FROM python:3.11-slim

# Set environment variables
ENV PYTHONDONTWRITEBYTECODE 1
ENV PYTHONUNBUFFERED 1
ENV PORT 8080

WORKDIR /app

# Install system dependencies for some python packages if needed
RUN apt-get update && apt-get install -y --no-install-recommends \
    build-essential \
    && rm -rf /var/lib/apt/lists/*

# Install python dependencies
COPY requirements.txt .
RUN pip install --no-cache-dir -r requirements.txt

# Copy project files
COPY . .

# Download NLTK resources during build to optimize startup
RUN python -c "import nltk; nltk.download('punkt'); nltk.download('stopwords'); nltk.download('punkt_tab'); nltk.download('words'); nltk.download('wordnet')"

# Expose port
EXPOSE 8080

# Start the application using shell form to allow environment variable expansion
CMD uvicorn main:app --host 0.0.0.0 --port ${PORT:-8080}