Added /system/time API call (#1223)

* Inital structure for /system/time API call

* Parse arguments for offset

* Correctly parsing parameters

* Fixed implimentation, added to openapi.json

* Modified DOC

* Added Sqlite3 time to output

* Fixed error with negative offset

* Review

Co-authored-by: Bernd Bestel <bernd@berrnd.de>

services/ApplicationService.php

@@ -75,4 +75,44 @@ class ApplicationService extends BaseService
 			'sqlite_version' => $sqliteVersion
 		];
 	}
+
+	private static function convertToUtc(int $timestamp): string
+	{
+		$dt = new \DateTime('now', new \DateTimeZone('UTC'));
+		$dt->setTimestamp($timestamp);
+		return $dt->format('Y-m-d H:i:s');
+	}
+
+	private static function getSqliteLocaltime(int $offset): string
+	{
+		$pdo = new \PDO('sqlite::memory:');
+		if ($offset > 0)
+		{
+			return $pdo->query('SELECT datetime(\'now\', \'+' . $offset . ' seconds\', \'localtime\');')->fetch()[0];
+		}
+		else
+		{
+			return $pdo->query('SELECT datetime(\'now\', \'' . $offset . ' seconds\', \'localtime\');')->fetch()[0];
+		}
+	}
+
+	/**
+	 * Returns the response for the API call /system/time
+	 * @param int $offset an offset in seconds to be applied
+	 * @return array
+	 */
+	public function GetSystemTime(int $offset = 0): array
+	{
+		$timestamp = time() + $offset;
+		$timeLocal = date('Y-m-d H:i:s', $timestamp);
+		$timeUTC = self::convertToUtc($timestamp);
+		return [
+			'timezone' => date_default_timezone_get(),
+			'time_local' => $timeLocal,
+			'time_local_sqlite3' => self::getSqliteLocaltime($offset),
+			'time_utc' => $timeUTC,
+			'timestamp' => $timestamp,
+			'offset' => $offset
+		];
+	}
 }