depot/third_party/nixpkgs/pkgs/development/ocaml-modules/logs/default.nix

{
  lib,
  stdenv,
  fetchurl,
  ocaml,
  findlib,
  ocamlbuild,
  topkg,
  result,
  lwt,
  cmdliner,
  fmt,
  fmtSupport ? lib.versionAtLeast ocaml.version "4.08",
  js_of_ocaml,
  jsooSupport ? true,
  lwtSupport ? true,
  cmdlinerSupport ? true,
}:
let
  pname = "logs";
  webpage = "https://erratique.ch/software/${pname}";

  optional_deps = [
    {
      pkg = js_of_ocaml;
      enable_flag = "--with-js_of_ocaml";
      enabled = jsooSupport;
    }
    {
      pkg = fmt;
      enable_flag = "--with-fmt";
      enabled = fmtSupport;
    }
    {
      pkg = lwt;
      enable_flag = "--with-lwt";
      enabled = lwtSupport;
    }
    {
      pkg = cmdliner;
      enable_flag = "--with-cmdliner";
      enabled = cmdlinerSupport;
    }
  ];
  enable_flags = lib.concatMap (d: [
    d.enable_flag
    (lib.boolToString d.enabled)
  ]) optional_deps;
  optional_buildInputs = map (d: d.pkg) (lib.filter (d: d.enabled) optional_deps);
in

if lib.versionOlder ocaml.version "4.03" then
  throw "logs is not available for OCaml ${ocaml.version}"
else

  stdenv.mkDerivation rec {
    name = "ocaml${ocaml.version}-${pname}-${version}";
    version = "0.7.0";

    src = fetchurl {
      url = "${webpage}/releases/${pname}-${version}.tbz";
      sha256 = "1jnmd675wmsmdwyb5mx5b0ac66g4c6gpv5s4mrx2j6pb0wla1x46";
    };

    nativeBuildInputs = [
      ocaml
      findlib
      ocamlbuild
      topkg
    ];
    buildInputs = [ topkg ] ++ optional_buildInputs;
    propagatedBuildInputs = [ result ];

    strictDeps = true;

    buildPhase = "${topkg.run} build ${lib.escapeShellArgs enable_flags}";

    inherit (topkg) installPhase;

    meta = with lib; {
      description = "Logging infrastructure for OCaml";
      homepage = webpage;
      inherit (ocaml.meta) platforms;
      maintainers = [ maintainers.sternenseemann ];
      license = licenses.isc;
    };
  }