{ stdenv
, lib
, chez
, clang
, gmp
, fetchFromGitHub
, makeWrapper
, idris2-version
, srcRev
, gambit
, nodejs
, zsh
}:

# Uses scheme to bootstrap the build of idris2
stdenv.mkDerivation rec {
  pname = "idris2";
  version = idris2-version;

  src = ../.;

  strictDeps = true;
  nativeBuildInputs = [ makeWrapper clang chez ]
    ++ lib.optional stdenv.isDarwin [ zsh ];
  buildInputs = [ chez gmp ];

  prePatch = let match = "$\{GIT_SHA1}"; in
  ''
    patchShebangs --build tests
    sed 's/${match}/${srcRev}/' -i Makefile
  '';

  makeFlags = [ "PREFIX=$(out)" ]
    ++ lib.optional stdenv.isDarwin "OS=";

  # The name of the main executable of pkgs.chez is `scheme`
  buildFlags = [ "bootstrap" "SCHEME=scheme" ];

  checkInputs = [ gambit nodejs ]; # racket ];
  checkFlags = [ "INTERACTIVE=" ];

  # TODO: Move this into its own derivation, such that this can be changed
  #       without having to recompile idris2 every time.
  postInstall = let
    name = "${pname}-${version}";
    globalLibraries = [
      "\\$HOME/.nix-profile/lib/${name}"
      "/run/current-system/sw/lib/${name}"
      "$out/${name}"
    ];
    globalLibrariesPath = builtins.concatStringsSep ":" globalLibraries;
  in ''
    # Remove existing idris2 wrapper that sets incorrect LD_LIBRARY_PATH
    rm $out/bin/idris2

    # The only thing we need from idris2_app is the actual binary
    mv $out/bin/idris2_app/idris2.so $out/bin/idris2
    rm $out/bin/idris2_app/*
    rmdir $out/bin/idris2_app

    # idris2 needs to find scheme at runtime to compile
    # idris2 installs packages with --install into the path given by
    #   IDRIS2_PREFIX. We set that to a default of ~/.idris2, to mirror the
    #   behaviour of the standard Makefile install.
    # TODO: Make support libraries their own derivation such that
    #       overriding LD_LIBRARY_PATH is unnecessary
    wrapProgram "$out/bin/idris2" \
      --set-default CHEZ "${chez}/bin/scheme" \
      --set-default IDRIS2_PREFIX "~/.idris2" \
      --suffix IDRIS2_LIBS ':' "$out/${name}/lib" \
      --suffix IDRIS2_DATA ':' "$out/${name}/support" \
      --suffix IDRIS2_PACKAGE_PATH ':' "${globalLibrariesPath}" \
      --suffix LD_LIBRARY_PATH ':' "$out/${name}/lib"
  '';
}