Twitch build authorization URL

twitch auth.ex

@doc """
  Builds an authorization URL which should be visited by users in order to connect Twitch to your application.

  Reference: https://dev.twitch.tv/docs/authentication/getting-tokens-oauth/#implicit-grant-flow
  """
  @spec build_authorization_url(
          client_id :: String.t(),
          redirect_uri :: String.t(),
          scopes :: list(Scope.t())
        ) :: String.t()
  @spec build_authorization_url(
          client_id :: String.t(),
          redirect_uri :: String.t(),
          scopes :: list(Scope.t()),
          opts :: Keyword.t()
        ) :: String.t()
  def build_authorization_url(client_id, redirect_uri, scopes, opts \\ []) do
    response_type = Keyword.get(opts, :response_type, :code)
    state = Keyword.get(opts, :state)
    force_verify = Keyword.get(opts, :force_verify, false)

    query_params = %{
      "response_type" => response_type,
      "client_id" => client_id,
      "redirect_uri" => redirect_uri,
      "scope" => Enum.join(scopes, " "),
      "force_verify" => force_verify
    }

    query_params_with_state =
      if state != nil do
        Map.put(query_params, "state", state)
      else
        query_params
      end

    "https://id.twitch.tv/oauth2/authorize"
    |> URI.new!()
    |> URI.append_query(URI.encode_query(query_params_with_state))
    |> URI.to_string()
  end