feat: widgets and ai chat

apps/api/src/services/dash.ts

@@ -1,10 +1,15 @@
 import { AppError, ErrorCodes } from '@api/utils/errors';
+import { env } from '@api/config/env';
 import {
   getCourseStats,
   getDashOrgStats,
+  getOrgStudentLoginsByDayOfWeek,
+  getUserLoginStreak,
   getRecentCertifications,
   getTotalCertificatesIssued
 } from '@cio/db/queries/dash';
+import { dashLoginActivityKey } from '@api/utils/redis/key-generators';
+import { logRedisUnavailableOnce, redis } from '@api/utils/redis/redis';
 
 import { OrganisationAnalytics } from '@api/types';
 import { getOrgIdBySiteName } from '@cio/db/queries';
@@ -65,3 +70,101 @@ export async function getOrganisationAnalytics(orgId?: string, siteName?: string
     throw new AppError('Failed to load organisation analytics', ErrorCodes.ORG_ANALYTICS_FETCH_FAILED, 500);
   }
 }
+
+const DAY_LABELS = ['Sun', 'Mon', 'Tue', 'Wed', 'Thu', 'Fri', 'Sat'] as const;
+
+type StudentLoginActivityRow = { day: string; count: number };
+
+/** Redis TTL for login-activity chart payload (1 day). */
+const LOGIN_ACTIVITY_CACHE_TTL_SECONDS = 86_400;
+
+function parseLoginActivityCache(raw: string): StudentLoginActivityRow[] | null {
+  let parsed: unknown;
+  try {
+    parsed = JSON.parse(raw) as unknown;
+  } catch {
+    return null;
+  }
+
+  if (!Array.isArray(parsed) || parsed.length !== 7) {
+    return null;
+  }
+
+  const out: StudentLoginActivityRow[] = [];
+  for (const item of parsed) {
+    if (
+      typeof item !== 'object' ||
+      item === null ||
+      !('day' in item) ||
+      !('count' in item) ||
+      typeof (item as { day: unknown }).day !== 'string' ||
+      typeof (item as { count: unknown }).count !== 'number' ||
+      !Number.isInteger((item as { count: number }).count) ||
+      (item as { count: number }).count < 0
+    ) {
+      return null;
+    }
+
+    out.push({ day: (item as { day: string }).day, count: (item as { count: number }).count });
+  }
+
+  for (const label of DAY_LABELS) {
+    if (!out.some((r) => r.day === label)) {
+      return null;
+    }
+  }
+
+  return out;
+}
+
+/** Day-of-week login chart; results cached in Redis (24h TTL) when `REDIS_URL` is set. */
+export async function getStudentLoginActivity(orgId: string, days: number): Promise<StudentLoginActivityRow[]> {
+  const cacheKey = dashLoginActivityKey(orgId, days);
+
+  if (env.REDIS_URL) {
+    try {
+      const cached = await redis.get(cacheKey);
+      if (cached) {
+        const rows = parseLoginActivityCache(cached);
+        if (rows) {
+          return rows;
+        }
+      }
+    } catch (error) {
+      logRedisUnavailableOnce('Redis get failed for login activity cache, using database', error);
+    }
+  }
+
+  try {
+    const rows = await getOrgStudentLoginsByDayOfWeek(orgId, days);
+
+    const countByDow = new Map(rows.map((r) => [r.dayOfWeek, r.count]));
+
+    const result = DAY_LABELS.map((label, index) => ({
+      day: label,
+      count: countByDow.get(index) ?? 0
+    }));
+
+    if (env.REDIS_URL) {
+      try {
+        await redis.setEx(cacheKey, LOGIN_ACTIVITY_CACHE_TTL_SECONDS, JSON.stringify(result));
+      } catch (error) {
+        logRedisUnavailableOnce('Redis set failed for login activity cache, continuing', error);
+      }
+    }
+
+    return result;
+  } catch (error) {
+    console.error('getStudentLoginActivity error:', error);
+    throw new AppError('Failed to load login activity', ErrorCodes.ORG_ANALYTICS_FETCH_FAILED, 500);
+  }
+}
+
+export async function getCurrentUserLoginStreak(userId: string) {
+  try {
+    return await getUserLoginStreak(userId);
+  } catch (error) {
+    console.error('getCurrentUserLoginStreak error:', error);
+    throw new AppError('Failed to load login streak', ErrorCodes.ORG_ANALYTICS_FETCH_FAILED, 500);
+  }
+}