<?php
// $Id


/**
 * When enabled this module will add a required field to forms of your choice
 * asking a simple question to avoid automatic content creation by
 * f.e. spambots. The question and answers are custimizable.
 */
 
/* Implementation of hook_help */

function riddler_help($section = 'admin/help#riddler') {
  switch ($section) {
      case 'admin/modules#description':
            return t('Requires anonymous users to answer a simple question to be answered forms are processed. A primitive but effective way to counter spam.');
      break;
  }
}

/* Implementation of hook_perm */

function riddler_perm () {
	return array(
		'administer riddler',
	);
}

/* Implementation of hook_menu */

function riddler_menu($may_cache) {
	$items = array();
	
	$access = user_access('administer riddler');
	$items[] = array(
   	'path' => 'admin/settings/captcha/riddler',
     	'title' => t('Riddler'),
     	'description' => t('Allows you to force a question to a number of forms to counter f.e. spammers.'),
     	'callback' => 'drupal_get_form',
     	'callback arguments' => array('riddler_settings'),
     	'access' => $access,
     	'type' => MENU_LOCAL_TASK
   );
   return $items;
}

/* Riddler settings form, called by drupal_get_form in menu */

function riddler_settings() {
	$form['question'] = array(
		'#type' => 'textfield',
		'#title' => t('Question'),
		'#description' => t('A question that you require anonymous users to answer'),
		'#default_value' => variable_get("riddler_question", "Do you hate spam? (yes or no)"),
		'#required' => TRUE,
	); 
	$form['answer'] = array(
		'#type' => 'textfield',
		'#title' => t('Answer'),
		'#default_value' => variable_get("riddler_answer", "yes"),
		'#description' => t('Answer to the above question. Answers are not case sensitive'),
		'#required' => TRUE,
	); 
	
	return system_settings_form($form);
}

/* Processing the settings form */

function riddler_settings_submit ($form_id, $form_values) {
	variable_set("riddler_question", $form_values['question']);
	variable_set("riddler_answer", $form_values['answer']);
}

/* Captcha implementation of Riddler */

function riddler_captcha() {
	$args = func_get_args();
 	$op = array_shift($args);
 	switch ($op) {
 		case 'list' :
 			return array("Riddler");
 		break;
 		case 'generate' :
 			$result = array();
			$captcha_type = array_shift($args);
 			if ($captcha_type == "Riddler") {
 				$result = riddler_form();
 			}
 			return $result;
 		break;
 			
 	} 
}

function riddler_form () {
	$form['value'] = (string)(variable_get("riddler_answer", "yes"));
	$form['form']['captcha_challenge'] = array(
		'#type' => 'textfield',
      '#title' => variable_get("riddler_question", "Do you hate spam? (yes or no)"),
      '#required' => TRUE,
      '#description' => t('Security question, designed to stop automated spam bots'),
   	'#weight' => 0,
   	
   );	
   return $form;
}