1 files changed, 157 insertions, 0 deletions
diff --git a/lib/private/Updater/ChangesCheck.php b/lib/private/Updater/ChangesCheck.php
new file mode 100644
index 00000000000..095f63db879
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+++ b/lib/private/Updater/ChangesCheck.php
@@ -0,0 +1,157 @@
+<?php
+declare(strict_types=1);
+/**
+ * @copyright Copyright (c) 2018 Arthur Schiwon <blizzz@arthur-schiwon.de>
+ *
+ * @author Arthur Schiwon <blizzz@arthur-schiwon.de>
+ *
+ * @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\Updater;
+
+use OCP\AppFramework\Db\DoesNotExistException;
+use OCP\Http\Client\IClientService;
+use OCP\Http\Client\IResponse;
+use OCP\ILogger;
+
+class ChangesCheck {
+	/** @var IClientService */
+	protected $clientService;
+	/** @var ChangesMapper */
+	private $mapper;
+	/** @var ILogger */
+	private $logger;
+
+	const RESPONSE_NO_CONTENT = 0;
+	const RESPONSE_USE_CACHE = 1;
+	const RESPONSE_HAS_CONTENT = 2;
+
+	public function __construct(IClientService $clientService, ChangesMapper $mapper, ILogger $logger) {
+		$this->clientService = $clientService;
+		$this->mapper = $mapper;
+		$this->logger = $logger;
+	}
+
+	/**
+	 * @throws \Exception
+	 */
+	public function check(string $uri, string $version): array {
+		try {
+			$version = $this->normalizeVersion($version);
+			$changesInfo = $this->mapper->getChanges($version);
+			if($changesInfo->getLastCheck() + 1800 > time()) {
+				return json_decode($changesInfo->getData(), true);
+			}
+		} catch (DoesNotExistException $e) {
+			$changesInfo = new ChangesResult();
+		}
+
+		$response = $this->queryChangesServer($uri, $changesInfo);
+
+		switch($this->evaluateResponse($response)) {
+			case self::RESPONSE_NO_CONTENT:
+				return [];
+			case self::RESPONSE_USE_CACHE:
+				return json_decode($changesInfo->getData(), true);
+			case self::RESPONSE_HAS_CONTENT:
+			default:
+				$data = $this->extractData($response->getBody());
+				$changesInfo->setData(json_encode($data));
+				$changesInfo->setEtag($response->getHeader('Etag'));
+				$this->cacheResult($changesInfo, $version);
+
+				return $data;
+		}
+	}
+
+	protected function evaluateResponse(IResponse $response): int {
+		if($response->getStatusCode() === 304) {
+			return self::RESPONSE_USE_CACHE;
+		} else if($response->getStatusCode() === 404) {
+			return self::RESPONSE_NO_CONTENT;
+		} else if($response->getStatusCode() === 200) {
+			return self::RESPONSE_HAS_CONTENT;
+		}
+		$this->logger->debug('Unexpected return code {code} from changelog server', [
+			'app' => 'core',
+			'code' => $response->getStatusCode(),
+		]);
+		return self::RESPONSE_NO_CONTENT;
+	}
+
+	protected function cacheResult(ChangesResult $entry, string $version) {
+		if($entry->getVersion() === $version) {
+			$this->mapper->update($entry);
+		} else {
+			$entry->setVersion($version);
+			$this->mapper->insert($entry);
+		}
+	}
+
+	/**
+	 * @throws \Exception
+	 */
+	protected function queryChangesServer(string $uri, ChangesResult $entry): IResponse {
+		$headers = [];
+		if($entry->getEtag() !== '') {
+			$headers['If-None-Match'] = [$entry->getEtag()];
+		}
+
+		$entry->setLastCheck(time());
+		$client = $this->clientService->newClient();
+		return $client->get($uri, [
+			'headers' => $headers,
+		]);
+	}
+
+	protected function extractData($body):array {
+		$data = [];
+		if ($body) {
+			$loadEntities = libxml_disable_entity_loader(true);
+			$xml = @simplexml_load_string($body);
+			libxml_disable_entity_loader($loadEntities);
+			if ($xml !== false) {
+				$data['changelogURL'] = (string)$xml->changelog['href'];
+				$data['whatsNew'] = [];
+				foreach($xml->whatsNew as $infoSet) {
+					$data['whatsNew'][(string)$infoSet['lang']] = [
+						'regular' => (array)$infoSet->regular->item,
+						'admin' => (array)$infoSet->admin->item,
+					];
+				}
+			} else {
+				libxml_clear_errors();
+			}
+		}
+		return $data;
+	}
+
+	/**
+	 * returns a x.y.z form of the provided version. Extra numbers will be
+	 * omitted, missing ones added as zeros.
+	 */
+	protected function normalizeVersion(string $version): string {
+		$versionNumbers = array_slice(explode('.', $version), 0, 3);
+		$versionNumbers[0] = $versionNumbers[0] ?: '0'; // deal with empty input
+		while(count($versionNumbers) < 3) {
+			// changelog server expects x.y.z, pad 0 if it is too short
+			$versionNumbers[] = 0;
+		}
+		return implode('.', $versionNumbers);
+	}
+}