<?php
// $Id: signup_restrict_by_role.module,v 1.1.2.1 2008-05-23 01:26:54 simon Exp $

/**
 * @file signup_restrict_by_role
 */

/**
 * Implementation of hook_form_alter
 *
 * @param unknown_type $form_id
 * @param unknown_type $form
 */
function signup_restrict_by_role_form_alter($form_id, &$form) {
  if ($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' => TRUE,
      '#tree' => TRUE,
    );
    
    $form['signup']['signup_restrict']['options'] = array(
      '#type' => 'checkboxes',
      '#options' => $roles_options,
      '#default_value' => $default_options,
    );
    
  }
}

/**
 * Implementation of hook_nodeapi
 *
 * @param unknown_type $node
 * @param unknown_type $op
 * @param unknown_type $a3
 * @param unknown_type $a4
 */
function signup_restrict_by_role_nodeapi(&$node, $op, $a3 = NULL, $a4 = NULL) {
  global $user;
  
  if ($node->type == 'event' && $node->signup) {
    switch($op) {
      case 'load':
        // Check if signups should be enabled for the current user
        $roles = $user->roles;
        $matches = implode(', ', array_keys($roles));
        $result = db_query("SELECT rid FROM {signup_restrict_by_role} WHERE nid = %d AND rid IN (%s)", $node->nid, $matches);
        if (db_num_rows($result) == 0) {
          
          // Hrm. Are there any settings for this node? If not, default to signups enabled
          $result = db_query("SELECT rid FROM {signup_restrict_by_role} WHERE nid = %d", $node->nid);
          if (db_num_rows($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;
    }
  }
}