[stack] feat(mail): support right-to-left languages in emails

apps/dav/lib/CalDAV/Reminder/NotificationProvider/EmailProvider.php

@@ -96,6 +96,7 @@ public function send(VEvent $vevent,
 			$fromEMail = Util::getDefaultEmailAddress('reminders-noreply');
 
 			$template = $this->mailer->createEMailTemplate('dav.calendarReminder');
+			$template->setLanguage($l10n->getLanguageCode());
 			$template->addHeader();
 			$this->addSubjectAndHeading($template, $l10n, $vevent);
 			$this->addEventDetails($template, $l10n, $calendarDisplayName ?? $this->getCalendarDisplayNameFallback($lang), $vevent);

apps/dav/lib/CalDAV/Schedule/IMipPlugin.php

@@ -221,6 +221,7 @@ public function schedule(Message $iTipMessage) {
 		$fromName = $this->imipService->getFrom($senderName, $this->defaults->getName());
 
 		$template = $this->mailer->createEMailTemplate('dav.calendarInvite.' . $method, $data);
+		$template->setLanguage($this->imipService->getLanguageCode());
 		$template->addHeader();
 		$template->addBodySender($data['invitee_name'], $senderName !== null ? $sender : '');
 

apps/dav/lib/CalDAV/Schedule/IMipService.php

@@ -70,6 +70,13 @@ public function getFrom(?string $senderName, string $default): string {
 		return $this->l10n->t('%1$s via %2$s', [$senderName, $default]);
 	}
 
+	/**
+	 * Language of the attendee the email is written for
+	 */
+	public function getLanguageCode(): string {
+		return $this->l10n->getLanguageCode();
+	}
+
 	public static function readPropertyWithDefault(VEvent $vevent, string $property, string $default) {
 		if (isset($vevent->$property)) {
 			$value = $vevent->$property->getValue();

apps/dav/lib/Listener/CalendarDelegateActionListener.php

@@ -169,6 +169,7 @@ private function sendNotification(
 			'calendar' => $calendarName,
 			'event' => $summary,
 		]);
+		$template->setLanguage($l->getLanguageCode());
 		$template->addHeader();
 		$template->setSubject($subject);
 		$template->addBodySender($actorName, $actor->getEMailAddress() ?? '');

apps/dav/tests/unit/CalDAV/Reminder/NotificationProvider/EmailProviderTest.php

@@ -139,12 +139,16 @@ public function testSendWithAttendeesWhenOwnerIsOrganizer(): void {
 			->willReturnArgument(0);
 		$enL10N->method('l')
 			->willReturnArgument(0);
+		$enL10N->method('getLanguageCode')
+			->willReturn('en');
 
 		$deL10N = $this->createMock(IL10N::class);
 		$deL10N->method('t')
 			->willReturnArgument(0);
 		$deL10N->method('l')
 			->willReturnArgument(0);
+		$deL10N->method('getLanguageCode')
+			->willReturn('de');
 
 		$this->l10nFactory
 			->method('getUserLanguage')
@@ -181,6 +185,12 @@ public function testSendWithAttendeesWhenOwnerIsOrganizer(): void {
 		$message21 = $this->getMessageMock('foo3@example.org', $template2);
 		$message22 = $this->getMessageMock('foo4@example.org', $template2);
 		$message23 = $this->getMessageMock('uid1@example.com', $template2);
+		$template1->expects($this->once())
+			->method('setLanguage')
+			->with('de');
+		$template2->expects($this->once())
+			->method('setLanguage')
+			->with('en');
 
 		$this->mailer->expects(self::exactly(2))
 			->method('createEMailTemplate')

apps/dav/tests/unit/CalDAV/Schedule/IMipPluginTest.php

@@ -230,6 +230,10 @@ public function testParsingSingle(): void {
 			->willReturn($this->user);
 		$this->service->expects(self::once())
 			->method('getFrom');
+		$this->service->method('getLanguageCode')->willReturn('ar');
+		$this->emailTemplate->expects(self::once())
+			->method('setLanguage')
+			->with('ar');
 		$this->emailTemplate->expects(self::once())
 			->method('addBodySender')
 			->with('Mr. Wizard', 'gandalf@wiz.ard');

apps/dav/tests/unit/CalDAV/Schedule/IMipServiceTest.php

@@ -164,6 +164,12 @@ public function testGetFrom(): void {
 		$this->assertEquals($expected, $actual);
 	}
 
+	public function testGetLanguageCode(): void {
+		$this->l10n->method('getLanguageCode')->willReturn('ar');
+
+		$this->assertEquals('ar', $this->service->getLanguageCode());
+	}
+
 	public function testIsSystemUserWhenUserExists(): void {
 		$email = 'user@example.com';
 		$user = $this->createMock(IUser::class);

apps/dav/tests/unit/Listener/CalendarDelegateActionListenerTest.php

@@ -50,6 +50,7 @@ protected function setUp(): void {
 			static fn (string $text, array $parameters = []): string => vsprintf($text, $parameters)
 		);
 		$l10n->method('l')->willReturn('date');
+		$l10n->method('getLanguageCode')->willReturn('de');
 		$l10nFactory = $this->createMock(IFactory::class);
 		$l10nFactory->method('get')->willReturn($l10n);
 
@@ -114,6 +115,9 @@ public function testMailShowsActorAndCalendar(?string $actorEmail, string $expec
 		$owner->method('getEMailAddress')->willReturn('alice@example.com');
 		$this->userManager->method('get')->with('alice')->willReturn($owner);
 
+		$this->template->expects(self::once())
+			->method('setLanguage')
+			->with('de');
 		$this->template->expects(self::once())
 			->method('addBodySender')
 			->with('Bob', $expectedSubline);

apps/encryption/lib/Crypto/EncryptAll.php

@@ -354,6 +354,7 @@ protected function sendPasswordsByMail(): void {
 					'user' => $recipient->getUID(),
 					'password' => $password,
 				]);
+				$template->setLanguage($l->getLanguageCode());
 
 				$template->setSubject($l->t('one-time password for server-side-encryption'));
 				// 'Hey there,<br><br>The administration enabled server-side-encryption. Your files were encrypted using the password <strong>%s</strong>.<br><br>

apps/files_sharing/lib/SharesReminderJob.php

@@ -292,6 +292,7 @@ private function generateEMailTemplate(IL10N $l, array $folder): IEMailTemplate
 		$emailTemplate = $this->mailer->createEMailTemplate('files_sharing.SharesReminder', [
 			'folder' => $folder,
 		]);
+		$emailTemplate->setLanguage($l->getLanguageCode());
 		$emailTemplate->addHeader();
 		$emailTemplate->setSubject(
 			$l->t('Remember to upload the files to %s', [$folder['name']])

apps/files_sharing/tests/SharesReminderJobTest.php

@@ -174,6 +174,10 @@ public function testSharesReminder(
 		$this->mailer->method('createMessage')->willReturn($messageMock);
 		$templateMock = $this->createMock(IEMailTemplate::class);
 		$this->mailer->method('createEMailTemplate')->willReturn($templateMock);
+		$templateMock
+			->expects(($shouldBeReminded ? $this->once() : $this->never()))
+			->method('setLanguage')
+			->with('en');
 		$templateMock
 			->expects(($shouldBeReminded ? $this->once() : $this->never()))
 			->method('addBodyDetails')

apps/settings/lib/Controller/MailSettingsController.php

@@ -133,6 +133,7 @@ public function sendTestMail() {
 				$template = $this->mailer->createEMailTemplate('settings.TestEmail', [
 					'displayname' => $displayName,
 				]);
+				$template->setLanguage($this->l10n->getLanguageCode());
 
 				$template->setSubject($this->l10n->t('Email setting test'));
 				$template->addHeader();

apps/settings/lib/Hooks.php

@@ -107,6 +107,7 @@ public function onChangePassword(PasswordUpdatedEvent $handle): void {
 				'instanceUrl' => $instanceUrl,
 				'event' => $handle,
 			]);
+			$template->setLanguage($l->getLanguageCode());
 
 			$template->setSubject($l->t('Password for %1$s changed on %2$s', [$user->getDisplayName(), $instanceName]));
 			$template->addHeader();
@@ -177,6 +178,7 @@ public function onChangeEmail(UserChangedEvent $handle): void {
 				'oldEMailAddress' => $oldMailAddress,
 				'instanceUrl' => $instanceUrl,
 			]);
+			$template->setLanguage($l->getLanguageCode());
 
 			$template->setSubject($l->t('Email address for %1$s changed on %2$s', [$user->getDisplayName(), $instanceName]));
 			$template->addHeader();

apps/settings/lib/Mailer/NewUserMailHelper.php

@@ -76,6 +76,7 @@ public function generateTemplate(IUser $user, $generatePasswordResetToken = fals
 			'instancename' => $this->themingDefaults->getName(),
 			'resetTokenGenerated' => $generatePasswordResetToken,
 		]);
+		$emailTemplate->setLanguage($l10n->getLanguageCode());
 
 		$emailTemplate->setSubject($l10n->t('Your %s account was created', [$this->themingDefaults->getName()]));
 		$emailTemplate->addHeader();

apps/settings/tests/Controller/MailSettingsControllerTest.php

@@ -157,6 +157,7 @@ public function testSendTestMail(): void {
 			->willReturnCallback(function ($text, $parameters = []) {
 				return vsprintf($text, $parameters);
 			});
+		$this->l->method('getLanguageCode')->willReturn('de');
 		$this->userSession
 			->expects($this->any())
 			->method('getUser')
@@ -176,6 +177,9 @@ public function testSendTestMail(): void {
 			->method('createMessage')
 			->willReturn($this->createMock(Message::class));
 		$emailTemplate = $this->createMock(IEMailTemplate::class);
+		$emailTemplate->expects($this->once())
+			->method('setLanguage')
+			->with('de');
 		$this->mailer
 			->expects($this->once())
 			->method('createEMailTemplate')

apps/settings/tests/HooksTest.php

@@ -48,6 +48,7 @@ protected function setUp(): void {
 
 		$l10n = $this->createMock(IL10N::class);
 		$l10n->method('t')->willReturnCallback(fn (string $text, array $parameters = []): string => vsprintf($text, $parameters));
+		$l10n->method('getLanguageCode')->willReturn('de');
 		$l10nFactory = $this->createMock(IFactory::class);
 		$l10nFactory->method('get')->with('settings')->willReturn($l10n);
 
@@ -80,6 +81,7 @@ protected function setUp(): void {
 	public function testPasswordChangedMail(): void {
 		$this->user->method('getEMailAddress')->willReturn('alice@example.com');
 
+		$this->template->expects($this->once())->method('setLanguage')->with('de');
 		$this->template->expects($this->once())->method('addBodyText')
 			->with('Your password on https://cloud.example.com/ was changed.');
 		$this->template->expects($this->once())->method('addBodyNote')
@@ -93,6 +95,7 @@ public function testEmailChangedMail(): void {
 		$this->user->method('getEMailAddress')->willReturn('new@example.com');
 		$order = [];
 
+		$this->template->expects($this->once())->method('setLanguage')->with('de');
 		$this->template->expects($this->once())->method('addBodyText')
 			->with('Your email address on https://cloud.example.com/ was changed.');
 		$this->template->expects($this->once())->method('addBodyDetails')

apps/sharebymail/lib/ShareByMailProvider.php

@@ -367,6 +367,7 @@ protected function sendEmail(IShare $share, array $emails): void {
 			'shareWith' => $shareWith,
 			'note' => $note
 		]);
+		$emailTemplate->setLanguage($this->l->getLanguageCode());
 
 		$emailTemplate->setSubject($this->l->t('%1$s shared %2$s with you', [$initiatorDisplayName, $filename]));
 		$emailTemplate->addHeader();
@@ -465,6 +466,7 @@ protected function sendPassword(IShare $share, string $password, array $emails):
 			'initiatorEmail' => $initiatorEmailAddress,
 			'shareWith' => $shareWith,
 		]);
+		$emailTemplate->setLanguage($this->l->getLanguageCode());
 
 		$emailTemplate->setSubject($this->l->t('Password to access %1$s shared to you by %2$s', [$filename, $initiatorDisplayName]));
 		$emailTemplate->addHeader();
@@ -543,6 +545,7 @@ protected function sendNote(IShare $share): void {
 		$message = $this->mailer->createMessage();
 
 		$emailTemplate = $this->mailer->createEMailTemplate('shareByMail.sendNote');
+		$emailTemplate->setLanguage($this->l->getLanguageCode());
 
 		$emailTemplate->setSubject($this->l->t('%s added a note to a file shared with you', [$initiatorDisplayName]));
 		$emailTemplate->addHeader();
@@ -609,6 +612,7 @@ protected function sendPasswordToOwner(IShare $share, string $password): bool {
 			'initiatorEmail' => $initiatorEMailAddress,
 			'shareWith' => $shareWith,
 		]);
+		$emailTemplate->setLanguage($this->l->getLanguageCode());
 
 		$emailTemplate->setSubject($this->l->t('Password to access %1$s shared by you with %2$s', [$filename, $shareWith]));
 		$emailTemplate->addHeader();

apps/sharebymail/tests/ShareByMailProviderTest.php

@@ -81,6 +81,7 @@ protected function setUp(): void {
 			->willReturnCallback(function ($text, $parameters = []) {
 				return vsprintf($text, $parameters);
 			});
+		$this->l->method('getLanguageCode')->willReturn('de');
 		$this->config = $this->createMock(IConfig::class);
 		$this->logger = $this->createMock(LoggerInterface::class);
 		$this->rootFolder = $this->createMock('OCP\Files\IRootFolder');
@@ -437,7 +438,9 @@ public function testCreateSendPasswordByMailWithEnforcedPasswordProtectionWithPe
 			->willReturnCallback(function () use (&$calls) {
 				$expected = array_shift($calls);
 				$this->assertEquals($expected, func_get_args());
-				return $this->createMock(IEMailTemplate::class);
+				$template = $this->createMock(IEMailTemplate::class);
+				$template->expects($this->once())->method('setLanguage')->with('de');
+				return $template;
 			});
 
 		// Main email notification is sent as well as the password
@@ -616,7 +619,9 @@ public function testCreateSendPasswordByTalkWithEnforcedPasswordProtectionWithPe
 			->willReturnCallback(function () use (&$calls) {
 				$expected = array_shift($calls);
 				$this->assertEquals($expected, func_get_args());
-				return $this->createMock(IEMailTemplate::class);
+				$template = $this->createMock(IEMailTemplate::class);
+				$template->expects($this->once())->method('setLanguage')->with('de');
+				return $template;
 			});
 
 		// Main email notification is sent as well as the password to owner
@@ -1334,6 +1339,10 @@ public function testSendMailNotificationWithSameUserAndUserEmail(): void {
 			->expects($this->once())
 			->method('createEMailTemplate')
 			->willReturn($template);
+		$template
+			->expects($this->once())
+			->method('setLanguage')
+			->with('de');
 		$template
 			->expects($this->once())
 			->method('addHeader');
@@ -1987,6 +1996,7 @@ public function testSendNote(bool $replyToInitiator, string $senderSubline): voi
 		$this->mailer->method('createEMailTemplate')->willReturn($template);
 		$this->mailer->expects($this->once())->method('send')->with($message);
 
+		$template->expects($this->once())->method('setLanguage')->with('de');
 		$template->expects($this->once())->method('addBodySender')->with('Sharer', $senderSubline);
 		$template->expects($this->once())->method('addHeading')->with('Sharer shared file.txt with you', 'Sharer shared file.txt with you');
 		$template->expects($this->once())->method('addBodyNote')->with('A note & more', 'Note');

core/BackgroundJobs/CheckCodeIntegrityJob.php

@@ -194,6 +194,7 @@ private function sendMail(IUser $admin, array $summary): void {
 		$l = $this->l10nFactory->get('core', $this->l10nFactory->getUserLanguage($admin));
 
 		$template = $this->mailer->createEMailTemplate('core.CodeIntegrityChanged', $summary);
+		$template->setLanguage($l->getLanguageCode());
 		$template->setSubject($l->t('The code integrity check result has changed'));
 		$template->addHeader();
 		$template->addHeading($l->t('The code integrity check result has changed'));

core/Controller/LostController.php

@@ -255,6 +255,7 @@ protected function sendEmail(string $input): void {
 		$emailTemplate = $this->mailer->createEMailTemplate('core.ResetPassword', [
 			'link' => $link,
 		]);
+		$emailTemplate->setLanguage($this->l10n->getLanguageCode());
 
 		$emailTemplate->setSubject($this->l10n->t('%s password reset', [$this->defaults->getName()]));
 		$emailTemplate->addHeader();

lib/private/Accounts/AccountManager.php

@@ -314,6 +314,7 @@ protected function sendEmailVerificationEmail(IUser $user, string $email): bool
 		if (!$this->l10n) {
 			$this->l10n = $this->l10nFactory->get('core');
 		}
+		$emailTemplate->setLanguage($this->l10n->getLanguageCode());
 
 		$emailTemplate->setSubject($this->l10n->t('%s email verification', [$this->defaults->getName()]));
 		$emailTemplate->addHeader();

lib/private/Authentication/Listeners/RemoteWipeEmailListener.php

@@ -93,6 +93,7 @@ public function handle(Event $event): void {
 	private function getWipingStartedMessage(RemoteWipeStarted $event, IUser $user): IMessage {
 		$message = $this->mailer->createMessage();
 		$emailTemplate = $this->mailer->createEMailTemplate('auth.RemoteWipeStarted');
+		$emailTemplate->setLanguage($this->l10n->getLanguageCode());
 		$plainHeading = $this->l10n->t('Wiping of device %s has started', [$event->getToken()->getName()]);
 		$htmlHeading = $this->l10n->t('Wiping of device »%s« has started', [$event->getToken()->getName()]);
 		$emailTemplate->setSubject(
@@ -123,6 +124,7 @@ private function getWipingStartedMessage(RemoteWipeStarted $event, IUser $user):
 	private function getWipingFinishedMessage(RemoteWipeFinished $event, IUser $user): IMessage {
 		$message = $this->mailer->createMessage();
 		$emailTemplate = $this->mailer->createEMailTemplate('auth.RemoteWipeFinished');
+		$emailTemplate->setLanguage($this->l10n->getLanguageCode());
 		$plainHeading = $this->l10n->t('Wiping of device %s has finished', [$event->getToken()->getName()]);
 		$htmlHeading = $this->l10n->t('Wiping of device »%s« has finished', [$event->getToken()->getName()]);
 		$emailTemplate->setSubject(

lib/private/Mail/EMailTemplate.php

@@ -36,6 +36,8 @@ class EMailTemplate implements IEMailTemplate {
 	protected bool $bodyListOpened = false;
 	/** indicated if the footer is added */
 	protected bool $footerAdded = false;
+	/** language of the recipient, set by setLanguage */
+	protected ?string $language = null;
 	/** name of the person the email is sent on behalf of, set by addBodySender */
 	protected ?string $senderName = null;
 	/** @var array<array{name: string, content: string, mimeType: string}> images to embed inline, referenced via cid: */
@@ -308,6 +310,13 @@ public function addHeader(): void {
 		$this->htmlBody .= vsprintf($this->header, [$this->themingDefaults->getDefaultColorPrimary(), $logoSrc, $this->themingDefaults->getName(), $logoSizeDimensions]);
 	}
 
+	#[\Override]
+	public function setLanguage(string $language): void {
+		if ($language !== '') {
+			$this->language = $language;
+		}
+	}
+
 	/**
 	 * Images that must be embedded inline in the message, referenced via `cid:<name>` in the HTML body
 	 *
@@ -746,6 +755,7 @@ protected function ensureBodyIsClosed(): void {
 	 */
 	#[\Override]
 	public function addFooter(string $text = '', ?string $lang = null): void {
+		$lang ??= $this->language;
 		$plainText = null;
 		if ($text === '') {
 			$l10n = $this->l10nFactory->get('lib', $lang);
@@ -797,7 +807,28 @@ public function renderHtml(): string {
 			$this->ensureBodyIsClosed();
 			$this->htmlBody .= $this->tail;
 		}
-		return $this->htmlBody;
+		if ($this->language === null) {
+			return $this->htmlBody;
+		}
+
+		$direction = $this->l10nFactory->getLanguageDirection($this->language);
+		$lang = htmlspecialchars(str_replace('_', '-', $this->language));
+		$html = str_replace('lang="en" xml:lang="en"', 'lang="' . $lang . '" xml:lang="' . $lang . '" dir="' . $direction . '"', $this->htmlBody);
+		return $direction === 'rtl' ? $this->mirrorStyles($html) : $html;
+	}
+
+	/**
+	 * Swap left and right in the template's own styles: the style attributes
+	 * and the style element. Text content is never touched.
+	 */
+	protected function mirrorStyles(string $html): string {
+		$mirror = static function (array $match): string {
+			// 4-value margin and padding shorthands are top, right, bottom, left
+			$css = preg_replace('/\\b(margin|padding):([^\\s;"!]+) ([^\\s;"!]+) ([^\\s;"!]+) ([^\\s;"!]+)/', '$1:$2 $5 $4 $3', $match[2]) ?? $match[2];
+			return $match[1] . strtr($css, ['left' => 'right', 'right' => 'left']) . $match[3];
+		};
+		$html = preg_replace_callback('/(style=")([^"]*)(")/', $mirror, $html) ?? $html;
+		return preg_replace_callback('/(<style[^>]*>)(.*?)(<\\/style>)/s', $mirror, $html) ?? $html;
 	}
 
 	/**