feat(payments): auto-populate payment due date with middle session date upon class selection

src/utils/classSchedule.js

@@ -42,6 +42,30 @@ export function formatClassSchedule(cls) {
   return days || time || '';
 }
 
+/**
+ * Parses any date format (Jalali string, ISO string, Date object, Persian/Latin digits) into a valid moment object
+ */
+export function parseDateSmart(input) {
+  if (!input) return null;
+  if (input instanceof Date) {
+    const m = moment(input);
+    return m.isValid() ? m : null;
+  }
+  const latin = String(input)
+    .replace(/[۰-۹]/g, (d) => '۰۱۲۳۴۵۶۷۸۹'.indexOf(d))
+    .replace(/[٠-٩]/g, (d) => '٠١٢٣٤٥٦٧٨٩'.indexOf(d))
+    .trim();
+  const isJalaliPattern = /^(1[34]\d{2})[/-](\d{1,2})[/-](\d{1,2})/.test(latin);
+  if (isJalaliPattern) {
+    const m = moment(latin, ['jYYYY/jMM/jDD', 'jYYYY-jMM-jDD', 'jYYYY/jM/jD', 'jYYYY-jM-jD']);
+    if (m.isValid()) return m;
+  }
+  const m = moment(latin);
+  if (m.isValid()) return m;
+  const mJalali = moment(latin, ['jYYYY/jMM/jDD', 'jYYYY-jMM-jDD']);
+  return mJalali.isValid() ? mJalali : null;
+}
+
 /**
  * Calculates the class end date in Jalali (jYYYY/jMM/jDD) based on start date, selected days, and number of sessions.
  * @param {string|Date} startDate - Jalali string (e.g. 1403/01/01) or ISO string / Date
@@ -58,13 +82,8 @@ export function calculateClassEndDate(startDate, days = [], numberOfSessions = 0
     : [];
   if (!validDays.length) return '';
 
-  const latinStartDate = String(startDate)
-    .replace(/[۰-۹]/g, (d) => '۰۱۲۳۴۵۶۷۸۹'.indexOf(d))
-    .replace(/[٠-٩]/g, (d) => '٠١٢٣٤٥٦٧٨٩'.indexOf(d))
-    .trim();
-
-  let current = moment(latinStartDate, ['jYYYY/jMM/jDD', 'YYYY-MM-DD', 'YYYY/MM/DD', moment.ISO_8601]);
-  if (!current.isValid()) return '';
+  let current = parseDateSmart(startDate);
+  if (!current || !current.isValid()) return '';
 
   let count = 0;
   let lastMatchingDate = null;
@@ -85,11 +104,28 @@ export function calculateClassEndDate(startDate, days = [], numberOfSessions = 0
 
 /**
  * Calculates the halfway due date for a class in Jalali (jYYYY/jMM/jDD).
- * If class has 10 sessions, due date is calculated until the 5th session.
+ * If class has 10 sessions, due date is calculated as the date of the 5th session.
  * @param {Object} cls - Class object
+ * @param {Array} [sessions] - Optional array of session objects
  * @returns {string} Jalali formatted date string, or today's date if not calculable
  */
-export function calculateClassMidDate(cls) {
+export function calculateClassMidDate(cls, sessions = []) {
+  if (Array.isArray(sessions) && sessions.length > 0) {
+    const validSessions = sessions
+      .filter((s) => s && (s.day || s.date))
+      .map((s) => ({
+        ...s,
+        momentDate: parseDateSmart(s.day || s.date)
+      }))
+      .filter((s) => s.momentDate && s.momentDate.isValid());
+
+    if (validSessions.length > 0) {
+      validSessions.sort((a, b) => a.momentDate.valueOf() - b.momentDate.valueOf());
+      const midIndex = Math.ceil(validSessions.length / 2) - 1;
+      return validSessions[midIndex].momentDate.locale('fa').format('jYYYY/jMM/jDD');
+    }
+  }
+
   if (!cls) return moment().locale('fa').format('jYYYY/jMM/jDD');
 
   const totalSessions = parseInt(cls.numberOfSessions || cls.course?.sectionCount || 0, 10);
@@ -101,17 +137,17 @@ export function calculateClassMidDate(cls) {
   }
 
   if (cls.startDate && cls.endDate) {
-    const startM = moment(cls.startDate);
-    const endM = moment(cls.endDate);
-    if (startM.isValid() && endM.isValid()) {
+    const startM = parseDateSmart(cls.startDate);
+    const endM = parseDateSmart(cls.endDate);
+    if (startM && startM.isValid() && endM && endM.isValid()) {
       const midTime = startM.valueOf() + (endM.valueOf() - startM.valueOf()) / 2;
       return moment(midTime).locale('fa').format('jYYYY/jMM/jDD');
     }
   }
 
   if (cls.startDate) {
-    const startM = moment(cls.startDate);
-    if (startM.isValid()) return startM.locale('fa').format('jYYYY/jMM/jDD');
+    const startM = parseDateSmart(cls.startDate);
+    if (startM && startM.isValid()) return startM.locale('fa').format('jYYYY/jMM/jDD');
   }
 
   return moment().locale('fa').format('jYYYY/jMM/jDD');