FROM python:3.10-slim

# 1) Install system deps (Graphviz provides `dot`)
USER root
RUN apt-get update && apt-get install -y --no-install-recommends \
    graphviz \
    && rm -rf /var/lib/apt/lists/*

# 2) Create non-root user
RUN useradd -m -u 1000 user

ENV HOME=/home/user \
    PATH=/home/user/.local/bin:$PATH

WORKDIR $HOME/app

# 3) Copy only requirements first for better caching
COPY requirements.txt $HOME/app/requirements.txt
RUN pip3 install --no-cache-dir -r requirements.txt

# 4) Copy the rest of the app
COPY . $HOME/app

# 5) Fix ownership (no 777 needed)
RUN chown -R user:user $HOME/app

USER user

# Optional: sanity check during build (remove later if you want)
# RUN which dot && dot -V

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