ARG ELIXIR_VERSION=1.18.4
ARG OTP_VERSION=27.2.4
ARG DEBIAN_VERSION=bullseye-20250520-slim

ARG BUILDER_IMAGE="hexpm/elixir:${ELIXIR_VERSION}-erlang-${OTP_VERSION}-debian-${DEBIAN_VERSION}"
# Use static distroless image with only statically linked binaries
ARG RUNNER_IMAGE="gcr.io/distroless/static-debian11:nonroot"

FROM ${BUILDER_IMAGE} AS builder

# install build dependencies
RUN apt-get update -y && \
    apt-get upgrade -y && \
    apt-get install -y build-essential git && \
    apt-get clean && \
    rm -rf /var/lib/apt/lists/*

# prepare build dir
WORKDIR /app

# install hex + rebar
RUN mix local.hex --force && \
    mix local.rebar --force

# set build ENV
ENV MIX_ENV="prod"

# install mix dependencies
COPY mix.exs mix.lock ./
RUN mix deps.get --only $MIX_ENV
RUN mkdir config

# copy compile-time config files before we compile dependencies
COPY config/config.exs config/${MIX_ENV}.exs config/
RUN mix deps.compile

COPY priv priv
COPY lib lib
COPY assets assets

# compile assets
RUN mix assets.deploy

# Compile the release
RUN mix compile

# Changes to config/runtime.exs don't require recompiling the code
COPY config/runtime.exs config/

COPY rel rel
RUN mix release

# Create intermediate stage to prepare statically linked binaries
FROM debian:bullseye-slim AS static-builder

# Install tools to create static binaries
RUN apt-get update -y && \
    apt-get install -y --no-install-recommends \
    musl-tools \
    musl-dev \
    upx-ucl \
    file \
    && apt-get clean && \
    rm -rf /var/lib/apt/lists/*

# Copy the release from builder
COPY --from=builder /app/_build/prod/rel/aprs /app

# Create a wrapper script that can be statically linked
RUN cat > /wrapper.c << 'EOF'
#include <unistd.h>
#include <sys/wait.h>
#include <stdio.h>
#include <stdlib.h>

int main(int argc, char *argv[]) {
    char *args[] = {"/app/bin/server", "start", NULL};
    execv("/app/bin/server", args);
    perror("execv failed");
    return 1;
}
EOF

# This approach won't work well with Erlang/Elixir as they require dynamic linking
# Let's use a different approach with a minimal runtime environment

# Runtime preparation stage
FROM debian:bullseye-slim AS runtime-prep

# Install only the absolute minimum runtime dependencies
RUN apt-get update -y && \
    apt-get install -y --no-install-recommends \
    libc6 \
    libssl1.1 \
    libcrypto++6 \
    libncurses5 \
    libtinfo5 \
    ca-certificates \
    && apt-get clean && \
    rm -rf /var/lib/apt/lists/*

# Copy necessary libraries to a clean location
RUN mkdir -p /runtime/lib/x86_64-linux-gnu /runtime/usr/lib/x86_64-linux-gnu /runtime/etc/ssl

# Copy essential libraries
RUN cp -L /lib/x86_64-linux-gnu/libc.so.6 /runtime/lib/x86_64-linux-gnu/ && \
    cp -L /lib/x86_64-linux-gnu/libdl.so.2 /runtime/lib/x86_64-linux-gnu/ && \
    cp -L /lib/x86_64-linux-gnu/libpthread.so.0 /runtime/lib/x86_64-linux-gnu/ && \
    cp -L /lib/x86_64-linux-gnu/libm.so.6 /runtime/lib/x86_64-linux-gnu/ && \
    cp -L /lib/x86_64-linux-gnu/librt.so.1 /runtime/lib/x86_64-linux-gnu/ && \
    cp -L /lib/x86_64-linux-gnu/libtinfo.so.5 /runtime/lib/x86_64-linux-gnu/ && \
    cp -L /usr/lib/x86_64-linux-gnu/libssl.so.1.1 /runtime/usr/lib/x86_64-linux-gnu/ && \
    cp -L /usr/lib/x86_64-linux-gnu/libcrypto.so.1.1 /runtime/usr/lib/x86_64-linux-gnu/ && \
    cp -L /usr/lib/x86_64-linux-gnu/libncurses.so.5 /runtime/usr/lib/x86_64-linux-gnu/ && \
    cp -L /lib64/ld-linux-x86-64.so.2 /runtime/lib64/ || mkdir -p /runtime/lib64 && cp -L /lib64/ld-linux-x86-64.so.2 /runtime/lib64/

# Copy CA certificates
RUN cp -r /etc/ssl/certs /runtime/etc/ssl/

# Final static distroless stage
FROM ${RUNNER_IMAGE}

# Copy minimal runtime environment
COPY --from=runtime-prep /runtime /

# Set environment variables
ENV MIX_ENV="prod" \
    LANG=C.UTF-8 \
    PATH="/app/bin:$PATH" \
    HISTFILE=/dev/null \
    HOME=/tmp \
    ERL_AFLAGS="+S 1:1 +A 1 +K true" \
    PHX_SERVER=true

WORKDIR /app

# Copy the Elixir release
COPY --from=builder --chown=65532:65532 /app/_build/prod/rel/aprs ./

# Security labels
LABEL org.opencontainers.image.vendor="APRS.me" \
    org.opencontainers.image.title="APRS.me Server (Static Distroless)" \
    org.opencontainers.image.description="APRS.me server with static distroless base - maximum security" \
    security.distroless="true" \
    security.static="true" \
    security.nonroot="true" \
    security.no-shell="true"

# Note: Static distroless is very restrictive and may not work with all Erlang features
# Consider using cc-debian11:nonroot for better compatibility

ENTRYPOINT ["/app/bin/server"]
EXPOSE $PORT