defmodule LightningWeb.UserSocket do
  use Phoenix.Socket

  # A Socket handler
  #
  # It's possible to control the websocket connection and
  # assign values that can be accessed by your channel topics.

  ## Channels

  channel "workflow:*", LightningWeb.WorkflowChannel

  # Socket params are passed from the client and can
  # be used to verify and authenticate a user. After
  # verification, you can put default assigns into
  # the socket that will be set for all channels, ie
  #
  #     {:ok, assign(socket, :user_id, verified_user_id)}
  #
  # To deny connection, return `:error` or `{:error, term}`. To control the
  # response the client receives in that case, [define an error handler in the
  # websocket
  # configuration](https://hexdocs.pm/phoenix/Phoenix.Endpoint.html#socket/3-websocket-configuration).
  #
  # See `Phoenix.Token` documentation for examples in
  # performing token verification on connect.
  @impl true
  def connect(%{"token" => token}, socket, _connect_info) do
    # max_age: 1209600 is equivalent to two weeks in seconds
    case Phoenix.Token.verify(socket, "user socket", token, max_age: 1_209_600) do
      {:ok, user_id} ->
        {:ok,
         assign(socket, :current_user, Lightning.Accounts.get_user(user_id))}

      {:error, _reason} ->
        :error
    end
  end

  # Socket IDs are topics that allow you to identify all sockets for a given user:
  #
  #     def id(socket), do: "user_socket:#{socket.assigns.user_id}"
  #
  # Would allow you to broadcast a "disconnect" event and terminate
  # all active sockets and channels for a given user:
  #
  #     Elixir.LightningWeb.Endpoint.broadcast("user_socket:#{user.id}", "disconnect", %{})
  #
  # Returning `nil` makes this socket anonymous.
  @impl true
  def id(socket), do: "user_socket:#{socket.assigns.current_user.id}"

  def handle_error(conn, :unauthorized) do
    Plug.Conn.send_resp(conn, 401, "Unauthorized")
  end
end
