feat: log staff sign-in and sign-out and force logout at a set time

apps/api/src/attendance/attendance-time.ts

@@ -0,0 +1,44 @@
+const TEHRAN = 'Asia/Tehran';
+
+export type AttendanceKind = 'login' | 'logout' | 'forced_logout';
+
+export function tehranDateKey(date: Date): string {
+  const parts = new Intl.DateTimeFormat('en-CA', {
+    timeZone: TEHRAN,
+    year: 'numeric',
+    month: '2-digit',
+    day: '2-digit',
+  }).format(date);
+  return parts;
+}
+
+/** ساعت HH:mm امروز به وقت تهران، به صورت لحظهٔ مطلق */
+export function tehranCutoff(now: Date, hhmm: string): Date | null {
+  const match = /^([01]\d|2[0-3]):([0-5]\d)$/.exec(hhmm.trim());
+  if (!match) return null;
+  const day = tehranDateKey(now);
+  return new Date(`${day}T${match[1]}:${match[2]}:00+03:30`);
+}
+
+export function isPastLogoutTime(now: Date, hhmm: string | null | undefined): boolean {
+  if (!hhmm) return false;
+  const cutoff = tehranCutoff(now, hhmm);
+  if (!cutoff) return false;
+  return now.getTime() >= cutoff.getTime();
+}
+
+export function loggedInAfterCutoff(at: Date, hhmm: string | null | undefined): boolean {
+  if (!hhmm) return false;
+  const cutoff = tehranCutoff(at, hhmm);
+  if (!cutoff) return false;
+  return at.getTime() >= cutoff.getTime();
+}
+
+export function tehranClock(date: Date): string {
+  return new Intl.DateTimeFormat('fa-IR', {
+    timeZone: TEHRAN,
+    hour: '2-digit',
+    minute: '2-digit',
+    hourCycle: 'h23',
+  }).format(date);
+}