# Dockerfile for deploying Dialectica on Hugging Face Spaces (Docker SDK).
#
# Notes specific to Spaces:
#   * The app must listen on port 7860.
#   * Only /tmp is writable, so all model caches are redirected there.
#   * The fine-tuned DistilBERT is pulled from the Hugging Face Hub at startup
#     (set MODEL_REPO below), so it does not need to be baked into the image.

FROM python:3.11-slim

# System deps for PyMuPDF and general builds.
RUN apt-get update && apt-get install -y --no-install-recommends \
    build-essential \
    && rm -rf /var/lib/apt/lists/*

# Redirect all model/library caches to /tmp (the only writable dir on Spaces).
ENV HF_HOME=/tmp/hf_home \
    TRANSFORMERS_CACHE=/tmp/hf_home \
    SENTENCE_TRANSFORMERS_HOME=/tmp/st_home \
    XDG_CACHE_HOME=/tmp/cache \
    MPLCONFIGDIR=/tmp/mpl

ENV PYTHONUNBUFFERED=1

WORKDIR /app

# Install Python dependencies first for better layer caching.
# Install the CPU build of torch explicitly to avoid pulling large CUDA wheels.
COPY requirements-app.txt .
RUN pip install --no-cache-dir "torch>=2.2.0" --index-url https://download.pytorch.org/whl/cpu
RUN pip install --no-cache-dir --upgrade -r requirements-app.txt

# Copy the application code.
COPY . .

# Spaces expects the app on port 7860.
EXPOSE 7860

CMD ["uvicorn", "main:app", "--host", "0.0.0.0", "--port", "7860"]