<?php
// $Id: signup_restrict_by_role.module,v 1.2 2009-04-29 11:36:21 ebeyrent Exp $

/**
 * @file signup_restrict_by_role
 */

/**
 * Implementation of hook_form_alter
 */
function signup_restrict_by_role_form_alter(&$form, &$form_state, $form_id) {
  if($form_id == 'event_node_form') {
		// Retrieve the list of roles from the database    
	  $roles = user_roles();
	    
	  $nid = $form['nid']['#value']; 
	  $default_options = array();
	    
	  if ($nid) {
	    $result = db_query("SELECT rid FROM {signup_restrict_by_role} WHERE nid = %d", $nid);
	    while ($row = db_fetch_array($result)) {
	      array_push($default_options, $row['rid']);
	    }
	  }
	        
	  foreach ($roles as $key => $value) {
	    $roles_options[$key] = $value;
	  }
	
	  // Add the form element to toggle if signups are allowed.
	  $form['signup']['signup_restrict'] = array(
	    '#type' => 'fieldset', 
	    '#title' => t('Restrict access to certain Roles'),
	    '#collapsible' => TRUE,
	    '#collapsed' => FALSE,
	    '#tree' => TRUE,
	  );
	    
	  $form['signup']['signup_restrict']['options'] = array(
	    '#type' => 'checkboxes',
	    '#options' => $roles_options,
	    '#default_value' => $default_options,
	  );
  }
}

/**
 * Implementation of hook_nodeapi
 */
function signup_restrict_by_role_nodeapi(&$node, $op, $teaser=NULL, $page=NULL) {
  global $user;
  
  if ($node->type == 'event' && $node->signup) {
    switch($op) {
      case 'load':
        // Check if signups should be enabled for the current user
        $matches = implode(', ', array_keys($user->roles));
        $result = db_result(db_query("SELECT COUNT(rid) FROM {signup_restrict_by_role} WHERE nid = %d AND rid IN (%s)", $node->nid, $matches));
        if ($result == 0) {
          // Hrm. Are there any settings for this node? If not, default to signups enabled
          $result = db_result(db_query("SELECT COUNT(rid) FROM {signup_restrict_by_role} WHERE nid = %d", $node->nid));
          if($result > 0) {
            // This is a bit hacky, is there a better way to tell we're being loaded for editing?
            if (arg(2) != 'edit') {
              $node->signup = FALSE;
            }
          }
        }
        break;
          
      case 'insert':
      case 'update':
        db_query("DELETE FROM {signup_restrict_by_role} WHERE nid = %d", $node->nid);
        foreach ($node->signup_restrict[options] as $key => $value) {
          if ($value) {
            db_query("INSERT INTO {signup_restrict_by_role} (nid, rid) VALUES (%d, %d)", $node->nid, $key);
          }
        }
        break;
    }
  }
}