# encoding: utf-8

require "logger"
require "thread"
require "sync"
require "forwardable"

require "finite_machine/version"
require "finite_machine/threadable"
require "finite_machine/safety"
require "finite_machine/thread_context"
require "finite_machine/callable"
require "finite_machine/catchable"
require "finite_machine/choice_merger"
require "finite_machine/async_proxy"
require "finite_machine/async_call"
require "finite_machine/hook_event"
require "finite_machine/event"
require "finite_machine/event_builder"
require "finite_machine/event_queue"
require "finite_machine/events_chain"
require "finite_machine/hooks"
require "finite_machine/logger"
require "finite_machine/transition"
require "finite_machine/transition_builder"
require "finite_machine/transition_event"
require "finite_machine/dsl"
require "finite_machine/definition"
require "finite_machine/state_machine"
require "finite_machine/subscribers"
require "finite_machine/state_parser"
require "finite_machine/observer"
require "finite_machine/listener"
require "finite_machine/two_phase_lock"

module FiniteMachine
  # Default state name
  DEFAULT_STATE = :none

  # Initial default event name
  DEFAULT_EVENT_NAME = :init

  # Describe any state transition
  ANY_STATE = :any

  # Describe any event name
  ANY_EVENT = :any_event

  # Returned when transition has successfully performed
  SUCCEEDED = 1

  # Returned when transition is cancelled in callback
  CANCELLED = 2

  # Returned when transition has not changed the state
  NOTRANSITION = 3

  # When transition between states is invalid
  TransitionError = Class.new(::StandardError)

  # Raised when transitining to invalid state
  InvalidStateError = Class.new(::ArgumentError)

  InvalidEventError = Class.new(::NoMethodError)

  # Raised when a callback is defined with invalid name
  InvalidCallbackNameError = Class.new(::StandardError)

  # Raised when event has no transitions
  NotEnoughTransitionsError = Class.new(::ArgumentError)

  # Raised when initial event specified without state name
  MissingInitialStateError = Class.new(::StandardError)

  # Raised when event queue is already dead
  EventQueueDeadError = Class.new(::StandardError)

  # Raised when argument is already defined
  AlreadyDefinedError = Class.new(::ArgumentError)

  Environment = Struct.new(:target, :aliases)

  class << self
    attr_accessor :logger

    # TODO: this should instantiate system not the state machine
    # and then delegate calls to StateMachine instance etc...
    #
    # @example
    #   FiniteMachine.define do
    #     ...
    #   end
    #
    # @return [FiniteMachine::StateMachine]
    #
    # @api public
    def define(*args, &block)
      StateMachine.new(*args, &block)
    end
    alias_method :new, :define
  end
end # FiniteMachine

FiniteMachine.logger = Logger.new(STDERR)