<?php

/**
 * @file
 * Admin pages for calculating study group session membership
 */


/**
 * Function for selecting who is available to lead or help sessions
 */
function booking_available_leadhelp_select_form($node, &$form_state, $group_id) {
	global $event;
	
	//see http://www.jaypan.com/blog/themeing-drupal-7-forms-tables-checkboxes-or-radios	
	$form = array ();	
	$options = array ();
	$group_options = array();
	$session_options = array();	

	$class_array = array(
		0 => "normal-row",
		1 => "leader-row",
		2 => "helper-row",
		3 => "reserveleader-row",
		4 => "reservehelper-row",		
	);

	//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 edit group leaders and helpers.", 'error', FALSE);
		drupal_goto('admin/booking/studygroups');
		return "";
	}	
	
	//select all the study groups for this event id
	$studygroup = db_query("SELECT * FROM {booking_studygroup_list} WHERE sid = :sid", array(':sid' => $group_id))
		->fetchObject();
	
	if (! $studygroup)
	{
		drupal_set_message("Error: Could not find matching study group ID. Unable to edit leaders/helpers.", 'error', FALSE);
		drupal_goto('admin/booking/studygroups');
		return "";			
	}
	
	$form['#attached']['css'] = array(
	  drupal_get_path('module', 'booking') . '/booking.css',
	);	

	$prefix = t("<h2>Study Group &dash; !descrip</h2><p>Allocate a leader/helper session for attendees.</p>", 
		array('!descrip' => $studygroup->booking_studygroup_descrip));
		
	//select the number of study group sessions
	//assume they all have the same number of sessions
	$num_sessions = $studygroup->booking_num_group_sessions;
	$session_options[0] = '';	
	for ($i = 1; $i <= $num_sessions; $i++)
		$session_options[$i] = $i;
	$session_options['Remove'] = 'Remove';
	
	//select any entries already in the mapping table
	$group_mapping_query = db_query("SELECT * FROM {booking_studygroup_mapping} WHERE booking_eventid = :eid", array(':eid' => $event->eid));
	$group_mapping = $group_mapping_query->fetchAllAssoc('sid');	
	
	//***form starts here***
	$form['booking_studygroup'] = array (
		'#type' => 'hidden',
		'#value' => $group_id,
	);	
	
	$header = array (
		'booking_nid' =>  array('data' => t('Booking ID'), 'field' => 'nid'),
		'booking_name' =>  array('data' => t('Name'), 'field' => 'booking_lastname'),
		'booking_baptised' =>  array('data' => t('Baptised?'), 'field' => 'booking_baptised'),		
		'booking_age' =>  array('data' => t('Age (start of week)'), 'field' => 'booking_dob', 'sort' => 'asc'),
		'booking_state' => array('data' => t('State'), 'field' => 'booking_state'),
		'booking_status' => array('data' => t('Status'), 'field' => 'booking_status'),
		'booking_assign_leader_session' =>  array('data' => t('Leader Session')),		
		'booking_assign_helper_session' =>  array('data' => t('Helper Session')),	
		'booking_assign_reserveleader_session' =>  array('data' => t('Reserve Leader Session')),			
		'booking_currently_leadhelp' =>  array('data' => t('Currently leading/helping')),
		'booking_group_edit' =>  array('data' => t('Edit')),
	);				
					
	$query = db_select('booking_person', 'p');

	//only select people that are either booked in or on the waiting list
	$db_or = db_or();
	$db_or->condition('p.booking_status', 1, '=');
	$db_or->condition('p.booking_status', 2, '=');

	//also restrict to males from the current event
	$db_and = db_and();
	$db_and->condition('p.booking_eventid', $event->eid, '=');
	$db_and->condition('p.booking_gender', 'M', '=');
	$db_and->condition($db_or);

	$query->condition($db_and);
	$query->fields('p');
	//$query->groupBy('booking_gender');
	$table_sort = $query->extend('TableSort')->orderbyHeader($header);
	$result = $table_sort->execute();

	foreach($result as $data)
	{
		$role_listing = "";
		$assigned_role = 0;
		$session_id = 0;
		$class = $class_array[0];
		
		//work out what this person is currently leading/helping
		foreach ($group_mapping as $group)
		{	
			$role = $group->booking_studygroup_role;
			/*
			//add to the listing of all the roles this person is doing
			if ($group->booking_node_id == $data->nid && $role > 0)
			{
				$text = _booking_studygroup_role_lookup($role);
				$role_listing .= $text . " group " . $group->booking_studygroup_id . " #" . $group->booking_session_id . "; ";			
			}	
			*/
			//also record if they are doing anything for our current group		
			if ($group->booking_node_id == $data->nid && $group->booking_studygroup_id == $group_id)
			{
				$assigned_role = $role;
				$session_id = $group->booking_session_id;
				//list any role for this current group
				if ($role > 0) {
					$text = _booking_studygroup_role_lookup($role);
					$role_listing .= "<b>" . $text . "</b> group " . $group->booking_studygroup_id . " #" . $group->booking_session_id . "; ";
					$class = $class_array[$role];									
				}
				
			}
		}		
		
		$options[$data->nid] = array (
			'booking_nid' => l(t('!id', array('!id' => $data->nid)),  t('node/!id', array('!id' => $data->nid))),
			'booking_name' => l(t($data->booking_firstname . " " . $data->booking_lastname),  t('node/!id', array('!id' => $data->nid))),
			'booking_baptised' => $data->booking_baptised == 'Y' ? 'Yes' : 'No',
			'booking_age' => _booking_avg_age($data->booking_dob, 1, $event->booking_event_start),
			'booking_state' => $data->booking_state,
			'booking_status' => _booking_status_generate($data->booking_status),
			'booking_assign_leader_session' => array('data' => array(
				'#type' => 'select',
				'#options' => $session_options,
				'#name' => 'booking_assign_leader_session[' . $data->nid . ']',	
				'#value' => $assigned_role == 1 ? $session_id : 0,
				) 
			),
			'booking_assign_helper_session' => array('data' => array(
				'#type' => 'select',
				'#options' => $session_options,
				'#name' => 'booking_assign_helper_session[' . $data->nid . ']',	
				'#value' => $assigned_role == 2 ? $session_id : 0,
				) 
			),
			'booking_assign_reserveleader_session' => array('data' => array(
				'#type' => 'select',
				'#options' => $session_options,
				'#name' => 'booking_assign_reserveleader_session[' . $data->nid . ']',	
				'#value' => $assigned_role == 3 ? $session_id : 0,
				) 
			),			
			'booking_currently_leadhelp' => $role_listing,	
			'booking_group_edit' => l(t('Edit'), t('admin/booking/!id/edit-studygroup-membership', array('!id' => $data->nid))),		
			'#attributes' => array('id' => array($class)),	
		);
	}	

	$form['table'] = array (
		'#type' => 'tableselect',
		'#header' => $header,
		'#options' => $options,
		'#empty' => t('No attendees found.'),
		'#attributes' => array('id' => 'sort-table'),
	);
	
	//so we can access the dropdown elements
	$form['booking_assign_leader_session'] = array( '#type' => 'value', );
	$form['booking_assign_reserveleader_session'] = array( '#type' => 'value', );
	$form['booking_assign_helper_session'] = array( '#type' => 'value', );
	

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

	return array (
		'first_para' => array (
			'#type' => 'markup',
			'#markup' => $prefix,
		),
		'form' => $form,		
	);
}

/**
 * Validate the submission for defining which study group sessions people will lead or help
 */
function booking_available_leadhelp_select_form_validate($form, &$form_state) {

	//check that a study group was selected
	if ($booking_studygroup = $form_state['values']['booking_studygroup'] == 0)
	{
		form_set_error('booking_studygroup', 
			t('You forgot to select which study group to apply this list to.')
		);		
	}

}

/**
 * Process the submission for number of study group sessions to lead/help
 */
function booking_available_leadhelp_select_form_submit($form, &$form_state) {
	global $event;
	$counter = 0;
	$checkboxes = $form_state['values']['table'];
	$booking_studygroup = $form_state['values']['booking_studygroup'];
	
	$leader_session = $form_state['values']['booking_assign_leader_session'];
	$reserve_leader_session = $form_state['values']['booking_assign_reserveleader_session'];	
	$helper_session = $form_state['values']['booking_assign_helper_session'];
	
	//watchdog('booking', "Leader list: @info", array('@info' => var_export($form_state['values'], TRUE)));
	//watchdog('booking', "Helper list: @info", array('@info' => var_export($reserve_leader_session, TRUE)));
	
	//select any entries already in the mapping table
	$group_mapping_query = db_query("SELECT * FROM {booking_studygroup_mapping} WHERE booking_eventid = :eid", array(':eid' => $event->eid));
	$group_mapping = $group_mapping_query->fetchAllAssoc('sid');	
	
	//update the attendees as specified
	foreach($checkboxes as $key => $value)
	{
		$leader = 'N';
		$helper = 'N';
		$reserve_leader = 'N';
		$session = 0;
		$role = 0;
		$found = FALSE;

		//remove from being a leader?
		if ($leader_session[$key] == "Remove") {
			$num_deleted = db_delete('booking_studygroup_mapping')
				->condition('booking_eventid', $event->eid)
				->condition('booking_node_id', $key)
				->condition('booking_studygroup_id', $booking_studygroup)
			 	->execute();
			watchdog('booking', 'Removed person !nid from being a leader in study group !sid, affected !num rows.', 
				array ('!nid' => $key, '!sid' => $booking_studygroup, '!num' => $num_deleted));	
			//skip to the next person
			$counter++;	
			continue;
		}
		//remove from being a helper?
		elseif ($helper_session[$key] == "Remove") {
			$num_deleted = db_delete('booking_studygroup_mapping')
				->condition('booking_eventid', $event->eid)
				->condition('booking_node_id', $key)
				->condition('booking_studygroup_id', $booking_studygroup)
			 	->execute();
			watchdog('booking', 'Removed person !nid from being a helper in study group !sid, affected !num rows.', array ('!nid' => $key, '!sid' => $booking_studygroup, '!num' => $num_deleted));		
			//skip to the next person
			$counter++;	
			continue;				
		}
		//remove from being a reserve leader?
		elseif ($reserve_leader_session[$key] == "Remove") {
			$num_deleted = db_delete('booking_studygroup_mapping')
				->condition('booking_eventid', $event->eid)
				->condition('booking_node_id', $key)
				->condition('booking_studygroup_id', $booking_studygroup)
			 	->execute();
			watchdog('booking', 'Removed person !nid from being a reserve leader in study group !sid, affected !num rows.', 
					array ('!nid' => $key, '!sid' => $booking_studygroup, '!num' => $num_deleted));		
			//skip to the next person
			$counter++;	
			continue;				
		}		
		//was this person set as a leader?
		elseif ($leader_session[$key] <> 0)
		{
			$role = 1;
			$session = $leader_session[$key];
			watchdog('booking', 'Person !nid is set to be a leader in session !sid, group !group', 
				array ('!nid' => $key, '!sid' => $leader_session[$key], '!group' => $booking_studygroup));
		}
		//was this person set as a helper?
		elseif ($helper_session[$key] <> 0)
		{
			$role = 2;
			$session = $helper_session[$key];
			watchdog('booking', 'Person !nid is set to be a helper in session !sid, group !group', 
				array ('!nid' => $key, '!sid' => $helper_session[$key], '!group' => $booking_studygroup));
		}	
		elseif ($reserve_leader_session[$key] <> 0)
		{
			$role = 3;
			$session = $reserve_leader_session[$key];
			watchdog('booking', 'Person !nid is set to be a reserve leader in session !sid, group !group', 
				array('!nid' => $key, '!sid' => $helper_session[$key], '!group' => $booking_studygroup));
		}				
		//if we reach the else something weird happened, make sure we don't insert
		else
			continue;
		
		//check if this person already exists in the booking_studygroup_mapping table
		foreach ($group_mapping as $person)
		{
			if ($person->booking_node_id == $key && $person->booking_studygroup_id == $booking_studygroup)
				{
					$found = TRUE;
					break;
				}
		}
		
		if ($found == FALSE) {
			//run an insert
			db_insert('booking_studygroup_mapping')
				->fields(array(	
				    'booking_eventid' => $event->eid,
					'booking_node_id' => $key,
					'booking_studygroup_id' => $booking_studygroup,
					'booking_session_id' => $session,
					'booking_studygroup_role' => $role,
			  ))
			  ->execute();	
		}
		else {
			//run an update
			db_update('booking_studygroup_mapping')
			->fields(array (
				'booking_session_id' => $session,
				'booking_studygroup_role' => $role,
				))
			->condition('booking_node_id', $key)
			->condition('booking_studygroup_id', $booking_studygroup)
			->execute();			
		}
		
		$counter++;					
	}
	
	$message = t("Processed !num leader/helper sessions for group id !id", array('!num' => $counter, '!id' => $booking_studygroup));
	drupal_set_message($message, 'status', FALSE);
	watchdog('booking', $message);	
}


/**
 * Function for manually assigning study group sessions for a person
 */
function booking_studygroups_edit_form($node, &$form_state, $nid) {
	global $event;
	
	//see http://www.jaypan.com/blog/themeing-drupal-7-forms-tables-checkboxes-or-radios	
	$form = array ();	
	$rows = array ();
	$session_options = array();	
	$readinggroup_options = array();
	$session_options[0] = '';	
	$readinggroup_options[0] = '';
	
	//verify that $nid is a number
	if (! preg_match('/^[0-9]+$/', $nid)) {
		drupal_set_message("Error: Invalid registration ID '" . $nid . "' supplied. Unable to edit study group sessions.", 'error', FALSE);
		drupal_goto('admin/booking/studygroups');
		return "";
	}
	
	//check that this person exists
    $person = db_query("SELECT person.nid, person.booking_firstname, person.booking_lastname " .
				"FROM     {booking_person} person " .
				"WHERE nid = :nid", 
				array(':nid' => $nid))
				->fetchObject();	
	//throw an error if they don't exist			
	if (! $person)
	{
		drupal_set_message("Error: Unable to find booking corresponding with registration ID '" . $nid . "'.", 'error', FALSE);
		drupal_goto('admin/booking/studygroups');
		return "";		
	}
	
	$prefix = t("<p>Manually assign/update study group sessions for !first !last.<br />If updating an existing session ID, this will also copy any role assigned (leader, helper, etc).</p>", array('!first' => $person->booking_firstname, '!last' => $person->booking_lastname));	
	
	//select the groups this person is already assigned to, indexed by studygroup id
	$person_groups_query = db_query("SELECT * FROM {booking_studygroup_mapping} WHERE booking_eventid = :eid AND booking_node_id = :nid", 
					array(':eid' => $event->eid, ':nid' => $nid));
	$person_groups = $person_groups_query->fetchAllAssoc('booking_studygroup_id');						
					
	//select all the study groups for this event id
	$studygroups_query = db_query("SELECT * FROM {booking_studygroup_list} WHERE booking_eventid = :eid", array(':eid' => $event->eid));
	$studygroups = $studygroups_query->fetchAll();
	
	//retrieve the number of study group sessions, assume they all have the same number of sessions
	$num_sessions = reset($studygroups)->booking_num_group_sessions;
	//create the array for our html select fields
	for ($i = 1; $i <= $num_sessions; $i++) {
		$session_options[$i] = $i;
		$readinggroup_options[$i] = _booking_readinggroup_colour_lookup($i);
	}
	$session_options['Remove'] = 'Remove';
	$readinggroup_options['Remove'] = 'Remove';
	
	//select any entries already in the mapping table
	$group_mapping_query = db_query("SELECT * FROM {booking_studygroup_mapping} WHERE booking_eventid = :eid", array(':eid' => $event->eid));
	$group_mapping = $group_mapping_query->fetchAllAssoc('sid');	
	
	//***form starts here***
	$header = array(
		'booking_studygroup_descrip' => array('data' => t('Study Group')),	
		'booking_current_session_id' => array('data' => t('Current Session Number')),	
		'booking_session_id' => array('data' => t('Select Session Number')),
	);	
	
	//create a new row for each group
	foreach ($studygroups as $group)
	{
		$default = '';
		$role = '';
		
		//retrieve the current session id for this group if defined already
		if (! empty($person_groups[$group->sid]))
		{
			$default = $person_groups[$group->sid]->booking_session_id;
			//check if the person has an assigned role for this session
			
			$role = _booking_studygroup_role_lookup($person_groups[$group->sid]->booking_studygroup_role) . " Session #";
			
			/*
			if ($person_groups[$group->sid]->booking_is_leader == 'Y')
				$role = "Leader Session #";
			elseif ($person_groups[$group->sid]->booking_is_helper == 'Y')
				$role = "Helper Session #";
			elseif ($person_groups[$group->sid]->booking_is_reserveleader == 'Y')
				$role = "Reserve Leader Session #";	
			*/		
		}
		
		//if ($group->sid == variable_get('booking_readinggroup_id','7'))
		if ($group->booking_is_readinggroup == 'Y')
		{
			$options = $readinggroup_options;
		}
		else
		{
			$options = $session_options;
		}
		
		$rows[] = array (
			'booking_studygroup_descrip' => $group->booking_studygroup_descrip,
			'booking_current_session_id' => $default == '' ? 'Not Set' : $role . $default,
			'booking_session_id' => array('data' => array(
				'#type' => 'select',
				'#options' => $options,
				'#value' => $default,				
				'#name' => 'booking_assign_sessionid[' . $group->sid . ']',	
				) 
			),		
		);		
	}	
	
	//so we can access the dropdown elements
	$form['booking_assign_sessionid'] = array( '#type' => 'value', );	

	//generate the render array
	$form['personid'] = array(
		'#type' => 'hidden',
		'#value' => $nid,
	);	
	$form['table'] = array (
		'#type' => 'tableselect',
		'#header' => $header,
		'#options' => $rows,
	);
	$form['submit'] = array (
		'#type' => 'submit',
		'#value' => t('Submit'),
	);	

	return array (
		'first_para' => array (
			'#type' => 'markup',
			'#markup' => $prefix,
		),
		'form' => $form,		
	);
}


/**
 * Process the submission to manually assign study group sessions for a person
 */
function booking_studygroups_edit_form_submit($form, &$form_state) {
	global $event;
	$counter = 0;
	//$checkboxes = $form_state['values']['table'];
	$studygroup_ids = $form_state['values']['booking_assign_sessionid'];
	$values = $form_state['input'];
	$update_messages = array();
	
	//check that $values['personid'] is a number
	if (! preg_match('/^[0-9]+$/', $values['personid'])) {
		//parameter from url is not what we were expecting
		drupal_set_message("Error: Invalid form data supplied. Please use the contact us form to let us know.", 'error', FALSE);
		return "";
	}
	$nid = $values['personid'];	
	
	//watchdog('booking', "<pre>Study Groups Edit submission:\n@info</pre>", array('@info' => print_r( $form_state, true)));

	//select the groups this person is already assigned to, indexed by studygroup id
	$person_groups_query = db_query("SELECT * FROM {booking_studygroup_mapping} WHERE booking_eventid = :eid AND booking_node_id = :nid", 
					array(':eid' => $event->eid, ':nid' => $nid));
	$person_groups = $person_groups_query->fetchAllAssoc('booking_studygroup_id');

	//select any readings groups so we know if we need to update colours
	$reading_groups_query = db_query("SELECT * FROM {booking_studygroup_list} WHERE booking_eventid = :eid AND booking_is_readinggroup = 'Y'", array(':eid' => $event->eid));
	$reading_groups = $reading_groups_query->fetchAllAssoc('sid');	
	
	//loop through array of study group IDs and compare against existing database entries
	foreach ($studygroup_ids as $key => $value) {
		//watchdog('booking', "<pre>Study Group key:\n@key\nValue\n@value</pre>", array('@key' => print_r( $key, true), '@value' => print_r( $value, true)));

		//check if there is a valid value to process
		if ($value > 0 || $value == 'Remove') {
			//if there was no previous mapping but Remove has been selected anyway, just skip to the next value to look at
			if (empty($person_groups[$key]) && $value == 'Remove')
			{
				continue;
			}
			//check to see if we need to remove a study group mapping
			if (! empty($person_groups[$key]) && $value == 'Remove') {
				$update_messages[] = t("Removing an existing Study Group session id: @id from group @group.\n<pre>@info</pre>", 
					array('@id' => $value, '@group' => $key, '@info' => print_r( $person_groups[$key], true)));
				
				$num_deleted = db_delete('booking_studygroup_mapping')
					->condition('sid', $person_groups[$key]->sid)
				 	->execute();				
			}
			//check for an existing study group mapping to change
			elseif ((!empty($person_groups[$key])) && $person_groups[$key]->booking_session_id != $value) {
				$update_messages[] = t( "Updating Study Group session from: @key to @value for id @id", 
					array('@key' => $person_groups[$key]->booking_session_id, '@value' => $value, '@id' => $nid));

				db_update('booking_studygroup_mapping')
				  ->fields(array(
					'booking_session_id' => $value,
					'booking_studygroup_role'  => $person_groups[$key]->booking_studygroup_role,
					'booking_session_manually_allocated' => 'Y',
					))
				  ->condition('sid', $person_groups[$key]->sid)
				  ->execute();

				//check if there is a readings group colour to update
				foreach ($reading_groups as $group) {
					if ($group->sid == $key) {
						booking_studygroups_process_colours();
						break;
					}
				}
			}
			//found this entry already, so no change needed
			elseif ((!empty($person_groups[$key])) && $person_groups[$key]->booking_session_id == $value) {
				$update_messages[] = t("Study Group @group session already set to @session.", 
					array('@group' => $key, '@session' => $value));				
			}			
			//no previously defined value, so add a new entry to the mapping table			
			else {
				$update_messages[] = t("Adding Study Group session id: @id for group @group.", array('@id' => $value, '@group' => $key));

				db_insert('booking_studygroup_mapping')
					->fields(array(	
					  'booking_eventid' => $event->eid,
						'booking_node_id' => $nid,
						'booking_studygroup_id' => $key,
						'booking_session_id' => $value,
						'booking_studygroup_role' => 0,
						'booking_session_manually_allocated' => 'Y',
				  ))
				  ->execute();
				//check if there is a readings group colour to update
				foreach ($reading_groups as $group) {
					if ($group->sid == $key) {
						booking_studygroups_process_colours();
						break;
					}
				}
			}	//end new value check
		}		//end valid data check		
	}			//end select dropdown loop
	//output messages to watchdog
	$final_message = t('Finished processing study groups for person id !id.', array('!id' => $nid));
	drupal_set_message($final_message);
	watchdog('booking', "<pre>" . $final_message . "\n" . implode("\n", $update_messages) . "</pre>");	
}	//end function

/**
 * Function for calculating who belongs to which study group
 */
function booking_studygroups_update_form($node, &$form_state, $sid) {
	global $event;
	
	//master attendee list
	$attendees = array();
	//temporary working copy of attendee list
	$working_list = array();
	//create an array to keep track of the number of people in each session for each group
	$session_count = array();
	//the form to return
	$form = array();
	$calculation_messages = array();
	$update_messages = array();
	$prefix = "";
	$intro_text = "";
	//$reading_group_id = variable_get('booking_readinggroup_id','7');
	
	//store our calculated updates in this array which will then get serialized and added to the form for processing
	$updates_to_confirm = array();
	$inserts_to_confirm = array();

	//verify that $nid is a number
	if (! preg_match('/^[0-9]+$/', $sid)) {
		drupal_set_message("Error: Invalid group ID '" . $sid . "' supplied. Unable to update study group session.", 'error', FALSE);
		drupal_goto('admin/booking/studygroups');
		return "";
	}

	//select the study group for the supplied ID
	//$studygroups_query = db_query("SELECT * FROM {booking_studygroup_list} WHERE booking_eventid = :eid", array(':eid' => $event->eid));
	$studygroups_query = db_query("SELECT * FROM {booking_studygroup_list} WHERE sid = :sid", array(':sid' => $sid));
	$studygroups = $studygroups_query->fetchAllAssoc('sid');
	
	//select any entries already in the mapping table
	$group_mapping_query = db_query("SELECT * FROM {booking_studygroup_mapping} WHERE booking_eventid = :eid AND booking_studygroup_id = :sid", array(':eid' => $event->eid, ':sid' => $sid));
	$group_mapping = $group_mapping_query->fetchAllAssoc('sid');
	
	//throw an error if we got no groups	
	if (! $studygroups) {
		drupal_set_message("Error: Unable to find group with corresponding ID '" . $sid . "'.", 'error', FALSE);
		drupal_goto('admin/booking/studygroups');
		return "";		
	}		
	
	//calculate the max number of attendees in a group
	$firstgroup = reset($studygroups);
	$limit = variable_get('booking_regn_limit','500');
	//be a bit more lenient with maximums to avoid excessive re-arrangement of groups
	$fudge_factor = 0;
	$max_people = (int) ($limit / $firstgroup->booking_num_group_sessions) + $fudge_factor;

	//select all the attendees for this event
	$query = db_query("SELECT * FROM {booking_person} WHERE booking_eventid = :eid", 
					array(':eid' => $event->eid));
	$attendees = $query->fetchAllAssoc('nid');	
	
	//TODO: Move statistics generation to separate function
	//calculate the ratios of males to females, and various age groups
	$statistics = _booking_generate_statistics($attendees);
	
	if ($statistics['males'] == 0 || $statistics['females'] == 0 || $max_people == 0) {
		$gender_ratio = 1;
	}
	else {
		$gender_ratio = ($statistics['males'] / $statistics['females']) * ($max_people / 2);		
	}
	
	//really stretch the tolerances for placement by setting this to zero
	$fudge_factor = 1;
	//store our final maximums as an array for easy access later
	$maximums = array(
		'male' => ceil($gender_ratio),
		'female' => ceil($max_people - $gender_ratio),
		'under20' => ceil(($statistics['under20'] / $limit) * ($max_people - $fudge_factor)),
		'20to25' => ceil(($statistics['20to25'] / $limit) * ($max_people - $fudge_factor)),
		'over25' => ceil(($statistics['over25'] / $limit) * ($max_people - $fudge_factor)),		
	);

	//remove the mappings for people no longer coming
	_booking_studygroup_cleanup();
	
	//iterate over the attendee associative array and add some fields	
	foreach ($attendees as $person) {
		//flag that indicates processed or not
		$person->processed = 0;
		//field that indicates the session id the person is assigned to	
		$person->session = 0;
		$person->booking_studygroup_role = 0;

		//make sure we skip attendees that do not have the status of "booked in"
		if ($person->booking_status <> 1) {
			$person->processed = 1;
		}
	}
	
	//watchdog('booking', "<pre>Attendee list:\n@info</pre>", array('@info' => print_r( $attendees, true)));
	//watchdog('booking', "Attendee list: @info", array('@info' => var_export($attendees, TRUE)));

	//process each study group (eg Monday Tuesday Wednesday etc)
	foreach ($studygroups as $group) {
		$prefix .= t('<h2>Processing study group !group with !sessions sessions</h2>', 
			array('!group' => $group->booking_studygroup_descrip, '!sessions' => $group->booking_num_group_sessions));
		$prefix .=  t('<p>Aiming for !males males, !females females in group. Made up of !20s under 20, !low20s between 20 and 25, and !high20s over 25. Total count in group is !max.</p>', 
			array('!20s' => $maximums['under20'], '!low20s' => $maximums['20to25'], '!high20s' => $maximums['over25'],
			'!males' => $maximums['male'], '!females' => $maximums['female'], '!max' => $max_people)
		);
		
		//create a temporary copy of the attendee list to work with for this study group
		$working_list = array();
		$working_list = _booking_shuffle_assoc(_booking_clone_array($attendees));
		
		//set up the iterator
		$obj = new ArrayObject( $working_list );
		$iterator = $obj->getIterator();		
		
		//clear the array keeping track of the number of people in each session for this group
		for ($i = 1; $i <= $group->booking_num_group_sessions; $i++) {
			$session_count[$i] = array(
				'total' => 0,
				'male' => 0,
				'female' => 0,
				'under20' => 0,
				'20to25' => 0,
				'over25' => 0,				
			);
		}

		//search for the leaders helpers, spouses and boyfriend/girlfriend for this study group to pre-allocate	
		_booking_studygroups_update_preallocate($group, $group_mapping, $session_count, $working_list, $calculation_messages);

		//watchdog('booking', "<pre>Attendee list working copy after pre-processing:\n@info</pre>", array('@info' => print_r( $working_list, true)));
		//watchdog('booking', "Attendee list working copy after leader/helper spouse processing: @info", array('@info' => var_export($working_list, TRUE)));
		//watchdog('booking', "Attendee list session count after leader/helper spouse processing: @info", array('@info' => var_export($session_count, TRUE)));
		//watchdog('booking', "Attendee list: @info", array('@info' => var_export($attendees, TRUE)));
		//watchdog('booking', "Attendee list working copy: @info", array('@info' => var_export($working_list, TRUE)));
		//watchdog('booking', "Attendee list distribution: @info", array('@info' => var_export($session_count, TRUE)));		

		//allocate everyone else to a session
		_booking_studygroups_update_allocate($iterator, $max_people, $maximums, $group, $group_mapping, $session_count, $working_list, $calculation_messages);		

		//now calculate the updates for the database
		foreach($working_list as $person) {
			$found = FALSE;
			$message = "";			
			
			//iterate all the groups for each person
			foreach ($group_mapping as $mapping) {
				//check if we can find a study group session already for this user and this study group (eg Monday Tuesday or Wednesday)
				if ($person->nid == $mapping->booking_node_id && $group->sid == $mapping->booking_studygroup_id) {
					//keep track of our success to avoid doing an insert
					$found = TRUE;
					
					//if the existing session is not the same as our newly calculated session, run an update query
					//if ($mapping->booking_session_id !== $person->session && $group->sid != $reading_group_id)
					if ($mapping->booking_session_id !== $person->session && $group->booking_is_readinggroup == 'N') {
						$message = t('Suggest changing user !id (!name) from session !old to !session. Role id is !role', 
							array('!id' => $person->nid, '!old' => $mapping->booking_session_id, '!session' => $person->session, 
							'!role' => $person->booking_studygroup_role, '!name' => $person->booking_firstname . " " . $person->booking_lastname));
						
						$update = array(
							'booking_session_id' => $person->session,
							'booking_studygroup_role' => $person->booking_studygroup_role,					
							);
						
						$updates_to_confirm[] = array('sid' => $mapping->sid, 'fields' => $update);

					}
					//elseif ($mapping->booking_session_id !== $person->session && $group->sid == $reading_group_id)
					elseif ($mapping->booking_session_id !== $person->session && $group->booking_is_readinggroup == 'Y') {
						$message = t('Suggest changing user !id (!name) from reading group session !old to !session. Role id is !role', 
							array('!id' => $person->nid, '!old' => $mapping->booking_session_id, '!session' => $person->session, 
							'!role' => $person->booking_studygroup_role, '!name' => $person->booking_firstname . " " . $person->booking_lastname));

						$update = array(
							'booking_session_id' => $person->session,
							'booking_studygroup_role' => $person->booking_studygroup_role,					
							);
						
						$updates_to_confirm[] = array('sid' => $mapping->sid, 'fields' => $update);											
	
					}					
					//stop looping through the list since we found a match
					break;
					
				}	//end checking for existing group session
			}		//end looping through study group mappings
			
			//if we didn't find an existing record, add it to the list to insert
			if (! $found && $person->session <> 0) {
				$message = t('Found no existing study group session for user id !id (!name). Adding to list of inserts for session !session.', 
					array('!id' => $person->nid, '!sid' => $mapping->sid, '!session' => $person->session,
					'!name' => $person->booking_firstname . " " . $person->booking_lastname
				));
				
				$inserts_to_confirm[] = array(
					'booking_eventid' => $event->eid,
					'booking_node_id' => $person->nid,
					'booking_studygroup_id' => $group->sid,
					'booking_session_id' => $person->session,
					'booking_studygroup_role' => $person->booking_studygroup_role,
				);				
				
			}
			
			//log any update we made
			if ($message !== "") {
				$update_messages[] = $message;							
				//watchdog('booking', $message);						
			}
			
		}	//end loop through working copy of attendee list		
		
		//watchdog('booking', "<pre>Session statistics list:\n@info</pre>", array('@info' => print_r( $session_count, true)));
		
		//clear the arrays we've been using for this iteration
		unset($session_count);
		unset($working_list);
		
		$final_message = t('Finished processing study group !group.', array('!group' => $group->booking_studygroup_descrip));
		drupal_set_message($final_message);
		watchdog('booking', "<pre>" . $final_message . "\n" . implode("\n", $update_messages) . "</pre>");
		
		//make sure to update team colours if necessary
		if ($group->booking_is_readinggroup == 'Y') {
			booking_studygroups_process_colours();
		}
	}	//finished processing study groups	
	
	//watchdog('booking', "Attendee list final version: @info", array('@info' => var_export($attendees, TRUE)));
	
	$form['log'] = array(
		'#type' => 'fieldset',
		'#title' => 'Calculated Actions',
		'#collapsible' => TRUE, 
		'#collapsed' => TRUE,
	);	
	$form['log']['messages'] = array(
		'#type' => 'item',
		'#title' => '',
		'#markup' => "<p>" . implode("<br />\n", $calculation_messages) . "</p>",
	);
	$form['result'] = array(
		'#type' => 'fieldset',
		'#title' => 'Suggested Updates',
		'#collapsible' => TRUE, 
		'#collapsed' => FALSE,
	);			
	$form['result']['messages'] = array(
		'#type' => 'item',
		'#title' => '',
		'#markup' => "<p>" . implode("<br />\n", $update_messages) . "</p>",
	);	
	$form['update_string'] = array (
		'#type' => 'hidden',
		'#value' => serialize($updates_to_confirm),
	);	
	$form['insert_string'] = array (
		'#type' => 'hidden',
		'#value' => serialize($inserts_to_confirm),
	);		
	$form['confirm'] = array (
		'#type' => 'submit',
		'#value' => t('Confirm Updates'),
	);		
	return array (
		'first_para' => array (
			'#type' => 'markup',
			'#markup' => $prefix,
		),
		'form' => $form,				
	);	
}

/**
 * Pre-process attendee list to mark attendees that should be placed based on certain criteria rather than assigned based on age/gender
 * Criteria include leader/helper role, spouse, relationship, committee member
 * @see booking_studygroups_update_form()
 */
function _booking_studygroups_update_preallocate($group, $group_mapping, &$session_count, &$working_list, &$calculation_messages) {
	//search for the leaders helpers, spouses and boyfriend/girlfriend for this study group to pre-allocate
	foreach ($group_mapping as $person) {
		//dereference a bunch of fields we'll be using
		$committee_flag = $working_list[$person->booking_node_id]->booking_committee_member;
		$manually_allocated_flag = $person->booking_session_manually_allocated;
		$spouse_id = $working_list[$person->booking_node_id]->booking_partner_id;
		$bf_gf_id = $working_list[$person->booking_node_id]->booking_bf_gf_nid;
		$keep_separate_id = $working_list[$person->booking_node_id]->booking_keepseparate_id;
		$gender = $working_list[$person->booking_node_id]->booking_gender == 'M' ? 'male' : 'female';
		$session_id = $person->booking_session_id;
					
		//if the study group id matches the group we're currently looking at
		if ($person->booking_studygroup_id == $group->sid) {
			//if they have a role defined 
			//or if they are a committee member
			//or if the manually allocated flag is set 
			//then make sure they stay where they are
			if (($person->booking_studygroup_role > 0) || 
				($committee_flag == 'Y') ||
				($manually_allocated_flag == 'Y')) {
					
				$calculation_messages[] = t('Leader/helper/committee/manual allocation with id !id pre-allocated to session !session (currently with !num people).', 
					array('!id' => $person->booking_node_id, '!session' => $person->booking_session_id, 
					'!num' => $session_count[$person->booking_session_id]['total'])
				);
				
				//mark this position as being used
				$working_list[$person->booking_node_id]->booking_studygroup_role = $person->booking_studygroup_role;
				$age = _booking_get_age_years($working_list[$person->booking_node_id]->booking_dob);
				_booking_assign_attendee_group($person->booking_node_id, $session_id, $gender, $age, $working_list, $session_count, $calculation_messages);

				//check if there is someone that should be allocated to a different group than this person
				if ($keep_separate_id > 0) {
					//work out the next session to assign the other person to
					$next_session = ($session_id % $group->booking_num_group_sessions) + 1;

					$calculation_messages[] = t('Keeping person with id !id separate from !separate by assigning !separate to session !session (currently with !num people).', 
						array('!id' => $person->booking_node_id, '!session' => $next_session, '!separate' => $keep_separate_id,
						'!num' => $session_count[$person->booking_session_id]['total'])
					);			
					$age = _booking_get_age_years($working_list[$keep_separate_id]->booking_dob);	
					$gender = $working_list[$keep_separate_id]->booking_gender == 'M' ? 'male' : 'female';	
					_booking_assign_attendee_group($keep_separate_id, $next_session, $gender, $age, $working_list, $session_count, $calculation_messages);							
				}
						
				//make sure the leader/helper's partner gets updated now, otherwise they could still end up in different groups
				if ($spouse_id > 0) {					
					//also mark their spouse as allocated to this group
					$calculation_messages[] = t('Spouse with id !id assigned to session !session (currently with !num people).', 
						array('!id' => $spouse_id, '!session' => $person->booking_session_id, 
						'!num' => $session_count[$person->booking_session_id]['total'])
					);			
					$age = _booking_get_age_years($working_list[$spouse_id]->booking_dob);	
					$spouse_gender = $working_list[$spouse_id]->booking_gender == 'M' ? 'male' : 'female';	
					_booking_assign_attendee_group($spouse_id, $session_id, $spouse_gender, $age, $working_list, $session_count, $calculation_messages);					
				}
				elseif ($bf_gf_id > 0) {					
					//also mark their boyfriend/girlfriend as allocated to this group					
					$calculation_messages[] = t('BF/GF with id !id assigned to session !session (currently with !num people).', 
						array('!id' => $bf_gf_id, '!session' => $person->booking_session_id, 
						'!num' => $session_count[$person->booking_session_id]['total'])
					);	
					$age = _booking_get_age_years($working_list[$bf_gf_id]->booking_dob);
					$bfgf_gender = $working_list[$bf_gf_id]->booking_gender == 'M' ? 'male' : 'female';		
					_booking_assign_attendee_group($bf_gf_id, $session_id, $bfgf_gender, $age, $working_list, $session_count, $calculation_messages);					
				}				
			}
			//check for keep together/apart assignments for people that aren't leaders/helpers/committee
			elseif ($working_list[$person->booking_node_id]->processed == 0) {	
				//check if there is someone that should be allocated to a different group than this person
				if ($keep_separate_id > 0) {
					//work out the next session to assign the other person to
					$next_session = ($session_id % $group->booking_num_group_sessions) + 1;

					$calculation_messages[] = t('Keeping non leader/helper/committee person with id !id separate from !separate by ' . 
						'assigning !id to session !session and !separate to session !nextsession (currently with !num people).', 
						array('!id' => $person->booking_node_id, '!session' => $person->booking_session_id, '!nextsession' => $next_session, 
						'!separate' => $keep_separate_id, '!num' => $session_count[$session_id]['total'],
						'!separatenum' => $session_count[$next_session]['total'])
					);
					//the current person
					$age = _booking_get_age_years($working_list[$person->booking_node_id]->booking_dob);
					_booking_assign_attendee_group($person->booking_node_id, $session_id, $gender, $age, $working_list, $session_count, $calculation_messages);	
					//the separated person				
					$age = _booking_get_age_years($working_list[$keep_separate_id]->booking_dob);	
					$gender = $working_list[$keep_separate_id]->booking_gender == 'M' ? 'male' : 'female';	
					_booking_assign_attendee_group($keep_separate_id, $next_session, $gender, $age, $working_list, $session_count, $calculation_messages);							
				}
				//if there is a spouse or bf/gf then keep them together
				if ($spouse_id > 0) {
					//if the spouse has already been processed due to being a leader or helper, use that session
					if ($working_list[$spouse_id]->processed == 1) {
						$session_id = $working_list[$spouse_id]->session;
					}
					
					//mark this person as allocated to this group
					$calculation_messages[] = t('Married person with id !id assigned to session !session (currently with !num people).', 
						array('!id' => $person->booking_node_id, '!session' => $person->booking_session_id, 
						'!num' => $session_count[$person->booking_session_id]['total'])
					);
					$age = _booking_get_age_years($working_list[$person->booking_node_id]->booking_dob);
					_booking_assign_attendee_group($person->booking_node_id, $session_id, $gender, $age, $working_list, $session_count, $calculation_messages);
										
					//also mark their spouse as allocated to this group
					$calculation_messages[] = t('Spouse with id !id assigned to session !session (currently with !num people).', 
						array('!id' => $spouse_id, '!session' => $person->booking_session_id, 
						'!num' => $session_count[$person->booking_session_id]['total'])
					);			
					$age = _booking_get_age_years($working_list[$spouse_id]->booking_dob);	
					$spouse_gender = $working_list[$spouse_id]->booking_gender == 'M' ? 'male' : 'female';	
					_booking_assign_attendee_group($spouse_id, $session_id, $spouse_gender, $age, $working_list, $session_count, $calculation_messages);					
				}
				elseif ($bf_gf_id > 0) {
					//if the bf/gf has already been processed due to being a leader or helper, use that session
					if ($working_list[$bf_gf_id]->processed == 1) {
						$session_id = $working_list[$bf_gf_id]->session;
					}

					//mark this person as allocated to this group
					$calculation_messages[] = t('Person with id !id in relationship assigned to session !session (currently with !num people).', 
						array('!id' => $person->booking_node_id, '!session' => $person->booking_session_id, 
						'!num' => $session_count[$person->booking_session_id]['total'])
					);
					$age = _booking_get_age_years($working_list[$person->booking_node_id]->booking_dob);
					_booking_assign_attendee_group($person->booking_node_id, $session_id, $gender, $age, $working_list, $session_count, $calculation_messages);
										
					//also mark their boyfriend/girlfriend as allocated to this group					
					$calculation_messages[] = t('BF/GF with id !id assigned to session !session (currently with !num people).', 
						array('!id' => $bf_gf_id, '!session' => $person->booking_session_id, 
						'!num' => $session_count[$person->booking_session_id]['total'])
					);	
					$age = _booking_get_age_years($working_list[$bf_gf_id]->booking_dob);
					$bfgf_gender = $working_list[$bf_gf_id]->booking_gender == 'M' ? 'male' : 'female';		
					_booking_assign_attendee_group($bf_gf_id, $session_id, $bfgf_gender, $age, $working_list, $session_count, $calculation_messages);					
				}	
				//for anyone else, just record what session they're currently in
				else {
					$working_list[$person->booking_node_id]->session = $session_id;
				}			
			}		//end looking at people with spouse or bf/gf
		}		//end checking for matching study group id
	}			//end searching for people to pre-allocate

}

/**
 * Process attendee list to allocate attendees to study group sessions based on statistical breakdown of attendees
 * @see booking_studygroups_update_form()
 */
function _booking_studygroups_update_allocate($iterator, $max_people, $maximums, $group, $group_mapping, &$session_count, &$working_list, &$calculation_messages) {
	$starting_session = 0;
	
	//reset the iterator to starting position
	$iterator->rewind();

	//initialise our counters
	//$session_id = 1;
	$i = 1;
	
	//iterate over the attendee list
	while ($iterator->valid()) {		
		//cycle the session counter if we already reached the end
		if ($i > $group->booking_num_group_sessions) {
			$i = 1;		
		}

		//get the current attendee element
		$current = $iterator->current();		

		//assign this attendee to this session if unprocessed so far
		if ($current->processed == 0) {		
			//use their existing study group as a starting point, if already defined
			if ($current->session > 0) {
				$starting_session = $current->session;
			}
			else {
				$starting_session = $i;
			}
			
			//generate stats about this attendee
			$gender = $current->booking_gender == 'M' ? 'male' : 'female';		
			$age = _booking_get_age_years($current->booking_dob);
		
			if ($age < 20) {
				$age_type = 'under20';
			}
			elseif($age >= 20 && $age < 25) {
				$age_type = '20to25';
			}
			else {
				$age_type = 'over25';
			}
			
			//make sure this person is going to fit in with our calculated gender ratios
			_booking_loop_carefully($session_count, $gender, $starting_session, $maximums[$gender], $group->booking_num_group_sessions, 3, $calculation_messages);		
			//make sure this person is going to fit in with our calculated age ratios
			_booking_loop_carefully($session_count, $age_type, $starting_session, $maximums[$age_type], $group->booking_num_group_sessions, 3, $calculation_messages);
			//check for maximum group size
			_booking_loop_carefully($session_count, 'total', $starting_session, $max_people, $group->booking_num_group_sessions, 4, $calculation_messages);	
			
			$calculation_messages[] = t('Assigning person !name with id !id with gender !gender and age group !age to session !session (currently with !num people).', 
				array('!name' => $current->booking_firstname . ' ' . $current->booking_lastname,
				'!id' => $iterator->key(), '!session' => $starting_session, 
				'!num' => $session_count[$starting_session]['total'], '!gender' => $gender, '!age' => $age_type )
			);
			_booking_assign_attendee_group($iterator->key(), $starting_session, $gender, $age, $working_list, $session_count, $calculation_messages);				

		}	//end processed check

		//move to the next unprocessed attendee in the list
		while ($iterator->valid() && $iterator->current()->processed == 1) {
			//drupal_set_message(t("Skipping attendee ID !id, already processed.", array('!id' => $iterator->key())));
			$iterator->next();
		}
	
		//move to the next session
		$i++;	
	}	//finished looping through attendees for this study group	
}

/**
 * Process the submission to accept calculated study group membership updates
 */
function booking_studygroups_update_form_submit($form, &$form_state) {
	global $event;
	$values = $form_state['input'];	

	$raw_updates = unserialize($values['update_string']);
	$raw_inserts = unserialize($values['insert_string']);
	watchdog('booking', "<pre>Study group insert confirmation array:\n@info</pre>", array('@info' => print_r( $raw_inserts, true)));
	watchdog('booking', "<pre>Study group update confirmation array:\n@info</pre>", array('@info' => print_r( $raw_updates, true)));

	//process the updates
	foreach($raw_updates as $update)
	{
		$rows = db_update('booking_studygroup_mapping')
		  ->fields($update['fields'])
		  ->condition('sid', $update['sid'])
		  ->execute();
		//watchdog('booking', "Updated sid !sid affecting !rows rows.", array('!sid' => $update['sid'], '!rows' => $rows));		
	}	

	//process the inserts using the multi-insert query type at https://drupal.org/node/310079
	$insert_query = db_insert('booking_studygroup_mapping')->fields(array('booking_eventid', 'booking_node_id', 
						'booking_studygroup_id', 'booking_session_id', 'booking_studygroup_role'));	
	
	foreach($raw_inserts as $insert)
	{
		$insert_query->values($insert);
	}
	$insert_query->execute();

	drupal_set_message(t('Study group update confirmation processed.'));
	//redirect the user back to the study groups page
	$form_state['redirect'] = array('admin/booking/studygroups');				
		
}


/**
 * Function for viewing a printable format of who belongs to which study group
 */
function booking_studygroups_printview_form($node, &$form_state, $group_id) {
	global $event;
	
	$form = array();	
	$rows = array();
	$last_session = "";
	
	/*
	//attach the custom css
	$form['#attached']['css'] = array(
	  drupal_get_path('module', 'booking') . '/booking.css',
	);	
	*/
	
	
	//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/config/booking');
		return "";
	}
	
	//collect information on the study group
	$group = db_query("SELECT * FROM {booking_studygroup_list} WHERE booking_eventid = :eid and sid = :sid",
						array(':eid' => $event->eid, ':sid' => $group_id))
			->fetchObject();	
			
	if (! $group)
	{
		drupal_set_message("Error: Could not find matching study group ID. Unable to view group membership.", 'error', FALSE);
		drupal_goto('admin/config/booking');
		return "";			
	}

	$header = array(
		'booking_session_id' => array('data' => t('Study Group Session'), 'field' => 'm.booking_session_id'),		
		'booking_name' => array('data' => t('Name'), 'field' => 'p.booking_lastname', 'sort' => 'asc'),
		'booking_mobilenum' => array('data' => t('Mobile Number'), 'field' => 'p.booking_mobile'),
		'booking_email' => array('data' => t('Email'), 'field' => 'p.booking_email'),
		'booking_studygroup_role' => array('data' => t('Role')),
	);	
	
	$query = db_select('booking_person', 'p');
	$query->leftJoin('booking_studygroup_mapping', 'm', 'm.booking_node_id = p.nid');
	$db_and = db_and();
	$db_and->condition('p.booking_eventid', $event->eid, '=');
	$db_and->condition('m.booking_studygroup_id', $group_id, '=');
	$query->condition($db_and);
	$query->fields('p')->fields('m');
	$table_sort = $query->extend('TableSort')->orderbyHeader($header);
	$result = $table_sort->execute();					
	
	//$result = $query->execute();	

	//watchdog('booking', 'Study groups raw data: @info', array ('@info' => var_export($result, TRUE)));

	foreach($result as $data)
	{
		$class = "";
		$role = "";
		
		//apply theme as required
		if ($data->booking_is_leader == 'Y')
		{
			$class = "leader-row";
			$role = "Leader";
		}
		elseif ($data->booking_is_helper == 'Y')
		{
			$class = "helper-row";
			$role = "Helper";
		}
		elseif ($data->booking_is_reserveleader == 'Y')
		{
			$class = "helper-row";	
			$role = "Reserve Leader";
		}		
		else
			$class = "normal-row";	

		$rows[] = array (
			'data' => array(
				$data->booking_session_id,
				$data->booking_firstname . " " . $data->booking_lastname,
				$data->booking_mobile,
				$data->booking_email,
				$role,
			),
			'class' => array($class),
		);
	}	
	
	$prefix = t("<h2>Study Group !descrip</h2>", array('!descrip' => $group->booking_studygroup_descrip));

/*
	$form['table'] = array (
		'#type' => 'tableselect',
		'#header' => $header,
		'#options' => $options,
		//'#attributes' => array('id' => 'sort-table'),
	);
*/
	$result = array (
		'first_para' => array (
			'#type' => 'markup',
			'#markup' => $prefix,
		),
		'table' => array (
		  '#theme' => 'table',
		  '#header' => $header,
		  '#rows' => $rows,
		  '#attributes' => array('id' => 'sort-table'),		
		  //'#sticky' => FALSE,
		)
	);	
	watchdog('booking', "<pre>Group printable format:\n@info</pre>", array('@info' => print_r( $result, true)));
	
	return $result;
}

/**
 * Function for viewing who belongs to which study group
 */
function booking_studygroups_view_form($node, &$form_state, $group_id) {
	global $event;
	//$is_reading_group = FALSE;
	$form = array();	
	$options = array();
	$rows = array();
	$last_session = "";
	$class_array = array(
		0 => "normal-row",
		1 => "leader-row",
		2 => "helper-row",
		3 => "reserveleader-row",
		4 => "reservehelper-row",		
	);

	//attach the custom css
	/*
	$form['#attached']['css'] = array(
	  drupal_get_path('module', 'booking') . '/booking.css',
	);
	*/
	//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/config/booking');
		return "";
	}
	
	//collect information on the study group
	$group = db_query("SELECT * FROM {booking_studygroup_list} WHERE booking_eventid = :eid and sid = :sid",
						array(':eid' => $event->eid, ':sid' => $group_id))
			->fetchObject();	
			
	if (! $group) {
		drupal_set_message("Error: Could not find matching study group ID. Unable to view group membership.", 'error', FALSE);
		drupal_goto('admin/config/booking');
		return "";			
	}

	$header = array(
		'booking_session_id' => array('data' => t('Study Group Session'), 'field' => 'm.booking_session_id', 'sort' => 'asc'),		
		'booking_name' => array('data' => t('Name'), 'field' => 'p.booking_lastname'),
		'booking_gender' => array('data' => t('Gender'), 'field' => 'p.booking_gender'),
		'booking_age' => array('data' => t('Age'), 'field' => 'p.booking_dob'),
		'booking_baptised' => array('data' => t('Baptised?'), 'field' => 'p.booking_baptised'),
		'booking_married' => array('data' => t('Married?'), 'field' => 'p.booking_married'),
		'booking_phone' => array('data' => t('Phone Number'), 'field' => 'p.booking_mobile'),		
		//'booking_status' => array('data' => t('Booking Status'), 'field' => 'p.booking_status'),
		'booking_studygroup_role' => array('data' => t('Studygroup Role'), 'field' => 'p.booking_studygroup_role'),
		'booking_committee' => array('data' => t('Committee Member?'), 'field' => 'p.booking_committee_member'),
		'booking_session_manually_allocated' => array('data' => t('Manually Assigned?'), 'field' => 'm.booking_session_manually_allocated'),
	);	
	
	if ($group->booking_is_readinggroup == 'Y') {
		$header['booking_session_id']['data'] = t('Team Colour');				
	} 
	
	$query = db_select('booking_person', 'p');
	$query->leftJoin('booking_studygroup_mapping', 'm', 'm.booking_node_id = p.nid');
	
	$db_and = db_and();
	$db_and->condition('p.booking_eventid', $event->eid, '=');
	$db_and->condition('m.booking_studygroup_id', $group_id, '=');
	
	$query->condition($db_and);
	$query->fields('p')->fields('m');
	
	$table_sort = $query->extend('TableSort')->orderbyHeader($header);
	$result = $table_sort->execute();	

	//watchdog('booking', 'Study groups raw data: @info', array ('@info' => var_export($result, TRUE)));
	
	//retrieve which sort is active in the current view
	$sort = tablesort_get_order($header);
	$last_session = 0;

	foreach($result as $data)
	{
		//apply theme as required		
		$class = $class_array[$data->booking_studygroup_role];

		//only add the lines separating groups if we're sorting by the session id
		if ($sort['sql'] == "m.booking_session_id") {
			//Add a different id for first entry of new session, with a border-top to distinguish it
			if ($last_session <> $data->booking_session_id) {
				switch ($data->booking_studygroup_role) {
					case 1:
						$class = "leader-new-group-row";
						break;
					case 2:
						$class = "helper-new-group-row";
						break;
					case 3:
						$class = "reserveleader-new-group-row";
						break;
					case 4:
						$class = "reservehelper-new-group-row";
						break;						
					default:
						$class = "new-group-row";
						
				}
			}
		}	//end class calculation
		
		$session = $group->booking_is_readinggroup == 'Y' ? _booking_readinggroup_colour_lookup($data->booking_session_id) : $data->booking_session_id;

		$rows[] = array(
			'data' => array(			
				$session,
				l(t('!first !last', array('!first' => $data->booking_firstname, '!last' => $data->booking_lastname)),  
					t('admin/booking/!id/edit-studygroup-membership', array('!id' => $data->nid))),
				//_booking_status_generate($data->booking_status),
				$data->booking_gender == 'M' ? 'Male' : 'Female',
				_booking_get_age_years($data->booking_dob),
				$data->booking_baptised == 'Y' ? 'Yes' : 'No',	
				$data->booking_married == 'Y' ? 'Yes' : 'No',
				$data->booking_mobile,							
				_booking_studygroup_role_lookup($data->booking_studygroup_role),
				$data->booking_committee_member == 'Y' ? 'Yes' : 'No',
				$data->booking_session_manually_allocated == 'Y' ? 'Yes' : 'No',
			),
			'id' => array($class),
		);		
		
		$last_session = $data->booking_session_id;
	}	
	
	$prefix = t("<h2>Study Group !descrip</h2>", array('!descrip' => $group->booking_studygroup_descrip));
	return array (
		'#attached' => array (
			'css' => array(drupal_get_path('module', 'booking') . '/booking.css')
		),	
		'first_para' => array (
			'#type' => 'markup',
			'#markup' => $prefix,
		),
		'table' => array (
		  '#theme' => 'table',
		  '#header' => $header,
		  '#rows' => $rows,
		  '#attributes' => array('id' => 'sort-table'),		
		  //'#sticky' => FALSE,
		)	
	);	
}


/**
 * Function for updating the reading group colour based on the id automatically generated for them
 */
function booking_studygroups_process_colours() {
	global $event;

	//Query for all groups with the reading group flag set to Y, and loop through them all
	$query = db_select('booking_studygroup_mapping', 'm');
	$query->join('booking_studygroup_list', 's', 's.sid = m.booking_studygroup_id');
	$query->condition('s.booking_is_readinggroup', 'Y', '=');
	$query->fields('m')->fields('s', array('booking_studygroup_descrip'));
	$group_mapping = $query->execute()->fetchAllAssoc('sid');			
	
	foreach ($group_mapping as $mapping)
	{
		$colour = _booking_readinggroup_colour_lookup($mapping->booking_session_id);
		
		//drupal_set_message(t('Updating user !id to be in team !colour.', 
		//	array('!id' => $mapping->booking_node_id, '!colour' => $colour)));
		
		//run an update query
		db_update('booking_person')
		->fields(array (
			'booking_readinggroup' => $colour,
			))
		->condition('nid', $mapping->booking_node_id)
		->execute();		
	}
	drupal_set_message(t('Updated reading group colours'));
}