ARG DEBIAN_VERSION=stable-slim

# ==========================================
# Stage 1: Runtime (Fully Cached)
# ==========================================
FROM debian:${DEBIAN_VERSION} AS base
RUN apt-get update && apt-get install -y --no-install-recommends \
    ffmpeg python3 python3-pip python3-venv curl ca-certificates unzip \
    && rm -rf /var/lib/apt/lists/*

# Virtualenv so pip doesn't clash with Debian's system Python.
# yt-dlp and the bgutil plugin MUST live in the same environment
# for entry-point plugin discovery to work.
RUN python3 -m venv /opt/venv
ENV PATH="/opt/venv/bin:${PATH}"

# Version pins matter here:
#   - curl-cffi < 0.16  : yt-dlp's impersonation bridge rejects newer
#                         releases as "unsupported" and silently disables
#                         browser fingerprinting.
#   - yt-dlp-get-pot is intentionally OMITTED. That package is archived
#     and its last release (0.3.0) predates the built-in PO Token
#     provider framework in yt-dlp >= 2025.05.22. The bgutil plugin
#     now registers directly with yt-dlp; installing the old framework
#     would conflict with the built-in one.
#   - bgutil-ytdlp-pot-provider >= 1.3 : HTTP mode support, compatible
#     with yt-dlp's built-in PO Token provider framework.
RUN pip install --no-cache-dir --upgrade pip && \
    pip install --no-cache-dir \
        "curl-cffi>=0.10,<0.16" \
        requests \
        yt-dlp \
        "bgutil-ytdlp-pot-provider>=1.3"

# ==========================================
# Stage 2: Fetcher (Cache busted for deno only)
# ==========================================
FROM alpine:latest AS fetcher
ARG TARGETARCH

RUN apk add --no-cache curl unzip

# Declaring CACHE_BUST and referencing it inside the RUN forces
# Docker to rebuild the download layer on every build.
ARG CACHE_BUST

RUN echo "Cache bust: ${CACHE_BUST}" && \
    DETECTED_ARCH="${TARGETARCH:-$(uname -m)}" && \
    if [ "$DETECTED_ARCH" = "amd64" ] || [ "$DETECTED_ARCH" = "x86_64" ]; then \
        D_ARCH="x86_64"; \
    else \
        D_ARCH="aarch64"; \
    fi && \
    curl -fsSL "https://github.com/denoland/deno/releases/latest/download/deno-${D_ARCH}-unknown-linux-gnu.zip" -o /deno.zip && \
    unzip /deno.zip -d / && chmod a+rx /deno

# ==========================================
# Stage 3: Final
# ==========================================
FROM base AS final

COPY --from=fetcher /deno /usr/local/bin/deno

# Fallback for the bgutil HTTP plugin when no extractor-arg is forwarded.
# Both this and the --extractor-args in tuber.py point at the same server.
ENV BGW_HTTP_BASE_URL="http://pot:4416"

ENV XDG_CONFIG_HOME=/dev/shm/yt-dlp/config
ENV XDG_CACHE_HOME=/dev/shm/yt-dlp/cache