[WIP] legacy sharing backend

apps/files_sharing/composer/composer/autoload_classmap.php

@@ -93,6 +93,8 @@
     'OCA\\Files_Sharing\\Migration\\Version33000Date20251030081948' => $baseDir . '/../lib/Migration/Version33000Date20251030081948.php',
     'OCA\\Files_Sharing\\Migration\\Version33000Date20260306120000' => $baseDir . '/../lib/Migration/Version33000Date20260306120000.php',
     'OCA\\Files_Sharing\\Migration\\Version33000Date20260306150000' => $baseDir . '/../lib/Migration/Version33000Date20260306150000.php',
+    'OCA\\Files_Sharing\\Migration\\Version35000Date20260720121254' => $baseDir . '/../lib/Migration/Version35000Date20260720121254.php',
+    'OCA\\Files_Sharing\\Migration\\Version35000Date20260813121254' => $baseDir . '/../lib/Migration/Version35000Date20260813121254.php',
     'OCA\\Files_Sharing\\MountProvider' => $baseDir . '/../lib/MountProvider.php',
     'OCA\\Files_Sharing\\Notification\\Listener' => $baseDir . '/../lib/Notification/Listener.php',
     'OCA\\Files_Sharing\\Notification\\Notifier' => $baseDir . '/../lib/Notification/Notifier.php',
@@ -107,6 +109,7 @@
     'OCA\\Files_Sharing\\SharedMount' => $baseDir . '/../lib/SharedMount.php',
     'OCA\\Files_Sharing\\SharedStorage' => $baseDir . '/../lib/SharedStorage.php',
     'OCA\\Files_Sharing\\SharesReminderJob' => $baseDir . '/../lib/SharesReminderJob.php',
+    'OCA\\Files_Sharing\\Sharing\\LegacyBackend' => $baseDir . '/../lib/Sharing/LegacyBackend.php',
     'OCA\\Files_Sharing\\Updater' => $baseDir . '/../lib/Updater.php',
     'OCA\\Files_Sharing\\ViewOnly' => $baseDir . '/../lib/ViewOnly.php',
 );

apps/files_sharing/composer/composer/autoload_static.php

@@ -108,6 +108,8 @@ class ComposerStaticInitFiles_Sharing
         'OCA\\Files_Sharing\\Migration\\Version33000Date20251030081948' => __DIR__ . '/..' . '/../lib/Migration/Version33000Date20251030081948.php',
         'OCA\\Files_Sharing\\Migration\\Version33000Date20260306120000' => __DIR__ . '/..' . '/../lib/Migration/Version33000Date20260306120000.php',
         'OCA\\Files_Sharing\\Migration\\Version33000Date20260306150000' => __DIR__ . '/..' . '/../lib/Migration/Version33000Date20260306150000.php',
+        'OCA\\Files_Sharing\\Migration\\Version35000Date20260720121254' => __DIR__ . '/..' . '/../lib/Migration/Version35000Date20260720121254.php',
+        'OCA\\Files_Sharing\\Migration\\Version35000Date20260813121254' => __DIR__ . '/..' . '/../lib/Migration/Version35000Date20260813121254.php',
         'OCA\\Files_Sharing\\MountProvider' => __DIR__ . '/..' . '/../lib/MountProvider.php',
         'OCA\\Files_Sharing\\Notification\\Listener' => __DIR__ . '/..' . '/../lib/Notification/Listener.php',
         'OCA\\Files_Sharing\\Notification\\Notifier' => __DIR__ . '/..' . '/../lib/Notification/Notifier.php',
@@ -122,6 +124,7 @@ class ComposerStaticInitFiles_Sharing
         'OCA\\Files_Sharing\\SharedMount' => __DIR__ . '/..' . '/../lib/SharedMount.php',
         'OCA\\Files_Sharing\\SharedStorage' => __DIR__ . '/..' . '/../lib/SharedStorage.php',
         'OCA\\Files_Sharing\\SharesReminderJob' => __DIR__ . '/..' . '/../lib/SharesReminderJob.php',
+        'OCA\\Files_Sharing\\Sharing\\LegacyBackend' => __DIR__ . '/..' . '/../lib/Sharing/LegacyBackend.php',
         'OCA\\Files_Sharing\\Updater' => __DIR__ . '/..' . '/../lib/Updater.php',
         'OCA\\Files_Sharing\\ViewOnly' => __DIR__ . '/..' . '/../lib/ViewOnly.php',
     );

apps/files_sharing/lib/AppInfo/Application.php

@@ -8,6 +8,7 @@
 
 namespace OCA\Files_Sharing\AppInfo;
 
+use NCU\Sharing\ISharingRegistry;
 use OC\Group\DisplayNameCache as GroupDisplayNameCache;
 use OC\User\DisplayNameCache;
 use OCA\Files\Event\LoadAdditionalScriptsEvent;
@@ -36,6 +37,7 @@
 use OCA\Files_Sharing\MountProvider;
 use OCA\Files_Sharing\Notification\Listener;
 use OCA\Files_Sharing\Notification\Notifier;
+use OCA\Files_Sharing\Sharing\LegacyBackend;
 use OCP\AppFramework\App;
 use OCP\AppFramework\Bootstrap\IBootContext;
 use OCP\AppFramework\Bootstrap\IBootstrap;
@@ -58,6 +60,7 @@
 use OCP\IDBConnection;
 use OCP\IGroup;
 use OCP\Interaction\RestrictInteractionEvent;
+use OCP\Server;
 use OCP\Share\Events\BeforeShareDeletedEvent;
 use OCP\Share\Events\ShareCreatedEvent;
 use OCP\Share\Events\ShareMovedEvent;
@@ -136,6 +139,9 @@ function () use ($c) {
 		$context->registerConfigLexicon(ConfigLexicon::class);
 
 		$context->registerEventListener(RestrictInteractionEvent::class, RestrictInteractionListener::class);
+
+		$registry = Server::get(ISharingRegistry::class);
+		$registry->registerLegacyBackend(Server::get(LegacyBackend::class));
 	}
 
 	#[\Override]

apps/files_sharing/lib/Migration/Version35000Date20260720121254.php

@@ -0,0 +1,34 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * SPDX-FileCopyrightText: 2026 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+namespace OCA\Files_Sharing\Migration;
+
+use Closure;
+use OCP\DB\ISchemaWrapper;
+use OCP\DB\Types;
+use OCP\Migration\IOutput;
+use OCP\Migration\SimpleMigrationStep;
+use Override;
+
+class Version35000Date20260720121254 extends SimpleMigrationStep {
+	#[Override]
+	public function changeSchema(IOutput $output, Closure $schemaClosure, array $options): ?ISchemaWrapper {
+		/** @var ISchemaWrapper $schema */
+		$schema = $schemaClosure();
+
+		$shareLegacyMappingTable = $schema->createTable('share_legacy_mapping');
+		$shareLegacyMappingTable->addColumn('id', Types::BIGINT);
+		$shareLegacyMappingTable->addColumn('legacy_provider', Types::STRING, ['length' => 128]);
+		$shareLegacyMappingTable->addColumn('legacy_id', Types::STRING, ['length' => 128]);
+		$shareLegacyMappingTable->setPrimaryKey(['id']);
+		$shareLegacyMappingTable->addUniqueIndex(['legacy_provider', 'legacy_id']);
+
+		return null;
+	}
+}

apps/files_sharing/lib/Migration/Version35000Date20260813121254.php

@@ -0,0 +1,43 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * SPDX-FileCopyrightText: 2026 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+namespace OCA\Files_Sharing\Migration;
+
+use Closure;
+use OCP\DB\ISchemaWrapper;
+use OCP\DB\Types;
+use OCP\Migration\Attributes\AddColumn;
+use OCP\Migration\Attributes\AddIndex;
+use OCP\Migration\Attributes\CreateTable;
+use OCP\Migration\Attributes\DropColumn;
+use OCP\Migration\Attributes\DropIndex;
+use OCP\Migration\Attributes\IndexType;
+use OCP\Migration\IOutput;
+use OCP\Migration\SimpleMigrationStep;
+use Override;
+
+#[CreateTable(table: 'sharing_classmap')]
+#[DropIndex(table: 'share_legacy_mapping', type: IndexType::PRIMARY)]
+#[DropIndex(table: 'share_legacy_mapping', type: IndexType::UNIQUE)]
+#[AddIndex(table: 'share_legacy_mapping', type: IndexType::PRIMARY)]
+#[AddIndex(table: 'share_legacy_mapping', type: IndexType::INDEX)]
+class Version35000Date20260813121254 extends SimpleMigrationStep {
+	#[Override]
+	public function changeSchema(IOutput $output, Closure $schemaClosure, array $options): ?ISchemaWrapper {
+		/** @var ISchemaWrapper $schema */
+		$schema = $schemaClosure();
+
+		$shareLegacyMappingTable = $schema->getTable('share_legacy_mapping');
+		$shareLegacyMappingTable->dropPrimaryKey();
+		$shareLegacyMappingTable->setPrimaryKey(['legacy_provider', 'legacy_id']);
+		$shareLegacyMappingTable->addIndex(['id']);
+
+		return null;
+	}
+}