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]>
2026-06-23 10:09:47 +01:00
parent bbdb2e9419
commit f2d7afc590
4 changed files with 121 additions and 22 deletions
@@ -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