self:
{
  config,
  lib,
  pkgs,
  ...
}:
let
  cfg = config.programs.nova-shell;
in
{
  options.programs.nova-shell = {
    enable = lib.mkEnableOption "nova-shell Quickshell bar";

    package = lib.mkOption {
      type = lib.types.package;
      default = self.packages.${pkgs.stdenv.hostPlatform.system}.default;
      description = "nova-shell package to use.";
    };

    modules =
      let
        moduleOpt =
          name: extra:
          lib.mkOption {
            default = { };
            description = "Configuration for the ${name} module.";
            type = lib.types.submodule {
              options = {
                enable = lib.mkOption {
                  type = lib.types.bool;
                  default = true;
                  description = "Enable the ${name} module.";
                };
              }
              // extra;
            };
          };
        intervalOpt = default: {
          interval = lib.mkOption {
            type = lib.types.int;
            inherit default;
            description = "Polling interval in milliseconds.";
          };
        };
        simpleModules = lib.genAttrs [
          "workspaces"
          "tray"
          "windowTitle"
          "clock"
          "mpris"
          "volume"
          "bluetooth"
          "network"
          "powerProfile"
          "cpu"
          "memory"
          "idleInhibitor"
          "privacy"
          "screenCorners"
          "power"
          "backgroundOverlay"
          "overviewBackdrop"
        ] (name: moduleOpt name { });
      in
      simpleModules
      // {
        lock = moduleOpt "lock" {
          screenshot = lib.mkOption {
            type = lib.types.bool;
            default = true;
            description = "Show blurred desktop screenshot as lock screen background.";
          };
          notifications = lib.mkOption {
            type = lib.types.bool;
            default = true;
            description = "Show notification app icons on the lock screen.";
          };
          mpris = lib.mkOption {
            type = lib.types.bool;
            default = true;
            description = "Show media controls on the lock screen.";
          };
          volume = lib.mkOption {
            type = lib.types.bool;
            default = true;
            description = "Show volume slider on the lock screen.";
          };
          weather = lib.mkOption {
            type = lib.types.bool;
            default = true;
            description = "Show weather summary on the lock screen.";
          };
          threatEffect = lib.mkOption {
            type = lib.types.bool;
            default = true;
            description = "Show red vignette and chromatic aberration on failed password attempts.";
          };
        };
        notifications = moduleOpt "notifications" {
          timeout = lib.mkOption {
            type = lib.types.int;
            default = 3000;
            description = "Notification popup timeout in milliseconds.";
          };
          maxPopups = lib.mkOption {
            type = lib.types.int;
            default = 4;
            description = "Maximum number of notification popups shown simultaneously.";
          };
          maxVisible = lib.mkOption {
            type = lib.types.int;
            default = 10;
            description = "Maximum visible notifications in the notification center before scrolling.";
          };
          maxHistory = lib.mkOption {
            type = lib.types.int;
            default = -1;
            description = "Maximum notifications kept in history (-1 for unlimited).";
          };
        };
        disk = moduleOpt "disk" (
          (intervalOpt 30000)
          // {
            warnThreshold = lib.mkOption {
              type = lib.types.int;
              default = 85;
              description = "Usage percentage at which the disk module bar turns warning color.";
            };
          }
        );
        backlight = moduleOpt "backlight" {
          step = lib.mkOption {
            type = lib.types.int;
            default = 5;
            description = "Brightness adjustment step (%).";
          };
        };
        gpu = moduleOpt "gpu" {
          warm = lib.mkOption {
            type = lib.types.int;
            default = 70;
            description = "GPU temperature threshold for warm state (°C).";
          };
          hot = lib.mkOption {
            type = lib.types.int;
            default = 85;
            description = "GPU temperature threshold for hot state (°C).";
          };
        };
        temperature = moduleOpt "temperature" {
          warm = lib.mkOption {
            type = lib.types.int;
            default = 80;
            description = "Temperature threshold for warm state (°C).";
          };
          hot = lib.mkOption {
            type = lib.types.int;
            default = 90;
            description = "Temperature threshold for hot state (°C).";
          };
          device = lib.mkOption {
            type = lib.types.str;
            default = "";
            description = ''
              Thermal zone device name to use for the primary temperature reading
              (e.g. "x86_pkg_temp", "acpitz"). Leave empty to use the system maximum.
            '';
          };
        };
        battery = moduleOpt "battery" {
          warning = lib.mkOption {
            type = lib.types.int;
            default = 25;
            description = "Battery percentage for warning notification.";
          };
          critical = lib.mkOption {
            type = lib.types.int;
            default = 15;
            description = "Battery percentage for critical notification and blink.";
          };
          poweralertd = lib.mkOption {
            type = lib.types.bool;
            default = true;
            description = "Enable poweralertd for battery/power event notifications. Set to false to disable.";
          };
        };
        weather = moduleOpt "weather" (
          (intervalOpt 3600000)
          // {
            args = lib.mkOption {
              type = lib.types.listOf lib.types.str;
              default = [ "--nerd" ];
              description = "Arguments passed to wttrbar.";
              example = [
                "--nerd"
                "--location"
                "Berlin"
              ];
            };
          }
        );
        dock = moduleOpt "dock" {
          width = lib.mkOption {
            type = lib.types.int;
            default = 300;
            description = "Dock panel width in pixels.";
          };
          applets = lib.mkOption {
            default = { };
            description = "Per-applet enable flags for the dock (independent from bar modules).";
            type = lib.types.submodule {
              options =
                lib.genAttrs
                  [
                    "clock"
                    "cpu"
                    "gpu"
                    "memory"
                    "temperature"
                    "disk"
                    "battery"
                    "network"
                    "bluetooth"
                    "volume"
                    "backlight"
                    "weather"
                    "mpris"
                    "notifications"
                    "power"
                  ]
                  (
                    name:
                    lib.mkOption {
                      type = lib.types.bool;
                      default = true;
                      description = "Show ${name} applet in the dock.";
                    }
                  );
            };
          };
        };
        statsDaemon = lib.mkOption {
          default = { };
          description = "Configuration for the nova-stats daemon.";
          type = lib.types.submodule {
            options.interval = lib.mkOption {
              type = lib.types.int;
              default = -1;
              description = "nova-stats polling interval in milliseconds (-1 = use binary default of 1s).";
            };
          };
        };
      };

    theme = lib.mkOption {
      type = lib.types.attrsOf lib.types.anything;
      default = { };
      description = ''
        Theme overrides written to `$XDG_CONFIG_HOME/nova-shell/theme.json`.
        Keys: colors (base00-base0F), fontFamily, iconFontFamily, fontSize,
        barOpacity, barHeight, barPadding, groupSpacing, groupPadding, moduleSpacing,
        radius, screenRadius, reducedMotion.
        Populated from stylix when homeModules.stylix is imported.
      '';
    };

    systemd = {
      enable = lib.mkOption {
        type = lib.types.bool;
        default = true;
        description = "Run nova-shell as a systemd user service.";
      };
      target = lib.mkOption {
        type = lib.types.str;
        default = "graphical-session.target";
        description = "Systemd target to bind the service to.";
      };
    };
  };

  config = lib.mkIf cfg.enable {
    home.packages = [
      cfg.package
      pkgs.nerd-fonts.symbols-only
    ]
    ++ lib.optional cfg.modules.weather.enable pkgs.wttrbar
    ++ lib.optional cfg.modules.mpris.enable pkgs.cava
    ++ lib.optional cfg.modules.disk.enable pkgs.coreutils;

    xdg.configFile."nova-shell/modules.json".source =
      (pkgs.formats.json { }).generate "nova-shell-modules.json"
        cfg.modules;

    xdg.configFile."nova-shell/theme.json".source =
      (pkgs.formats.json { }).generate "nova-shell-theme.json"
        cfg.theme;

    # Niri layer rules for backdrop placement (requires niri-flake hm module)
    programs.niri.settings.layer-rules = lib.mkIf (config ? programs && config.programs ? niri) [
      {
        matches = [ { namespace = "^nova-overview-backdrop$"; } ];
        place-within-backdrop = true;
      }
    ];

    services.poweralertd.enable = lib.mkIf (
      cfg.modules.battery.enable && cfg.modules.battery.poweralertd
    ) (lib.mkDefault true);

    systemd.user.services.nova-shell = lib.mkIf cfg.systemd.enable {
      Unit = {
        Description = "nova-shell Quickshell bar";
        PartOf = [ cfg.systemd.target ];
        After = [ cfg.systemd.target ];
        StartLimitIntervalSec = 30;
        StartLimitBurst = 5;
      };
      Service = {
        ExecStart = lib.getExe cfg.package;
        Restart = "always";
        RestartSec = 1;
        Slice = "session.slice";
      };
      Install.WantedBy = [ cfg.systemd.target ];
    };
  };
}