Implement TextToImage OCP API

Signed-off-by: Marcel Klehr <mklehr@gmx.net>

core/Controller/TextToImageApiController.php

@@ -0,0 +1,221 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * @copyright Copyright (c) 2023 Marcel Klehr <mklehr@gmx.net>
+ *
+ * @author Marcel Klehr <mklehr@gmx.net>
+ *
+ * @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\Core\Controller;
+
+use OC\Files\AppData\AppData;
+use OCA\Core\ResponseDefinitions;
+use OCP\AppFramework\Http;
+use OCP\AppFramework\Http\Attribute\AnonRateLimit;
+use OCP\AppFramework\Http\Attribute\NoAdminRequired;
+use OCP\AppFramework\Http\Attribute\PublicPage;
+use OCP\AppFramework\Http\Attribute\UserRateLimit;
+use OCP\AppFramework\Http\DataResponse;
+use OCP\AppFramework\Http\FileDisplayResponse;
+use OCP\IL10N;
+use OCP\IRequest;
+use OCP\TextToImage\Exception\TaskNotFoundException;
+use OCP\TextToImage\Task;
+use OCP\TextToImage\IManager;
+use OCP\PreConditionNotMetException;
+
+/**
+ * @psalm-import-type CoreTextToImageTask from ResponseDefinitions
+ */
+class TextToImageApiController extends \OCP\AppFramework\OCSController {
+	public function __construct(
+		string                     $appName,
+		IRequest                   $request,
+		private IManager           $textToImageManager,
+		private IL10N              $l,
+		private ?string            $userId,
+		private AppData			   $appData,
+	) {
+		parent::__construct($appName, $request);
+	}
+
+	/**
+	 * @PublicPage
+	 *
+	 * Check whether this feature is available
+	 *
+	 * @return DataResponse<Http::STATUS_OK, array{isAvailable: bool}, array{}>
+	 */
+	public function isAvailable(): DataResponse {
+		return new DataResponse([
+			'isAvailable' => $this->textToImageManager->hasProviders(),
+		]);
+	}
+
+	/**
+	 * This endpoint allows scheduling a text to image task
+	 *
+	 * @param string $input Input text
+	 * @param string $appId ID of the app that will execute the task
+	 * @param string $identifier An arbitrary identifier for the task
+	 *
+	 * @return DataResponse<Http::STATUS_OK, array{task: CoreTextToImageTask}, array{}>|DataResponse<Http::STATUS_BAD_REQUEST|Http::STATUS_PRECONDITION_FAILED, array{message: string}, array{}>
+	 *
+	 * 200: Task scheduled successfully
+	 * 400: Scheduling task is not possible
+	 * 412: Scheduling task is not possible
+	 */
+	#[PublicPage]
+	#[UserRateLimit(limit: 20, period: 120)]
+	#[AnonRateLimit(limit: 5, period: 120)]
+	public function schedule(string $input, string $type, string $appId, string $identifier = ''): DataResponse {
+		$task = new Task($input, $appId, $this->userId, $identifier);
+		try {
+			$this->textToImageManager->scheduleTask($task);
+
+			$json = $task->jsonSerialize();
+
+			return new DataResponse([
+				'task' => $json,
+			]);
+		} catch (PreConditionNotMetException) {
+			return new DataResponse(['message' => $this->l->t('No text to image provider is available')], Http::STATUS_PRECONDITION_FAILED);
+		}
+	}
+
+	/**
+	 * This endpoint allows checking the status and results of a task.
+	 * Tasks are removed 1 week after receiving their last update.
+	 *
+	 * @param int $id The id of the task
+	 *
+	 * @return DataResponse<Http::STATUS_OK, array{task: CoreTextToImageTask}, array{}>|DataResponse<Http::STATUS_NOT_FOUND|Http::STATUS_INTERNAL_SERVER_ERROR, array{message: string}, array{}>
+	 *
+	 * 200: Task returned
+	 * 404: Task not found
+	 */
+	#[PublicPage]
+	public function getTask(int $id): DataResponse {
+		try {
+			$task = $this->textToImageManager->getUserTask($id, $this->userId);
+
+			$json = $task->jsonSerialize();
+
+			return new DataResponse([
+				'task' => $json,
+			]);
+		} catch (TaskNotFoundException $e) {
+			return new DataResponse(['message' => $this->l->t('Task not found')], Http::STATUS_NOT_FOUND);
+		} catch (\RuntimeException $e) {
+			return new DataResponse(['message' => $this->l->t('Internal error')], Http::STATUS_INTERNAL_SERVER_ERROR);
+		}
+	}
+
+	/**
+	 * This endpoint allows checking the status and results of a task.
+	 * Tasks are removed 1 week after receiving their last update.
+	 *
+	 * @param int $id The id of the task
+	 *
+	 * @return FileDisplayResponse<Http::STATUS_OK, array{'Content-Type': string}>|DataResponse<Http::STATUS_NOT_FOUND|Http::STATUS_INTERNAL_SERVER_ERROR, array{message: string}, array{}>
+	 *
+	 * 200: Task returned
+	 * 404: Task not found
+	 */
+	#[PublicPage]
+	public function getImage(int $id): DataResponse|FileDisplayResponse {
+		try {
+			$task = $this->textToImageManager->getUserTask($id, $this->userId);
+			try {
+				$folder = $this->appData->getFolder('text2image');
+			} catch(\OCP\Files\NotFoundException) {
+				$folder = $this->appData->newFolder('text2image');
+			}
+			$file = $folder->getFile((string)$task->getId());
+			$info = getimagesizefromstring($file->getContent());
+
+			return new FileDisplayResponse($file, Http::STATUS_OK, ['Content-Type' => image_type_to_mime_type($info[2])]);
+		} catch (TaskNotFoundException) {
+			return new DataResponse(['message' => $this->l->t('Task not found')], Http::STATUS_NOT_FOUND);
+		} catch (\RuntimeException) {
+			return new DataResponse(['message' => $this->l->t('Internal error')], Http::STATUS_INTERNAL_SERVER_ERROR);
+		} catch (\OCP\Files\NotFoundException) {
+			return new DataResponse(['message' => $this->l->t('Image not found')], Http::STATUS_NOT_FOUND);
+		}
+	}
+
+	/**
+	 * This endpoint allows to delete a scheduled task for a user
+	 *
+	 * @param int $id The id of the task
+	 *
+	 * @return DataResponse<Http::STATUS_OK, array{task: CoreTextToImageTask}, array{}>|DataResponse<Http::STATUS_NOT_FOUND|Http::STATUS_INTERNAL_SERVER_ERROR, array{message: string}, array{}>
+	 *
+	 * 200: Task returned
+	 * 404: Task not found
+	 */
+	#[NoAdminRequired]
+	public function deleteTask(int $id): DataResponse {
+		try {
+			$task = $this->textToImageManager->getUserTask($id, $this->userId);
+
+			$this->textToImageManager->deleteTask($task);
+
+			$json = $task->jsonSerialize();
+
+			return new DataResponse([
+				'task' => $json,
+			]);
+		} catch (TaskNotFoundException $e) {
+			return new DataResponse(['message' => $this->l->t('Task not found')], Http::STATUS_NOT_FOUND);
+		} catch (\RuntimeException $e) {
+			return new DataResponse(['message' => $this->l->t('Internal error')], Http::STATUS_INTERNAL_SERVER_ERROR);
+		}
+	}
+
+
+	/**
+	 * This endpoint returns a list of tasks of a user that are related
+	 * with a specific appId and optionally with an identifier
+	 *
+	 * @param string $appId ID of the app
+	 * @param string|null $identifier An arbitrary identifier for the task
+	 * @return DataResponse<Http::STATUS_OK, array{tasks: CoreTextToImageTask[]}, array{}>|DataResponse<Http::STATUS_INTERNAL_SERVER_ERROR, array{message: string}, array{}>
+	 *
+	 *  200: Task list returned
+	 */
+	#[NoAdminRequired]
+	public function listTasksByApp(string $appId, ?string $identifier = null): DataResponse {
+		try {
+			$tasks = $this->textToImageManager->getUserTasksByApp($this->userId, $appId, $identifier);
+			/** @var CoreTextToImageTask[] $json */
+			$json = array_map(static function (Task $task) {
+				return $task->jsonSerialize();
+			}, $tasks);
+
+			return new DataResponse([
+				'tasks' => $json,
+			]);
+		} catch (\RuntimeException $e) {
+			return new DataResponse(['message' => $this->l->t('Internal error')], Http::STATUS_INTERNAL_SERVER_ERROR);
+		}
+	}
+}

core/Migrations/Version28000Date20230906104802.php

@@ -0,0 +1,100 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * @copyright Copyright (c) 2023 Marcel Klehr <mklehr@gmx.net>
+ *
+ * @author Marcel Klehr <mklehr@gmx.net>
+ *
+ * @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\Core\Migrations;
+
+use Closure;
+use OCP\DB\ISchemaWrapper;
+use OCP\DB\Types;
+use OCP\Migration\IOutput;
+use OCP\Migration\SimpleMigrationStep;
+
+/**
+ * Introduce text2image_tasks table
+ */
+class Version28000Date20230906104802 extends SimpleMigrationStep {
+	/**
+	 * @param IOutput $output
+	 * @param Closure $schemaClosure The `\Closure` returns a `ISchemaWrapper`
+	 * @param array $options
+	 * @return null|ISchemaWrapper
+	 */
+	public function changeSchema(IOutput $output, Closure $schemaClosure, array $options): ?ISchemaWrapper {
+		/** @var ISchemaWrapper $schema */
+		$schema = $schemaClosure();
+		$changed = false;
+		if (!$schema->hasTable('text2image_tasks')) {
+			$table = $schema->createTable('text2image_tasks');
+
+			$table->addColumn('id', Types::BIGINT, [
+				'notnull' => true,
+				'length' => 64,
+				'autoincrement' => true,
+			]);
+			$table->addColumn('input', Types::TEXT, [
+				'notnull' => true,
+			]);
+			$table->addColumn('status', Types::INTEGER, [
+				'notnull' => false,
+				'length' => 6,
+				'default' => 0,
+			]);
+			$table->addColumn('user_id', Types::STRING, [
+				'notnull' => false,
+				'length' => 64,
+			]);
+			$table->addColumn('app_id', Types::STRING, [
+				'notnull' => true,
+				'length' => 32,
+				'default' => '',
+			]);
+			$table->addColumn('identifier', Types::STRING, [
+				'notnull' => true,
+				'length' => 255,
+				'default' => '',
+			]);
+			$table->addColumn('last_updated', Types::INTEGER, [
+				'notnull' => false,
+				'length' => 4,
+				'default' => 0,
+				'unsigned' => true,
+			]);
+
+			$table->setPrimaryKey(['id'], 't2i_tasks_id_index');
+			$table->addIndex(['last_updated'], 't2i_tasks_updated');
+			$table->addIndex(['status'], 't2i_tasks_status');
+			$table->addIndex(['user_id', 'app_id', 'identifier'], 't2i_tasks_uid_appid_ident');
+
+			$changed = true;
+		}
+
+		if ($changed) {
+			return $schema;
+		}
+
+		return null;
+	}
+}

core/ResponseDefinitions.php

@@ -144,6 +144,15 @@ namespace OCA\Core;
  *     output: ?string,
  *     identifier: string,
  * }
+ *
+ * @psalm-type CoreTextToImageTask = array{
+ *      id: ?int,
+ *      status: 0|1|2|3|4,
+ *      userId: ?string,
+ *      appId: string,
+ *      input: string,
+ *      identifier: string,
+ *  }
  */
 class ResponseDefinitions {
 }

lib/private/AppFramework/Bootstrap/RegistrationContext.php

@@ -137,6 +137,12 @@ class RegistrationContext {
 	/** @var ServiceRegistration<IReferenceProvider>[] */
 	private array $referenceProviders = [];
 
+	/** @var ServiceRegistration<\OCP\TextToImage\IProvider>[] */
+	private $textToImageProviders = [];
+
+
+
+
 	/** @var ParameterRegistration[] */
 	private $sensitiveMethods = [];
 
@@ -270,6 +276,13 @@ class RegistrationContext {
 				);
 			}
 
+			public function registerTextToImageProvider(string $providerClass): void {
+				$this->context->registerTextToImageProvider(
+					$this->appId,
+					$providerClass
+				);
+			}
+
 			public function registerTemplateProvider(string $providerClass): void {
 				$this->context->registerTemplateProvider(
 					$this->appId,
@@ -440,6 +453,10 @@ class RegistrationContext {
 		$this->textProcessingProviders[] = new ServiceRegistration($appId, $class);
 	}
 
+	public function registerTextToImageProvider(string $appId, string $class): void {
+		$this->textToImageProviders[] = new ServiceRegistration($appId, $class);
+	}
+
 	public function registerTemplateProvider(string $appId, string $class): void {
 		$this->templateProviders[] = new ServiceRegistration($appId, $class);
 	}
@@ -722,6 +739,13 @@ class RegistrationContext {
 		return $this->textProcessingProviders;
 	}
 
+	/**
+	 * @return ServiceRegistration<\OCP\TextToImage\IProvider>[]
+	 */
+	public function getTextToImageProviders(): array {
+		return $this->textToImageProviders;
+	}
+
 	/**
 	 * @return ServiceRegistration<ICustomTemplateProvider>[]
 	 */

lib/private/Repair/AddRemoveOldTasksBackgroundJob.php

@@ -25,7 +25,8 @@ declare(strict_types=1);
  */
 namespace OC\Repair;
 
-use OC\TextProcessing\RemoveOldTasksBackgroundJob;
+use OC\TextProcessing\RemoveOldTasksBackgroundJob as RemoveOldTextProcessingTasksBackgroundJob;
+use OC\TextToImage\RemoveOldTasksBackgroundJob as RemoveOldTextToImageTasksBackgroundJob;
 use OCP\BackgroundJob\IJobList;
 use OCP\Migration\IOutput;
 use OCP\Migration\IRepairStep;
@@ -38,10 +39,11 @@ class AddRemoveOldTasksBackgroundJob implements IRepairStep {
 	}
 
 	public function getName(): string {
-		return 'Add language model tasks cleanup job';
+		return 'Add AI tasks cleanup job';
 	}
 
 	public function run(IOutput $output) {
-		$this->jobList->add(RemoveOldTasksBackgroundJob::class);
+		$this->jobList->add(RemoveOldTextProcessingTasksBackgroundJob::class);
+		$this->jobList->add(RemoveOldTextToImageTasksBackgroundJob::class);
 	}
 }

lib/private/TextToImage/Db/Task.php

@@ -0,0 +1,119 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * @copyright Copyright (c) 2023 Marcel Klehr <mklehr@gmx.net>
+ *
+ * @author Marcel Klehr <mklehr@gmx.net>
+ *
+ * @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\TextToImage\Db;
+
+use OCP\AppFramework\Db\Entity;
+use OCP\Files\AppData\IAppDataFactory;
+use OCP\Files\NotFoundException;
+use OCP\Files\NotPermittedException;
+use OCP\Image;
+use OCP\TextToImage\Task as OCPTask;
+
+/**
+ * @method setLastUpdated(int $lastUpdated)
+ * @method int getLastUpdated()
+ * @method setInput(string $type)
+ * @method string getInput()
+ * @method setResultPath(string $resultPath)
+ * @method string getResultPath()
+ * @method setStatus(int $type)
+ * @method int getStatus()
+ * @method setUserId(?string $userId)
+ * @method string|null getUserId()
+ * @method setAppId(string $type)
+ * @method string getAppId()
+ * @method setIdentifier(string $identifier)
+ * @method string getIdentifier()
+ */
+class Task extends Entity {
+	protected $lastUpdated;
+	protected $type;
+	protected $input;
+	protected $status;
+	protected $userId;
+	protected $appId;
+	protected $identifier;
+
+	/**
+	 * @var string[]
+	 */
+	public static array $columns = ['id', 'last_updated', 'input', 'status', 'user_id', 'app_id', 'identifier'];
+
+	/**
+	 * @var string[]
+	 */
+	public static array $fields = ['id', 'lastUpdated', 'input', 'status', 'userId', 'appId', 'identifier'];
+
+
+	public function __construct() {
+		// add types in constructor
+		$this->addType('id', 'integer');
+		$this->addType('lastUpdated', 'integer');
+		$this->addType('input', 'string');
+		$this->addType('status', 'integer');
+		$this->addType('userId', 'string');
+		$this->addType('appId', 'string');
+		$this->addType('identifier', 'string');
+	}
+
+	public function toRow(): array {
+		return array_combine(self::$columns, array_map(function ($field) {
+			return $this->{'get'.ucfirst($field)}();
+		}, self::$fields));
+	}
+
+	public static function fromPublicTask(OCPTask $task): Task {
+		/** @var Task $dbTask */
+		$dbTask = Task::fromParams([
+			'id' => $task->getId(),
+			'lastUpdated' => time(),
+			'status' => $task->getStatus(),
+			'input' => $task->getInput(),
+			'userId' => $task->getUserId(),
+			'appId' => $task->getAppId(),
+			'identifier' => $task->getIdentifier(),
+		]);
+		return $dbTask;
+	}
+
+	public function toPublicTask(): OCPTask {
+		$task = new OCPTask($this->getInput(), $this->getAppId(), $this->getuserId(), $this->getIdentifier());
+		$task->setId($this->getId());
+		$task->setStatus($this->getStatus());
+		$appData = \OC::$server->get(IAppDataFactory::class)->get('core');
+		try {
+			try {
+				$folder = $appData->getFolder('text2image');
+			} catch(NotFoundException) {
+				$folder = $appData->newFolder('text2image');
+			}
+			$task->setOutputImage(new Image(base64_encode($folder->getFile((string)$task->getId())->getContent())));
+		} catch (NotFoundException|NotPermittedException) {
+			// noop
+		}
+		return $task;
+	}
+}

lib/private/TextToImage/Db/TaskMapper.php

@@ -0,0 +1,118 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * @copyright Copyright (c) 2023 Marcel Klehr <mklehr@gmx.net>
+ *
+ * @author Marcel Klehr <mklehr@gmx.net>
+ *
+ * @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\TextToImage\Db;
+
+use OCP\AppFramework\Db\DoesNotExistException;
+use OCP\AppFramework\Db\Entity;
+use OCP\AppFramework\Db\MultipleObjectsReturnedException;
+use OCP\AppFramework\Db\QBMapper;
+use OCP\AppFramework\Utility\ITimeFactory;
+use OCP\DB\Exception;
+use OCP\IDBConnection;
+
+/**
+ * @extends QBMapper<Task>
+ */
+class TaskMapper extends QBMapper {
+	public function __construct(
+		IDBConnection $db,
+		private ITimeFactory $timeFactory,
+	) {
+		parent::__construct($db, 'text2image_tasks', Task::class);
+	}
+
+	/**
+	 * @param int $id
+	 * @return Task
+	 * @throws Exception
+	 * @throws DoesNotExistException
+	 * @throws MultipleObjectsReturnedException
+	 */
+	public function find(int $id): Task {
+		$qb = $this->db->getQueryBuilder();
+		$qb->select(Task::$columns)
+			->from($this->tableName)
+			->where($qb->expr()->eq('id', $qb->createPositionalParameter($id)));
+		return $this->findEntity($qb);
+	}
+
+	/**
+	 * @param int $id
+	 * @param string|null $userId
+	 * @return Task
+	 * @throws DoesNotExistException
+	 * @throws Exception
+	 * @throws MultipleObjectsReturnedException
+	 */
+	public function findByIdAndUser(int $id, ?string $userId): Task {
+		$qb = $this->db->getQueryBuilder();
+		$qb->select(Task::$columns)
+			->from($this->tableName)
+			->where($qb->expr()->eq('id', $qb->createPositionalParameter($id)));
+		if ($userId === null) {
+			$qb->andWhere($qb->expr()->isNull('user_id'));
+		} else {
+			$qb->andWhere($qb->expr()->eq('user_id', $qb->createPositionalParameter($userId)));
+		}
+		return $this->findEntity($qb);
+	}
+
+	/**
+	 * @param string $userId
+	 * @param string $appId
+	 * @param string|null $identifier
+	 * @return array
+	 * @throws Exception
+	 */
+	public function findUserTasksByApp(string $userId, string $appId, ?string $identifier = null): array {
+		$qb = $this->db->getQueryBuilder();
+		$qb->select(Task::$columns)
+			->from($this->tableName)
+			->where($qb->expr()->eq('user_id', $qb->createPositionalParameter($userId)))
+			->andWhere($qb->expr()->eq('app_id', $qb->createPositionalParameter($appId)));
+		if ($identifier !== null) {
+			$qb->andWhere($qb->expr()->eq('identifier', $qb->createPositionalParameter($identifier)));
+		}
+		return $this->findEntities($qb);
+	}
+
+	/**
+	 * @param int $timeout
+	 * @return int the number of deleted tasks
+	 * @throws Exception
+	 */
+	public function deleteOlderThan(int $timeout): int {
+		$qb = $this->db->getQueryBuilder();
+		$qb->delete($this->tableName)
+			->where($qb->expr()->lt('last_updated', $qb->createPositionalParameter(time() - $timeout)));
+		return $qb->executeStatement();
+	}
+
+	public function update(Entity $entity): Entity {
+		$entity->setLastUpdated($this->timeFactory->now()->getTimestamp());
+		return parent::update($entity);
+	}
+}

lib/private/TextToImage/Manager.php

@@ -0,0 +1,245 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * @copyright Copyright (c) 2023 Marcel Klehr <mklehr@gmx.net>
+ *
+ * @author Marcel Klehr <mklehr@gmx.net>
+ *
+ * @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\TextToImage;
+
+use OC\AppFramework\Bootstrap\Coordinator;
+use OC\TextToImage\Db\Task as DbTask;
+use OCP\Files\AppData\IAppDataFactory;
+use OCP\Files\IAppData;
+use OCP\IConfig;
+use OCP\TextToImage\Exception\TaskNotFoundException;
+use OCP\TextToImage\IManager;
+use OCP\TextToImage\Task;
+use OC\TextToImage\Db\TaskMapper;
+use OCP\AppFramework\Db\DoesNotExistException;
+use OCP\AppFramework\Db\MultipleObjectsReturnedException;
+use OCP\BackgroundJob\IJobList;
+use OCP\DB\Exception;
+use OCP\IServerContainer;
+use OCP\TextToImage\IProvider;
+use OCP\PreConditionNotMetException;
+use Psr\Log\LoggerInterface;
+use RuntimeException;
+use Throwable;
+
+class Manager implements IManager {
+	/** @var ?IProvider[] */
+	private ?array $providers = null;
+	private IAppData $appData;
+
+	public function __construct(
+		private IServerContainer $serverContainer,
+		private Coordinator $coordinator,
+		private LoggerInterface $logger,
+		private IJobList $jobList,
+		private TaskMapper $taskMapper,
+		private IConfig $config,
+		private IAppDataFactory $appDataFactory,
+	) {
+		$this->appData = $this->appDataFactory->get('core');
+	}
+
+	public function getProviders(): array {
+		$context = $this->coordinator->getRegistrationContext();
+		if ($context === null) {
+			return [];
+		}
+
+		if ($this->providers !== null) {
+			return $this->providers;
+		}
+
+		$this->providers = [];
+
+		foreach ($context->getTextToImageProviders() as $providerServiceRegistration) {
+			$class = $providerServiceRegistration->getService();
+			try {
+				$this->providers[$class] = $this->serverContainer->get($class);
+			} catch (Throwable $e) {
+				$this->logger->error('Failed to load Text to image provider ' . $class, [
+					'exception' => $e,
+				]);
+			}
+		}
+
+		return $this->providers;
+	}
+
+	public function hasProviders(): bool {
+		$context = $this->coordinator->getRegistrationContext();
+		if ($context === null) {
+			return false;
+		}
+		return count($context->getTextToImageProviders()) > 0;
+	}
+
+	/**
+	 * @inheritDoc
+	 */
+	public function runTask(Task $task): void {
+		if (!$this->hasProviders()) {
+			throw new PreConditionNotMetException('No text to image provider is installed that can handle this task');
+		}
+		$providers = $this->getProviders();
+
+		$json = $this->config->getAppValue('core', 'ai.text2image_provider', '');
+		if ($json !== '') {
+			$className = json_decode($json, true);
+			$provider = current(array_filter($providers, fn ($provider) => $provider::class === $className));
+			if ($provider !== false) {
+				$providers = [$provider];
+			}
+		}
+
+		foreach ($providers as $provider) {
+			try {
+				$task->setStatus(Task::STATUS_RUNNING);
+				if ($task->getId() === null) {
+					$taskEntity = $this->taskMapper->insert(DbTask::fromPublicTask($task));
+					$task->setId($taskEntity->getId());
+				} else {
+					$this->taskMapper->update(DbTask::fromPublicTask($task));
+				}
+				try {
+					$folder = $this->appData->getFolder('text2image');
+				} catch(\OCP\Files\NotFoundException $e) {
+					$folder = $this->appData->newFolder('text2image');
+				}
+				$file = $folder->newFile((string) $task->getId());
+				$provider->generate($task->getInput(), $file->write());
+				$task->setResultPath($file->getName());
+				$task->setStatus(Task::STATUS_SUCCESSFUL);
+				$this->taskMapper->update(DbTask::fromPublicTask($task));
+				return;
+			} catch (\RuntimeException $e) {
+				$this->logger->info('Text2Image generation using provider ' . $provider->getName() . ' failed', ['exception' => $e]);
+				$task->setStatus(Task::STATUS_FAILED);
+				$this->taskMapper->update(DbTask::fromPublicTask($task));
+				throw $e;
+			} catch (\Throwable $e) {
+				$this->logger->info('Text2Image generation using provider ' . $provider->getName() . ' failed', ['exception' => $e]);
+				$task->setStatus(Task::STATUS_FAILED);
+				$this->taskMapper->update(DbTask::fromPublicTask($task));
+				throw new RuntimeException('Text2Image generation using provider ' . $provider->getName() . ' failed: ' . $e->getMessage(), 0, $e);
+			}
+		}
+
+		throw new RuntimeException('Could not run task');
+	}
+
+	/**
+	 * @inheritDoc
+	 * @throws Exception
+	 */
+	public function scheduleTask(Task $task): void {
+		if (!$this->hasProviders()) {
+			throw new PreConditionNotMetException('No text to image provider is installed that can handle this task');
+		}
+		$task->setStatus(Task::STATUS_SCHEDULED);
+		$taskEntity = DbTask::fromPublicTask($task);
+		$this->taskMapper->insert($taskEntity);
+		$task->setId($taskEntity->getId());
+		$this->jobList->add(TaskBackgroundJob::class, [
+			'taskId' => $task->getId()
+		]);
+	}
+
+	/**
+	 * @inheritDoc
+	 */
+	public function deleteTask(Task $task): void {
+		$taskEntity = DbTask::fromPublicTask($task);
+		$this->taskMapper->delete($taskEntity);
+		$this->jobList->remove(TaskBackgroundJob::class, [
+			'taskId' => $task->getId()
+		]);
+	}
+
+	/**
+	 * Get a task from its id
+	 *
+	 * @param int $id The id of the task
+	 * @return Task
+	 * @throws RuntimeException If the query failed
+	 * @throws NotFoundException If the task could not be found
+	 */
+	public function getTask(int $id): Task {
+		try {
+			$taskEntity = $this->taskMapper->find($id);
+			return $taskEntity->toPublicTask();
+		} catch (DoesNotExistException $e) {
+			throw new TaskNotFoundException('Could not find task with the provided id');
+		} catch (MultipleObjectsReturnedException $e) {
+			throw new RuntimeException('Could not uniquely identify task with given id', 0, $e);
+		} catch (Exception $e) {
+			throw new RuntimeException('Failure while trying to find task by id: ' . $e->getMessage(), 0, $e);
+		}
+	}
+
+	/**
+	 * Get a task from its user id and task id
+	 * If userId is null, this can only get a task that was scheduled anonymously
+	 *
+	 * @param int $id The id of the task
+	 * @param string|null $userId The user id that scheduled the task
+	 * @return Task
+	 * @throws RuntimeException If the query failed
+	 * @throws NotFoundException If the task could not be found
+	 */
+	public function getUserTask(int $id, ?string $userId): Task {
+		try {
+			$taskEntity = $this->taskMapper->findByIdAndUser($id, $userId);
+			return $taskEntity->toPublicTask();
+		} catch (DoesNotExistException $e) {
+			throw new TaskNotFoundException('Could not find task with the provided id and user id');
+		} catch (MultipleObjectsReturnedException $e) {
+			throw new RuntimeException('Could not uniquely identify task with given id and user id', 0, $e);
+		} catch (Exception $e) {
+			throw new RuntimeException('Failure while trying to find task by id and user id: ' . $e->getMessage(), 0, $e);
+		}
+	}
+
+	/**
+	 * Get a list of tasks scheduled by a specific user for a specific app
+	 * and optionally with a specific identifier.
+	 * This cannot be used to get anonymously scheduled tasks
+	 *
+	 * @param string $userId
+	 * @param string $appId
+	 * @param string|null $identifier
+	 * @return array
+	 */
+	public function getUserTasksByApp(string $userId, string $appId, ?string $identifier = null): array {
+		try {
+			$taskEntities = $this->taskMapper->findUserTasksByApp($userId, $appId, $identifier);
+			return array_map(static function (DbTask $taskEntity) {
+				return $taskEntity->toPublicTask();
+			}, $taskEntities);
+		} catch (Exception $e) {
+			throw new RuntimeException('Failure while trying to find tasks by appId and identifier: ' . $e->getMessage(), 0, $e);
+		}
+	}
+}

lib/private/TextToImage/RemoveOldTasksBackgroundJob.php

@@ -0,0 +1,59 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * @copyright Copyright (c) 2023 Marcel Klehr <mklehr@gmx.net>
+ *
+ * @author Marcel Klehr <mklehr@gmx.net>
+ *
+ * @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\TextToImage;
+
+use OC\TextToImage\Db\TaskMapper;
+use OCP\AppFramework\Utility\ITimeFactory;
+use OCP\BackgroundJob\TimedJob;
+use OCP\DB\Exception;
+use Psr\Log\LoggerInterface;
+
+class RemoveOldTasksBackgroundJob extends TimedJob {
+	public const MAX_TASK_AGE_SECONDS = 60 * 50 * 24 * 7; // 1 week
+
+	public function __construct(
+		ITimeFactory $timeFactory,
+		private TaskMapper $taskMapper,
+		private LoggerInterface $logger,
+
+	) {
+		parent::__construct($timeFactory);
+		$this->setInterval(60 * 60 * 24);
+	}
+
+	/**
+	 * @param mixed $argument
+	 * @inheritDoc
+	 */
+	protected function run($argument) {
+		try {
+			$this->taskMapper->deleteOlderThan(self::MAX_TASK_AGE_SECONDS);
+		} catch (Exception $e) {
+			$this->logger->warning('Failed to delete stale text to image tasks', ['exception' => $e]);
+		}
+	}
+}

lib/private/TextToImage/TaskBackgroundJob.php

@@ -0,0 +1,63 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * @copyright Copyright (c) 2023 Marcel Klehr <mklehr@gmx.net>
+ *
+ * @author Marcel Klehr <mklehr@gmx.net>
+ *
+ * @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\TextToImage;
+
+use OCP\AppFramework\Utility\ITimeFactory;
+use OCP\BackgroundJob\QueuedJob;
+use OCP\EventDispatcher\IEventDispatcher;
+use OCP\TextToImage\Events\TaskFailedEvent;
+use OCP\TextToImage\Events\TaskSuccessfulEvent;
+use OCP\TextToImage\IManager;
+
+class TaskBackgroundJob extends QueuedJob {
+	public function __construct(
+		ITimeFactory             $timeFactory,
+		private IManager         $text2imageManager,
+		private IEventDispatcher $eventDispatcher,
+	) {
+		parent::__construct($timeFactory);
+		// We want to avoid overloading the machine with these jobs
+		// so we only allow running one job at a time
+		$this->setAllowParallelRuns(false);
+	}
+
+	/**
+	 * @param array{taskId: int} $argument
+	 * @inheritDoc
+	 */
+	protected function run($argument) {
+		$taskId = $argument['taskId'];
+		$task = $this->text2imageManager->getTask($taskId);
+		try {
+			$this->text2imageManager->runTask($task);
+			$event = new TaskSuccessfulEvent($task);
+		} catch (\Throwable $e) {
+			$event = new TaskFailedEvent($task, $e->getMessage());
+		}
+		$this->eventDispatcher->dispatchTyped($event);
+	}
+}

lib/public/TextToImage/Events/AbstractTextToImageEvent.php

@@ -0,0 +1,52 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * @copyright Copyright (c) 2023 Marcel Klehr <mklehr@gmx.net>
+ *
+ * @author Marcel Klehr <mklehr@gmx.net>
+ *
+ * @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 OCP\TextToImage\Events;
+
+use OCP\EventDispatcher\Event;
+use OCP\TextToImage\Task;
+
+/**
+ * @since 28.0.0
+ */
+abstract class AbstractTextToImageEvent extends Event {
+	/**
+	 * @since 28.0.0
+	 */
+	public function __construct(
+		private Task $task
+	) {
+		parent::__construct();
+	}
+
+	/**
+	 * @return Task
+	 * @since 28.0.0
+	 */
+	public function getTask(): Task {
+		return $this->task;
+	}
+}

lib/public/TextToImage/Events/TaskFailedEvent.php

@@ -0,0 +1,54 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * @copyright Copyright (c) 2023 Marcel Klehr <mklehr@gmx.net>
+ *
+ * @author Marcel Klehr <mklehr@gmx.net>
+ *
+ * @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 OCP\TextToImage\Events;
+
+use OCP\TextToImage\Task;
+
+/**
+ * @since 28.0.0
+ */
+class TaskFailedEvent extends AbstractTextToImageEvent {
+	/**
+	 * @param Task $task
+	 * @param string $errorMessage
+	 * @since 28.0.0
+	 */
+	public function __construct(
+		Task $task,
+		private string $errorMessage,
+	) {
+		parent::__construct($task);
+	}
+
+	/**
+	 * @return string
+	 * @since 28.0.0
+	 */
+	public function getErrorMessage(): string {
+		return $this->errorMessage;
+	}
+}

lib/public/TextToImage/Events/TaskSuccessfulEvent.php

@@ -0,0 +1,33 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * @copyright Copyright (c) 2023 Marcel Klehr <mklehr@gmx.net>
+ *
+ * @author Marcel Klehr <mklehr@gmx.net>
+ *
+ * @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 OCP\TextToImage\Events;
+
+/**
+ * @since 27.1.0
+ */
+class TaskSuccessfulEvent extends AbstractTextToImageEvent {
+}

lib/public/TextToImage/Exception/Exception.php

@@ -0,0 +1,29 @@
+<?php
+
+/**
+ * @copyright Copyright (c) 2023 Marcel Klehr <mklehr@gmx.net>
+ *
+ * @author Marcel Klehr <mklehr@gmx.net>
+ *
+ * @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 OCP\TextToImage\Exception;
+
+class Exception extends \Exception {
+
+}

lib/public/TextToImage/Exception/TaskNotFoundException.php

@@ -0,0 +1,29 @@
+<?php
+
+/**
+ * @copyright Copyright (c) 2023 Marcel Klehr <mklehr@gmx.net>
+ *
+ * @author Marcel Klehr <mklehr@gmx.net>
+ *
+ * @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 OCP\TextToImage\Exception;
+
+class TaskNotFoundException extends Exception {
+
+}

lib/public/TextToImage/IManager.php

@@ -0,0 +1,98 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * @copyright Copyright (c) 2023 Marcel Klehr <mklehr@gmx.net>
+ *
+ * @author Marcel Klehr <mklehr@gmx.net>
+ *
+ * @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 OCP\TextToImage;
+
+use OCP\PreConditionNotMetException;
+use OCP\TextToImage\Exception\TaskNotFoundException;
+use RuntimeException;
+
+/**
+ * API surface for apps interacting with and making use of TextToImage providers
+ * without knowing which providers are installed
+ * @since 28.0.0
+ */
+interface IManager {
+	/**
+	 * @since 28.0.0
+	 */
+	public function hasProviders(): bool;
+
+	/**
+	 * @param Task $task The task to run
+	 * @throws PreConditionNotMetException If no or not the requested provider was registered but this method was still called
+	 * @throws RuntimeException If something else failed
+	 * @since 28.0.0
+	 */
+	public function runTask(Task $task): void;
+
+	/**
+	 * Will schedule a TextToImage process in the background. The result will become available
+	 * with the \OCP\TextToImage\TaskSuccessfulEvent
+	 * If inference fails a \OCP\TextToImage\Events\TaskFailedEvent will be dispatched instead
+	 *
+	 * @param Task $task The task to schedule
+	 * @throws PreConditionNotMetException If no or not the requested provider was registered but this method was still called
+	 * @since 28.0.0
+	 */
+	public function scheduleTask(Task $task) : void;
+
+	/**
+	 * Delete a task that has been scheduled before
+	 *
+	 * @param Task $task The task to delete
+	 * @since 28.0.0
+	 */
+	public function deleteTask(Task $task): void;
+
+	/**
+	 * @param int $id The id of the task
+	 * @return Task
+	 * @throws RuntimeException If the query failed
+	 * @throws TaskNotFoundException If the task could not be found
+	 * @since 28.0.0
+	 */
+	public function getTask(int $id): Task;
+
+	/**
+	 * @param int $id The id of the task
+	 * @param string|null $userId The user id that scheduled the task
+	 * @return Task
+	 * @throws RuntimeException If the query failed
+	 * @throws TaskNotFoundException If the task could not be found
+	 * @since 28.0.0
+	 */
+	public function getUserTask(int $id, ?string $userId): Task;
+
+	/**
+	 * @param string $userId
+	 * @param string $appId
+	 * @param string|null $identifier
+	 * @return array
+	 * @since 28.0.0
+	 */
+	public function getUserTasksByApp(string $userId, string $appId, ?string $identifier = null): array;
+}

lib/public/TextToImage/IProvider.php

@@ -0,0 +1,52 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * @copyright Copyright (c) 2023 Marcel Klehr <mklehr@gmx.net>
+ *
+ * @author Marcel Klehr <mklehr@gmx.net>
+ *
+ * @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 OCP\TextToImage;
+
+use RuntimeException;
+
+/**
+ * This is the interface that is implemented by apps that
+ * implement a text to image provider
+ * @since 28.0.0
+ */
+interface IProvider {
+	/**
+	 * The localized name of this provider
+	 * @since 28.0.0
+	 */
+	public function getName(): string;
+
+	/**
+	 * Processes a text
+	 *
+	 * @param string $prompt The input text
+	 * @param resource $resource The file resource to write the image to
+	 * @return void
+	 * @since 28.0.0
+	 * @throws RuntimeException If the text could not be processed
+	 */
+	public function generate(string $prompt, $resource): void;
+}

lib/public/TextToImage/Task.php

@@ -0,0 +1,179 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * @copyright Copyright (c) 2023 Marcel Klehr <mklehr@gmx.net>
+ *
+ * @author Marcel Klehr <mklehr@gmx.net>
+ *
+ * @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 OCP\TextToImage;
+
+use OCP\IImage;
+use OCP\Image;
+use OCP\TextProcessing\IProvider as P;
+use OCP\TextProcessing\ITaskType;
+
+/**
+ * This is a text to image task
+ *
+ * @since 28.0.0
+ */
+final class Task implements \JsonSerializable {
+	protected ?int $id = null;
+
+	private ?IImage $image = null;
+
+	/**
+	 * @since 28.0.0
+	 */
+	public const STATUS_FAILED = 4;
+	/**
+	 * @since 28.0.0
+	 */
+	public const STATUS_SUCCESSFUL = 3;
+	/**
+	 * @since 28.0.0
+	 */
+	public const STATUS_RUNNING = 2;
+	/**
+	 * @since 28.0.0
+	 */
+	public const STATUS_SCHEDULED = 1;
+	/**
+	 * @since 28.0.0
+	 */
+	public const STATUS_UNKNOWN = 0;
+
+	/**
+	 * @psalm-var self::STATUS_*
+	 */
+	protected int $status = self::STATUS_UNKNOWN;
+
+	/**
+	 * @param string $input
+	 * @param string $appId
+	 * @param string|null $userId
+	 * @param string $identifier An arbitrary identifier for this task. max length: 255 chars
+	 * @since 28.0.0
+	 */
+	final public function __construct(
+		protected string $input,
+		protected string $appId,
+		protected ?string $userId,
+		protected string $identifier = '',
+	) {
+	}
+
+	/**
+	 * @return IImage|null
+	 * @since 28.0.0
+	 */
+	final public function getOutputImage(): ?IImage {
+		return $this->image;
+	}
+
+	/**
+	 * @param IImage|null $image
+	 * @since 28.0.0
+	 */
+	final public function setOutputImage(?IImage $image): void {
+		$this->image = $image;
+	}
+
+	/**
+	 * @psalm-return self::STATUS_*
+	 * @since 28.0.0
+	 */
+	final public function getStatus(): int {
+		return $this->status;
+	}
+
+	/**
+	 * @psalm-param self::STATUS_* $status
+	 * @since 28.0.0
+	 */
+	final public function setStatus(int $status): void {
+		$this->status = $status;
+	}
+
+	/**
+	 * @return int|null
+	 * @since 28.0.0
+	 */
+	final public function getId(): ?int {
+		return $this->id;
+	}
+
+	/**
+	 * @param int|null $id
+	 * @since 28.0.0
+	 */
+	final public function setId(?int $id): void {
+		$this->id = $id;
+	}
+
+	/**
+	 * @return string
+	 * @since 28.0.0
+	 */
+	final public function getInput(): string {
+		return $this->input;
+	}
+
+	/**
+	 * @return string
+	 * @since 28.0.0
+	 */
+	final public function getAppId(): string {
+		return $this->appId;
+	}
+
+	/**
+	 * @return string
+	 * @since 28.0.0
+	 */
+	final public function getIdentifier(): string {
+		return $this->identifier;
+	}
+
+	/**
+	 * @return string|null
+	 * @since 28.0.0
+	 */
+	final public function getUserId(): ?string {
+		return $this->userId;
+	}
+
+	/**
+	 * @psalm-return array{id: ?int, status: 0|1|2|3|4, userId: ?string, appId: string, input: string, output: ?string, identifier: string}
+	 * @since 28.0.0
+	 */
+	public function jsonSerialize(): array {
+		return [
+			'id' => $this->getId(),
+			'status' => $this->getStatus(),
+			'userId' => $this->getUserId(),
+			'appId' => $this->getAppId(),
+			'input' => $this->getInput(),
+			'result' => $this->getOutput(),
+			'identifier' => $this->getIdentifier(),
+		];
+	}
+}