1 files changed, 114 insertions, 0 deletions
diff --git a/apps/updatenotification/lib/Manager.php b/apps/updatenotification/lib/Manager.php
new file mode 100644
index 00000000000..ebc1c83a9b4
--- /dev/null
+++ b/apps/updatenotification/lib/Manager.php
@@ -0,0 +1,114 @@
+<?php
+
+declare(strict_types=1);
+/**
+ * SPDX-FileCopyrightText: 2024 Nextcloud GmbH and Nextcloud contributors
+ * SPDX-License-Identifier: AGPL-3.0-or-later
+ */
+
+namespace OCA\UpdateNotification;
+
+use OCP\App\IAppManager;
+use OCP\IUser;
+use OCP\IUserSession;
+use OCP\L10N\IFactory;
+use Psr\Log\LoggerInterface;
+
+class Manager {
+
+	private ?IUser $currentUser;
+
+	public function __construct(
+		IUserSession $currentSession,
+		private IAppManager $appManager,
+		private IFactory $l10NFactory,
+		private LoggerInterface $logger,
+	) {
+		$this->currentUser = $currentSession->getUser();
+	}
+
+	/**
+	 * Get the changelog entry for the given appId
+	 * @param string $appId The app for which to query the entry
+	 * @param string $version The version for which to query the changelog entry
+	 * @param ?string $languageCode The language in which to query the changelog (defaults to current user language and fallsback to English)
+	 * @return string|null Either the changelog entry or null if no changelog is found
+	 */
+	public function getChangelog(string $appId, string $version, ?string $languageCode = null): ?string {
+		if ($languageCode === null) {
+			$languageCode = $this->l10NFactory->getUserLanguage($this->currentUser);
+		}
+
+		$path = $this->getChangelogFile($appId, $languageCode);
+		if ($path === null) {
+			$this->logger->debug('No changelog file found for app ' . $appId . ' and language code ' . $languageCode);
+			return null;
+		}
+
+		$changes = $this->retrieveChangelogEntry($path, $version);
+		return $changes;
+	}
+
+	/**
+	 * Get the changelog file in the requested language or fallback to English
+	 * @param string $appId The app to load the changelog for
+	 * @param string $languageCode The language code to search
+	 * @return string|null Either the file path or null if not found
+	 */
+	public function getChangelogFile(string $appId, string $languageCode): ?string {
+		try {
+			$appPath = $this->appManager->getAppPath($appId);
+			$files = ["CHANGELOG.$languageCode.md", 'CHANGELOG.en.md'];
+			foreach ($files as $file) {
+				$path = $appPath . '/' . $file;
+				if (is_file($path)) {
+					return $path;
+				}
+			}
+		} catch (\Throwable $e) {
+			// ignore and return null below
+		}
+		return null;
+	}
+
+	/**
+	 * Retrieve a log entry from the changelog
+	 * @param string $path The path to the changelog file
+	 * @param string $version The version to query (make sure to only pass in "{major}.{minor}(.{patch}" format)
+	 */
+	protected function retrieveChangelogEntry(string $path, string $version): ?string {
+		$matches = [];
+		$content = file_get_contents($path);
+		if ($content === false) {
+			$this->logger->debug('Could not open changelog file', ['file-path' => $path]);
+			return null;
+		}
+
+		$result = preg_match_all('/^## (?:\[)?(?:v)?(\d+\.\d+(\.\d+)?)/m', $content, $matches, PREG_OFFSET_CAPTURE);
+		if ($result === false || $result === 0) {
+			$this->logger->debug('No entries in changelog found', ['file_path' => $path]);
+			return null;
+		}
+
+		// Get the key of the match that equals the requested version
+		$index = array_key_first(
+			// Get the array containing the match that equals the requested version, keys are preserved so: [1 => '1.2.4']
+			array_filter(
+				// This is the array of the versions found, like ['1.2.3', '1.2.4']
+				$matches[1],
+				// Callback to filter only version that matches the requested version
+				fn (array $match) => version_compare($match[0], $version, '=='),
+			)
+		);
+
+		if ($index === null) {
+			$this->logger->debug('No changelog entry for version ' . $version . ' found', ['file_path' => $path]);
+			return null;
+		}
+
+		$offsetChangelogEntry = $matches[0][$index][1];
+		// Length of the changelog entry (offset of next match - own offset) or null if the whole rest should be considered
+		$lengthChangelogEntry = $index < ($result - 1) ? ($matches[0][$index + 1][1] - $offsetChangelogEntry) : null;
+		return substr($content, $offsetChangelogEntry, $lengthChangelogEntry);
+	}
+}