class Plugin

final class Plugin implements PluginInterface, EventSubscriberInterface, Capable {
  
  /**
   * The composer package type of Drupal recipes.
   */
  public const RECIPE_PACKAGE_TYPE = 'drupal-recipe';
  
  /**
   * The handler for dependency unpacking.
   */
  private UnpackManager $manager;
  
  /**
   * {@inheritdoc}
   */
  public function getCapabilities() : array {
    return [
      CommandProvider::class => UnpackCommandProvider::class,
    ];
  }
  
  /**
   * {@inheritdoc}
   */
  public function activate(Composer $composer, IOInterface $io) : void {
    $this->manager = new UnpackManager($composer, $io);
  }
  
  /**
   * {@inheritdoc}
   */
  public function deactivate(Composer $composer, IOInterface $io) : void {
  }
  
  /**
   * {@inheritdoc}
   */
  public function uninstall(Composer $composer, IOInterface $io) : void {
  }
  
  /**
   * {@inheritdoc}
   */
  public static function getSubscribedEvents() : array {
    return [
      ScriptEvents::POST_UPDATE_CMD => 'unpackOnRequire',
      ScriptEvents::POST_CREATE_PROJECT_CMD => 'unpackOnCreateProject',
    ];
  }
  
  /**
   * Post update command event callback.
   */
  public function unpackOnRequire(Event $event) : void {
    if (!$this->manager->unpackOptions->options['on-require']) {
      return;
    }
    // @todo https://www.drupal.org/project/drupal/issues/3523269 Use Composer
    //   API once it exists.
    $backtrace = debug_backtrace();
    $composer = $event->getComposer();
    foreach ($backtrace as $trace) {
      if (isset($trace['object']) && $trace['object'] instanceof Installer) {
        $installer = $trace['object'];
        // Get the list of packages being required. This code is largely copied
        // from https://github.com/symfony/flex/blob/2.x/src/Flex.php#L218.
        $updateAllowList = \Closure::bind(function () {
          return $this->updateAllowList ?? [];
        }, $installer, $installer)();
        // Determine if the --no-install flag has been passed to require.
        $isInstalling = \Closure::bind(function () {
          return $this->install;
        }, $installer, $installer)();
      }
      // If the command is a require command, populate the list of recipes to
      // unpack.
      if (isset($trace['object']) && $trace['object'] instanceof RequireCommand && isset($installer, $updateAllowList, $isInstalling)) {
        // Determines if a message has been sent about require-dev and recipes.
        $devRecipeWarningEmitted = FALSE;
        $unpackCollection = new UnpackCollection();
        foreach ($updateAllowList as $package_name) {
          $packages = $composer->getRepositoryManager()
            ->getLocalRepository()
            ->findPackages($package_name);
          $package = reset($packages);
          if (!$package instanceof Package) {
            if (!$isInstalling) {
              $event->getIO()
                ->write('Recipes are not unpacked when the --no-install option is used.', verbosity: IOInterface::VERBOSE);
              return;
            }
            $event->getIO()
              ->error(sprintf('%s does not resolve to a package.', $package_name));
            return;
          }
          // Only recipes are supported.
          if ($package->getType() === self::RECIPE_PACKAGE_TYPE) {
            if ($this->manager->unpackOptions
              ->isIgnored($package)) {
              $event->getIO()
                ->write(sprintf('<info>%s</info> not unpacked because it is ignored.', $package_name), verbosity: IOInterface::VERBOSE);
            }
            elseif (UnpackManager::isDevRequirement($package)) {
              if (!$devRecipeWarningEmitted) {
                $event->getIO()
                  ->write('<info>Recipes required as a development dependency are not automatically unpacked.</info>');
                $devRecipeWarningEmitted = TRUE;
              }
            }
            else {
              $unpackCollection->add($package);
            }
          }
        }
        // Unpack any recipes that have been added to the collection.
        $this->manager
          ->unpack($unpackCollection);
        // The trace has been processed far enough and the $updateAllowList has
        // been used.
        break;

      }
    }
  }
  
  /**
   * Post create-project command event callback.
   */
  public function unpackOnCreateProject(Event $event) : void {
    $composer = $event->getComposer();
    $unpackCollection = new UnpackCollection();
    foreach ($composer->getRepositoryManager()
      ->getLocalRepository()
      ->getPackages() as $package) {
      // Only recipes are supported.
      if ($package->getType() === self::RECIPE_PACKAGE_TYPE) {
        if ($this->manager->unpackOptions
          ->isIgnored($package)) {
          $event->getIO()
            ->write(sprintf('<info>%s</info> not unpacked because it is ignored.', $package->getName()), verbosity: IOInterface::VERBOSE);
        }
        elseif (UnpackManager::isDevRequirement($package)) {
          continue;
        }
        else {
          $unpackCollection->add($package);
        }
      }
    }
    // Unpack any recipes that have been registered.
    $this->manager
      ->unpack($unpackCollection);
  }

}