Elixir service module switcher

service_module_switcher.exs

defmodule ServiceSwitcher do
  defmacro __using__(opts \\ []) do
    service_module_mapping = opts[:service_module_mapping]

    quote do
      @service_module_mapping unquote(service_module_mapping)
      @services Keyword.keys(@service_module_mapping)

      def get_service_module(service) when is_binary(service),
        do: service |> String.to_atom() |> get_service_module()

      def get_service_module(service) when service in @services do
        {:ok, @service_module_mapping[service]}
      end

      def get_service_module(_), do: {:error, :no_service_module_for_service}
    end
  end
end

defmodule ServiceOne do
  def execute(params) do
    IO.inspect(params)
    IO.puts("ServiceOne executed")
  end
end

defmodule ServiceTwo do
  def execute(params) do
    IO.inspect(params)
    IO.puts("ServiceTwo executed")
  end
end

defmodule MyService do
  use ServiceSwitcher,
    service_module_mapping: [
      {:service_one, ServiceOne},
      {:service_two, ServiceTwo}
    ]

  def execute(service, params \\ []) do
    with {:ok, service_module} <- get_service_module(service) do
      apply(service_module, :execute, [params])
    end
  end
end

MyService.execute(:service_one, "hello")
MyService.execute("service_one", "hello")

MyService.execute(:service_two, "hello")
MyService.execute("service_two", "hello")