<?php

/**
 * @file
 * This module allows you to protect any page of your website by secure 
 * password. You can enter urls of pages to protect and set password per page.
 * Admin (uid = 1) or user with bypass protection permission can view page.
 */

/**
 * Implements hook_permission(). 
 */
function protected_pages_permission() {
  return array(
    'bypass pages password protection' => array(
      'title' => t('bypass pages password protection'),
      'description' => t('Bypass password protection of protected pages'),
    ),
    'access protected page password screen' => array(
      'title' => t('access protected page password screen'),
      'description' => t('Access protected page password screen.'),
    ),
    'administer protected pages configuration' => array(
      'title' => t('access protected pages configuration screen'),
      'description' => t('Access protected pages configuration screen.'),
    ),
  );
}

/**
 * Implements hook_menu().  
 */
function protected_pages_menu() {
  $items = array();

  $items['admin/config/system/protected_pages'] = array(
    'title' => 'Protected Pages',
    'description' => 'Configure protected pages setting.',
    'page callback' => 'drupal_get_form',
    'page arguments' => array('protected_pages_configure'),
    'access arguments' => array('administer protected pages configuration'),
    'file' => 'protected_pages.admin.inc',
  );
  $items['admin/config/system/protected_pages/list'] = array(
    'title' => 'Protected Pages',
    'type' => MENU_DEFAULT_LOCAL_TASK,
  );
  $items['admin/config/system/protected_pages/settings'] = array(
    'title' => 'Settings',
    'page callback' => 'drupal_get_form',
    'page arguments' => array('protected_pages_settings'),
    'access arguments' => array('administer protected pages configuration'),
    'type' => MENU_LOCAL_TASK,
    'file' => 'protected_pages.admin.inc',
  );

  $items['admin/config/system/protected_pages/%/edit'] = array(
    'title' => 'Edit Protected Pages',
    'page callback' => 'drupal_get_form',
    'page arguments' => array('protected_pages_edit', 4),
    'access arguments' => array('administer protected pages configuration'),
    'file' => 'protected_pages.admin.inc',
  );

  $items['admin/config/system/protected_pages/%/delete'] = array(
    'title' => 'Delete Protected Pages',
    'page callback' => 'drupal_get_form',
    'page arguments' => array('protected_pages_delete_confirm', 4),
    'access arguments' => array('administer protected pages configuration'),
    'type' => MENU_CALLBACK,
    'file' => 'protected_pages.admin.inc',
  );

  $items['admin/config/system/protected_pages/%/send_email'] = array(
    'title' => 'Send protected pages details to user by email',
    'page callback' => 'drupal_get_form',
    'page arguments' => array('protected_pages_send_email', 4),
    'access arguments' => array('administer protected pages configuration'),
    'file' => 'protected_pages.admin.inc',
  );

  $items['protected-page'] = array(
    'title' => 'Protected page - Enter Password',
    'title callback' => 'protected_pages_get_title',
    'description' => 'Here you can enter the password for protected pages',
    'page callback' => 'drupal_get_form',
    'page arguments' => array('protected_pages_enter_password'),
    'access callback' => 'protected_pages_access_callback',
    'type' => MENU_CALLBACK,
    'file' => 'protected_pages.inc',
  );
  return $items;
}

/**
 * Callback function to determine who can enter a password.
 */
function protected_pages_access_callback() {
  global $user;

  if ($user->uid == 1) {
    return TRUE;
  }
  if (!user_access('access protected page password screen')) {
    return FALSE;
  }

  if (empty($_GET['protected_page']) || !is_numeric($_GET['protected_page'])) {
    return FALSE;
  }

  return TRUE;
}

/**
 * Implements hook_init(). 
 */
function protected_pages_init() {
  if (user_access('bypass pages password protection')) {
    return;
  }

  $current_path = drupal_strtolower(drupal_get_path_alias($_GET['q']));
  $normal_path = drupal_get_normal_path($current_path);

  $pid = protected_pages_is_page_locked($current_path, $normal_path);
  if ($pid) {
    $query = drupal_get_destination();
    if (!empty($_SERVER['HTTP_REFERER'])) {
      $query['back'] = urlencode($current_path);
    }
    $query['protected_page'] = $pid;
    drupal_goto('protected-page', array('query' => $query));
  }
  else {
    $page_node = menu_get_object();
    if (isset($page_node->nid) && is_numeric($page_node->nid)) {
      $path_to_node = 'node/' . $page_node->nid;
      $current_path = drupal_strtolower(drupal_get_path_alias($path_to_node));
      $normal_path = drupal_get_normal_path($current_path);
      $pid = protected_pages_is_page_locked($current_path, $normal_path);
      if ($pid) {
        $query = drupal_get_destination();
        if (!empty($_SERVER['HTTP_REFERER'])) {
          $query['back'] = urlencode($current_path);
        }
        $query['protected_page'] = $pid;
        drupal_goto('protected-page', array('query' => $query));
      }
    }
  }
}

/**
 * Helper function to check whether the path is protected or not.
 */
function protected_pages_is_page_locked($current_path, $normal_path) {

  $pid = db_select('protected_pages')
      ->fields('protected_pages', array('pid'))
      ->condition(db_or()->condition('path', $current_path)->condition('path', $normal_path))
      ->range(0, 1)
      ->execute()
      ->fetchField();

  if (isset($_SESSION['_protected_page']['passwords'][$pid]['expire_time'])) {
    if (time() >= $_SESSION['_protected_page']['passwords'][$pid]['expire_time']) {
      unset($_SESSION['_protected_page']['passwords'][$pid]['request_time']);
      unset($_SESSION['_protected_page']['passwords'][$pid]['expire_time']);
    }
  }
  if (isset($_SESSION['_protected_page']['passwords'][$pid]['request_time'])) {
    return FALSE;
  }
  return $pid;
}

/**
 * Title Callback for enter password page.
 */
function protected_pages_get_title() {
  return check_plain(variable_get('protected_pages_title', t('Protected Page -- Enter password')));
}

/**
 * The default email subject. 
 */
function protected_pages_email_subject() {
  return t("Please visit this new page");
}

/**
 * The default email body. 
 */
function protected_pages_email_body() {
  return t("Dear friend,

I just created a new page on my website and wanted to invite you to
visit. The page is protected by password. Please find the details below:-

Page Url = [protected-page-url]
Page Password = password here

Thank you.
[site-name]"
  );
}

/**
 * Implements hook_mail(). 
 */
function protected_pages_mail($key, &$message, $params) {
  switch ($key) {
    case 'protected_pages_details_mail':
      $tokens = array('[protected-page-url]', '[site-name]');
      $replcements = array(
        $params['protected_page_url'], check_plain(variable_get('site_name', '')),
      );

      $body = str_replace($tokens, $replcements, $params['body']);

      $subject = $params['subject'];
      $message['subject'] = $subject;
      $message['body'][] = $body;

      break;
  }
}