3 files changed, 494 insertions, 0 deletions
diff --git a/lib/private/OCM/Model/OCMProvider.php b/lib/private/OCM/Model/OCMProvider.php
new file mode 100644
index 00000000000..084d4f8479d
--- /dev/null
+++ b/lib/private/OCM/Model/OCMProvider.php
@@ -0,0 +1,234 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * @copyright 2023, Maxence Lange <maxence@artificial-owl.com>
+ *
+ * @author Maxence Lange <maxence@artificial-owl.com>
+ *
+ * @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\OCM\Model;
+
+use OCP\EventDispatcher\IEventDispatcher;
+use OCP\OCM\Events\ResourceTypeRegisterEvent;
+use OCP\OCM\Exceptions\OCMArgumentException;
+use OCP\OCM\Exceptions\OCMProviderException;
+use OCP\OCM\IOCMProvider;
+use OCP\OCM\IOCMResource;
+
+/**
+ * @since 28.0.0
+ */
+class OCMProvider implements IOCMProvider {
+	private bool $enabled = false;
+	private string $apiVersion = '';
+	private string $endPoint = '';
+	/** @var IOCMResource[] */
+	private array $resourceTypes = [];
+
+	private bool $emittedEvent = false;
+
+	public function __construct(
+		protected IEventDispatcher $dispatcher,
+	) {
+	}
+
+	/**
+	 * @param bool $enabled
+	 *
+	 * @return $this
+	 */
+	public function setEnabled(bool $enabled): static {
+		$this->enabled = $enabled;
+
+		return $this;
+	}
+
+	/**
+	 * @return bool
+	 */
+	public function isEnabled(): bool {
+		return $this->enabled;
+	}
+
+	/**
+	 * @param string $apiVersion
+	 *
+	 * @return $this
+	 */
+	public function setApiVersion(string $apiVersion): static {
+		$this->apiVersion = $apiVersion;
+
+		return $this;
+	}
+
+	/**
+	 * @return string
+	 */
+	public function getApiVersion(): string {
+		return $this->apiVersion;
+	}
+
+	/**
+	 * @param string $endPoint
+	 *
+	 * @return $this
+	 */
+	public function setEndPoint(string $endPoint): static {
+		$this->endPoint = $endPoint;
+
+		return $this;
+	}
+
+	/**
+	 * @return string
+	 */
+	public function getEndPoint(): string {
+		return $this->endPoint;
+	}
+
+	/**
+	 * create a new resource to later add it with {@see IOCMProvider::addResourceType()}
+	 * @return IOCMResource
+	 */
+	public function createNewResourceType(): IOCMResource {
+		return new OCMResource();
+	}
+
+	/**
+	 * @param IOCMResource $resource
+	 *
+	 * @return $this
+	 */
+	public function addResourceType(IOCMResource $resource): static {
+		$this->resourceTypes[] = $resource;
+
+		return $this;
+	}
+
+	/**
+	 * @param IOCMResource[] $resourceTypes
+	 *
+	 * @return $this
+	 */
+	public function setResourceTypes(array $resourceTypes): static {
+		$this->resourceTypes = $resourceTypes;
+
+		return $this;
+	}
+
+	/**
+	 * @return IOCMResource[]
+	 */
+	public function getResourceTypes(): array {
+		if (!$this->emittedEvent) {
+			$this->emittedEvent = true;
+			$event = new ResourceTypeRegisterEvent($this);
+			$this->dispatcher->dispatchTyped($event);
+		}
+
+		return $this->resourceTypes;
+	}
+
+	/**
+	 * @param string $resourceName
+	 * @param string $protocol
+	 *
+	 * @return string
+	 * @throws OCMArgumentException
+	 */
+	public function extractProtocolEntry(string $resourceName, string $protocol): string {
+		foreach ($this->getResourceTypes() as $resource) {
+			if ($resource->getName() === $resourceName) {
+				$entry = $resource->getProtocols()[$protocol] ?? null;
+				if (is_null($entry)) {
+					throw new OCMArgumentException('protocol not found');
+				}
+
+				return (string)$entry;
+			}
+		}
+
+		throw new OCMArgumentException('resource not found');
+	}
+
+	/**
+	 * import data from an array
+	 *
+	 * @param array $data
+	 *
+	 * @return $this
+	 * @throws OCMProviderException in case a descent provider cannot be generated from data
+	 * @see self::jsonSerialize()
+	 */
+	public function import(array $data): static {
+		$this->setEnabled(is_bool($data['enabled'] ?? '') ? $data['enabled'] : false)
+			 ->setApiVersion((string)($data['apiVersion'] ?? ''))
+			 ->setEndPoint($data['endPoint'] ?? '');
+
+		$resources = [];
+		foreach (($data['resourceTypes'] ?? []) as $resourceData) {
+			$resource = new OCMResource();
+			$resources[] = $resource->import($resourceData);
+		}
+		$this->setResourceTypes($resources);
+
+		if (!$this->looksValid()) {
+			throw new OCMProviderException('remote provider does not look valid');
+		}
+
+		return $this;
+	}
+
+
+	/**
+	 * @return bool
+	 */
+	private function looksValid(): bool {
+		return ($this->getApiVersion() !== '' && $this->getEndPoint() !== '');
+	}
+
+
+	/**
+	 * @return array{
+	 *     enabled: bool,
+	 *     apiVersion: string,
+	 *     endPoint: string,
+	 *     resourceTypes: array{
+	 *              name: string,
+	 *              shareTypes: string[],
+	 *              protocols: array<string, string>
+	 *            }[]
+	 *   }
+	 */
+	public function jsonSerialize(): array {
+		$resourceTypes = [];
+		foreach ($this->getResourceTypes() as $res) {
+			$resourceTypes[] = $res->jsonSerialize();
+		}
+
+		return [
+			'enabled' => $this->isEnabled(),
+			'apiVersion' => $this->getApiVersion(),
+			'endPoint' => $this->getEndPoint(),
+			'resourceTypes' => $resourceTypes
+		];
+	}
+}
diff --git a/lib/private/OCM/Model/OCMResource.php b/lib/private/OCM/Model/OCMResource.php
new file mode 100644
index 00000000000..c4a91f2eabf
--- /dev/null
+++ b/lib/private/OCM/Model/OCMResource.php
@@ -0,0 +1,123 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * @copyright 2023, Maxence Lange <maxence@artificial-owl.com>
+ *
+ * @author Maxence Lange <maxence@artificial-owl.com>
+ *
+ * @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\OCM\Model;
+
+use OCP\OCM\IOCMResource;
+
+/**
+ * @since 28.0.0
+ */
+class OCMResource implements IOCMResource {
+	private string $name = '';
+	/** @var string[] */
+	private array $shareTypes = [];
+	/** @var array<string, string> */
+	private array $protocols = [];
+
+	/**
+	 * @param string $name
+	 *
+	 * @return $this
+	 */
+	public function setName(string $name): static {
+		$this->name = $name;
+
+		return $this;
+	}
+
+	/**
+	 * @return string
+	 */
+	public function getName(): string {
+		return $this->name;
+	}
+
+	/**
+	 * @param string[] $shareTypes
+	 *
+	 * @return $this
+	 */
+	public function setShareTypes(array $shareTypes): static {
+		$this->shareTypes = $shareTypes;
+
+		return $this;
+	}
+
+	/**
+	 * @return string[]
+	 */
+	public function getShareTypes(): array {
+		return $this->shareTypes;
+	}
+
+	/**
+	 * @param array<string, string> $protocols
+	 *
+	 * @return $this
+	 */
+	public function setProtocols(array $protocols): static {
+		$this->protocols = $protocols;
+
+		return $this;
+	}
+
+	/**
+	 * @return array<string, string>
+	 */
+	public function getProtocols(): array {
+		return $this->protocols;
+	}
+
+	/**
+	 * import data from an array
+	 *
+	 * @param array $data
+	 *
+	 * @return $this
+	 * @see self::jsonSerialize()
+	 */
+	public function import(array $data): static {
+		return $this->setName((string)($data['name'] ?? ''))
+					->setShareTypes($data['shareTypes'] ?? [])
+					->setProtocols($data['protocols'] ?? []);
+	}
+
+	/**
+	 * @return array{
+	 *     name: string,
+	 *     shareTypes: string[],
+	 *     protocols: array<string, string>
+	 * }
+	 */
+	public function jsonSerialize(): array {
+		return [
+			'name' => $this->getName(),
+			'shareTypes' => $this->getShareTypes(),
+			'protocols' => $this->getProtocols()
+		];
+	}
+}
diff --git a/lib/private/OCM/OCMDiscoveryService.php b/lib/private/OCM/OCMDiscoveryService.php
new file mode 100644
index 00000000000..ac9bf2a3965
--- /dev/null
+++ b/lib/private/OCM/OCMDiscoveryService.php
@@ -0,0 +1,137 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * @copyright 2023, Maxence Lange <maxence@artificial-owl.com>
+ *
+ * @author Maxence Lange <maxence@artificial-owl.com>
+ *
+ * @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\OCM;
+
+use JsonException;
+use OCP\AppFramework\Http;
+use OCP\Http\Client\IClientService;
+use OCP\ICache;
+use OCP\ICacheFactory;
+use OCP\IConfig;
+use OCP\OCM\Exceptions\OCMProviderException;
+use OCP\OCM\IOCMDiscoveryService;
+use OCP\OCM\IOCMProvider;
+use Psr\Log\LoggerInterface;
+
+/**
+ * @since 28.0.0
+ */
+class OCMDiscoveryService implements IOCMDiscoveryService {
+	private ICache $cache;
+	private array $supportedAPIVersion =
+		[
+			'1.0-proposal1',
+			'1.0',
+			'1.1'
+		];
+
+	public function __construct(
+		ICacheFactory $cacheFactory,
+		private IClientService $clientService,
+		private IConfig $config,
+		private IOCMProvider $provider,
+		private LoggerInterface $logger,
+	) {
+		$this->cache = $cacheFactory->createDistributed('ocm-discovery');
+	}
+
+
+	/**
+	 * @param string $remote
+	 * @param bool $skipCache
+	 *
+	 * @return IOCMProvider
+	 * @throws OCMProviderException
+	 */
+	public function discover(string $remote, bool $skipCache = false): IOCMProvider {
+		$remote = rtrim($remote, '/');
+
+		if (!$skipCache) {
+			try {
+				$this->provider->import(json_decode($this->cache->get($remote) ?? '', true, 8, JSON_THROW_ON_ERROR) ?? []);
+				if ($this->supportedAPIVersion($this->provider->getApiVersion())) {
+					return $this->provider; // if cache looks valid, we use it
+				}
+			} catch (JsonException|OCMProviderException $e) {
+				// we ignore cache on issues
+			}
+		}
+
+		$client = $this->clientService->newClient();
+		try {
+			$response = $client->get(
+				$remote . '/ocm-provider/',
+				[
+					'timeout' => 10,
+					'verify' => !$this->config->getSystemValueBool('sharing.federation.allowSelfSignedCertificates'),
+					'connect_timeout' => 10,
+				]
+			);
+
+			if ($response->getStatusCode() === Http::STATUS_OK) {
+				$body = $response->getBody();
+				// update provider with data returned by the request
+				$this->provider->import(json_decode($body, true, 8, JSON_THROW_ON_ERROR) ?? []);
+				$this->cache->set($remote, $body, 60 * 60 * 24);
+			}
+		} catch (JsonException|OCMProviderException $e) {
+			throw new OCMProviderException('data returned by remote seems invalid - ' . ($body ?? ''));
+		} catch (\Exception $e) {
+			$this->logger->warning('error while discovering ocm provider', [
+				'exception' => $e,
+				'remote' => $remote
+			]);
+			throw new OCMProviderException('error while requesting remote ocm provider');
+		}
+
+		if (!$this->supportedAPIVersion($this->provider->getApiVersion())) {
+			throw new OCMProviderException('API version not supported');
+		}
+
+		return $this->provider;
+	}
+
+	/**
+	 * Check the version from remote is supported.
+	 * The minor version of the API will be ignored:
+	 *    1.0.1 is identified as 1.0
+	 *
+	 * @param string $version
+	 *
+	 * @return bool
+	 */
+	private function supportedAPIVersion(string $version): bool {
+		$dot1 = strpos($version, '.');
+		$dot2 = strpos($version, '.', $dot1 + 1);
+
+		if ($dot2 > 0) {
+			$version = substr($version, 0, $dot2);
+		}
+
+		return (in_array($version, $this->supportedAPIVersion));
+	}
+}