FROM python:3.11-slim

# Set environment variables
ENV PYTHONUNBUFFERED=1 \
    PORT=7860 \
    HOME=/home/user \
    HF_HOME=/tmp/huggingface \
    TRANSFORMERS_CACHE=/tmp/huggingface

# Install system dependencies
RUN apt-get update && apt-get install -y --no-install-recommends \
    build-essential \
    curl \
    git \
    && rm -rf /var/lib/apt/lists/*

# Create non-root user for Hugging Face Spaces (UID 1000)
RUN useradd -m -u 1000 user
WORKDIR /home/user/app

# Install PyTorch CPU first to keep image lightweight and fast
RUN pip install --no-cache-dir torch --index-url https://download.pytorch.org/whl/cpu

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

# Create HF cache directory with correct permissions
RUN mkdir -p /tmp/huggingface && chown -R user:user /tmp/huggingface

# Copy application files
COPY --chown=user:user . .

USER user

# Hugging Face Space default port
EXPOSE 7860

# Start FastAPI application
CMD ["python", "api_server.py"]