# Hugging Face Spaces Deployment Guide

## ✅ Changes Made for Hugging Face Spaces Compatibility

### 1. Port Configuration
- **Updated `backend/app.py`**: Server now reads `PORT` from environment variable (default: 7860)
  ```python
  port = int(os.environ.get("PORT", 7860))
  uvicorn.run(app, host="0.0.0.0", port=port)
  ```
- **Updated `Dockerfile`**: CMD uses `${PORT:-7860}` for dynamic port binding

### 2. Filesystem Permissions
- **Changed output directory**: `OUTPUT_DIR` now uses `/tmp/outputs` instead of `./outputs`
  - Hugging Face Spaces containers have read-only `/app` directory
  - `/tmp` is writable for temporary files
  - **Note**: Files in `/tmp` are ephemeral and lost on restart

### 3. Static File Serving
- **Fixed sample image serving**: Mounted `/cyto`, `/colpo`, `/histo` directories from `frontend/dist`
- **Added catch-all route**: Serves static files (logos, banners) from dist root
- **Frontend dist path fallback**: Checks both `./frontend/dist` (Docker) and `../frontend/dist` (local dev)

### 4. Frontend Configuration
- **Frontend already configured**: Uses `window.location.origin` in production, so API calls work on any domain
- **Vite build**: Copies `public/` contents to `dist/` automatically

---

## 📋 Deployment Checklist

### Step 1: Create Hugging Face Space
1. Go to https://huggingface.co/spaces
2. Click **"Create new Space"**
3. Choose:
   - **Space SDK**: Docker
   - **Hardware**: CPU Basic (free) or GPU (for faster inference)
   - **Visibility**: Public or Private

### Step 2: Set Up Git LFS (for large model files)
Your project has large model files (`.pt`, `.pth`, `.keras`). Track them with Git LFS:

```bash
# Install Git LFS if not already installed
git lfs install

# Track model files
git lfs track "*.pt"
git lfs track "*.pth"
git lfs track "*.keras"
git lfs track "*.pkl"

# Commit .gitattributes
git add .gitattributes
git commit -m "Track model files with Git LFS"
```

### Step 3: Configure Secrets (Optional)
If you want AI-generated summaries using Mistral, add a secret:

1. Go to Space Settings → Variables and secrets
2. Add new secret:
   - Name: `HF_TOKEN`
   - Value: Your Hugging Face token (from https://huggingface.co/settings/tokens)

### Step 4: Push Code to Space
```bash
# Add Space as remote
git remote add space https://huggingface.co/spaces/<YOUR_USERNAME>/<SPACE_NAME>

# Push to Space
git push space main
```

### Step 5: Monitor Build
- Hugging Face will build the Docker image (this may take 10-20 minutes)
- Watch logs in the Space's "Logs" tab
- Once built, the Space will automatically start

---

## 🔍 Troubleshooting

### Build Issues

**Problem**: Docker build times out or fails
- **Solution**: Reduce image size by pinning lighter dependencies in `requirements.txt`
- **Solution**: Consider using pre-built wheels for TensorFlow/PyTorch

**Problem**: Model files not found
- **Solution**: Ensure Git LFS is configured and model files are committed
- **Solution**: Check that model paths in `backend/app.py` match actual filenames

### Runtime Issues

**Problem**: 404 errors for sample images
- **Solution**: Rebuild frontend: `cd frontend && npm run build`
- **Solution**: Verify `frontend/public/` contents are copied to `dist/`

**Problem**: Permission denied errors
- **Solution**: All writes should go to `/tmp/outputs` (already fixed)
- **Solution**: Never write to `/app` directory

**Problem**: Port binding errors
- **Solution**: Use `$PORT` env var (already configured in Dockerfile and app.py)

### Performance Issues

**Problem**: Slow startup or inference
- **Solution**: Models load at startup; consider lazy loading on first request
- **Solution**: Upgrade to GPU hardware tier for faster inference
- **Solution**: Add caching for model weights

---

## 📁 File Structure Expected in Space

```
/app/
├── app.py                              # Main FastAPI app
├── model.py, model_histo.py, etc.     # Model definitions
├── augmentations.py                    # Image preprocessing
├── requirements.txt                    # Python dependencies
├── best2.pt                           # YOLO cytology model
├── MWTclass2.pth                      # MWT classifier
├── yolo_colposcopy.pt                 # YOLO colposcopy model
├── histopathology_trained_model.keras # Histopathology model
├── logistic_regression_model.pkl      # CIN classifier (optional)
└── frontend/
    └── dist/                          # Built frontend
        ├── index.html
        ├── assets/                    # JS/CSS bundles
        ├── cyto/                      # Sample cytology images
        ├── colpo/                     # Sample colposcopy images
        ├── histo/                     # Sample histopathology images
        └── *.png, *.jpeg              # Logos, banners
```

---

## 🌐 Access Your Space

Once deployed, your app will be available at:
```
https://huggingface.co/spaces/<YOUR_USERNAME>/<SPACE_NAME>
```

The frontend serves at `/` and the API is accessible at:
- `POST /predict/` - Run model inference
- `POST /reports/` - Generate medical reports
- `GET /health` - Health check
- `GET /models` - List available models

---

## ⚠️ Important Notes

### Ephemeral Storage
- Files in `/tmp/outputs` are **lost on restart**
- For persistent reports, consider:
  - Downloading immediately after generation
  - Uploading to external storage (S3, Hugging Face Datasets)
  - Using Persistent Storage (requires paid tier)

### Model Loading Time
- All models load at startup (~30-60 seconds)
- First request after restart may be slower
- Consider implementing health check endpoint that waits for models

### Resource Limits
- Free CPU tier: Limited RAM and CPU
- Models are memory-intensive (TensorFlow + PyTorch + YOLO)
- May need **CPU Upgrade** or **GPU** tier for production use

### CORS
- Currently allows all origins (`allow_origins=["*"]`)
- For production, restrict to your Space domain

---

## 🚀 Next Steps After Deployment

1. **Test all three models**:
   - Upload cytology sample → Test YOLO detection
   - Upload colposcopy sample → Test CIN classification
   - Upload histopathology sample → Test breast cancer classification

2. **Generate a test report**:
   - Run an analysis
   - Fill out patient metadata
   - Generate HTML/PDF report
   - Verify download links work

3. **Monitor performance**:
   - Check inference times
   - Monitor memory usage in Space logs
   - Consider upgrading hardware if needed

4. **Share your Space**:
   - Add a README with usage instructions
   - Include sample images in the repo
   - Add citations for model papers

---

## 📞 Support

If you encounter issues:
1. Check Space logs: Settings → Logs
2. Verify all model files are present: Settings → Files
3. Test locally with Docker: `docker build -t pathora . && docker run -p 7860:7860 pathora`
4. Open an issue on Hugging Face Discuss: https://discuss.huggingface.co/

---

**Deployment ready! 🎉**