<?php

/**
 * @file
 * Admin pages for configuring a variety session
 * NOTE: This feature is not complete and probably never will be
 */

function booking_variety_admin() {
  global $event;
  //see http://www.jaypan.com/blog/themeing-drupal-7-forms-tables-checkboxes-or-radios	
  // tableselect with text fields http://drupal.stackexchange.com/questions/75950/tableselect-with-textfields/82763#82763
  // inline edit buttons http://drupal.stackexchange.com/questions/31942/how-do-i-add-an-edit-button-on-each-row-of-a-tableselect-form-element
  // tabledrag example http://dropbucket.org/node/204
  $form = array ();	
  $options = array ();
  $result = db_query("SELECT * from {booking_variety_timeslots}");

  $header = array (
    'eid' => t('Event'),
    'tid' => t('Timeslot ID'),
    'booking_variety_time_descrip' => t('Description'),
    'booking_variety_status' => t('Status'),
    'booking_variety_start' => t('Timeslot Start'),
    'booking_variety_end' => t('Timeslot End'),
    'variety_edit'	=> t('Edit Timeslot'),
    'variety_session_list' => t('List Sessions'),
    'variety_session_add'	=> t('Add Session'),
    'variety_session_csv' => t('CSV Report'),
  );	

  foreach($result as $data) {
    $options[$data->tid] = array (
      'eid' => $event->booking_eventname,
      'tid' => $data->tid,
      'booking_variety_time_descrip' => $data->booking_variety_time_descrip,
      'booking_variety_status' => $data->booking_variety_status == 1 ? "Enabled" : "Disabled",
      'booking_variety_start' => date("Y-m-d H:i", $data->booking_variety_start),
      'booking_variety_end' => date("Y-m-d H:i", $data->booking_variety_end),			
      'variety_edit' => l('Edit Timeslot', t('admin/booking/variety/!tid/edit', array('!tid' => $data->tid))),
      'variety_session_list' => l('List Sessions', t('admin/booking/variety/!tid/session/list', array('!tid' => $data->tid))),
      'variety_session_add' => l('Add Session', t('admin/booking/variety/!tid/session/create', array('!tid' => $data->tid))),
      'variety_session_csv' => l('CSV Report', t('admin/booking/variety/!tid/csv', array('!tid' => $data->tid))),
    );
  }	
  
  $form['table'] = array (
    '#type' => 'tableselect',
    '#header' => $header,
    '#options' => $options,
    '#multiple' => false,
  );	

  return array (
    'form' => $form,
  );
}

/**
 * Function to add a new variety session timeslot
 */
function booking_variety_timeslot_form($node, &$form_state, $create, $editid = 0) {
  global $event;
  $form = array ();
  $prefix = "<p>Add a new variety session timeslot for the bookings module.</p>";
  
  if ($create == true) {
    $data = $node;
  }
  else {
    //verify that $editid is a number
    if (! preg_match('/^[0-9]+$/', $editid)) {
      drupal_set_message("Error: Invalid variety ID supplied. Unable to update variety session information.", 'error', FALSE);
      drupal_goto('admin/booking/variety');
      return "";
    }		
    
    $data = db_select ('booking_variety_timeslots', 'v')
      ->condition('v.tid', $editid, '=')
      ->fields('v')
      ->execute()
      ->fetchObject();		
        
    $prefix = t("<p>Update the !event variety session details.</p>", array('!event' => $event->booking_eventname));
    //add this to the form in a hidden field so we can update the right event
    $form['tid'] = array (
      '#type' => 'hidden',
      '#value' => $editid,
    );					
  }

  $form['booking_variety_time_descrip'] = array (
    '#type' => 'textfield',
    '#title' => t('The name of this variety session timeslot'),
    '#size' => 60,	
    '#maxlength' => 150,
    '#required' => TRUE,
    '#default_value' => !empty($data->booking_variety_time_descrip) ? $data->booking_variety_time_descrip : '',
  );	

  $form['booking_variety_status'] = array(
    '#type' => 'checkbox',
    '#title' => t('Make this variety session timeslot active'),
    '#default_value' => !empty($data->booking_variety_status) ? $data->booking_variety_status : '',
  );
  
   $form['booking_variety_start'] = array(
    '#type' => 'date_select',
    '#title' => t('When will this variety session start'),
    '#default_value' => empty($data->booking_variety_start) ? date("Y-m-d H:i:s") : date("Y-m-d H:i:s", $data->booking_variety_start),
    '#date_format' => 'd/m/Y H:i',
    '#date_label_position' => 'within',
    '#date_year_range' => '0:+5'
  );	

   $form['booking_variety_end'] = array(
    '#type' => 'date_select',
    '#title' => t('When will this variety session end?'),
    '#default_value' => empty($data->booking_variety_end) ? date("Y-m-d H:i:s") : date("Y-m-d H:i:s", $data->booking_variety_end),
    '#date_format' => 'd/m/Y H:i',
    '#date_label_position' => 'within',
    '#date_year_range' => '0:+5'
  );	

  if ($create == true) {
    $form['submit'] = array (
      '#type' => 'submit',
      '#value' => t('Create'),
    );	
  } 
  else {
    $form['Update'] = array (
      '#type' => 'submit',
      '#value' => t('Update'),
    );
    $form['Delete'] = array (
      '#type' => 'submit',
      '#value' => t('Delete'),
    );		
  }		
  
  return array(
    'first_para' => array (
      '#type' => 'markup',
      '#markup' => $prefix,
    ),
    'form' => $form,
  );
}

/**
 * Function to submit data for a new variety session timeslot
 */
function booking_variety_timeslot_form_submit($form, &$form_state) {
   global $event;
  $values = $form_state['input'];

  if ($form_state['values']['op'] == 'Create') {							
    db_insert('booking_variety_timeslots')
      ->fields(array(	
          'booking_eventid' => $event->eid,
          'booking_variety_status' => $values['booking_variety_status'] == 1 ? 1 : 0,
          'booking_variety_time_descrip' => $values['booking_variety_time_descrip'],			
        'booking_variety_start' => _datetime_array_to_ts($values['booking_variety_start']),
        'booking_variety_end' => _datetime_array_to_ts($values['booking_variety_end']),
      ))
      ->execute();		
  }
  elseif ($form_state['values']['op'] == 'Delete') {
    //verify that tid is a number
    if (! preg_match('/^[0-9]+$/', $values['tid'])) {
      drupal_set_message("Error: Invalid variety timeslot ID supplied. Unable to delete entry.", 'error', FALSE);
      return "";
    }		

    $num_deleted = db_delete('booking_variety_timeslots')
      ->condition('tid', $values['tid'])
      ->execute();	

    $message = t("Successfully deleted !num row(s), corresponding to variety session timeslot '!desc'", 
          array('!num' => $num_deleted, '!desc' => $values['booking_variety_time_descrip']));
    drupal_set_message($message, $type = 'status');					
  } 
  else {
    //verify that booking_eid is a number
    if (! preg_match('/^[0-9]+$/', $values['tid'])) {
      drupal_set_message("Error: Invalid variety session timeslot ID supplied. Unable to update entry.", 'error', FALSE);
      return "";
    }
    
    //update the event
    db_update('booking_variety_timeslots')
    ->fields(array (
      'booking_eventid' => $event->eid,		
      'booking_variety_time_descrip' => $values['booking_variety_time_descrip'],
      'booking_variety_status' => $values['booking_variety_status'] == 1 ? 1 : 0,	
      'booking_variety_start' => _datetime_array_to_ts($values['booking_variety_start']),
      'booking_variety_end' => _datetime_array_to_ts($values['booking_variety_end']),
      ))
    ->condition('tid', $values['tid'])
    ->execute();					
  }
  
  $form_state['redirect'] = array('admin/booking/variety');	
}

/**
 * Function to create or edit a variety session
 */
function booking_variety_create_session_form($node, &$form_state, $create = TRUE, $timeslot_id = 0, $session_id = 0) {
  global $event;
  $form = array ();
  $prefix = "";

  //add this to the form in a hidden field so we can update the right event
  $form['tid'] = array (
    '#type' => 'hidden',
    '#value' => $timeslot_id,
  );  
  
  if ($create == TRUE) {
    $data = $node;
    $prefix = "<p>Add a new variety session to the specified variety session timeslot for the bookings module.</p>";
  }
  else {
		//verify that $timeslot_id is a number
		if (! preg_match('/^[0-9]+$/', $timeslot_id)) {
			drupal_set_message("Error: Invalid timeslot ID supplied. Unable to update specified variety session.", 'error', FALSE);
			drupal_goto('admin/booking/variety');
			return "";
		}    
		//verify that $session_id is a number
		if (! preg_match('/^[0-9]+$/', $session_id)) {
			drupal_set_message("Error: Invalid session ID supplied. Unable to update specified variety session.", 'error', FALSE);
			drupal_goto('admin/booking/variety');
			return "";
		}
    $prefix = t("<p>Update the variety session defintion.</p>");
		$data = db_query("SELECT * FROM {booking_variety_sessions} WHERE vid = :id", array(':id' => $session_id))
        ->fetchObject();
        
		//add this to the form in a hidden field so we can update the right variety session
		$form['booking_session_id'] = array(
			'#type' => 'hidden',
			'#value' => $session_id,
		);        
  }

	//define the form for variety session configuration if we're not deleting a session
	if(!isset($form_state['storage']['confirm'])) {
		$form[] = array (
			'first_heading' => array(
				'#type' => 'markup',
				'#markup' => $prefix,
			),
    );

    $form['booking_variety_descrip'] = array (
      '#type' => 'textfield',
      '#title' => t('The name of the variety session to add to this timeslot'),
      '#size' => 60,	
      '#maxlength' => 150,
      '#required' => TRUE,
      '#default_value' => !empty($data->booking_variety_descrip) ? $data->booking_variety_descrip : '',
    );	

    $form['booking_variety_status'] = array(
      '#type' => 'checkbox',
      '#title' => t('Make this variety session active?'),
      '#default_value' => !empty($data->booking_variety_status) ? $data->booking_variety_status : '',
    );
    
    $form['booking_variety_maxsize'] = array (
      '#type' => 'textfield',
      '#title' => t('The maximum number of people permitted in this variety session'),
      '#size' => 5,	
      '#maxlength' => 5,
      '#required' => TRUE,
      '#default_value' => !empty($data->booking_variety_maxsize) ? $data->booking_variety_maxsize : '0',
    );	

    if ($create == true) {
      $form['submit'] = array(
        '#type' => 'submit',
        '#value' => t('Create Session'),
      );	
    } 
    else {
      $form['Update'] = array(
        '#type' => 'submit',
        '#value' => t('Update Session'),
      );
      $form['Delete'] = array(
        '#type' => 'submit',
        '#value' => t('Delete Session'),
      );		
    }  
    return array (
      'form' => $form,
    );
  } //end checking for delete confirmation
  else {
    return confirm_form($form, "Are you sure you wish to delete variety session definition with id " . $session_id . "?", 
    current_path(), NULL, "Delete Session");		
  }
}

/**
 * Function submit data for a variety session timeslot
 */
function booking_variety_create_session_form_submit($form, &$form_state) {
  global $event;
  $values = $form_state['input'];
  $timeslot_id = $values['tid'];
  $redirect_path = "admin/booking/variety/$timeslot_id/session/list";

	//if we're deleting, add the confirmation to the form if it hasn't been defined yet
  if($form_state['values']['op'] == 'Delete Session' && (!isset($form_state['storage']['confirm']))) {
		//watchdog('booking_debug', "<pre>Variety session deletion confirmation being set:\n@info</pre>", array('@info' => print_r( $form_state, true)));
		$form_state['storage']['confirm'] = TRUE;
		$form_state['rebuild'] = TRUE;
  }
	elseif ($form_state['values']['op'] == 'Delete Session') {
		//delete the variety session
		watchdog('booking', "Deleting variety session ID !sid", array('!sid' => $values['booking_session_id']));

		db_delete('booking_variety_sessions')
			->condition('vid', $values['booking_session_id'])
		 	->execute();

    //TODO : Remove this variety session from anyone registered for it

		drupal_set_message('Deleted variety session id ' . $values['booking_session_id'] );
		$form_state['redirect'] = $redirect_path;
	}
	elseif ($form_state['values']['op'] == 'Update Session') {
		$result = db_update('booking_variety_sessions')
			->fields(array(
        'booking_eventid' => $event->eid,
        'booking_variety_descrip' => $values['booking_variety_descrip'],
        'booking_variety_status' => $values['booking_variety_status'] == 1 ? 1 : 0,
        'booking_variety_maxsize' => $values['booking_variety_maxsize'],
			))
			->condition('vid', $values['booking_session_id'] )
			->execute();
		drupal_set_message('Updated variety session id ' . $values['booking_session_id'] );
		$form_state['redirect'] = $redirect_path;
	}
	elseif ($form_state['values']['op'] == 'Create Session') {							
    db_insert('booking_variety_sessions')
      ->fields(array(	
        'booking_eventid' => $event->eid,
        'booking_variety_timeslot_id' => $values['tid'],
        'booking_variety_status' => $values['booking_variety_status'] == 1 ? 1 : 0,
        'booking_variety_descrip' => $values['booking_variety_descrip'],		
        'booking_variety_maxsize' => $values['booking_variety_maxsize'],
        'booking_variety_regncount' => 0,
      ))
      ->execute();
		drupal_set_message('Created new variety session definition');
		$form_state['redirect'] = $redirect_path;	
	}
}

/**
 * Function to list all variety sessions for specified timeslot
 */
function booking_variety_list_session_form($node, &$form_state, $timeslot_id = 0)
{
  global $event;
  $form = array ();
  $options = array ();
  $data = $node;

  //verify that $editid is a number
  if (! preg_match('/^[0-9]+$/', $timeslot_id)) {
    drupal_set_message("Error: Invalid variety ID supplied. Unable to select variety session information.", 'error', FALSE);
    drupal_goto('admin/booking/variety');
    return "";
  }		
  
  $prefix = t("<p>!link</p>",
        array ('!link' => l('Add New Variety Session', "admin/booking/variety/$timeslot_id/session/create")));	
  
  $query = db_select ('booking_variety_sessions', 'v');
  $query->join('booking_variety_timeslots', 't', 'v.booking_variety_timeslot_id = t.tid');
  $query->condition('v.booking_variety_timeslot_id', $timeslot_id, '=')
    ->fields('v')
    ->fields('t', array('booking_variety_time_descrip'));
  $result = $query->execute();	
  
  //watchdog('booking', 'Variety session query: @info', array ('@info' => (string)$query));
  
  $header = array (
    'variety_timeslot' => t('Variety Timeslot'),
    'booking_variety_descrip' => t('Variety Session Description'),
    'booking_variety_status' => t('Status'),
    'booking_variety_maxsize' => t('Maximum Capacity'),
    'booking_variety_regncount' => t('Current Registration Count'),
    'variety_edit'	=> t('Edit Session')
  );	
  
  foreach($result as $data) {
    $options[$data->vid] = array (
      'variety_timeslot' => $data->booking_variety_time_descrip,
      'booking_variety_descrip' => $data->booking_variety_descrip,
      'booking_variety_status' => $data->booking_variety_status == 1 ? 'Active' : 'Inactive',
      'booking_variety_maxsize' => $data->booking_variety_maxsize,
      'booking_variety_regncount' => $data->booking_variety_regncount,
      'variety_edit' => l('Edit Session', t('admin/booking/variety/!tid/session/!vid/edit', 
        array('!tid' => $timeslot_id, '!vid' => $data->vid))),
    );
  }	
  
  $form['table'] = array (
    '#type' => 'tableselect',
    '#header' => $header,
    '#options' => $options,
    '#multiple' => false,
  );	

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

/**
 * Function to generate table listing all variety session registrations
 */
function booking_variety_sessions_view_summary() {
	global $event;
	$output = "";
	$header = array('First Name', 'Last Name');
	$rows = array();
  $attributes = array('style' => 'max-width:100%');	

  //get variety session timeslot definitions
  $timeslot_query = db_select('booking_variety_timeslots', 't');	
  $timeslot_query->condition('t.booking_eventid', $event->eid, '=')
    ->fields('t')
    ->orderBy('t.booking_variety_start');
  $timeslot_list = $timeslot_query->execute()->fetchAllAssoc('tid'); 

  //watchdog('booking_debug', "<pre>Variety Session Report timeslots:\n@info</pre>", array('@info' => print_r( $timeslot_list, true)));

  //get vareity session definitions
  $sessions_query = db_query("SELECT * FROM {booking_variety_sessions} WHERE booking_eventid = :eid", 
    array(':eid' => $event->eid));
  $sessions = $sessions_query->fetchAllAssoc('vid');  

  //watchdog('booking_debug', "<pre>Variety Session Report sessions:\n@info</pre>", array('@info' => print_r( $sessions, true)));

  foreach ($timeslot_list as $timeslot) {
    $header[] = $timeslot->booking_variety_time_descrip;
  }
  // Add a link at the end to edit a variety session registration
  $header[] = "Edit Session Registrations";

  $person_query = db_query("SELECT * FROM {booking_person_view} WHERE booking_status = 1 " . 
                          " ORDER BY booking_lastname, booking_firstname")->fetchAllAssoc('nid');	  

  //loop through each matching person
  foreach ($person_query as $person) {
    //add the name to an array for this line
    $newline = array($person->booking_firstname, $person->booking_lastname);
    $session_ids = drupal_json_decode($person->booking_variety_ids);

    foreach ($timeslot_list as $timeslot) {
      if (isset($session_ids[$timeslot->tid])) {
        //get details of the person's variety session for this timeslot
        $vid = $session_ids[$timeslot->tid];

        //watchdog('booking_debug', 'Person @nid in timeslot @tid registered for session id @vid', array(
        //  '@nid' => $person->nid, '@tid' => $timeslot->tid, '@vid' => $vid,
        //));
        
        // in case the person is somehow registered for a session that no longer exists
        if (isset($sessions[$vid])) {
          $text = $sessions[$vid]->booking_variety_descrip;
        }
        else {
          $text = "";
        }
        $newline[] = $text;
      }
      else {
        $newline[] = "";        
      }
    } //end iterate variety session timeslot list
    $newline[] = l('Edit', t('admin/booking/variety/registration/!nid/edit', array('!nid' => $person->nid)));

    //add the line to the array of rows
    $rows[] = $newline;
  } //end iterate person list

	//output everything
  $output .= t("<h3>!event Variety Session Registrations</h3>", array('!event' => $event->booking_eventname));
	$output .= theme('table', array('header' => $header, 'rows' => $rows, 'attributes' => $attributes));

	return $output;
}

/**
 * Function to generate a CSV file listing the session membership for the specified variety session timeslot
 */
function booking_varietysessions_csv_report($timeslot_id) {
  global $event;
  $data = array();
  $rows = array();

  //include_once("./libraries/xlsxwriter.class.php");
  module_load_include('php', 'booking', 'libraries/xlsxwriter.class');

  //verify that $timeslot_id is a number
  if (! preg_match('/^[0-9]+$/', $timeslot_id)) {
    drupal_set_message("Error: Invalid variety session timeslot ID '" . $timeslot_id . "' supplied.", 'error', FALSE);
    drupal_goto('admin/booking/variety');
    return "";
  }  	

  //retrieve the sessions for the specified timeslot
  $db_and = db_and();
  $db_and->condition('v.booking_eventid', $event->eid, '=');
  $db_and->condition('v.booking_variety_timeslot_id', $timeslot_id, '=');
  $variety_sessions = db_select('booking_variety_sessions', 'v')
    ->condition($db_and)
    ->fields('v')
    ->execute()
    ->fetchAllAssoc('vid');

  //watchdog('booking_debug', 'booking_varietysessions_csv_report variety sessions: <pre>@info</pre>', array('@info' => print_r( $variety_sessions, true)));
  if (! $variety_sessions) {
    drupal_set_message("Error: Could not find matching variety session timeslot. Unable to view session membership.", 'error', FALSE);
    drupal_goto('admin/booking/variety');
    return "";			
  }  
  
  //set options for the CSV file
  $csv = '';
  $delimiter = ',';
  $enclosure = '"';
  $encloseAll = false;
  $nullToMysqlNull = true;
  $delimiter_esc = preg_quote($delimiter, '/');
  $enclosure_esc = preg_quote($enclosure, '/');

  //get the list of variety session memberships
  $session_members_query = db_query("SELECT r.*, p.* FROM {booking_variety_regn} r
    inner join {booking_person} p on p.nid = r.booking_person_nid
    WHERE p.booking_eventid = :eid ORDER BY r.rid", 
    array(':eid' => $event->eid));
  $session_members = $session_members_query->fetchAll();

  // Check if we had no data added, that means there were no people in this study group
  if (! $session_members) {
    drupal_set_message("Error: Variety Session timeslot $timeslot_id has no members assigned.", 'error', FALSE);
		drupal_goto('admin/booking/variety');    
		return "";
  }    
  
  //watchdog('booking_debug', 'booking_varietysessions_csv_report session members: <pre>@info</pre>', array('@info' => print_r( $session_members, true)));
  
  // Organise people by session ID
  foreach ($session_members as $member) {
    $session_ids = drupal_json_decode($member->booking_variety_ids);
    //watchdog('booking_debug', 'booking_varietysessions_csv_report person session ids: <pre>@info</pre>', array('@info' => print_r( $session_ids, true)));

    //get the session id that matches our timeslot
    $sid = $session_ids[$timeslot_id];

    if (! isset($data[$sid])) {
      $data[$sid] = array();
    }
    $text = array($member->booking_firstname, $member->booking_lastname);

    //add the spaces and put this element in the right array
    $data[$sid][] = implode(' ', $text);

  }
  //watchdog('booking_debug', "<pre>Study Group CSV Report\n@info</pre>", array('@info' => print_r( $data_array, true)));
  
  // Calculate column headings and spreadsheet layout
  $header_array = array_keys($data);
  $maximums = array();
  $column_headings = array();
  foreach ($header_array as $column) {
    $maximums[] = count($data[$column]);
    //make the column headings a bit more user friendly
    $heading = $variety_sessions[$column]->booking_variety_descrip;
    //enclose $heading if necessary
    if ( $encloseAll || preg_match( "/(?:${delimiter_esc}|${enclosure_esc}|\s)/", $heading ) ) {
      $heading = $enclosure . str_replace($enclosure, $enclosure . $enclosure, $heading) . $enclosure;
    }

    // Adjusted for excel, assume each column is just a string
    $column_headings[] = array($heading => 'string');
  }
  
 watchdog('booking_debug', "<pre>Variety session spreadsheet columns\n@info</pre>", 
  array('@info' => print_r( $column_headings, true)));
  

  // Calculate each row based on column headings
  for ($i = 0; $i < max($maximums); $i++) {
    $output = array();
    foreach ($header_array as $column) {
      $field = isset($data[$column][$i]) ? $data[$column][$i] : '';

      //enclose $field if necessary
      if ( $encloseAll || preg_match( "/(?:${delimiter_esc}|${enclosure_esc}|\s)/", $field ) ) {
        $output[] = $enclosure . str_replace($enclosure, $enclosure . $enclosure, $field) . $enclosure;
      }
      else {
        $output[] = $field;
      }
    } //loop through columns
    $rows[] = $output;
    //$row = implode($delimiter, $output) . "\n";
    //$csv .= $row;
    
  }

  // Create headers for Excel spreadsheet
  $filename = 'bookings-timeslot-' . $timeslot_id . '-variety-sessions-' . format_date(time(), 'custom', 'Y-m-d-His') . ".xlsx";
  header('Content-disposition: attachment; filename="'.XLSXWriter::sanitize_filename($filename).'"');
  header("Content-Type: application/vnd.openxmlformats-officedocument.spreadsheetml.sheet");
  header('Content-Transfer-Encoding: binary');
  header('Cache-Control: must-revalidate');
  header('Pragma: public');

  $sheetname = "Variety Session " . $timeslot_id;
  $writer = new XLSXWriter();
  $writer->setAuthor($event->booking_eventname); 
  //Add the header row
  $writer->writeSheetHeader($sheetname, $column_headings);

  //Add the data
  foreach($rows as $row) {
    $writer->writeSheetRow($sheetname, $row);
  }

  $writer->writeToStdOut();
  exit(0);  
}

/**
 * Build the admin form for editing variety session registrations
 */
function booking_variety_regn_edit_form($node, &$form_state, $nid)
{
  global $event;
  $form = array();
  $data = $node;
  $redirect_path = "admin/booking/variety/report";

  //verify that $variety_regn_id is a number
  if (! preg_match('/^[0-9]+$/', $nid)) {
    drupal_set_message("Error: Invalid variety session registration ID supplied. Unable to update variety session registration for user.", 'error', FALSE);
    drupal_goto($redirect_path);
    return "";
  }

  $person = db_query("SELECT * FROM {booking_person_view} WHERE nid = :nid",
    array(':nid' => $nid))->fetchObject();	    

  if (! $person) {
    drupal_set_message("Error: Could not find matching person. Unable to edit variety session registrations.", 'error', FALSE);
    drupal_goto($redirect_path);
    return "";			    
  }
  $session_ids = drupal_json_decode($person->booking_variety_ids);
	$prefix = t("<h3>Edit variety session registration for !first !last.<br /></h3>", 
		array('!first' => $person->booking_firstname, '!last' => $person->booking_lastname));	  

  // Query the variety timeslot table so we know how many select elements to create
  $timeslot_query = db_select('booking_variety_timeslots', 'v');	
  $timeslot_query->condition('v.booking_eventid', $event->eid, '=')
    ->fields('v')
    ->orderBy('v.booking_variety_start');
  $timeslot_result = $timeslot_query->execute();  

  // --- Form starts here ---
  //add the person nid to the form in a hidden field so we can update the right person later
  $form['nid'] = array (
    '#type' => 'hidden',
    '#value' => $nid,
  );

	//define the form for variety session configuration if we're not deleting a session
	if(!isset($form_state['storage']['confirm'])) {
		$form[] = array (
			'first_heading' => array(
				'#type' => 'markup',
				'#markup' => $prefix,
			),
    );
  
    $form['variety-sessions'] = array(
      '#type' => 'fieldset',
      '#title' => 'Select Variety Sessions',
      '#prefix' => '<div id="booking_variety_session_fieldset_wrapper">',
      '#suffix' => '</div>'
    );      

    //for each entry in the variety timeslot table, create a new form select item
    foreach($timeslot_result as $timeslot) {
      $fieldname = 'select-variety-' . $timeslot->tid;
      $default = isset($session_ids[$timeslot->tid]) ? $session_ids[$timeslot->tid] : '--';
      $default_value = isset($form_state['values'][$fieldname]) ? $form_state['values'][$fieldname] : $default;

      //create the form element for this timeslot
      $form['variety-sessions'][$fieldname] = array(
        '#type' => 'select',
        '#title' => t('Variety Session: ' . $timeslot->booking_variety_time_descrip),
        '#required' => TRUE,
        '#default_value' => $default_value,
        '#options' => _booking_get_variety_timeslot_options($timeslot->tid),        
      );
    }		

    $form['Update'] = array(
      '#type' => 'submit',
      '#value' => t('Update Session Registration'),
    );
    $form['Delete'] = array(
      '#type' => 'submit',
      '#value' => t('Delete Session Registration'),
    );		
 
    return array (
      'form' => $form,
    );
  } //end checking for delete confirmation
  else {
    return confirm_form($form, "Are you sure you wish to delete all variety session registrations for person id  " . $nid . "?", 
    current_path(), NULL, "Delete Session Registration");		
  }  
}

/**
 * Function submit data for editing a variety session registration for a person
 */
function booking_variety_regn_edit_form_submit($form, &$form_state) {
  global $event;
  $values = $form_state['input'];
  $booking_variety_ids = array();  
  $redirect_path = "admin/booking/variety/report";

  //get a list of timeslot IDs from matching form values
  $variety_timeslot_ids = preg_filter('/^select-variety-(\d+)/', '$1', array_keys( $values ));
  //build an associative array based on selections
  foreach ($variety_timeslot_ids as $id) {
    $selected_session_id = $values['select-variety-' . $id];
    // Don't try and check availablity for a select element that is still on the default value
    if ($selected_session_id == 0) {
      continue;
    }
    //store the selected variety sessions in an array of IDs
    $booking_variety_ids[$id] = $selected_session_id;
  }  
  watchdog('booking_debug', "<pre>Variety session IDs from edit form:\n@info</pre>", array('@info' => print_r( $booking_variety_ids, true)));

  // Get the previous variety session IDs so we can check for changes
  $person = db_query("SELECT * FROM {booking_person_view} WHERE nid = :nid",
    array(':nid' => $values['nid']))->fetchObject();    
  $previous_variety_ids = drupal_json_decode($person->booking_variety_ids);  

	//if we're deleting, add the confirmation to the form if it hasn't been defined yet
  if($form_state['values']['op'] == 'Delete Session Registration' && (!isset($form_state['storage']['confirm']))) {
		//watchdog('booking_debug', "<pre>Variety session registration deletion confirmation being set:\n@info</pre>", array('@info' => print_r( $form_state, true)));
		$form_state['storage']['confirm'] = TRUE;
		$form_state['rebuild'] = TRUE;
  }
	elseif ($form_state['values']['op'] == 'Delete Session Registration') {
		//delete the variety session
		watchdog('booking', "Deleting variety session registration for person ID !nid", array('!nid' => $values['nid']));
     
    //decremement regn count for this person's variety sessions
    foreach ($previous_variety_ids as $previous_tid => $previous_sid) {
      watchdog('booking_debug', 'Person @nid in timeslot @tid is no longer registered for any variety sessions so reducing count for @vid by 1', array(
        '@nid' => $values['nid'], '@tid' => $previous_tid, '@vid' => $previous_sid,
      ));
      // reduce regn count for old session
      db_update('booking_variety_sessions')
        ->expression('booking_variety_regncount', 'booking_variety_regncount - :count', array(':count' => 1))
        ->condition('vid', $previous_sid)
        ->execute();
    }      

    //delete this person's entry in the session registration table
		db_delete('booking_variety_regn')
			->condition('booking_person_nid', $values['nid'])
       ->execute();

		drupal_set_message('Deleted variety session registration for person id ' . $values['nid'] );
		$form_state['redirect'] = $redirect_path;
	}
	elseif ($form_state['values']['op'] == 'Update Session Registration') {
    // iterate over the new list comparing to the old list
    foreach ($booking_variety_ids as $new_tid => $new_sid) {
      //check if there was a previous session ID for this person in this timeslot
      if (! isset($previous_variety_ids[$new_tid])) {
        watchdog('booking_debug', 'Person @nid in timeslot @tid had no previous session id registered but is now @new.', array(
          '@nid' => $values['nid'], '@tid' => $new_tid, '@new' => $new_sid));
          
        // increase regn count for new session                               
        db_update('booking_variety_sessions')
          ->expression('booking_variety_regncount', 'booking_variety_regncount + :count', array(':count' => 1))
          ->condition('vid', $new_sid)
          ->execute();          
      }
      else {
        $previous_sid = $previous_variety_ids[$new_tid];
        //compare session id in this timeslot to the previous value
        if ($new_sid != $previous_sid) {
          watchdog('booking_debug', 'Person @nid in timeslot @tid previously registered for session id @vid but new value is @new', array(
            '@nid' => $values['nid'], '@tid' => $new_tid, '@vid' => $previous_sid, '@new' => $new_sid)); 

          // if variety session has changed then update the counts for old and new
          if ($new_sid != $previous_sid) {
            // reduce regn count for old session          
            watchdog('booking_debug', 'Person @nid in timeslot @tid is no longer registered for variety session @vid so reducing count by 1', array(
              '@nid' => $values['nid'], '@tid' => $new_tid, '@vid' => $previous_sid));
            db_update('booking_variety_sessions')
              ->expression('booking_variety_regncount', 'booking_variety_regncount - :count', array(':count' => 1))
              ->condition('vid', $previous_sid)
              ->execute();  

            // increase regn count for new session            
            watchdog('booking_debug', 'Person @nid in timeslot @tid is now registered for variety session @vid so increasing count by 1', array(
              '@nid' => $values['nid'], '@tid' => $new_tid, '@vid' => $new_sid));        
            db_update('booking_variety_sessions')
              ->expression('booking_variety_regncount', 'booking_variety_regncount + :count', array(':count' => 1))
              ->condition('vid', $new_sid)
              ->execute();            
          }
        }
        else {
          watchdog('booking_debug', 'Person @nid in timeslot @tid has not changed variety session @vid', array(
            '@nid' => $values['nid'], '@tid' => $new_tid, '@vid' => $new_sid));              
        }
      }
    }

    //iterate over the old list comparing to the new list in case there are regn counts we need to decrease
    if (isset($previous_variety_ids)) {
      foreach ($previous_variety_ids as $previous_tid => $previous_sid) {
        if (! isset($booking_variety_ids[$previous_tid])) {
          watchdog('booking_debug', 'Person @nid in timeslot @tid is no longer registered for a variety session so reducing count for @vid by 1', array(
            '@nid' => $values['nid'], '@tid' => $previous_tid, '@vid' => $previous_sid,
          ));
          // reduce regn count for old session
          db_update('booking_variety_sessions')
            ->expression('booking_variety_regncount', 'booking_variety_regncount - :count', array(':count' => 1))
            ->condition('vid', $previous_sid)
            ->execute();          
        }
      }
    }

    // See if this person ever had a variety session registration
    $update_or_insert_check = db_query("SELECT * FROM {booking_variety_regn} " . 
      "WHERE booking_person_nid = :nid",
      array(':nid' => $values['nid'],
    ))->fetchObject();

    if (! $update_or_insert_check) {
      // create new variety session registration information for this person
      $result = db_insert('booking_variety_regn')
        ->fields(array(
          'booking_person_nid' => $values['nid'],
          'booking_variety_ids' => drupal_json_encode($booking_variety_ids),
        ))
        ->execute();
      watchdog('booking', "Created variety session registration for person ID !nid", array('!nid' => $values['nid']));
    }
    else {
      // update the session registration information for this person
      $result = db_update('booking_variety_regn')
        ->fields(array(
          'booking_variety_ids' => drupal_json_encode($booking_variety_ids),
        ))
        ->condition('booking_person_nid', $values['nid'])
        ->execute();
      watchdog('booking', "Updated variety session registration for person ID !nid", array('!nid' => $values['nid']));
    }

    // Finished, redirect to original table
		$form_state['redirect'] = $redirect_path;
	}
}