feature: mail provider backend

lib/AppInfo/Application.php

@@ -53,6 +53,7 @@
 use OCA\Mail\Listener\SpamReportListener;
 use OCA\Mail\Listener\UserDeletedListener;
 use OCA\Mail\Notification\Notifier;
+use OCA\Mail\Provider\MailProvider;
 use OCA\Mail\Search\FilteringProvider;
 use OCA\Mail\Search\Provider;
 use OCA\Mail\Service\Attachment\AttachmentService;
@@ -156,6 +157,10 @@ public function register(IRegistrationContext $context): void {
 			$context->registerSearchProvider(Provider::class);
 		}
 
+		// Added in version 4.0.0
+		// register mail provider
+		$context->registerMailProvider(MailProvider::class);
+
 		$context->registerNotifierService(Notifier::class);
 
 		// bypass Horde Translation system

lib/Db/MailAccountMapper.php

@@ -83,6 +83,29 @@ public function findByUserId(string $userId): array {
 		return $this->findEntities($query);
 	}
 
+	/**
+	 * Finds a mail account(s) by user id and mail address
+	 *
+	 * @since 4.0.0
+	 *
+	 * @param string $userId			system user id
+	 * @param string $address			mail address (e.g. test@example.com)
+	 *
+	 * @return MailAccount[]
+	 *
+	 * @throws DoesNotExistException
+	 */
+	public function findByUserIdAndAddress(string $userId, string $address): array {
+		$qb = $this->db->getQueryBuilder();
+		$query = $qb
+			->select('*')
+			->from($this->getTableName())
+			->where($qb->expr()->eq('user_id', $qb->createNamedParameter($userId)))
+			->andWhere($qb->expr()->eq('email', $qb->createNamedParameter($address)));
+
+		return $this->findEntities($query);
+	}
+
 	/**
 	 * @throws DoesNotExistException
 	 * @throws MultipleObjectsReturnedException

lib/Provider/Command/MessageSend.php

@@ -0,0 +1,120 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * SPDX-FileCopyrightText: 2024 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+namespace OCA\Mail\Provider\Command;
+
+use OCA\Mail\Db\LocalMessage;
+use OCA\Mail\Service\AccountService;
+use OCA\Mail\Service\Attachment\AttachmentService;
+use OCA\Mail\Service\OutboxService;
+use OCP\AppFramework\Utility\ITimeFactory;
+use OCP\IConfig;
+use OCP\Mail\Provider\Exception\SendException;
+use OCP\Mail\Provider\IAddress;
+use OCP\Mail\Provider\IMessage;
+
+class MessageSend {
+
+	public function __construct(
+		protected IConfig $config,
+		protected ITimeFactory $time,
+		protected AccountService $accountService,
+		protected OutboxService $outboxService,
+		protected AttachmentService $attachmentService
+	) {
+	}
+
+	/**
+	 * performs send operation
+	 *
+	 * @since 4.0.0
+	 *
+	 * @param string $userId			system user id
+	 * @param string $serviceId			mail account id
+	 * @param IMessage $message			mail message object with all required parameters to send a message
+	 * @param array $options			array of options reserved for future use
+	 *
+	 * @return LocalMessage
+	 */
+	public function perform(string $userId, string $serviceId, IMessage $message, array $option = []): LocalMessage {
+		// find user mail account details
+		$account = $this->accountService->find($userId, (int) $serviceId);
+		// convert mail provider message to mail app message
+		$localMessage = new LocalMessage();
+		$localMessage->setType($localMessage::TYPE_OUTGOING);
+		$localMessage->setAccountId($account->getId());
+		$localMessage->setSubject($message->getSubject());
+		$localMessage->setBody($message->getBody());
+		// disabled due to issues caused by opening these messages in gui
+		//$localMessage->setEditorBody($message->getBody());
+		$localMessage->setHtml(true);
+		$localMessage->setSendAt($this->time->getTime());
+
+		// convert all mail provider attachments to local attachments
+		$attachments = [];
+		if (count($message->getAttachments()) > 0) {
+			// iterate attachments and save them
+			foreach ($message->getAttachments() as $entry) {
+				// determine if required parameters are set
+				if (empty($entry->getName()) || empty($entry->getType()) || empty($entry->getContents())) {
+					throw new SendException("Invalid Attachment Parameter: MUST contain values for Name, Type and Contents");
+				}
+				// convert mail provider attachment to mail app attachment
+				$attachments[] = $this->attachmentService->addFileFromString(
+					$userId,
+					$entry->getName(),
+					$entry->getType(),
+					$entry->getContents()
+				)->jsonSerialize();
+			}
+		}
+		// determine if required To address is set
+		if (empty($message->getTo()) || empty($message->getTo()[0]->getAddress())) {
+			throw new SendException("Invalid Message Parameter: MUST contain at least one TO address with a valid address");
+		}
+		// convert recipient addresses
+		$to = $this->convertAddressArray($message->getTo());
+		$cc = $this->convertAddressArray($message->getCc());
+		$bcc = $this->convertAddressArray($message->getBcc());
+		// save message for sending
+		$localMessage = $this->outboxService->saveMessage(
+			$account,
+			$localMessage,
+			$to,
+			$cc,
+			$bcc,
+			$attachments
+		);
+
+		// evaluate if job scheduler is NOT cron, send message right away otherwise let cron job handle it
+		if ($this->config->getAppValue('core', 'backgroundjobs_mode', 'ajax') !== 'cron') {
+			$localMessage = $this->outboxService->sendMessage($localMessage, $account);
+		}
+
+		return $localMessage;
+
+	}
+
+	/**
+	 * Converts IAddress objects collection to plain array
+	 *
+	 * @since 4.0.0
+	 *
+	 * @param array<int,IAddress> $addresses		collection of IAddress objects
+	 *
+	 * @return array<int,array{email: string, label?: string}>
+	 */
+	protected function convertAddressArray(array $addresses): array {
+		return array_map(static function (IAddress $address) {
+			return !empty($address->getLabel())
+				? ['email' => $address->getAddress(), 'label' => $address->getLabel()]
+				: ['email' => $address->getAddress()];
+		}, $addresses);
+	}
+
+}

lib/Provider/MailProvider.php

@@ -0,0 +1,175 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * SPDX-FileCopyrightText: 2024 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+namespace OCA\Mail\Provider;
+
+use OCA\Mail\Account;
+use OCA\Mail\Service\AccountService;
+use OCP\Mail\Provider\Address as MailAddress;
+use OCP\Mail\Provider\IProvider;
+use OCP\Mail\Provider\IService;
+use Psr\Container\ContainerInterface;
+
+class MailProvider implements IProvider {
+
+	private ?array $ServiceCollection = [];
+
+	public function __construct(
+		protected ContainerInterface $container,
+		protected AccountService $accountService
+	) {
+	}
+
+	/**
+	 * arbitrary unique text string identifying this provider
+	 *
+	 * @since 4.0.0
+	 *
+	 * @return string					id of this provider (e.g. UUID or 'IMAP/SMTP' or anything else)
+	 */
+	public function id(): string {
+		return 'mail-application';
+	}
+
+	/**
+	 * localized human friendly name of this provider
+	 *
+	 * @since 4.0.0
+	 *
+	 * @return string					label/name of this provider (e.g. Plain Old IMAP/SMTP)
+	 */
+	public function label(): string {
+		return 'Mail Application';
+	}
+
+	/**
+	 * determine if any services are configured for a specific user
+	 *
+	 * @since 4.0.0
+	 *
+	 * @param string $userId			system user id
+	 *
+	 * @return bool 					true if any services are configure for the user
+	 */
+	public function hasServices(string $userId): bool {
+		return (count($this->listServices($userId)) > 0);
+	}
+
+	/**
+	 * retrieve collection of services for a specific user
+	 *
+	 * @since 4.0.0
+	 *
+	 * @param string $userId			system user id
+	 *
+	 * @return array<string,IService>	collection of service id and object ['1' => IServiceObject]
+	 */
+	public function listServices(string $userId): array {
+
+		try {
+			// retrieve service(s) details from data store
+			$accounts = $this->accountService->findByUserId($userId);
+		} catch (\Throwable $th) {
+			return [];
+		}
+		// construct temporary collection
+		$services = [];
+		// add services to collection
+		foreach ($accounts as $entry) {
+			// extract values
+			$serviceId = (string) $entry->getId();
+			$label = $entry->getName();
+			$address = new MailAddress($entry->getEmail(), $entry->getName());
+			// add service to collection
+			$services[$serviceId] = new MailService($this->container, $userId, $serviceId, $label, $address);
+		}
+		// return list of services for user
+		return $services;
+
+	}
+
+	/**
+	 * retrieve a service with a specific id
+	 *
+	 * @since 4.0.0
+	 *
+	 * @param string $userId			system user id
+	 * @param string $serviceId			mail account id
+	 *
+	 * @return IService|null            returns service object or null if none found
+	 *
+	 */
+	public function findServiceById(string $userId, string $serviceId): IService | null {
+
+		// determine if a valid user and service id was submitted
+		if (empty($userId) && !ctype_digit($serviceId)) {
+			return null;
+		}
+
+		try {
+			// retrieve service details from data store
+			$account = $this->accountService->find($userId, (int) $serviceId);
+		} catch(\Throwable $th) {
+			return null;
+		}
+
+		// extract values
+		$serviceId = (string) $account->getId();
+		$label = $account->getName();
+		$address = new MailAddress($account->getEmail(), $account->getName());
+		// return mail service object
+		return new MailService($this->container, $userId, $serviceId, $label, $address);
+
+	}
+
+	/**
+	 * retrieve a service for a specific mail address
+	 *
+	 * @since 4.0.0
+	 *
+	 * @param string $userId			system user id
+	 * @param string $address			mail address (e.g. test@example.com)
+	 *
+	 * @return IService					returns service object or null if none found
+	 */
+	public function findServiceByAddress(string $userId, string $address): IService | null {
+
+		try {
+			// retrieve service details from data store
+			$accounts = $this->accountService->findByUserIdAndAddress($userId, $address);
+		} catch(\Throwable $th) {
+			return null;
+		}
+		// evaluate if service details where found
+		if (isset($accounts[0])) {
+			// extract values
+			$serviceId = (string) $accounts[0]->getId();
+			$label = $accounts[0]->getName();
+			$address = new MailAddress($accounts[0]->getEmail(), $accounts[0]->getName());
+			// return mail service object
+			return new MailService($this->container, $userId, $serviceId, $label, $address);
+		}
+
+		return null;
+
+	}
+
+	/**
+	 * construct a new fresh service object
+	 *
+	 * @since 4.0.0
+	 *
+	 * @return IService						fresh service object
+	 */
+	public function initiateService(): IService {
+
+		return new MailService($this->container);
+
+	}
+
+}