FROM python:3.12-slim AS builder

ENV PYTHONDONTWRITEBYTECODE=1 \
    PYTHONUNBUFFERED=1 \
    UV_LINK_MODE=copy \
    UV_VERSION=0.4.17 \
    UV_PROJECT_ENVIRONMENT=/opt/venv

WORKDIR /app

# Install build prerequisites, fetch uv, then remove leftover apt metadata.
RUN apt-get update && apt-get install -y --no-install-recommends curl ca-certificates build-essential && \
    rm -rf /var/lib/apt/lists/*

RUN curl -LsSf https://astral.sh/uv/install.sh | sh -s -- --version "${UV_VERSION}"

# Pre-copy manifests for better layer caching.
COPY pyproject.toml uv.lock requirements.txt ./

RUN /root/.local/bin/uv sync --frozen --no-dev --python /usr/local/bin/python && \
    /root/.local/bin/uv cache prune --ci

FROM python:3.12-slim AS runtime

ARG APP_PORT=8000

ENV APP_ENV=local \
    APP_PORT=${APP_PORT}

WORKDIR /app

# Runtime dependencies required by packages like faiss-cpu.
RUN apt-get update && apt-get install -y --no-install-recommends libgomp1 && \
    rm -rf /var/lib/apt/lists/*

# Bring in the pre-built virtual environment from the builder stage.
COPY --from=builder /opt/venv /opt/venv

# Ship only the application sources in the runtime image.
COPY . .

ENV PATH="/opt/venv/bin:${PATH}" \
    VIRTUAL_ENV="/opt/venv"

EXPOSE ${APP_PORT}

CMD ["sh", "-c", "python server.py --host ${HOST:-0.0.0.0} --port ${APP_PORT:-8000}"]