<?php

/**
 * Function to generate a CSV file listing the session membership for the specified study group
 */
function booking_studygroups_csv_report($group_id) {
  global $event;
 
	//verify that $group_id is a number
	if (! preg_match('/^[0-9]+$/', $group_id)) {
		drupal_set_message("Error: Invalid study group ID '" . $group_id . "' supplied. Unable to view group membership.", 'error', FALSE);
		drupal_goto('admin/booking/studygroups');
		return "";
	}
	
  //set options for the CSV file
	$name = 'bookings-studygroup-' . $group_id . '-' . format_date(time(), 'custom', 'Y-m-d-His');
	$filename = file_directory_temp() . '/' . $name;
	$csv = '';
	$delimiter = ',';
	$enclosure = '"';
	$encloseAll = true;
	$nullToMysqlNull = true;
  $delimiter_esc = preg_quote($delimiter, '/');
  $enclosure_esc = preg_quote($enclosure, '/');
  
  $header_array = array();
  $data_array = array();
  
	//is this study group a readings group?
  // @todo do we even care?
  /*
	if ($group_id == variable_get('booking_readinggroup_id','7')) {
		$is_reading_group = TRUE;
	}
  else {
    $is_reading_group = FALSE;
  }  
	*/
  
  // @todo
  // get a listing of all the registrations so we can lookup people's names based on their node id
  
  //get the list of study group sessions
	$studygroups_query = db_query("SELECT * FROM {booking_studygroup_list} WHERE booking_eventid = :eid and sid = :sid",
						array(':eid' => $event->eid, ':sid' => $group_id));
  $studygroups = $studygroups_query->fetchAllAssoc('sid');
  
  //get the list of study group session memberships
  $session_members_query = db_query("SELECT * FROM {booking_studygroup_mapping} WHERE booking_studygroup_id = :sid",
						array(':sid' => $group_id));
  $session_members = $session_members_query->fetchAll();

  //set up the column headings
  foreach ($studygroups as $studygroup) {
    $header_array[] = $studygroup->sid;
  }	  
  $header = implode( $delimiter, $header_array );
  $csv .= $header . "\n";
  
  //calculate the row data
  foreach ($session_members as $member) {
    if (! isset($data_array[$member->booking_session_id])) {
      $data_array[$member->booking_session_id] = new stdClass();
    }
    // @todo 
    // lookup the actual name and put this instead of just the node id 
    
    $data_array[$member->booking_session_id][] = $member->booking_node_id;
  }
  
  $out = fopen('php://output', 'w');
  fputcsv2 ($out, $data_array);
  fclose($out);
}

/**
 * Function taken from http://php.net/manual/en/function.fputcsv.php#87120
 */
function fputcsv2 ($fh, array $fields, $delimiter = ',', $enclosure = '"', $mysql_null = false) { 
    $delimiter_esc = preg_quote($delimiter, '/'); 
    $enclosure_esc = preg_quote($enclosure, '/'); 

    $output = array(); 
    foreach ($fields as $field) { 
        if ($field === null && $mysql_null) { 
            $output[] = 'NULL'; 
            continue; 
        } 

        $output[] = preg_match("/(?:${delimiter_esc}|${enclosure_esc}|\s)/", $field) ? ( 
            $enclosure . str_replace($enclosure, $enclosure . $enclosure, $field) . $enclosure 
        ) : $field; 
    } 

    fwrite($fh, join($delimiter, $output) . "\n"); 
}