# syntax=docker/dockerfile:1.6
#
# Pre-built CI test image. Extends the hexpm/elixir image with:
#   * build-essential + git + curl + ca-certificates + cdo
#   * hex + rebar
#   * Precompiled EXLA NIF + object files at /opt/exla-cache/
#
# EXLA's cached_make copies libexla.so to deps/exla/cache/, but Make
# still tries to compile .o files when they're missing (they don't
# survive mix deps.get). We save the full cache/ directory and restore
# it in the test step before mix test runs.
#
# Rebuild whenever mix.exs changes elixir/exla/xla versions or c_src/
# files change (the cache key auto-invalidates).
#
# Built by .forgejo/workflows/build.yaml (build-ci-image job).

ARG ELIXIR_IMAGE="docker.io/hexpm/elixir:1.20.1-erlang-29.0.2-debian-trixie-20260518-slim"

FROM ${ELIXIR_IMAGE} AS builder

RUN export DEBIAN_FRONTEND=noninteractive && \
    apt-get update -qq && \
    apt-get install -y -qq git curl ca-certificates build-essential cdo && \
    rm -rf /var/lib/apt/lists/*

RUN mix local.hex --force && mix local.rebar --force

WORKDIR /tmp/exla_warm

COPY mix.exs mix.lock /tmp/exla_warm/
COPY vendor /tmp/exla_warm/vendor

RUN mkdir -p /tmp/exla_warm/config && \
    printf 'import Config\nconfig :nx, :default_backend, EXLA.Backend\n' > /tmp/exla_warm/config/config.exs

# Compile all deps. EXLA's cached_make downloads the XLA archive, compiles
# the C++ NIF, and caches libexla.so at ~/.cache/xla/exla/{key}/.
RUN mix deps.get && mix deps.compile

# Save the full build cache (libexla.so + .o files + xla_extension lib)
# so Make finds all targets already built when restored in the test step.
RUN mkdir -p /opt/exla-cache && \
    cp -a deps/exla/cache /opt/exla-cache/cache

FROM ${ELIXIR_IMAGE} AS final

RUN export DEBIAN_FRONTEND=noninteractive && \
    apt-get update -qq && \
    apt-get install -y -qq git curl ca-certificates build-essential cdo && \
    rm -rf /var/lib/apt/lists/*

RUN mix local.hex --force && mix local.rebar --force

# XLA archive download + cached libexla.so (cached_make fast path).
COPY --from=builder /root/.cache/xla /root/.cache/xla

# Pre-built EXLA object files + libexla.so + xla_extension/ lib.
# Restored in the test step: cp -a /opt/exla-cache/cache /app/deps/exla/cache
COPY --from=builder /opt/exla-cache /opt/exla-cache

WORKDIR /app