defmodule Grizzly.ZWave.Commands.UserCodeSet do
  @moduledoc """
  UserCodeSet sets the user code

  Params:

    * `:user_id` - the id of the user code (required)
    * `:user_id_status` - the status if the user id slot (required)
    * `:user_code` - a 4 - 10 user code pin in string format (required)
  """

  @behaviour Grizzly.ZWave.Command

  alias Grizzly.ZWave.Command
  alias Grizzly.ZWave.CommandClasses.UserCode

  @type param ::
          {:user_id, byte()}
          | {:user_id_status, UserCode.user_id_status()}
          | {:user_code, String.t()}

  @impl Grizzly.ZWave.Command
  @spec new([param()]) :: {:ok, Command.t()}
  def new(params) do
    command = %Command{
      name: :user_code_set,
      command_byte: 0x01,
      command_class: UserCode,
      params: params,
      impl: __MODULE__
    }

    {:ok, command}
  end

  @impl Grizzly.ZWave.Command
  @spec encode_params(Command.t()) :: binary()
  def encode_params(command) do
    user_id = Command.param!(command, :user_id)
    user_id_status = Command.param!(command, :user_id_status)
    user_code = Command.param!(command, :user_code)

    # CC:0063.01.01.11.009 - The User Code field MUST be set to 0x00000000 (4 bytes)
    # when User ID Status is equal to 0x00 (Available).
    user_code =
      if user_id_status == :available do
        <<0x00, 0x00, 0x00, 0x00>>
      else
        user_code
      end

    <<user_id, UserCode.user_id_status_to_byte(user_id_status)>> <> user_code
  end

  @impl Grizzly.ZWave.Command
  @spec decode_params(binary()) :: {:ok, [param()]}
  def decode_params(<<user_id, user_id_status_byte, user_code_binary::binary>>) do
    {:ok,
     [
       user_id: user_id,
       user_id_status: UserCode.user_id_status_from_byte(user_id_status_byte),
       user_code: user_code_binary
     ]}
  end
end