<?php

/**
 * @file
 * Site security review and reporting Drupal module.
 *
 */

/**
 * Implements hook_permission().
 */
function security_review_permission() {
  return array(
    'access security review list' => array(
      'title' => t('Access security review pages'),
      'description' => t('View security review checks and output. Give only to trusted users.'),
    ),
    'run security checks' => array(
      'title' => t('Run security review checks'),
      'description' => t('Run the security review checks'),
    ),
  );
}

/**
 * Implements hook_menu().
 */
function security_review_menu() {
  $items = array();
  $items['admin/reports/security-review'] = array(
    'title' => 'Security review',
    'description' => 'Perform a review of the security of your site.',
    'page callback' => 'security_review_page',
    'access arguments' => array('access security review list'),
    'file' => 'security_review.pages.inc',
    'type' => MENU_NORMAL_ITEM,
  );
  $items['admin/reports/security-review/run'] = array(
    'title' => 'Run & review',
    'access arguments' => array('access security review list'),
    'type' => MENU_DEFAULT_LOCAL_TASK,
  );
  $items['admin/reports/security-review/toggle/%'] = array(
    'title' => 'Security review toggle',
    'page callback' => 'security_review_toggle_check',
    'page arguments' => array(4),
    'access arguments' => array('access security review list'),
    'file' => 'security_review.pages.inc',
    'type' => MENU_CALLBACK,
  );
  $items['admin/reports/security-review/help'] = array(
    'title' => 'Help',
    'page callback' => 'security_review_check_help',
    'access arguments' => array('access security review list'),
    'file' => 'security_review.pages.inc',
    'type' => MENU_LOCAL_TASK,
    'weight' => 10,
  );
  $items['admin/reports/security-review/settings'] = array(
    'title' => 'Settings',
    'page callback' => 'drupal_get_form',
    'page arguments' => array('security_review_settings'),
    'access arguments' => array('access security review list'),
    'file' => 'security_review.pages.inc',
    'type' => MENU_LOCAL_TASK,
    'weight' => 15,
  );

  return $items;
}

/**
 * Implements hook_theme().
 */
function security_review_theme($existing, $type, $theme, $path) {
  return array(
    'security_review_reviewed' => array(
      'variables' => array('items' => array(), 'header' => '', 'description' => ''),
      'file' => 'security_review.pages.inc',
      ),
    'security_review_help_options' => array(
      'variables' => array('element' => array()),
      'file' => 'security_review.pages.inc',
      ),
    'security_review_check_help' => array(
      'variables' => array('element' => array()),
      'file' => 'security_review.pages.inc',
      ),
  );
}

/**
 * Retrieve stored checks and results.
 *
 * @return array Array of checks with keys:
 *     namespace - string Check namespace
 *     reviewcheck - string Check name
 *     result - bool Whether check passed or not
 *     lastrun - UNIX timestamp of last time check ran
 *     skip - bool Whether check is being skipped or not
 *     skiptime - UNIX timestamp of when check was skipped, if set
 *     skipuid - UID of user who skipped the check, if set
 */
function security_review_get_stored_results() {
  $checks = array();
  // Retrieve results from last run of the checklist.
  $result = db_query("SELECT namespace, reviewcheck, result, lastrun, skip, skiptime, skipuid FROM {security_review}");
  foreach ($result as $record) {
    $checks[] = array(
      'namespace'   => $record->namespace,
      'reviewcheck' => $record->reviewcheck,
      'result'      => $record->result == '1' ? TRUE : FALSE,
      'lastrun'     => $record->lastrun,
      'skip'        => $record->skip == '1' ? TRUE : FALSE,
      'skiptime'    => $record->skiptime,
      'skipuid'     => $record->skipuid,
    );
  }
  return $checks;
}

/**
 * Retrieve the result from the last run of a security check.
 *
 * @return array
 *   @see security_review_get_stored_results() for format
 */
function security_review_get_last_check($namespace, $check_name) {
  $fields = array('namespace', 'reviewcheck', 'result', 'lastrun', 'skip', 'skiptime', 'skipuid');
  $result = db_select('security_review', 'sr')->fields('sr', $fields)
    ->condition('namespace', $namespace)
    ->condition('reviewcheck', $check_name)
    ->execute()->fetchAssoc();
  if (!empty($result)) {
    $result['result'] = $result['result'] === '1' ? TRUE : FALSE;
    $result['skip'] = $result['skip'] === '1' ? TRUE : FALSE;
    return $result;
  }
  return FALSE;
}

/**
 * Run the security review checklist and store the results.
 */
function security_review_run_store($checklist, $log = NULL) {
  // Allow callers, like our drush command, to decide not to log.
  if (is_null($log)) {
    $log = variable_get('security_review_log', TRUE);
  }
  // Call our private function to perform the actual review.
  $results = _security_review_run($checklist, $log);
  variable_set('security_review_last_run', time());
  // Store results and return.
  return security_review_store_results($results);
}

/**
 * Store checklist results.
 */
function security_review_store_results($results) {
  $log = variable_get('security_review_log', TRUE);
  $saved = $to_save = 0;
  foreach ($results as $module => $checks) {
    foreach ($checks as $check_name => $check) {
      $num_deleted = db_delete('security_review')
        ->condition('namespace', $module)
        ->condition('reviewcheck', $check_name)
        ->execute();
      if ($num_deleted == 1 && is_null($check['result']) && $log) {
        // Last check was deleted and current check returns null so check is
        // no longer applicable.
        $message = '!name no longer applicable for checking';
        _security_review_log($module, $check_name, $message, array('!name' => $check['title']), WATCHDOG_INFO);
      }
      // Only save checks that have a boolean result.
      elseif (!is_null($check['result'])) {
        $to_save++;
        $record = array(
          'namespace' => $module,
          'reviewcheck' => $check_name,
          'result' => $check['result'],
          'lastrun' => $check['lastrun'] ? $check['lastrun'] : REQUEST_TIME,
        );

        if (drupal_write_record('security_review', $record) == SAVED_NEW) {
          $saved++;
        }
        elseif ($log) {
          _security_review_log($module, $check_name, 'Unable to store check !reviewcheck for !namespace', array('!reviewcheck' => $check_name, '!namespace' => $module), WATCHDOG_ERROR);
        }
      }
    }
  }
  return ($to_save == $saved) ? TRUE : FALSE;
}

/**
 * Run the security review checklist and return the full results.
 */
function security_review_run_full($checklist, $log = NULL) {
  module_load_include('inc', 'security_review');
  // Allow callers, like our drush command, to decide not to log.
  if (is_null($log)) {
    $log = variable_get('security_review_log', TRUE);
  }
  // Call our private function to perform the actual review.
  $results = _security_review_run($checklist, $log);

  // Fill out the descriptions of the results.
  foreach ($results as $module => $checks) {
    foreach ($checks as $check_name => $check) {
      $function = $check['callback'] . '_help';
      // We should have loaded all necessary include files.
      if (function_exists($function)) {
        $element = call_user_func($function, $check);
        // @todo run through theme?
        $results[$module][$check_name]['help'] = $element;
      }
    }
  }
  return $results;
}

/**
 * Operation function called by Batch.
 */
function _security_review_batch_op($module, $check_name, $check, $log, &$context) {
  module_load_include('inc', 'security_review');
  $context['message'] = $check['title'];
  // Run the check.
  $check_result = _security_review_run_check($module, $check_name, $check, $log);
  if (!empty($check_result)) {
    $context['results'][$module][$check_name] = $check_result;
  }
}

/**
 * Finished callback for Batch processing the checklist.
 */
function _security_review_batch_finished($success, $results, $operations) {
  variable_set('security_review_last_run', time());
  module_load_include('inc', 'security_review');
  if ($success) {
    if (!empty($results)) {
      // Store results in our present table.
      $storage_result = security_review_store_results($results);
    }
    drupal_set_message(t('Review complete'));
  }
  else {
   $error_operation = reset($operations);
   $message = 'An error occurred while processing ' . $error_operation[0] . ' with arguments :' . print_r($error_operation[0], TRUE);
   _security_review_log('', '', $message, array(), WATCHDOG_ERROR);
    drupal_set_message(t('The review did not store all results, please run again or check the logs for details.'));
  }
}

/**
 * Helper function returns skipped checks.
 */
function security_review_skipped_checks() {
  $skipped = array();

  $results = db_query("SELECT namespace, reviewcheck, result, lastrun, skip, skiptime, skipuid FROM {security_review} WHERE skip = 1");
  while ($record = $results->fetchAssoc()) {
    $skipped[$record['namespace']][$record['reviewcheck']] = $record;
  }

  return $skipped;
}

/**
 * Implementation of hook_security_review_log().
 */
function security_review_security_review_log($module, $check_name, $message, $variables, $type) {
  // Log using watchdog().
  watchdog('security_review', $message, $variables, $type);
}
