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');

src/utils/classSchedule.test.js

@@ -44,5 +44,40 @@ describe('class schedule display', () => {
     // Session 5: 1403/01/18 (Sat)
     assert.equal(midDate, '1403/01/18');
   });
+
+  it('calculates class mid date from an array of existing sessions', () => {
+    const sessions10 = [
+      { day: '2024-04-01' },
+      { day: '2024-04-03' },
+      { day: '2024-04-05' },
+      { day: '2024-04-08' },
+      { day: '2024-04-10' }, // 5th session (index 4) -> 1403/01/22
+      { day: '2024-04-12' },
+      { day: '2024-04-15' },
+      { day: '2024-04-17' },
+      { day: '2024-04-19' },
+      { day: '2024-04-22' }
+    ];
+    const midDate10 = calculateClassMidDate({ name: 'Class A' }, sessions10);
+    assert.equal(midDate10, '1403/01/22');
+
+    const sessions9 = sessions10.slice(0, 9); // 5th session is still index 4
+    const midDate9 = calculateClassMidDate({ name: 'Class A' }, sessions9);
+    assert.equal(midDate9, '1403/01/22');
+
+    const sessions4 = sessions10.slice(0, 4); // 2nd session is index 1 -> 2024-04-03 -> 1403/01/15
+    const midDate4 = calculateClassMidDate({ name: 'Class A' }, sessions4);
+    assert.equal(midDate4, '1403/01/15');
+  });
+
+  it('calculates class mid date with Gregorian ISO string startDate', () => {
+    // 2024-03-20 is 1403/01/01 (Wednesday)
+    const midDate = calculateClassMidDate({
+      startDate: '2024-03-20T00:00:00.000Z',
+      days: [6, 2],
+      numberOfSessions: 10
+    });
+    assert.equal(midDate, '1403/01/18');
+  });
 });
 

src/views/payments/PaymentListView.vue

@@ -180,6 +180,7 @@ import { useToast } from '@/composables/useToast';
 import { paymentApi } from '@/api/paymentApi';
 import { userApi } from '@/api/userApi';
 import { classApi } from '@/api/classApi';
+import { sessionApi } from '@/api/sessionApi';
 import PageHeader from '@/components/common/PageHeader.vue';
 import DataTableWrapper from '@/components/common/DataTableWrapper.vue';
 import ConfirmDeleteDialog from '@/components/common/ConfirmDeleteDialog.vue';
@@ -263,7 +264,7 @@ const eligibleUsers = computed(() => {
   return usersList.value.filter((u) => eligibleIds?.has(String(u._id || u.id)));
 });
 
-const onClassesSelected = () => {
+const onClassesSelected = async () => {
   if (createForm.user && !eligibleUsers.value.some((u) => (u._id || u.id) === createForm.user)) {
     createForm.user = null;
   }
@@ -287,8 +288,24 @@ const onClassesSelected = () => {
   if ((createForm.discount || 0) > (createForm.amount || 0)) {
     createForm.discount = createForm.amount || 0;
   }
-  if (!createForm.dueDate) {
-    createForm.dueDate = getTodayJalali();
+
+  const selectedClassId = createForm.classes[createForm.classes.length - 1];
+  const selectedClass = classesList.value.find((item) => String(item._id || item.id) === String(selectedClassId));
+  if (selectedClass) {
+    try {
+      const res = await sessionApi.getAll({
+        class: selectedClassId,
+        sortBy: 'day',
+        sortOrder: 'asc',
+        limit: 100
+      });
+      const data = res.data || res;
+      const rawSessions = data.items || data.sessions || data.data || data || [];
+      const sessionList = Array.isArray(rawSessions) ? rawSessions : [];
+      createForm.dueDate = calculateClassMidDate(selectedClass, sessionList);
+    } catch (e) {
+      createForm.dueDate = calculateClassMidDate(selectedClass);
+    }
   }
 };