Improve attendance completion checks and expose recorded counts.

Only count existing enrolled students when deciding if a session is fully recorded, and return per-session attendance totals for the dashboard list.

components/sessions/sessionService.js

@@ -3,6 +3,7 @@
 const Session = require('./sessionModel');
 const Course = require('../courses/courseModel');
 const Class = require('../classes/classModel');
+const User = require('../users/userModel');
 const Professor = require('../professors/professorModel');
 const AppError = require('../../utils/AppError');
 const eventEmitter = require('../../events/eventEmitter');
@@ -124,7 +125,31 @@ const buildStudentsByClassId = async (sessions) => {
   if (!classIds.length) return new Map();
 
   const classes = await Class.find({ _id: { $in: classIds } }).select('students').lean();
-  return new Map(classes.map((cls) => [String(cls._id), cls.students || []]));
+  const allStudentIds = [...new Set(
+    classes.flatMap((cls) => (cls.students || []).map(normalizeId)).filter(Boolean)
+  )];
+
+  let existingSet = new Set();
+  if (allStudentIds.length) {
+    const existingUsers = await User.find({ _id: { $in: allStudentIds } }).select('_id').lean();
+    existingSet = new Set(existingUsers.map((user) => normalizeId(user._id)));
+  }
+
+  return new Map(classes.map((cls) => {
+    const validStudentIds = (cls.students || [])
+      .map(normalizeId)
+      .filter((id) => existingSet.has(id));
+    return [String(cls._id), validStudentIds];
+  }));
+};
+
+const getValidStudentIdsForClass = async (classItem) => {
+  if (!classItem) return [];
+  const rawIds = (classItem.students || []).map(normalizeId).filter(Boolean);
+  if (!rawIds.length) return [];
+  const existingUsers = await User.find({ _id: { $in: rawIds } }).select('_id').lean();
+  const existingSet = new Set(existingUsers.map((user) => normalizeId(user._id)));
+  return rawIds.filter((id) => existingSet.has(id));
 };
 
 const isSessionDue = (session) => {
@@ -156,12 +181,21 @@ const hasCompleteAttendance = (session, studentsByClassId = null) => {
 const isAttendancePending = (session, studentsByClassId = null) =>
   isSessionDue(session) && !hasCompleteAttendance(session, studentsByClassId);
 
-const enrichSessionAttendance = (session, studentsByClassId = null) => ({
+const enrichSessionAttendance = (session, studentsByClassId = null) => {
+  const studentIds = getClassStudentIds(session, studentsByClassId);
+  const recordedIds = getRecordedUserIds(session);
+  const studentSet = new Set(studentIds);
+  const attendanceRecordedCount = recordedIds.filter((id) => studentSet.has(id)).length;
+
+  return {
     ...session,
     isDue: isSessionDue(session),
+    attendanceTotalCount: studentIds.length,
+    attendanceRecordedCount,
     attendanceComplete: hasCompleteAttendance(session, studentsByClassId),
     attendancePending: isAttendancePending(session, studentsByClassId)
-});
+  };
+};
 
 const filterByAttendanceScope = (sessions, scope, studentsByClassId = null) => {
   const dueSessions = sessions.filter(isSessionDue);
@@ -351,7 +385,12 @@ const updateSessionAttendance = async (sessionId, attendanceList, recordedBy = n
   await session.save();
 
   const classItem = await Class.findById(session.class).select('students').lean();
-  if (classItem && hasCompleteAttendance({ ...session.toObject(), class: classItem }) && session.status !== 'cancelled') {
+  const validStudentIds = await getValidStudentIdsForClass(classItem);
+  if (
+    classItem
+    && hasCompleteAttendance({ ...session.toObject(), class: { ...classItem, students: validStudentIds } })
+    && session.status !== 'cancelled'
+  ) {
     session.status = 'held';
     await session.save();
   }