feat: implement course cloning functionality including chapters, lessons, quizzes, and attachments for instructors.

Backend/src/controllers/CoursesInstructorController.ts

@@ -23,6 +23,7 @@ import {
     GetEnrolledStudentDetailResponse,
     GetCourseApprovalHistoryResponse,
     setCourseDraftResponse,
+    CloneCourseResponse,
 } from '../types/CoursesInstructor.types';
 import { CreateCourseValidator } from "../validators/CoursesInstructor.validator";
 
@@ -178,6 +179,33 @@ export class CoursesInstructorController {
         return await CoursesInstructorService.deleteCourse(token, courseId);
     }
 
+    /**
+     * คัดลอกคอร์ส (Clone Course)
+     * Clone an existing course to a new one with copied chapters, lessons, quizzes, and attachments
+     * @param courseId - รหัสคอร์สต้นฉบับ / Source Course ID
+     * @param body - ชื่อคอร์สใหม่ / New course title
+     */
+    @Post('{courseId}/clone')
+    @Security('jwt', ['instructor'])
+    @SuccessResponse('201', 'Course cloned successfully')
+    @Response('401', 'Invalid or expired token')
+    @Response('403', 'Not an instructor of this course')
+    @Response('404', 'Course not found')
+    public async cloneCourse(
+        @Request() request: any,
+        @Path() courseId: number,
+        @Body() body: { title: { th: string; en: string } }
+    ): Promise<CloneCourseResponse> {
+        const token = request.headers.authorization?.replace('Bearer ', '');
+        if (!token) throw new ValidationError('No token provided');
+
+        return await CoursesInstructorService.cloneCourse({
+            token,
+            course_id: courseId,
+            title: body.title
+        });
+    }
+
     /**
      * ส่งคอร์สเพื่อขออนุมัติจากแอดมิน
      * Submit course for admin review and approval