<?php
/* $Id: recaptcha.module,v 1.12 2007-07-20 07:25:44 robloach Exp $ */

/**
* Display help and module information
* @param section which section of the site we're displaying help
* @return help text for section
*/
function recaptcha_help($section = '') {
  $output = '';
  switch ($section) {
    case 'admin/modules#name':
      $output .= t('reCAPTCHA');
      break;
    case 'admin/modules#description':
    case 'admin/user/captcha/recaptcha':
      $output .= t('Uses the <a href="@url" target="_blank">reCAPTCHA</a> web service to improve the CAPTCHA system and protect email addresses.', array('@url' => url('http://www.recaptcha.net')));
      break;
    case 'admin/help#recaptcha':
      $output .= '<p>' .
        t('Uses the reCAPTCHA web service to improve the CAPTCHA module and protect email addresses. For more information on what reCAPTCHA is, visit <a href="@url" target="_blank">the official website</a>.', array('@url' => url('http://www.recaptcha.net'))) .
        '</p><h3>' .
        t('Configuration') .
        '</h3><p>' .
        t('The settings associated with reCAPTCHA can be found in the <a href="@recaptchatab">reCAPTCHA tab</a>, in the <a href="@captchasettings">CAPTCHA settings</a>. You must set your public and private reCAPTCHA keys in order to use the module. Once the public and private keys are set, visit the <a href="@captchasettings">CAPTCHA settings</a>, where you can choose where reCAPTCHA should be displayed.', array('@recaptchatab' => url('admin/user/captcha/recaptcha'), '@captchasettings' => url('admin/user/captcha'))) .
        '</p><h3>' .
        t('Mailhide Input Format') .
        '</h3><p>' .
        t('You can also head over to the <a href="@inputformats">input format settings</a> and add the <a href="@url" target="_blank">reCAPTCHA Mailhide</a> input filter to hide posted emails.', array('@inputformats' => url('admin/settings/filters'), '@url' => url('http://mailhide.recaptcha.net'))) .
        '</p>';
      break;
  }
  return $output;
} // function recaptcha_help

/**
 * Implementation of hook_menu().
 */
function recaptcha_menu($may_cache) {
  $items = array();
  if ($may_cache) {
    $items[] = array(
      'path' => 'admin/user/captcha/recaptcha',
      'title' => t('reCAPTCHA'),
      'description' => t('Administer the reCAPTCHA web service.'),
      'callback' => 'drupal_get_form',
      'callback arguments' => array('recaptcha_admin_settings'),
      'access' => user_access('administer recaptcha'),
      'type' => MENU_LOCAL_TASK,
    );
  }
  return $items;
} // function recaptcha_menu

/**
* Valid permissions for this module
* @return array An array of valid permissions for the onthisdate module
*/
function recaptcha_perm() {
  return array('administer recaptcha');
} // function recaptcha_perm()

/**
 * Let the user know that the reCAPTCHA PHP library is not installed
 */   
function _recaptcha_library_not_found() {
  global $calledalready;
  if(!$calledalready) {
    $calledalready = TRUE;
    drupal_set_message(t('The <a href="@url" target="_blank">reCAPTCHA PHP library</a> was not found. Please install it into %recaptchadir.', array('@url' => 'http://recaptcha.net/plugins/php', '%recaptchadir' => drupal_get_path('module', 'recaptcha') . '/recaptcha')), 'error');
    if(!function_exists('recaptcha_get_signup_url')) {
      function recaptcha_get_signup_url($domain, $appname) {
        return 'http://recaptcha.net/api/getkey?domain=' . urlencode($domain) . '&appname=' . urlencode($appname);
      }
    }
    if(!function_exists('recaptcha_get_html')) {
      function recaptcha_get_html($pubkey, $error = null, $use_ssl = false) {
        return NULL;
      }
    }
    if(!function_exists('recaptcha_check_answer')) {
      function recaptcha_check_answer($privkey, $remoteip, $challenge, $response) {
        return NULL;
      }
    }
    if(!function_exists('recaptcha_mailhide_html')) {
      function recaptcha_mailhide_html($mailhide_pubkey, $mailhide_privkey, $email) {
        return $email;
      }
    }
  }
} // function _recaptcha_library_not_found()

/**
 * Implementation of admin settings().
 */
function recaptcha_admin_settings() {
  global $recaptcha_api_server, $recaptcha_api_secure_server, $recaptcha_verify_server;
  @(include_once('recaptcha/recaptchalib.php')) or _recaptcha_library_not_found();
  $form = array();
  $form['recaptcha_public_key'] = array(
    '#type' => 'textfield',
    '#title' => t('Public Key'),
    '#default_value' => variable_get('recaptcha_public_key', ''),
    '#maxlength' => 40,
    '#description' => t('The public key given to you when you <a href="@url" target="_blank">registered at reCAPTCHA.net</a>.', array('@url' => url(recaptcha_get_signup_url($_SERVER['SERVER_NAME'], variable_get('site_name', ''))))),
   );
  $form['recaptcha_private_key'] = array(
    '#type' => 'textfield',
    '#title' => t('Private Key'),
    '#default_value' => variable_get('recaptcha_private_key', ''),
    '#maxlength' => 40,
    '#description' => t('The private key given to you when you <a href="@url" target="_blank">registered at reCAPTCHA.net</a>.', array('@url' => url(recaptcha_get_signup_url($_SERVER['SERVER_NAME'], variable_get('site_name', ''))))),
   );
  $form['recaptcha_server_settings'] = array(
    '#type' => 'fieldset',
    '#title' => t('Server Settings'),
    '#collapsible' => TRUE,
    '#collapsed' => TRUE,
  );
  $form['recaptcha_server_settings']['recaptcha_api_server'] = array(
    '#type' => 'textfield',
    '#title' => t('API Server'),
    '#default_value' => variable_get('recaptcha_api_server', isset($recaptcha_api_server) ? $recaptcha_api_server : 'http://api.recaptcha.net'),
    '#description' => t('The reCAPTCHA API Server to connect to.'),
  );
  $form['recaptcha_server_settings']['recaptcha_secure_connection'] = array(
    '#type' => 'checkbox',
    '#title' => t('Secure Connection'),
    '#default_value' => variable_get('recaptcha_secure_connection', FALSE),
    '#description' => t('Connect to the reCAPTCHA server using a secure connection.'),
  );
  $form['recaptcha_server_settings']['recaptcha_api_secure_server'] = array(
    '#type' => 'textfield',
    '#title' => t('API Secure Server'),
    '#default_value' => variable_get('recaptcha_api_secure_server', isset($recaptcha_api_secure_server) ? $recaptcha_api_secure_server : 'https://api-secure.recaptcha.net'),
    '#description' => t('The secure reCAPTCHA API Server to connect to when using a secure connection.'),
  );
  $form['recaptcha_server_settings']['recaptcha_verify_server'] = array(
    '#type' => 'textfield',
    '#title' => t('Verify Server'),
    '#default_value' => variable_get('recaptcha_verify_server', isset($recaptcha_verify_server) ? $recaptcha_verify_server : 'api-verify.recaptcha.net'),
    '#description' => t('The server to use to verify the information.'),
  );

  return system_settings_form($form);
} // function recaptcha_admin_settings

/**
 * reCAPTCHA implementation of hook_captcha
 */
function recaptcha_captcha() {  
  $args = func_get_args();
  $op = array_shift($args); 
  switch($op) {
    case 'list':
      return array('reCAPTCHA');
      
    case 'generate':
      $captcha_type = array_shift($args);
      $result = array();
      if($captcha_type == "reCAPTCHA") {
              
        global $recaptcha_api_server, $recaptcha_api_secure_server, $recaptcha_verify_server;
        @(include_once('recaptcha/recaptchalib.php')) or _recaptcha_library_not_found();
        drupal_add_css(drupal_get_path('module', 'recaptcha') . '/recaptcha.css');
        
        $recaptcha_api_server = variable_get('recaptcha_api_server', isset($recaptcha_api_server) ? $recaptcha_api_server : 'http://api.recaptcha.net');
        $recaptcha_api_secure_server = variable_get('recaptcha_api_secure_server', isset($recaptcha_api_secure_server) ? $recaptcha_api_secure_server : 'https://api-secure.recaptcha.net');
        $recaptcha_verify_server = variable_get('recaptcha_verify_server', isset($recaptcha_verify_server) ? $recaptcha_verify_server : 'api-verify.recaptcha.net');
        
        $result['preprocess'] = TRUE;
        $result['value'] = TRUE;
        $result['form']['captcha_challenge'] = array (
          '#type' => 'item',
          '#description' => recaptcha_get_html(variable_get('recaptcha_public_key', ''), NULL, variable_get('recaptcha_secure_connection', FALSE)),
          '#weight' => 0,
          '#required' => TRUE,
        );
      }
      return $result;
      
    case 'process':
      @(include_once('recaptcha/recaptchalib.php')) or _recaptcha_library_not_found();
      $resp = recaptcha_check_answer(
        variable_get('recaptcha_private_key', ''),
        $_SERVER['REMOTE_ADDR'],
        $_POST['recaptcha_challenge_field'],
        $_POST['recaptcha_response_field']);
      if($resp->is_valid) {
        return TRUE;
      } else {
        form_set_error('captcha_answer', t('The reCAPTCHA code you entered was incorrect.'));
        return FALSE;
      }
    break;
  }
} // function recaptcha_captcha

/**
 * reCAPTCHA implementation of hook_filter
 */ 
function recaptcha_filter($op, $delta = 0, $format = -1, $text = '') {
  switch ($op) {
    case 'list':
      return array(0 => t('reCAPTCHA Mailhide'));

    case 'description':
      return recaptcha_filter_tips($delta, $format);

    case 'settings':
        @(include_once('recaptcha/recaptchalib.php')) or _recaptcha_library_not_found();
        $form['filter_recaptcha'] = array('#type' => 'fieldset', '#title' => t('reCAPTCHA Mailhide Keys'), '#collapsible' => TRUE, '#collapsed' => FALSE);
        $form['filter_recaptcha']["recaptcha_mailhide_public_key_$format"] = array(
          '#type' => 'textfield',
          '#title' => t('Public Key'),
          '#default_value' => variable_get("recaptcha_mailhide_public_key_$format", ''),
          '#maxlength' => 50,
          '#description' => t('Your public Mailhide key obtained from <a href="@url" target="_blank">reCAPTCHA</a>.', array('@url' => 'http://mailhide.recaptcha.net/apikey')),
          );
        $form['filter_recaptcha']["recaptcha_mailhide_private_key_$format"] = array(
          '#type' => 'textfield',
          '#title' => t('Private Key'),
          '#default_value' => variable_get("recaptcha_mailhide_private_key_$format", ''),
          '#maxlength' => 50,
          '#description' => t('Your private Mailhide key obtained from <a href="@url" target="_blank">reCAPTCHA</a>.', array('@url' => 'http://mailhide.recaptcha.net/apikey')),
          );
        return $form;
      break;

    case 'process':
      global $recaptcha_mailhide_public_key, $recaptcha_mailhide_private_key;
      @(include_once('recaptcha/recaptchalib.php')) or _recaptcha_library_not_found();
      $recaptcha_mailhide_public_key = variable_get("recaptcha_mailhide_public_key_$format", '');
      $recaptcha_mailhide_private_key = variable_get("recaptcha_mailhide_private_key_$format", '');
      
      $text   = ' ' . $text . ' ';
      $text = preg_replace_callback("!(<p>|<li>|<br\s*/?>|[ \n\r\t\(])([A-Za-z0-9._-]+@[A-Za-z0-9._+-]+\.[A-Za-z]{2,4})([.,?]?)(?=(</p>|</li>|<br\s*/?>|[ \n\r\t\)]))!i", '_recaptcha_replace', $text);
      $text = substr($text, 1, -1);
      
      unset($recaptcha_mailhide_public_key);
      unset($recaptcha_mailhide_private_key);
      return $text;

    default:
      return $text;
  }
}

/**
 * reCAPTCHA implementation of hook_filter_tips
 */
function recaptcha_filter_tips($delta, $format, $long = false) {
  return t('E-Mail addresses are hidden with <a href="@url" target="_blank">reCAPTCHA Mailhide</a>.', array('@url' => 'http://mailhide.recaptcha.net/'));
}

/**
 * Private reCAPTCHA function to replace an email regex match
 */ 
function _recaptcha_replace($match) {
  global $recaptcha_mailhide_public_key, $recaptcha_mailhide_private_key;
  $email = recaptcha_mailhide_html($recaptcha_mailhide_public_key, $recaptcha_mailhide_private_key, $match[2]);
  return $match[1] . $email . $match[3];
}