From 8dc989f8979a76290ece079b8dab759c227da867 Mon Sep 17 00:00:00 2001
From: Jonathan Treffler <mail@jonathan-treffler.de>
Date: Fri, 3 May 2024 18:18:33 +0200
Subject: [PATCH] started implementing subscription management

---
 lib/Dav/SubscriptionManagementPlugin.php | 142 +++++++++++++++++++++++
 lib/Listener/SabrePluginAddListener.php  |   3 +
 2 files changed, 145 insertions(+)
 create mode 100644 lib/Dav/SubscriptionManagementPlugin.php

diff --git a/lib/Dav/SubscriptionManagementPlugin.php b/lib/Dav/SubscriptionManagementPlugin.php
new file mode 100644
index 0000000..9786167
--- /dev/null
+++ b/lib/Dav/SubscriptionManagementPlugin.php
@@ -0,0 +1,142 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * @copyright 2024 Jonathan Treffler <mail@jonathan-treffler.de>
+ *
+ * @author Jonathan Treffler <mail@jonathan-treffler.de>
+ * @author Thomas Müller <thomas.mueller@tmit.eu>
+ *
+ * @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 OCA\DavPush\Dav;
+
+use OCP\IUserSession;
+
+use OCP\AppFramework\Http;
+
+use Sabre\DAV\Server;
+use Sabre\DAV\ServerPlugin;
+use Sabre\HTTP\RequestInterface;
+use Sabre\HTTP\ResponseInterface;
+
+class SubscriptionManagementPlugin extends ServerPlugin {
+
+	public const PUSH_PREFIX = '{DAV:Push}';
+	public const PUSH_REGISTER = self::PUSH_PREFIX . "push-register";
+	public const PUSH_SUBSCRIPTION = self::PUSH_PREFIX . "subscription";
+	public const PUSH_EXPIRES = self::PUSH_PREFIX . "expires";
+
+	/**
+	 * Reference to SabreDAV server object.
+	 *
+	 * @var \Sabre\DAV\Server
+	 */
+	protected $server;
+
+	public function __construct(
+		private IUserSession $userSession,
+	) {
+	}
+
+	public function initialize(Server $server): void {
+		$this->server = $server;
+
+		$this->server->on('method:POST', [$this, 'httpPost']);
+	}
+
+	public function httpPost(RequestInterface $request, ResponseInterface $response) {
+		// Only handle xml
+		$contentType = (string) $request->getHeader('Content-Type');
+		if (!(str_contains($contentType, 'application/xml') || str_contains($contentType, 'text/xml'))) {
+			return;
+		}
+
+		$requestBody = $request->getBodyAsString();
+
+		// If this request handler could not deal with this POST request, it
+		// will return 'null' and other plugins get a chance to handle the
+		// request.
+		//
+		// However, we already requested the full body. This is a problem,
+		// because a body can only be read once. This is why we preemptively
+		// re-populated the request body with the existing data.
+		$request->setBody($requestBody);
+
+		$parameters = $this->server->xml->parse($requestBody, $request->getUrl(), $documentType);
+
+		if($documentType == self::PUSH_REGISTER) {
+			$errors = [];
+
+			$subscriptionParameterIncluded = False;
+
+			$subscriptionType = "";
+			$subscriptionOptions = [];
+			$subscriptionExpires = False;
+
+			foreach($parameters as $parameter) {
+				if($parameter["name"] == self::PUSH_SUBSCRIPTION && !$subscriptionParameterIncluded) {
+					$subscriptionParameterIncluded = True;
+					
+					if(sizeof($parameter["value"]) == 1) {
+						$subscriptionType = $parameter["value"][0]["name"];
+						$subscriptionOptions = $parameter["value"][0]["value"];
+					} else {
+						$errors[] = "only one subscription allowed";
+					}
+				} elif($parameter["name"] == self::PUSH_EXPIRES && !$subscriptionExpires) {
+					$subscriptionExpires = $parameter["value"];
+				}
+			}
+
+			if(!$subscriptionParameterIncluded) {
+				$errors[] = "no subscription included";
+			}
+
+			if(sizeof($errors) == 0) {
+				$response->setStatus(Http::STATUS_CREATED);
+
+				//$response->setBody($subscriptionType);
+				//$response->setBody(json_encode($parameters));
+
+				// pass data to applicable transport class
+			} else {
+				$response->setStatus(Http::STATUS_BAD_REQUEST);
+
+				$errorsXML = [];
+
+				foreach($errors as $error) {
+					$errorsXML[] = [
+						"name" => "error",
+						"value" => $error
+					];
+				}
+
+				$xml = $this->server->xml->write(
+					'{DAV:}error',
+					$errorsXML
+				);
+
+				$response->setBody($xml);
+			}
+
+			return false;
+		}
+	}
+}
\ No newline at end of file
diff --git a/lib/Listener/SabrePluginAddListener.php b/lib/Listener/SabrePluginAddListener.php
index 4c74c87..6fb9bd0 100644
--- a/lib/Listener/SabrePluginAddListener.php
+++ b/lib/Listener/SabrePluginAddListener.php
@@ -28,6 +28,7 @@ namespace OCA\DavPush\Listener;
 
 use OCA\DAV\Events\SabrePluginAddEvent;
 use OCA\DavPush\Dav\ServiceDetectionPlugin;
+use OCA\DavPush\Dav\SubscriptionManagementPlugin;
 
 use OCP\EventDispatcher\Event;
 use OCP\EventDispatcher\IEventListener;
@@ -40,8 +41,10 @@ class SabrePluginAddListener implements IEventListener {
 	public function handle(Event $event): void {
 		if ($event instanceof SabrePluginAddEvent) {
 			$serviceDetectionPlugin = $this->container->get(ServiceDetectionPlugin::class);
+			$subscriptionManagementPlugin = $this->container->get(SubscriptionManagementPlugin::class);
 
 			$event->getServer()->addPlugin($serviceDetectionPlugin);
+			$event->getServer()->addPlugin($subscriptionManagementPlugin);
 		}
 	}
 }
\ No newline at end of file