defmodule Teac.Api.Streams.Followed do
  alias Teac.Api

  @schema NimbleOptions.new!(
            user_id: [type: :string, required: true],
            after: [type: :string],
            first: [type: :pos_integer]
          )

  @doc """
  Gets the list of broadcasters that the user follows and that are streaming live.

  ## Authorization
  Requires a user access token with the `user:read:follows` scope.

  ## Options
  * `:user_id` - required. The ID of the user whose followed streams to get.
  * `:first` - optional. Maximum items to return. Default: 100, max: 100.
  * `:after` - optional. Cursor for forward pagination.
  """
  @spec get(Teac.Client.t(), keyword()) ::
          {:ok, list(map()), String.t() | nil} | {:error, Teac.Error.t()}
  def get(%Teac.Client{} = client, opts \\ []) do
    case NimbleOptions.validate(opts, @schema) do
      {:ok, opts} ->
        params =
          [user_id: opts[:user_id], after: opts[:after], first: opts[:first]]
          |> Enum.reject(fn {_, v} -> is_nil(v) end)

        [base_url: Api.uri("streams/followed"), params: params, headers: Api.headers(client)]
        |> Keyword.merge(Application.get_env(:teac, :api_req_options, []))
        |> Req.get!()
        |> Api.handle_paginated_response()

      {:error, %NimbleOptions.ValidationError{} = err} ->
        {:error, err.message}
    end
  end

  @doc "Streams all followed live streams, automatically following pagination cursors."
  @spec stream(Teac.Client.t(), keyword()) :: Enumerable.t()
  def stream(%Teac.Client{} = client, opts \\ []) do
    Teac.Api.Pagination.stream(client, &get/2, opts)
  end
end