<?php

require_once('Transformer.php');

class ICalendar extends Transformer {

  public function transform() {
    // make sure we have the required arguments
    if (empty($this->extraArgs['startDateField']))
      throw new MissingArgumentsException(array('startDateField'));
    
    // get the dom
    $xmlDoc  = new DOMDocument();
    if (!$xmlDoc->loadXML($this->xmlContents)) {
      throw new Exception("Unable to DOMify XML (XML looks like: ".$this->xmlContents.')');
    }
    $this->xpath   = new DOMXPath($xmlDoc);
    
    // issue the correct headers
    header("Content-type: text/Calendar");
    header("Content-Disposition: inline; filename=cal.ics");
    
    // maybe there was an error, so let's check it
    $messages = $this->xpath->query("/results/message");
    if ($messages->length > 0) {
      echo "BEGIN:VCALENDAR\n";
      echo "PRODID:Dapper iCalendar Generator\n";
      echo "X-WR-CALNAME:Error\n";
      echo "VERSION:2.0\n";
      echo "BEGIN:VEVENT\n";
      echo "DTSTART;VALUE=DATE:".date('Ymd')."\n";
      echo "DTEND;VALUE=DATE:".date('Ymd')."\n";
      $summary = $messages->item(0)->nodeValue;
      echo "SUMMARY:$summary\n";
      echo "DESCRIPTION;ENCODING=QUOTED-PRINTABLE:$summary\n";
      echo "END:VEVENT\n";
      echo "END:VCALENDAR\n";
      exit;
    }

    echo "BEGIN:VCALENDAR\n";
    echo "PRODID:Dapper iCalendar Generator\n";
    echo "X-WR-CALNAME:".$this->xpath->query("/elements/dapper/dappTitle")->item(0)->nodeValue."\n";
    echo "VERSION:2.0\n";

    // grab all the start date fields
    $dates = $xmlDoc->getElementsByTagName($this->extraArgs['startDateField']);
    for ($i = 0; $i < $dates->length; $i++) {
      $startDate   = $this->formatDate($dates->item($i)->nodeValue);
      $endDate     = null;
      $location    = null;
      $summary     = "No Title";
      $description = "No description";
      
      if (isset($startDate)) {
        echo "BEGIN:VEVENT\n";
        if (strlen($startDate) == 8)
          echo "DTSTART;VALUE=DATE:$startDate\n";
        else
          echo "DTSTART:$startDate\n";        
        
        // now deal with additional fields (only works with groups
        $groupNode = $dates->item($i)->parentNode;
        if ($groupNode->getAttribute('type') == 'group') {
          
          foreach (array('endDateField', 'descriptionField', 'titleField', 'locationField') as $arg) {
            if (!empty($this->extraArgs[$arg])) {
              $matchingKids = $groupNode->getElementsByTagName($this->extraArgs[$arg]);
              if ($matchingKids && $matchingKids->item(0) && $matchingKids->item(0)->nodeValue) {
                $nodeValue = $matchingKids->item(0)->nodeValue;
                switch ($arg) {
                  case 'titleField':
                    $summary = $matchingKids->item(0)->nodeValue;
                    break;
                  case 'descriptionField':
                    $description = preg_replace('/[\n\r\f]/','=0D=OA=', $matchingKids->item(0)->nodeValue);
                    break;
                  case 'endDateField':
                    $endDate = $this->formatDate($matchingKids->item(0)->nodeValue);
                    break;
                  case 'descriptionField':
                    $location = preg_replace('/[\n\r\f]/','=0D=OA=', $matchingKids->item(0)->nodeValue);
                    break;
                }
              }
            }
          }
        }
        
        if (!isset($endDate))
          $endDate = $startDate;        
        if (strlen($endDate) == 8)
          echo "DTEND;VALUE=DATE:$endDate\n";
        else
          echo "DTEND:$endDate\n";

        echo "SUMMARY:$summary\n";
        echo "DESCRIPTION;ENCODING=QUOTED-PRINTABLE:$description\n";
        
        if (isset($location))
          echo "LOCATION:$location\n";
        
        echo "END:VEVENT\n";
      }
    }
    
    echo "END:VCALENDAR\n";
  }

  public static function getDetails() {
    $details = array();
    
    $details['args']['startDateField']   = array('type'     => DAPP_FIELD,
                                                 'required' => true,
                                                 'display'  => 'Event Start Date');

    $details['args']['endDateField']     = array('type'     => DAPP_FIELD,
                                                 'required' => false,
                                                 'display'  => 'Event End Date');

    $details['args']['titleField']       = array('type'     => DAPP_FIELD,
                                                 'required' => false,
                                                 'display'  => 'Even Title');

    $details['args']['descriptionField'] = array('type'     => DAPP_FIELD,
                                                 'required' => false,
                                                 'display'  => 'Event Description');

    $details['args']['locationField']    = array('type'     => DAPP_FIELD,
                                                 'required' => false,
                                                 'display'  => 'Event Location');
    $details['description']   = 'Transforms the output of a Dapp into an '.
                                'iCalendar which can be used in Google Calendar, '.
                                'Sunbird, iCal, and other programs.';
    
    return $details;
  }

  function formatDate($stringDate) {
    if (strtotime($stringDate) !== false) {
      if (date('His', strtotime($stringDate)) == '000000')
        $date = date('Ymd', strtotime($stringDate));
      else
        $date = date('Ymd\THis', strtotime($stringDate));
      return $date;
    }
    
    return null;
  }

}

?>