// Copyright 2024 Matthew Rich <matthewrich.conf@gmail.com>. All rights reserved.
 
package machine

import(
  "log"
  "testing"
	"github.com/stretchr/testify/assert"
)

func setupStater(initial State) Stater {
  s := New(initial)
  if s == nil {
    log.Fatal("Failed creating new Stater")
  }
  return s
}

func TestMachineStater(t *testing.T) {
  s := setupStater("disconnected")

  s.AddStates("disconnected", "start_connection", "connected")
  r := s.GetState("connected")
  if r != "connected" {
    t.Errorf("Failed checking state: %s", r)
  }
}

func TestMachineCurrentState(t *testing.T) {
  s := setupStater("disconnected")

  s.AddStates("disconnected", "start_connection", "connected")
  r := s.CurrentState()
  if r != "disconnected" {
    t.Errorf("Failed checking state: %s", r)
  }
}

func TestMachineAddTransition(t *testing.T) {
  s := setupStater("disconnected")
  s.AddStates("disconnected", "start_connection", "connected")
  s.AddTransition("connect", "disconnected", "start_connection")
  s.AddModel(setupModel("disconnected"))
  // worker gets a trigger message
  assert.Nil(t, s.Trigger("connect"))
	
  // machine generates transition event mesages
  if s.CurrentState() != "start_connection" {
    t.Errorf("State transition failed for: connect - %s", s.CurrentState())
  }
}

func TestMachineAddSubscription(t *testing.T) {
  x := setupSubscriber()
  s := setupStater("disconnected")
  s.AddStates("disconnected", "start_connection", "connected")
  s.AddTransition("connect", "disconnected", "start_connection")
  assert.Nil(t, s.AddSubscription("connect", x))
  s.AddModel(setupModel("disconnected"))
  s.Trigger("connect")
  exitMessage := <- *x.(*EventChannel)
  enterMessage := <- *x.(*EventChannel)
  if exitMessage.on == EXITSTATEEVENT && exitMessage.source == "disconnected" {
    if enterMessage.on == ENTERSTATEEVENT && enterMessage.dest == "start_connection" {
      return
    }
  }
  t.Errorf("Unexpected event message in state transition notification: exit: %s, enter: %s", exitMessage, enterMessage)
}