# Multi-stage build for the Shadix docs site (the dev harness compiled for
# production as the `shadix_docs` release, MIX_ENV=docs).
#
# Stage 1 builds assets + the OTP release; stage 2 is a slim runtime that only
# carries the assembled release. Both stages are Alpine (musl): the release is
# dynamically linked against the builder's libc, so the runner libc must match.
# Base image versions track mise.toml (Erlang 29.0.2 / Elixir 1.20.1).

ARG ELIXIR_IMAGE="hexpm/elixir:1.20.1-erlang-29.0.2-alpine-3.21.7"
ARG RUNNER_IMAGE="alpine:3.21"
ARG NODE_IMAGE="node:24-alpine"

# ---- Stage 1: build ----------------------------------------------------------
FROM ${ELIXIR_IMAGE} AS builder

# Node + npm are needed only to install the assets/ JS deps (@floating-ui/dom)
# that esbuild bundles. Copy the musl build from node:alpine so it runs here.
COPY --from=node:24-alpine /usr/local/bin/node /usr/local/bin/node
COPY --from=node:24-alpine /usr/local/lib/node_modules /usr/local/lib/node_modules
RUN ln -sf /usr/local/lib/node_modules/npm/bin/npm-cli.js /usr/local/bin/npm

# build-base/git for any native build steps; libstdc++ + libgcc let the copied
# node binary and the esbuild/tailwind standalone CLIs run on musl.
RUN apk add --no-cache build-base git ca-certificates libstdc++ libgcc

WORKDIR /app

# Build in the dedicated docs environment.
ENV MIX_ENV="docs"
# Give hex more headroom on slow/flaky networks (default is 15s per request).
ENV HEX_HTTP_TIMEOUT=120

RUN for i in 1 2 3 4 5; do mix local.hex --force && mix local.rebar --force && break; \
      echo "local.hex/rebar attempt $i failed; retrying..."; sleep 5; done

# Fetch deps first (cached unless mix.exs/mix.lock/config change). Retry to ride
# out transient hex registry timeouts.
COPY mix.exs mix.lock ./
COPY config config
RUN for i in 1 2 3 4 5; do mix deps.get --only $MIX_ENV && break; \
      echo "deps.get attempt $i failed; retrying..."; sleep 5; done
RUN mix deps.compile

# Install the esbuild/tailwind standalone binaries used by `mix assets.build`.
# On musl these resolve to the -musl builds automatically.
RUN mix esbuild.install --if-missing && mix tailwind.install --if-missing

# Install assets JS deps (esbuild resolves @floating-ui/dom from here).
COPY assets assets
RUN cd assets && npm install

# Copy source and build assets + the release.
COPY lib lib
COPY website website
COPY priv priv
RUN mix assets.build
RUN mix compile
RUN mix release shadix_docs

# ---- Stage 2: runtime --------------------------------------------------------
FROM ${RUNNER_IMAGE} AS runner

# Runtime libs the BEAM links against on Alpine.
RUN apk add --no-cache libstdc++ openssl ncurses-libs libgcc ca-certificates

# musl ships a built-in UTF-8 locale; just point the BEAM at it.
ENV LANG=C.UTF-8

WORKDIR /app
RUN chown nobody /app

ENV MIX_ENV="docs"
# Fly maps its proxy to this port; runtime.exs also defaults to 8080.
ENV PORT=8080

COPY --from=builder --chown=nobody:root /app/_build/docs/rel/shadix_docs ./

USER nobody

EXPOSE 8080

CMD ["/app/bin/shadix_docs", "start"]