Merge pull request #51029 from nextcloud/fix/deprecate-oc-template-and-cleanup

fix: Deprecate OC_Template, add proper template manager instead

36 files changed, 813 insertions, 659 deletions

diff --git a/apps/dav/lib/Files/BrowserErrorPagePlugin.php b/apps/dav/lib/Files/BrowserErrorPagePlugin.php
index 1491e1a89b1..de86c4995e2 100644
--- a/apps/dav/lib/Files/BrowserErrorPagePlugin.php
+++ b/apps/dav/lib/Files/BrowserErrorPagePlugin.php
@@ -8,9 +8,10 @@
 namespace OCA\DAV\Files;
 
 use OC\AppFramework\Http\Request;
-use OC_Template;
 use OCP\AppFramework\Http\ContentSecurityPolicy;
+use OCP\AppFramework\Http\TemplateResponse;
 use OCP\IRequest;
+use OCP\Template\ITemplateManager;
 use Sabre\DAV\Exception;
 use Sabre\DAV\Server;
 use Sabre\DAV\ServerPlugin;
@@ -84,7 +85,7 @@ class BrowserErrorPagePlugin extends ServerPlugin {
 			$templateName = (string)$httpCode;
 		}
 
-		$content = new OC_Template('core', $templateName, 'guest');
+		$content = \OCP\Server::get(ITemplateManager::class)->getTemplate('core', $templateName, TemplateResponse::RENDER_AS_GUEST);
 		$content->assign('title', $this->server->httpResponse->getStatusText());
 		$content->assign('remoteAddr', $request->getRemoteAddress());
 		$content->assign('requestID', $request->getId());
diff --git a/apps/twofactor_backupcodes/lib/Provider/BackupCodesProvider.php b/apps/twofactor_backupcodes/lib/Provider/BackupCodesProvider.php
index 8bb044448c1..12959f57e9b 100644
--- a/apps/twofactor_backupcodes/lib/Provider/BackupCodesProvider.php
+++ b/apps/twofactor_backupcodes/lib/Provider/BackupCodesProvider.php
@@ -17,7 +17,8 @@ use OCP\Authentication\TwoFactorAuth\IProvidesPersonalSettings;
 use OCP\IInitialStateService;
 use OCP\IL10N;
 use OCP\IUser;
-use OCP\Template;
+use OCP\Template\ITemplate;
+use OCP\Template\ITemplateManager;
 
 class BackupCodesProvider implements IDeactivatableByAdmin, IProvidesPersonalSettings {
 
@@ -36,6 +37,7 @@ class BackupCodesProvider implements IDeactivatableByAdmin, IProvidesPersonalSet
 		private IL10N $l10n,
 		AppManager $appManager,
 		private IInitialStateService $initialStateService,
+		private ITemplateManager $templateManager,
 	) {
 		$this->appManager = $appManager;
 	}
@@ -71,10 +73,10 @@ class BackupCodesProvider implements IDeactivatableByAdmin, IProvidesPersonalSet
 	 * Get the template for rending the 2FA provider view
 	 *
 	 * @param IUser $user
-	 * @return Template
+	 * @return ITemplate
 	 */
-	public function getTemplate(IUser $user): Template {
-		return new Template('twofactor_backupcodes', 'challenge');
+	public function getTemplate(IUser $user): ITemplate {
+		return $this->templateManager->getTemplate('twofactor_backupcodes', 'challenge');
 	}
 
 	/**
diff --git a/apps/twofactor_backupcodes/lib/Settings/Personal.php b/apps/twofactor_backupcodes/lib/Settings/Personal.php
index 894597dd053..e03c3d303db 100644
--- a/apps/twofactor_backupcodes/lib/Settings/Personal.php
+++ b/apps/twofactor_backupcodes/lib/Settings/Personal.php
@@ -6,13 +6,16 @@ declare(strict_types=1);
  * SPDX-FileCopyrightText: 2016 Nextcloud GmbH and Nextcloud contributors
  * SPDX-License-Identifier: AGPL-3.0-or-later
  */
+
 namespace OCA\TwoFactorBackupCodes\Settings;
 
 use OCP\Authentication\TwoFactorAuth\IPersonalProviderSettings;
-use OCP\Template;
+use OCP\Server;
+use OCP\Template\ITemplate;
+use OCP\Template\ITemplateManager;
 
 class Personal implements IPersonalProviderSettings {
-	public function getBody(): Template {
-		return new Template('twofactor_backupcodes', 'personal');
+	public function getBody(): ITemplate {
+		return Server::get(ITemplateManager::class)->getTemplate('twofactor_backupcodes', 'personal');
 	}
 }
diff --git a/apps/twofactor_backupcodes/tests/Unit/Provider/BackupCodesProviderTest.php b/apps/twofactor_backupcodes/tests/Unit/Provider/BackupCodesProviderTest.php
index 24e986710c4..cef3e07a36e 100644
--- a/apps/twofactor_backupcodes/tests/Unit/Provider/BackupCodesProviderTest.php
+++ b/apps/twofactor_backupcodes/tests/Unit/Provider/BackupCodesProviderTest.php
@@ -14,28 +14,21 @@ use OCA\TwoFactorBackupCodes\Service\BackupCodeStorage;
 use OCP\IInitialStateService;
 use OCP\IL10N;
 use OCP\IUser;
-use OCP\Template;
+use OCP\Server;
+use OCP\Template\ITemplateManager;
+use PHPUnit\Framework\MockObject\MockObject;
 use Test\TestCase;
 
 class BackupCodesProviderTest extends TestCase {
+	private string $appName;
 
-	/** @var string */
-	private $appName;
+	private BackupCodeStorage&MockObject $storage;
+	private IL10N&MockObject $l10n;
+	private AppManager&MockObject $appManager;
+	private IInitialStateService&MockObject $initialState;
 
-	/** @var BackupCodeStorage|\PHPUnit\Framework\MockObject\MockObject */
-	private $storage;
-
-	/** @var IL10N|\PHPUnit\Framework\MockObject\MockObject */
-	private $l10n;
-
-	/** @var AppManager|\PHPUnit\Framework\MockObject\MockObject */
-	private $appManager;
-
-	/** @var IInitialStateService|\PHPUnit\Framework\MockObject\MockObject */
-	private $initialState;
-
-	/** @var BackupCodesProvider */
-	private $provider;
+	private ITemplateManager $templateManager;
+	private BackupCodesProvider $provider;
 
 	protected function setUp(): void {
 		parent::setUp();
@@ -45,8 +38,16 @@ class BackupCodesProviderTest extends TestCase {
 		$this->l10n = $this->createMock(IL10N::class);
 		$this->appManager = $this->createMock(AppManager::class);
 		$this->initialState = $this->createMock(IInitialStateService::class);
-
-		$this->provider = new BackupCodesProvider($this->appName, $this->storage, $this->l10n, $this->appManager, $this->initialState);
+		$this->templateManager = Server::get(ITemplateManager::class);
+
+		$this->provider = new BackupCodesProvider(
+			$this->appName,
+			$this->storage,
+			$this->l10n,
+			$this->appManager,
+			$this->initialState,
+			$this->templateManager,
+		);
 	}
 
 	public function testGetId(): void {
@@ -71,7 +72,7 @@ class BackupCodesProviderTest extends TestCase {
 
 	public function testGetTempalte(): void {
 		$user = $this->getMockBuilder(IUser::class)->getMock();
-		$expected = new Template('twofactor_backupcodes', 'challenge');
+		$expected = $this->templateManager->getTemplate('twofactor_backupcodes', 'challenge');
 
 		$this->assertEquals($expected, $this->provider->getTemplate($user));
 	}
diff --git a/apps/user_ldap/lib/Settings/Admin.php b/apps/user_ldap/lib/Settings/Admin.php
index bf75d3ce378..014210ca8f0 100644
--- a/apps/user_ldap/lib/Settings/Admin.php
+++ b/apps/user_ldap/lib/Settings/Admin.php
@@ -13,14 +13,12 @@ use OCP\IDBConnection;
 use OCP\IL10N;
 use OCP\Server;
 use OCP\Settings\IDelegatedSettings;
-use OCP\Template;
+use OCP\Template\ITemplateManager;
 
 class Admin implements IDelegatedSettings {
-	/**
-	 * @param IL10N $l
-	 */
 	public function __construct(
 		private IL10N $l,
+		private ITemplateManager $templateManager,
 	) {
 	}
 
@@ -40,11 +38,12 @@ class Admin implements IDelegatedSettings {
 
 		$hosts = $helper->getServerConfigurationHosts();
 
-		$wControls = new Template('user_ldap', 'part.wizardcontrols');
+		$wControls = $this->templateManager->getTemplate('user_ldap', 'part.wizardcontrols');
 		$wControls = $wControls->fetchPage();
-		$sControls = new Template('user_ldap', 'part.settingcontrols');
+		$sControls = $this->templateManager->getTemplate('user_ldap', 'part.settingcontrols');
 		$sControls = $sControls->fetchPage();
 
+		$parameters = [];
 		$parameters['serverConfigurationPrefixes'] = $prefixes;
 		$parameters['serverConfigurationHosts'] = $hosts;
 		$parameters['settingControls'] = $sControls;
diff --git a/apps/user_ldap/tests/Settings/AdminTest.php b/apps/user_ldap/tests/Settings/AdminTest.php
index 099cc09c068..05b9697e4c8 100644
--- a/apps/user_ldap/tests/Settings/AdminTest.php
+++ b/apps/user_ldap/tests/Settings/AdminTest.php
@@ -9,7 +9,9 @@ use OCA\User_LDAP\Configuration;
 use OCA\User_LDAP\Settings\Admin;
 use OCP\AppFramework\Http\TemplateResponse;
 use OCP\IL10N;
-use OCP\Template;
+use OCP\Server;
+use OCP\Template\ITemplateManager;
+use PHPUnit\Framework\MockObject\MockObject;
 use Test\TestCase;
 
 /**
@@ -17,17 +19,19 @@ use Test\TestCase;
  * @package OCA\User_LDAP\Tests\Settings
  */
 class AdminTest extends TestCase {
-	/** @var Admin */
-	private $admin;
-	/** @var IL10N */
-	private $l10n;
+	private IL10N&MockObject $l10n;
+
+	private ITemplateManager $templateManager;
+	private Admin $admin;
 
 	protected function setUp(): void {
 		parent::setUp();
 		$this->l10n = $this->getMockBuilder(IL10N::class)->getMock();
+		$this->templateManager = Server::get(ITemplateManager::class);
 
 		$this->admin = new Admin(
-			$this->l10n
+			$this->l10n,
+			$this->templateManager,
 		);
 	}
 
@@ -38,11 +42,12 @@ class AdminTest extends TestCase {
 		$prefixes = ['s01'];
 		$hosts = ['s01' => ''];
 
-		$wControls = new Template('user_ldap', 'part.wizardcontrols');
+		$wControls = $this->templateManager->getTemplate('user_ldap', 'part.wizardcontrols');
 		$wControls = $wControls->fetchPage();
-		$sControls = new Template('user_ldap', 'part.settingcontrols');
+		$sControls = $this->templateManager->getTemplate('user_ldap', 'part.settingcontrols');
 		$sControls = $sControls->fetchPage();
 
+		$parameters = [];
 		$parameters['serverConfigurationPrefixes'] = $prefixes;
 		$parameters['serverConfigurationHosts'] = $hosts;
 		$parameters['settingControls'] = $sControls;
diff --git a/apps/workflowengine/lib/Listener/LoadAdditionalSettingsScriptsListener.php b/apps/workflowengine/lib/Listener/LoadAdditionalSettingsScriptsListener.php
index 3b5f3f0ae11..e5a03fdcb2e 100644
--- a/apps/workflowengine/lib/Listener/LoadAdditionalSettingsScriptsListener.php
+++ b/apps/workflowengine/lib/Listener/LoadAdditionalSettingsScriptsListener.php
@@ -6,25 +6,18 @@ declare(strict_types=1);
  * SPDX-FileCopyrightText: 2020 Nextcloud GmbH and Nextcloud contributors
  * SPDX-License-Identifier: AGPL-3.0-or-later
  */
+
 namespace OCA\WorkflowEngine\Listener;
 
 use OCA\WorkflowEngine\AppInfo\Application;
 use OCP\EventDispatcher\Event;
 use OCP\EventDispatcher\IEventListener;
-use OCP\Template;
 use OCP\Util;
 use OCP\WorkflowEngine\Events\LoadSettingsScriptsEvent;
-use function class_exists;
-use function function_exists;
 
 /** @template-implements IEventListener<LoadSettingsScriptsEvent> */
 class LoadAdditionalSettingsScriptsListener implements IEventListener {
 	public function handle(Event $event): void {
-		if (!function_exists('style')) {
-			// This is hacky, but we need to load the template class
-			class_exists(Template::class, true);
-		}
-
 		Util::addScript('core', 'files_fileinfo');
 		Util::addScript('core', 'files_client');
 		Util::addScript('core', 'systemtags');
diff --git a/build/psalm-baseline-ocp.xml b/build/psalm-baseline-ocp.xml
index 9f69654ff3d..ce406cfde75 100644
--- a/build/psalm-baseline-ocp.xml
+++ b/build/psalm-baseline-ocp.xml
@@ -1,10 +1,5 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <files psalm-version="5.26.1@d747f6500b38ac4f7dfc5edbcae6e4b637d7add0">
-  <file src="lib/private/legacy/OC_Template.php">
-    <UndefinedClass>
-      <code><![CDATA[OC]]></code>
-    </UndefinedClass>
-  </file>
   <file src="lib/public/AppFramework/ApiController.php">
     <NoInterfaceProperties>
       <code><![CDATA[$this->request->server]]></code>
diff --git a/build/psalm-baseline.xml b/build/psalm-baseline.xml
index cecea953d00..3e3b373ec34 100644
--- a/build/psalm-baseline.xml
+++ b/build/psalm-baseline.xml
@@ -2601,11 +2601,6 @@
       <code><![CDATA[getQuota]]></code>
     </UndefinedInterfaceMethod>
   </file>
-  <file src="lib/private/legacy/OC_Template.php">
-    <InvalidReturnType>
-      <code><![CDATA[bool|string]]></code>
-    </InvalidReturnType>
-  </file>
   <file src="lib/private/legacy/OC_User.php">
     <UndefinedClass>
       <code><![CDATA[\Test\Util\User\Dummy]]></code>
diff --git a/core/Controller/SetupController.php b/core/Controller/SetupController.php
index bd3b8265c34..4b5902fdd3c 100644
--- a/core/Controller/SetupController.php
+++ b/core/Controller/SetupController.php
@@ -8,6 +8,7 @@
 namespace OC\Core\Controller;
 
 use OC\Setup;
+use OCP\Template\ITemplateManager;
 use OCP\Util;
 use Psr\Log\LoggerInterface;
 
@@ -17,6 +18,7 @@ class SetupController {
 	public function __construct(
 		protected Setup $setupHelper,
 		protected LoggerInterface $logger,
+		protected ITemplateManager $templateManager,
 	) {
 		$this->autoConfigFile = \OC::$configDir . 'autoconfig.php';
 	}
@@ -57,10 +59,10 @@ class SetupController {
 	}
 
 	private function displaySetupForbidden(): void {
-		\OC_Template::printGuestPage('', 'installation_forbidden');
+		$this->templateManager->printGuestPage('', 'installation_forbidden');
 	}
 
-	public function display($post): void {
+	public function display(array $post): void {
 		$defaults = [
 			'adminlogin' => '',
 			'adminpass' => '',
@@ -80,7 +82,7 @@ class SetupController {
 		Util::addScript('core', 'main');
 		Util::addTranslations('core');
 
-		\OC_Template::printGuestPage('', 'installation', $parameters);
+		$this->templateManager->printGuestPage('', 'installation', $parameters);
 	}
 
 	private function finishSetup(): void {
@@ -90,7 +92,7 @@ class SetupController {
 		\OC::$server->getIntegrityCodeChecker()->runInstanceVerification();
 
 		if ($this->setupHelper->shouldRemoveCanInstallFile()) {
-			\OC_Template::printGuestPage('', 'installation_incomplete');
+			$this->templateManager->printGuestPage('', 'installation_incomplete');
 		}
 
 		header('Location: ' . \OC::$server->getURLGenerator()->getAbsoluteURL('index.php/core/apps/recommended'));
diff --git a/index.php b/index.php
index f3ed07c3572..b368462371d 100644
--- a/index.php
+++ b/index.php
@@ -16,6 +16,7 @@ use OCP\HintException;
 use OCP\IRequest;
 use OCP\Security\Bruteforce\MaxDelayReached;
 use OCP\Server;
+use OCP\Template\ITemplateManager;
 use Psr\Log\LoggerInterface;
 
 try {
@@ -29,10 +30,10 @@ try {
 	]);
 
 	//show the user a detailed error page
-	OC_Template::printExceptionErrorPage($ex, 503);
+	Server::get(ITemplateManager::class)->printExceptionErrorPage($ex, 503);
 } catch (HintException $ex) {
 	try {
-		OC_Template::printErrorPage($ex->getMessage(), $ex->getHint(), 503);
+		Server::get(ITemplateManager::class)->printErrorPage($ex->getMessage(), $ex->getHint(), 503);
 	} catch (Exception $ex2) {
 		try {
 			Server::get(LoggerInterface::class)->error($ex->getMessage(), [
@@ -48,7 +49,7 @@ try {
 		}
 
 		//show the user a detailed error page
-		OC_Template::printExceptionErrorPage($ex, 500);
+		Server::get(ITemplateManager::class)->printExceptionErrorPage($ex, 500);
 	}
 } catch (LoginException $ex) {
 	$request = Server::get(IRequest::class);
@@ -63,7 +64,7 @@ try {
 		echo json_encode(['message' => $ex->getMessage()]);
 		exit();
 	}
-	OC_Template::printErrorPage($ex->getMessage(), $ex->getMessage(), 401);
+	Server::get(ITemplateManager::class)->printErrorPage($ex->getMessage(), $ex->getMessage(), 401);
 } catch (MaxDelayReached $ex) {
 	$request = Server::get(IRequest::class);
 	/**
@@ -78,7 +79,7 @@ try {
 		exit();
 	}
 	http_response_code(429);
-	OC_Template::printGuestPage('core', '429');
+	Server::get(ITemplateManager::class)->printGuestPage('core', '429');
 } catch (Exception $ex) {
 	Server::get(LoggerInterface::class)->error($ex->getMessage(), [
 		'app' => 'index',
@@ -86,7 +87,7 @@ try {
 	]);
 
 	//show the user a detailed error page
-	OC_Template::printExceptionErrorPage($ex, 500);
+	Server::get(ITemplateManager::class)->printExceptionErrorPage($ex, 500);
 } catch (Error $ex) {
 	try {
 		Server::get(LoggerInterface::class)->error($ex->getMessage(), [
@@ -103,5 +104,5 @@ try {
 
 		throw $ex;
 	}
-	OC_Template::printExceptionErrorPage($ex, 500);
+	Server::get(ITemplateManager::class)->printExceptionErrorPage($ex, 500);
 }
diff --git a/lib/base.php b/lib/base.php
index 7a7b9c64dd9..bda6b6e01a1 100644
--- a/lib/base.php
+++ b/lib/base.php
@@ -21,6 +21,7 @@ use OCP\IUserSession;
 use OCP\Security\Bruteforce\IThrottler;
 use OCP\Server;
 use OCP\Share;
+use OCP\Template\ITemplateManager;
 use OCP\User\Events\UserChangedEvent;
 use OCP\User\Events\UserDeletedEvent;
 use OCP\Util;
@@ -208,7 +209,7 @@ class OC {
 				echo $l->t('See %s', [ $urlGenerator->linkToDocs('admin-config') ]) . "\n";
 				exit;
 			} else {
-				OC_Template::printErrorPage(
+				Server::get(ITemplateManager::class)->printErrorPage(
 					$l->t('Cannot write into "config" directory!'),
 					$l->t('This can usually be fixed by giving the web server write access to the config directory.') . ' '
 					. $l->t('But, if you prefer to keep config.php file read only, set the option "config_is_read_only" to true in it.') . ' '
@@ -244,7 +245,7 @@ class OC {
 			header('Retry-After: 120');
 
 			// render error page
-			$template = new OC_Template('', 'update.user', 'guest');
+			$template = Server::get(ITemplateManager::class)->getTemplate('', 'update.user', 'guest');
 			\OCP\Util::addScript('core', 'maintenance');
 			\OCP\Util::addStyle('core', 'guest');
 			$template->printPage();
@@ -300,7 +301,7 @@ class OC {
 			$serverVersion = \OCP\Server::get(\OCP\ServerVersion::class);
 
 			// render error page
-			$template = new OC_Template('', 'update.use-cli', 'guest');
+			$template = Server::get(ITemplateManager::class)->getTemplate('', 'update.use-cli', 'guest');
 			$template->assign('productName', 'nextcloud'); // for now
 			$template->assign('version', $serverVersion->getVersionString());
 			$template->assign('tooBig', $tooBig);
@@ -327,7 +328,7 @@ class OC {
 		/** @var \OC\App\AppManager $appManager */
 		$appManager = Server::get(\OCP\App\IAppManager::class);
 
-		$tmpl = new OC_Template('', 'update.admin', 'guest');
+		$tmpl = Server::get(ITemplateManager::class)->getTemplate('', 'update.admin', 'guest');
 		$tmpl->assign('version', \OCP\Server::get(\OCP\ServerVersion::class)->getVersionString());
 		$tmpl->assign('isAppsOnlyUpgrade', $isAppsOnlyUpgrade);
 
@@ -420,7 +421,7 @@ class OC {
 		} catch (Exception $e) {
 			Server::get(LoggerInterface::class)->error($e->getMessage(), ['app' => 'base','exception' => $e]);
 			//show the user a detailed error page
-			OC_Template::printExceptionErrorPage($e, 500);
+			Server::get(ITemplateManager::class)->printExceptionErrorPage($e, 500);
 			die();
 		}
 
@@ -662,7 +663,7 @@ class OC {
 			if ($config->getSystemValueBool('debug', false)) {
 				set_error_handler([$errorHandler, 'onAll'], E_ALL);
 				if (\OC::$CLI) {
-					$exceptionHandler = ['OC_Template', 'printExceptionErrorPage'];
+					$exceptionHandler = [Server::get(ITemplateManager::class), 'printExceptionErrorPage'];
 				}
 			} else {
 				set_error_handler([$errorHandler, 'onError']);
@@ -705,7 +706,7 @@ class OC {
 					http_response_code(503);
 					OC_Util::addStyle('guest');
 					try {
-						OC_Template::printGuestPage('', 'error', ['errors' => $errors]);
+						Server::get(ITemplateManager::class)->printGuestPage('', 'error', ['errors' => $errors]);
 						exit;
 					} catch (\Exception $e) {
 						// In case any error happens when showing the error page, we simply fall back to posting the text.
@@ -784,7 +785,7 @@ class OC {
 		// Check whether the sample configuration has been copied
 		if ($systemConfig->getValue('copied_sample_config', false)) {
 			$l = Server::get(\OCP\L10N\IFactory::class)->get('lib');
-			OC_Template::printErrorPage(
+			Server::get(ITemplateManager::class)->printErrorPage(
 				$l->t('Sample configuration detected'),
 				$l->t('It has been detected that the sample configuration has been copied. This can break your installation and is unsupported. Please read the documentation before performing changes on config.php'),
 				503
@@ -826,7 +827,7 @@ class OC {
 					]
 				);
 
-				$tmpl = new OCP\Template('core', 'untrustedDomain', 'guest');
+				$tmpl = Server::get(ITemplateManager::class)->getTemplate('core', 'untrustedDomain', 'guest');
 				$tmpl->assign('docUrl', Server::get(IURLGenerator::class)->linkToDocs('admin-trusted-domains'));
 				$tmpl->printPage();
 
@@ -1097,7 +1098,7 @@ class OC {
 				logger('core')->emergency($e->getMessage(), ['exception' => $e]);
 			}
 			$l = Server::get(\OCP\L10N\IFactory::class)->get('lib');
-			OC_Template::printErrorPage(
+			Server::get(ITemplateManager::class)->printErrorPage(
 				'404',
 				$l->t('The page could not be found on the server.'),
 				404
diff --git a/lib/composer/composer/autoload_classmap.php b/lib/composer/composer/autoload_classmap.php
index d900941fd1a..c353ff32c3a 100644
--- a/lib/composer/composer/autoload_classmap.php
+++ b/lib/composer/composer/autoload_classmap.php
@@ -850,6 +850,9 @@ return array(
     'OCP\\Teams\\Team' => $baseDir . '/lib/public/Teams/Team.php',
     'OCP\\Teams\\TeamResource' => $baseDir . '/lib/public/Teams/TeamResource.php',
     'OCP\\Template' => $baseDir . '/lib/public/Template.php',
+    'OCP\\Template\\ITemplate' => $baseDir . '/lib/public/Template/ITemplate.php',
+    'OCP\\Template\\ITemplateManager' => $baseDir . '/lib/public/Template/ITemplateManager.php',
+    'OCP\\Template\\TemplateNotFoundException' => $baseDir . '/lib/public/Template/TemplateNotFoundException.php',
     'OCP\\TextProcessing\\Events\\AbstractTextProcessingEvent' => $baseDir . '/lib/public/TextProcessing/Events/AbstractTextProcessingEvent.php',
     'OCP\\TextProcessing\\Events\\TaskFailedEvent' => $baseDir . '/lib/public/TextProcessing/Events/TaskFailedEvent.php',
     'OCP\\TextProcessing\\Events\\TaskSuccessfulEvent' => $baseDir . '/lib/public/TextProcessing/Events/TaskSuccessfulEvent.php',
@@ -2048,7 +2051,9 @@ return array(
     'OC\\Template\\JSResourceLocator' => $baseDir . '/lib/private/Template/JSResourceLocator.php',
     'OC\\Template\\ResourceLocator' => $baseDir . '/lib/private/Template/ResourceLocator.php',
     'OC\\Template\\ResourceNotFoundException' => $baseDir . '/lib/private/Template/ResourceNotFoundException.php',
+    'OC\\Template\\Template' => $baseDir . '/lib/private/Template/Template.php',
     'OC\\Template\\TemplateFileLocator' => $baseDir . '/lib/private/Template/TemplateFileLocator.php',
+    'OC\\Template\\TemplateManager' => $baseDir . '/lib/private/Template/TemplateManager.php',
     'OC\\TextProcessing\\Db\\Task' => $baseDir . '/lib/private/TextProcessing/Db/Task.php',
     'OC\\TextProcessing\\Db\\TaskMapper' => $baseDir . '/lib/private/TextProcessing/Db/TaskMapper.php',
     'OC\\TextProcessing\\Manager' => $baseDir . '/lib/private/TextProcessing/Manager.php',
diff --git a/lib/composer/composer/autoload_static.php b/lib/composer/composer/autoload_static.php
index 36886be53f3..dd4b0943d2f 100644
--- a/lib/composer/composer/autoload_static.php
+++ b/lib/composer/composer/autoload_static.php
@@ -899,6 +899,9 @@ class ComposerStaticInit749170dad3f5e7f9ca158f5a9f04f6a2
         'OCP\\Teams\\Team' => __DIR__ . '/../../..' . '/lib/public/Teams/Team.php',
         'OCP\\Teams\\TeamResource' => __DIR__ . '/../../..' . '/lib/public/Teams/TeamResource.php',
         'OCP\\Template' => __DIR__ . '/../../..' . '/lib/public/Template.php',
+        'OCP\\Template\\ITemplate' => __DIR__ . '/../../..' . '/lib/public/Template/ITemplate.php',
+        'OCP\\Template\\ITemplateManager' => __DIR__ . '/../../..' . '/lib/public/Template/ITemplateManager.php',
+        'OCP\\Template\\TemplateNotFoundException' => __DIR__ . '/../../..' . '/lib/public/Template/TemplateNotFoundException.php',
         'OCP\\TextProcessing\\Events\\AbstractTextProcessingEvent' => __DIR__ . '/../../..' . '/lib/public/TextProcessing/Events/AbstractTextProcessingEvent.php',
         'OCP\\TextProcessing\\Events\\TaskFailedEvent' => __DIR__ . '/../../..' . '/lib/public/TextProcessing/Events/TaskFailedEvent.php',
         'OCP\\TextProcessing\\Events\\TaskSuccessfulEvent' => __DIR__ . '/../../..' . '/lib/public/TextProcessing/Events/TaskSuccessfulEvent.php',
@@ -2097,7 +2100,9 @@ class ComposerStaticInit749170dad3f5e7f9ca158f5a9f04f6a2
         'OC\\Template\\JSResourceLocator' => __DIR__ . '/../../..' . '/lib/private/Template/JSResourceLocator.php',
         'OC\\Template\\ResourceLocator' => __DIR__ . '/../../..' . '/lib/private/Template/ResourceLocator.php',
         'OC\\Template\\ResourceNotFoundException' => __DIR__ . '/../../..' . '/lib/private/Template/ResourceNotFoundException.php',
+        'OC\\Template\\Template' => __DIR__ . '/../../..' . '/lib/private/Template/Template.php',
         'OC\\Template\\TemplateFileLocator' => __DIR__ . '/../../..' . '/lib/private/Template/TemplateFileLocator.php',
+        'OC\\Template\\TemplateManager' => __DIR__ . '/../../..' . '/lib/private/Template/TemplateManager.php',
         'OC\\TextProcessing\\Db\\Task' => __DIR__ . '/../../..' . '/lib/private/TextProcessing/Db/Task.php',
         'OC\\TextProcessing\\Db\\TaskMapper' => __DIR__ . '/../../..' . '/lib/private/TextProcessing/Db/TaskMapper.php',
         'OC\\TextProcessing\\Manager' => __DIR__ . '/../../..' . '/lib/private/TextProcessing/Manager.php',
diff --git a/lib/private/Server.php b/lib/private/Server.php
index 8c5ec8ed252..523fc7b9914 100644
--- a/lib/private/Server.php
+++ b/lib/private/Server.php
@@ -286,6 +286,7 @@ class Server extends ServerContainer implements IServerContainer {
 
 		$this->registerAlias(\OCP\DirectEditing\IManager::class, \OC\DirectEditing\Manager::class);
 		$this->registerAlias(ITemplateManager::class, TemplateManager::class);
+		$this->registerAlias(\OCP\Template\ITemplateManager::class, \OC\Template\TemplateManager::class);
 
 		$this->registerAlias(IActionFactory::class, ActionFactory::class);
 
diff --git a/lib/private/Template/Base.php b/lib/private/Template/Base.php
index 602c8e6257e..0dd7d92d6be 100644
--- a/lib/private/Template/Base.php
+++ b/lib/private/Template/Base.php
@@ -8,11 +8,10 @@
 namespace OC\Template;
 
 use OCP\Defaults;
-use Throwable;
 
 class Base {
 	private $template; // The template
-	private $vars; // Vars
+	private array $vars = [];
 
 	/** @var \OCP\IL10N */
 	private $l10n;
@@ -59,11 +58,9 @@ class Base {
 	}
 
 	/**
-	 * @param string $serverRoot
-	 * @param string $theme
 	 * @return string[]
 	 */
-	protected function getCoreTemplateDirs($theme, $serverRoot) {
+	protected function getCoreTemplateDirs(string $theme, string $serverRoot): array {
 		return [
 			$serverRoot . '/themes/' . $theme . '/core/templates/',
 			$serverRoot . '/core/templates/',
@@ -72,30 +69,24 @@ class Base {
 
 	/**
 	 * Assign variables
-	 * @param string $key key
-	 * @param float|array|bool|integer|string|Throwable $value value
-	 * @return bool
 	 *
 	 * This function assigns a variable. It can be accessed via $_[$key] in
 	 * the template.
 	 *
 	 * If the key existed before, it will be overwritten
 	 */
-	public function assign($key, $value) {
+	public function assign(string $key, mixed $value): void {
 		$this->vars[$key] = $value;
-		return true;
 	}
 
 	/**
 	 * Appends a variable
-	 * @param string $key key
-	 * @param mixed $value value
 	 *
 	 * This function assigns a variable in an array context. If the key already
 	 * exists, the value will be appended. It can be accessed via
 	 * $_[$key][$position] in the template.
 	 */
-	public function append($key, $value) {
+	public function append(string $key, mixed $value): void {
 		if (array_key_exists($key, $this->vars)) {
 			$this->vars[$key][] = $value;
 		} else {
@@ -105,42 +96,29 @@ class Base {
 
 	/**
 	 * Prints the proceeded template
-	 * @return bool
 	 *
 	 * This function proceeds the template and prints its output.
 	 */
-	public function printPage() {
+	public function printPage(): void {
 		$data = $this->fetchPage();
-		if ($data === false) {
-			return false;
-		} else {
-			print $data;
-			return true;
-		}
+		print $data;
 	}
 
 	/**
 	 * Process the template
 	 *
-	 * @param array|null $additionalParams
-	 * @return string This function processes the template.
-	 *
 	 * This function processes the template.
 	 */
-	public function fetchPage($additionalParams = null) {
+	public function fetchPage(?array $additionalParams = null): string {
 		return $this->load($this->template, $additionalParams);
 	}
 
 	/**
 	 * doing the actual work
 	 *
-	 * @param string $file
-	 * @param array|null $additionalParams
-	 * @return string content
-	 *
 	 * Includes the template file, fetches its output
 	 */
-	protected function load($file, $additionalParams = null) {
+	protected function load(string $file, ?array $additionalParams = null): string {
 		// Register the variables
 		$_ = $this->vars;
 		$l = $this->l10n;
diff --git a/lib/private/Template/Template.php b/lib/private/Template/Template.php
new file mode 100644
index 00000000000..b69d68b944f
--- /dev/null
+++ b/lib/private/Template/Template.php
@@ -0,0 +1,161 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * SPDX-FileCopyrightText: 2016-2024 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-FileCopyrightText: 2016 ownCloud, Inc.
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+namespace OC\Template;
+
+use OC\Security\CSP\ContentSecurityPolicyNonceManager;
+use OC\TemplateLayout;
+use OCP\App\AppPathNotFoundException;
+use OCP\App\IAppManager;
+use OCP\AppFramework\Http\TemplateResponse;
+use OCP\Defaults;
+use OCP\Server;
+use OCP\Template\ITemplate;
+use OCP\Template\TemplateNotFoundException;
+use OCP\Util;
+
+require_once __DIR__ . '/../legacy/template/functions.php';
+
+class Template extends Base implements ITemplate {
+	private string $path;
+	private array $headers = [];
+
+	/**
+	 * @param string $app app providing the template
+	 * @param string $name of the template file (without suffix)
+	 * @param TemplateResponse::RENDER_AS_* $renderAs If $renderAs is set, will try to
+	 *                                                produce a full page in the according layout.
+	 * @throws TemplateNotFoundException
+	 */
+	public function __construct(
+		protected string $app,
+		string $name,
+		private string $renderAs = TemplateResponse::RENDER_AS_BLANK,
+		bool $registerCall = true,
+	) {
+		$theme = \OC_Util::getTheme();
+
+		$requestToken = ($registerCall ? Util::callRegister() : '');
+		$cspNonce = Server::get(ContentSecurityPolicyNonceManager::class)->getNonce();
+
+		// fix translation when app is something like core/lostpassword
+		$parts = explode('/', $app);
+		$l10n = Util::getL10N($parts[0]);
+
+		[$path, $template] = $this->findTemplate($theme, $app, $name);
+
+		$this->path = $path;
+
+		parent::__construct(
+			$template,
+			$requestToken,
+			$l10n,
+			Server::get(Defaults::class),
+			$cspNonce,
+		);
+	}
+
+
+	/**
+	 * find the template with the given name
+	 *
+	 * Will select the template file for the selected theme.
+	 * Checking all the possible locations.
+	 *
+	 * @param string $name of the template file (without suffix)
+	 * @return array{string,string} Directory path and filename
+	 * @throws TemplateNotFoundException
+	 */
+	protected function findTemplate(string $theme, string $app, string $name): array {
+		// Check if it is a app template or not.
+		if ($app !== '') {
+			try {
+				$appDir = Server::get(IAppManager::class)->getAppPath($app);
+			} catch (AppPathNotFoundException) {
+				$appDir = false;
+			}
+			$dirs = $this->getAppTemplateDirs($theme, $app, \OC::$SERVERROOT, $appDir);
+		} else {
+			$dirs = $this->getCoreTemplateDirs($theme, \OC::$SERVERROOT);
+		}
+		$locator = new TemplateFileLocator($dirs);
+		return $locator->find($name);
+	}
+
+	/**
+	 * Add a custom element to the header
+	 * @param string $tag tag name of the element
+	 * @param array $attributes array of attributes for the element
+	 * @param string $text the text content for the element. If $text is null then the
+	 *                     element will be written as empty element. So use "" to get a closing tag.
+	 */
+	public function addHeader(string $tag, array $attributes, ?string $text = null): void {
+		$this->headers[] = [
+			'tag' => $tag,
+			'attributes' => $attributes,
+			'text' => $text
+		];
+	}
+
+	/**
+	 * Process the template
+	 *
+	 * This function process the template. If $this->renderAs is set, it
+	 * will produce a full page.
+	 */
+	public function fetchPage(?array $additionalParams = null): string {
+		$data = parent::fetchPage($additionalParams);
+
+		if ($this->renderAs) {
+			$page = Server::get(TemplateLayout::class)->getPageTemplate($this->renderAs, $this->app);
+
+			if (is_array($additionalParams)) {
+				foreach ($additionalParams as $key => $value) {
+					$page->assign($key, $value);
+				}
+			}
+
+			// Add custom headers
+			$headers = '';
+			foreach (\OC_Util::$headers as $header) {
+				$headers .= '<' . Util::sanitizeHTML($header['tag']);
+				if (strcasecmp($header['tag'], 'script') === 0 && in_array('src', array_map('strtolower', array_keys($header['attributes'])))) {
+					$headers .= ' defer';
+				}
+				foreach ($header['attributes'] as $name => $value) {
+					$headers .= ' ' . Util::sanitizeHTML($name) . '="' . Util::sanitizeHTML($value) . '"';
+				}
+				if ($header['text'] !== null) {
+					$headers .= '>' . Util::sanitizeHTML($header['text']) . '</' . Util::sanitizeHTML($header['tag']) . '>';
+				} else {
+					$headers .= '/>';
+				}
+			}
+
+			$page->assign('headers', $headers);
+			$page->assign('content', $data);
+			return $page->fetchPage($additionalParams);
+		}
+
+		return $data;
+	}
+
+	/**
+	 * Include template
+	 *
+	 * @return string returns content of included template
+	 *
+	 * Includes another template. use <?php echo $this->inc('template'); ?> to
+	 * do this.
+	 */
+	public function inc(string $file, ?array $additionalParams = null): string {
+		return $this->load($this->path . $file . '.php', $additionalParams);
+	}
+}
diff --git a/lib/private/Template/TemplateFileLocator.php b/lib/private/Template/TemplateFileLocator.php
index 38583d158a3..11a568b5b21 100644
--- a/lib/private/Template/TemplateFileLocator.php
+++ b/lib/private/Template/TemplateFileLocator.php
@@ -1,29 +1,31 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * SPDX-FileCopyrightText: 2016-2024 Nextcloud GmbH and Nextcloud contributors
  * SPDX-FileCopyrightText: 2016 ownCloud, Inc.
  * SPDX-License-Identifier: AGPL-3.0-only
  */
+
 namespace OC\Template;
 
-class TemplateFileLocator {
-	protected $dirs;
-	private $path;
+use OCP\Template\TemplateNotFoundException;
 
+class TemplateFileLocator {
 	/**
 	 * @param string[] $dirs
 	 */
-	public function __construct($dirs) {
-		$this->dirs = $dirs;
+	public function __construct(
+		private array $dirs,
+	) {
 	}
 
 	/**
-	 * @param string $template
-	 * @return string
-	 * @throws \Exception
+	 * @return array{string,string} Directory path and filename
+	 * @throws TemplateNotFoundException
 	 */
-	public function find($template) {
+	public function find(string $template): array {
 		if ($template === '') {
 			throw new \InvalidArgumentException('Empty template name');
 		}
@@ -31,14 +33,9 @@ class TemplateFileLocator {
 		foreach ($this->dirs as $dir) {
 			$file = $dir . $template . '.php';
 			if (is_file($file)) {
-				$this->path = $dir;
-				return $file;
+				return [$dir,$file];
 			}
 		}
-		throw new \Exception('template file not found: template:' . $template);
-	}
-
-	public function getPath() {
-		return $this->path;
+		throw new TemplateNotFoundException('template file not found: template:' . $template);
 	}
 }
diff --git a/lib/private/Template/TemplateManager.php b/lib/private/Template/TemplateManager.php
new file mode 100644
index 00000000000..34da4deac72
--- /dev/null
+++ b/lib/private/Template/TemplateManager.php
@@ -0,0 +1,169 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * SPDX-FileCopyrightText: 2025 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+namespace OC\Template;
+
+use OCP\App\IAppManager;
+use OCP\AppFramework\Http\Events\BeforeTemplateRenderedEvent;
+use OCP\AppFramework\Http\TemplateResponse;
+use OCP\EventDispatcher\IEventDispatcher;
+use OCP\IRequest;
+use OCP\Server;
+use OCP\Template\ITemplate;
+use OCP\Template\ITemplateManager;
+use OCP\Template\TemplateNotFoundException;
+use Psr\Log\LoggerInterface;
+
+class TemplateManager implements ITemplateManager {
+	public function __construct(
+		private IAppManager $appManager,
+		private IEventDispatcher $eventDispatcher,
+	) {
+	}
+
+	/**
+	 * @param TemplateResponse::RENDER_AS_* $renderAs
+	 * @throws TemplateNotFoundException if the template cannot be found
+	 */
+	public function getTemplate(string $app, string $name, string $renderAs = TemplateResponse::RENDER_AS_BLANK, bool $registerCall = true): ITemplate {
+		return new Template($app, $name, $renderAs, $registerCall);
+	}
+
+	/**
+	 * Shortcut to print a simple page for guests
+	 * @param string $application The application we render the template for
+	 * @param string $name Name of the template
+	 * @param array $parameters Parameters for the template
+	 */
+	public function printGuestPage(string $application, string $name, array $parameters = []): void {
+		$content = $this->getTemplate($application, $name, $name === 'error' ? $name : 'guest');
+		foreach ($parameters as $key => $value) {
+			$content->assign($key, $value);
+		}
+		$content->printPage();
+	}
+
+	/**
+	 * Print a fatal error page and terminates the script
+	 * @param string $error_msg The error message to show
+	 * @param string $hint An optional hint message - needs to be properly escape
+	 */
+	public function printErrorPage(string $error_msg, string $hint = '', int $statusCode = 500): never {
+		if ($this->appManager->isEnabledForUser('theming') && !$this->appManager->isAppLoaded('theming')) {
+			$this->appManager->loadApp('theming');
+		}
+
+		if ($error_msg === $hint) {
+			// If the hint is the same as the message there is no need to display it twice.
+			$hint = '';
+		}
+		$errors = [['error' => $error_msg, 'hint' => $hint]];
+
+		http_response_code($statusCode);
+		try {
+			// Try rendering themed html error page
+			$response = new TemplateResponse(
+				'',
+				'error',
+				['errors' => $errors],
+				TemplateResponse::RENDER_AS_ERROR,
+				$statusCode,
+			);
+			$event = new BeforeTemplateRenderedEvent(false, $response);
+			$this->eventDispatcher->dispatchTyped($event);
+			print($response->render());
+		} catch (\Throwable $e1) {
+			$logger = \OCP\Server::get(LoggerInterface::class);
+			$logger->error('Rendering themed error page failed. Falling back to un-themed error page.', [
+				'app' => 'core',
+				'exception' => $e1,
+			]);
+
+			try {
+				// Try rendering unthemed html error page
+				$content = $this->getTemplate('', 'error', 'error', false);
+				$content->assign('errors', $errors);
+				$content->printPage();
+			} catch (\Exception $e2) {
+				// If nothing else works, fall back to plain text error page
+				$logger->error("$error_msg $hint", ['app' => 'core']);
+				$logger->error('Rendering un-themed error page failed. Falling back to plain text error page.', [
+					'app' => 'core',
+					'exception' => $e2,
+				]);
+
+				header('Content-Type: text/plain; charset=utf-8');
+				print("$error_msg $hint");
+			}
+		}
+		die();
+	}
+
+	/**
+	 * print error page using Exception details
+	 */
+	public function printExceptionErrorPage(\Throwable $exception, int $statusCode = 503): never {
+		$debug = false;
+		http_response_code($statusCode);
+		try {
+			$debug = (bool)Server::get(\OC\SystemConfig::class)->getValue('debug', false);
+			$serverLogsDocumentation = Server::get(\OC\SystemConfig::class)->getValue('documentation_url.server_logs', '');
+			$request = Server::get(IRequest::class);
+			$content = $this->getTemplate('', 'exception', 'error', false);
+			$content->assign('errorClass', get_class($exception));
+			$content->assign('errorMsg', $exception->getMessage());
+			$content->assign('errorCode', $exception->getCode());
+			$content->assign('file', $exception->getFile());
+			$content->assign('line', $exception->getLine());
+			$content->assign('exception', $exception);
+			$content->assign('debugMode', $debug);
+			$content->assign('serverLogsDocumentation', $serverLogsDocumentation);
+			$content->assign('remoteAddr', $request->getRemoteAddress());
+			$content->assign('requestID', $request->getId());
+			$content->printPage();
+		} catch (\Exception $e) {
+			try {
+				$logger = Server::get(LoggerInterface::class);
+				$logger->error($exception->getMessage(), ['app' => 'core', 'exception' => $exception]);
+				$logger->error($e->getMessage(), ['app' => 'core', 'exception' => $e]);
+			} catch (\Throwable $e) {
+				// no way to log it properly - but to avoid a white page of death we send some output
+				$this->printPlainErrorPage($e, $debug);
+
+				// and then throw it again to log it at least to the web server error log
+				throw $e;
+			}
+
+			$this->printPlainErrorPage($e, $debug);
+		}
+		die();
+	}
+
+	/**
+	 * @psalm-taint-escape has_quotes
+	 * @psalm-taint-escape html
+	 */
+	private function fakeEscapeForPlainText(string $str): string {
+		return $str;
+	}
+
+	private function printPlainErrorPage(\Throwable $exception, bool $debug = false): void {
+		header('Content-Type: text/plain; charset=utf-8');
+		print("Internal Server Error\n\n");
+		print("The server encountered an internal error and was unable to complete your request.\n");
+		print("Please contact the server administrator if this error reappears multiple times, please include the technical details below in your report.\n");
+		print("More details can be found in the server log.\n");
+
+		if ($debug) {
+			print("\n");
+			print($exception->getMessage() . ' ' . $exception->getFile() . ' at ' . $exception->getLine() . "\n");
+			print($this->fakeEscapeForPlainText($exception->getTraceAsString()));
+		}
+	}
+}
diff --git a/lib/private/TemplateLayout.php b/lib/private/TemplateLayout.php
index e52ef702ad3..9c1d7ca1d2c 100644
--- a/lib/private/TemplateLayout.php
+++ b/lib/private/TemplateLayout.php
@@ -1,5 +1,7 @@
 <?php
 
+declare(strict_types=1);
+
 /**
  * SPDX-FileCopyrightText: 2016-2024 Nextcloud GmbH and Nextcloud contributors
  * SPDX-FileCopyrightText: 2016 ownCloud, Inc.
@@ -25,36 +27,31 @@ use OCP\IRequest;
 use OCP\IURLGenerator;
 use OCP\IUserSession;
 use OCP\L10N\IFactory;
+use OCP\Server;
 use OCP\ServerVersion;
 use OCP\Support\Subscription\IRegistry;
+use OCP\Template\ITemplate;
+use OCP\Template\ITemplateManager;
 use OCP\Util;
 
-class TemplateLayout extends \OC_Template {
-	private static $versionHash = '';
+class TemplateLayout {
+	private static string $versionHash = '';
 	/** @var string[] */
-	private static $cacheBusterCache = [];
-
-	/** @var CSSResourceLocator|null */
-	public static $cssLocator = null;
-
-	/** @var JSResourceLocator|null */
-	public static $jsLocator = null;
-
-	private IConfig $config;
-	private IAppManager $appManager;
-	private InitialStateService $initialState;
-	private INavigationManager $navigationManager;
-
-	/**
-	 * @param string $renderAs
-	 * @param string $appId application id
-	 */
-	public function __construct($renderAs, $appId = '') {
-		$this->config = \OCP\Server::get(IConfig::class);
-		$this->appManager = \OCP\Server::get(IAppManager::class);
-		$this->initialState = \OCP\Server::get(InitialStateService::class);
-		$this->navigationManager = \OCP\Server::get(INavigationManager::class);
+	private static array $cacheBusterCache = [];
+
+	public static ?CSSResourceLocator $cssLocator = null;
+	public static ?JSResourceLocator $jsLocator = null;
+
+	public function __construct(
+		private IConfig $config,
+		private IAppManager $appManager,
+		private InitialStateService $initialState,
+		private INavigationManager $navigationManager,
+		private ITemplateManager $templateManager,
+	) {
+	}
 
+	public function getPageTemplate(string $renderAs, string $appId): ITemplate {
 		// Add fallback theming variables if not rendered as user
 		if ($renderAs !== TemplateResponse::RENDER_AS_USER) {
 			// TODO cache generated default theme if enabled for fallback if server is erroring ?
@@ -62,146 +59,148 @@ class TemplateLayout extends \OC_Template {
 		}
 
 		// Decide which page we show
-		if ($renderAs === TemplateResponse::RENDER_AS_USER) {
-			parent::__construct('core', 'layout.user');
-			if (in_array(\OC_App::getCurrentApp(), ['settings','admin', 'help']) !== false) {
-				$this->assign('bodyid', 'body-settings');
-			} else {
-				$this->assign('bodyid', 'body-user');
-			}
-
-			$this->initialState->provideInitialState('core', 'active-app', $this->navigationManager->getActiveEntry());
-			$this->initialState->provideInitialState('core', 'apps', array_values($this->navigationManager->getAll()));
-
-			if ($this->config->getSystemValueBool('unified_search.enabled', false) || !$this->config->getSystemValueBool('enable_non-accessible_features', true)) {
-				$this->initialState->provideInitialState('unified-search', 'limit-default', (int)$this->config->getAppValue('core', 'unified-search.limit-default', (string)SearchQuery::LIMIT_DEFAULT));
-				$this->initialState->provideInitialState('unified-search', 'min-search-length', (int)$this->config->getAppValue('core', 'unified-search.min-search-length', (string)1));
-				$this->initialState->provideInitialState('unified-search', 'live-search', $this->config->getAppValue('core', 'unified-search.live-search', 'yes') === 'yes');
-				Util::addScript('core', 'legacy-unified-search', 'core');
-			} else {
-				Util::addScript('core', 'unified-search', 'core');
-			}
-			// Set body data-theme
-			$this->assign('enabledThemes', []);
-			if ($this->appManager->isEnabledForUser('theming') && class_exists('\OCA\Theming\Service\ThemesService')) {
-				/** @var \OCA\Theming\Service\ThemesService */
-				$themesService = \OC::$server->get(\OCA\Theming\Service\ThemesService::class);
-				$this->assign('enabledThemes', $themesService->getEnabledThemes());
-			}
-
-			// Set logo link target
-			$logoUrl = $this->config->getSystemValueString('logo_url', '');
-			$this->assign('logoUrl', $logoUrl);
-
-			// Set default entry name
-			$defaultEntryId = $this->navigationManager->getDefaultEntryIdForUser();
-			$defaultEntry = $this->navigationManager->get($defaultEntryId);
-			$this->assign('defaultAppName', $defaultEntry['name']);
+		switch ($renderAs) {
+			case TemplateResponse::RENDER_AS_USER:
+				$page = $this->templateManager->getTemplate('core', 'layout.user');
+				if (in_array(\OC_App::getCurrentApp(), ['settings','admin', 'help']) !== false) {
+					$page->assign('bodyid', 'body-settings');
+				} else {
+					$page->assign('bodyid', 'body-user');
+				}
 
-			// Add navigation entry
-			$this->assign('application', '');
-			$this->assign('appid', $appId);
+				$this->initialState->provideInitialState('core', 'active-app', $this->navigationManager->getActiveEntry());
+				$this->initialState->provideInitialState('core', 'apps', array_values($this->navigationManager->getAll()));
 
-			$navigation = $this->navigationManager->getAll();
-			$this->assign('navigation', $navigation);
-			$settingsNavigation = $this->navigationManager->getAll('settings');
-			$this->initialState->provideInitialState('core', 'settingsNavEntries', $settingsNavigation);
+				if ($this->config->getSystemValueBool('unified_search.enabled', false) || !$this->config->getSystemValueBool('enable_non-accessible_features', true)) {
+					$this->initialState->provideInitialState('unified-search', 'limit-default', (int)$this->config->getAppValue('core', 'unified-search.limit-default', (string)SearchQuery::LIMIT_DEFAULT));
+					$this->initialState->provideInitialState('unified-search', 'min-search-length', (int)$this->config->getAppValue('core', 'unified-search.min-search-length', (string)1));
+					$this->initialState->provideInitialState('unified-search', 'live-search', $this->config->getAppValue('core', 'unified-search.live-search', 'yes') === 'yes');
+					Util::addScript('core', 'legacy-unified-search', 'core');
+				} else {
+					Util::addScript('core', 'unified-search', 'core');
+				}
+				// Set body data-theme
+				$page->assign('enabledThemes', []);
+				if ($this->appManager->isEnabledForUser('theming') && class_exists('\OCA\Theming\Service\ThemesService')) {
+					$themesService = Server::get(\OCA\Theming\Service\ThemesService::class);
+					$page->assign('enabledThemes', $themesService->getEnabledThemes());
+				}
 
-			foreach ($navigation as $entry) {
-				if ($entry['active']) {
-					$this->assign('application', $entry['name']);
-					break;
+				// Set logo link target
+				$logoUrl = $this->config->getSystemValueString('logo_url', '');
+				$page->assign('logoUrl', $logoUrl);
+
+				// Set default entry name
+				$defaultEntryId = $this->navigationManager->getDefaultEntryIdForUser();
+				$defaultEntry = $this->navigationManager->get($defaultEntryId);
+				$page->assign('defaultAppName', $defaultEntry['name'] ?? '');
+
+				// Add navigation entry
+				$page->assign('application', '');
+				$page->assign('appid', $appId);
+
+				$navigation = $this->navigationManager->getAll();
+				$page->assign('navigation', $navigation);
+				$settingsNavigation = $this->navigationManager->getAll('settings');
+				$this->initialState->provideInitialState('core', 'settingsNavEntries', $settingsNavigation);
+
+				foreach ($navigation as $entry) {
+					if ($entry['active']) {
+						$page->assign('application', $entry['name']);
+						break;
+					}
 				}
-			}
 
-			foreach ($settingsNavigation as $entry) {
-				if ($entry['active']) {
-					$this->assign('application', $entry['name']);
-					break;
+				foreach ($settingsNavigation as $entry) {
+					if ($entry['active']) {
+						$page->assign('application', $entry['name']);
+						break;
+					}
 				}
-			}
 
-			$userDisplayName = false;
-			$user = \OC::$server->get(IUserSession::class)->getUser();
-			if ($user) {
-				$userDisplayName = $user->getDisplayName();
-			}
-			$this->assign('user_displayname', $userDisplayName);
-			$this->assign('user_uid', \OC_User::getUser());
+				$user = Server::get(IUserSession::class)->getUser();
 
-			if ($user === null) {
-				$this->assign('userAvatarSet', false);
-				$this->assign('userStatus', false);
-			} else {
-				$this->assign('userAvatarSet', true);
-				$this->assign('userAvatarVersion', $this->config->getUserValue(\OC_User::getUser(), 'avatar', 'version', 0));
-			}
-		} elseif ($renderAs === TemplateResponse::RENDER_AS_ERROR) {
-			parent::__construct('core', 'layout.guest', '', false);
-			$this->assign('bodyid', 'body-login');
-			$this->assign('user_displayname', '');
-			$this->assign('user_uid', '');
-		} elseif ($renderAs === TemplateResponse::RENDER_AS_GUEST) {
-			parent::__construct('core', 'layout.guest');
-			\OC_Util::addStyle('guest');
-			$this->assign('bodyid', 'body-login');
-
-			$userDisplayName = false;
-			$user = \OC::$server->get(IUserSession::class)->getUser();
-			if ($user) {
-				$userDisplayName = $user->getDisplayName();
-			}
-			$this->assign('user_displayname', $userDisplayName);
-			$this->assign('user_uid', \OC_User::getUser());
-		} elseif ($renderAs === TemplateResponse::RENDER_AS_PUBLIC) {
-			parent::__construct('core', 'layout.public');
-			$this->assign('appid', $appId);
-			$this->assign('bodyid', 'body-public');
-
-			// Set body data-theme
-			$this->assign('enabledThemes', []);
-			if ($this->appManager->isEnabledForUser('theming') && class_exists('\OCA\Theming\Service\ThemesService')) {
-				/** @var \OCA\Theming\Service\ThemesService $themesService */
-				$themesService = \OC::$server->get(\OCA\Theming\Service\ThemesService::class);
-				$this->assign('enabledThemes', $themesService->getEnabledThemes());
-			}
+				if ($user === null) {
+					$page->assign('user_uid', false);
+					$page->assign('user_displayname', false);
+					$page->assign('userAvatarSet', false);
+					$page->assign('userStatus', false);
+				} else {
+					$page->assign('user_uid', $user->getUID());
+					$page->assign('user_displayname', $user->getDisplayName());
+					$page->assign('userAvatarSet', true);
+					$page->assign('userAvatarVersion', $this->config->getUserValue($user->getUID(), 'avatar', 'version', 0));
+				}
+				break;
+			case TemplateResponse::RENDER_AS_ERROR:
+				$page = $this->templateManager->getTemplate('core', 'layout.guest', '', false);
+				$page->assign('bodyid', 'body-login');
+				$page->assign('user_displayname', '');
+				$page->assign('user_uid', '');
+				break;
+			case TemplateResponse::RENDER_AS_GUEST:
+				$page = $this->templateManager->getTemplate('core', 'layout.guest');
+				Util::addStyle('guest');
+				$page->assign('bodyid', 'body-login');
+
+				$userDisplayName = false;
+				$user = Server::get(IUserSession::class)->getUser();
+				if ($user) {
+					$userDisplayName = $user->getDisplayName();
+				}
+				$page->assign('user_displayname', $userDisplayName);
+				$page->assign('user_uid', \OC_User::getUser());
+				break;
+			case TemplateResponse::RENDER_AS_PUBLIC:
+				$page = $this->templateManager->getTemplate('core', 'layout.public');
+				$page->assign('appid', $appId);
+				$page->assign('bodyid', 'body-public');
+
+				// Set body data-theme
+				$page->assign('enabledThemes', []);
+				if ($this->appManager->isEnabledForUser('theming') && class_exists('\OCA\Theming\Service\ThemesService')) {
+					$themesService = Server::get(\OCA\Theming\Service\ThemesService::class);
+					$page->assign('enabledThemes', $themesService->getEnabledThemes());
+				}
 
-			// Set logo link target
-			$logoUrl = $this->config->getSystemValueString('logo_url', '');
-			$this->assign('logoUrl', $logoUrl);
+				// Set logo link target
+				$logoUrl = $this->config->getSystemValueString('logo_url', '');
+				$page->assign('logoUrl', $logoUrl);
 
-			/** @var IRegistry $subscription */
-			$subscription = \OCP\Server::get(IRegistry::class);
-			$showSimpleSignup = $this->config->getSystemValueBool('simpleSignUpLink.shown', true);
-			if ($showSimpleSignup && $subscription->delegateHasValidSubscription()) {
-				$showSimpleSignup = false;
-			}
+				$subscription = Server::get(IRegistry::class);
+				$showSimpleSignup = $this->config->getSystemValueBool('simpleSignUpLink.shown', true);
+				if ($showSimpleSignup && $subscription->delegateHasValidSubscription()) {
+					$showSimpleSignup = false;
+				}
 
-			$defaultSignUpLink = 'https://nextcloud.com/signup/';
-			$signUpLink = $this->config->getSystemValueString('registration_link', $defaultSignUpLink);
-			if ($signUpLink !== $defaultSignUpLink) {
-				$showSimpleSignup = true;
-			}
+				$defaultSignUpLink = 'https://nextcloud.com/signup/';
+				$signUpLink = $this->config->getSystemValueString('registration_link', $defaultSignUpLink);
+				if ($signUpLink !== $defaultSignUpLink) {
+					$showSimpleSignup = true;
+				}
 
-			if ($this->appManager->isEnabledForUser('registration')) {
-				$urlGenerator = \OCP\Server::get(IURLGenerator::class);
-				$signUpLink = $urlGenerator->getAbsoluteURL('/index.php/apps/registration/');
-			}
+				if ($this->appManager->isEnabledForUser('registration')) {
+					$urlGenerator = Server::get(IURLGenerator::class);
+					$signUpLink = $urlGenerator->getAbsoluteURL('/index.php/apps/registration/');
+				}
 
-			$this->assign('showSimpleSignUpLink', $showSimpleSignup);
-			$this->assign('signUpLink', $signUpLink);
-		} else {
-			parent::__construct('core', 'layout.base');
+				$page->assign('showSimpleSignUpLink', $showSimpleSignup);
+				$page->assign('signUpLink', $signUpLink);
+				break;
+			default:
+				$page = $this->templateManager->getTemplate('core', 'layout.base');
+				break;
 		}
 		// Send the language, locale, and direction to our layouts
-		$lang = \OC::$server->get(IFactory::class)->findLanguage();
-		$locale = \OC::$server->get(IFactory::class)->findLocale($lang);
-		$direction = \OC::$server->getL10NFactory()->getLanguageDirection($lang);
+		$l10nFactory = Server::get(IFactory::class);
+		$lang = $l10nFactory->findLanguage();
+		$locale = $l10nFactory->findLocale($lang);
+		$direction = $l10nFactory->getLanguageDirection($lang);
 
 		$lang = str_replace('_', '-', $lang);
-		$this->assign('language', $lang);
-		$this->assign('locale', $locale);
-		$this->assign('direction', $direction);
+		$page->assign('language', $lang);
+		$page->assign('locale', $locale);
+		$page->assign('direction', $direction);
 
 		if ($this->config->getSystemValueBool('installed', false)) {
 			if (empty(self::$versionHash)) {
@@ -216,7 +215,7 @@ class TemplateLayout extends \OC_Template {
 		// Add the js files
 		// TODO: remove deprecated OC_Util injection
 		$jsFiles = self::findJavascriptFiles(array_merge(\OC_Util::$scripts, Util::getScripts()));
-		$this->assign('jsfiles', []);
+		$page->assign('jsfiles', []);
 		if ($this->config->getSystemValueBool('installed', false) && $renderAs != TemplateResponse::RENDER_AS_ERROR) {
 			// this is on purpose outside of the if statement below so that the initial state is prefilled (done in the getConfig() call)
 			// see https://github.com/nextcloud/server/pull/22636 for details
@@ -238,26 +237,28 @@ class TemplateLayout extends \OC_Template {
 			);
 			$config = $jsConfigHelper->getConfig();
 			if (\OC::$server->getContentSecurityPolicyNonceManager()->browserSupportsCspV3()) {
-				$this->assign('inline_ocjs', $config);
+				$page->assign('inline_ocjs', $config);
 			} else {
-				$this->append('jsfiles', \OC::$server->getURLGenerator()->linkToRoute('core.OCJS.getConfig', ['v' => self::$versionHash]));
+				$page->append('jsfiles', \OC::$server->getURLGenerator()->linkToRoute('core.OCJS.getConfig', ['v' => self::$versionHash]));
 			}
 		}
 		foreach ($jsFiles as $info) {
 			$web = $info[1];
 			$file = $info[2];
-			$this->append('jsfiles', $web . '/' . $file . $this->getVersionHashSuffix());
+			$page->append('jsfiles', $web . '/' . $file . $this->getVersionHashSuffix());
 		}
 
+		$request = \OCP\Server::get(IRequest::class);
+
 		try {
-			$pathInfo = \OC::$server->getRequest()->getPathInfo();
+			$pathInfo = $request->getPathInfo();
 		} catch (\Exception $e) {
 			$pathInfo = '';
 		}
 
 		// Do not initialise scss appdata until we have a fully installed instance
 		// Do not load scss for update, errors, installation or login page
-		if (\OC::$server->getSystemConfig()->getValue('installed', false)
+		if ($this->config->getSystemValueBool('installed', false)
 			&& !\OCP\Util::needUpgrade()
 			&& $pathInfo !== ''
 			&& !preg_match('/^\/login/', $pathInfo)
@@ -267,41 +268,42 @@ class TemplateLayout extends \OC_Template {
 		} else {
 			// If we ignore the scss compiler,
 			// we need to load the guest css fallback
-			\OC_Util::addStyle('guest');
-			$cssFiles = self::findStylesheetFiles(\OC_Util::$styles, false);
+			Util::addStyle('guest');
+			$cssFiles = self::findStylesheetFiles(\OC_Util::$styles);
 		}
 
-		$this->assign('cssfiles', []);
-		$this->assign('printcssfiles', []);
+		$page->assign('cssfiles', []);
+		$page->assign('printcssfiles', []);
 		$this->initialState->provideInitialState('core', 'versionHash', self::$versionHash);
 		foreach ($cssFiles as $info) {
 			$web = $info[1];
 			$file = $info[2];
 
 			if (str_ends_with($file, 'print.css')) {
-				$this->append('printcssfiles', $web . '/' . $file . $this->getVersionHashSuffix());
+				$page->append('printcssfiles', $web . '/' . $file . $this->getVersionHashSuffix());
 			} else {
 				$suffix = $this->getVersionHashSuffix($web, $file);
 
 				if (!str_contains($file, '?v=')) {
-					$this->append('cssfiles', $web . '/' . $file . $suffix);
+					$page->append('cssfiles', $web . '/' . $file . $suffix);
 				} else {
-					$this->append('cssfiles', $web . '/' . $file . '-' . substr($suffix, 3));
+					$page->append('cssfiles', $web . '/' . $file . '-' . substr($suffix, 3));
 				}
 			}
 		}
 
-		$request = \OCP\Server::get(IRequest::class);
 		if ($request->isUserAgent([Request::USER_AGENT_CLIENT_IOS, Request::USER_AGENT_SAFARI, Request::USER_AGENT_SAFARI_MOBILE])) {
 			// Prevent auto zoom with iOS but still allow user zoom
 			// On chrome (and others) this does not work (will also disable user zoom)
-			$this->assign('viewport_maximum_scale', '1.0');
+			$page->assign('viewport_maximum_scale', '1.0');
 		}
 
-		$this->assign('initialStates', $this->initialState->getInitialStates());
+		$page->assign('initialStates', $this->initialState->getInitialStates());
+
+		$page->assign('id-app-content', $renderAs === TemplateResponse::RENDER_AS_USER ? '#app-content' : '#content');
+		$page->assign('id-app-navigation', $renderAs === TemplateResponse::RENDER_AS_USER ? '#app-navigation' : null);
 
-		$this->assign('id-app-content', $renderAs === TemplateResponse::RENDER_AS_USER ? '#app-content' : '#content');
-		$this->assign('id-app-navigation', $renderAs === TemplateResponse::RENDER_AS_USER ? '#app-navigation' : null);
+		return $page;
 	}
 
 	protected function getVersionHashSuffix(string $path = '', string $file = ''): string {
@@ -339,7 +341,7 @@ class TemplateLayout extends \OC_Template {
 		if (array_key_exists($path, self::$cacheBusterCache) === false) {
 			// Not yet cached, so lets find the cache buster string
 			$appId = $this->getAppNamefromPath($path);
-			if ($appId === false || $appId === null) {
+			if ($appId === false) {
 				// No app Id could be guessed
 				return false;
 			}
@@ -362,11 +364,7 @@ class TemplateLayout extends \OC_Template {
 		return self::$cacheBusterCache[$path];
 	}
 
-	/**
-	 * @param array $styles
-	 * @return array
-	 */
-	public static function findStylesheetFiles($styles, $compileScss = true) {
+	public static function findStylesheetFiles(array $styles): array {
 		if (!self::$cssLocator) {
 			self::$cssLocator = \OCP\Server::get(CSSResourceLocator::class);
 		}
@@ -374,12 +372,8 @@ class TemplateLayout extends \OC_Template {
 		return self::$cssLocator->getResources();
 	}
 
-	/**
-	 * @param string $path
-	 * @return string|false
-	 */
-	public function getAppNamefromPath($path) {
-		if ($path !== '' && is_string($path)) {
+	public function getAppNamefromPath(string $path): string|false {
+		if ($path !== '') {
 			$pathParts = explode('/', $path);
 			if ($pathParts[0] === 'css') {
 				// This is a scss request
@@ -392,11 +386,7 @@ class TemplateLayout extends \OC_Template {
 		return false;
 	}
 
-	/**
-	 * @param array $scripts
-	 * @return array
-	 */
-	public static function findJavascriptFiles($scripts) {
+	public static function findJavascriptFiles(array $scripts): array {
 		if (!self::$jsLocator) {
 			self::$jsLocator = \OCP\Server::get(JSResourceLocator::class);
 		}
@@ -410,7 +400,7 @@ class TemplateLayout extends \OC_Template {
 	 * @return string Relative path
 	 * @throws \Exception If $filePath is not under \OC::$SERVERROOT
 	 */
-	public static function convertToRelativePath($filePath) {
+	public static function convertToRelativePath(string $filePath) {
 		$relativePath = explode(\OC::$SERVERROOT, $filePath);
 		if (count($relativePath) !== 2) {
 			throw new \Exception('$filePath is not under the \OC::$SERVERROOT');
diff --git a/lib/private/legacy/OC_Template.php b/lib/private/legacy/OC_Template.php
index af363e0a41e..77b25477d31 100644
--- a/lib/private/legacy/OC_Template.php
+++ b/lib/private/legacy/OC_Template.php
@@ -5,209 +5,27 @@
  * SPDX-FileCopyrightText: 2016 ownCloud, Inc.
  * SPDX-License-Identifier: AGPL-3.0-only
  */
-use OC\TemplateLayout;
-use OCP\AppFramework\Http\Events\BeforeTemplateRenderedEvent;
-use OCP\AppFramework\Http\TemplateResponse;
-use OCP\EventDispatcher\IEventDispatcher;
-use Psr\Log\LoggerInterface;
+use OCP\Server;
+use OCP\Template\ITemplateManager;
 
 require_once __DIR__ . '/template/functions.php';
 
 /**
  * This class provides the templates for ownCloud.
+ * @deprecated 32.0.0 Use \OCP\Template\ITemplateManager instead
  */
-class OC_Template extends \OC\Template\Base {
-	/** @var string */
-	private $renderAs; // Create a full page?
-
-	/** @var string */
-	private $path; // The path to the template
-
-	/** @var array */
-	private $headers = []; //custom headers
-
-	/** @var string */
-	protected $app; // app id
-
-	/**
-	 * Constructor
-	 *
-	 * @param string $app app providing the template
-	 * @param string $name of the template file (without suffix)
-	 * @param string $renderAs If $renderAs is set, OC_Template will try to
-	 *                         produce a full page in the according layout. For
-	 *                         now, $renderAs can be set to "guest", "user" or
-	 *                         "admin".
-	 * @param bool $registerCall = true
-	 */
-	public function __construct($app, $name, $renderAs = TemplateResponse::RENDER_AS_BLANK, $registerCall = true) {
-		$theme = OC_Util::getTheme();
-
-		$requestToken = (OC::$server->getSession() && $registerCall) ? \OCP\Util::callRegister() : '';
-		$cspNonce = \OCP\Server::get(\OC\Security\CSP\ContentSecurityPolicyNonceManager::class)->getNonce();
-
-		$parts = explode('/', $app); // fix translation when app is something like core/lostpassword
-		$l10n = \OC::$server->getL10N($parts[0]);
-		/** @var \OCP\Defaults $themeDefaults */
-		$themeDefaults = \OCP\Server::get(\OCP\Defaults::class);
-
-		[$path, $template] = $this->findTemplate($theme, $app, $name);
-
-		// Set the private data
-		$this->renderAs = $renderAs;
-		$this->path = $path;
-		$this->app = $app;
-
-		parent::__construct(
-			$template,
-			$requestToken,
-			$l10n,
-			$themeDefaults,
-			$cspNonce,
-		);
-	}
-
-
-	/**
-	 * find the template with the given name
-	 * @param string $name of the template file (without suffix)
-	 *
-	 * Will select the template file for the selected theme.
-	 * Checking all the possible locations.
-	 * @param string $theme
-	 * @param string $app
-	 * @return string[]
-	 */
-	protected function findTemplate($theme, $app, $name) {
-		// Check if it is a app template or not.
-		if ($app !== '') {
-			$dirs = $this->getAppTemplateDirs($theme, $app, OC::$SERVERROOT, OC_App::getAppPath($app));
-		} else {
-			$dirs = $this->getCoreTemplateDirs($theme, OC::$SERVERROOT);
-		}
-		$locator = new \OC\Template\TemplateFileLocator($dirs);
-		$template = $locator->find($name);
-		$path = $locator->getPath();
-		return [$path, $template];
-	}
-
-	/**
-	 * Add a custom element to the header
-	 * @param string $tag tag name of the element
-	 * @param array $attributes array of attributes for the element
-	 * @param string $text the text content for the element. If $text is null then the
-	 *                     element will be written as empty element. So use "" to get a closing tag.
-	 */
-	public function addHeader($tag, $attributes, $text = null) {
-		$this->headers[] = [
-			'tag' => $tag,
-			'attributes' => $attributes,
-			'text' => $text
-		];
-	}
-
-	/**
-	 * Process the template
-	 * @return string
-	 *
-	 * This function process the template. If $this->renderAs is set, it
-	 * will produce a full page.
-	 */
-	public function fetchPage($additionalParams = null) {
-		$data = parent::fetchPage($additionalParams);
-
-		if ($this->renderAs) {
-			$page = new TemplateLayout($this->renderAs, $this->app);
-
-			if (is_array($additionalParams)) {
-				foreach ($additionalParams as $key => $value) {
-					$page->assign($key, $value);
-				}
-			}
-
-			// Add custom headers
-			$headers = '';
-			foreach (OC_Util::$headers as $header) {
-				$headers .= '<' . \OCP\Util::sanitizeHTML($header['tag']);
-				if (strcasecmp($header['tag'], 'script') === 0 && in_array('src', array_map('strtolower', array_keys($header['attributes'])))) {
-					$headers .= ' defer';
-				}
-				foreach ($header['attributes'] as $name => $value) {
-					$headers .= ' ' . \OCP\Util::sanitizeHTML($name) . '="' . \OCP\Util::sanitizeHTML($value) . '"';
-				}
-				if ($header['text'] !== null) {
-					$headers .= '>' . \OCP\Util::sanitizeHTML($header['text']) . '</' . \OCP\Util::sanitizeHTML($header['tag']) . '>';
-				} else {
-					$headers .= '/>';
-				}
-			}
-
-			$page->assign('headers', $headers);
-
-			$page->assign('content', $data);
-			return $page->fetchPage($additionalParams);
-		}
-
-		return $data;
-	}
-
-	/**
-	 * Include template
-	 *
-	 * @param string $file
-	 * @param array|null $additionalParams
-	 * @return string returns content of included template
-	 *
-	 * Includes another template. use <?php echo $this->inc('template'); ?> to
-	 * do this.
-	 */
-	public function inc($file, $additionalParams = null) {
-		return $this->load($this->path . $file . '.php', $additionalParams);
-	}
-
-	/**
-	 * Shortcut to print a simple page for users
-	 * @param string $application The application we render the template for
-	 * @param string $name Name of the template
-	 * @param array $parameters Parameters for the template
-	 * @return boolean|null
-	 */
-	public static function printUserPage($application, $name, $parameters = []) {
-		$content = new OC_Template($application, $name, 'user');
-		foreach ($parameters as $key => $value) {
-			$content->assign($key, $value);
-		}
-		print $content->printPage();
-	}
-
-	/**
-	 * Shortcut to print a simple page for admins
-	 * @param string $application The application we render the template for
-	 * @param string $name Name of the template
-	 * @param array $parameters Parameters for the template
-	 * @return bool
-	 */
-	public static function printAdminPage($application, $name, $parameters = []) {
-		$content = new OC_Template($application, $name, 'admin');
-		foreach ($parameters as $key => $value) {
-			$content->assign($key, $value);
-		}
-		return $content->printPage();
-	}
-
+class OC_Template extends \OC\Template\Template {
 	/**
 	 * Shortcut to print a simple page for guests
 	 * @param string $application The application we render the template for
 	 * @param string $name Name of the template
-	 * @param array|string $parameters Parameters for the template
+	 * @param array $parameters Parameters for the template
 	 * @return bool
+	 * @deprecated 32.0.0 Use \OCP\Template\ITemplateManager instead
 	 */
 	public static function printGuestPage($application, $name, $parameters = []) {
-		$content = new OC_Template($application, $name, $name === 'error' ? $name : 'guest');
-		foreach ($parameters as $key => $value) {
-			$content->assign($key, $value);
-		}
-		return $content->printPage();
+		Server::get(ITemplateManager::class)->printGuestPage($application, $name, $parameters);
+		return true;
 	}
 
 	/**
@@ -215,123 +33,21 @@ class OC_Template extends \OC\Template\Base {
 	 * @param string $error_msg The error message to show
 	 * @param string $hint An optional hint message - needs to be properly escape
 	 * @param int $statusCode
-	 * @suppress PhanAccessMethodInternal
+	 * @return never
+	 * @deprecated 32.0.0 Use \OCP\Template\ITemplateManager instead
 	 */
 	public static function printErrorPage($error_msg, $hint = '', $statusCode = 500) {
-		if (\OC::$server->getAppManager()->isEnabledForUser('theming') && !\OC_App::isAppLoaded('theming')) {
-			\OC_App::loadApp('theming');
-		}
-
-
-		if ($error_msg === $hint) {
-			// If the hint is the same as the message there is no need to display it twice.
-			$hint = '';
-		}
-		$errors = [['error' => $error_msg, 'hint' => $hint]];
-
-		http_response_code($statusCode);
-		try {
-			// Try rendering themed html error page
-			$response = new TemplateResponse(
-				'',
-				'error',
-				['errors' => $errors],
-				TemplateResponse::RENDER_AS_ERROR,
-				$statusCode,
-			);
-			$event = new BeforeTemplateRenderedEvent(false, $response);
-			\OC::$server->get(IEventDispatcher::class)->dispatchTyped($event);
-			print($response->render());
-		} catch (\Throwable $e1) {
-			$logger = \OCP\Server::get(LoggerInterface::class);
-			$logger->error('Rendering themed error page failed. Falling back to un-themed error page.', [
-				'app' => 'core',
-				'exception' => $e1,
-			]);
-
-			try {
-				// Try rendering unthemed html error page
-				$content = new \OC_Template('', 'error', 'error', false);
-				$content->assign('errors', $errors);
-				$content->printPage();
-			} catch (\Exception $e2) {
-				// If nothing else works, fall back to plain text error page
-				$logger->error("$error_msg $hint", ['app' => 'core']);
-				$logger->error('Rendering un-themed error page failed. Falling back to plain text error page.', [
-					'app' => 'core',
-					'exception' => $e2,
-				]);
-
-				header('Content-Type: text/plain; charset=utf-8');
-				print("$error_msg $hint");
-			}
-		}
-		die();
+		Server::get(ITemplateManager::class)->printErrorPage($error_msg, $hint, $statusCode);
 	}
 
 	/**
 	 * print error page using Exception details
 	 * @param Exception|Throwable $exception
 	 * @param int $statusCode
-	 * @return bool|string
-	 * @suppress PhanAccessMethodInternal
+	 * @return never
+	 * @deprecated 32.0.0 Use \OCP\Template\ITemplateManager instead
 	 */
 	public static function printExceptionErrorPage($exception, $statusCode = 503) {
-		$debug = false;
-		http_response_code($statusCode);
-		try {
-			$debug = \OC::$server->getSystemConfig()->getValue('debug', false);
-			$serverLogsDocumentation = \OC::$server->getSystemConfig()->getValue('documentation_url.server_logs', '');
-			$request = \OC::$server->getRequest();
-			$content = new \OC_Template('', 'exception', 'error', false);
-			$content->assign('errorClass', get_class($exception));
-			$content->assign('errorMsg', $exception->getMessage());
-			$content->assign('errorCode', $exception->getCode());
-			$content->assign('file', $exception->getFile());
-			$content->assign('line', $exception->getLine());
-			$content->assign('exception', $exception);
-			$content->assign('debugMode', $debug);
-			$content->assign('serverLogsDocumentation', $serverLogsDocumentation);
-			$content->assign('remoteAddr', $request->getRemoteAddress());
-			$content->assign('requestID', $request->getId());
-			$content->printPage();
-		} catch (\Exception $e) {
-			try {
-				$logger = \OCP\Server::get(LoggerInterface::class);
-				$logger->error($exception->getMessage(), ['app' => 'core', 'exception' => $exception]);
-				$logger->error($e->getMessage(), ['app' => 'core', 'exception' => $e]);
-			} catch (Throwable $e) {
-				// no way to log it properly - but to avoid a white page of death we send some output
-				self::printPlainErrorPage($e, $debug);
-
-				// and then throw it again to log it at least to the web server error log
-				throw $e;
-			}
-
-			self::printPlainErrorPage($e, $debug);
-		}
-		die();
-	}
-
-	/**
-	 * @psalm-taint-escape has_quotes
-	 * @psalm-taint-escape html
-	 */
-	private static function fakeEscapeForPlainText(string $str): string {
-		return $str;
-	}
-
-	private static function printPlainErrorPage(\Throwable $exception, bool $debug = false): void {
-		header('Content-Type: text/plain; charset=utf-8');
-		print("Internal Server Error\n\n");
-		print("The server encountered an internal error and was unable to complete your request.\n");
-		print("Please contact the server administrator if this error reappears multiple times, please include the technical details below in your report.\n");
-		print("More details can be found in the server log.\n");
-
-		if ($debug) {
-			print("\n");
-			print($exception->getMessage() . ' ' . $exception->getFile() . ' at ' . $exception->getLine() . "\n");
-			print(self::fakeEscapeForPlainText($exception->getTraceAsString()));
-		}
+		Server::get(ITemplateManager::class)->printExceptionErrorPage($exception, $statusCode);
 	}
 }
diff --git a/lib/private/legacy/OC_Util.php b/lib/private/legacy/OC_Util.php
index bf60fed0389..36a121094cc 100644
--- a/lib/private/legacy/OC_Util.php
+++ b/lib/private/legacy/OC_Util.php
@@ -725,11 +725,10 @@ class OC_Util {
 	 * string or array of strings before displaying it on a web page.
 	 *
 	 * @param string|string[] $value
-	 * @return string|string[] an array of sanitized strings or a single sanitized string, depends on the input parameter.
+	 * @return ($value is array ? string[] : string)
 	 */
 	public static function sanitizeHTML($value) {
 		if (is_array($value)) {
-			/** @var string[] $value */
 			$value = array_map(function ($value) {
 				return self::sanitizeHTML($value);
 			}, $value);
diff --git a/lib/public/AppFramework/Http/TemplateResponse.php b/lib/public/AppFramework/Http/TemplateResponse.php
index 55b9f2b06af..af37a1a2313 100644
--- a/lib/public/AppFramework/Http/TemplateResponse.php
+++ b/lib/public/AppFramework/Http/TemplateResponse.php
@@ -1,13 +1,19 @@
 <?php
 
+declare(strict_types=1);
+
+
 /**
  * SPDX-FileCopyrightText: 2016-2024 Nextcloud GmbH and Nextcloud contributors
  * SPDX-FileCopyrightText: 2016 ownCloud, Inc.
  * SPDX-License-Identifier: AGPL-3.0-only
  */
+
 namespace OCP\AppFramework\Http;
 
 use OCP\AppFramework\Http;
+use OCP\Server;
+use OCP\Template\ITemplateManager;
 
 /**
  * Response for a normal template
@@ -180,7 +186,7 @@ class TemplateResponse extends Response {
 			$renderAs = $this->renderAs;
 		}
 
-		$template = new \OCP\Template($this->appName, $this->templateName, $renderAs);
+		$template = Server::get(ITemplateManager::class)->getTemplate($this->appName, $this->templateName, $renderAs);
 
 		foreach ($this->params as $key => $value) {
 			$template->assign($key, $value);
diff --git a/lib/public/AppFramework/Http/TooManyRequestsResponse.php b/lib/public/AppFramework/Http/TooManyRequestsResponse.php
index 6b2ef5b1b90..f7084ec768d 100644
--- a/lib/public/AppFramework/Http/TooManyRequestsResponse.php
+++ b/lib/public/AppFramework/Http/TooManyRequestsResponse.php
@@ -8,7 +8,8 @@ declare(strict_types=1);
 namespace OCP\AppFramework\Http;
 
 use OCP\AppFramework\Http;
-use OCP\Template;
+use OCP\Server;
+use OCP\Template\ITemplateManager;
 
 /**
  * A generic 429 response showing an 404 error page as well to the end-user
@@ -34,7 +35,7 @@ class TooManyRequestsResponse extends Response {
 	 * @since 19.0.0
 	 */
 	public function render() {
-		$template = new Template('core', '429', 'blank');
+		$template = Server::get(ITemplateManager::class)->getTemplate('core', '429', TemplateResponse::RENDER_AS_BLANK);
 		return $template->fetchPage();
 	}
 }
diff --git a/lib/public/Authentication/TwoFactorAuth/ILoginSetupProvider.php b/lib/public/Authentication/TwoFactorAuth/ILoginSetupProvider.php
index 84b0a9066f2..32ede4f385c 100644
--- a/lib/public/Authentication/TwoFactorAuth/ILoginSetupProvider.php
+++ b/lib/public/Authentication/TwoFactorAuth/ILoginSetupProvider.php
@@ -8,16 +8,15 @@ declare(strict_types=1);
  */
 namespace OCP\Authentication\TwoFactorAuth;
 
-use OCP\Template;
+use OCP\Template\ITemplate;
 
 /**
  * @since 17.0.0
  */
 interface ILoginSetupProvider {
 	/**
-	 * @return Template
-	 *
 	 * @since 17.0.0
+	 * @since 32.0.0 Broader return type ITemplate instead of \OCP\Template
 	 */
-	public function getBody(): Template;
+	public function getBody(): ITemplate;
 }
diff --git a/lib/public/Authentication/TwoFactorAuth/IPersonalProviderSettings.php b/lib/public/Authentication/TwoFactorAuth/IPersonalProviderSettings.php
index 610f299c526..3cf7946272e 100644
--- a/lib/public/Authentication/TwoFactorAuth/IPersonalProviderSettings.php
+++ b/lib/public/Authentication/TwoFactorAuth/IPersonalProviderSettings.php
@@ -6,9 +6,10 @@ declare(strict_types=1);
  * SPDX-FileCopyrightText: 2016 Nextcloud GmbH and Nextcloud contributors
  * SPDX-License-Identifier: AGPL-3.0-or-later
  */
+
 namespace OCP\Authentication\TwoFactorAuth;
 
-use OCP\Template;
+use OCP\Template\ITemplate;
 
 /**
  * Interface IPersonalProviderSettings
@@ -17,9 +18,8 @@ use OCP\Template;
  */
 interface IPersonalProviderSettings {
 	/**
-	 * @return Template
-	 *
 	 * @since 15.0.0
+	 * @since 32.0.0 Broader return type ITemplate instead of \OCP\Template
 	 */
-	public function getBody(): Template;
+	public function getBody(): ITemplate;
 }
diff --git a/lib/public/Authentication/TwoFactorAuth/IProvider.php b/lib/public/Authentication/TwoFactorAuth/IProvider.php
index f1dd24ff0a2..27c4121f4ac 100644
--- a/lib/public/Authentication/TwoFactorAuth/IProvider.php
+++ b/lib/public/Authentication/TwoFactorAuth/IProvider.php
@@ -9,7 +9,7 @@ declare(strict_types=1);
 namespace OCP\Authentication\TwoFactorAuth;
 
 use OCP\IUser;
-use OCP\Template;
+use OCP\Template\ITemplate;
 
 /**
  * @since 9.1.0
@@ -50,11 +50,9 @@ interface IProvider {
 	 * Get the template for rending the 2FA provider view
 	 *
 	 * @since 9.1.0
-	 *
-	 * @param IUser $user
-	 * @return Template
+	 * @since 32.0.0 Broader return type ITemplate instead of \OCP\Template.
 	 */
-	public function getTemplate(IUser $user): Template;
+	public function getTemplate(IUser $user): ITemplate;
 
 	/**
 	 * Verify the given challenge
diff --git a/lib/public/Template.php b/lib/public/Template.php
index 048697ffcc4..d9b3083319b 100644
--- a/lib/public/Template.php
+++ b/lib/public/Template.php
@@ -12,6 +12,7 @@ namespace OCP;
  * specific templates, add data and generate the html code
  *
  * @since 8.0.0
+ * @deprecated 32.0.0 Use \OCP\Template\ITemplateManager instead
  */
 class Template extends \OC_Template {
 	/**
diff --git a/lib/public/Template/ITemplate.php b/lib/public/Template/ITemplate.php
new file mode 100644
index 00000000000..7131df4d17c
--- /dev/null
+++ b/lib/public/Template/ITemplate.php
@@ -0,0 +1,47 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * SPDX-FileCopyrightText: 2025 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+namespace OCP\Template;
+
+/**
+ * @since 32.0.0
+ */
+interface ITemplate {
+	/**
+	 * Process the template
+	 * @since 32.0.0
+	 */
+	public function fetchPage(?array $additionalParams = null): string;
+
+	/**
+	 * Proceed the template and print its output.
+	 * @since 32.0.0
+	 */
+	public function printPage(): void;
+
+	/**
+	 * Assign variables
+	 *
+	 * This function assigns a variable. It can be accessed via $_[$key] in
+	 * the template.
+	 *
+	 * If the key existed before, it will be overwritten
+	 * @since 32.0.0
+	 */
+	public function assign(string $key, mixed $value): void;
+
+	/**
+	 * Appends a variable
+	 *
+	 * This function assigns a variable in an array context. If the key already
+	 * exists, the value will be appended. It can be accessed via
+	 * $_[$key][$position] in the template.
+	 */
+	public function append(string $key, mixed $value): void;
+}
diff --git a/lib/public/Template/ITemplateManager.php b/lib/public/Template/ITemplateManager.php
new file mode 100644
index 00000000000..05549bbddfd
--- /dev/null
+++ b/lib/public/Template/ITemplateManager.php
@@ -0,0 +1,44 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * SPDX-FileCopyrightText: 2025 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+namespace OCP\Template;
+
+use OCP\AppFramework\Http\TemplateResponse;
+
+/**
+ * @since 32.0.0
+ */
+interface ITemplateManager {
+	/**
+	 * @param TemplateResponse::RENDER_AS_* $renderAs
+	 * @throws TemplateNotFoundException if the template cannot be found
+	 * @since 32.0.0
+	 */
+	public function getTemplate(string $app, string $name, string $renderAs = TemplateResponse::RENDER_AS_BLANK, bool $registerCall = true): ITemplate;
+
+	/**
+	 * Shortcut to print a simple page for guests
+	 * @since 32.0.0
+	 */
+	public function printGuestPage(string $application, string $name, array $parameters = []): void;
+
+	/**
+	 * Print a fatal error page and terminates the script
+	 * @since 32.0.0
+	 * @param string $error_msg The error message to show
+	 * @param string $hint An optional hint message - needs to be properly escape
+	 */
+	public function printErrorPage(string $error_msg, string $hint = '', int $statusCode = 500): never;
+
+	/**
+	 * Print error page using Exception details
+	 * @since 32.0.0
+	 */
+	public function printExceptionErrorPage(\Throwable $exception, int $statusCode = 503): never;
+}
diff --git a/lib/public/Template/TemplateNotFoundException.php b/lib/public/Template/TemplateNotFoundException.php
new file mode 100644
index 00000000000..e77fcd8646a
--- /dev/null
+++ b/lib/public/Template/TemplateNotFoundException.php
@@ -0,0 +1,16 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * SPDX-FileCopyrightText: 2025 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+namespace OCP\Template;
+
+/**
+ * @since 32.0.0
+ */
+class TemplateNotFoundException extends \Exception {
+}
diff --git a/lib/public/Util.php b/lib/public/Util.php
index 28da91c9a0f..65776bd15a7 100644
--- a/lib/public/Util.php
+++ b/lib/public/Util.php
@@ -107,7 +107,7 @@ class Util {
 	 * @param string $file
 	 * @since 4.0.0
 	 */
-	public static function addStyle($application, $file = null) {
+	public static function addStyle($application, $file = null): void {
 		\OC_Util::addStyle($application, $file);
 	}
 
@@ -384,7 +384,7 @@ class Util {
 
 	/**
 	 * Cached encrypted CSRF token. Some static unit-tests of ownCloud compare
-	 * multiple OC_Template elements which invoke `callRegister`. If the value
+	 * multiple Template elements which invoke `callRegister`. If the value
 	 * would not be cached these unit-tests would fail.
 	 * @var string
 	 */
@@ -393,6 +393,7 @@ class Util {
 	/**
 	 * Register an get/post call. This is important to prevent CSRF attacks
 	 * @since 4.5.0
+	 * @deprecated 32.0.0 directly use CsrfTokenManager instead
 	 */
 	public static function callRegister() {
 		if (self::$token === '') {
@@ -408,7 +409,7 @@ class Util {
 	 * string or array of strings before displaying it on a web page.
 	 *
 	 * @param string|string[] $value
-	 * @return string|string[] an array of sanitized strings or a single sanitized string, depends on the input parameter.
+	 * @return ($value is array ? string[] : string) an array of sanitized strings or a single sanitized string, depends on the input parameter.
 	 * @since 4.5.0
 	 */
 	public static function sanitizeHTML($value) {
diff --git a/public.php b/public.php
index 9443367eb12..682d5cb2538 100644
--- a/public.php
+++ b/public.php
@@ -14,6 +14,7 @@ use OCP\App\IAppManager;
 use OCP\IConfig;
 use OCP\IRequest;
 use OCP\Server;
+use OCP\Template\ITemplateManager;
 use OCP\Util;
 use Psr\Log\LoggerInterface;
 
@@ -92,9 +93,9 @@ try {
 	}
 	//show the user a detailed error page
 	Server::get(LoggerInterface::class)->error($ex->getMessage(), ['app' => 'public', 'exception' => $ex]);
-	OC_Template::printExceptionErrorPage($ex, $status);
+	Server::get(ITemplateManager::class)->printExceptionErrorPage($ex, $status);
 } catch (Error $ex) {
 	//show the user a detailed error page
 	Server::get(LoggerInterface::class)->error($ex->getMessage(), ['app' => 'public', 'exception' => $ex]);
-	OC_Template::printExceptionErrorPage($ex, 500);
+	Server::get(ITemplateManager::class)->printExceptionErrorPage($ex, 500);
 }
diff --git a/remote.php b/remote.php
index f63fd49354a..7058e7aceb4 100644
--- a/remote.php
+++ b/remote.php
@@ -9,6 +9,8 @@ require_once __DIR__ . '/lib/versioncheck.php';
 
 use OCA\DAV\Connector\Sabre\ExceptionLoggerPlugin;
 use OCP\App\IAppManager;
+use OCP\IRequest;
+use OCP\Template\ITemplateManager;
 use Psr\Log\LoggerInterface;
 use Sabre\DAV\Exception\ServiceUnavailable;
 use Sabre\DAV\Server;
@@ -23,7 +25,7 @@ class RemoteException extends \Exception {
 
 function handleException(Exception|Error $e): void {
 	try {
-		$request = \OC::$server->getRequest();
+		$request = \OCP\Server::get(IRequest::class);
 		// in case the request content type is text/xml - we assume it's a WebDAV request
 		$isXmlContentType = strpos($request->getHeader('Content-Type'), 'text/xml');
 		if ($isXmlContentType === 0) {
@@ -31,7 +33,7 @@ function handleException(Exception|Error $e): void {
 			$server = new Server();
 			if (!($e instanceof RemoteException)) {
 				// we shall not log on RemoteException
-				$server->addPlugin(new ExceptionLoggerPlugin('webdav', \OC::$server->get(LoggerInterface::class)));
+				$server->addPlugin(new ExceptionLoggerPlugin('webdav', \OCP\Server::get(LoggerInterface::class)));
 			}
 			$server->on('beforeMethod:*', function () use ($e) {
 				if ($e instanceof RemoteException) {
@@ -54,19 +56,19 @@ function handleException(Exception|Error $e): void {
 			}
 			if ($e instanceof RemoteException) {
 				// we shall not log on RemoteException
-				OC_Template::printErrorPage($e->getMessage(), '', $e->getCode());
+				\OCP\Server::get(ITemplateManager::class)->printErrorPage($e->getMessage(), '', $e->getCode());
 			} else {
-				\OC::$server->get(LoggerInterface::class)->error($e->getMessage(), ['app' => 'remote','exception' => $e]);
-				OC_Template::printExceptionErrorPage($e, $statusCode);
+				\OCP\Server::get(LoggerInterface::class)->error($e->getMessage(), ['app' => 'remote','exception' => $e]);
+				\OCP\Server::get(ITemplateManager::class)->printExceptionErrorPage($e, $statusCode);
 			}
 		}
 	} catch (\Exception $e) {
-		OC_Template::printExceptionErrorPage($e, 500);
+		\OCP\Server::get(ITemplateManager::class)->printExceptionErrorPage($e, 500);
 	}
 }
 
 /**
- * @param $service
+ * @param string $service
  * @return string
  */
 function resolveService($service) {
diff --git a/tests/Core/Controller/TwoFactorChallengeControllerTest.php b/tests/Core/Controller/TwoFactorChallengeControllerTest.php
index 11e18bd622a..7498abb9a9e 100644
--- a/tests/Core/Controller/TwoFactorChallengeControllerTest.php
+++ b/tests/Core/Controller/TwoFactorChallengeControllerTest.php
@@ -22,7 +22,7 @@ use OCP\ISession;
 use OCP\IURLGenerator;
 use OCP\IUser;
 use OCP\IUserSession;
-use OCP\Template;
+use OCP\Template\ITemplate;
 use Psr\Log\LoggerInterface;
 use Test\TestCase;
 
@@ -115,7 +115,7 @@ class TwoFactorChallengeControllerTest extends TestCase {
 		$provider->method('getId')->willReturn('myprovider');
 		$backupProvider = $this->createMock(IProvider::class);
 		$backupProvider->method('getId')->willReturn('backup_codes');
-		$tmpl = $this->createMock(Template::class);
+		$tmpl = $this->createMock(ITemplate::class);
 		$providerSet = new ProviderSet([$provider, $backupProvider], true);
 
 		$this->userSession->expects($this->once())
@@ -399,7 +399,7 @@ class TwoFactorChallengeControllerTest extends TestCase {
 			->method('getLoginSetup')
 			->with($user)
 			->willReturn($loginSetup);
-		$tmpl = $this->createMock(Template::class);
+		$tmpl = $this->createMock(ITemplate::class);
 		$loginSetup->expects($this->once())
 			->method('getBody')
 			->willReturn($tmpl);
diff --git a/tests/lib/TemplateLayoutTest.php b/tests/lib/TemplateLayoutTest.php
index 405f1df7330..29e31b3f391 100644
--- a/tests/lib/TemplateLayoutTest.php
+++ b/tests/lib/TemplateLayoutTest.php
@@ -14,50 +14,69 @@ use OC\TemplateLayout;
 use OCP\App\IAppManager;
 use OCP\AppFramework\Http\TemplateResponse;
 use OCP\IConfig;
+use OCP\INavigationManager;
+use OCP\Template\ITemplateManager;
+use PHPUnit\Framework\MockObject\MockObject;
 
 class TemplateLayoutTest extends \Test\TestCase {
-
+	private IConfig&MockObject $config;
+	private IAppManager&MockObject $appManager;
+	private InitialStateService&MockObject $initialState;
+	private INavigationManager&MockObject $navigationManager;
+	private ITemplateManager&MockObject $templateManager;
+
+	private TemplateLayout $templateLayout;
+
+	protected function setUp(): void {
+		parent::setUp();
+
+		$this->config = $this->createMock(IConfig::class);
+		$this->appManager = $this->createMock(IAppManager::class);
+		$this->initialState = $this->createMock(InitialStateService::class);
+		$this->navigationManager = $this->createMock(INavigationManager::class);
+		$this->templateManager = $this->createMock(ITemplateManager::class);
+	}
 
 	/** @dataProvider dataVersionHash */
 	public function testVersionHash($path, $file, $installed, $debug, $expected): void {
-		$appManager = $this->createMock(IAppManager::class);
-		$appManager->expects(self::any())
+		$this->appManager->expects(self::any())
 			->method('getAppVersion')
 			->willReturnCallback(fn ($appId) => match ($appId) {
 				'shippedApp' => 'shipped_1',
 				'otherApp' => 'other_2',
 				default => "$appId",
 			});
-		$appManager->expects(self::any())
+		$this->appManager->expects(self::any())
 			->method('isShipped')
 			->willReturnCallback(fn (string $app) => $app === 'shippedApp');
 
-		$config = $this->createMock(IConfig::class);
-		$config->expects(self::atLeastOnce())
+		$this->config->expects(self::atLeastOnce())
 			->method('getSystemValueBool')
 			->willReturnMap([
 				['installed', false, $installed],
 				['debug', false, $debug],
 			]);
-		$config->expects(self::any())
+		$this->config->expects(self::any())
 			->method('getAppValue')
 			->with('theming', 'cachebuster', '0')
 			->willReturn('42');
 
-		$initialState = $this->createMock(InitialStateService::class);
-
-		$this->overwriteService(IConfig::class, $config);
-		$this->overwriteService(IAppManager::class, $appManager);
-		$this->overwriteService(InitialStateService::class, $initialState);
-
-		$layout = $this->getMockBuilder(TemplateLayout::class)
+		$this->templateLayout = $this->getMockBuilder(TemplateLayout::class)
 			->onlyMethods(['getAppNamefromPath'])
-			->setConstructorArgs([TemplateResponse::RENDER_AS_ERROR])
+			->setConstructorArgs([
+				$this->config,
+				$this->appManager,
+				$this->initialState,
+				$this->navigationManager,
+				$this->templateManager,
+			])
 			->getMock();
 
+		$layout = $this->templateLayout->getPageTemplate(TemplateResponse::RENDER_AS_ERROR, '');
+
 		self::invokePrivate(TemplateLayout::class, 'versionHash', ['version_hash']);
 
-		$layout->expects(self::any())
+		$this->templateLayout->expects(self::any())
 			->method('getAppNamefromPath')
 			->willReturnCallback(fn ($appName) => match($appName) {
 				'apps/shipped' => 'shippedApp',
@@ -65,7 +84,7 @@ class TemplateLayoutTest extends \Test\TestCase {
 				default => false,
 			});
 
-		$hash = self::invokePrivate($layout, 'getVersionHashSuffix', [$path, $file]);
+		$hash = self::invokePrivate($this->templateLayout, 'getVersionHashSuffix', [$path, $file]);
 		self::assertEquals($expected, $hash);
 	}