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

package machine

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

func setupTransition() Transitioner {
	t := NewTransition("open", States("closed"), "open")
	if t == nil {
		log.Fatal("Failed creating new transition")
	}
	return t
}

func setupSubscriber() Subscriber {
	c := make(EventChannel, 2)
	return &c
}

func TestNewTransition(t *testing.T) {
	s := NewTransition("connect", States("disconnected"), "connected")
	if s == nil {
		t.Errorf("Failed creating new transition")
	}
}

func TestTransitionExecution(t *testing.T) {
	s := setupTransition()
	m := setupModel("closed")
	assert.Nil(t, s.Run(m))
	state := m.InspectState()
	if state != "open" {
		t.Errorf("Failed to transition state: %s", state)
	}
}

func TestTransitionWildcard(t *testing.T) {
	tr := NewTransition("open", States("*"), "opened")
	assert.NotNil(t, tr)
	m := setupModel("closed")
	assert.Nil(t, tr.Run(m))
	assert.Equal(t, "opened", string(m.InspectState()))
}

func TestTransitionSubscribe(t *testing.T) {
	c := setupSubscriber()
	s := setupTransition()
	s.Subscribe(c)
	m := setupModel("closed")
	assert.Nil(t, s.Run(m))
	exitEvent := <-*c.(*EventChannel)
	enterEvent := <-*c.(*EventChannel)
	if exitEvent.On != EXITSTATEEVENT {
		t.Errorf("Invalid exit event")
	}
	if enterEvent.On != ENTERSTATEEVENT {
		t.Errorf("Invalid enter event")
	}
}

func TestTransitionMultipleSourceStates(t *testing.T) {
	tr := NewTransition("open", States("closed", "disconnected"), "opened")
	assert.NotNil(t, tr)
	mc := setupModel("closed")
	assert.Nil(t, tr.Run(mc))
	assert.Equal(t, "opened", string(mc.InspectState()))
	md := setupModel("disconnected")
	assert.Nil(t, tr.Run(md))
	assert.Equal(t, "opened", string(md.InspectState()))
}