package msgbus

import (
	"bytes"
	"context"
	"encoding/json"
	"flag"
	"io/ioutil"
	"net/http"
	"net/http/httptest"
	"os"
	"testing"

	log "github.com/sirupsen/logrus"
	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"
	"nhooyr.io/websocket"
	"nhooyr.io/websocket/wsjson"
)

var (
	debug = flag.Bool("d", false, "enable debug logging")
)

func TestMessageBusLen(t *testing.T) {
	assert := assert.New(t)
	require := require.New(t)

	testdir, err := ioutil.TempDir("", "msgbus-logs-*")
	require.NoError(err)
	defer os.RemoveAll(testdir)

	mb, err := NewMessageBus(WithLogPath(testdir))
	require.NoError(err)

	assert.Equal(0, mb.Len())
}

func TestMessage(t *testing.T) {
	assert := assert.New(t)
	require := require.New(t)

	testdir, err := ioutil.TempDir("", "msgbus-logs-*")
	require.NoError(err)
	defer os.RemoveAll(testdir)

	mb, err := NewMessageBus(WithLogPath(testdir))
	require.NoError(err)

	assert.Equal(0, mb.Len())

	topic := mb.NewTopic("foo")
	expected := mb.NewMessage(topic, []byte("bar"))
	err = mb.Put(expected)
	require.NoError(err)

	actual, ok := mb.Get(topic)
	require.True(ok)
	assert.Equal(expected, actual)
}

func TestMessageIds(t *testing.T) {
	assert := assert.New(t)
	require := require.New(t)

	testdir, err := ioutil.TempDir("", "msgbus-logs-*")
	require.NoError(err)
	defer os.RemoveAll(testdir)

	mb, err := NewMessageBus(WithLogPath(testdir))
	require.NoError(err)

	assert.Equal(0, mb.Len())

	topic := mb.NewTopic("foo")
	expected := mb.NewMessage(topic, []byte("bar"))
	mb.Put(expected)

	actual, ok := mb.Get(topic)
	require.True(ok)
	assert.Equal(expected, actual)

	mb.Put(mb.NewMessage(topic, []byte("bar")))
	msg, ok := mb.Get(topic)
	require.True(ok)
	assert.Equal(msg.ID, int64(2))
}

func TestMessageGetEmpty(t *testing.T) {
	assert := assert.New(t)
	require := require.New(t)

	testdir, err := ioutil.TempDir("", "msgbus-logs-*")
	require.NoError(err)
	defer os.RemoveAll(testdir)

	mb, err := NewMessageBus(WithLogPath(testdir))
	require.NoError(err)

	assert.Equal(0, mb.Len())

	topic := mb.NewTopic("foo")
	msg, ok := mb.Get(topic)
	require.False(ok)
	assert.Equal(Message{}, msg)
}

func TestMessageBusPutGet(t *testing.T) {
	assert := assert.New(t)
	require := require.New(t)

	testdir, err := ioutil.TempDir("", "msgbus-logs-*")
	require.NoError(err)
	defer os.RemoveAll(testdir)

	mb, err := NewMessageBus(WithLogPath(testdir))
	require.NoError(err)

	topic := mb.NewTopic("foo")
	expected := mb.NewMessage(topic, []byte("foo"))
	mb.Put(expected)

	actual, ok := mb.Get(topic)
	require.True(ok)
	assert.Equal(expected, actual)
}

func TestMessageBusSubscribe(t *testing.T) {
	assert := assert.New(t)
	require := require.New(t)

	testdir, err := ioutil.TempDir("", "msgbus-logs-*")
	require.NoError(err)
	defer os.RemoveAll(testdir)

	mb, err := NewMessageBus(WithLogPath(testdir))
	require.NoError(err)

	msgs := mb.Subscribe("id1", "foo")

	topic := mb.NewTopic("foo")
	expected := mb.NewMessage(topic, []byte("foo"))
	mb.Put(expected)

	actual := <-msgs
	assert.Equal(expected, actual)
}

func TestMessageBusSubscribeFullBuffer(t *testing.T) {
	require := require.New(t)

	testdir, err := ioutil.TempDir("", "msgbus-logs-*")
	require.NoError(err)
	defer os.RemoveAll(testdir)

	mb, err := NewMessageBus(WithLogPath(testdir), WithBufferLength(2))
	require.NoError(err)

	topic := mb.NewTopic("hello")
	mb.Put(mb.NewMessage(topic, []byte("foo"))) // ID == 1
	mb.Put(mb.NewMessage(topic, []byte("bar"))) // ID == 2
	mb.Put(mb.NewMessage(topic, []byte("baz"))) // ID == 3

	ctx, cancel := context.WithCancel(context.Background())
	defer cancel()

	msgs := mb.Subscribe("id1", "hello")
	go func(ctx context.Context) {
		select {
		case <-msgs:
		case <-ctx.Done():
			return
		}
	}(ctx)

	//err = mb.Put(mb.NewMessage(topic, []byte("baz"))) // ID == 3
	//require.NoError(err)
}

func TestMessageBusSubscribeWithIndex(t *testing.T) {
	assert := assert.New(t)
	require := require.New(t)

	testdir, err := ioutil.TempDir("", "msgbus-logs-*")
	require.NoError(err)
	defer os.RemoveAll(testdir)

	mb, err := NewMessageBus(WithLogPath(testdir))
	require.NoError(err)

	msgs := mb.Subscribe("id1", "foo")

	topic := mb.NewTopic("foo")
	expected := mb.NewMessage(topic, []byte("foo")) // ID == 1
	mb.Put(expected)

	actual := <-msgs
	assert.Equal(expected, actual)
	assert.Equal(int64(1), actual.ID)

	mb.Unsubscribe("id1", "foo")

	require.NoError(mb.Put(mb.NewMessage(topic, []byte("bar")))) // ID == 2
	require.NoError(mb.Put(mb.NewMessage(topic, []byte("baz")))) // ID == 3

	msgs = mb.Subscribe("id1", "foo", WithIndex(1))

	assert.Equal("foo", string((<-msgs).Payload))
	assert.Equal("bar", string((<-msgs).Payload))
	assert.Equal("baz", string((<-msgs).Payload))
}

func TestMessageBusWAL(t *testing.T) {
	assert := assert.New(t)
	require := require.New(t)

	testdir, err := ioutil.TempDir("", "msgbus-logs-*")
	require.NoError(err)
	defer os.RemoveAll(testdir)

	mb, err := NewMessageBus(WithLogPath(testdir))
	require.NoError(err)

	msgs := mb.Subscribe("id1", "hello")

	topic := mb.NewTopic("hello")
	mb.Put(mb.NewMessage(topic, []byte("foo"))) // ID == 1
	mb.Put(mb.NewMessage(topic, []byte("bar"))) // ID == 2
	mb.Put(mb.NewMessage(topic, []byte("baz"))) // ID == 3

	assert.Equal([]byte("foo"), (<-msgs).Payload)
	assert.Equal([]byte("bar"), (<-msgs).Payload)
	assert.Equal([]byte("baz"), (<-msgs).Payload)

	assert.Equal(int64(3), topic.Sequence)

	mb.Unsubscribe("id1", "foo")

	// Now ensure when we start back up we've re-filled the queues and retain the same
	// message ids and topic sequence number

	mb, err = NewMessageBus(WithLogPath(testdir))
	require.NoError(err)

	// we have to tell the bus we want to subscribe from the start
	msgs = mb.Subscribe("id1", "hello", WithIndex(1))

	topic = mb.NewTopic("hello")
	assert.Equal(int64(3), topic.Sequence)

	assert.Equal("foo", string((<-msgs).Payload))
	assert.Equal("bar", string((<-msgs).Payload))
	assert.Equal("baz", string((<-msgs).Payload))

	msg := mb.NewMessage(topic, []byte("foobar"))
	assert.Equal(int64(4), msg.ID)
}

func TestServeHTTPGETIndexEmpty(t *testing.T) {
	assert := assert.New(t)
	require := require.New(t)

	testdir, err := ioutil.TempDir("", "msgbus-logs-*")
	require.NoError(err)
	defer os.RemoveAll(testdir)

	mb, err := NewMessageBus(WithLogPath(testdir))
	require.NoError(err)

	w := httptest.NewRecorder()
	r, _ := http.NewRequest("GET", "/", nil)

	mb.ServeHTTP(w, r)
	assert.Equal(w.Code, http.StatusOK)
	assert.Equal(w.Body.String(), "{}")
}

func TestServeHTTPGETTopics(t *testing.T) {
	assert := assert.New(t)
	require := require.New(t)

	testdir, err := ioutil.TempDir("", "msgbus-logs-*")
	require.NoError(err)
	defer os.RemoveAll(testdir)

	mb, err := NewMessageBus(WithLogPath(testdir))
	require.NoError(err)

	mb.Put(mb.NewMessage(mb.NewTopic("foo"), []byte("foo")))
	mb.Put(mb.NewMessage(mb.NewTopic("hello"), []byte("hello world")))

	w := httptest.NewRecorder()
	r, _ := http.NewRequest("GET", "/", nil)

	mb.ServeHTTP(w, r)
	assert.Equal(w.Code, http.StatusOK)
	assert.Contains(w.Body.String(), "foo")
	assert.Contains(w.Body.String(), "hello")
}

func TestServeHTTPGETEmptyQueue(t *testing.T) {
	assert := assert.New(t)
	require := require.New(t)

	testdir, err := ioutil.TempDir("", "msgbus-logs-*")
	require.NoError(err)
	defer os.RemoveAll(testdir)

	mb, err := NewMessageBus(WithLogPath(testdir))
	require.NoError(err)

	w := httptest.NewRecorder()
	r, _ := http.NewRequest("GET", "/hello", nil)

	mb.ServeHTTP(w, r)
	assert.Equal(w.Code, http.StatusNoContent)
}

func TestServeHTTPPOST(t *testing.T) {
	assert := assert.New(t)
	require := require.New(t)

	testdir, err := ioutil.TempDir("", "msgbus-logs-*")
	require.NoError(err)
	defer os.RemoveAll(testdir)

	mb, err := NewMessageBus(WithLogPath(testdir))
	require.NoError(err)

	w := httptest.NewRecorder()
	b := bytes.NewBufferString("hello world")
	r, _ := http.NewRequest("POST", "/hello", b)

	mb.ServeHTTP(w, r)
	assert.Equal(w.Code, http.StatusAccepted)
}

func TestServeHTTPMaxPayloadSize(t *testing.T) {
	assert := assert.New(t)
	require := require.New(t)

	testdir, err := ioutil.TempDir("", "msgbus-logs-*")
	require.NoError(err)
	defer os.RemoveAll(testdir)

	mb, err := NewMessageBus(WithLogPath(testdir))
	require.NoError(err)

	w := httptest.NewRecorder()
	b := bytes.NewBuffer(bytes.Repeat([]byte{'X'}, (DefaultMaxPayloadSize * 2)))
	r, _ := http.NewRequest("POST", "/hello", b)

	mb.ServeHTTP(w, r)
	assert.Equal(http.StatusRequestEntityTooLarge, w.Code)
	assert.Regexp(`payload exceeds max-payload-size`, w.Body.String())
}

func TestServeHTTPSimple(t *testing.T) {
	assert := assert.New(t)
	require := require.New(t)

	testdir, err := ioutil.TempDir("", "msgbus-logs-*")
	require.NoError(err)
	defer os.RemoveAll(testdir)

	mb, err := NewMessageBus(WithLogPath(testdir))
	require.NoError(err)

	w := httptest.NewRecorder()
	b := bytes.NewBufferString("hello world")
	r, _ := http.NewRequest("POST", "/hello", b)

	mb.ServeHTTP(w, r)
	assert.Equal(w.Code, http.StatusAccepted)

	w = httptest.NewRecorder()
	r, _ = http.NewRequest("GET", "/hello", nil)

	mb.ServeHTTP(w, r)
	assert.Equal(w.Code, http.StatusOK)

	var msg *Message
	json.Unmarshal(w.Body.Bytes(), &msg)
	assert.Equal(int64(1), msg.ID)
	assert.Equal("hello", msg.Topic.Name, "hello")
	assert.Equal([]byte("hello world"), msg.Payload)
}

func BenchmarkServeHTTP_POST(b *testing.B) {
	require := require.New(b)

	b.Run("Sync", func(b *testing.B) {
		testdir, err := ioutil.TempDir("", "msgbus-logs-*")
		require.NoError(err)
		defer os.RemoveAll(testdir)

		mb, err := NewMessageBus(WithLogPath(testdir))
		require.NoError(err)

		b.ResetTimer()
		for i := 0; i < b.N; i++ {
			w := httptest.NewRecorder()
			b := bytes.NewBufferString("hello world")
			r, _ := http.NewRequest("POST", "/hello", b)

			mb.ServeHTTP(w, r)
		}
	})

	b.Run("NoSync", func(b *testing.B) {
		testdir, err := ioutil.TempDir("", "msgbus-logs-*")
		require.NoError(err)
		defer os.RemoveAll(testdir)

		mb, err := NewMessageBus(WithLogPath(testdir), WithNoSync(true))
		require.NoError(err)

		b.ResetTimer()
		for i := 0; i < b.N; i++ {
			w := httptest.NewRecorder()
			b := bytes.NewBufferString("hello world")
			r, _ := http.NewRequest("POST", "/hello", b)

			mb.ServeHTTP(w, r)
		}
	})

}

func TestServeHTTPSubscriber(t *testing.T) {
	assert := assert.New(t)
	require := require.New(t)

	testdir, err := ioutil.TempDir("", "msgbus-logs-*")
	require.NoError(err)
	defer os.RemoveAll(testdir)

	mb, err := NewMessageBus(WithLogPath(testdir))
	require.NoError(err)

	s := httptest.NewServer(mb)
	defer s.Close()

	msgs := make(chan Message, 10)
	ready := make(chan bool, 1)

	consumer := func() {
		var msg Message

		// u := fmt.Sprintf("ws%s/hello", strings.TrimPrefix(s.URL, "http"))
		ws, _, err := websocket.Dial(context.Background(), s.URL+"/hello", nil)
		require.NoError(err)
		defer ws.Close(websocket.StatusNormalClosure, "")

		ready <- true

		err = wsjson.Read(context.Background(), ws, &msg)
		require.NoError(err)

		msgs <- msg
	}

	go consumer()

	<-ready

	c := s.Client()
	b := bytes.NewBufferString("hello world")
	r, err := c.Post(s.URL+"/hello", "text/plain", b)
	require.NoError(err)
	defer r.Body.Close()

	msg := <-msgs
	assert.Equal(int64(1), msg.ID)
	assert.Equal("hello", msg.Topic.Name)
	assert.Equal([]byte("hello world"), msg.Payload)
}

func TestServeHTTPSubscriberReconnect(t *testing.T) {
	assert := assert.New(t)
	require := require.New(t)

	testdir, err := ioutil.TempDir("", "msgbus-logs-*")
	require.NoError(err)
	defer os.RemoveAll(testdir)

	mb, err := NewMessageBus(WithLogPath(testdir))
	require.NoError(err)

	s := httptest.NewServer(mb)

	msgs := make(chan Message, 10)
	ready := make(chan bool, 1)

	consumer := func() {
		var msg Message

		ws, _, err := websocket.Dial(context.Background(), s.URL+"/hello", nil)
		require.NoError(err)
		defer ws.Close(websocket.StatusNormalClosure, "")

		ready <- true

		err = wsjson.Read(context.Background(), ws, &msg)
		require.NoError(err)

		msgs <- msg
	}

	go consumer()

	<-ready

	s.Close()
	s = httptest.NewServer(mb)
	defer s.Close()

	c := s.Client()
	b := bytes.NewBufferString("hello world")
	r, err := c.Post(s.URL+"/hello", "text/plain", b)
	require.NoError(err)
	defer r.Body.Close()

	msg := <-msgs
	assert.Equal(int64(1), msg.ID)
	assert.Equal("hello", msg.Topic.Name)
	assert.Equal([]byte("hello world"), msg.Payload)
}

func TestMsgBusMetrics(t *testing.T) {
	assert := assert.New(t)
	require := require.New(t)

	testdir, err := ioutil.TempDir("", "msgbus-logs-*")
	require.NoError(err)
	defer os.RemoveAll(testdir)

	mb, err := NewMessageBus(WithLogPath(testdir))
	require.NoError(err)

	assert.IsType(&Metrics{}, mb.Metrics())
}

func BenchmarkMessageBusPut(b *testing.B) {
	require := require.New(b)

	b.Run("Sync", func(b *testing.B) {
		testdir, err := ioutil.TempDir("", "msgbus-logs-*")
		require.NoError(err)
		defer os.RemoveAll(testdir)

		mb, err := NewMessageBus(WithLogPath(testdir))
		require.NoError(err)

		topic := mb.NewTopic("foo")
		msg := mb.NewMessage(topic, []byte("foo"))
		b.ResetTimer()
		for i := 0; i < b.N; i++ {
			mb.Put(msg)
		}
	})

	b.Run("NoSync", func(b *testing.B) {
		testdir, err := ioutil.TempDir("", "msgbus-logs-*")
		require.NoError(err)
		defer os.RemoveAll(testdir)

		mb, err := NewMessageBus(WithLogPath(testdir), WithNoSync(true))
		require.NoError(err)

		topic := mb.NewTopic("foo")
		msg := mb.NewMessage(topic, []byte("foo"))
		b.ResetTimer()
		for i := 0; i < b.N; i++ {
			mb.Put(msg)
		}
	})
}

func BenchmarkMessageBusGet(b *testing.B) {
	require := require.New(b)

	testdir, err := ioutil.TempDir("", "msgbus-logs-*")
	require.NoError(err)
	defer os.RemoveAll(testdir)

	mb, err := NewMessageBus(WithLogPath(testdir))
	require.NoError(err)

	topic := mb.NewTopic("foo")
	msg := mb.NewMessage(topic, []byte("foo"))
	for i := 0; i < b.N; i++ {
		mb.Put(msg)
	}
	b.ResetTimer()
	for i := 0; i < b.N; i++ {
		mb.Get(topic)
	}
}

func BenchmarkMessageBusGetEmpty(b *testing.B) {
	require := require.New(b)

	testdir, err := ioutil.TempDir("", "msgbus-logs-*")
	require.NoError(err)
	defer os.RemoveAll(testdir)

	mb, err := NewMessageBus(WithLogPath(testdir))
	require.NoError(err)

	topic := mb.NewTopic("foo")
	b.ResetTimer()
	for i := 0; i < b.N; i++ {
		mb.Get(topic)
	}
}

func BenchmarkMessageBusPutGet(b *testing.B) {
	require := require.New(b)

	b.Run("Sync", func(b *testing.B) {
		testdir, err := ioutil.TempDir("", "msgbus-logs-*")
		require.NoError(err)
		defer os.RemoveAll(testdir)

		mb, err := NewMessageBus(WithLogPath(testdir))
		require.NoError(err)

		topic := mb.NewTopic("foo")
		msg := mb.NewMessage(topic, []byte("foo"))
		b.ResetTimer()
		for i := 0; i < b.N; i++ {
			mb.Put(msg)
			mb.Get(topic)
		}
	})

	b.Run("NoSync", func(b *testing.B) {
		testdir, err := ioutil.TempDir("", "msgbus-logs-*")
		require.NoError(err)
		defer os.RemoveAll(testdir)

		mb, err := NewMessageBus(WithLogPath(testdir), WithNoSync(true))
		require.NoError(err)

		topic := mb.NewTopic("foo")
		msg := mb.NewMessage(topic, []byte("foo"))
		b.ResetTimer()
		for i := 0; i < b.N; i++ {
			mb.Put(msg)
			mb.Get(topic)
		}
	})

}

func TestMain(m *testing.M) {
	flag.Parse()

	if *debug {
		log.SetLevel(log.DebugLevel)
	} else {
		log.SetLevel(log.WarnLevel)
	}

	result := m.Run()

	os.Exit(result)
}