# Create Lesson with Files - Simplified API

## 📝 Create Lesson (One Request)

### POST `/instructor/courses/:courseId/chapters/:chapterId/lessons`

สร้าง lesson พร้อม video และ attachments ในครั้งเดียว

---

## Request Examples

### 1. Text Lesson (No Files)

```http
POST /api/instructor/courses/1/chapters/1/lessons
Authorization: Bearer <token>
Content-Type: application/json

{
  "title": {
    "th": "บทที่ 1: แนะนำ",
    "en": "Lesson 1: Introduction"
  },
  "content": {
    "th": "<p>เนื้อหาบทเรียน...</p>",
    "en": "<p>Lesson content...</p>"
  },
  "type": "text",
  "sort_order": 1,
  "is_sequential": true
}
```

---

### 2. Video Lesson (Video Only)

```http
POST /api/instructor/courses/1/chapters/1/lessons
Authorization: Bearer <token>
Content-Type: multipart/form-data

title_th: "บทที่ 1: แนะนำ Python"
title_en: "Lesson 1: Introduction to Python"
content_th: "<p>Python เป็นภาษา...</p>"
content_en: "<p>Python is a...</p>"
type: "video"
sort_order: 1
video: <lesson-video.mp4>
```

**Response 201**:
```json
{
  "id": 1,
  "chapter_id": 1,
  "title": {
    "th": "บทที่ 1: แนะนำ Python",
    "en": "Lesson 1: Introduction to Python"
  },
  "type": "video",
  "video": {
    "url": "https://cdn.example.com/videos/lesson-1.m3u8",
    "duration": "00:15:30",
    "file_size": 52428800
  },
  "attachments": [],
  "created_at": "2024-12-23T15:00:00Z"
}
```

---

### 3. Video + Attachments (Complete)

```http
POST /api/instructor/courses/1/chapters/1/lessons
Authorization: Bearer <token>
Content-Type: multipart/form-data

# Lesson Info
title_th: "บทที่ 1: แนะนำ Python"
title_en: "Lesson 1: Introduction to Python"
content_th: "<p>Python เป็นภาษา...</p>"
content_en: "<p>Python is a...</p>"
type: "video"
sort_order: 1
is_sequential: true

# Video
video: <lesson-video.mp4>

# Attachments
attachments[]: <slides.pdf>
attachments[]: <code.zip>
attachments[]: <exercises.docx>

# Attachment Descriptions
descriptions[0][th]: "สไลด์ประกอบการสอน"
descriptions[0][en]: "Lecture slides"
descriptions[1][th]: "โค้ดตัวอย่าง"
descriptions[1][en]: "Sample code"
descriptions[2][th]: "แบบฝึกหัด"
descriptions[2][en]: "Exercises"
```

**Response 201**:
```json
{
  "id": 1,
  "chapter_id": 1,
  "title": {
    "th": "บทที่ 1: แนะนำ Python",
    "en": "Lesson 1: Introduction to Python"
  },
  "content": {
    "th": "<p>Python เป็นภาษา...</p>",
    "en": "<p>Python is a...</p>"
  },
  "type": "video",
  "sort_order": 1,
  "is_sequential": true,
  
  "video": {
    "url": "https://cdn.example.com/videos/lesson-1.m3u8",
    "duration": "00:15:30",
    "file_size": 52428800,
    "uploaded_at": "2024-12-23T15:00:00Z"
  },
  
  "attachments": [
    {
      "id": 1,
      "file_name": "slides.pdf",
      "file_size": 2048576,
      "mime_type": "application/pdf",
      "description": {
        "th": "สไลด์ประกอบการสอน",
        "en": "Lecture slides"
      },
      "sort_order": 1,
      "download_url": "/api/lessons/1/attachments/1/download"
    },
    {
      "id": 2,
      "file_name": "code.zip",
      "file_size": 512000,
      "mime_type": "application/zip",
      "description": {
        "th": "โค้ดตัวอย่าง",
        "en": "Sample code"
      },
      "sort_order": 2,
      "download_url": "/api/lessons/1/attachments/2/download"
    },
    {
      "id": 3,
      "file_name": "exercises.docx",
      "file_size": 256000,
      "mime_type": "application/vnd.openxmlformats-officedocument.wordprocessingml.document",
      "description": {
        "th": "แบบฝึกหัด",
        "en": "Exercises"
      },
      "sort_order": 3,
      "download_url": "/api/lessons/1/attachments/3/download"
    }
  ],
  
  "created_at": "2024-12-23T15:00:00Z"
}
```

---

### 4. PDF Lesson (Attachments Only)

```http
POST /api/instructor/courses/1/chapters/1/lessons
Authorization: Bearer <token>
Content-Type: multipart/form-data

title_th: "บทที่ 2: เอกสารประกอบ"
title_en: "Lesson 2: Reading Materials"
type: "pdf"
sort_order: 2

attachments[]: <main-document.pdf>
attachments[]: <supplementary.pdf>

descriptions[0][th]: "เอกสารหลัก"
descriptions[0][en]: "Main document"
descriptions[1][th]: "เอกสารเพิ่มเติม"
descriptions[1][en]: "Supplementary material"
```

---

## Add More Files Later

ถ้าต้องการเพิ่มไฟล์ทีหลัง:

### POST `/instructor/courses/:courseId/lessons/:lessonId/attachments`

```http
POST /api/instructor/courses/1/lessons/1/attachments
Authorization: Bearer <token>
Content-Type: multipart/form-data

attachments[]: <additional-file.pdf>
descriptions[0][th]: "ไฟล์เพิ่มเติม"
descriptions[0][en]: "Additional file"
```

---

## Frontend Example

```javascript
async function createLesson(courseId, chapterId, lessonData) {
  const formData = new FormData();
  
  // Basic info
  formData.append('title_th', lessonData.title.th);
  formData.append('title_en', lessonData.title.en);
  formData.append('content_th', lessonData.content.th);
  formData.append('content_en', lessonData.content.en);
  formData.append('type', lessonData.type);
  formData.append('sort_order', lessonData.sortOrder);
  
  // Video (if exists)
  if (lessonData.video) {
    formData.append('video', lessonData.video);
  }
  
  // Attachments (if exists)
  if (lessonData.attachments && lessonData.attachments.length > 0) {
    lessonData.attachments.forEach((file, index) => {
      formData.append('attachments[]', file.file);
      formData.append(`descriptions[${index}][th]`, file.description.th);
      formData.append(`descriptions[${index}][en]`, file.description.en);
    });
  }
  
  const response = await fetch(
    `/api/instructor/courses/${courseId}/chapters/${chapterId}/lessons`,
    {
      method: 'POST',
      headers: {
        'Authorization': `Bearer ${token}`
      },
      body: formData
    }
  );
  
  return await response.json();
}

// Usage
const lesson = await createLesson(1, 1, {
  title: {
    th: 'บทที่ 1: แนะนำ',
    en: 'Lesson 1: Introduction'
  },
  content: {
    th: '<p>เนื้อหา...</p>',
    en: '<p>Content...</p>'
  },
  type: 'video',
  sortOrder: 1,
  video: videoFile,
  attachments: [
    {
      file: pdfFile,
      description: { th: 'สไลด์', en: 'Slides' }
    },
    {
      file: zipFile,
      description: { th: 'โค้ด', en: 'Code' }
    }
  ]
});
```

---

## Benefits

✅ **One Request** - ส่งครั้งเดียว ไม่ต้องส่งหลายรอบ  
✅ **Atomic** - สร้างสำเร็จหรือ fail ทั้งหมด  
✅ **Faster** - ลด HTTP requests  
✅ **Better UX** - Instructor ไม่ต้องรอหลายขั้นตอน  
✅ **Flexible** - เพิ่มไฟล์ทีหลังได้

---

## Summary

**Before**: 3 requests
1. Create lesson
2. Upload video
3. Upload attachments

**After**: 1 request
1. Create lesson with everything ✨
