nixpkgs/nixos/modules/services/desktop-managers/cosmic.nix

# SPDX-License-Identifier: MIT
# SPDX-FileCopyrightText: Lily Foster <lily@lily.flowers>
# Portions of this code are adapted from nixos-cosmic
# https://github.com/lilyinstarlight/nixos-cosmic

{
  config,
  lib,
  pkgs,
  utils,
  ...
}:

let
  cfg = config.services.desktopManager.cosmic;
  # **ONLY ADD PACKAGES WITHOUT WHICH COSMIC CRASHES, NOTHING ELSE**
  corePkgs =
    with pkgs;
    [
      cosmic-applets
      cosmic-applibrary
      cosmic-bg
      cosmic-comp
      cosmic-files
      config.services.displayManager.cosmic-greeter.package
      cosmic-idle
      cosmic-launcher
      cosmic-notifications
      cosmic-osd
      cosmic-panel
      cosmic-session
      cosmic-settings
      cosmic-settings-daemon
      cosmic-workspaces-epoch
    ]
    ++ lib.optionals cfg.xwayland.enable [
      # Why would you want to enable XWayland but exclude the package
      # providing XWayland support? Doesn't make sense. Add `xwayland` to the
      # `corePkgs` list.
      xwayland
    ];
in
{
  meta.maintainers = lib.teams.cosmic.members;

  options = {
    services.desktopManager.cosmic = {
      enable = lib.mkEnableOption "Enable the COSMIC desktop environment";

      xwayland.enable = lib.mkEnableOption "Xwayland support for the COSMIC compositor" // {
        default = true;
      };
    };

    environment.cosmic.excludePackages = lib.mkOption {
      description = "List of packages to exclude from the COSMIC environment.";
      type = lib.types.listOf lib.types.package;
      default = [ ];
      example = lib.literalExpression "[ pkgs.cosmic-player ]";
    };
  };

  config = lib.mkIf cfg.enable {
    # Environment packages
    environment.pathsToLink = [
      "/share/backgrounds"
      "/share/cosmic"
    ];
    environment.systemPackages = utils.removePackagesByName (
      corePkgs
      ++ (
        with pkgs;
        [
          adwaita-icon-theme
          alsa-utils
          cosmic-edit
          cosmic-icons
          cosmic-player
          cosmic-randr
          cosmic-screenshot
          cosmic-term
          cosmic-wallpapers
          hicolor-icon-theme
          playerctl
          pop-icon-theme
          pop-launcher
          xdg-user-dirs
        ]
        ++ lib.optionals config.services.flatpak.enable [
          # User may have Flatpaks enabled but might not want the `cosmic-store` package.
          cosmic-store
        ]
      )
    ) config.environment.cosmic.excludePackages;

    # Distro-wide defaults for graphical sessions
    services.graphical-desktop.enable = true;

    xdg = {
      icons.fallbackCursorThemes = lib.mkDefault [ "Cosmic" ];

      portal = {
        enable = true;
        extraPortals = with pkgs; [
          xdg-desktop-portal-cosmic
          xdg-desktop-portal-gtk
        ];
        configPackages = lib.mkDefault [ pkgs.xdg-desktop-portal-cosmic ];
      };
    };

    systemd = {
      packages = [ pkgs.cosmic-session ];
      user.targets = {
        # TODO: remove when upstream has XDG autostart support
        cosmic-session = {
          wants = [ "xdg-desktop-autostart.target" ];
          before = [ "xdg-desktop-autostart.target" ];
        };
      };
    };

    fonts.packages = with pkgs; [
      fira
      noto-fonts
      open-sans
    ];

    # Required options for the COSMIC DE
    environment.sessionVariables.X11_BASE_RULES_XML = "${config.services.xserver.xkb.dir}/rules/base.xml";
    environment.sessionVariables.X11_EXTRA_RULES_XML = "${config.services.xserver.xkb.dir}/rules/base.extras.xml";
    programs.dconf.enable = true;
    programs.dconf.packages = [ pkgs.cosmic-session ];
    security.polkit.enable = true;
    security.rtkit.enable = true;
    services.accounts-daemon.enable = true;
    services.displayManager.sessionPackages = [ pkgs.cosmic-session ];
    services.geoclue2.enable = true;
    services.geoclue2.enableDemoAgent = false;
    services.libinput.enable = true;
    services.upower.enable = true;
    # Required for screen locker
    security.pam.services.cosmic-greeter = { };

    # Good to have defaults
    hardware.bluetooth.enable = lib.mkDefault true;
    networking.networkmanager.enable = lib.mkDefault true;
    services.acpid.enable = lib.mkDefault true;
    services.avahi.enable = lib.mkDefault true;
    services.gnome.gnome-keyring.enable = lib.mkDefault true;
    services.gvfs.enable = lib.mkDefault true;
    services.power-profiles-daemon.enable = lib.mkDefault (
      !config.hardware.system76.power-daemon.enable
    );
  };
}