<?php

declare(strict_types=1);

/**
 * @copyright 2020 Christoph Wurst <christoph@winzerhof-wurst.at>
 *
 * @author Christoph Wurst <christoph@winzerhof-wurst.at>
 * @author Joas Schilling <coding@schilljs.com>
 * @author Julius Härtl <jus@bitgrid.net>
 * @author Morris Jobke <hey@morrisjobke.de>
 * @author Robin Appelman <robin@icewind.nl>
 *
 * @license GNU AGPL version 3 or any later version
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as
 * published by the Free Software Foundation, either version 3 of the
 * License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program. If not, see <http://www.gnu.org/licenses/>.
 *
 */

namespace OC\AppFramework\Bootstrap;

use OCP\Diagnostics\IEventLogger;
use function class_exists;
use function class_implements;
use function in_array;
use OC_App;
use OC\Support\CrashReport\Registry;
use OCP\AppFramework\App;
use OCP\AppFramework\Bootstrap\IBootstrap;
use OCP\AppFramework\QueryException;
use OCP\Dashboard\IManager;
use OCP\EventDispatcher\IEventDispatcher;
use OCP\IServerContainer;
use Psr\Log\LoggerInterface;
use Throwable;

class Coordinator {
	/** @var IServerContainer */
	private $serverContainer;

	/** @var Registry */
	private $registry;

	/** @var IManager */
	private $dashboardManager;

	/** @var IEventDispatcher */
	private $eventDispatcher;

	/** @var IEventLogger */
	private $eventLogger;

	/** @var LoggerInterface */
	private $logger;

	/** @var RegistrationContext|null */
	private $registrationContext;

	/** @var string[] */
	private $bootedApps = [];

	public function __construct(
		IServerContainer $container,
		Registry $registry,
		IManager $dashboardManager,
		IEventDispatcher $eventListener,
		IEventLogger $eventLogger,
		LoggerInterface $logger
	) {
		$this->serverContainer = $container;
		$this->registry = $registry;
		$this->dashboardManager = $dashboardManager;
		$this->eventDispatcher = $eventListener;
		$this->eventLogger = $eventLogger;
		$this->logger = $logger;
	}

	public function runInitialRegistration(): void {
		$this->registerApps(OC_App::getEnabledApps());
	}

	public function runLazyRegistration(string $appId): void {
		$this->registerApps([$appId]);
	}

	/**
	 * @param string[] $appIds
	 */
	private function registerApps(array $appIds): void {
		$this->eventLogger->start('bootstrap:register_apps', '');
		if ($this->registrationContext === null) {
			$this->registrationContext = new RegistrationContext($this->logger);
		}
		$apps = [];
		foreach ($appIds as $appId) {
			$this->eventLogger->start("bootstrap:register_app:$appId", "Register $appId");
			$this->eventLogger->start("bootstrap:register_app:$appId:autoloader", "Setup autoloader for $appId");
			/*
			 * First, we have to enable the app's autoloader
			 *
			 * @todo use $this->appManager->getAppPath($appId) here
			 */
			$path = OC_App::getAppPath($appId);
			if ($path === false) {
				// Ignore
				continue;
			}
			OC_App::registerAutoloading($appId, $path);
			$this->eventLogger->end("bootstrap:register_app:$appId:autoloader");

			/*
			 * Next we check if there is an application class, and it implements
			 * the \OCP\AppFramework\Bootstrap\IBootstrap interface
			 */
			$appNameSpace = App::buildAppNamespace($appId);
			$applicationClassName = $appNameSpace . '\\AppInfo\\Application';
			try {
				if (class_exists($applicationClassName) && in_array(IBootstrap::class, class_implements($applicationClassName), true)) {
					$this->eventLogger->start("bootstrap:register_app:$appId:application", "Load `Application` instance for $appId");
					try {
						/** @var IBootstrap|App $application */
						$apps[$appId] = $application = $this->serverContainer->query($applicationClassName);
					} catch (QueryException $e) {
						// Weird, but ok
						$this->eventLogger->end("bootstrap:register_app:$appId");
						continue;
					}
					$this->eventLogger->end("bootstrap:register_app:$appId:application");

					$this->eventLogger->start("bootstrap:register_app:$appId:register", "`Application::register` for $appId");
					$application->register($this->registrationContext->for($appId));
					$this->eventLogger->end("bootstrap:register_app:$appId:register");
				}
			} catch (Throwable $e) {
				$this->logger->emergency('Error during app service registration: ' . $e->getMessage(), [
					'exception' => $e,
					'app' => $appId,
				]);
				$this->eventLogger->end("bootstrap:register_app:$appId");
				continue;
			}
			$this->eventLogger->end("bootstrap:register_app:$appId");
		}

		$this->eventLogger->start('bootstrap:register_apps:apply', 'Apply all the registered service by apps');
		/**
		 * Now that all register methods have been called, we can delegate the registrations
		 * to the actual services
		 */
		$this->registrationContext->delegateCapabilityRegistrations($apps);
		$this->registrationContext->delegateCrashReporterRegistrations($apps, $this->registry);
		$this->registrationContext->delegateDashboardPanelRegistrations($this->dashboardManager);
		$this->registrationContext->delegateEventListenerRegistrations($this->eventDispatcher);
		$this->registrationContext->delegateContainerRegistrations($apps);
		$this->eventLogger->end('bootstrap:register_apps:apply');
		$this->eventLogger->end('bootstrap:register_apps');
	}

	public function getRegistrationContext(): ?RegistrationContext {
		return $this->registrationContext;
	}

	public function bootApp(string $appId): void {
		if (isset($this->bootedApps[$appId])) {
			return;
		}
		$this->bootedApps[$appId] = true;

		$appNameSpace = App::buildAppNamespace($appId);
		$applicationClassName = $appNameSpace . '\\AppInfo\\Application';
		if (!class_exists($applicationClassName)) {
			// Nothing to boot
			return;
		}

		/*
		 * Now it is time to fetch an instance of the App class. For classes
		 * that implement \OCP\AppFramework\Bootstrap\IBootstrap this means
		 * the instance was already created for register, but any other
		 * (legacy) code will now do their magic via the constructor.
		 */
		$this->eventLogger->start('bootstrap:boot_app:' . $appId, "Call `Application::boot` for $appId");
		try {
			/** @var App $application */
			$application = $this->serverContainer->query($applicationClassName);
			if ($application instanceof IBootstrap) {
				/** @var BootContext $context */
				$context = new BootContext($application->getContainer());
				$application->boot($context);
			}
		} catch (QueryException $e) {
			$this->logger->error("Could not boot $appId: " . $e->getMessage(), [
				'exception' => $e,
			]);
		} catch (Throwable $e) {
			$this->logger->emergency("Could not boot $appId: " . $e->getMessage(), [
				'exception' => $e,
			]);
		}
		$this->eventLogger->end('bootstrap:boot_app:' . $appId);
	}

	public function isBootable(string $appId) {
		$appNameSpace = App::buildAppNamespace($appId);
		$applicationClassName = $appNameSpace . '\\AppInfo\\Application';
		return class_exists($applicationClassName) &&
			in_array(IBootstrap::class, class_implements($applicationClassName), true);
	}
}