_Control::TYPE_DATE:
          case twIf_Widget_Control::TYPE_DATE_FUTURE:
          case twIf_Widget_Control::TYPE_DATE_YEARMONTH:
          case twIf_Widget_Control::TYPE_DATE_YEARMONTH_FUTURE:
            $ColumnFormats [$Column] = $formatDate = $Workbook->addFormat ();
            $formatDate->setNumFormat ('D-MMM-YY');
            
            break;
            
          # case twIf_Widget_Control::
          
          default:
            $ColumnFormats [$Column] = null;
        }
        
        $Worksheet->write (0, $Column++, utf8_decode (isset ($Definition ['Caption']) ? $Definition ['Caption'] : $ID), $formatHeader);
      }
      
      // Output the handles
      $Row = 1;
      
      foreach ($Handles as $Handle) {
        $Column = 0;
        
        // Output the values
        foreach ($Fields as $Field) {
          if ($ColumnFormats [$Column] == $formatDate)
            $Worksheet->write ($Row, $Column, number_format ((parent::formatNative ($Handle, $Field ['def']) + 2209165200) / 86400, 5, '.', ''), $ColumnFormats [$Column]);
          else
            $Worksheet->write ($Row, $Column, utf8_decode (parent::getFieldValue ($Handle, $Field ['def'])), $ColumnFormats [$Column]);
          
          $Column++;
        }
        
        $Row++;
      }
      
      // Finalize the Workbook
      if (!$Finalize)
        return true;
      
      $Workbook->close ();
      
      // Check wheter the file is there
      if (!is_file ($Workbook->_filename))
        return false;
      
      // Try to open it
      if (!is_resource ($f = fopen ($Workbook->_filename, 'r')))
        return false;
      
      $buf = fread ($f, filesize ($Workbook->_filename));
      fclose ($f);
      
      return $buf;
    }
    // }}}
  }

?>