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);
    }

}