1 files changed, 150 insertions, 0 deletions
diff --git a/lib/private/Translation/TranslationManager.php b/lib/private/Translation/TranslationManager.php
new file mode 100644
index 00000000000..08f9f36678a
--- /dev/null
+++ b/lib/private/Translation/TranslationManager.php
@@ -0,0 +1,150 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * SPDX-FileCopyrightText: 2023 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+
+namespace OC\Translation;
+
+use InvalidArgumentException;
+use OC\AppFramework\Bootstrap\Coordinator;
+use OCP\IConfig;
+use OCP\IServerContainer;
+use OCP\IUserSession;
+use OCP\PreConditionNotMetException;
+use OCP\Translation\CouldNotTranslateException;
+use OCP\Translation\IDetectLanguageProvider;
+use OCP\Translation\ITranslationManager;
+use OCP\Translation\ITranslationProvider;
+use OCP\Translation\ITranslationProviderWithId;
+use OCP\Translation\ITranslationProviderWithUserId;
+use Psr\Container\ContainerExceptionInterface;
+use Psr\Container\NotFoundExceptionInterface;
+use Psr\Log\LoggerInterface;
+use RuntimeException;
+use Throwable;
+
+class TranslationManager implements ITranslationManager {
+	/** @var ?ITranslationProvider[] */
+	private ?array $providers = null;
+
+	public function __construct(
+		private IServerContainer $serverContainer,
+		private Coordinator $coordinator,
+		private LoggerInterface $logger,
+		private IConfig $config,
+		private IUserSession $userSession,
+	) {
+	}
+
+	public function getLanguages(): array {
+		$languages = [];
+		foreach ($this->getProviders() as $provider) {
+			$languages = array_merge($languages, $provider->getAvailableLanguages());
+		}
+		return $languages;
+	}
+
+	public function translate(string $text, ?string &$fromLanguage, string $toLanguage): string {
+		if (!$this->hasProviders()) {
+			throw new PreConditionNotMetException('No translation providers available');
+		}
+
+		$providers = $this->getProviders();
+		$json = $this->config->getAppValue('core', 'ai.translation_provider_preferences', '');
+
+		if ($json !== '') {
+			$precedence = json_decode($json, true);
+			$newProviders = [];
+			foreach ($precedence as $className) {
+				$provider = current(array_filter($providers, function ($provider) use ($className) {
+					return $provider instanceof ITranslationProviderWithId ? $provider->getId() === $className : $provider::class === $className;
+				}));
+				if ($provider !== false) {
+					$newProviders[] = $provider;
+				}
+			}
+			// Add all providers that haven't been added so far
+			$newProviders += array_udiff($providers, $newProviders, function ($a, $b) {
+				return ($a instanceof ITranslationProviderWithId ? $a->getId() : $a::class) <=> ($b instanceof ITranslationProviderWithId ? $b->getId() : $b::class);
+			});
+			$providers = $newProviders;
+		}
+
+		if ($fromLanguage === null) {
+			foreach ($providers as $provider) {
+				if ($provider instanceof IDetectLanguageProvider) {
+					if ($provider instanceof  ITranslationProviderWithUserId) {
+						$provider->setUserId($this->userSession->getUser()?->getUID());
+					}
+					$fromLanguage = $provider->detectLanguage($text);
+				}
+
+				if ($fromLanguage !== null) {
+					break;
+				}
+			}
+
+			if ($fromLanguage === null) {
+				throw new InvalidArgumentException('Could not detect language');
+			}
+		}
+
+		if ($fromLanguage === $toLanguage) {
+			return $text;
+		}
+
+		foreach ($providers as $provider) {
+			try {
+				if ($provider instanceof ITranslationProviderWithUserId) {
+					$provider->setUserId($this->userSession->getUser()?->getUID());
+				}
+				return $provider->translate($fromLanguage, $toLanguage, $text);
+			} catch (RuntimeException $e) {
+				$this->logger->warning("Failed to translate from {$fromLanguage} to {$toLanguage} using provider {$provider->getName()}", ['exception' => $e]);
+			}
+		}
+
+		throw new CouldNotTranslateException($fromLanguage);
+	}
+
+	public function getProviders(): array {
+		$context = $this->coordinator->getRegistrationContext();
+
+		if ($this->providers !== null) {
+			return $this->providers;
+		}
+
+		$this->providers = [];
+		foreach ($context->getTranslationProviders() as $providerRegistration) {
+			$class = $providerRegistration->getService();
+			try {
+				$this->providers[$class] = $this->serverContainer->get($class);
+			} catch (NotFoundExceptionInterface|ContainerExceptionInterface|Throwable $e) {
+				$this->logger->error('Failed to load translation provider ' . $class, [
+					'exception' => $e
+				]);
+			}
+		}
+
+		return $this->providers;
+	}
+
+	public function hasProviders(): bool {
+		$context = $this->coordinator->getRegistrationContext();
+		return !empty($context->getTranslationProviders());
+	}
+
+	public function canDetectLanguage(): bool {
+		foreach ($this->getProviders() as $provider) {
+			if ($provider instanceof IDetectLanguageProvider) {
+				return true;
+			}
+		}
+		return false;
+	}
+}