2 files changed, 64 insertions, 8 deletions

diff --git a/apps/theming/lib/Service/ThemesService.php b/apps/theming/lib/Service/ThemesService.php
index d6e14b6ffcb..653b895be2c 100644
--- a/apps/theming/lib/Service/ThemesService.php
+++ b/apps/theming/lib/Service/ThemesService.php
@@ -16,24 +16,22 @@ use OCA\Theming\Themes\LightTheme;
 use OCP\IConfig;
 use OCP\IUser;
 use OCP\IUserSession;
+use Psr\Log\LoggerInterface;
 
 class ThemesService {
-	private IUserSession $userSession;
-	private IConfig $config;
-
 	/** @var ITheme[] */
 	private array $themesProviders;
 
-	public function __construct(IUserSession $userSession,
-		IConfig $config,
-		DefaultTheme $defaultTheme,
+	public function __construct(
+		private IUserSession $userSession,
+		private IConfig $config,
+		private LoggerInterface $logger,
+		private DefaultTheme $defaultTheme,
 		LightTheme $lightTheme,
 		DarkTheme $darkTheme,
 		HighContrastTheme $highContrastTheme,
 		DarkHighContrastTheme $darkHighContrastTheme,
 		DyslexiaFont $dyslexiaFont) {
-		$this->userSession = $userSession;
-		$this->config = $config;
 
 		// Register themes
 		$this->themesProviders = [
@@ -52,6 +50,22 @@ class ThemesService {
 	 * @return ITheme[]
 	 */
 	public function getThemes(): array {
+		// Enforced theme if configured
+		$enforcedTheme = $this->config->getSystemValueString('enforce_theme', '');
+		if ($enforcedTheme !== '') {
+			if (!isset($this->themesProviders[$enforcedTheme])) {
+				$this->logger->error('Enforced theme not found', ['theme' => $enforcedTheme]);
+				return $this->themesProviders;
+			}
+
+			$defaultTheme = $this->themesProviders[$this->defaultTheme->getId()];
+			$theme = $this->themesProviders[$enforcedTheme];
+			return [
+				$defaultTheme->getId() => $defaultTheme,
+				$theme->getId() => $theme,
+			];
+		}
+
 		return $this->themesProviders;
 	}
 
diff --git a/apps/theming/tests/Service/ThemesServiceTest.php b/apps/theming/tests/Service/ThemesServiceTest.php
index 29bc026820a..a670ab3a583 100644
--- a/apps/theming/tests/Service/ThemesServiceTest.php
+++ b/apps/theming/tests/Service/ThemesServiceTest.php
@@ -24,6 +24,7 @@ use OCP\IURLGenerator;
 use OCP\IUser;
 use OCP\IUserSession;
 use PHPUnit\Framework\MockObject\MockObject;
+use Psr\Log\LoggerInterface;
 use Test\TestCase;
 
 class ThemesServiceTest extends TestCase {
@@ -34,6 +35,9 @@ class ThemesServiceTest extends TestCase {
 	private $userSession;
 	/** @var IConfig|MockObject */
 	private $config;
+	/** @var LoggerInterface|MockObject */
+	private $logger;
+
 	/** @var ThemingDefaults|MockObject */
 	private $themingDefaults;
 
@@ -43,6 +47,7 @@ class ThemesServiceTest extends TestCase {
 	protected function setUp(): void {
 		$this->userSession = $this->createMock(IUserSession::class);
 		$this->config = $this->createMock(IConfig::class);
+		$this->logger = $this->createMock(LoggerInterface::class);
 		$this->themingDefaults = $this->createMock(ThemingDefaults::class);
 
 		$this->themingDefaults->expects($this->any())
@@ -58,6 +63,7 @@ class ThemesServiceTest extends TestCase {
 		$this->themesService = new ThemesService(
 			$this->userSession,
 			$this->config,
+			$this->logger,
 			...array_values($this->themes)
 		);
 
@@ -76,6 +82,42 @@ class ThemesServiceTest extends TestCase {
 		$this->assertEquals($expected, array_keys($this->themesService->getThemes()));
 	}
 
+	public function testGetThemesEnforced() {
+		$this->config->expects($this->once())
+			->method('getSystemValueString')
+			->with('enforce_theme', '')
+			->willReturn('dark');
+		$this->logger->expects($this->never())
+			->method('error');
+
+		$expected = [
+			'default',
+			'dark',
+		];
+
+		$this->assertEquals($expected, array_keys($this->themesService->getThemes()));
+	}
+
+	public function testGetThemesEnforcedInvalid() {
+		$this->config->expects($this->once())
+			->method('getSystemValueString')
+			->with('enforce_theme', '')
+			->willReturn('invalid');
+		$this->logger->expects($this->once())
+			->method('error')
+			->with('Enforced theme not found', ['theme' => 'invalid']);
+
+		$expected = [
+			'default',
+			'light',
+			'dark',
+			'light-highcontrast',
+			'dark-highcontrast',
+			'opendyslexic',
+		];
+
+		$this->assertEquals($expected, array_keys($this->themesService->getThemes()));
+	}
 
 	public function dataTestEnableTheme() {
 		return [