defmodule Phoenix.SessionProcess do
  @moduledoc """
  Documentation for `Phoenix.SessionProcess`.

  Add superviser to process tree

      [
        ...
        {Phoenix.SessionProcess.Supervisor, []}
      ]

  Add this after the `:fetch_session` plug to generate a unique session ID.

      plug :fetch_session
      plug Phoenix.SessionProcess.SessionId

  Start a session process with a session ID.

      Phoenix.SessionProcess.start("session_id")

  This will start a session process using the module defined with

      config :phoenix_session_process, session_process: MySessionProcess

  Or you can start a session process with a specific module.

      Phoenix.SessionProcess.start("session_id", MySessionProcess)
      # or
      Phoenix.SessionProcess.start("session_id", MySessionProcess, arg)

  Check if a session process is started.

      Phoenix.SessionProcess.started?("session_id")

  Terminate a session process.

      Phoenix.SessionProcess.terminate("session_id")

  Genserver call on a session process.

      Phoenix.SessionProcess.call("session_id", request)

  Genserver cast on a session process.

      Phoenix.SessionProcess.cast("session_id", request)
  """

  @spec start(binary()) :: :ignore | {:error, any()} | {:ok, pid()} | {:ok, pid(), any()}
  defdelegate start(session_id), to: Phoenix.SessionProcess.ProcessSupervisor, as: :start_session
  @spec start(binary(), atom()) :: :ignore | {:error, any()} | {:ok, pid()} | {:ok, pid(), any()}
  defdelegate start(session_id, module), to: Phoenix.SessionProcess.ProcessSupervisor, as: :start_session
  @spec start(binary(), atom(), any()) ::
          :ignore | {:error, any()} | {:ok, pid()} | {:ok, pid(), any()}
  defdelegate start(session_id, module, arg), to: Phoenix.SessionProcess.ProcessSupervisor, as: :start_session

  @spec started?(binary()) :: boolean()
  defdelegate started?(session_id), to: Phoenix.SessionProcess.ProcessSupervisor, as: :session_process_started?

  @spec terminate(binary()) :: :ok | {:error, :not_found}
  defdelegate terminate(session_id), to: Phoenix.SessionProcess.ProcessSupervisor, as: :terminate_session

  @spec call(binary(), any(), :infinity | non_neg_integer()) :: any()
  defdelegate call(session_id, request, timeout \\ 15_000), to: Phoenix.SessionProcess.ProcessSupervisor, as: :call_on_session

  @spec cast(binary(), any()) :: :ok
  defdelegate cast(session_id, request), to: Phoenix.SessionProcess.ProcessSupervisor, as: :cast_on_session


  defmacro __using__(:process) do
    quote do
      use GenServer

      def start_link(name: name, arg: arg) do
        GenServer.start_link(__MODULE__, arg, name: name)
      end
      def start_link(name: name) do
        GenServer.start_link(__MODULE__, %{}, name: name)
      end
    end
  end
end