1 files changed, 89 insertions, 0 deletions
diff --git a/classes/TimeHelper.php b/classes/TimeHelper.php
new file mode 100644
index 000000000..453ee0cee
--- /dev/null
+++ b/classes/TimeHelper.php
@@ -0,0 +1,89 @@
+<?php
+class TimeHelper {
+
+	static function smart_date_time(int $timestamp, int $tz_offset = 0, int $owner_uid = null, bool $eta_min = false): string {
+		if (!$owner_uid) $owner_uid = $_SESSION['uid'];
+
+		if ($eta_min && time() + $tz_offset - $timestamp < 3600) {
+			return T_sprintf("%d min", date("i", time() + $tz_offset - $timestamp));
+		} else if (date("Y.m.d", $timestamp) == date("Y.m.d", time() + $tz_offset)) {
+			$format = get_pref(Prefs::SHORT_DATE_FORMAT, $owner_uid);
+			if (strpos((strtolower($format)), "a") === false)
+				return date("G:i", $timestamp);
+			else
+				return date("g:i a", $timestamp);
+		} else if (date("Y", $timestamp) == date("Y", time() + $tz_offset)) {
+			$format = get_pref(Prefs::SHORT_DATE_FORMAT, $owner_uid);
+			return date($format, $timestamp);
+		} else {
+			$format = get_pref(Prefs::LONG_DATE_FORMAT, $owner_uid);
+			return date($format, $timestamp);
+		}
+	}
+
+	static function make_local_datetime(?string $timestamp, bool $long, int $owner_uid = null,
+					bool $no_smart_dt = false, bool $eta_min = false): string {
+
+		if (!$owner_uid) $owner_uid = $_SESSION['uid'];
+		if (!$timestamp) $timestamp = '1970-01-01 0:00';
+
+		global $utc_tz;
+		global $user_tz;
+
+		if (!$utc_tz) $utc_tz = new DateTimeZone('UTC');
+
+		$timestamp = substr($timestamp, 0, 19);
+
+		# We store date in UTC internally
+		$dt = new DateTime($timestamp, $utc_tz);
+
+		$user_tz_string = get_pref(Prefs::USER_TIMEZONE, $owner_uid);
+
+		if ($user_tz_string != 'Automatic') {
+
+			try {
+				if (!$user_tz) $user_tz = new DateTimeZone($user_tz_string);
+			} catch (Exception $e) {
+				$user_tz = $utc_tz;
+			}
+
+			$tz_offset = $user_tz->getOffset($dt);
+		} else {
+			$tz_offset = (int) -($_SESSION["clientTzOffset"] ?? 0);
+		}
+
+		$user_timestamp = $dt->format('U') + $tz_offset;
+
+		if (!$no_smart_dt) {
+			return self::smart_date_time($user_timestamp,
+				$tz_offset, $owner_uid, $eta_min);
+		} else {
+			if ($long)
+				$format = get_pref(Prefs::LONG_DATE_FORMAT, $owner_uid);
+			else
+				$format = get_pref(Prefs::SHORT_DATE_FORMAT, $owner_uid);
+
+			return date($format, $user_timestamp);
+		}
+	}
+
+	static function convert_timestamp(int $timestamp, string $source_tz, string $dest_tz): int {
+
+		try {
+			$source_tz = new DateTimeZone($source_tz);
+		} catch (Exception $e) {
+			$source_tz = new DateTimeZone('UTC');
+		}
+
+		try {
+			$dest_tz = new DateTimeZone($dest_tz);
+		} catch (Exception $e) {
+			$dest_tz = new DateTimeZone('UTC');
+		}
+
+		$dt = new DateTime(date('Y-m-d H:i:s', $timestamp), $source_tz);
+
+		return (int)$dt->format('U') + $dest_tz->getOffset($dt);
+	}
+
+}