FROM python:3.11-slim

# Prevent Python from buffering stdout/stderr and creating .pyc files
ENV PYTHONDONTWRITEBYTECODE=1 \
    PYTHONUNBUFFERED=1 \
    DEBIAN_FRONTEND=noninteractive

# Set working directory
WORKDIR /app

# Install system runtime dependencies required for OpenCV and image processing
RUN apt-get update && apt-get install -y --no-install-recommends \
    build-essential \
    libgl1 \
    libglib2.0-0 \
    libgomp1 \
    curl \
    && rm -rf /var/lib/apt/lists/*

# Copy and install python dependencies
COPY requirements.txt .
RUN pip install --no-cache-dir --upgrade pip && \
    pip install --no-cache-dir -r requirements.txt

# Pre-create storage, exports, and models directories
RUN mkdir -p /app/storage/models /app/storage/classroom_photos /app/storage/students /app/exports

# Pre-download OpenCV ONNX models during build so the container starts immediately without network delay
RUN curl -fsSL -o /app/storage/models/face_detection_yunet_2023mar.onnx \
    https://github.com/opencv/opencv_zoo/raw/main/models/face_detection_yunet/face_detection_yunet_2023mar.onnx && \
    curl -fsSL -o /app/storage/models/face_recognition_sface_2021dec.onnx \
    https://github.com/opencv/opencv_zoo/raw/main/models/face_recognition_sface/face_recognition_sface_2021dec.onnx

# Copy application source code
COPY . .

# Expose default Hugging Face Spaces port
EXPOSE 7860

# Health check to ensure service is responding
HEALTHCHECK --interval=30s --timeout=10s --start-period=15s --retries=3 \
    CMD curl -f http://localhost:7860/api/health || exit 1

CMD ["python", "app.py"]