1 files changed, 158 insertions, 0 deletions
diff --git a/lib/private/Updater/ChangesCheck.php b/lib/private/Updater/ChangesCheck.php
new file mode 100644
index 00000000000..e88969f62a8
--- /dev/null
+++ b/lib/private/Updater/ChangesCheck.php
@@ -0,0 +1,158 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * SPDX-FileCopyrightText: 2018 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+namespace OC\Updater;
+
+use OCP\AppFramework\Db\DoesNotExistException;
+use OCP\Http\Client\IClientService;
+use OCP\Http\Client\IResponse;
+use Psr\Log\LoggerInterface;
+
+class ChangesCheck {
+	/** @var IClientService */
+	protected $clientService;
+	/** @var ChangesMapper */
+	private $mapper;
+	private LoggerInterface $logger;
+
+	public const RESPONSE_NO_CONTENT = 0;
+	public const RESPONSE_USE_CACHE = 1;
+	public const RESPONSE_HAS_CONTENT = 2;
+
+	public function __construct(IClientService $clientService, ChangesMapper $mapper, LoggerInterface $logger) {
+		$this->clientService = $clientService;
+		$this->mapper = $mapper;
+		$this->logger = $logger;
+	}
+
+	/**
+	 * @throws DoesNotExistException
+	 * @return array{changelogURL: string, whatsNew: array<string, array{admin: list<string>, regular: list<string>}>}
+	 */
+	public function getChangesForVersion(string $version): array {
+		$version = $this->normalizeVersion($version);
+		$changesInfo = $this->mapper->getChanges($version);
+		$changesData = json_decode($changesInfo->getData(), true);
+		if (empty($changesData)) {
+			throw new DoesNotExistException('Unable to decode changes info');
+		}
+		return $changesData;
+	}
+
+	/**
+	 * @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 Changes();
+		}
+
+		$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;
+		} elseif ($response->getStatusCode() === 404) {
+			return self::RESPONSE_NO_CONTENT;
+		} elseif ($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(Changes $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, Changes $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) {
+			if (\LIBXML_VERSION < 20900) {
+				$loadEntities = libxml_disable_entity_loader(true);
+				$xml = @simplexml_load_string($body);
+				libxml_disable_entity_loader($loadEntities);
+			} else {
+				$xml = @simplexml_load_string($body);
+			}
+			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.
+	 */
+	public 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);
+	}
+}