home-manager/modules/services/cbatticon.nix

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

with lib;

let

  cfg = config.services.cbatticon;

  package = pkgs.cbatticon;

  makeCommand = commandName: commandArg:
    optional (commandArg != null) (
      let
        cmd = pkgs.writeShellScript commandName commandArg;
      in
        "--${commandName} ${cmd}"
    );

  commandLine = concatStringsSep " " (
    [ "${package}/bin/cbatticon" ]
    ++ makeCommand "command-critical-level" cfg.commandCriticalLevel
    ++ makeCommand "command-left-click" cfg.commandLeftClick
    ++ optional
      (cfg.iconType != null)
      "--icon-type ${cfg.iconType}"
    ++ optional
      (cfg.lowLevelPercent != null)
      "--low-level ${toString cfg.lowLevelPercent}"
    ++ optional
      (cfg.criticalLevelPercent != null)
      "--critical-level ${toString cfg.criticalLevelPercent}"
    ++ optional
      (cfg.updateIntervalSeconds != null)
      "--update-interval ${toString cfg.updateIntervalSeconds}"
    ++ optional
      (cfg.hideNotification != null && cfg.hideNotification)
      "--hide-notification"
  );

in

{
  meta.maintainers = [ maintainers.pmiddend ];

  options = {
    services.cbatticon = {
      enable = mkEnableOption "cbatticon";

      commandCriticalLevel = mkOption {
        type = types.nullOr types.lines;
        default = null;
        example = ''
          notify-send "battery critical!"
        '';
        description = ''
          Command to execute when the critical battery level is reached.
        '';
      };

      commandLeftClick = mkOption {
        type = types.nullOr types.lines;
        default = null;
        description = ''
          Command to execute when left clicking on the tray icon.
        '';
      };

      iconType = mkOption {
        type = types.nullOr (types.enum [ "standard" "notification" "symbolic" ]);
        default = null;
        example = "symbolic";
        description = "Icon type to display in the system tray.";
      };

      lowLevelPercent = mkOption {
        type = types.nullOr (types.ints.between 0 100);
        default = null;
        example = 20;
        description = ''
          Low level percentage of the battery in percent (without the
          percent symbol).
        '';
      };

      criticalLevelPercent = mkOption {
        type = types.nullOr (types.ints.between 0 100);
        default = null;
        example = 5;
        description = ''
          Critical level percentage of the battery in percent (without
          the percent symbol).
        '';
      };

      updateIntervalSeconds = mkOption {
        type = types.nullOr types.ints.positive;
        default = null;
        example = 5;
        description = ''
          Number of seconds between updates of the battery information.
        '';
      };

      hideNotification = mkOption {
        type = types.nullOr types.bool;
        default = null;
        description = "Hide the notification popups.";
      };
    };
  };

  config = mkIf cfg.enable {
    home.packages = [ package ];

    systemd.user.services.cbatticon = {
      Unit = {
        Description = "cbatticon system tray battery icon";
        After = [ "graphical-session-pre.target" ];
        PartOf = [ "graphical-session.target" ];
      };

      Install = {
        WantedBy = [ "graphical-session.target" ];
      };

      Service = {
        ExecStart = commandLine;
        Restart = "on-abort";
      };
    };
  };
}