feat: Implement lesson creation with file uploads (video, attachments) and quiz data, integrating MinIO for storage.

Backend/src/controllers/LessonsController.ts

@@ -0,0 +1,139 @@
+import { Request, Response, NextFunction } from 'express';
+import { ChaptersLessonService } from '../services/ChaptersLesson.service';
+import { ValidationError } from '../middleware/errorHandler';
+import {
+    lessonUpload,
+    LessonUploadRequest,
+    validateTotalAttachmentSize,
+    validateVideoSize
+} from '../middleware/upload';
+import { UploadedFileInfo, CreateLessonInput } from '../types/ChaptersLesson.typs';
+
+const chaptersLessonService = new ChaptersLessonService();
+
+/**
+ * Controller for handling lesson CRUD operations with file uploads
+ */
+export class LessonsController {
+    /**
+     * สร้างบทเรียนใหม่พร้อมไฟล์แนบ
+     * Create a new lesson with optional video and attachments
+     * 
+     * @route POST /api/instructors/courses/:courseId/chapters/:chapterId/lessons
+     * @contentType multipart/form-data
+     * 
+     * @param {number} courseId - รหัสคอร์ส / Course ID
+     * @param {number} chapterId - รหัสบท / Chapter ID
+     * @param {string} title - ชื่อบทเรียน (JSON: { th: "", en: "" })
+     * @param {string} [content] - เนื้อหาบทเรียน (JSON: { th: "", en: "" })
+     * @param {string} type - ประเภทบทเรียน (VIDEO | QUIZ)
+     * @param {number} [sort_order] - ลำดับการแสดงผล
+     * @param {File} [video] - ไฟล์วิดีโอ (สำหรับ type=VIDEO เท่านั้น)
+     * @param {File[]} [attachments] - ไฟล์แนบ (PDFs, เอกสาร, รูปภาพ)
+     */
+    async createLesson(req: LessonUploadRequest, res: Response, next: NextFunction): Promise<void> {
+        try {
+            const token = req.headers.authorization?.replace('Bearer ', '');
+            if (!token) {
+                throw new ValidationError('No token provided');
+            }
+
+            const courseId = parseInt(req.params.courseId, 10);
+            const chapterId = parseInt(req.params.chapterId, 10);
+
+            if (isNaN(courseId) || isNaN(chapterId)) {
+                throw new ValidationError('Invalid course ID or chapter ID');
+            }
+
+            // Parse JSON fields from multipart form
+            const title = JSON.parse(req.body.title || '{}');
+            const content = req.body.content ? JSON.parse(req.body.content) : undefined;
+            const type = req.body.type as 'VIDEO' | 'QUIZ';
+            const sortOrder = req.body.sort_order ? parseInt(req.body.sort_order, 10) : undefined;
+
+            if (!type || !['VIDEO', 'QUIZ'].includes(type)) {
+                throw new ValidationError('Invalid lesson type. Must be VIDEO or QUIZ');
+            }
+
+            if (!title.th || !title.en) {
+                throw new ValidationError('Title must have both Thai (th) and English (en) values');
+            }
+
+            // Process uploaded files
+            const files = req.files as { video?: Express.Multer.File[]; attachments?: Express.Multer.File[] } | undefined;
+
+            let video: UploadedFileInfo | undefined;
+            let attachments: UploadedFileInfo[] | undefined;
+
+            if (files?.video && files.video.length > 0) {
+                const videoFile = files.video[0];
+                validateVideoSize(videoFile);
+                video = {
+                    originalname: videoFile.originalname,
+                    mimetype: videoFile.mimetype,
+                    size: videoFile.size,
+                    buffer: videoFile.buffer,
+                };
+            }
+
+            if (files?.attachments && files.attachments.length > 0) {
+                validateTotalAttachmentSize(files.attachments);
+                attachments = files.attachments.map(file => ({
+                    originalname: file.originalname,
+                    mimetype: file.mimetype,
+                    size: file.size,
+                    buffer: file.buffer,
+                }));
+            }
+
+            // Validate VIDEO type must have video file (optional - can be uploaded later)
+            // if (type === 'VIDEO' && !video) {
+            //     throw new ValidationError('Video file is required for VIDEO type lessons');
+            // }
+
+            const input: CreateLessonInput = {
+                token,
+                course_id: courseId,
+                chapter_id: chapterId,
+                title,
+                content,
+                type,
+                sort_order: sortOrder,
+                video,
+                attachments,
+            };
+
+            const result = await chaptersLessonService.createLesson(input);
+            res.status(201).json(result);
+        } catch (error) {
+            next(error);
+        }
+    }
+}
+
+/**
+ * Express router middleware wrapper for file upload
+ * Use this in routes like:
+ * 
+ * router.post(
+ *     '/api/instructors/courses/:courseId/chapters/:chapterId/lessons',
+ *     authenticateMiddleware,
+ *     handleLessonUpload,
+ *     lessonsController.createLesson.bind(lessonsController)
+ * );
+ */
+export const handleLessonUpload = (req: Request, res: Response, next: NextFunction) => {
+    lessonUpload(req, res, (err) => {
+        if (err) {
+            return res.status(400).json({
+                error: {
+                    code: 'FILE_UPLOAD_ERROR',
+                    message: err.message,
+                }
+            });
+        }
+        next();
+    });
+};
+
+export const lessonsController = new LessonsController();