{
  config,
  lib,
  pkgs,
  dots,
  ...
}:
{
  options.custom = with lib; {
    shell = {
      packages = mkOption {
        type =
          with types;
          attrsOf (oneOf [
            str
            attrs
            package
          ]);
        default = { };
        apply = custom.mkShellPackages;
        description = ''
          Attrset of shell packages to install and add to pkgs.custom overlay (for compatibility across multiple shells).
          Both string and attr values will be passed as arguments to writeShellApplicationCompletions
        '';
        example = ''
          shell.packages = {
            myPackage1 = "echo 'Hello, World!'";
            myPackage2 = {
              runtimeInputs = [ pkgs.hello ];
              text = "hello --greeting 'Hi'";
            };
          }
        '';
      };
      # additionalSourceFile = mkOption {
      #   type =
      #     with types;
      #     nullOr (oneOf [
      #       path
      #       str
      #     ]);
      #   default = "${dots}/src/home/shell/custom.sh";
      # };
    };
  };

  config = {
    # programs.bash = lib.mkIf (config.custom.shell.additionalSourceFile != null) {
    #   bashrcExtra = lib.mkAfter ''
    #     source ${config.custom.shell.additionalSourceFile}
    #   '';
    # };
    # programs.zsh = lib.mkIf (config.custom.shell.additionalSourceFile != null) {
    #   initExtra = lib.mkAfter ''
    #     source ${config.custom.shell.additionalSourceFile}
    #   '';
    # };
  };
}