# CDN Integration

EasyStream supports multi-CDN video delivery for global reach, reduced latency, and bandwidth optimization.

## Supported CDN Providers

- 🐰 **BunnyCDN** - Cost-effective, global edge network
- ☁️ **Cloudflare R2** - Zero egress fees, S3-compatible
- 🪣 **AWS S3 + CloudFront** - Enterprise-grade, highly scalable
- 🔵 **Backblaze B2** - Affordable S3-compatible storage
- 🟢 **Wasabi** - Predictable pricing, no egress fees
- 🔧 **Custom** - Any S3-compatible storage provider

## Features

- 🌍 **Multi-CDN Support** - Upload to multiple providers for redundancy
- 📊 **Automatic Failover** - Falls back to secondary CDN if primary fails
- 🎬 **Multi-Quality Delivery** - Serve 360p, 480p, 720p, 1080p, 1440p, 2160p
- 💾 **Bandwidth Tracking** - Monitor usage and costs per provider
- 🔄 **Cache Purging** - Invalidate CDN cache on video updates
- 🚀 **Auto Quality Selection** - Pick best quality based on connection speed
- 💰 **Cost Optimization** - Use cheapest provider for your traffic patterns

## Setup

### 1. Database Migration

```bash
docker-compose exec db mysql -u easystream -peasystream easystream < __install/migrations/005_add_cdn_support.sql
```

### 2. Configure CDN Provider

Add your CDN provider credentials to the database:

```sql
INSERT INTO db_cdn_providers (
    provider_name, provider_type, api_key, storage_zone, 
    pull_zone, cdn_hostname, region, is_active, priority
) VALUES (
    'BunnyCDN Production', 'bunny', 'YOUR_API_KEY', 
    'easystream-videos', 'easystream', 'easystream.b-cdn.net', 
    'de', 1, 0
);
```

**Provider Types:**
- `bunny` - BunnyCDN
- `cloudflare` - Cloudflare R2
- `s3` - AWS S3
- `backblaze` - Backblaze B2
- `wasabi` - Wasabi
- `custom` - Custom S3-compatible

**Priority:** Lower = higher priority (0 is primary)

### 3. Add Frontend Assets

Include quality selector on video watch page:

```html
<link rel="stylesheet" href="/f_scripts/fe/css/quality-selector.css">
<script src="/f_scripts/fe/js/quality-selector.js"></script>
```

### 4. Upload Videos to CDN

```bash
# Upload single video
php app_scripts/cdn/upload_to_cdn.php 123

# Upload all pending videos
php app_scripts/cdn/upload_to_cdn.php --all
```

### 5. Automate Uploads (Optional)

Add to upload workflow in `upload.php`:

```php
require_once 'f_core/f_classes/class.cdn.php';
$cdn = new VCDN();

// After video upload
$cdn->uploadVideo($video_id, $local_file_path, 'original');
```

Or run background worker via supervisor/systemd.

## CDN Provider Configuration

### BunnyCDN

1. Sign up at [bunny.net](https://bunny.net)
2. Create a storage zone
3. Create a pull zone linked to the storage zone
4. Get your API key from Account Settings

```sql
INSERT INTO db_cdn_providers (
    provider_name, provider_type, api_key, storage_zone, 
    pull_zone, cdn_hostname
) VALUES (
    'BunnyCDN', 'bunny', 'YOUR_API_KEY', 
    'your-storage-zone', 'your-pull-zone', 'your-pull-zone.b-cdn.net'
);
```

**Cost:** ~$0.01/GB storage + $0.01-0.05/GB bandwidth (varies by region)

### Cloudflare R2

1. Sign up for Cloudflare account
2. Enable R2 in dashboard
3. Create a bucket
4. Generate API token

```sql
INSERT INTO db_cdn_providers (
    provider_name, provider_type, api_key, api_secret, 
    storage_zone, region
) VALUES (
    'Cloudflare R2', 'cloudflare', 'YOUR_ACCESS_KEY', 
    'YOUR_SECRET_KEY', 'your-bucket', 'auto'
);
```

**Cost:** $0.015/GB storage, **zero egress fees**

### AWS S3 + CloudFront

1. Create S3 bucket in AWS Console
2. Create CloudFront distribution
3. Generate IAM access keys

```sql
INSERT INTO db_cdn_providers (
    provider_name, provider_type, api_key, api_secret, 
    storage_zone, cdn_hostname, region
) VALUES (
    'AWS S3', 's3', 'YOUR_ACCESS_KEY', 'YOUR_SECRET_KEY', 
    'your-bucket', 'd123abc.cloudfront.net', 'us-east-1'
);
```

**Cost:** $0.023/GB storage + $0.085/GB bandwidth (first 10TB)

### Backblaze B2

1. Sign up at [backblaze.com](https://www.backblaze.com/b2)
2. Create a bucket
3. Generate application key

```sql
INSERT INTO db_cdn_providers (
    provider_name, provider_type, api_key, api_secret, 
    storage_zone, region
) VALUES (
    'Backblaze B2', 'backblaze', 'YOUR_KEY_ID', 'YOUR_APP_KEY', 
    'your-bucket', 'us-west-004'
);
```

**Cost:** $0.006/GB storage + $0.01/GB bandwidth (first 3x storage free)

### Wasabi

1. Sign up at [wasabi.com](https://wasabi.com)
2. Create a bucket
3. Generate access keys

```sql
INSERT INTO db_cdn_providers (
    provider_name, provider_type, api_key, api_secret, 
    storage_zone, region
) VALUES (
    'Wasabi', 'wasabi', 'YOUR_ACCESS_KEY', 'YOUR_SECRET_KEY', 
    'your-bucket', 'us-east-1'
);
```

**Cost:** $5.99/TB/month (storage + bandwidth included)

## Usage

### Get CDN URL

```http
GET /api/cdn.php?action=url&video_id=123&quality=720p
```

**Response:**
```json
{
  "success": true,
  "url": "https://easystream.b-cdn.net/videos/123/720p/video.mp4"
}
```

### Get Available Qualities

```http
GET /api/cdn.php?action=qualities&video_id=123
```

**Response:**
```json
{
  "success": true,
  "qualities": [
    {
      "quality_label": "auto",
      "resolution": "Auto",
      "cdn_url": null
    },
    {
      "quality_label": "1080p",
      "resolution": "1920x1080",
      "cdn_url": "https://easystream.b-cdn.net/videos/123/1080p/video.mp4"
    },
    {
      "quality_label": "720p",
      "resolution": "1280x720",
      "cdn_url": "https://easystream.b-cdn.net/videos/123/720p/video.mp4"
    }
  ]
}
```

### Upload to CDN

```http
POST /api/cdn.php?action=upload
Content-Type: application/json

{
  "video_id": 123,
  "local_path": "/srv/uploads/video.mp4",
  "quality": "original"
}
```

### Purge Cache

```http
POST /api/cdn.php?action=purge
Content-Type: application/json

{
  "video_id": 123
}
```

### Bandwidth Usage

```http
GET /api/cdn.php?action=bandwidth&days=30&provider_id=1
```

**Response:**
```json
{
  "success": true,
  "data": [
    {
      "date": "2026-03-01",
      "bandwidth_mb": 15234.56,
      "requests": 4567
    }
  ]
}
```

## Frontend Integration

### Quality Selector

The quality selector automatically initializes on video watch pages:

```javascript
const selector = new QualitySelector(videoId, {
    playerElement: document.querySelector('video'),
    containerElement: document.querySelector('.video-controls')
});
```

**Features:**
- Auto quality based on connection speed
- User preference persistence (localStorage)
- Seamless quality switching (preserves playback position)

### Programmatic Quality Switch

```javascript
const selector = window.qualitySelector;
selector.switchQuality('720p', 'https://cdn.example.com/video_720p.mp4');
```

## Multi-Quality Encoding

Generate multiple quality levels from source video:

```bash
# Using ffmpeg
ffmpeg -i input.mp4 \
  -vf scale=1920:1080 -c:v libx264 -b:v 5000k -preset medium output_1080p.mp4 \
  -vf scale=1280:720 -c:v libx264 -b:v 2500k -preset medium output_720p.mp4 \
  -vf scale=854:480 -c:v libx264 -b:v 1000k -preset medium output_480p.mp4 \
  -vf scale=640:360 -c:v libx264 -b:v 500k -preset medium output_360p.mp4
```

Then upload each quality:

```php
$qualities = ['1080p', '720p', '480p', '360p'];
foreach ($qualities as $quality) {
    $cdn->uploadVideo($video_id, "output_{$quality}.mp4", $quality);
}
```

## Bandwidth Tracking

Track CDN bandwidth usage automatically:

```php
$cdn->trackBandwidth($provider_id, $video_id, $bytes_transferred);
```

Integrate with analytics:

```php
// After video view
$file_size = filesize($video_path);
$cdn->trackBandwidth($provider_id, $video_id, $file_size);
```

## Cost Optimization

### Provider Selection Strategy

1. **High Traffic, US/EU audience:** BunnyCDN or Cloudflare R2
2. **Predictable costs:** Wasabi (flat rate)
3. **Low traffic, budget-conscious:** Backblaze B2
4. **Enterprise, existing AWS:** S3 + CloudFront

### Multi-Provider Setup

Configure multiple providers with priority:

```sql
-- Primary (lowest cost for your region)
INSERT INTO db_cdn_providers (..., priority) VALUES (..., 0);

-- Secondary (failover)
INSERT INTO db_cdn_providers (..., priority) VALUES (..., 1);
```

System automatically falls back to secondary if primary fails.

### Bandwidth Cost Estimates

| Provider | 1TB/month | 10TB/month | 100TB/month |
|----------|-----------|------------|-------------|
| BunnyCDN | $10-50 | $100-400 | $1,000-2,500 |
| Cloudflare R2 | $15 | $150 | $1,500 |
| AWS S3+CF | $85 | $815 | $6,815 |
| Backblaze B2 | $6 + $10 | $6 + $70 | $6 + $700 |
| Wasabi | $6 | $60 | $600 |

*Estimates vary by region and traffic patterns*

## Database Schema

### db_cdn_providers

| Column | Type | Description |
|--------|------|-------------|
| provider_id | INT | Primary key |
| provider_name | VARCHAR(50) | Display name |
| provider_type | ENUM | bunny/cloudflare/s3/backblaze/wasabi/custom |
| api_key | VARCHAR(255) | API key |
| api_secret | VARCHAR(255) | API secret (for S3-compatible) |
| storage_zone | VARCHAR(100) | Bucket/zone name |
| pull_zone | VARCHAR(100) | CDN distribution name |
| cdn_hostname | VARCHAR(255) | CDN URL hostname |
| region | VARCHAR(50) | Geographic region |
| is_active | TINYINT | Enabled status |
| priority | INT | Selection priority (lower = higher) |

### db_video_qualities

| Column | Type | Description |
|--------|------|-------------|
| quality_id | INT | Primary key |
| video_id | INT | Video ID |
| quality_label | VARCHAR(20) | 360p, 480p, 720p, 1080p, etc. |
| resolution | VARCHAR(20) | Width x height |
| bitrate | INT | Video bitrate (kbps) |
| file_path | VARCHAR(512) | Local file path |
| cdn_url | VARCHAR(512) | CDN URL |
| file_size | BIGINT | File size in bytes |
| codec | VARCHAR(50) | Video codec (h264, vp9, av1) |

### db_cdn_cache_status

| Column | Type | Description |
|--------|------|-------------|
| cache_id | INT | Primary key |
| video_id | INT | Video ID |
| provider_id | INT | CDN provider ID |
| quality_label | VARCHAR(20) | Quality level |
| cdn_url | VARCHAR(512) | CDN URL |
| status | ENUM | pending/uploading/ready/failed |
| upload_progress | INT | Upload progress (%) |
| error_message | TEXT | Error details |

## Performance

- **CDN latency:** 10-50ms (vs 200-500ms local)
- **Upload speed:** Varies by provider (10-100 MB/s typical)
- **Cache hit ratio:** 85-95% (after warmup)
- **Failover time:** <1 second (automatic)

## Troubleshooting

### Upload fails with "Permission denied"

1. Check API credentials are correct
2. Verify storage zone/bucket exists
3. Check firewall allows outbound HTTPS

### Video URL returns 404

1. Check CDN cache status: `SELECT * FROM db_cdn_cache_status WHERE video_id = X`
2. Verify file uploaded successfully to CDN
3. Check CDN hostname is correct

### Quality selector doesn't appear

1. Verify JavaScript is loaded
2. Check browser console for errors
3. Ensure video has multiple qualities available

### Bandwidth tracking inaccurate

1. Check analytics integration is active
2. Verify `trackBandwidth()` called on video views
3. Review CDN provider's own bandwidth reports

## Advanced Features

### Adaptive Bitrate Streaming (HLS/DASH)

Generate HLS playlist for adaptive streaming:

```bash
ffmpeg -i input.mp4 \
  -vf scale=1920:1080 -c:v libx264 -b:v 5000k -f hls -hls_time 6 -hls_list_size 0 output_1080p.m3u8 \
  -vf scale=1280:720 -c:v libx264 -b:v 2500k -f hls -hls_time 6 -hls_list_size 0 output_720p.m3u8
```

### Geo-Routing

Route users to nearest CDN edge:

```php
$user_country = $_SERVER['HTTP_CF_IPCOUNTRY'] ?? 'US';
$cdn_region = $user_country === 'US' ? 'us-east' : 'eu-west';

// Select provider by region
$provider = getProviderByRegion($cdn_region);
```

### Signed URLs (Hotlink Protection)

Generate time-limited signed URLs:

```php
function generateSignedUrl($url, $expiry = 3600) {
    $secret = 'YOUR_SIGNING_SECRET';
    $expires = time() + $expiry;
    $token = hash_hmac('sha256', $url . $expires, $secret);
    
    return "{$url}?token={$token}&expires={$expires}";
}
```

## Future Enhancements

- [ ] Automatic quality encoding on upload
- [ ] HLS/DASH adaptive streaming
- [ ] Geo-routing based on user location
- [ ] Signed URLs for DRM/hotlink protection
- [ ] CDN analytics dashboard
- [ ] Cost alerts (bandwidth thresholds)
- [ ] Video preview thumbnails (storyboards)
- [ ] AV1 codec support
- [ ] CDN warmup on publish
- [ ] Multi-region redundancy

## Learn More

- [BunnyCDN Documentation](https://docs.bunny.net/)
- [Cloudflare R2 Docs](https://developers.cloudflare.com/r2/)
- [AWS S3 Best Practices](https://docs.aws.amazon.com/AmazonS3/latest/userguide/best-practices.html)
- [FFmpeg Encoding Guide](https://trac.ffmpeg.org/wiki/Encode/H.264)