FROM python:3.11-slim

# System deps
RUN apt-get update && apt-get install -y --no-install-recommends \
    curl \
    && rm -rf /var/lib/apt/lists/*

WORKDIR /app

# Install Python dependencies first (layer caching)
COPY requirements.txt .
RUN pip install --no-cache-dir -r requirements.txt

# Copy source
COPY . .

# Create __init__.py files if missing
RUN touch env/__init__.py graders/__init__.py server/__init__.py

# Expose port (HF Spaces uses 7860)
EXPOSE 7860

# Health check
HEALTHCHECK --interval=30s --timeout=10s --start-period=5s --retries=3 \
    CMD curl -f http://localhost:7860/ || exit 1

# Start FastAPI server
CMD ["uvicorn", "server.app:app", "--host", "0.0.0.0", "--port", "7860", "--workers", "1"]