{ lib
, stdenv
, fetchFromGitHub
, docutils
, meson
, ninja
, pkg-config
, dbus
, linuxHeaders
, systemd
}:

let
  dep = { pname, version, hash, buildInputs ? [ ] }:
    stdenv.mkDerivation {
      inherit pname version;
      src = fetchFromGitHub {
        owner = "c-util";
        repo = pname;
        rev = version;
        inherit hash;
      };
      nativeBuildInputs = [ meson ninja pkg-config ];
      inherit buildInputs;
    };

  # These libraries are not used outside of dbus-broker.
  #
  # If that changes, we can always break them out, but they are essentially
  # part of the dbus-broker project, just in separate repositories.
  c-dvar = dep { pname = "c-dvar"; version = "v1"; hash = "sha256-P7y7gUHXQn2eyS6IcV7m7yGy4VGtQ2orgBkS7Y729ZY="; buildInputs = [ c-stdaux c-utf8 ]; };
  c-ini = dep { pname = "c-ini"; version = "v1"; hash = "sha256-VKxoGexMcquakMmiH5IJt0382TjkV1FLncTSyEqf4X0="; buildInputs = [ c-list c-rbtree c-stdaux c-utf8 ]; };
  c-list = dep { pname = "c-list"; version = "v3"; hash = "sha256-fp3EAqcbFCLaT2EstLSzwP2X13pi2EFpFAullhoCtpw="; };
  c-rbtree = dep { pname = "c-rbtree"; version = "v3"; hash = "sha256-ExSPgNqhTjSwRgYfZOAyoaehOpFNHKFqPYkcCfptkrs="; buildInputs = [ c-stdaux ]; };
  c-shquote = dep { pname = "c-shquote"; version = "v1"; hash = "sha256-Ze1enX0VJ6Xi5e4EhWzaiHc7PnuaifrUP+JuJnauv5c="; buildInputs = [ c-stdaux ]; };
  c-stdaux = dep { pname = "c-stdaux"; version = "v1"; hash = "sha256-/D+IFdqn1XHDfdOsDnLMO5IHQ5B4P4ELyMpRcPBg/4s="; };
  c-utf8 = dep { pname = "c-utf8"; version = "v1"; hash = "sha256-QEnjmfQ6kxJdsHfyRgXAlP+oGrKLYQ0m9r+D2L+pizI="; buildInputs = [ c-stdaux ]; };

in
stdenv.mkDerivation rec {
  pname = "dbus-broker";
  version = "32";

  src = fetchFromGitHub {
    owner = "bus1";
    repo = "dbus-broker";
    rev = "v${version}";
    hash = "sha256-PVdRyg/t6D3HjSHeap5L8AiEm39iSO5qXohLw2UAUYY=";
  };

  patches = [ ./paths.patch ];

  nativeBuildInputs = [ docutils meson ninja pkg-config ];

  buildInputs = [
    c-dvar
    c-ini
    c-list
    c-rbtree
    c-shquote
    c-stdaux
    c-utf8
    dbus
    linuxHeaders
    systemd
  ];

  mesonFlags = [
    # while we technically support 4.9 and 4.14, the NixOS module will throw an
    # error when using a kernel that's too old
    "-D=linux-4-17=true"
    "-D=system-console-users=gdm,sddm,lightdm"
  ];

  PKG_CONFIG_SYSTEMD_SYSTEMDSYSTEMUNITDIR = "${placeholder "out"}/lib/systemd/system";
  PKG_CONFIG_SYSTEMD_SYSTEMDUSERUNITDIR = "${placeholder "out"}/lib/systemd/user";
  PKG_CONFIG_SYSTEMD_CATALOGDIR = "${placeholder "out"}/lib/systemd/catalog";

  postInstall = ''
    install -Dm444 $src/README.md $out/share/doc/dbus-broker/README

    sed -i $out/lib/systemd/{system,user}/dbus-broker.service \
      -e 's,^ExecReload.*busctl,ExecReload=${systemd}/bin/busctl,'
  '';

  doCheck = true;

  meta = with lib; {
    description = "Linux D-Bus Message Broker";
    homepage = "https://github.com/bus1/dbus-broker/wiki";
    license = licenses.asl20;
    maintainers = with maintainers; [ peterhoeg ];
    platforms = platforms.linux;
  };
}