# Production Deployment Guide

This guide explains how to build and deploy the Orbital Simulator in production environments.

## Building for Production

### 1. Rust API Server

Build the optimized API server:

```bash
# Build without GUI dependencies (recommended for servers)
cargo build --release --bin api_server --no-default-features

# Or build with GUI support (if system libraries are available)
cargo build --release --bin api_server --features gui
```

The compiled binary will be at `target/release/api_server`.

### 2. Web Frontend

Build the optimized web frontend:

```bash
cd web
npm install
npm run build
```

The built files will be in `web/dist/`.

### 3. Desktop GUI (Optional)

Build the desktop application:

```bash
# Install Tauri CLI if not already installed
cargo install tauri-cli

# Build the desktop app
cargo tauri build --features gui
```

The built application will be in `src-tauri/target/release/bundle/`.

## Deployment Options

### Option 1: Single Server Deployment

Deploy both API and web frontend on the same server:

```bash
# 1. Copy the API server binary
cp target/release/api_server /opt/orbital_simulator/

# 2. Copy the web files
cp -r web/dist /opt/orbital_simulator/static

# 3. Create systemd service
sudo tee /etc/systemd/system/orbital-simulator.service > /dev/null <<EOF
[Unit]
Description=Orbital Simulator API Server
After=network.target

[Service]
Type=simple
User=orbital
WorkingDirectory=/opt/orbital_simulator
ExecStart=/opt/orbital_simulator/api_server
Restart=always
RestartSec=10
Environment=STATIC_DIR=/opt/orbital_simulator/static

[Install]
WantedBy=multi-user.target
EOF

# 4. Start the service
sudo systemctl enable orbital-simulator
sudo systemctl start orbital-simulator
```

### Option 2: Separate API and Web Servers

#### API Server (Backend)

```bash
# Deploy API server only
cp target/release/api_server /opt/orbital_simulator/
```

Configure reverse proxy (nginx example):

```nginx
server {
    listen 80;
    server_name api.yourdomain.com;

    location / {
        proxy_pass http://localhost:4395;
        proxy_set_header Host $host;
        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_set_header X-Forwarded-Proto $scheme;
    }
}
```

#### Web Frontend (Static Hosting)

Deploy `web/dist/` to any static hosting service:

- **Nginx**: Copy files to web root
- **Apache**: Copy files to document root  
- **CDN**: Upload to AWS S3, Cloudflare, etc.

Update the API endpoint in the frontend if needed.

### Option 3: Docker Deployment

Create `Dockerfile`:

```dockerfile
# Multi-stage build
FROM rust:1.70 as rust-builder
WORKDIR /app
COPY Cargo.toml Cargo.lock ./
COPY src ./src
COPY build.rs ./
RUN cargo build --release --bin api_server --no-default-features

FROM node:18 as web-builder
WORKDIR /app
COPY web/package*.json ./
RUN npm install
COPY web ./
RUN npm run build

FROM debian:bookworm-slim
RUN apt-get update && apt-get install -y ca-certificates && rm -rf /var/lib/apt/lists/*
WORKDIR /app
COPY --from=rust-builder /app/target/release/api_server ./
COPY --from=web-builder /app/dist ./static
EXPOSE 4395
CMD ["./api_server"]
```

Build and run:

```bash
docker build -t orbital-simulator .
docker run -p 4395:4395 orbital-simulator
```

## Configuration

### Environment Variables

- `PORT`: Server port (default: 4395)
- `HOST`: Server host (default: 0.0.0.0)
- `STATIC_DIR`: Directory for static files (default: web/dist)
- `LOG_LEVEL`: Logging level (debug, info, warn, error)
- `MAX_SIMULATIONS`: Maximum concurrent simulations (default: 10)

### Example Production Configuration

```bash
export PORT=8080
export HOST=0.0.0.0
export LOG_LEVEL=info
export MAX_SIMULATIONS=50
export STATIC_DIR=/var/www/orbital-simulator
```

## Performance Tuning

### Rust API Server

1. **Enable release optimizations** in `Cargo.toml`:
   ```toml
   [profile.release]
   opt-level = 3
   lto = true
   codegen-units = 1
   panic = 'abort'
   ```

2. **Limit concurrent simulations** to prevent resource exhaustion

3. **Use connection pooling** for database connections (if added)

### Web Frontend

1. **Enable gzip compression** in your web server
2. **Set appropriate cache headers** for static assets
3. **Use a CDN** for global distribution
4. **Implement lazy loading** for large datasets

## Monitoring and Logging

### Metrics to Monitor

- API response times
- Active simulation count  
- Memory usage
- CPU usage
- WebSocket connection count

### Logging

The application uses the `log` crate. Configure logging level:

```bash
RUST_LOG=info ./api_server
```

Log levels:
- `debug`: Detailed debugging information
- `info`: General operational information  
- `warn`: Warning messages
- `error`: Error messages only

### Health Checks

The API server provides health check endpoints:

- `GET /api/health`: Basic health check
- `GET /api/metrics`: System metrics (if enabled)

## Security Considerations

1. **Use HTTPS** in production
2. **Configure CORS** appropriately for your domain
3. **Implement rate limiting** to prevent abuse
4. **Sanitize user inputs** in configuration uploads
5. **Run with minimal privileges** (non-root user)
6. **Keep dependencies updated** regularly

## Backup and Recovery

### Data to Backup

- Configuration files
- Simulation results (if persisted)
- User data (if user accounts are added)

### Recovery Procedures

1. Restore application binary
2. Restore configuration files
3. Restart services
4. Verify functionality

## Scaling

### Horizontal Scaling

- Deploy multiple API server instances behind a load balancer
- Use Redis for session storage (if sessions are added)
- Implement proper service discovery

### Vertical Scaling

- Increase server resources (CPU, RAM)
- Optimize simulation algorithms
- Use faster storage (SSD)

## Troubleshooting

### Common Issues

1. **Port already in use**: Change PORT environment variable
2. **Static files not found**: Check STATIC_DIR path
3. **High memory usage**: Limit concurrent simulations
4. **Slow performance**: Enable release optimizations

### Debug Mode

Run with debug logging:

```bash
RUST_LOG=debug ./api_server
```

### Performance Profiling

Use `perf` or `valgrind` to profile the application:

```bash
perf record --call-graph=dwarf ./api_server
perf report
```

## Support

For issues and questions:

1. Check the logs for error messages
2. Verify configuration settings
3. Test with minimal configuration
4. Consult the main README.md for additional information