#!/usr/bin/env sh
set -eu

ocaml_version="5.4.1"
dune_pin="git+https://github.com/futurGH/dune#50fd4c83186300033d30139c82f0e3d288278de2"
dune_version_marker="50fd4c8"

if ! command -v opam >/dev/null 2>&1; then
  echo "opam is required. Install it from https://opam.ocaml.org/doc/Install.html" >&2
  exit 1
fi

if [ -d _opam ]; then
  eval "$(opam env --switch=. --set-switch)"
  current_ocaml="$(ocamlc -version 2>/dev/null || true)"
else
  current_ocaml=""
fi

if [ "$current_ocaml" != "$ocaml_version" ]; then
  if [ -d _opam ]; then
    opam switch remove . -y
  fi

  opam switch create . "$ocaml_version" --no-install
  eval "$(opam env --switch=. --set-switch)"
fi

if ! command -v dune >/dev/null 2>&1 || ! dune --version | grep -q "$dune_version_marker"; then
  opam pin add dune "$dune_pin" -y

  if ! dune --version | grep -q "$dune_version_marker"; then
    opam reinstall dune -y
  fi
fi

dune pkg lock
dune build