dotfiles.nix/home/extras/helix/auto-theme.nix

{
  config,
  pkgs,
  lib,
  ...
}:
let
  cfg = config.programs.helix;
  tomlFormat = pkgs.formats.toml { };
in
{
  options.programs.helix = {
    autoTheme = {
      enable = lib.mkEnableOption "Automatically switch helix theme with night mode";

      light = lib.mkOption {
        type = lib.types.str;
        description = "Light mode theme";
      };

      dark = lib.mkOption {
        type = lib.types.str;
        description = "Dark mode theme";
      };
    };
  };

  config = lib.mkIf (cfg.enable && cfg.autoTheme.enable) {
    xdg.configFile = {
      "helix/light.toml".source = tomlFormat.generate "helix-autotheme" (
        cfg.settings // { theme = cfg.autoTheme.light; }
      );
      "helix/dark.toml".source = tomlFormat.generate "helix-autotheme" (
        cfg.settings // { theme = cfg.autoTheme.dark; }
      );
    };

    programs.fish.functions = {
      hx = {
        wraps = "hx";
        description = "Helix invocation wrapper to automatically select the right theme";
        body = ''
          if is-dark-mode
            command hx --config ${config.xdg.configHome}/helix/dark.toml $argv
          else
            command hx --config ${config.xdg.configHome}/helix/light.toml $argv
          end
        '';
      };
    };
  };
}