defmodule Driver8 do
  @moduledoc """

  """
  use GenServer

  @doc """
  Starts a `Driver8` process linked to the current process (to be used as a part of supervision tree).

  Once process is started it will register itself with default name `Driver8`. This name is used by `Driver8.Plug` to
  call for request handling.

  ## Options
     * :name` - value used for name registration, if not passed defaults to `Driver8`
  """
  def start_link(opts) do
    name = Keyword.get(opts, :name, Driver8)
    GenServer.start_link(__MODULE__, [prefix: name], name: name)
  end

  @impl true
  def init(opts) do
    {:ok, supervisor_pid} = DynamicSupervisor.start_link(strategy: :one_for_one)

    prefix = Keyword.get(opts, :prefix, Driver8)
    registry = String.to_atom("#{prefix}.Registry")

    {:ok, _} = Registry.start_link(keys: :unique, name: registry)
    {:ok, [supervisor: supervisor_pid, registry: registry]}
  end

  @impl true
  def handle_cast({:reset_timer, session_id}, state) do
    Driver8.Session.reset_timer(state[:registry], session_id)
    {:noreply, state}
  end

  @impl true
  def handle_call(:is_ready, _from, state) do
    {:reply, true, state}
  end

  @impl true
  def handle_call({:new_session, params}, _from, state) do
    {:reply, Driver8.Session.new(state[:supervisor], state[:registry], params), state}
  end

  @impl true
  def handle_call({:remove_session, session_id}, _from, state) do
    {:reply, Driver8.Session.remove(state[:registry], session_id), state}
  end

  @impl true
  def handle_call({:find_session, session_id}, _from, state) do
    {:reply, Driver8.Session.find(state[:registry], session_id), state}
  end

  @impl true
  def handle_call(request, _from, state) do
    case request do
      {:ext, path, _session_id, _opts} ->
        {:reply,
         {:error,
          "Driver8: Cannot process session level request: #{path |> Enum.join("/")}. Make sure your extension and client library use the same URL",
          request}, state}

      _ ->
        {:reply, {:error, "Driver8: Cannot process request", request}, state}
    end
  end
end