defmodule MessengerBot.Component.Message.Attachment do
  @moduledoc """
  Structure and type for attachment
  """

  alias MessengerBot.Component.Message.{ButtonTemplatePayload,
    GenericTemplatePayload, ListTemplatePayload, OpenGraphTemplatePayload}

  @derive [Poison.Encoder]
  defstruct [:type, :payload]

  @type t :: %__MODULE__{
    type: String.t,
    payload: ButtonTemplatePayload.t | GenericTemplatePayload.t |
      ListTemplatePayload.t | Map.t
  }

  @spec button_template(ButtonTemplatePayload.t) :: __MODULE__.t
  def button_template(%ButtonTemplatePayload{} =
    button_template_payload) do
    %__MODULE__{type: "template", payload: button_template_payload}
  end

  @spec generic_template(GenericTemplatePayload.t) :: __MODULE__.t
  def generic_template(%GenericTemplatePayload{} = generic_template_payload) do
    %__MODULE__{type: "template", payload: generic_template_payload}
  end

  @spec open_graph_template(OpenGraphTemplatePayload.t) :: __MODULE__.t
  def open_graph_template(%OpenGraphTemplatePayload{} =
    open_graph_template_payload) do
    %__MODULE__{type: "template", payload: open_graph_template_payload}
  end

  @spec list_template(ListTemplatePayload.t) :: __MODULE__.t
  def list_template(%ListTemplatePayload{} = list_template_payload) do
    %__MODULE__{type: "template", payload: list_template_payload}
  end

  @spec audio_attachment(String.t) :: __MODULE__.t
  def audio_attachment(url) do
    %__MODULE__{type: "audio", payload: %{url: url}}
  end

  @spec file_attachment(String.t) :: __MODULE__.t
  def file_attachment(url) do
    %__MODULE__{type: "file", payload: %{url: url}}
  end

  @spec image_attachment(String.t) :: __MODULE__.t
  def image_attachment(url) do
    %__MODULE__{type: "image", payload: %{url: url}}
  end

  @spec video_attachment(String.t) :: __MODULE__.t
  def video_attachment(url) do
    %__MODULE__{type: "video", payload: %{url: url}}
  end
end