feat: add absence notification and analytics features

- Implemented AbsenceNotifyView for notifying absence with session details.
- Created AnalyticsView for displaying group analytics and managing students at risk.
- Added ClassAttendanceView for marking attendance in classes.
- Defined new schemas for analytics and attendance in shared package.

apps/backend/src/modules/analytics/features/get-attendee-history/use-case.ts

@@ -0,0 +1,83 @@
+import type { PrismaClient } from '@generated/prisma/client';
+import type {
+  AttendanceStatus,
+  AttendeeHistory,
+  ProblemDetails,
+  Result,
+} from '@gruperly/shared';
+import { err, ok } from '@gruperly/shared';
+import { notFoundResourceProblem } from '@/http/problem-builders';
+import prisma from '@/lib/prisma';
+import { type AnalyticsAccessDb, findGroupForUser } from '../../lib/access';
+
+export const HISTORY_SESSIONS_LIMIT = 20;
+
+type GetAttendeeHistoryDeps = {
+  db?: AnalyticsAccessDb & Pick<PrismaClient, 'classSession' | 'attendee' | 'attendance'>;
+};
+
+export class GetAttendeeHistory {
+  constructor(private readonly deps: GetAttendeeHistoryDeps = {}) {}
+
+  async execute(
+    groupId: string,
+    attendeeId: string,
+    userId: string,
+  ): Promise<Result<AttendeeHistory, ProblemDetails>> {
+    const db = this.deps.db ?? prisma;
+
+    const access = await findGroupForUser(db, groupId, userId);
+    if (!access.ok) {
+      return access;
+    }
+
+    const attendee = await db.attendee.findFirst({
+      where: { id: attendeeId, groupId },
+      select: { id: true, fullName: true },
+    });
+    if (!attendee) {
+      return err(notFoundResourceProblem('Attendee', attendeeId));
+    }
+
+    const sessions = await db.classSession.findMany({
+      where: { groupId },
+      orderBy: { startsAt: 'desc' },
+      take: HISTORY_SESSIONS_LIMIT,
+      select: { id: true, startsAt: true },
+    });
+    const sessionIds = sessions.map((session) => session.id);
+
+    const attendances = sessionIds.length
+      ? await db.attendance.findMany({
+        where: { attendeeId, classSessionId: { in: sessionIds } },
+        select: { classSessionId: true, status: true },
+      })
+      : [];
+
+    const statusBySession = new Map<string, AttendanceStatus>(
+      attendances.map((record) => [record.classSessionId, record.status]),
+    );
+
+    const orderedSessions = sessions
+      .slice()
+      .reverse()
+      .map((session) => ({
+        classSessionId: session.id,
+        startsAt: session.startsAt.toISOString(),
+        status: statusBySession.get(session.id) ?? null,
+      }));
+
+    const presentCount = attendances.filter((record) => record.status === 'PRESENT').length;
+    const attendanceRate =
+      sessions.length > 0 ? Math.round((presentCount / sessions.length) * 100) : 0;
+
+    return ok({
+      attendeeId: attendee.id,
+      fullName: attendee.fullName,
+      groupId,
+      groupName: access.value.name,
+      attendanceRate,
+      sessions: orderedSessions,
+    });
+  }
+}