<?php
// $Id: strongarm.module,v 1.1.2.6.2.9 2010-02-06 01:17:08 yhahn Exp $

/**
 * Implementation of hook_init().
 */
function strongarm_init() {
  strongarm_set_conf();

  // This is a workaround for the very early check of the 'site_frontpage'
  // variable in the Drupal bootstrap process. The workaround re-runs
  // drupal_init_path() to ensure the strongarm'ed version of
  // 'site_frontpage' is used. Note that this may be too late if other modules
  // weighted even lower than strongarm (which is a superlightweight -1000)
  // rely on $_GET['q'] or 'site_frontpage' in hook_init().
  $_GET['q'] = strongarm_language_strip($_REQUEST['q']);
  drupal_init_path();
}

/**
 * Retrieve variable configuration from the cache.
 */
function strongarm_set_conf($reset = FALSE) {
  $varcache = cache_get('variables', 'cache');
  $cache = cache_get('strongarm', 'cache');
  // The > comparison here is cautious but ensures that the strongarm cache
  // actually was populated after the variable cache. It is possible with
  // >= for the var cache to be populated again during the same stale second.
  if (!$reset && ($cache && $varcache && $cache->created > $varcache->created)) {
    $var_conf = $cache->data;
  }
  else {
    // Ensure that the schema cache is not stale when we init.
    $schema = drupal_get_schema('variable');
    if (!isset($schema['export'])) {
      drupal_get_schema('variable', TRUE);
    }

    $var_conf = array();
    ctools_include('export');
    foreach (ctools_export_load_object('variable') as $var) {
      $var_conf[$var->name] = $var->value;
    }
    cache_set('strongarm', $var_conf);
  }
  global $conf;
  $conf = array_merge($var_conf, $conf);
}

/**
 * Remove the language prefix for a given path.
 * Strongarm implements this itself as language_initialize() directly affects
 * $_GET['q'] and cannot be reused.
 */
function strongarm_language_strip($path) {
  // Configured presentation language mode.
  $mode = variable_get('language_negotiation', LANGUAGE_NEGOTIATION_NONE);

  // Get a list of enabled languages.
  $languages = language_list('enabled');
  $languages = $languages[1];

  if (in_array($mode, array(LANGUAGE_NEGOTIATION_PATH_DEFAULT, LANGUAGE_NEGOTIATION_PATH))) {
    $args = explode('/', $path);
    $prefix = array_shift($args);
    // Search prefix within enabled languages.
    foreach ($languages as $language) {
      if (!empty($language->prefix) && $language->prefix == $prefix) {
        return implode('/', $args);
      }
    }
  }
  return $path;
}

/**
 * Implementation of hook_menu().
 */
function strongarm_menu() {
  $items = array();
  $items['admin/settings/strongarm'] = array(
    'title' => 'Strongarm',
    'description' => 'Manage Drupal variable settings that have been strongarmed.',
    'page callback' => 'drupal_get_form',
    'page arguments' => array('strongarm_admin_form'),
    'access callback' => 'user_access',
    'access arguments' => array('administer site configuration'),
    'file' => 'strongarm.admin.inc',
    'type' => MENU_NORMAL_ITEM,
  );
  return $items;
}

/**
 * Implementation of hook_form_alter() for system_module form.
 * Clear strongarm & variable caches on modules page.
 */
function strongarm_form_system_module_alter(&$form, &$form_state) {
  strongarm_flush_caches();
}

/**
 * Implementation of hook_theme().
 */
function strongarm_theme() {
  return array(
    'strongarm_admin_form' => array(
      'arguments' => array(),
      'file' => 'strongarm.admin.inc',
      'path' => drupal_get_path('module', 'strongarm'),
    ),
  );
}

/**
 * Implementation of hook_flush_caches().
 */
function strongarm_flush_caches() {
  cache_clear_all('variables', 'cache');
  cache_clear_all('strongarm', 'cache');
}

/**
 * Implementation of hook_schema_alter().
 * Makes the variables table usable by ctools' export.inc.
 */
function strongarm_schema_alter(&$schema) {
  $schema['variable']['export'] = array(
    'key' => 'name',
    'identifier' => 'strongarm',
    'default hook' => 'strongarm',
    'api' => array(
      'owner' => 'strongarm',
      'api' => 'strongarm',
      'minimum_version' => 1,
      'current_version' => 1,
    ),
  );
  $schema['variable']['fields']['value']['serialize'] = TRUE;
}

/**
 * Implementation of hook_features_revert().
 */
if (!function_exists('variable_features_revert')) {
  function variable_features_revert($module) {
    ctools_component_features_revert('variable', $module);
    cache_clear_all('variables', 'cache');
  }
}