feat(sms): send class start date, days, and course time

Expose schedule fields on class and invoice templates so SMS can include Jalali start date, weekdays, and hour range.

utils/classSchedule.js

@@ -0,0 +1,85 @@
+'use strict';
+
+const PERSIAN_WEEKDAYS = ['یکشنبه', 'دوشنبه', 'سه‌شنبه', 'چهارشنبه', 'پنجشنبه', 'جمعه', 'شنبه'];
+const IRAN_WEEK_ORDER = [6, 0, 1, 2, 3, 4, 5];
+
+const toDate = (value) => {
+  if (!value) return null;
+  const date = value instanceof Date ? value : new Date(value);
+  return Number.isNaN(date.getTime()) ? null : date;
+};
+
+const formatClockPart = (time) => {
+  const raw = String(time || '').trim();
+  if (!raw) return '';
+  const [hoursRaw, minutesRaw] = raw.split(':');
+  const hours = String(parseInt(hoursRaw, 10));
+  if (hours === 'NaN') return '';
+  if (!minutesRaw || minutesRaw === '00') return hours;
+  return `${hours}:${minutesRaw}`;
+};
+
+const formatCourseTime = (startTime, endTime) => {
+  const start = formatClockPart(startTime);
+  const end = formatClockPart(endTime);
+  if (!start) return '';
+  if (!end) return start;
+  return `از ${start} تا ${end}`;
+};
+
+const weekdayIndex = (value) => {
+  const date = toDate(value);
+  return date ? date.getDay() : null;
+};
+
+const joinFaList = (items) => {
+  if (!items.length) return '';
+  if (items.length === 1) return items[0];
+  if (items.length === 2) return `${items[0]} و ${items[1]}`;
+  return `${items.slice(0, -1).join('، ')} و ${items[items.length - 1]}`;
+};
+
+const formatClassDays = (sessions = []) => {
+  const indexes = [];
+  const seen = new Set();
+  for (const session of sessions) {
+    const dayIndex = weekdayIndex(session?.day);
+    if (dayIndex == null || seen.has(dayIndex)) continue;
+    seen.add(dayIndex);
+    indexes.push(dayIndex);
+  }
+  indexes.sort((a, b) => IRAN_WEEK_ORDER.indexOf(a) - IRAN_WEEK_ORDER.indexOf(b));
+  return joinFaList(indexes.map((index) => PERSIAN_WEEKDAYS[index]).filter(Boolean));
+};
+
+const formatClassStartDate = (value) => {
+  const date = toDate(value);
+  if (!date) return '';
+  try {
+    return date.toLocaleDateString('fa-IR');
+  } catch {
+    return date.toISOString().slice(0, 10);
+  }
+};
+
+const buildClassScheduleContext = (classDoc, sessions = [], currentSession = null) => {
+  const sortedSessions = [...sessions].sort((a, b) => {
+    const left = toDate(a?.day)?.getTime() || 0;
+    const right = toDate(b?.day)?.getTime() || 0;
+    return left - right;
+  });
+  const sessionForTime = currentSession || sortedSessions[0] || null;
+
+  return {
+    classStartDate: formatClassStartDate(classDoc?.startDate || sortedSessions[0]?.day),
+    classDays: formatClassDays(sortedSessions),
+    courseTime: formatCourseTime(sessionForTime?.startTime, sessionForTime?.endTime)
+  };
+};
+
+module.exports = {
+  formatCourseTime,
+  formatClassDays,
+  formatClassStartDate,
+  buildClassScheduleContext
+};