{ cairo, cmake, fetchgit, libXdmcp, libpthreadstubs, libxcb, pcre, pkgconfig
, python2, stdenv, xcbproto, xcbutil, xcbutilcursor, xcbutilimage
, xcbutilrenderutil, xcbutilwm, xcbutilxrm, makeWrapper

# optional packages-- override the variables ending in 'Support' to enable or
# disable modules
, alsaSupport   ? true,  alsaLib       ? null
, githubSupport ? false, curl          ? null
, mpdSupport    ? false, mpd_clientlib ? null
, pulseSupport  ? false, libpulseaudio ? null
, iwSupport     ? false, wirelesstools ? null
, nlSupport     ? true,  libnl         ? null
, i3Support ? false, i3GapsSupport ? false, i3 ? null, i3-gaps ? null, jsoncpp ? null
}:

assert alsaSupport   -> alsaLib       != null;
assert githubSupport -> curl          != null;
assert mpdSupport    -> mpd_clientlib != null;
assert pulseSupport  -> libpulseaudio != null;

assert iwSupport     -> ! nlSupport && wirelesstools != null;
assert nlSupport     -> ! iwSupport && libnl         != null;

assert i3Support     -> ! i3GapsSupport && jsoncpp != null && i3      != null;
assert i3GapsSupport -> ! i3Support     && jsoncpp != null && i3-gaps != null;

stdenv.mkDerivation rec {
    name = "polybar-${version}";
    version = "3.2.1";
    src = fetchgit {
      url = "https://github.com/jaagr/polybar";
      rev = version;
      sha256 = "1z45swj2l0h8x8li7prl963cgl6zm3birsswpij8qwcmjaj5l8vz";
    };

    meta = with stdenv.lib; {
      description = "A fast and easy-to-use tool for creating status bars";
      longDescription = ''
        Polybar aims to help users build beautiful and highly customizable
        status bars for their desktop environment, without the need of
        having a black belt in shell scripting.
      '';
      license = licenses.mit;
      maintainers = [ maintainers.afldcr ];
      platforms = platforms.unix;
    };

    buildInputs = [
      cairo libXdmcp libpthreadstubs libxcb pcre python2 xcbproto xcbutil
      xcbutilcursor xcbutilimage xcbutilrenderutil xcbutilwm xcbutilxrm

      (if alsaSupport   then alsaLib       else null)
      (if githubSupport then curl          else null)
      (if mpdSupport    then mpd_clientlib else null)
      (if pulseSupport  then libpulseaudio else null)

      (if iwSupport     then wirelesstools else null)
      (if nlSupport     then libnl         else null)

      (if i3Support || i3GapsSupport then jsoncpp else null)
      (if i3Support then i3 else null)
      (if i3GapsSupport then i3-gaps else null)

      (if i3Support || i3GapsSupport then makeWrapper else null)
    ];

    postConfigure = ''
      substituteInPlace ../include/settings.hpp --replace \
        "${stdenv.cc}" "${stdenv.cc.name}"
    '';

    postInstall = if (i3Support || i3GapsSupport) then ''
      wrapProgram $out/bin/polybar \
        --prefix PATH : "${if i3Support then i3 else i3-gaps}/bin"
    '' else "";

    nativeBuildInputs = [
      cmake pkgconfig
    ];
}