{ pkgs, ... }:

let
  musnix_channel = (fetchTarball "https://github.com/musnix/musnix/archive/master.tar.gz");
  version = "5.0.10";
  patchlevel = "1";
  linux-surface = pkgs.fetchFromGitHub {
    owner = "jakeday";
    repo = "linux-surface";
    rev = "${version}-${patchlevel}";
    sha256 = "1q8dv7j6gwgszqavb35aswwfn7c7mwkc2xqd2v8gvxnjk7sp4747";
  };

  buildFirmware = (name: subdir: src: pkgs.stdenvNoCC.mkDerivation {
    name = "${name}-firmware";
    src = src;
    nativeBuildInputs = [ pkgs.unzip ];
    sourceRoot = ".";
    installPhase = ''
      mkdir -p $out/lib/firmware/${subdir}
      cp -r * $out/lib/firmware/${subdir}
    '';
  });

  i915-firmware = buildFirmware "i915" "i915" "${linux-surface}/firmware/i915_firmware_skl.zip";
# vaapiIntel = pkgs.vaapiIntel.override { enableHybridCodec = true; };
in {
  imports = [ <nixpkgs/nixos/modules/installer/scan/not-detected.nix>
              musnix_channel ];

  musnix = {
    enable = true;
    alsaSeq.enable = true;
    ffado.enable = true;
    soundcardPciId = "00:14.0";
    kernel.realtime = false;
#    kernel.packages = pkgs.linuxPackages_4_19_rt;
    rtirq.enable = false;
  };

  boot = {
    loader.systemd-boot.enable = true;
    loader.efi.canTouchEfiVariables = true;
    cleanTmpDir = true;
    kernelPackages = pkgs.linuxPackages_surface; # 4_19 worked

    initrd.kernelModules = [ "hid-multitouch" ];
    initrd.availableKernelModules = [ "hid" "surface_acpi" "hid-microsoft" "hid-multitouch" "xhci_pci" "nvme" "usb_storage" "sd_mod" ];
    kernelModules = [ "intel_ipts" "kvm-intel" "hid-microsoft" "hid-multitouch" "uinput" ];
    kernel.sysctl = { 
      "kernel.nmi_watchdog" = 0;
      "fs.inotify.max_user_watches" = 524288; 
      "vm.dirty_writeback_centisecs" = 1500;
    };
    kernelParams = [ "threadirq" ];
    extraModulePackages = [ ];
    extraModprobeConfig = "options snd_hda_intel power_save=1 power_save_controller=Y";
  };

  fileSystems."/" =
    { device = "/dev/disk/by-uuid/8c3a5a07-9ee1-4154-9f3f-6abc379073aa";
      fsType = "ext4";
      options = [ "noatime" ];
    };

  fileSystems."/boot" =
    { device = "/dev/disk/by-uuid/D2A2-C705";
      fsType = "vfat";
    };

  swapDevices = [ ];

  hardware = {
    firmware = with pkgs; [ firmwareLinuxNonfree i915-firmware firmware_surface ];
    cpu.intel.updateMicrocode = true;
    enableAllFirmware = true;
    ksm.enable = true;
    opengl = {
      driSupport = true;
      extraPackages = with pkgs; [ intel-media-driver libvdpau-va-gl vaapiIntel vaapiVdpau intel-media-driver ];
      driSupport32Bit = true;
      extraPackages32 = with pkgs.pkgsi686Linux; [ libvdpau-va-gl vaapiIntel vaapiVdpau ];
    };

    pulseaudio = {
      enable = true;
      support32Bit = true;
      package = pkgs.pulseaudioFull;
      zeroconf.discovery.enable = false;
      extraClientConf = ''
        autospawn = no
      '';
    };

    bluetooth = {
      enable = true;
      powerOnBoot = true;
    };
  };

  powerManagement = {
    enable = true;
    # cpuFreqGovernor = "powersave";
  };
  services.upower.enable = true;

  time.timeZone = "Europe/Berlin";
}