package eventbus

import (
	"sync"
	"testing"
	"time"

	"github.com/stretchr/testify/assert"
)

func busHandlerOne(topic string, val int) {
}

func busHandlerTwo(topic string, val int) {
}

func Test_newChannel(t *testing.T) {
	ch := newChannel("test_topic", -1)
	assert.NotNil(t, ch)
	assert.NotNil(t, ch.channel)
	assert.Equal(t, "test_topic", ch.topic)
	assert.NotNil(t, ch.stopCh)
	assert.NotNil(t, ch.handlers)
	ch.close()

	bufferedCh := newChannel("test_topic", 100)
	assert.NotNil(t, bufferedCh)
	assert.NotNil(t, bufferedCh.channel)
	assert.Equal(t, 100, cap(bufferedCh.channel))
	assert.Equal(t, "test_topic", bufferedCh.topic)
	assert.NotNil(t, bufferedCh.stopCh)
	assert.NotNil(t, bufferedCh.handlers)
	bufferedCh.close()

	bufferedZeroCh := newChannel("test_topic", 0)
	assert.NotNil(t, bufferedZeroCh)
	assert.NotNil(t, bufferedZeroCh.channel)
	assert.Equal(t, "test_topic", bufferedZeroCh.topic)
	assert.NotNil(t, bufferedZeroCh.stopCh)
	assert.NotNil(t, bufferedZeroCh.handlers)
	bufferedZeroCh.close()
}

func Test_channelSubscribe(t *testing.T) {
	ch := newChannel("test_topic", -1)
	assert.NotNil(t, ch)
	assert.NotNil(t, ch.channel)
	assert.Equal(t, "test_topic", ch.topic)

	err := ch.subscribe(busHandlerOne)
	assert.Nil(t, err)
	ch.close()
	err = ch.subscribe(busHandlerTwo)
	assert.Equal(t, ErrChannelClosed, err)
}

func Test_channelUnsubscribe(t *testing.T) {
	ch := newChannel("test_topic", -1)
	assert.NotNil(t, ch)
	assert.NotNil(t, ch.channel)
	assert.Equal(t, "test_topic", ch.topic)

	err := ch.subscribe(busHandlerOne)
	assert.Nil(t, err)
	err = ch.unsubscribe(busHandlerOne)
	assert.Nil(t, err)

	err = ch.subscribe(busHandlerOne)
	assert.Nil(t, err)
	ch.close()
	err = ch.unsubscribe(busHandlerTwo)
	assert.Equal(t, ErrChannelClosed, err)
}

func Test_channelClose(t *testing.T) {
	ch := newChannel("test_topic", -1)
	assert.NotNil(t, ch)
	assert.NotNil(t, ch.channel)
	assert.Equal(t, "test_topic", ch.topic)

	err := ch.subscribe(busHandlerOne)
	assert.Nil(t, err)
	ch.close()
	assert.Equal(t, uint32(0), ch.handlers.Len())
	ch.close()
}

func Test_channelPublish(t *testing.T) {
	ch := newChannel("test_topic", -1)
	assert.NotNil(t, ch)
	assert.NotNil(t, ch.channel)
	assert.Equal(t, "test_topic", ch.topic)
	ch.subscribe(busHandlerOne)

	var wg sync.WaitGroup
	wg.Add(1)

	go func() {
		for i := 0; i < 100; i++ {
			err := ch.publish(i)
			assert.Nil(t, err)
		}
		wg.Done()
	}()
	wg.Wait()

	err := ch.publish(nil)
	assert.Nil(t, err)
	time.Sleep(time.Millisecond)
	ch.close()
	err = ch.publish(1)
	assert.Equal(t, ErrChannelClosed, err)
}

func Test_channelPublishSync(t *testing.T) {
	ch := newChannel("test_topic", -1)
	assert.NotNil(t, ch)
	assert.NotNil(t, ch.channel)
	assert.Equal(t, "test_topic", ch.topic)
	ch.subscribe(busHandlerOne)

	var wg sync.WaitGroup
	wg.Add(1)

	go func() {
		for i := 0; i < 100; i++ {
			err := ch.publish(i)
			assert.Nil(t, err)
		}
		wg.Done()
	}()
	wg.Wait()

	err := ch.publishSync(nil)
	assert.Nil(t, err)
	time.Sleep(time.Millisecond)
	ch.close()
	err = ch.publishSync(1)
	assert.Equal(t, ErrChannelClosed, err)
}

func Test_New(t *testing.T) {
	bus := New()
	assert.NotNil(t, bus)
	assert.Equal(t, -1, bus.bufferSize)
	assert.NotNil(t, bus.channels)
	bus.Close()
}

func Test_NewBuffered(t *testing.T) {
	bus := NewBuffered(100)
	assert.NotNil(t, bus)
	assert.Equal(t, 100, bus.bufferSize)
	assert.NotNil(t, bus.channels)
	bus.Close()

	busZero := NewBuffered(0)
	assert.NotNil(t, busZero)
	assert.Equal(t, 1, busZero.bufferSize)
	assert.NotNil(t, busZero.channels)
	busZero.Close()
}

func Test_EventBusSubscribe(t *testing.T) {
	bus := New()
	assert.NotNil(t, bus)
	assert.Equal(t, -1, bus.bufferSize)
	assert.NotNil(t, bus.channels)

	err := bus.Subscribe("testtopic", busHandlerOne)
	assert.Nil(t, err)
	err = bus.Subscribe("testtopic", 1)
	assert.Equal(t, ErrHandlerIsNotFunc, err)

	err = bus.Subscribe("testtopic", func(topic string) error {
		return nil
	})
	assert.Equal(t, ErrHandlerParamNum, err)

	err = bus.Subscribe("testtopic", func(topic int, payload int) error {
		return nil
	})
	assert.Equal(t, ErrHandlerFirstParam, err)
	bus.Close()

	err = bus.Unsubscribe("testtopic", busHandlerTwo)
	assert.Equal(t, ErrChannelClosed, err)
}

func Test_EventBusUnsubscribe(t *testing.T) {
	bus := New()
	assert.NotNil(t, bus)
	assert.Equal(t, -1, bus.bufferSize)
	assert.NotNil(t, bus.channels)

	err := bus.Unsubscribe("testtopic", busHandlerOne)
	assert.Equal(t, ErrNoSubscriber, err)

	err = bus.Subscribe("testtopic", busHandlerOne)
	assert.Nil(t, err)

	err = bus.Unsubscribe("testtopic", busHandlerOne)
	assert.Nil(t, err)
	bus.Close()

	err = bus.Unsubscribe("testtopic", busHandlerTwo)
	assert.Equal(t, ErrChannelClosed, err)
}

func Test_EventBusPublish(t *testing.T) {
	bus := New()
	assert.NotNil(t, bus)
	assert.Equal(t, -1, bus.bufferSize)
	assert.NotNil(t, bus.channels)

	err := bus.Publish("testtopic", 1)
	assert.Nil(t, err)

	err = bus.Subscribe("testtopic", busHandlerOne)
	assert.Nil(t, err)

	var wg sync.WaitGroup
	wg.Add(1)
	go func() {
		for i := 0; i < 100; i++ {
			err := bus.Publish("testtopic", i)
			assert.Nil(t, err)
		}
		wg.Done()
	}()
	wg.Wait()
	bus.Close()
}

func Test_EventBusPublishSync(t *testing.T) {
	bus := New()
	assert.NotNil(t, bus)
	assert.Equal(t, -1, bus.bufferSize)
	assert.NotNil(t, bus.channels)

	err := bus.PublishSync("testtopic", 1)
	assert.Nil(t, err)

	err = bus.Subscribe("testtopic", busHandlerOne)
	assert.Nil(t, err)

	var wg sync.WaitGroup
	wg.Add(1)
	go func() {
		for i := 0; i < 100; i++ {
			err := bus.PublishSync("testtopic", i)
			assert.Nil(t, err)
		}
		wg.Done()
	}()
	wg.Wait()
	bus.Close()
}

func BenchmarkEventBusPublish(b *testing.B) {
	bus := New()
	bus.Subscribe("testtopic", busHandlerOne)

	b.ResetTimer()
	var wg sync.WaitGroup
	wg.Add(1)
	go func() {
		for i := 0; i < b.N; i++ {
			bus.Publish("testtopic", i)
		}
		wg.Done()
	}()
	wg.Wait()
	bus.Close()
}

func BenchmarkEventBusPublishSync(b *testing.B) {
	bus := New()
	bus.Subscribe("testtopic", busHandlerOne)

	b.ResetTimer()
	var wg sync.WaitGroup
	wg.Add(1)
	go func() {
		for i := 0; i < b.N; i++ {
			bus.PublishSync("testtopic", i)
		}
		wg.Done()
	}()
	wg.Wait()
	bus.Close()
}