extend the reference API for the new link picker

- add 2 interfaces for discoverable and searchable reference providers
- new OCS route to get info on discoverable/searchable reference providers
- new abstract ADiscoverableReferenceProvider that only implements jsonSerialize
- listen to RenderReferenceEvent to inject provider list with initial state

Signed-off-by: Julien Veyssier <julien-nc@posteo.net>

9 files changed, 295 insertions, 0 deletions

diff --git a/core/Controller/ReferenceApiController.php b/core/Controller/ReferenceApiController.php
index 266532113d8..098940187a8 100644
--- a/core/Controller/ReferenceApiController.php
+++ b/core/Controller/ReferenceApiController.php
@@ -25,6 +25,7 @@ declare(strict_types=1);
 namespace OC\Core\Controller;
 
 use OCP\AppFramework\Http\DataResponse;
+use OCP\Collaboration\Reference\IDiscoverableReferenceProvider;
 use OCP\Collaboration\Reference\IReferenceManager;
 use OCP\IRequest;
 
@@ -88,4 +89,17 @@ class ReferenceApiController extends \OCP\AppFramework\OCSController {
 			'references' => array_filter($result)
 		]);
 	}
+
+	/**
+	 * @NoAdminRequired
+	 *
+	 * @return DataResponse
+	 */
+	public function getProvidersInfo(): DataResponse {
+		$providers = $this->referenceManager->getDiscoverableProviders();
+		$jsonProviders = array_map(static function (IDiscoverableReferenceProvider $provider) {
+			return $provider->jsonSerialize();
+		}, $providers);
+		return new DataResponse($jsonProviders);
+	}
 }
diff --git a/core/routes.php b/core/routes.php
index a3fdfafd7bf..4b67dee43f9 100644
--- a/core/routes.php
+++ b/core/routes.php
@@ -134,6 +134,7 @@ $application->registerRoutes($this, [
 		['root' => '/references', 'name' => 'ReferenceApi#resolveOne', 'url' => '/resolve', 'verb' => 'GET'],
 		['root' => '/references', 'name' => 'ReferenceApi#extract', 'url' => '/extract', 'verb' => 'POST'],
 		['root' => '/references', 'name' => 'ReferenceApi#resolve', 'url' => '/resolve', 'verb' => 'POST'],
+		['root' => '/references', 'name' => 'ReferenceApi#getProvidersInfo', 'url' => '/providers', 'verb' => 'GET'],
 
 		['root' => '/profile', 'name' => 'ProfileApi#setVisibility', 'url' => '/{targetUserId}', 'verb' => 'PUT'],
 
diff --git a/lib/base.php b/lib/base.php
index 6186e29bd6d..b5c5845b5a0 100644
--- a/lib/base.php
+++ b/lib/base.php
@@ -762,6 +762,7 @@ class OC {
 		self::registerAccountHooks();
 		self::registerResourceCollectionHooks();
 		self::registerFileReferenceEventListener();
+		self::registerRenderReferenceEventListener();
 		self::registerAppRestrictionsHooks();
 
 		// Make sure that the application class is not loaded before the database is setup
@@ -925,6 +926,10 @@ class OC {
 		\OC\Collaboration\Reference\File\FileReferenceEventListener::register(Server::get(IEventDispatcher::class));
 	}
 
+	private static function registerRenderReferenceEventListener() {
+		\OC\Collaboration\Reference\RenderReferenceEventListener::register(Server::get(IEventDispatcher::class));
+	}
+
 	/**
 	 * register hooks for sharing
 	 */
diff --git a/lib/private/Collaboration/Reference/ReferenceManager.php b/lib/private/Collaboration/Reference/ReferenceManager.php
index a11d92fe2a9..1b00b9325ca 100644
--- a/lib/private/Collaboration/Reference/ReferenceManager.php
+++ b/lib/private/Collaboration/Reference/ReferenceManager.php
@@ -26,6 +26,7 @@ namespace OC\Collaboration\Reference;
 
 use OC\AppFramework\Bootstrap\Coordinator;
 use OC\Collaboration\Reference\File\FileReferenceProvider;
+use OCP\Collaboration\Reference\IDiscoverableReferenceProvider;
 use OCP\Collaboration\Reference\IReference;
 use OCP\Collaboration\Reference\IReferenceManager;
 use OCP\Collaboration\Reference\IReferenceProvider;
@@ -56,6 +57,12 @@ class ReferenceManager implements IReferenceManager {
 		$this->logger = $logger;
 	}
 
+	/**
+	 * Extract a list of URLs from a text
+	 *
+	 * @param string $text
+	 * @return string[]
+	 */
 	public function extractReferences(string $text): array {
 		preg_match_all(IURLGenerator::URL_REGEX, $text, $matches);
 		$references = $matches[0] ?? [];
@@ -64,6 +71,12 @@ class ReferenceManager implements IReferenceManager {
 		}, $references);
 	}
 
+	/**
+	 * Try to get a cached reference object from a reference string
+	 *
+	 * @param string $referenceId
+	 * @return IReference|null
+	 */
 	public function getReferenceFromCache(string $referenceId): ?IReference {
 		$matchedProvider = $this->getMatchedProvider($referenceId);
 
@@ -75,6 +88,12 @@ class ReferenceManager implements IReferenceManager {
 		return $this->getReferenceByCacheKey($cacheKey);
 	}
 
+	/**
+	 * Try to get a cached reference object from a full cache key
+	 *
+	 * @param string $cacheKey
+	 * @return IReference|null
+	 */
 	public function getReferenceByCacheKey(string $cacheKey): ?IReference {
 		$cached = $this->cache->get($cacheKey);
 		if ($cached) {
@@ -84,6 +103,13 @@ class ReferenceManager implements IReferenceManager {
 		return null;
 	}
 
+	/**
+	 * Get a reference object from a reference string with a matching provider
+	 * Use a cached reference if possible
+	 *
+	 * @param string $referenceId
+	 * @return IReference|null
+	 */
 	public function resolveReference(string $referenceId): ?IReference {
 		$matchedProvider = $this->getMatchedProvider($referenceId);
 
@@ -106,6 +132,13 @@ class ReferenceManager implements IReferenceManager {
 		return null;
 	}
 
+	/**
+	 * Try to match a reference string with all the registered providers
+	 * Fallback to the link reference provider (using OpenGraph)
+	 *
+	 * @param string $referenceId
+	 * @return IReferenceProvider|null the first matching provider
+	 */
 	private function getMatchedProvider(string $referenceId): ?IReferenceProvider {
 		$matchedProvider = null;
 		foreach ($this->getProviders() as $provider) {
@@ -122,6 +155,13 @@ class ReferenceManager implements IReferenceManager {
 		return $matchedProvider;
 	}
 
+	/**
+	 * Get a hashed full cache key from a key and prefix given by a provider
+	 *
+	 * @param IReferenceProvider $provider
+	 * @param string $referenceId
+	 * @return string
+	 */
 	private function getFullCacheKey(IReferenceProvider $provider, string $referenceId): string {
 		$cacheKey = $provider->getCacheKey($referenceId);
 		return md5($provider->getCachePrefix($referenceId)) . (
@@ -129,6 +169,13 @@ class ReferenceManager implements IReferenceManager {
 		);
 	}
 
+	/**
+	 * Remove a specific cache entry from its key+prefix
+	 *
+	 * @param string $cachePrefix
+	 * @param string|null $cacheKey
+	 * @return void
+	 */
 	public function invalidateCache(string $cachePrefix, ?string $cacheKey = null): void {
 		if ($cacheKey === null) {
 			$this->cache->clear(md5($cachePrefix));
@@ -167,4 +214,19 @@ class ReferenceManager implements IReferenceManager {
 
 		return $this->providers;
 	}
+
+	/**
+	 * Get information on discoverable reference providers (id, title, icon and order)
+	 * If the provider is searchable, also get the list of supported unified search providers
+	 *
+	 * @return IDiscoverableReferenceProvider[]
+	 */
+	public function getDiscoverableProviders(): array {
+		// preserve 0 based index to avoid returning an object in data responses
+		return array_values(
+			array_filter($this->getProviders(), static function (IReferenceProvider $provider) {
+				return $provider instanceof IDiscoverableReferenceProvider;
+			})
+		);
+	}
 }
diff --git a/lib/private/Collaboration/Reference/RenderReferenceEventListener.php b/lib/private/Collaboration/Reference/RenderReferenceEventListener.php
new file mode 100644
index 00000000000..172dca3d7f2
--- /dev/null
+++ b/lib/private/Collaboration/Reference/RenderReferenceEventListener.php
@@ -0,0 +1,62 @@
+<?php
+
+declare(strict_types=1);
+/**
+ * @copyright Copyright (c) 2022 Julien Veyssier <eneiluj@posteo.net>
+ *
+ * @author Julien Veyssier <eneiluj@posteo.net>
+ *
+ * @license GNU AGPL version 3 or any later version
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+namespace OC\Collaboration\Reference;
+
+use OCP\Collaboration\Reference\IDiscoverableReferenceProvider;
+use OCP\Collaboration\Reference\IReferenceManager;
+use OCP\Collaboration\Reference\RenderReferenceEvent;
+use OCP\EventDispatcher\Event;
+use OCP\EventDispatcher\IEventDispatcher;
+use OCP\EventDispatcher\IEventListener;
+use OCP\IInitialStateService;
+
+class RenderReferenceEventListener implements IEventListener {
+	private IReferenceManager $manager;
+	private IInitialStateService $initialStateService;
+
+	public function __construct(IReferenceManager $manager, IInitialStateService $initialStateService) {
+		$this->manager = $manager;
+		$this->initialStateService = $initialStateService;
+	}
+
+	public static function register(IEventDispatcher $eventDispatcher): void {
+		$eventDispatcher->addServiceListener(RenderReferenceEvent::class, RenderReferenceEventListener::class);
+	}
+
+	/**
+	 * @inheritDoc
+	 */
+	public function handle(Event $event): void {
+		if (!($event instanceof RenderReferenceEvent)) {
+			return;
+		}
+
+		$providers = $this->manager->getDiscoverableProviders();
+		$jsonProviders = array_map(static function (IDiscoverableReferenceProvider $provider) {
+			return $provider->jsonSerialize();
+		}, $providers);
+		$this->initialStateService->provideInitialState('core', 'reference-provider-list', $jsonProviders);
+	}
+}
diff --git a/lib/public/Collaboration/Reference/ADiscoverableReferenceProvider.php b/lib/public/Collaboration/Reference/ADiscoverableReferenceProvider.php
new file mode 100644
index 00000000000..56b97957a02
--- /dev/null
+++ b/lib/public/Collaboration/Reference/ADiscoverableReferenceProvider.php
@@ -0,0 +1,47 @@
+<?php
+
+declare(strict_types=1);
+/**
+ * @copyright Copyright (c) 2022 Julien Veyssier <eneiluj@posteo.net>
+ *
+ * @author Julien Veyssier <eneiluj@posteo.net>
+ *
+ * @license GNU AGPL version 3 or any later version
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+namespace OCP\Collaboration\Reference;
+
+/**
+ * @since 26.0.0
+ */
+abstract class ADiscoverableReferenceProvider implements IDiscoverableReferenceProvider {
+
+	/**
+	 * @inheritDoc
+	 */
+	public function jsonSerialize(): array {
+		$json = [
+			'id' => $this->getId(),
+			'title' => $this->getTitle(),
+			'icon_url' => $this->getIconUrl(),
+			'order' => $this->getOrder(),
+		];
+		if ($this instanceof ISearchableReferenceProvider) {
+			$json['search_providers_ids'] = $this->getSupportedSearchProviderIds();
+		}
+		return $json;
+	}
+}
diff --git a/lib/public/Collaboration/Reference/IDiscoverableReferenceProvider.php b/lib/public/Collaboration/Reference/IDiscoverableReferenceProvider.php
new file mode 100644
index 00000000000..847e03c602e
--- /dev/null
+++ b/lib/public/Collaboration/Reference/IDiscoverableReferenceProvider.php
@@ -0,0 +1,60 @@
+<?php
+
+declare(strict_types=1);
+/**
+ * @copyright Copyright (c) 2022 Julien Veyssier <eneiluj@posteo.net>
+ *
+ * @author Julien Veyssier <eneiluj@posteo.net>
+ *
+ * @license GNU AGPL version 3 or any later version
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+namespace OCP\Collaboration\Reference;
+
+/**
+ * @since 26.0.0
+ */
+interface IDiscoverableReferenceProvider extends IReferenceProvider {
+	/**
+	 * @return string Unique id that identifies the reference provider
+	 * @since 26.0.0
+	 */
+	public function getId(): string;
+
+	/**
+	 * @return string User facing title of the widget
+	 * @since 26.0.0
+	 */
+	public function getTitle(): string;
+
+	/**
+	 * @return int Initial order for reference provider sorting
+	 * @since 26.0.0
+	 */
+	public function getOrder(): int;
+
+	/**
+	 * @return string url to an icon that can be displayed next to the reference provider title
+	 * @since 26.0.0
+	 */
+	public function getIconUrl(): string;
+
+	/**
+	 * @return array representation of the provider
+	 * @since 26.0.0
+	 */
+	public function jsonSerialize(): array;
+}
diff --git a/lib/public/Collaboration/Reference/IReferenceManager.php b/lib/public/Collaboration/Reference/IReferenceManager.php
index 487e243c7ed..31977be4d74 100644
--- a/lib/public/Collaboration/Reference/IReferenceManager.php
+++ b/lib/public/Collaboration/Reference/IReferenceManager.php
@@ -67,4 +67,12 @@ interface IReferenceManager {
 	 * @since 25.0.0
 	 */
 	public function invalidateCache(string $cachePrefix, ?string $cacheKey = null): void;
+
+	/**
+	 * Get list of providers that implement IDiscoverableReferenceProvider
+	 *
+	 * @return IDiscoverableReferenceProvider[]
+	 * @since 26.0.0
+	 */
+	public function getDiscoverableProviders(): array;
 }
diff --git a/lib/public/Collaboration/Reference/ISearchableReferenceProvider.php b/lib/public/Collaboration/Reference/ISearchableReferenceProvider.php
new file mode 100644
index 00000000000..b863de468a8
--- /dev/null
+++ b/lib/public/Collaboration/Reference/ISearchableReferenceProvider.php
@@ -0,0 +1,36 @@
+<?php
+
+declare(strict_types=1);
+/**
+ * @copyright Copyright (c) 2022 Julien Veyssier <eneiluj@posteo.net>
+ *
+ * @author Julien Veyssier <eneiluj@posteo.net>
+ *
+ * @license GNU AGPL version 3 or any later version
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+namespace OCP\Collaboration\Reference;
+
+/**
+ * @since 26.0.0
+ */
+interface ISearchableReferenceProvider extends IDiscoverableReferenceProvider {
+	/**
+	 * @return string[] list of search provider IDs that can be used by the vue-richtext picker
+	 * @since 26.0.0
+	 */
+	public function getSupportedSearchProviderIds(): array;
+}