Migrated from import based to config based

modules/system/display-managers/cosmic-greeter.nix

@@ -0,0 +1,11 @@
+{ lib, config, ... }:
+
+with lib;
+
+let
+  cfg = config.settings.display-manager;
+in {
+  config = mkIf (cfg == "cosmic-greeter") {
+    services.displayManager.cosmic-greeter.enable = true;
+  };
+}

modules/system/display-managers/default.nix

@@ -0,0 +1,21 @@
+{ lib, ... }:
+
+with lib;
+
+let
+  cfg = config.settings.display-manager;
+in {
+  options = {
+    settings.display-manager = lib.mkOption {
+      type = lib.types.enum ["sddm" "cosmic-greeter"];  
+      description = ''
+        Specify which display manager to use
+      '';
+    };
+  };
+
+  imports = [
+    ./sddm.nix
+    ./cosmic-greeter.nix
+  ];
+}

modules/system/display-managers/sddm-theme.nix

@@ -0,0 +1,15 @@
+{ pkgs }:
+
+pkgs.stdenv.mkDerivation {
+  name = "sddm-theme";
+  src = pkgs.fetchFromGitHub {
+    owner = "MarianArlt";
+    repo = "sddm-sugar-dark";
+    rev = "ceb2c455663429be03ba62d9f898c571650ef7fe";    
+    sha256 = "0153z1kylbhc9d12nxy9vpn0spxgrhgy36wy37pk6ysq7akaqlvy";
+  };
+  installPhase = ''
+    mkdir -p $out
+    cp -R ./* $out/
+  '';
+}

modules/system/display-managers/sddm.nix

@@ -0,0 +1,20 @@
+{ pkgs, lib, config, ... }:
+
+with lib;
+
+let
+  cfg = config.settings.display-manager;
+in {
+  config = mkIf (cfg == "sddm") {
+    environment.systemPackages = with pkgs; [
+      libsForQt5.qt5.qtquickcontrols2
+      libsForQt5.qt5.qtgraphicaleffects
+    ];
+
+    services.displayManager.sddm = {
+      enable = true;
+      wayland.enable = true;
+      theme = "${import ./sddm-theme.nix { inherit pkgs; }}";
+    };
+  };
+}