feat: add certificate generation system with PDF template and Thai font support

Backend/src/controllers/CertificateController.ts

@@ -0,0 +1,61 @@
+import { Get, Post, Route, Tags, SuccessResponse, Response, Security, Path, Request } from 'tsoa';
+import { ValidationError } from '../middleware/errorHandler';
+import { CertificateService } from '../services/certificate.service';
+import {
+    GenerateCertificateResponse,
+    GetCertificateResponse,
+    ListMyCertificatesResponse,
+} from '../types/certificate.types';
+
+@Route('api/certificates')
+@Tags('Certificates')
+export class CertificateController {
+    private certificateService = new CertificateService();
+
+    /**
+     * ดึงรายการใบ Certificate ทั้งหมดของผู้ใช้
+     * Get all certificates for the authenticated user
+     */
+    @Get('')
+    @Security('jwt')
+    @SuccessResponse('200', 'Certificates retrieved successfully')
+    @Response('401', 'Invalid or expired token')
+    public async listMyCertificates(@Request() request: any): Promise<ListMyCertificatesResponse> {
+        const token = request.headers.authorization?.replace('Bearer ', '');
+        if (!token) throw new ValidationError('No token provided');
+        return await this.certificateService.listMyCertificates({ token });
+    }
+
+    /**
+     * ดึงใบ Certificate ของคอร์สที่ระบุ
+     * Get certificate for a specific course
+     * @param courseId - รหัสคอร์ส / Course ID
+     */
+    @Get('{courseId}')
+    @Security('jwt')
+    @SuccessResponse('200', 'Certificate retrieved successfully')
+    @Response('401', 'Invalid or expired token')
+    @Response('404', 'Certificate not found')
+    public async getCertificate(@Request() request: any, @Path() courseId: number): Promise<GetCertificateResponse> {
+        const token = request.headers.authorization?.replace('Bearer ', '');
+        if (!token) throw new ValidationError('No token provided');
+        return await this.certificateService.getCertificate({ token, course_id: courseId });
+    }
+
+    /**
+     * สร้างใบ Certificate สำหรับคอร์สที่เรียนจบแล้ว
+     * Generate certificate for a completed course
+     * @param courseId - รหัสคอร์ส / Course ID
+     */
+    @Post('{courseId}/generate')
+    @Security('jwt')
+    @SuccessResponse('201', 'Certificate generated successfully')
+    @Response('400', 'Course not completed or does not offer certificates')
+    @Response('401', 'Invalid or expired token')
+    @Response('404', 'Enrollment not found')
+    public async generateCertificate(@Request() request: any, @Path() courseId: number): Promise<GenerateCertificateResponse> {
+        const token = request.headers.authorization?.replace('Bearer ', '');
+        if (!token) throw new ValidationError('No token provided');
+        return await this.certificateService.generateCertificate({ token, course_id: courseId });
+    }
+}