feat: Allow instructors to set rejected courses to draft and explicitly set course status to rejected upon administrative rejection.

Backend/src/controllers/CoursesInstructorController.ts

@@ -21,6 +21,7 @@ import {
     GetQuizAttemptDetailResponse,
     GetEnrolledStudentDetailResponse,
     GetCourseApprovalHistoryResponse,
+    setCourseDraftResponse,
 } from '../types/CoursesInstructor.types';
 import { CreateCourseValidator } from "../validators/CoursesInstructor.validator";
 
@@ -189,6 +190,22 @@ export class CoursesInstructorController {
         return await CoursesInstructorService.sendCourseForReview({ token, course_id: courseId });
     }
 
+    /**
+     * ตั้งค่าคอร์สเป็น DRAFT
+     * Set course to draft
+     * @param courseId - รหัสคอร์ส / Course ID
+     */
+    @Post('set-draft/{courseId}')
+    @Security('jwt', ['instructor'])
+    @SuccessResponse('200', 'Course set to draft successfully')
+    @Response('401', 'Invalid or expired token')
+    @Response('404', 'Course not found')
+    public async setCourseDraft(@Request() request: any, @Path() courseId: number): Promise<setCourseDraftResponse> {
+        const token = request.headers.authorization?.replace('Bearer ', '');
+        if (!token) throw new ValidationError('No token provided')
+        return await CoursesInstructorService.setCourseDraft({ token, course_id: courseId });
+    }
+
     /**
      * ดึงประวัติการส่งอนุมัติคอร์สทั้งหมด
      * Get all course approval history