nixos-config/modules/greetd/default.nix

{
  pkgs,
  config,
  lib,
  ...
}:
with lib;
let
  cfg = config.eboskma.greetd;
  steamCfg = config.programs.steam;

  style = builtins.readFile ./greetd.css;

  swaySession = pkgs.writeShellScript "sway-session" ''
    ${config.programs.sway.package}/bin/sway --unsupported-gpu
  '';

  steam-gamescope =
    let
      exports = builtins.attrValues (
        builtins.mapAttrs (n: v: "export ${n}=${v}") steamCfg.gamescopeSession.env
      );
    in
    pkgs.writeShellScriptBin "steam-gamescope" ''
      ${builtins.concatStringsSep "\n" exports}
      gamescope --steam ${toString steamCfg.gamescopeSession.args} -- steam -tenfoot -pipewire-dmabuf
    '';

  envVars = concatStringsSep " " (builtins.attrNames config.environment.sessionVariables);

  moduleStr = moduleType: name: attrs: ''
    ${moduleType} "${name}" {
    ${builtins.concatStringsSep "\n" (lib.mapAttrsToList (name: value: "${name} ${value}") attrs)}
    }
  '';

  inputStr = moduleStr "input";
  outputStr = moduleStr "output";
in
{
  options.eboskma.greetd = {
    enable = mkEnableOption "enable greetd";
    sway = mkEnableOption "sway";
    steam = mkEnableOption "steam";
    wayvnc = mkEnableOption "wayvnc";
    output = mkOption {
      description = "An attribute set that defines output modules. See the sway-output(5) manpage for options";
      type = types.attrsOf (types.attrsOf types.str);
      default = { };
    };
    input = mkOption {
      description = "An attribute set that defines input modules. See the sway-input(5) manpage for options";
      type = types.attrsOf (types.attrsOf types.str);
      default = { };
    };
    wallpaper = mkOption {
      description = "Path to an image to use as wallpaper";
      type = types.path;
    };
  };

  config = mkIf cfg.enable {
    services.greetd = {
      enable = true;
      restart = true;
      settings = {
        default_session = {
          command = "${config.programs.sway.package}/bin/sway --unsupported-gpu --config /etc/greetd/sway-config";
        };
      };
    };

    programs.regreet = {
      enable = false;
      settings = {
        background = {
          path = cfg.wallpaper;
          fit = "Cover";
        };

        GTK = {
          application_prefer_dark_theme = true;
          theme_name = "elementary";
          cursor_theme = "elementary";
          icon_theme_name = "elementary";
          font_name = "Iosevka Aile 16";
        };

        commands = {
          reboot = [
            "systemctl"
            "reboot"
          ];
          poweroff = [
            "systemctl"
            "poweroff"
          ];
        };
      };
    };

    security.pam.services.greetd.u2fAuth = false;

    # exec "${pkgs.greetd.regreet}/bin/regreet; swaymsg exit"

    networking.firewall.allowedTCPPorts = lib.mkIf (cfg.wayvnc && !config.services.tailscale.enable) [
      5900
    ];

    environment = {
      systemPackages = with pkgs; [
        pantheon.elementary-gtk-theme
        pantheon.elementary-icon-theme
      ];
      etc = {
        "greetd/sway-config" = {
          text = lib.concatStringsSep "\n" (
            (lib.optional cfg.wayvnc "exec ${pkgs.wayvnc}/bin/wayvnc 0.0.0.0")
            ++ [
              ''
                exec "${pkgs.greetd.gtkgreet}/bin/gtkgreet -l -s /etc/greetd/gtkgreet.css -b ${cfg.wallpaper}; swaymsg exit"
                include /etc/sway/config.d/*
              ''
            ]
            ++ (mapAttrsToList inputStr cfg.input)
            ++ (mapAttrsToList outputStr cfg.output)
          );
          user = "greeter";
          group = "greeter";
        };
        "greetd/environments" = {
          text = concatStringsSep "\n" (
            (optional cfg.sway "${swaySession}")
            ++ (optional cfg.steam "${steam-gamescope}")
            ++ [ "${pkgs.bash}/bin/bash" ]
          );
          user = "greeter";
          group = "greeter";
        };
        "greetd/gtkgreet.css" = {
          text = style;
          user = "greeter";
          group = "greeter";
        };
        "sway/config.d/systemd-env.conf" = {
          text = ''
            exec_always --no-startup-id systemctl --user import-environment ${envVars}
            exec_always --no-startup-id dbus-update-activation-environment --systemd ${envVars}
          '';
        };
        "xdg/gtk-3.0/settings.ini" = {
          text = generators.toINI { } {
            Settings = {
              gtk-theme-name = "elementary";
              gtk-icon-theme-name = "elementary";
              gtk-cursor-theme-name = "elementary";
              gtk-application-prefer-dark-theme = "true";
            };
          };
        };
        "xdg/gtk-4.0/settings.ini" = {
          text = generators.toINI { } {
            Settings = {
              gtk-theme-name = "elementary";
              gtk-icon-theme-name = "elementary";
              gtk-cursor-theme-name = "elementary";
              gtk-application-prefer-dark-theme = "true";
            };
          };
        };
      };
    };
  };
}