defmodule Slack.User do
  @moduledoc ~S"""
  A Slack user.
  """

  @typedoc @moduledoc
  @type t :: %__MODULE__{
          id: String.t(),
          name: String.t()
        }

  @enforce_keys [
    :id,
    :name
  ]
  defstruct @enforce_keys

  @doc ~S"""
  Parse Slack user.
  """
  @spec parse(map) :: {:ok, t} | {:error, :user_missing_id | :user_missing_name | :invalid_user}
  def parse(data = %{}) do
    id = MapX.get(data, :id)
    name = MapX.get(data, :name)

    cond do
      is_nil(id) -> {:error, :user_missing_id}
      is_nil(name) -> {:error, :user_missing_name}
      :valid -> {:ok, %__MODULE__{id: id, name: name}}
    end
  end

  def parse(_), do: {:error, :invalid_user}
end