gen_fsm example

gen_fsm_example.ex

defmodule Exflow do

  @behaviour :gen_fsm

  def start_link(code) do
    IO.puts "starting fsm"
    :gen_fsm.start_link({:local, Exflow}, Exflow, :lists.reverse(code), [])
  end

  def button(digit) do
    IO.puts "pushing button #{digit}"
    :gen_fsm.send_event(Exflow, {:button, digit})
  end

  def init(code) do
    IO.puts "fms init"
    {:ok, :locked, {[], code}}
  end

  def get_status() do
    :sys.get_status(Exflow)
  end

  def locked({:button, digit}, {soFar, code}) do
    IO.puts "checking if the device is locked"
    case [digit|soFar] do
      ^code ->
        do_unlock()
        {:next_state, :open, {[], code}, 30000}
      incomplete when length(incomplete)<length(code) ->
        {:next_state, :locked, {incomplete, code}}
      _wrong ->
        {:next_state, :locked, {[], code}}
    end
  end

  def open(:timeout, state) do
    IO.puts "opening device"
    do_lock()
    {:next_state, :locked, state}
  end

  defp do_unlock() do
    IO.puts "unlocking"
  end

  defp do_lock() do
    IO.puts "locking"
  end


  def code_change(oldVsn, stateName, stateData, extra) do
    IO.puts "changing out code"
    new_state_data = ["bar"]
    {:ok, :locked, new_state_data}
  end

  def handle_event(:stop, _state_name, state_data) do
    IO.puts "handling event"
    {:stop, :normal, state_data}
  end

  def handle_info({"EXIT", pid, reason}, state_name, state_data) do
    IO.puts "exiting"
    state_data_1 = ["a", "b", "c"]
    {:exit, :locked, state_data_1}
  end


  def handle_sync_event(a, b, c, d) do
    IO.puts "sync event"
  end

  def terminate(a, b, c) do
    IO.puts "terminating"
    :ok
  end

end