1 files changed, 97 insertions, 0 deletions
diff --git a/lib/private/App/CompareVersion.php b/lib/private/App/CompareVersion.php
new file mode 100644
index 00000000000..ee25a8b9460
--- /dev/null
+++ b/lib/private/App/CompareVersion.php
@@ -0,0 +1,97 @@
+<?php
+
+/**
+ * @copyright 2018 Christoph Wurst <christoph@winzerhof-wurst.at>
+ *
+ * @author 2018 Christoph Wurst <christoph@winzerhof-wurst.at>
+ *
+ * @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\App;
+
+use InvalidArgumentException;
+
+class CompareVersion {
+
+	const REGEX_MAJOR = '/^\d+$/';
+	const REGEX_MAJOR_MINOR = '/^\d+.\d+$/';
+	const REGEX_MAJOR_MINOR_PATCH = '/^\d+.\d+.\d+$/';
+	const REGEX_SERVER = '/^\d+.\d+.\d+(.\d+)?$/';
+
+	/**
+	 * Checks if the given server version fulfills the given (app) version requirements.
+	 *
+	 * Version requirements can be 'major.minor.patch', 'major.minor' or just 'major',
+	 * so '13.0.1', '13.0' and '13' are valid.
+	 *
+	 * @param string $actual version as major.minor.patch notation
+	 * @param string $required version where major is requried and minor and patch are optional
+	 * @param string $comparator passed to `version_compare`
+	 * @return bool whether the requirement is fulfilled
+	 * @throws InvalidArgumentException if versions specified in an invalid format
+	 */
+	public function isCompatible(string $actual, string $required,
+		string $comparator = '>='): bool {
+
+		if (!preg_match(self::REGEX_SERVER, $actual)) {
+			throw new InvalidArgumentException('server version is invalid');
+		}
+
+		if (preg_match(self::REGEX_MAJOR, $required) === 1) {
+			return $this->compareMajor($actual, $required, $comparator);
+		} else if (preg_match(self::REGEX_MAJOR_MINOR, $required) === 1) {
+			return $this->compareMajorMinor($actual, $required, $comparator);
+		} else if (preg_match(self::REGEX_MAJOR_MINOR_PATCH, $required) === 1) {
+			return $this->compareMajorMinorPatch($actual, $required, $comparator);
+		} else {
+			throw new InvalidArgumentException('required version is invalid');
+		}
+	}
+
+	private function compareMajor(string $actual, string $required,
+		string $comparator) {
+		$actualMajor = explode('.', $actual)[0];
+		$requiredMajor = explode('.', $required)[0];
+
+		return version_compare($actualMajor, $requiredMajor, $comparator);
+	}
+
+	private function compareMajorMinor(string $actual, string $required,
+		string $comparator) {
+		$actualMajor = explode('.', $actual)[0];
+		$actualMinor = explode('.', $actual)[1];
+		$requiredMajor = explode('.', $required)[0];
+		$requiredMinor = explode('.', $required)[1];
+
+		return version_compare("$actualMajor.$actualMinor",
+			"$requiredMajor.$requiredMinor", $comparator);
+	}
+
+	private function compareMajorMinorPatch($actual, $required, $comparator) {
+		$actualMajor = explode('.', $actual)[0];
+		$actualMinor = explode('.', $actual)[1];
+		$actualPatch = explode('.', $actual)[2];
+		$requiredMajor = explode('.', $required)[0];
+		$requiredMinor = explode('.', $required)[1];
+		$requiredPatch = explode('.', $required)[2];
+
+		return version_compare("$actualMajor.$actualMinor.$actualPatch",
+			"$requiredMajor.$requiredMinor.$requiredPatch", $comparator);
+	}
+
+}