feat: Add user role retrieval, enhance recommended course filtering and detail, and introduce new k6 load tests.

Backend/src/controllers/RecommendedCoursesController.ts

@@ -20,10 +20,14 @@ export class RecommendedCoursesController {
     @SuccessResponse('200', 'Approved courses retrieved successfully')
     @Response('401', 'Unauthorized')
     @Response('403', 'Forbidden - Admin only')
-    public async listApprovedCourses(@Request() request: any): Promise<ListApprovedCoursesResponse> {
+    public async listApprovedCourses(
+        @Request() request: any,
+        @Query() search?: string,
+        @Query() categoryId?: number
+    ): Promise<ListApprovedCoursesResponse> {
         const token = request.headers.authorization?.replace('Bearer ', '');
         if (!token) throw new ValidationError('No token provided');
-        return await RecommendedCoursesService.listApprovedCourses(token);
+        return await RecommendedCoursesService.listApprovedCourses(token, { search, categoryId });
     }
 
     /**

Backend/src/controllers/UserController.ts

@@ -10,7 +10,8 @@ import {
     ChangePasswordResponse,
     updateAvatarResponse,
     SendVerifyEmailResponse,
-    VerifyEmailResponse
+    VerifyEmailResponse,
+    rolesResponse
 } from '../types/user.types';
 import { ChangePassword } from '../types/auth.types';
 import { profileUpdateSchema, changePasswordSchema } from "../validators/user.validator";
@@ -56,6 +57,18 @@ export class UserController {
         return await this.userService.updateProfile(token, body);
     }
 
+    @Get('roles')
+    @Security('jwt')
+    @SuccessResponse('200', 'Roles retrieved successfully')
+    @Response('401', 'Invalid or expired token')
+    public async getRoles(@Request() request: any): Promise<rolesResponse> {
+        const token = request.headers.authorization?.replace('Bearer ', '');
+        if (!token) {
+            throw new ValidationError('No token provided');
+        }
+        return await this.userService.getRoles(token);
+    }
+
     /**
      * Change password
      * @summary Change user password using old password

Backend/src/services/AdminCourseApproval.service.ts

@@ -113,7 +113,7 @@ export class AdminCourseApprovalService {
     /**
      * Get course details for admin review
      */
-    static async getCourseDetail(token: string,courseId: number): Promise<GetCourseDetailForAdminResponse> {
+    static async getCourseDetail(token: string, courseId: number): Promise<GetCourseDetailForAdminResponse> {
         try {
             const course = await prisma.course.findUnique({
                 where: { id: courseId },
@@ -133,7 +133,11 @@ export class AdminCourseApprovalService {
                     },
                     chapters: {
                         orderBy: { sort_order: 'asc' },
-                        include: {
+                        select: {
+                            id: true,
+                            title: true,
+                            sort_order: true,
+                            is_published: true,
                             lessons: {
                                 orderBy: { sort_order: 'asc' },
                                 select: {

Backend/src/services/RecommendedCourses.service.ts

@@ -8,7 +8,8 @@ import {
     ListApprovedCoursesResponse,
     GetCourseByIdResponse,
     ToggleRecommendedResponse,
-    RecommendedCourseData
+    RecommendedCourseData,
+    RecommendedCourseDetailData
 } from '../types/RecommendedCourses.types';
 import { auditService } from './audit.service';
 import { AuditAction } from '@prisma/client';
@@ -18,10 +19,24 @@ export class RecommendedCoursesService {
     /**
      * List all approved courses (for admin to manage recommendations)
      */
-    static async listApprovedCourses(token: string): Promise<ListApprovedCoursesResponse> {
+    static async listApprovedCourses(
+        token: string,
+        filters?: { search?: string; categoryId?: number }
+    ): Promise<ListApprovedCoursesResponse> {
         try {
+            const { search, categoryId } = filters ?? {};
+
             const courses = await prisma.course.findMany({
-                where: { status: 'APPROVED' },
+                where: {
+                    status: 'APPROVED',
+                    ...(categoryId ? { category_id: categoryId } : {}),
+                    ...(search ? {
+                        OR: [
+                            { title: { path: ['th'], string_contains: search } },
+                            { title: { path: ['en'], string_contains: search } }
+                        ]
+                    } : {})
+                },
                 orderBy: [
                     { is_recommended: 'desc' },
                     { updated_at: 'desc' }
@@ -40,9 +55,9 @@ export class RecommendedCoursesService {
                             }
                         }
                     },
-                    chapters: {
-                        include: {
-                            lessons: true
+                    _count: {
+                        select: {
+                            chapters: true
                         }
                     }
                 }
@@ -81,8 +96,7 @@ export class RecommendedCoursesService {
                         is_primary: i.is_primary,
                         user: i.user
                     })),
-                    chapters_count: course.chapters.length,
-                    lessons_count: course.chapters.reduce((sum, ch) => sum + ch.lessons.length, 0)
+                    chapters_count: course._count.chapters,
                 } as RecommendedCourseData;
             }));
 
@@ -158,7 +172,7 @@ export class RecommendedCoursesService {
                 }
             }
 
-            const data: RecommendedCourseData = {
+            const data: RecommendedCourseDetailData = {
                 id: course.id,
                 title: course.title as { th: string; en: string },
                 slug: course.slug,
@@ -181,8 +195,15 @@ export class RecommendedCoursesService {
                     is_primary: i.is_primary,
                     user: i.user
                 })),
-                chapters_count: course.chapters.length,
-                lessons_count: course.chapters.reduce((sum, ch) => sum + ch.lessons.length, 0)
+                chapters: course.chapters.map(ch => ({
+                    id: ch.id,
+                    title: ch.title as { th: string; en: string },
+                    sort_order: ch.sort_order,
+                    lessons: ch.lessons.map(l => ({
+                        id: l.id,
+                        title: l.title as { th: string; en: string }
+                    }))
+                }))
             };
 
             return {

Backend/src/services/courses.service.ts

@@ -103,18 +103,53 @@ export class CoursesService {
             const course = await prisma.course.findFirst({
                 where: {
                     id,
-                    status: 'APPROVED' // Only show approved courses to students
+                    status: 'APPROVED'
                 },
                 include: {
+                    creator: {
+                        select: {
+                            id: true,
+                            username: true,
+                            email: true,
+                            profile: {
+                                select: {
+                                    first_name: true,
+                                    last_name: true,
+                                    avatar_url: true
+                                }
+                            }
+                        }
+                    },
+                    instructors: {
+                        include: {
+                            user: {
+                                select: {
+                                    id: true,
+                                    username: true,
+                                    email: true,
+                                    profile: {
+                                        select: {
+                                            first_name: true,
+                                            last_name: true,
+                                            avatar_url: true
+                                        }
+                                    }
+                                }
+                            }
+                        }
+                    },
+                    category: {
+                        select: { id: true, name: true }
+                    },
                     chapters: {
+                        orderBy: { sort_order: 'asc' },
                         select: {
                             id: true,
                             title: true,
+                            sort_order: true,
                             lessons: {
-                                select: {
-                                    id: true,
-                                    title: true,
-                                }
+                                orderBy: { sort_order: 'asc' },
+                                select: { id: true, title: true }
                             }
                         }
                     }
@@ -138,12 +173,69 @@ export class CoursesService {
                     logger.warn(`Failed to generate presigned URL for thumbnail: ${err}`);
                 }
             }
+
+            // Generate presigned URL for creator avatar
+            let creator_avatar_url: string | null = null;
+            if (course.creator.profile?.avatar_url) {
+                try {
+                    creator_avatar_url = await getPresignedUrl(course.creator.profile.avatar_url, 3600);
+                } catch (err) {
+                    logger.warn(`Failed to generate presigned URL for creator avatar: ${err}`);
+                }
+            }
+
+            // Generate presigned URLs for instructor avatars
+            const instructorsWithAvatar = await Promise.all(course.instructors.map(async (i) => {
+                let avatar_url: string | null = null;
+                if (i.user.profile?.avatar_url) {
+                    try {
+                        avatar_url = await getPresignedUrl(i.user.profile.avatar_url, 3600);
+                    } catch (err) {
+                        logger.warn(`Failed to generate presigned URL for instructor avatar: ${err}`);
+                    }
+                }
+                return {
+                    user_id: i.user_id,
+                    is_primary: i.is_primary,
+                    user: {
+                        ...i.user,
+                        profile: i.user.profile ? {
+                            ...i.user.profile,
+                            avatar_url
+                        } : null
+                    }
+                };
+            }));
+
             return {
                 code: 200,
                 message: 'Course fetched successfully',
                 data: {
                     ...course,
+                    title: course.title as { th: string; en: string },
+                    description: course.description as { th: string; en: string },
                     thumbnail_url: thumbnail_presigned_url,
+                    creator: {
+                        ...course.creator,
+                        profile: course.creator.profile ? {
+                            ...course.creator.profile,
+                            avatar_url: creator_avatar_url
+                        } : null
+                    },
+                    instructors: instructorsWithAvatar,
+                    category: course.category ? {
+                        id: course.category.id,
+                        name: course.category.name as { th: string; en: string }
+                    } : null,
+                    chapters: course.chapters.map(ch => ({
+                        id: ch.id,
+                        title: ch.title as { th: string; en: string },
+                        sort_order: ch.sort_order,
+                        lessons: ch.lessons.map(l => ({
+                            id: l.id,
+                            title: l.title as { th: string; en: string }
+                        }))
+                    }))
                 },
             };
         } catch (error) {

Backend/src/services/user.service.ts

@@ -14,7 +14,8 @@ import {
     updateAvatarRequest,
     updateAvatarResponse,
     SendVerifyEmailResponse,
-    VerifyEmailResponse
+    VerifyEmailResponse,
+    rolesResponse
 } from '../types/user.types';
 import nodemailer from 'nodemailer';
 import { UnauthorizedError, ValidationError, ForbiddenError } from '../middleware/errorHandler';
@@ -212,6 +213,30 @@ export class UserService {
         }
     }
 
+    async getRoles(token: string): Promise<rolesResponse> {
+        try {
+            jwt.verify(token, config.jwt.secret);
+            const roles = await prisma.role.findMany({
+                select: {
+                    id: true,
+                    code: true
+                }
+            });
+            return { roles };
+        } catch (error) {
+            if (error instanceof jwt.TokenExpiredError) {
+                logger.error('JWT token expired:', error);
+                throw new UnauthorizedError('Token expired');
+            }
+            if (error instanceof jwt.JsonWebTokenError) {
+                logger.error('Invalid JWT token:', error);
+                throw new UnauthorizedError('Invalid token');
+            }
+            logger.error('Failed to get roles', { error });
+            throw error;
+        }
+    }
+
     /**
      * Upload avatar picture to MinIO
      */

Backend/src/types/RecommendedCourses.types.ts

@@ -1,14 +1,10 @@
 import { MultiLanguageText } from './index';
 
-// ============================================
-// Request Types
-// ============================================
-
-
 // ============================================
 // Response Types
 // ============================================
 
+/** ใช้ใน listApprovedCourses — มีแค่ chapters_count */
 export interface RecommendedCourseData {
     id: number;
     title: MultiLanguageText;
@@ -41,7 +37,19 @@ export interface RecommendedCourseData {
         };
     }>;
     chapters_count: number;
-    lessons_count: number;
+}
+
+/** ใช้ใน getCourseById — มี chapters + lessons พร้อมชื่อ */
+export interface RecommendedCourseDetailData extends Omit<RecommendedCourseData, 'chapters_count'> {
+    chapters: {
+        id: number;
+        title: MultiLanguageText;
+        sort_order: number;
+        lessons: {
+            id: number;
+            title: MultiLanguageText;
+        }[];
+    }[];
 }
 
 export interface ListApprovedCoursesResponse {
@@ -54,7 +62,7 @@ export interface ListApprovedCoursesResponse {
 export interface GetCourseByIdResponse {
     code: number;
     message: string;
-    data: RecommendedCourseData;
+    data: RecommendedCourseDetailData;
 }
 
 export interface ToggleRecommendedResponse {

Backend/src/types/courses.types.ts

@@ -1,4 +1,5 @@
 import { Course } from '@prisma/client';
+import { MultiLanguageText } from './index';
 
 export interface ListCoursesInput {
     category_id?: number;
@@ -18,8 +19,47 @@ export interface listCourseResponse {
     totalPages: number;
 }
 
+export interface CourseDetail extends Omit<Course, 'title' | 'description'> {
+    title: MultiLanguageText;
+    description: MultiLanguageText;
+    creator: {
+        id: number;
+        username: string;
+        email: string;
+        profile: {
+            first_name: string;
+            last_name: string;
+            avatar_url: string | null;
+        } | null;
+    };
+    instructors: {
+        user_id: number;
+        is_primary: boolean;
+        user: {
+            id: number;
+            username: string;
+            email: string;
+            profile: {
+                first_name: string;
+                last_name: string;
+                avatar_url: string | null;
+            } | null;
+        };
+    }[];
+    category: { id: number; name: MultiLanguageText } | null;
+    chapters: {
+        id: number;
+        title: MultiLanguageText;
+        sort_order: number;
+        lessons: {
+            id: number;
+            title: MultiLanguageText;
+        }[];
+    }[];
+}
+
 export interface getCourseResponse {
     code: number;
     message: string;
-    data: Course | null;
+    data: CourseDetail | null;
 }

Backend/src/types/user.types.ts

@@ -59,6 +59,14 @@ export interface ProfileUpdateResponse {
     };
 };
 
+export interface role {
+    id: number;
+    code: string;
+}
+
+export interface rolesResponse {
+   roles: role[];
+}
 
 export interface ChangePasswordRequest {
     old_password: string;

Backend/tests/k6/enroll-load-test.js

@@ -0,0 +1,160 @@
+// Backend/tests/k6/enroll-load-test.js
+//
+// จำลองนักเรียนหลายคน login แล้ว enroll คอร์สพร้อมกัน
+//
+// Flow:
+//   1. Login
+//   2. Enroll คอร์ส
+//   3. ตรวจสอบ enrolled courses
+//
+// Usage:
+//   k6 run -e APP_URL=http://192.168.1.137:4000 -e COURSE_ID=1 tests/k6/enroll-load-test.js
+
+import http from 'k6/http';
+import { check, sleep, group } from 'k6';
+import { Rate, Trend, Counter } from 'k6/metrics';
+import { SharedArray } from 'k6/data';
+
+// ─── Custom Metrics ───────────────────────────────────────────────────────────
+const errorRate    = new Rate('errors');
+const loginTime    = new Trend('login_duration', true);
+const enrollTime   = new Trend('enroll_duration', true);
+const enrolledCount = new Counter('successful_enrollments');
+
+// ─── Load student credentials ─────────────────────────────────────────────────
+const students = new SharedArray('students', function () {
+  return JSON.parse(open('./test-credentials.json')).students;
+});
+
+// ─── Config ───────────────────────────────────────────────────────────────────
+const BASE_URL  = __ENV.APP_URL   || 'http://192.168.1.137:4000';
+const COURSE_ID = __ENV.COURSE_ID || '1';
+
+// ─── Test Options ─────────────────────────────────────────────────────────────
+export const options = {
+  stages: [
+    { duration: '20s', target: 10 },  // Ramp up
+    { duration: '1m',  target: 30 },  // Increase
+    { duration: '30s', target: 50 },  // Peak: 50 คน enroll พร้อมกัน
+    { duration: '30s', target: 0 },   // Ramp down
+  ],
+  thresholds: {
+    'login_duration':  ['p(95)<2000'],  // Login < 2s
+    'enroll_duration': ['p(95)<1000'],  // Enroll < 1s
+    'errors':          ['rate<0.05'],
+    'http_req_failed': ['rate<0.05'],
+  },
+};
+
+// ─── Helper ───────────────────────────────────────────────────────────────────
+function jsonHeaders(token) {
+  const h = { 'Content-Type': 'application/json' };
+  if (token) h['Authorization'] = `Bearer ${token}`;
+  return h;
+}
+
+// ─── Main ─────────────────────────────────────────────────────────────────────
+export default function () {
+  const student = students[__VU % students.length];
+  let token = null;
+
+  // ── Step 1: Login ──────────────────────────────────────────────────────────
+  group('1. Login', () => {
+    const res = http.post(
+      `${BASE_URL}/api/auth/login`,
+      JSON.stringify({ email: student.email, password: student.password }),
+      { headers: jsonHeaders(null) }
+    );
+
+    loginTime.add(res.timings.duration);
+    errorRate.add(res.status !== 200);
+
+    check(res, {
+      'login: status 200': (r) => r.status === 200,
+      'login: has token':  (r) => { try { return !!r.json('data.token'); } catch { return false; } },
+    });
+
+    if (res.status === 200) {
+      try { token = res.json('data.token'); } catch {}
+    }
+  });
+
+  if (!token) {
+    console.warn(`[VU ${__VU}] Login failed for ${student.email} — skipping`);
+    sleep(1);
+    return;
+  }
+
+  sleep(0.5);
+
+  // ── Step 2: Enroll ─────────────────────────────────────────────────────────
+  group('2. Enroll Course', () => {
+    const res = http.post(
+      `${BASE_URL}/api/students/courses/${COURSE_ID}/enroll`,
+      null,
+      { headers: jsonHeaders(token) }
+    );
+
+    enrollTime.add(res.timings.duration);
+
+    // 200 = enrolled, 409 = already enrolled (ถือว่าโอเค)
+    const ok = res.status === 200 || res.status === 409;
+    errorRate.add(!ok);
+
+    if (res.status === 200) enrolledCount.add(1);
+
+    check(res, {
+      'enroll: 200 or 409':    (r) => r.status === 200 || r.status === 409,
+      'enroll: fast response': (r) => r.timings.duration < 1000,
+    });
+  });
+
+  sleep(0.5);
+
+  // ── Step 3: Verify — ดึงรายการคอร์สที่ลงทะเบียน ─────────────────────────
+  group('3. Get Enrolled Courses', () => {
+    const res = http.get(
+      `${BASE_URL}/api/students/courses`,
+      { headers: jsonHeaders(token) }
+    );
+
+    errorRate.add(res.status !== 200);
+
+    check(res, {
+      'enrolled courses: status 200': (r) => r.status === 200,
+    });
+  });
+
+  sleep(1);
+}
+
+// ─── Summary ──────────────────────────────────────────────────────────────────
+export function handleSummary(data) {
+  const m   = data.metrics;
+  const avg = (k) => m[k]?.values?.avg?.toFixed(0) ?? 'N/A';
+  const p95 = (k) => m[k]?.values?.['p(95)']?.toFixed(0) ?? 'N/A';
+  const rate = (k) => ((m[k]?.values?.rate ?? 0) * 100).toFixed(2);
+  const cnt  = (k) => m[k]?.values?.count ?? 0;
+
+  return {
+    stdout: `
+╔══════════════════════════════════════════════════════════╗
+║              Course Enroll — Load Test                   ║
+╠══════════════════════════════════════════════════════════╣
+║  Course ID  : ${String(COURSE_ID).padEnd(43)}║
+╠══════════════════════════════════════════════════════════╣
+║  RESPONSE TIMES (avg / p95)                              ║
+║  Login          : ${avg('login_duration')}ms / ${p95('login_duration')}ms
+║  Enroll         : ${avg('enroll_duration')}ms / ${p95('enroll_duration')}ms
+╠══════════════════════════════════════════════════════════╣
+║  COUNTS                                                  ║
+║  Total Requests     : ${String(cnt('http_reqs')).padEnd(33)}║
+║  New Enrollments    : ${String(cnt('successful_enrollments')).padEnd(33)}║
+╠══════════════════════════════════════════════════════════╣
+║  ERROR RATES                                             ║
+║  HTTP Failed    : ${(rate('http_req_failed') + '%').padEnd(39)}║
+║  Custom Errors  : ${(rate('errors') + '%').padEnd(39)}║
+╚══════════════════════════════════════════════════════════╝
+`,
+  };
+}

Backend/tests/k6/video-watching-load-test.js

@@ -29,6 +29,7 @@ const progressSaveTime  = new Trend('progress_save_duration', true);
 const completeLessonTime = new Trend('complete_lesson_duration', true);
 const completedCount    = new Counter('completed_lessons');
 const progressSaveCount = new Counter('progress_saves');
+const videoLoadTime     = new Trend('video_load_duration', true);
 
 // ─── Load student credentials ────────────────────────────────────────────────
 // อ่านจาก test-credentials.json (50 accounts)
@@ -42,7 +43,7 @@ const COURSE_ID = __ENV.COURSE_ID || '1';
 const LESSON_ID = __ENV.LESSON_ID || '1';
 
 // วีดีโอความยาว (วินาที) — ปรับตามจริง
-const VIDEO_DURATION_SECONDS = parseInt(__ENV.VIDEO_DURATION || '300'); // default 5 นาที
+const VIDEO_DURATION_SECONDS = parseInt(__ENV.VIDEO_DURATION || '98'); // default 5 นาที
 
 // save progress interval: ทุก 5 วินาที (เหมือน client จริง)
 // แต่ในการ test เราจะ simulate เร็วขึ้นโดยใช้ sleep น้อยลง
@@ -63,6 +64,7 @@ export const options = {
     'login_duration':           ['p(95)<2000'],    // Login < 2s
     'course_learning_duration': ['p(95)<1000'],    // Load course page < 1s
     'lesson_load_duration':     ['p(95)<1000'],    // Load lesson < 1s
+    'video_load_duration':      ['p(95)<3000'],    // Fetch video from MinIO < 3s
     'progress_save_duration':   ['p(95)<500'],     // Save progress < 500ms (critical — บ่อย)
     'complete_lesson_duration': ['p(95)<1000'],    // Complete lesson < 1s
 
@@ -79,116 +81,114 @@ function jsonHeaders(token) {
   return h;
 }
 
+// ─── Per-VU persistent state (จำข้ามรอบ iteration) ──────────────────────────
+// ตัวแปรนี้อยู่ระดับ module → k6 สร้างแยกต่างหากสำหรับแต่ละ VU
+// ค่าจะถูกจำไว้ตลอดอายุของ VU (ข้ามหลายรอบ iteration)
+let vuToken       = null;    // token ที่ login ไว้แล้ว
+let vuSetupDone   = false;   // เคย load course+lesson แล้วหรือยัง
+let vuProgress    = 0;       // ตำแหน่งวีดีโอปัจจุบัน (วินาที)
+let vuCompleted   = false;   // lesson complete แล้วหรือยัง
+
 // ─── Main ─────────────────────────────────────────────────────────────────────
 export default function () {
-  // แต่ละ VU ใช้ account คนละคน (round-robin ถ้า VU มากกว่า 50)
   const student = students[__VU % students.length];
 
-  let token = null;
+  // ── Step 1: Login (ทำครั้งเดียวตอน VU เริ่มต้น หรือถ้า token หาย) ─────────
+  if (!vuToken) {
+    group('1. Login', () => {
+      const res = http.post(
+        `${BASE_URL}/api/auth/login`,
+        JSON.stringify({ email: student.email, password: student.password }),
+        { headers: jsonHeaders(null) }
+      );
 
-  // ── Step 1: Login ──────────────────────────────────────────────────────────
-  group('1. Login', () => {
-    const res = http.post(
-      `${BASE_URL}/api/auth/login`,
-      JSON.stringify({ identifier: student.email, password: student.password }),
-      { headers: jsonHeaders(null) }
-    );
+      loginTime.add(res.timings.duration);
+      const ok = res.status === 200;
+      errorRate.add(!ok);
 
-    loginTime.add(res.timings.duration);
-    const ok = res.status === 200;
-    errorRate.add(!ok);
+      check(res, {
+        'login: status 200': (r) => r.status === 200,
+        'login: has token':  (r) => { try { return !!r.json('data.token'); } catch { return false; } },
+      });
 
-    check(res, {
-      'login: status 200':  (r) => r.status === 200,
-      'login: has token':   (r) => {
-        try { return !!r.json('data.token'); } catch { return false; }
-      },
+      if (ok) {
+        try { vuToken = res.json('data.token'); } catch {}
+      }
     });
 
-    if (ok) {
-      try { token = res.json('data.token'); } catch {}
+    if (!vuToken) {
+      console.warn(`[VU ${__VU}] Login failed for ${student.email} — skipping`);
+      sleep(2);
+      return;
     }
-  });
-
-  if (!token) {
-    console.warn(`[VU ${__VU}] Login failed for ${student.email} — skipping`);
-    sleep(2);
-    return;
   }
 
-  sleep(1);
+  // ── Step 2 (removed): Enroll ทำผ่าน enroll-load-test.js แยกต่างหาก ─────────
 
-  // ── Step 2: Enroll (ถ้ายังไม่ได้ enroll) ──────────────────────────────────
-  group('2. Enroll Course', () => {
-    const res = http.post(
-      `${BASE_URL}/api/students/courses/${COURSE_ID}/enroll`,
-      null,
-      { headers: jsonHeaders(token) }
-    );
-
-    // 200 = enrolled OK, 409 = already enrolled (ทั้งคู่ถือว่าดี)
-    const ok = res.status === 200 || res.status === 409;
-    errorRate.add(!ok);
-    check(res, {
-      'enroll: enrolled or already enrolled': (r) => r.status === 200 || r.status === 409,
+  // ── Step 3+4: Setup — Load course และ open lesson (ทำครั้งเดียวต่อ VU) ─────
+  if (!vuSetupDone) {
+    group('3. Load Course Learning Page', () => {
+      const res = http.get(
+        `${BASE_URL}/api/students/courses/${COURSE_ID}/learn`,
+        { headers: jsonHeaders(vuToken) }
+      );
+      courseLearningTime.add(res.timings.duration);
+      errorRate.add(res.status !== 200);
+      check(res, { 'course learn: status 200': (r) => r.status === 200 });
     });
-  });
 
-  sleep(1);
+    sleep(1);
 
-  // ── Step 3: Load course learning page ─────────────────────────────────────
-  group('3. Load Course Learning Page', () => {
-    const res = http.get(
-      `${BASE_URL}/api/students/courses/${COURSE_ID}/learn`,
-      { headers: jsonHeaders(token) }
-    );
-
-    courseLearningTime.add(res.timings.duration);
-    const ok = res.status === 200;
-    errorRate.add(!ok);
-    check(res, {
-      'course learn: status 200': (r) => r.status === 200,
+    let videoUrl = null;
+    group('4. Open Lesson', () => {
+      const res = http.get(
+        `${BASE_URL}/api/students/courses/${COURSE_ID}/lessons/${LESSON_ID}`,
+        { headers: jsonHeaders(vuToken) }
+      );
+      lessonLoadTime.add(res.timings.duration);
+      errorRate.add(res.status !== 200);
+      check(res, { 'lesson: status 200': (r) => r.status === 200 });
+      if (res.status === 200) {
+        try { videoUrl = res.json('data.video_url'); } catch {}
+      }
     });
-  });
 
-  sleep(1);
+    // ── Step 4.5: Fetch video จาก MinIO ──────────────────────────────────────
+    if (videoUrl) {
+      group('4.5 Fetch Video from MinIO', () => {
+        const res = http.get(videoUrl, {
+          headers: { 'Range': 'bytes=0-1048575' }, // ขอแค่ 1MB แรก
+          timeout: '10s',
+        });
+        videoLoadTime.add(res.timings.duration);
+        const ok = res.status === 200 || res.status === 206;
+        errorRate.add(!ok);
+        check(res, {
+          'minio video: 200 or 206': (r) => r.status === 200 || r.status === 206,
+          'minio video: fast':       (r) => r.timings.duration < 3000,
+        });
+      });
+    } else {
+      console.log(`[VU ${__VU}] No video_url returned — skipping MinIO fetch`);
+    }
 
-  // ── Step 4: Open lesson (load video content) ───────────────────────────────
-  group('4. Open Lesson', () => {
-    const res = http.get(
-      `${BASE_URL}/api/students/courses/${COURSE_ID}/lessons/${LESSON_ID}`,
-      { headers: jsonHeaders(token) }
-    );
+    sleep(2); // รอ buffer เริ่มต้น
+    vuSetupDone = true;
+  }
 
-    lessonLoadTime.add(res.timings.duration);
-    const ok = res.status === 200;
-    errorRate.add(!ok);
-    check(res, {
-      'lesson: status 200': (r) => r.status === 200,
-    });
-  });
-
-  sleep(2); // รอ video buffer เล็กน้อย
-
-  // ── Step 5: Simulate watching — save progress ทุก PROGRESS_INTERVAL วิ ─────
-  // จำลองการดูวีดีโอ: progress เพิ่มขึ้นเรื่อยๆ จนถึง 95% (auto-complete threshold)
-  group('5. Watch Video (Save Progress)', () => {
-    const targetSeconds = Math.floor(VIDEO_DURATION_SECONDS * 0.95); // ดูถึง 95%
-    const steps = Math.ceil(targetSeconds / PROGRESS_INTERVAL_SECONDS); // จำนวนครั้งที่ save
-
-    // เพื่อไม่ให้ test นาน เกินไป จำกัดไว้ที่ 20 saves per VU iteration
-    const maxSaves = Math.min(steps, 20);
-
-    for (let i = 1; i <= maxSaves; i++) {
-      const currentSeconds = i * PROGRESS_INTERVAL_SECONDS;
+  // ── Step 5: Save Progress ทีละ tick (ต่อจากตำแหน่งเดิม) ────────────────────
+  // แต่ละ iteration ของ VU = ส่ง progress 1 ครั้ง แล้ว sleep ตาม interval จริง
+  if (!vuCompleted) {
+    vuProgress += PROGRESS_INTERVAL_SECONDS;
 
+    group('5. Watch Video (Save Progress)', () => {
       const res = http.post(
         `${BASE_URL}/api/students/lessons/${LESSON_ID}/progress`,
         JSON.stringify({
-          video_progress_seconds: currentSeconds,
+          video_progress_seconds: vuProgress,
           video_duration_seconds: VIDEO_DURATION_SECONDS,
         }),
-        { headers: jsonHeaders(token) }
+        { headers: jsonHeaders(vuToken) }
       );
 
       progressSaveTime.add(res.timings.duration);
@@ -201,32 +201,32 @@ export default function () {
         'progress save: fast':       (r) => r.timings.duration < 500,
       });
 
-      // รอ interval จริง (ย่อจาก 5s จริง เหลือ 1s เพื่อให้ test ไม่นานเกิน)
-      sleep(1);
-    }
-  });
-
-  // ── Step 6: Mark lesson complete ───────────────────────────────────────────
-  group('6. Complete Lesson', () => {
-    const res = http.post(
-      `${BASE_URL}/api/students/courses/${COURSE_ID}/lessons/${LESSON_ID}/complete`,
-      null,
-      { headers: jsonHeaders(token) }
-    );
-
-    completeLessonTime.add(res.timings.duration);
-    const ok = res.status === 200;
-
-    // 200 = completed now, อาจ 409 ถ้า already completed (ถือว่าโอเค)
-    errorRate.add(res.status !== 200 && res.status !== 409);
-    if (ok) completedCount.add(1);
-
-    check(res, {
-      'complete: status 200 or 409': (r) => r.status === 200 || r.status === 409,
+      console.log(`[VU ${__VU}] progress: ${vuProgress}s / ${VIDEO_DURATION_SECONDS}s (${Math.round(vuProgress / VIDEO_DURATION_SECONDS * 100)}%)`);
     });
-  });
 
-  sleep(1);
+    // ── Step 6: Mark complete เมื่อดูครบ ≥95% ──────────────────────────────
+    if (vuProgress >= VIDEO_DURATION_SECONDS * 0.95) {
+      group('6. Complete Lesson', () => {
+        const res = http.post(
+          `${BASE_URL}/api/students/courses/${COURSE_ID}/lessons/${LESSON_ID}/complete`,
+          null,
+          { headers: jsonHeaders(vuToken) }
+        );
+        completeLessonTime.add(res.timings.duration);
+        errorRate.add(res.status !== 200 && res.status !== 409);
+        if (res.status === 200) completedCount.add(1);
+        check(res, {
+          'complete: status 200 or 409': (r) => r.status === 200 || r.status === 409,
+        });
+      });
+
+      vuCompleted = true;
+      console.log(`[VU ${__VU}] ✓ Lesson completed`);
+    }
+  }
+
+  // sleep ตาม interval จริง — ทุก VU ส่ง progress ทุก PROGRESS_INTERVAL_SECONDS วินาที
+  sleep(PROGRESS_INTERVAL_SECONDS);
 }
 
 // ─── Summary ──────────────────────────────────────────────────────────────────
@@ -251,6 +251,7 @@ export function handleSummary(data) {
 ║  Login               : ${avg('login_duration')}ms / ${p95('login_duration')}ms${' '.repeat(Math.max(0, 20 - avg('login_duration').length - p95('login_duration').length))}║
 ║  Course Learning Page: ${avg('course_learning_duration')}ms / ${p95('course_learning_duration')}ms${' '.repeat(Math.max(0, 20 - avg('course_learning_duration').length - p95('course_learning_duration').length))}║
 ║  Lesson Load         : ${avg('lesson_load_duration')}ms / ${p95('lesson_load_duration')}ms${' '.repeat(Math.max(0, 20 - avg('lesson_load_duration').length - p95('lesson_load_duration').length))}║
+║  MinIO Video Fetch   : ${avg('video_load_duration')}ms / ${p95('video_load_duration')}ms${' '.repeat(Math.max(0, 20 - avg('video_load_duration').length - p95('video_load_duration').length))}║
 ║  Save Progress       : ${avg('progress_save_duration')}ms / ${p95('progress_save_duration')}ms${' '.repeat(Math.max(0, 20 - avg('progress_save_duration').length - p95('progress_save_duration').length))}║
 ║  Complete Lesson     : ${avg('complete_lesson_duration')}ms / ${p95('complete_lesson_duration')}ms${' '.repeat(Math.max(0, 20 - avg('complete_lesson_duration').length - p95('complete_lesson_duration').length))}║
 ╠══════════════════════════════════════════════════════════╣