fix(analytics): show per-student last seen from login and session activity (#674)

* fix(analytics): show per-student last seen from login and session activity

Return ISO last-seen timestamps from course analytics instead of
pre-formatted strings so the dashboard can format them per student.
Batch-fetch last seen for all students and include session activity
alongside login events for more accurate, distinct values.

Co-authored-by: Rotimi Best <[email protected]>

* fix(analytics): destructure first row from getLastLogin query results

Promise.all returns an array per Drizzle select; nested destructuring
is required so loggedInAt and updatedAt are read from row objects.

Co-authored-by: Rotimi Best <[email protected]>

---------

Co-authored-by: Cursor Agent <[email protected]>
Co-authored-by: Rotimi Best <[email protected]>

apps/dashboard/src/lib/features/course/components/analytics/student-table.svelte

@@ -8,6 +8,7 @@
   import * as Table from '@cio/ui/base/table';
 
   import { courseApi } from '$features/course/api';
+  import { calDateDiff } from '$lib/utils/functions/date';
   import { t } from '$lib/utils/functions/translations';
 
   import EmptyState from './empty-state.svelte';
@@ -125,7 +126,7 @@
             </Table.Cell>
             <Table.Cell class="min-w-[120px] px-4 py-3">
               <span class="ui:text-muted-foreground text-sm">
-                {student.lastSeen}
+                {student.lastSeen ? calDateDiff(student.lastSeen) : $t('analytics.a_while_ago')}
               </span>
             </Table.Cell>
             <Table.Cell class="min-w-[120px] px-4 py-3">

apps/dashboard/src/lib/utils/types/analytics.ts

@@ -21,7 +21,7 @@ export interface StudentOverview {
   exercisesSubmitted: number;
   totalExercises: number;
   averageGrade: number;
-  lastSeen: string;
+  lastSeen: string | undefined;
   progressPercentage: number;
 }
 

packages/core/src/services/course/course.ts

@@ -19,6 +19,7 @@ import {
 } from '@cio/db/queries/group';
 import {
   getLastLogin,
+  getLastSeenForUserIds,
   getLessonsWithCompletion,
   getProfileCourseProgress,
   getUserExercisesStats
@@ -33,7 +34,7 @@ import { updateExercise, updateExercisesSectionId } from '@cio/db/queries/exerci
 import { getProfileById } from '@cio/db/queries/auth';
 import { insertOrganizationMembersOnConflictDoNothing } from '@cio/db/queries/organization';
 import { annotateCourseContentWithProgression } from './progression';
-import { buildCourseContent, calcPercentageWithRounding, formatLastSeen, type CourseContent } from './utils';
+import { buildCourseContent, calcPercentageWithRounding, type CourseContent } from './utils';
 import { guardCourseTypeTransition } from './public-course-guard';
 
 const DEFAULT_CONTENT_GROUPING = true;
@@ -439,15 +440,19 @@ export async function getCourseAnalytics(courseId: string) {
     const exercises = course.contentItems.filter((item) => item.type === ContentType.Exercise);
 
     // Get student analytics
+    const studentProfileIds = students
+      .map((student) => student.profileId)
+      .filter((profileId): profileId is string => profileId !== null);
+    const lastSeenByProfileId = await getLastSeenForUserIds(studentProfileIds);
+
     const studentAnalytics = await Promise.all(
       students
         .filter((student) => student.profileId !== null)
         .map(async (student) => {
           try {
-            const [courseProgress, userExercisesStats, lastLoginDate] = await Promise.all([
+            const [courseProgress, userExercisesStats] = await Promise.all([
               getCourseProgressQuery(courseId, student.profileId!),
-              getUserExercisesStats(courseId, student.profileId!),
-              getLastLogin(student.profileId!)
+              getUserExercisesStats(courseId, student.profileId!)
             ]);
 
             if (!courseProgress) {
@@ -464,6 +469,7 @@ export async function getCourseAnalytics(courseId: string) {
             const lessonsCompleted = courseProgress.lessonsCompleted || 0;
             const totalLessons = courseProgress.lessonsCount || 0;
             const progressPercentage = calcPercentageWithRounding(lessonsCompleted, totalLessons);
+            const lastSeen = lastSeenByProfileId.get(student.profileId!) ?? undefined;
 
             return {
               id: student.profileId,
@@ -477,7 +483,7 @@ export async function getCourseAnalytics(courseId: string) {
               exercisesSubmitted: completedExercises,
               totalExercises,
               averageGrade,
-              lastSeen: formatLastSeen(lastLoginDate),
+              lastSeen,
               progressPercentage
             };
           } catch (error) {
@@ -551,8 +557,7 @@ export async function getUserCourseAnalytics(courseId: string, userId: string) {
       throw new AppError('User profile not found', ErrorCodes.PROFILE_NOT_FOUND, 404);
     }
 
-    // Get last login
-    const lastLoginDate = await getLastLogin(userId);
+    const lastSeen = await getLastLogin(userId);
 
     // Fetch user exercises stats, lessons with completion, and course progress
     const [userExercisesStats, lessons, courseProgress] = await Promise.all([
@@ -582,7 +587,7 @@ export async function getUserCourseAnalytics(courseId: string, userId: string) {
         fullName: profile.fullname || '',
         email: profile.email || '',
         avatarUrl: profile.avatarUrl || '',
-        lastSeen: formatLastSeen(lastLoginDate)
+        lastSeen: lastSeen || undefined
       },
       averageGrade,
       userExercisesStats,

packages/db/src/queries/analytics/analytics.ts

@@ -4,29 +4,122 @@ import { and, desc, eq, inArray, or, sql } from 'drizzle-orm';
 
 import { db } from '@db/drizzle';
 
+function toIsoTimestamp(value: string | Date | null | undefined): string | null {
+  if (!value) {
+    return null;
+  }
+
+  const date = value instanceof Date ? value : new Date(value);
+  if (Number.isNaN(date.getTime())) {
+    return null;
+  }
+
+  return date.toISOString();
+}
+
+function pickLatestTimestamp(...values: Array<string | Date | null | undefined>): string | null {
+  let latest: string | null = null;
+  let latestTime = -Infinity;
+
+  for (const value of values) {
+    const iso = toIsoTimestamp(value);
+    if (!iso) {
+      continue;
+    }
+
+    const time = new Date(iso).getTime();
+    if (time > latestTime) {
+      latestTime = time;
+      latest = iso;
+    }
+  }
+
+  return latest;
+}
+
 /**
- * Gets the last login time for a user
+ * Gets the last seen time for a user from login events and active sessions.
  * @param userId User ID
- * @returns Last login timestamp or undefined
+ * @returns Last seen timestamp or null
  */
 export async function getLastLogin(userId: string): Promise<string | null> {
   try {
-    const [loginEvent] = await db
-      .select({
-        loggedInAt: schema.analyticsLoginEvents.loggedInAt
-      })
-      .from(schema.analyticsLoginEvents)
-      .where(eq(schema.analyticsLoginEvents.userId, userId))
-      .orderBy(desc(schema.analyticsLoginEvents.loggedInAt))
-      .limit(1);
+    const [[loginEvent], [sessionEvent]] = await Promise.all([
+      db
+        .select({
+          loggedInAt: schema.analyticsLoginEvents.loggedInAt
+        })
+        .from(schema.analyticsLoginEvents)
+        .where(eq(schema.analyticsLoginEvents.userId, userId))
+        .orderBy(desc(schema.analyticsLoginEvents.loggedInAt))
+        .limit(1),
+      db
+        .select({
+          updatedAt: schema.session.updatedAt
+        })
+        .from(schema.session)
+        .where(eq(schema.session.userId, userId))
+        .orderBy(desc(schema.session.updatedAt))
+        .limit(1)
+    ]);
 
-    return loginEvent?.loggedInAt;
+    return pickLatestTimestamp(loginEvent?.loggedInAt, sessionEvent?.updatedAt);
   } catch (error) {
-    console.error('getLastLoginAt error:', error);
+    console.error('getLastLogin error:', error);
     return null;
   }
 }
 
+/**
+ * Batch lookup of last seen timestamps for multiple users.
+ * @param userIds User IDs
+ * @returns Map of user ID to last seen ISO timestamp
+ */
+export async function getLastSeenForUserIds(userIds: string[]): Promise<Map<string, string | null>> {
+  const uniqueUserIds = [...new Set(userIds)];
+  const lastSeenByUserId = new Map<string, string | null>(uniqueUserIds.map((userId) => [userId, null]));
+
+  if (uniqueUserIds.length === 0) {
+    return lastSeenByUserId;
+  }
+
+  try {
+    const [loginRows, sessionRows] = await Promise.all([
+      db
+        .select({
+          userId: schema.analyticsLoginEvents.userId,
+          lastSeen: sql<string>`MAX(${schema.analyticsLoginEvents.loggedInAt})`.as('last_seen')
+        })
+        .from(schema.analyticsLoginEvents)
+        .where(inArray(schema.analyticsLoginEvents.userId, uniqueUserIds))
+        .groupBy(schema.analyticsLoginEvents.userId),
+      db
+        .select({
+          userId: schema.session.userId,
+          lastSeen: sql<string>`MAX(${schema.session.updatedAt})`.as('last_seen')
+        })
+        .from(schema.session)
+        .where(inArray(schema.session.userId, uniqueUserIds))
+        .groupBy(schema.session.userId)
+    ]);
+
+    for (const row of loginRows) {
+      const current = lastSeenByUserId.get(row.userId) ?? null;
+      lastSeenByUserId.set(row.userId, pickLatestTimestamp(current, row.lastSeen));
+    }
+
+    for (const row of sessionRows) {
+      const current = lastSeenByUserId.get(row.userId) ?? null;
+      lastSeenByUserId.set(row.userId, pickLatestTimestamp(current, row.lastSeen));
+    }
+
+    return lastSeenByUserId;
+  } catch (error) {
+    console.error('getLastSeenForUserIds error:', error);
+    return lastSeenByUserId;
+  }
+}
+
 /**
  * Gets user exercise statistics for a course
  * @param courseId Course ID