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

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

let
  cfg = config.programs.helix;
  tomlFormat = pkgs.formats.toml { };
  inherit (lib) mkIf mkEnableOption mkOption types;
in {
  options.programs.helix = {
    autoTheme.enable =
      mkEnableOption "Automatically switch helix theme with night mode";

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

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

  config = 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
        '';
      };
    };
  };
}