FROM python:3.11-slim

# Install system dependencies, headless LibreOffice, and common fonts
RUN apt-get update && apt-get install -y --no-install-recommends \
    libreoffice-writer \
    libreoffice-calc \
    libreoffice-impress \
    libreoffice-java-common \
    python3-uno \
    fonts-liberation \
    fonts-dejavu \
    procps \
    && rm -rf /var/lib/apt/lists/*

# Set up a non-root user for Hugging Face Spaces compliance
RUN useradd -m -u 1000 user
USER user
ENV HOME=/home/user \
    PATH=/home/user/.local/bin:$PATH

# Map the system UNO python packages into our pythonpath runtime environment
ENV PYTHONPATH=/usr/lib/python3/dist-packages:$PYTHONPATH

WORKDIR /app

# Install Python requirements
COPY --chown=user requirements.txt .
RUN pip install --no-cache-dir --user -r requirements.txt

# Copy backend application
COPY --chown=user app.py .

# Pre-build workspace folders
RUN mkdir -p /home/user/uploads /home/user/outputs

# Hugging Face default application interface port
EXPOSE 7860

# We run the unoserver background listener explicitly using python3 to avoid binary mismatches, 
# and use an ampersand (&) instead of --daemon so it logs errors properly if it fails.
# We explicitly separate the listener port (2002) and the internal LibreOffice control port (2003)
CMD ["bash", "-c", "python3 -m unoserver.server --interface 127.0.0.1 --port 2002 --uno-port 2003 & sleep 4 && gunicorn --bind 0.0.0.0:7860 --workers 4 --timeout 120 app:app"]