# Reproducible FFmpeg build environment for ffmpeg-kit-next.
#
# ffmpeg-kit-next is Nix-only: the repository ships nix-android.sh and a flake, and
# there is no plain android.sh. Rather than install Nix on a developer machine, the
# whole toolchain lives in this image. It also serves as the reproducibility artifact
# F-Droid expects.
#
# The flake pins Android NDK 27.3.13750724 (r27d) itself and applies
# -Wl,-z,max-page-size=16384 for arm64-v8a and x86_64 in android/jni/Android.mk, so
# the output is 16 KB page-size compliant without needing NDK r28+ on the host.
#
# The base image already provides git, bash, curl and tar. Compilers and build tools
# (make, cmake, autotools, pkg-config) are supplied by the flake's devShell at build
# time, so nothing further is installed here — `nix profile install` would in fact
# collide with the base image's existing profile entries.

FROM docker.io/nixos/nix:2.35.2

# nix-android.sh points NIX_USER_CONF_FILES at the repo's own nix.conf, which enables
# the flakes and nix-command experimental features. Set them here too so that plain
# `nix` invocations behave the same way.
RUN mkdir -p /etc/nix && \
    printf 'experimental-features = nix-command flakes\naccept-flake-config = true\nwarn-dirty = false\nmax-jobs = auto\n' \
        >> /etc/nix/nix.conf

# Upstream's scripts/*.sh use `#!/bin/bash`, but this image provides only /bin/sh.
RUN ln -sf /bin/sh /bin/bash

WORKDIR /work
COPY build-ffmpeg.sh /usr/local/bin/build-ffmpeg.sh
RUN chmod +x /usr/local/bin/build-ffmpeg.sh

ENTRYPOINT ["/usr/local/bin/build-ffmpeg.sh"]