<?php
// $Id: strongarm.module,v 1.1.2.6.2.17 2010-08-05 14:43:24 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().
  $_GET['q'] = isset($_REQUEST['q']) ? strongarm_language_strip($_REQUEST['q']) : NULL;
  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 {
    $var_conf = array();
    foreach (strongarm_vars_load(FALSE, TRUE) as $var) {
      $var_conf[$var->name] = $var->value;
    }
    cache_set('strongarm', $var_conf);
  }
  global $conf;

  // Store the original variable values. This allows additional calls to
  // strongarm_set_conf() to properly set Strongarm values.
  static $original_conf;
  if (!isset($original_conf)) {
    $original_conf = $conf;
  }

  $conf = array_merge($var_conf, $original_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 hook_help().
 */
function strongarm_help($path, $arg) {
  switch ($path) {
    case 'admin/help#strongarm':
      $output = file_get_contents(drupal_get_path('module', 'strongarm') .'/README.txt');
      return module_exists('markdown') ? filter_xss_admin(module_invoke('markdown', 'filter', 'process', 0, -1, $output)) : '<pre>'. check_plain($output) .'</pre>';
    case 'admin/settings/strongarm':
      return '<p>'. t("Strongarm lets site builders manage default variable settings. All the default values provided by Strongarm are listed on this page. Any overridden value can be reverted to its default by selecting its checkbox and clicking 'Reset to defaults'.") .'</p>';
  }
}

/**
 * Load all variables (DB and Strongarmed).
 */
function strongarm_vars_load($sorted = TRUE, $reset = FALSE) {
  ctools_include('export');
  static $vars;

  // Ensure that the schema cache is not stale when trying to load.
  $schema = drupal_get_schema('variable');
  if (!isset($schema['export']) || $reset) {
    ctools_export_load_object_reset('variable');
    drupal_get_schema('variable', TRUE);
  }

  // Load vars.
  if (!isset($vars) || $reset) {
    $vars = ctools_export_load_object('variable');
    if ($sorted) {
      ksort($vars);
    }
  }
  return $vars;
}

/**
 * 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');
  }
}

/**
 * Implementation of hook_features_pipe_alter() for node component.
 * Add node type variables on behalf of core modules.
 */
function strongarm_features_pipe_node_alter(&$pipe, $data, $export, $module_name) {
  if (!empty($data)) {
    $variables = array(
      'comment',
      'comment_anonymous',
      'comment_controls',
      'comment_default_mode',
      'comment_default_order',
      'comment_default_per_page',
      'comment_form_location',
      'comment_preview',
      'comment_subject_field',
      'language_content_type',
      'node_options',
      'upload',
    );
    foreach ($data as $node_type) {
      foreach ($variables as $variable_name) {
        $pipe['variable'][] = "{$variable_name}_{$node_type}";
      }
    }
  }
}