# syntax=docker/dockerfile:1

# Linux on ARM64 cross-build environment (aarch64-linux-gnu), isolated from the
# x86_64 Linux image and the Windows images.
#
# Toolchain: clang-21 + libc++ with the arm64 libc++ (for `import std;`), the
# arm64 glibc from `gcc-aarch64-linux-gnu`, arm64 SDL3 from `libsdl3-dev:arm64`,
# and lld as the linker. The arm64 packages are installed with dpkg multiarch
# (`arm64` added to the sources); the native clang/cmake build tools stay amd64.

FROM ubuntu:26.04 AS dev

ENV DEBIAN_FRONTEND=noninteractive

ARG APT_MIRROR=""
RUN if [ -n "$APT_MIRROR" ]; then \
        sed -i -e "s|http://archive.ubuntu.com/ubuntu|${APT_MIRROR}|g" \
               -e "s|http://security.ubuntu.com/ubuntu|${APT_MIRROR}|g" \
               -e "s|http://ports.ubuntu.com/ubuntu-ports|${APT_MIRROR}|g" \
               /etc/apt/sources.list /etc/apt/sources.list.d/*.sources 2>/dev/null || true; \
    fi

# Enable the arm64 architecture on top of the emulated amd64 userland.
RUN dpkg --add-architecture arm64

RUN --mount=type=cache,target=/var/lib/apt,sharing=locked \
    --mount=type=cache,target=/var/cache/apt,sharing=locked \
    for attempt in 1 2 3 4 5; do \
        apt-get -o Acquire::Retries=5 update && break; \
        echo "apt-get update failed (attempt $attempt), retrying"; \
        sleep 5; \
    done \
    && apt-get -o Acquire::Retries=5 install -y --no-install-recommends \
        ca-certificates \
        clang-21 \
        cmake \
        dpkg-dev \
        file \
        gcc-aarch64-linux-gnu \
        libc++-21-dev:arm64 \
        libc++abi-21-dev:arm64 \
        libsdl3-dev:arm64 \
        libunwind-21-dev:arm64 \
        lld-21 \
        ninja-build \
        pkg-config \
        python3 \
    && rm -rf /var/lib/apt/lists/*

ENV CC=clang-21
ENV CXX=clang++-21
# Point pkg-config at the arm64 packages so SDL3 resolves to the aarch64 build.
ENV PKG_CONFIG_LIBDIR=/usr/lib/aarch64-linux-gnu/pkgconfig

WORKDIR /work
COPY . .

RUN cmake -S . -B build/linux-arm64 -G Ninja \
        -DCMAKE_TOOLCHAIN_FILE=cmake/toolchains/clang-aarch64-linux-gnu.cmake \
        -DCMAKE_BUILD_TYPE=Release \
        -DOPENRA3_DISTRO_TAG=ubuntu26.04 \
    && cmake --build build/linux-arm64 -j \
    && (cd build/linux-arm64 && cpack -G DEB)

# deploy target: runtime dependencies + final binary, minimal and fast. This is
# an arm64 image; build it on (or with emulation for) an arm64 host.
FROM --platform=linux/arm64 ubuntu:26.04 AS deploy

ENV DEBIAN_FRONTEND=noninteractive

RUN --mount=type=cache,target=/var/lib/apt,sharing=locked \
    --mount=type=cache,target=/var/cache/apt,sharing=locked \
    apt-get -o Acquire::Retries=5 update \
    &&     apt-get -o Acquire::Retries=5 install -y --no-install-recommends \
        libc++1 \
        libc++abi1 \
        libsdl3-0 \
        libvulkan1 \
    && rm -rf /var/lib/apt/lists/*

WORKDIR /app
COPY --from=dev /work/build/linux-arm64/bin/openra3 /app/openra3

ENTRYPOINT ["/app/openra3"]