# === Stage 1: Install dependencies ===
FROM python:3.11-slim-bullseye AS builder

WORKDIR /subgen

# Runtime build tools only — git and ffmpeg not needed here
RUN --mount=type=cache,target=/var/cache/apt,sharing=locked \
    --mount=type=cache,target=/var/lib/apt,sharing=locked \
    apt-get update && apt-get install -y --no-install-recommends \
        tzdata

# Torch — own layer so requirements.txt changes don't bust it
RUN --mount=type=cache,target=/root/.cache/pip \
    pip install --prefix=/install torch torchaudio \
        --extra-index-url https://download.pytorch.org/whl/cpu

# App dependencies — only rebuilds when requirements.txt changes
COPY requirements.txt .
RUN --mount=type=cache,target=/root/.cache/pip \
    pip install --prefix=/install -r requirements.txt \
        --extra-index-url https://download.pytorch.org/whl/cpu

# === Stage 2: Minimal runtime image ===
FROM python:3.11-slim-bullseye AS runtime

WORKDIR /subgen

RUN --mount=type=cache,target=/var/cache/apt,sharing=locked \
    --mount=type=cache,target=/var/lib/apt,sharing=locked \
    apt-get update && apt-get install -y --no-install-recommends \
        ffmpeg curl gosu tzdata \
    && rm -rf /var/lib/apt/lists/*

# Copy installed packages from builder
COPY --from=builder /install /usr/local

# App files last — changes here don't bust the layers above
COPY launcher.py subgen.py language_code.py /subgen/

RUN mkdir -p /cache && chmod 777 /cache

ENV XDG_CACHE_HOME=/cache \
    HF_HOME=/cache/huggingface \
    MPLCONFIGDIR=/cache/matplotlib \
    PYTHONUNBUFFERED=1

COPY entrypoint.sh /entrypoint.sh
RUN chmod +x /entrypoint.sh
ENTRYPOINT ["/entrypoint.sh"]
CMD ["python3", "launcher.py"]