<?php
// $Id: booking.helper.inc,v 0.1 2011/07/12

/**
 * Helper function to perform some validity checking of email addresses
 */
function _valid_email_address($email) {
	//firstly use the built-in function to validate the format
	if (! valid_email_address($email))
	  return false;
	//now check the domain exists

  if (preg_match('/^(.*?)\@(.*)/', $email, $matches)) {
    //watchdog('booking', 'Email address checking: @info', array('@info' => var_export($matches, TRUE)));
	if (! checkdnsrr($matches[2], "MX"))
	  return 0;
	return 1;
  }
  //watchdog('booking', 'Email address checking doesnt match');
  return 0;
}

/**
 * Helper function to perform some validity checking of Medicare Numbers
 * Based on http://dyball.wordpress.com/2007/12/05/validation-of-medicare-numbers/
 */
function _valid_medicare_number($input) {
    //strip any whitespace
    $medicare = preg_replace( '/\s+/', '', $input );
    if (is_numeric($medicare) && strlen($medicare) >= 9 && $medicare > 0)
    {
        $check_digit = $medicare[0] + (3 * $medicare[1]) + (7 * $medicare[2]) + (9 * $medicare[3])
                        + $medicare[4] + (3 * $medicare[5]) + (7 * $medicare[6]) + (9 * $medicare[7]);

        if (($check_digit % 10) == $medicare[8])
        {
            watchdog('booking', 'Medicare number (!mca) validates since check digit !check matches remainder from !remainder',
                    array('!mca' => $input, '!check' => $medicare[8], '!remainder' => $check_digit));
            return TRUE;
        }
        else
        {
            watchdog('booking', 'Medicare number (!mca) does not validate since check digit !check does not match remainder from !remainder',
                    array('!mca' => $input, '!check' => $medicare[8], '!remainder' => $check_digit));
            return FALSE;
        }
    }
    else
    {
        watchdog('booking', 'Medicare number (!mca) does not validate since it is either non-numeric or too short',
                array('!mca' => $input));
        return FALSE;
    }
}
/**
 * Helper function to perform some validity checking of a passport number
 * Based on http://dyball.wordpress.com/2007/04/12/validation-of-passport-numbers/
 * @param $input string containing passport number to be verified
 * @return boolean indicating if passport number is valid
 */
function _valid_passport_number($input) {
	//strip whitespace
    $passport = preg_replace( '/\s+/', '', $input );	
	//check for a match
	if (preg_match('/^[a-zA-Z]\d{7}$/', $input, $matches)) {
        watchdog('booking', 'Passport number "!passnum" validates since it passed our regexp',
                array('!passnum' => $input));		
		return TRUE;
	}
    watchdog('booking', 'Passport number "!passnum" fails to validate',
            array('!passnum' => $input));	
	return FALSE;
}

function _valid_phone_number($input)
{
    //strip any whitespace
    $number = preg_replace( '/\s+/', '', $input );
    //strip any non-numeric characters
    $number = preg_replace('/\D+/','', $number);

    if (is_numeric($number))
        return TRUE;
    else
        return FALSE;

    /*
    if (preg_match('^(?:\+61|0061|0)(\d{3})\s*(\d{3})\s*(\d{3})$', $number, $matches))
    {

    }
    */
}


/**
 * Helper function to check whether the number of registrations for the current event have reached their defined maximum size
 */
function _booking_check_bookings_full()
{
	global $event;
	$waitinglist_query = db_query("SELECT count(*) as num_ppl FROM {booking_person} where booking_event_id = :eventid and booking_status = 1",
						array(':eventid' => $event->eid))
			->fetchObject();
	//check the number of people registered against the defined max
	if ($waitinglist_query->num_ppl >= variable_get('booking_regn_limit', 350))
	{
		watchdog('booking', 'There are !num people booked in, which is greater than or equal to the limit of !limit.',
			array('!num' => $waitinglist_query->num_ppl, '!limit' => variable_get('booking_regn_limit', 350) ));
		return true;
	}
	else
	{
		watchdog('booking', 'There are !num people booked in, which is less than the limit of !limit.',
			array('!num' => $waitinglist_query->num_ppl, '!limit' => variable_get('booking_regn_limit', 350) ));		
		return false;
	}
}

/**
 * Helper function to check who is the first person on the waiting list
 */
function _booking_get_waitinglist_top()
{
	global $event;
	
	$result = db_query('SELECT p.nid, p.booking_firstname, p.booking_lastname, pay.booking_payment_date
	                    FROM {booking_person} p, {booking_payment} pay
					    WHERE booking_status = 2 and booking_event_id = :eid and p.nid = pay.booking_person_nid
	                    ORDER BY pay.booking_payment_date
						LIMIT 1',
						array(':eid' => $event->eid));		
	
	foreach ($result as $person)
	{
		watchdog('booking', "First person on the waiting list: @info", array('@info' => var_export($person, TRUE)));
		return $person->nid;
	}
	//in case there was no one on the waiting list
	return -1;
}

/**
 * Helper function to update the status of a registration
 */
function _booking_change_status($nid, $status_id)
{
	db_update('booking_person')
	  ->fields(array(
		'booking_status' => $status_id,
		))
	  ->condition('nid', $nid)
	  ->execute();	
}

function _datearray_to_ts($date)
{
	date_default_timezone_set(TIMEZONE); 
	$tz = new DateTimeZone(TIMEZONE); 
	
	if (empty($date) || ($date['month'] == '' && $date['day'] == '' && $date['year'] == ''))
		return 0;
	else
		watchdog('booking', "Date array to timestamp: @info", array('@info' => var_export($date, TRUE)));

	$gmt_ts = mktime(0, 0, 0, $date['month'], $date['day'], $date['year']);
	$ts = new DateTime("@$gmt_ts");
	$ts->setTimezone($tz);	
	
	return $ts->format("U");
}

function _datetime_array_to_ts($date)
{
	//watchdog('booking', 'Date-time Conversion: @info', array('@info' => var_export($date, TRUE)));
	date_default_timezone_set(TIMEZONE); 
	$tz = new DateTimeZone(TIMEZONE); 
	
	if (empty($date) || ($date['month'] == '' && $date['day'] == '' && $date['year'] == ''))
		return 0;
	else
		watchdog('booking', "Date array to timestamp: @info", array('@info' => var_export($date, TRUE)));	

	$gmt_ts = mktime($date['hour'], $date['minute'], 0, $date['month'], $date['day'], $date['year']);
	$ts = new DateTime("@$gmt_ts");
	$ts->setTimezone($tz);	
	
	return $ts->format("U");
}

 
function _date_to_ts($date) {
	$date_split = _booking_split_date($date);

	date_default_timezone_set(TIMEZONE); 
	$tz = new DateTimeZone(TIMEZONE); 

	if ($date_split[0] == '-1' )
		return 0;
	else
	{
		$gmt_ts = mktime(0, 0, 0, $date_split[2], $date_split[3], $date_split[1]);
		$ts = new DateTime("@$gmt_ts");
		$ts->setTimezone($tz);	

		return $ts->format("U");		
	}
    //return mktime($date_split[5], $date_split[6], 0, $date_split[2], $date_split[3], $date_split[1]);
}

function _datetime_to_ts($date) {
	$date_split = _booking_split_date($date);

	date_default_timezone_set(TIMEZONE); 
	$tz = new DateTimeZone(TIMEZONE); 

	if ($date_split[0] == '-1' )
		return 0;
	else
	{
		$gmt_ts = mktime($date_split[5], $date_split[6], 0, $date_split[2], $date_split[3], $date_split[1]);
		$ts = new DateTime("@$gmt_ts");
		$ts->setTimezone($tz);	

		return $ts->format("U");		
	}
    //return mktime($date_split[5], $date_split[6], 0, $date_split[2], $date_split[3], $date_split[1]);
}

/**
 * Function to split date into array
 *
 * @param $date in format YYYY-MM-DD
 * @return array containing Year, Month, Day
 */
function _booking_split_date($date) {
  $pattern = '/^(\d{4})-(\d{2})-(\d{2})(\s(\d{2})\:(\d{2}))?/';
  if (preg_match($pattern, $date, $matches)) {
    return $matches;
  } else {
    return array('-1');
  }
}

/**
 * Function to re-arrange date
 *
 * @param $date in format YYYY-MM-DD
 * @return array containing Year, Month, Day
 */
function _arrange_date($date) {
  $pattern = '/^(\d{4})-(\d{2})-(\d{2})/';
  if (preg_match($pattern, $date, $matches)) {
    return $matches;
  } else {
    return array('-1');
  }
}

/**
 * Helper function to ensure timestamp is converted to correct local time
 */
function _booking_convert_ts($timestamp)
{
	//load the timestamp
	date_default_timezone_set(TIMEZONE); 
	$tz = new DateTimeZone(TIMEZONE); 

	$date = new DateTime("@$timestamp");
	$date->setTimezone($tz);
	
	return $date;	
}


/**
 * Helper function to calculate the timestamp corresponding with the DOB requirements
 */
function _booking_max_dob_ts()
{
  //calculate DOB limit as defined by configuration
  $max_dob_matches = _booking_split_date(variable_get('booking_max_dob','0')); 
  return mktime(12, 0, 0, $max_dob_matches[2], $max_dob_matches[3], $max_dob_matches[1]);	
}

/**
 * Helper function to calculate the average age in days, months and years at the start of the event
 */
function _booking_avg_age($sum, $count, $reference_ts)
{
	global $event;
	//calculate the average age timestamp
	$average = $sum / $count;
	//get the difference between now and the average timestamp
	$average_date = _booking_convert_ts(floor($average));
	$now_date = _booking_convert_ts(floor($reference_ts));
	$difference = $average_date->diff($now_date);
	//convert the difference into english
	return $difference->y . " years, " . $difference->m . " months, " . $difference->d . " days";
}

/**
 * Helper function to calculate persons age in years at start of event
 */
function _booking_get_age_years($dob_ts)
{
	global $event;
	$reference_ts = _booking_convert_ts($event->booking_event_start);
	$dob = _booking_convert_ts($dob_ts);
	return $dob->diff($reference_ts)->y;		
}

function _date_range_to_string($date_start, $date_end) {
  $start = _booking_split_date($date_start);
  $end = _booking_split_date($date_end);
  $final_string = '';
  
  //check for correctly formatted dates
  if ($start[0] == '-1' || $end[0] == '-1') {
    //incorrect response
    form_set_error('yc_date_endbeforestart', t('Invalid date format received from !date or !date_end.', array('!date' => $date_start, '!date_end' => $date_end)));
  }	else {
    //start with the day field
    //mktime uses format month, day, year
	  $end_string = strftime("%e", mktime(12, 0, 0, $end[2], $end[3], $end[1]));
	  $start_string = strftime("%e",  mktime(12, 0, 0, $start[2], $start[3], $start[1]));  
    
    //now include the month in the comparison. Compare including the year.
    if (mktime(12, 0, 0, $end[2], 1, $end[1]) > mktime(12, 0, 0, $start[2], 1, $start[1])) {
      //use the textual version to make things more readable
      //strftime  (  string $format  [,  int $timestamp = time()  ] )
      //%B  	Full month name, based on the locale
      $end_string .= ' ' . strftime("%B", mktime(12, 0, 0, $end[2], 1, $end[1]));
      $start_string .= ' ' . strftime("%B",  mktime(12, 0, 0, $start[2], 1, $start[1]));
    } else {
      $end_string .= ' ' . strftime("%B", mktime(12, 0, 0, $end[2], 1, $end[1]));
      //no need to append anything to $start_string
    }		  

    //create a timestamp based on 1 Jan that year to compare
    if (mktime(12, 0, 0, 1, 1, $end[1]) > mktime(12, 0, 0, 1, 1, $start[1])) {
      //create two seperate strings, one to hold the last part of the date range
      //the other to hold the first part
      $end_string .= ' ' . $end[1];
      $start_string .= ' ' . $start[1];
    } else {
      $end_string .= ' ' . $end[1];
      //no need to append anything to $start_string
    }
    
    //put both parts together
    $final_string = $start_string . ' to ' . $end_string;
  }	
	return $final_string;
}

/**
 * Function to correctly clone an associative array storing objects
 * Taken from http://stackoverflow.com/questions/1532618/is-there-a-function-to-make-a-copy-of-a-php-array-to-another
 */
function _booking_clone_array($copied_array) {
    return array_map(function($element) {
        return (
            ((is_array($element))
                ? call_user_func(__FUNCTION__, $element)
                : ((is_object($element))
                    ? clone $element
                    : $element
                )
            )
        );
    }, $copied_array);
}


/**
 * Function to randomise the ordering of an array
 * taken from http://stackoverflow.com/questions/4102777/php-random-shuffle-array-maintaining-key-value
 */
function _booking_shuffle_assoc($list) { 
  if (!is_array($list)) return $list; 

  $keys = array_keys($list); 
  shuffle($keys); 
  $random = array(); 
  foreach ($keys as $key) { 
    $random[$key] = $list[$key]; 
  }
  return $random; 
}

/**
 * Helper function to cycle through a list without getting in an endless loop
 * Used for calculating study groups and maybe readings groups
 *
 * Each iteration through the list the maximum permitted size for a given entry will be increased by one
 * until we find an available entry or we run out of cycle counts
 */
function _booking_loop_carefully(&$list, $field, &$i, $maximum, $list_size, $max_cycle_count, &$log_array)
{
	$cycle = 0;
	while ($list[$i][$field] >= $maximum)
	{
		$log_array[] = t("Field !field is !value for entry !index, which larger than maximum allowed size, !max. Moving to next entry in list.", 
			array('!field' => $field, '!value' => $list[$i][$field], '!max' => $maximum, '!index' => $i));

		$i++;
		//reset the counter if we go past the end
		if ($i > $list_size)
		{
			$i = 1;	
			//make sure we don't get stuck in an infinite loop - only go past the end once
			if ($cycle >= $max_cycle_count)
			{
				$log_array[] = t("Reached the end of !field list. Unable to find satisfactory entry after !num cycles.", 
									array('!field' => $field, '!num' => $cycle));
				return;
			} 
			elseif ($cycle > 0)
			{
				//temporarily increase the maximum size of our groups by one
				$maximum++;					
			}
			//always increment the cycle counter if we've reached the end
			$cycle++;;
		}			
	}	
}

/**
 * Function to mark an attendee as processed for group calculations
 * @param $input string containing passport number to be verified
 */
function _booking_assign_attendee_group($nid, $session_id, $gender, $age, &$attendee_list, &$session_count, &$log_array)
{
	$previous_session = 0;
	
	//check for valid attendee
	if (empty($nid))
	{
		drupal_set_message(t('Attempting to process a non-existent node id.'));
		return;
	}
	
	//check if this person had already been processsed
	if ($attendee_list[$nid]->processed == 1 && $attendee_list[$nid]->session > 0)
	{
		$log_array[] = t('Detected re-assignment of id !id previously assigned to session !session.', 
			array('!id' => $nid, '!session' => $attendee_list[$nid]->session)
		);	
		
		$previous_session = $attendee_list[$nid]->session;
		
		//update previous session totals
		$session_count[$previous_session][$gender]--;
		$session_count[$previous_session]['total']--;
		if ($age < 20)
			$session_count[$previous_session]['under20']--;
		elseif($age >= 20 && $age < 25)
			$session_count[$previous_session]['20to25']--;
		else
			$session_count[$previous_session]['over25']--;				
	}
	
	//mark this person as processed in the working list
	$attendee_list[$nid]->processed = 1;
	$attendee_list[$nid]->session = $session_id;
		
	//record the category of person
	$session_count[$session_id][$gender]++;
	$session_count[$session_id]['total']++;
	
	//process ages
	if ($age < 20)
		$session_count[$session_id]['under20']++;
	elseif($age >= 20 && $age < 25)
		$session_count[$session_id]['20to25']++;
	else
		$session_count[$session_id]['over25']++;	
}


/**
 * Function for cleaning up room allocations for people that have withdrawn their registration
 * @param $nid - the node id for the person
 * @return nothing
 */
function _booking_rooms_cleanup($nid)
{
	global $event;
	
	//first of all make sure we need to do anything
	if (variable_get('booking_enable_roomallocations', 0) == 1)
	{
		//should only be one room allocation per person, so no need to loop over the results
		$room_mapping = db_query("SELECT * FROM {booking_room_mapping} WHERE booking_eventid = :eid AND booking_nodeid = :nid",
			array(':eid' => $event->eid, ':nid' => $nid))
			->fetchObject();

		if ($room_mapping)
		{						
			$message = t("Removing id !nid from room id !room.", 
				array('!nid' => $nid, '!room' => $room_mapping->booking_roomid)
			);
			watchdog('booking', $message);
			drupal_set_message($message, 'status', FALSE);
			
			db_delete('booking_room_mapping')
				->condition('booking_eventid', $event->eid)
				->condition('booking_nodeid', $nid)
			 	->execute();	
				
									
		}	//for each room
	}		//end check for room allocations enabled
}			//end function

/**
 * Function for cleaning up study groups for people that have withdrawn their registration
 * @param $nid - the node id for the person who has withdrawn their registration
 * @return nothing
 */
function _booking_studygroups_cleanup($nid)
{
	global $event;
	
	
	//first of all make sure we need to do anything
	if (variable_get('booking_enable_studygroups', 0) == 1)
	{
		//query for any groups this person is assigned to
		$to_remove_query = db_query("SELECT m.* FROM {booking_studygroup_mapping} m WHERE booking_node_id = :nid", 
			array(':nid' => $nid));
		$to_remove = $to_remove_query->fetchAll();

		foreach ($to_remove as $group)
		{					
			$message = t("Removing id !nid from group id !group, session !session with role !role", 
				array('!nid' => $nid, '!group' => $group->booking_studygroup_id, '!session' => $group->booking_session_id,
				'!role' => _booking_studygroup_role_lookup($group->booking_studygroup_role)
				)
			);
			watchdog('booking', $message);
			drupal_set_message($message, 'status', FALSE);
			
			db_delete('booking_studygroup_mapping')
				->condition('booking_eventid', $event->eid)
				->condition('booking_node_id', $nid)
				->condition('booking_studygroup_id', $group->booking_studygroup_id)
			 	->execute();			
		}	//for each group
	}		//end check for study groups enabled
}			//end function

/**
 * Function for calculating statistics of attendees
 */
function _booking_generate_statistics($booking_list)
{
	global $event;

	$statistics = array(
		'males' => 0,
		'females' => 0,
		'under20' => 0,
		'20to25' => 0,
		'over25' => 0,
	);
	
	foreach ($booking_list as $person)
	{
		//ignore people that havent paid or are no longer coming or missed the payment deadline
		if ($person->booking_status == 0 || $person->booking_status == 3 || $person->booking_status == 4)
			continue;
		
		if ($person->booking_gender == 'M')
			$statistics['males']++;
		else
			$statistics['females']++;

		$age = _booking_get_age_years($person->booking_dob);

		if ($age < 20)
			$statistics['under20']++;
		elseif($age >= 20 && $age < 25)
			$statistics['20to25']++;
		else
			$statistics['over25']++;
	}
	
	return $statistics;
}

//figure out if we're in the right time period for discounted registration rates
function _booking_is_earlybird()
{
	global $event;

	//figure out if we're in the earlybird rate section
	//$early = db_query("SELECT booking_earlybird_close FROM {booking_event} where eid = :eid", array(
	//				':eid' => $event->eid))
	//		->fetchObject();  
	if ($event->booking_earlybird_close > time())
		return TRUE;
	else
	{
		return FALSE;
	}	
}

function _booking_datepaid_ts($nid)
{
	$query = db_query("SELECT * FROM {booking_payment} where booking_person_nid = :nid", array(':nid' => $nid))
			->fetchObject();
		
	if ($query)				
		return $query->booking_payment_date;
	else
		return 0;
}

/**
 * Helper function to return the amount for a booking deposit, if there is one
 */
function _booking_deposit_amount($include_fees = TRUE)
{
	global $event;
	
	$deposit = db_query("SELECT price.booking_price, price.booking_price_descrip " .
						"FROM {booking_price} price WHERE booking_eventid = :eventid and booking_depositonly = 1 and booking_price_active = 1",
						array(':eventid' => $event->eid))
			->fetchObject();	
			
	if ($deposit)
	{
		//if we're using paypal, add the transaction fee
		if (variable_get('booking_use_paypal', 0) == 1 && $include_fees == TRUE)
		{
			//add the 30 cent fixed cost
			$amount_owing = $deposit->booking_price + 0.3;
			//and the 2.4 percent transaction fee
			$amount_owing = $amount_owing / (1 - 0.024);
		}
		else
		{
			$amount_owing = $deposit->booking_price;		
		}
		//return the calculated amount rounded to two decimal places
		return number_format($amount_owing, 2, '.', '');
	}
	else
	{
		//there is no deposit amount
		return 0;
	}
}

/**
 * Calculate exactly how much a person has already paid
 */
function _booking_amount_paid($nid, $person = NULL)
{
	$amount_paid = 0;
	
	//fetch details about the person if we don't already have them
	if ($person == NULL)
	{
	    $person = db_query("SELECT price.booking_price, price.booking_late_price, person.booking_payment_id, " .
					"person.booking_total_pay_reqd, person.booking_amount_paid, person.booking_partner_id " .
					"FROM     {booking_person} person, {booking_price} price " .
					"WHERE person.nid = :nid " .
					"AND person.booking_payment_id = price.pid", 
					array(':nid' => $nid))
					->fetchObject();	
	}	

	//check for a spouse
	if ($person->booking_partner_id > 0)
	{
		//watchdog('booking', "Checking total paid for married person");
		
		//look for payments in the payment transaction table
		
		//if we're combining the payment for married couples
		if (variable_get('booking_enable_combined_pricing', 0) == 1)
		{
			//check for payments in the paypal transaction table from either spouse
			$query = db_query("SELECT booking_mc_gross, booking_mc_fee FROM booking_payment " .
					"WHERE booking_person_nid = :nid OR booking_person_nid = :spousenid",
					array(':nid' => $nid, 'spousenid' => $person->booking_partner_id));
		} 
		else {
			//check for payments in the paypal transaction table from just this person
			$query = db_query("SELECT booking_mc_gross, booking_mc_fee FROM booking_payment " .
					"WHERE booking_person_nid = :nid",
					array(':nid' => $nid));		
		}	

		//add up all the payments	
		foreach ($query as $payment)
			$amount_paid += ($payment->booking_mc_gross - $payment->booking_mc_fee);

		//watchdog('booking', "Total amount paid according to paypal payments table is " . $amount_paid);	

		//there were no payment transactions, so rely on what the amount is set to in the individual registration records
		if ($amount_paid == 0)
		{
            //if we're combining the payment for married couples
			if (variable_get('booking_enable_combined_pricing', 0) == 1)
			{
				$spouse = db_query("SELECT person.booking_amount_paid  " .
							"FROM     {booking_person} person " .
							"WHERE person.nid = :nid ", 
							array(':nid' => $person->booking_partner_id))
							->fetchObject();				
            	$amount_paid = $person->booking_amount_paid + $spouse->booking_amount_paid;
				//watchdog('booking', "Total combined payments for couple based on totals in booking_person table is " . $amount_paid);
			}
			else
			{
            	$amount_paid = $person->booking_amount_paid;
				//watchdog('booking', "Total amount paid for individual based on totals in booking_person table is " . $amount_paid);
			}
			//end combined payments check
		}
	}
	//no spouse found
	else
	{		
		//Check if there are payment records in the paypal transaction table for this unmarried person 
		//if so, base their payments on the gross amount in there rather than what the person booking_person database says	
		$query = db_query("SELECT booking_mc_gross, booking_mc_fee FROM booking_payment " .
				"WHERE booking_person_nid = :nid",
				array(':nid' => $nid));						
		foreach ($query as $payment)
			$amount_paid += ($payment->booking_mc_gross - $payment->booking_mc_fee);

		//watchdog('booking', "Total amount paid according to paypal payments table is " . $amount_paid);	

		//if there were no results, $amount_paid will still be 0
		if ($amount_paid == 0)
			$amount_paid = $person->booking_amount_paid;
		//in case there has been some manual adjustment
		//elseif ($amount_paid < $person->booking_amount_paid)
		//	$amount_paid = $person->booking_amount_paid;
	}

	//watchdog('booking', "Total amount already paid for this registration " . $nid . " is " . $amount_paid);	
				
	return $amount_paid;
}

/**
 * Function to calculate the total amount a person is required to pay
 *
 * @param $person - the populated node object representing this person including related price information
 * @return amount owing as a decimal value
 */
function _booking_total_due($person)
{
	$total_due = 0.00;
	
	//check for a spouse
	if ($person->booking_partner_id > 0 && variable_get('booking_enable_combined_pricing', 0) == 1)
	{
		//watchdog('booking', "Calculating total amount due for a married couple.");
		
		//TODO: figure out if anything special is needed here
	}
	
	//determine what rate this person needs to pay
	if ($person->booking_welfare_required == 'Y' || $person->booking_committee_member == 'Y')
	{
		//cater for any manual adjustment
		//watchdog('booking', "This registration is eligible for welfare rates");
		$total_due = $person->booking_total_pay_reqd;
	}
	//the early bird rate will be defined by default for the registration	
	elseif (_booking_is_earlybird() == TRUE)
	{
		$total_due = $person->booking_total_pay_reqd;
	}
	//finally we must be in the late-fee period
	else
	{
		$total_due = $person->booking_late_price;
	}

	return $total_due;
}


/**
 * Function to calculate the amount outstanding for a person/married couple
 *
 * @param $person - the object relating to the registration node
 * @param $amount_paid - if we have previously calculated the amount paid, this can be passed as a value
 * @param $include_paypal_fees - boolean to indicate whether we want the net amount or the amount owing including paypal fees
 * @return amount owing as a decimal value
 */
function _booking_amount_owing($person, $amount_paid = 0, $include_paypal_fees = TRUE)
{
	//$amount_paid = 0;
	//$total_due = 0;
	
	//fetch details about the person
	/*
    $person = db_query("SELECT price.booking_price, price.booking_late_price, person.booking_payment_id, " .
				"person.booking_total_pay_reqd, person.booking_amount_paid, person.booking_partner_id, person.booking_country, person.booking_welfare_required, person.booking_committee_member " .
				"FROM     {booking_person} person, {booking_price} price " .
				"WHERE person.nid = :nid " .
				"AND person.booking_payment_id = price.pid", 
				array(':nid' => $nid))
				->fetchObject();	
	
	//$person = node_load($nid);
	*/
	//quick sanity check
	if (! $person->nid) {
		watchdog('booking', "Unable to find matching person relating to registration id. Details were '" . var_export($person, TRUE) . "' .");	
		return 0.00;
	}			

	$total_due = _booking_total_due($person);

	//if we didn't get the amount paid as a command line parameter, check it now
	if ($amount_paid == 0)
	{
		$amount_paid = _booking_amount_paid($person->nid, $person);		
	}
	
	//check if there is anything outstanding
	//use the original total amount required rather than the late-rate, to cater for people that paid before the late rate
	if ($amount_paid >= $person->booking_total_pay_reqd)
	{
		//watchdog('booking', "This person doesn't owe any money: @info", array('@info' => var_export($person, TRUE)));
		return 0;
	}
	
	//if we're using paypal, add the transaction fee
	if (variable_get('booking_use_paypal', 0) == 1 && $include_paypal_fees == TRUE)
	{
		//add the 30 cent fixed cost
		$amount_owing = $total_due - $amount_paid + 0.3;
		//and the 2.4 percent transaction fee
		if ($person->booking_country === "Australia")
			$amount_owing = $amount_owing / (1 - 0.024);
		//paypal charges 3.4 percent if they're doing a currency conversion
		//assume that everyone not based in Australia will be doing a currency conversion
		else
		{
			$amount_owing = $amount_owing / (1 - 0.034);
			//watchdog('booking', "This is an international registration.");
		}
	}
	else
		$amount_owing = $total_due - $amount_paid;
	return number_format($amount_owing, 2, '.', '');
}

/**
 * Function to process the amount to refund a person when they withdraw their registration
 *
 * @param $person - the populated node object representing this person including related price information
 * @return amount to be refunded for this registration
 */
function _booking_process_refund($person)
{
	global $event;
	$refund = 0;
	
	//calculate amount to be refunded
	$paid = _booking_amount_paid($person->nid, $person);
	if ($paid > 0) 
	{
		//calculate the refund due
		//don't include paypal fees in the deposit amount
		$refund = $paid - _booking_deposit_amount(FALSE);
		
		//if there is a spouse, subtract their deposit too
		if (variable_get('booking_enable_combined_pricing', 0) == 1 && $person->booking_partner_id > 0)
		{
			$refund = $refund - _booking_deposit_amount(FALSE);
		}
		
	} 
	
	watchdog('booking', "Processing refund due to !first !last. Calculated as $!refund", 
			array('!first' => $person->booking_firstname, '!last' => $person->booking_lastname, '!refund' => $refund));		

	//$refund_due = $person->booking_amount_paid - $refund;
	if ($refund == 0)
	{
		//mark the refund as processed since no action is required and don't add an entry into the manual payments table
		db_update('booking_person')
		  ->fields(array(
			'booking_refund_due' => 0,
			'booking_refund_processed' => 'Y',
			))
		  ->condition('nid', $person->nid)
		  ->execute();		
	}
	else
	{
		//update booking_amount_paid
		db_update('booking_person')
		  ->fields(array(
			'booking_refund_due' => $refund,
			))
		  ->condition('nid', $person->nid)
		  ->execute();	
		
		//add manual payment entry for refund
		$result = db_insert('booking_payment')
		  ->fields(array(
			'booking_person_nid' => $person->nid,
			'booking_eventid' => $event->eid,
	 		'booking_mc_gross' => $refund * -1,
	 		'booking_mc_currency' => 'AUD',
	 		'booking_mc_fee' => '0.00',
	 		'booking_quantity' => 1,
	 		'booking_invoice' => 'Refund',
			'booking_payer_id' => '',
	 		'booking_payment_date' => REQUEST_TIME,
	 		'booking_payment_status' => '',
	 		'booking_first_name' => $person->booking_firstname,
	 		'booking_last_name' => $person->booking_lastname,
	 		'booking_buyer_email' => '',
	 		'booking_payer_status' => '',
	 		'booking_item_name' => 'Refund',
	 		'booking_ipn_track_id' => '',
		  ))
		  ->execute();		
	}

	//return the amount to refund this person
	return $refund;
}


/**
 * Helper function to generate paypal form for payments
 */
function _booking_paypal_form($person, $invoiceid, $amount_owing, $button_text) {
	return drupal_render(drupal_get_form('_booking_paypal_form_builder', $person, $invoiceid, $amount_owing, $button_text));
}

/**
 * Helper function to generate form elements for paypal form
 */
function _booking_paypal_form_builder($node, &$form_state, $person, $invoiceid, $amount_owing, $button_text) {
	global $event;
	
	//get our current path so we can send the user back here if they cancel
	$path = isset($_GET['q']) ? $_GET['q'] : '<front>';

	//paypal specific settings
	$vars = array(
		'module' => 'Booking System',
		'type' => $event->booking_eventname,
		//'custom' => $data,
		'item_name' => $event->booking_eventname . ' ' . $person->booking_price_descrip,
		'invoice' => $invoiceid,
		'no_shipping' => TRUE,
		'no_note' => TRUE,
		'currency_code' => 'AUD',
		'return' => url('bookingfinal', array('absolute' => TRUE)),
		'cancel_return' => url($path, array('absolute' => TRUE)),
		'rm' => '2',
		'amount' => $amount_owing,
		'last_name' => $person->booking_lastname,
		'first_name' => $person->booking_firstname,
		'cmd' => '_xclick',
		'notify_url' => url(BOOKING_PAYPAL_IPN_PATH, array('absolute' => TRUE)),
		'business' => variable_get('booking_paypal_account', '')
	);	

	$form['#action'] = url(variable_get('booking_paypal_sandbox', 0) ? BOOKING_PAYPAL_SUBMIT_URL_SANDBOX : BOOKING_PAYPAL_SUBMIT_URL, array('absolute' => TRUE));

	//turn the array into a form
	foreach($vars as $name => $value) {
		$form[$name] = array(
			'#type'  => 'hidden',
			'#value' => $value,
		);
	}	

	$form['submit'] = array(
		'#type' => 'button',
		'#value' => t($button_text),
	);	

	//watchdog('booking', 'Booking Balance payment: @info', array ('@info' => var_export($form, TRUE)));	
	return $form;
}

/**
 * Helper function to format registrations details for summary in the confirmation email
 */
function _booking_details_email_summary($node) {

	//query for payment type description
	$payment_description_query = db_select('booking_price', 'p')
		->condition('p.pid', $node->booking_payment_id,'=')
		->fields('p', array('booking_price_descrip'))
		->execute()
		->fetchObject();
		
	//watchdog('booking', "Payment description: @info", array('@info' => var_export($payment_description_query, TRUE)));		
  
	$rows = array();
	$rows[] = t('Registration Reference Number:  !id', array('!id' => $node->nid));
	$rows[] = t('Date/Time registered:  !timestamp', array('!timestamp' => _booking_convert_ts($node->booking_timestamp)->format('j F, Y H:i')));	
	$rows[] = t('Name:  !first !last', array('!first' => $node->booking_firstname, '!last' => $node->booking_lastname));
	$rows[] = t('Gender:  !gender', array('!gender' => $node->booking_gender == 'M' ? 'Male' : 'Female'));
	$rows[] = t('Date of birth:  !dob', array('!dob' => _booking_convert_ts($node->booking_dob)->format('d/m/Y')));	
	
	if (variable_get('booking_enable_passport', 1) == 1)
	{
		$rows[] = t('Passport Number:  !value', array('!value' => $node->booking_passport_num));	
		$rows[] = t('Passport Expiry:  !timestamp', array('!timestamp' => _booking_convert_ts($node->booking_passport_expiry_date)->format('d/m/Y')));	
		$rows[] = t('Passport Exact Issued Name:  !value', array('!value' => $node->booking_passport_issue_name));	
		$rows[] = t('Passport Issue Location:  !value', array('!value' => $node->booking_passport_issue_location));							
	}
	
	$rows[] = t('Email address:  !email', array('!email' => $node->booking_email));
	$rows[] = t('Home Phone Number:  !home', array('!home' => $node->booking_phone));
	$rows[] = t('Mobile Phone Number:  !mob', array('!mob' => $node->booking_mobile));
	$rows[] = t("Postal Address:\n!street\n!suburb !state !code\n!country", 
	                                        array('!street' => $node->booking_street, '!suburb' => $node->booking_suburb,
	                                              '!state' => $node->booking_state, '!code' => $node->booking_postcode,
	                                              '!country' => $node->booking_country));
	$rows[] = t('Ecclesia:  !ecclesia', array('!ecclesia' => $node->booking_ecclesia));
	$rows[] = t('Baptised:  !ans', array('!ans' => ($node->booking_baptised == 'Y' ? 'Yes' : 'No')));
	$rows[] = t('Married:  !ans', array('!ans' => ($node->booking_married == 'Y' ? 'Yes' : 'No')));
	$rows[] = t("If married, attending partner's name:  !name", array('!name' => $node->booking_partner_name));
	
	if (variable_get('booking_enable_tshirts', 1) == 1)
		$rows[] = t('Hoodie Size: !size', array('!size' => $node->booking_shirt_size));
		
	$rows[] = t('Emergency Contact Name: !contact', array('!contact' => $node->booking_guardian_name));
	$rows[] = t('Emergency Contact Relationship: !relationship', array('!relationship' => $node->booking_guardian_type));
	$rows[] = t('Emergency Contact Phone: !phone', array('!phone' => $node->booking_guardian_phone));
	$rows[] = t('Emergency Contact Alternate Phone: !phone', array('!phone' => $node->booking_guardian_phone_alt));  
	if (variable_get('booking_enable_medicare', 1) == 1)
		$rows[] = t('Medicare Number: !medicare', array('!medicare' => $node->booking_medicare));    
	
	if (variable_get('booking_enable_roommate', 0) == 1)
	{
		$rows[] = t('Preferred room-mates:  !room', array('!room' => $node->booking_room_mate1 . ' ' . $node->booking_room_mate2));
	}

	if (variable_get('booking_enable_helpareas', 1) == 1)
	{
		$help_areas = '';
		if ($node->booking_help_music)
		  $help_areas .= 'music: ' . $node->booking_help_music . ', ';
		if ($node->booking_help_reading == 'Y')
		  $help_areas .= 'reading, ';
		if ($node->booking_help_chairing == 'Y')
		  $help_areas .= 'chairing, '; 
		if ($node->booking_help_readgroup_lead == 'Y')
		  $help_areas .= 'reading group leading, ';
		if ($node->booking_help_discussgroup_lead == 'Y')
		  $help_areas .= 'discussion group leading, ';     
		if ($node->booking_help_praying == 'Y')
		  $help_areas .= 'praying, ';  
		if ($node->booking_help_meditations == 'Y')
		  $help_areas .= 'meditations, ';  

		$rows[] = t('Help areas:  !help', array('!help' => $help_areas)); 
	}

	if (variable_get('booking_enable_skills', 1) == 1)
	{
		$skill_areas = '';
		if ($node->booking_skills_builder == 'Y')
		  $skill_areas .= 'builder, ';
		if ($node->booking_skills_cooking == 'Y')
		  $skill_areas .= 'cook, '; 
		if ($node->booking_skills_childminding == 'Y')
		  $skill_areas .= 'child minding, ';
		if ($node->booking_skills_language == 'Y')
		  $skill_areas .= 'speaks languages: ' . $node->booking_skills_language_details . ', ';     
		if ($node->booking_skills_other == 'Y')
		  $skill_areas .= 'other skills: ' . $node->booking_skills_other_details . ', ';     
		$rows[] = t('Mission related skills: !value', array('!value' => $skill_areas));
		$rows[] = t('Previous Mission Experience: !value', array('!value' => $node->booking_mission_experience_details));  		
	}	
	$rows[] = t('Special Dietary Requirements: !dietary', array('!dietary' => $node->booking_dietary));
	$rows[] = t('Special Medical Conditions: !medical', array('!medical' => $node->booking_medical_conditions));
	$rows[] = t('Gross Amount Paid:  !payment', array('!payment' => $node->booking_amount_paid));
	$rows[] = t('Net Amount Due:  !payment', array('!payment' => $node->booking_total_pay_reqd));
	$rows[] = t('Payment Type:  !payment', array('!payment' => $payment_description_query->booking_price_descrip));
	
	foreach ($rows as $key => $value)
	  $rows[$key] = wordwrap($value);
	return implode("\n", $rows);
}

/**
 * Helper function to format travel form summary
 */
function _booking_travelform_email_summary($node) {
	$output = '';

	//look up the actual name if a boyfriend/girlfriend is defined
	if ($node->booking_bf_gf_nid != 0)
	{
		$query = db_query("Select booking_firstname, booking_lastname from {booking_person} where nid = :nid",
					array(':nid' => $node->booking_bf_gf_nid))
					->fetchObject();	
		$bf_gf = $query->booking_firstname . " " . $query->booking_lastname;	
	}
	else
		$bf_gf = "N/A";			

	$rows = array();

	$rows[] = t('Name:  !first !last', array('!first' => $node->booking_firstname, '!last' => $node->booking_lastname));
	$rows[] = t('Transport Type: !transport', array('!transport' => $node->booking_transport_type));
	
	if ($node->booking_transport_type == 'Flying')
	{
		$rows[] = t('Catching the train to Study Week: !value', array('!value' => $node->booking_transport_from_morriset_reqd == 1 ? 'Yes' : 'No'));
		$rows[] = t('Inbound Flight Number: ' . $node->booking_flightnum_inbound);
		$rows[] = t('Flight Arrival: !date', array('!date' => format_date($node->booking_flight_datetime_inbound, 'custom', 'd/m/Y H:i')));
		$rows[] = t('Outbound Flight Number: ' . $node->booking_flightnum_outbound);
		$rows[] = t('Flight Departure: !date', array('!date' => format_date($node->booking_flight_datetime_outbound, 'custom', 'd/m/Y H:i')));
	}
	$rows[] = t('Accommodation before Study Week Required: !value', array('!value' => $node->booking_accom_before_reqd == 1 ? 'Yes' : 'No'));
	$rows[] = t('Accommodation after Study Week Required: !value', array('!value' => $node->booking_accom_after_reqd == 1 ? 'Yes' : 'No'));
	//fields from booking_person
	if (variable_get('booking_enable_dietary', 0) == 1)
		$rows[] = t('Special Dietary Requirements: ' . $node->booking_dietary);
	if (variable_get('booking_enable_roommate', 0) == 1)
		$rows[] = t('Special Medical Conditions: ' . $node->booking_medical_conditions);  
	$rows[] = t('Boyfriend/Girlfriend: ' . $bf_gf);
	$rows[] = t('Requested room mate(s): ' . $node->booking_room_mate1);
	

	foreach ($rows as $key => $value)
	  $rows[$key] = wordwrap($value);

	return implode("\n", $rows);
}

/**
 * Helper function to format summary of studygroup sessions to be used as a token
 */
function _booking_studygroup_email_summary($node) {
	global $event;
	$rows = array();

	//display study session data if enabled
	if (variable_get('booking_enable_studygroups', 0) == 1)
	{	
		//look up the titles of the study groups
		$studygroups_query = db_query("SELECT * FROM {booking_studygroup_list} WHERE booking_eventid = :eid", 
			array(':eid' => $event->eid));
		$studygroups = $studygroups_query->fetchAllAssoc('sid');		
	
		for ($i = 1; $i <= variable_get('booking_studygroup_count','0'); $i++)
		{
			//calculate the session references
			$sessionid = "session" . $i;
			$roleid = $sessionid . "_role";	
			
			//check that this study group session has been defined for this attendee
			if (!empty($node->$sessionid))
			{
				$rows[] = t($studygroups[$i]->booking_studygroup_descrip . ": Group " . $node->$sessionid . ", " . _booking_studygroup_role_lookup($node->$roleid));				
			}				
		}
	}

	foreach ($rows as $key => $value)
	  $rows[$key] = wordwrap($value);

	return implode("\n", $rows);
}

/**
 * Helper function to format information matching leaders and helpers, to be used as a token
 */
function _booking_leader_helper_email_summary($node) {
	global $event;
	$rows = array();
	$found = FALSE;

	//display study session data if enabled
	if (variable_get('booking_enable_studygroups', 0) == 1)
	{	
		//look up the titles of the study groups
		$studygroups_query = db_query("SELECT * FROM {booking_studygroup_list} WHERE booking_eventid = :eid", 
			array(':eid' => $event->eid));
		$studygroups = $studygroups_query->fetchAllAssoc('sid');		
	
		for ($i = 1; $i <= variable_get('booking_studygroup_count','0'); $i++)
		{
			//don't print info about the readings groups
			if ($i == variable_get('booking_readinggroup_id','7'))
				continue;

			//calculate the session references
			$sessionid = "session" . $i;
			$roleid = $sessionid . "_role";	
			$otherperson_name = "TBA";
			
			//check that this study group session has been defined for this attendee and that they 
			if (!empty($node->$sessionid) && $node->$roleid > 0)
			{
				//make sure we only add this prefix text once, as soon as we've found a matching role
				if ($found == FALSE)
				{
					$found = TRUE;
					$rows[] = t("You have been assigned to perform the following roles for study groups:");
				}
				
				//TODO: use a function for this.
				//if they're a leader or reserver leader, then the matching person is the helper	
				if ($node->$roleid == 1 || $node->$roleid == 3)
				{
					$role = "Leader";
					$otherrole = "Helper";
					$otherrole_id = 2;
				}
				//otherwise the matching person is the leader
				else
				{
					$role = "Helper";
					$otherrole = "Leader";
					$otherrole_id = 1;
				}

				//find the other person
				$otherperson_query = db_query("SELECT m.*, p.booking_firstname, p.booking_lastname FROM {booking_studygroup_mapping} m " .
					" INNER JOIN {booking_person} p on m.booking_node_id = p.nid " .
					" WHERE booking_eventid = :eid " .
					" AND booking_studygroup_id = :group AND booking_studygroup_role = :role AND booking_session_id = :session",
					array(':eid' => $event->eid, ':group' => $i, ':role' => $otherrole_id, ':session' => $node->$sessionid,
				));
				$otherperson = $otherperson_query->fetchAll();	
				
				watchdog('booking', "<pre>Other person for studygroup !group and role !role result:\n@info</pre>", 
					array('!group' => $i, '!role' => $otherrole_id,  '@info' => print_r( $otherperson, true)));	
					
				foreach ($otherperson as $other)
				{
					$otherperson_name = $other->booking_firstname . ' ' . $other->booking_lastname; 
				}
					

				$rows[] = t('!role for !descrip (section !id). Your !otherrole is !other.', 
					array('!role' => $role, '!id' => $studygroups[$i]->sid, '!descrip' => $studygroups[$i]->booking_studygroup_descrip,
					'!otherrole' => $otherrole, '!other' => $otherperson_name,
				));						

			}				
		}
	}

	foreach ($rows as $key => $value)
	  $rows[$key] = wordwrap($value);

	return implode("\n", $rows);
}

/**
 * Helper function to format summary of room allocation to be used as a token
 */
function _booking_room_email_summary($node) {
	global $event;
	$rows = array();

	//display study session data if enabled
	if (variable_get('booking_enable_roomallocations', 0) == 1)
	{	
		//check that this attendee has had a room allocated
		if (! empty($node->rid))
		{
			$rows[] = t("Room Location: " . _booking_room_location_lookup($node->booking_room_location_id));
			$rows[] = t("Room Number: " . $node->booking_room_number);
			$rows[] = t("Bed Type: " . _booking_room_bedtype_lookup($node->booking_room_bedtype));
		}
		else
			$rows[] = t("\tNo room currently allocated.");
	}

	foreach ($rows as $key => $value)
	  $rows[$key] = wordwrap($value);

	return implode("\n", $rows);
}

/**
* @brief Generates a Universally Unique IDentifier, version 4.
*
* This function generates a truly random UUID. The built in CakePHP String::uuid() function
* is not cryptographically secure. You should uses this function instead.
*
* @see http://tools.ietf.org/html/rfc4122#section-4.4
* @see http://en.wikipedia.org/wiki/UUID
* @return string A UUID, made up of 32 hex digits and 4 hyphens.
*/
 function _booking_uuidSecure() {
 
   $pr_bits = null;
   $fp = @fopen('/dev/urandom','rb');
   if ($fp !== false) {
       $pr_bits .= @fread($fp, 16);
       @fclose($fp);
   } else {
       // If /dev/urandom isn't available (eg: in non-unix systems), use mt_rand().
       $pr_bits = "";
       for($cnt=0; $cnt < 16; $cnt++){
           $pr_bits .= chr(mt_rand(0, 255));
       }
   }
 
   $time_low = bin2hex(substr($pr_bits,0, 4));
   $time_mid = bin2hex(substr($pr_bits,4, 2));
   $time_hi_and_version = bin2hex(substr($pr_bits,6, 2));
   $clock_seq_hi_and_reserved = bin2hex(substr($pr_bits,8, 2));
   $node = bin2hex(substr($pr_bits,10, 6));
 
   /**
    * Set the four most significant bits (bits 12 through 15) of the
    * time_hi_and_version field to the 4-bit version number from
    * Section 4.1.3.
    * @see http://tools.ietf.org/html/rfc4122#section-4.1.3
    */
   $time_hi_and_version = hexdec($time_hi_and_version);
   $time_hi_and_version = $time_hi_and_version >> 4;
   $time_hi_and_version = $time_hi_and_version | 0x4000;
 
   /**
    * Set the two most significant bits (bits 6 and 7) of the
    * clock_seq_hi_and_reserved to zero and one, respectively.
    */
   $clock_seq_hi_and_reserved = hexdec($clock_seq_hi_and_reserved);
   $clock_seq_hi_and_reserved = $clock_seq_hi_and_reserved >> 2;
   $clock_seq_hi_and_reserved = $clock_seq_hi_and_reserved | 0x8000;
 
   return sprintf('%08s-%04s-%04x-%04x-%012s',
       $time_low, $time_mid, $time_hi_and_version, $clock_seq_hi_and_reserved, $node);
}