<?php

use Drupal\xautoload\ClassLoader\ApcClassLoader;
use Drupal\xautoload\ClassLoader\ApcuClassLoader;
use Drupal\xautoload\ClassLoader\ApcuQueuedCachedClassLoader;
use Drupal\xautoload\ClassLoader\DbCacheClassLoader;
use Drupal\xautoload\ClassLoader\WinCacheClassLoader;
use Drupal\xautoload\ClassLoader\XCacheClassLoader;
use Drupal\xautoload\CacheMissObserver\CacheMissLoaderSetFinder;

/*
 * When the module has just been installed,
 * Drupal does not know yet this is a boot-level module.
 *
 * We can not rely on hook_boot() to fire, and instead register the autoloader
 * on inclusion of this *.module file.
 */
_xautoload_register_drupal();


// Hook implementations
// -----------------------------------------------------------------------------

/**
 * Implements hook_boot()
 *
 * This is only to let Drupal know we want this module to load in bootstrap.
 */
function xautoload_boot() {}

/**
 * Implements hook_custom_theme()
 *
 * We only do this because that's the first hook to fire after bootstrap.
 */
function xautoload_custom_theme() {
  xautoload()->phaseControl->enterMainPhase();
}

/**
 * Implements hook_init()
 *
 * Note:
 *   This is a first step to allow modules to register foreign namespaces.
 *   We will probably change this, to allow bootstrap modules to register their
 *   namespaces earlier in the request.
 *   We might also find a solution to cache the result of this hook between
 *   requests. This would require a different implementation of the InjectedAPI,
 *   which would no longer have a direct reference to the finder object.
 */
function xautoload_init() {
  xautoload()->phaseControl->enterMainPhase();
}

/**
 * Implements hook_system_theme_info().
 *
 * This is the first hook to fire on update.php.
 *
 * Unfortunately, hook_custom_theme() and hook_init() are not called on
 * update.php in _drupal_bootstrap_full().
 *
 * But in list_themes(), _system_rebuild_theme_data() is always called in
 * maintenance mode. And from there, hook_system_theme_info().
 *
 * @see _drupal_bootstrap_full()
 * @see list_themes()
 */
function xautoload_system_theme_info() {
  xautoload()->phaseControl->enterMainPhase();
}

/**
 * Implements hook_module_implements_alter()
 *
 * @param array &$implementations
 * @param string $hook
 */
function xautoload_module_implements_alter(&$implementations, $hook) {

  // Check if new modules have been enabled.
  if ('boot' === $hook) {

    # \Drupal\xautoload\Tests\HackyLog::log($hook);
    // hook_module_implements_alter('boot') gets called (indirectly) from
    // _system_update_bootstrap_status(), which happens each time a new module
    // is enabled.
    xautoload()->phaseControl->checkNewExtensions();
  }

  // Most hook implementations are in dedicated files.
  switch ($hook) {
    case 'init':
    case 'custom_theme':
    case 'system_theme_info':
      // Move xautoload_$hook() to the start.
      $implementations = array('xautoload' => FALSE) + $implementations;
      break;
    case 'form_system_performance_settings_alter':
      // Specify that the implementation lives in xautoload.ui.inc.
      $implementations['xautoload'] = 'ui';
      require_once __DIR__ . '/xautoload.ui.inc';
      break;
    case 'modules_enabled':
    case 'registry_files_alter':
      // Move xautoload_$hook() to the start, and specify that the
      // implementation lives in xautoload.system.inc.
      $implementations = array('xautoload' => 'system') + $implementations;
      require_once __DIR__ . '/xautoload.system.inc';
      break;
    case 'libraries_info_alter':
      $implementations['xautoload'] = 'libraries';
      require_once __DIR__ . '/xautoload.libraries.inc';
      break;
    default:
      return;
  }
}


// "Private" functions.
// -----------------------------------------------------------------------------

/**
 * Registers Drupal-related namespaces and prefixes in the xautoload loader, and
 * activates the APC (or similar) cache, if enabled.
 */
function _xautoload_register_drupal() {

  // Check that this runs only once.
  static $_first_run = TRUE;
  if (!$_first_run) {
    return;
  }
  $_first_run = FALSE;

  // Register the class loader itself.
  require_once __DIR__ . '/xautoload.early.lib.inc';
  _xautoload_register();

  $services = xautoload()->getServiceContainer();

  if ($services->system->variableGet(XAUTOLOAD_VARNAME_REPLACE_CORE)) {
    /**
     * Completely take over.
     *
     * @see _drupal_bootstrap_database()
     * @see drupal_autoload_class()
     * @see drupal_autoload_interface()
     */
    spl_autoload_unregister('drupal_autoload_class');
    spl_autoload_unregister('drupal_autoload_interface');
  }

  $lazy = $services->system->variableGet(XAUTOLOAD_VARNAME_CACHE_LAZY, FALSE);
  $decorated = $lazy
    ? $services->proxyFinder
    : $services->proxyFinder->getFinder()
  ;

  // Activate a cache, if available and enabled.
  $cache_types = $services->system->variableGet(XAUTOLOAD_VARNAME_CACHE_TYPES, array());
  if (!empty($cache_types['apcu_q']) && extension_loaded('apcu') && function_exists('apcu_store')) {
    $cached_loader = ApcuQueuedCachedClassLoader::create($decorated, $services->cacheManager);
  }
  elseif (!empty($cache_types['apc']) && extension_loaded('apc') && function_exists('apc_store')) {
    $cached_loader = ApcClassLoader::create($decorated, $services->cacheManager);
  }
  /** @noinspection NotOptimalIfConditionsInspection */
  elseif (!empty($cache_types['apcu']) && extension_loaded('apcu') && function_exists('apcu_store')) {
    $cached_loader = ApcuClassLoader::create($decorated, $services->cacheManager);
  }
  elseif (!empty($cache_types['wincache']) && extension_loaded('wincache') && function_exists('wincache_ucache_get')) {
    $cached_loader = WinCacheClassLoader::create($decorated, $services->cacheManager);
  }
  elseif (!empty($cache_types['xcache']) && extension_loaded('Xcache') && function_exists('xcache_get')) {
    $cached_loader = XCacheClassLoader::create($decorated, $services->cacheManager);
  }
  elseif (!empty($cache_types['dbcache'])) {
    $cached_loader = DbCacheClassLoader::create($decorated, $services->cacheManager);
  }

  if (isset($cached_loader)) {
    if ($lazy) {
      $decorated->observeFirstCacheMiss(new CacheMissLoaderSetFinder($cached_loader));
    }
    $cached_loader->register();
    $services->finder->unregister();
  }
  else {
    // No cache is active.
    // Initialize the finder, to fire scheduled operations.
    $services->proxyFinder->getFinder();
  }

  // Register prefixes and namespaces for enabled extensions.
  $services->proxyFinder->observeFirstCacheMiss($services->phaseControl);
}