package stream

import (
	"bytes"
	"compress/flate"
	"compress/gzip"
	"context"
	"encoding/json"
	"errors"
	"fmt"
	"net"
	"net/http"
	"os"
	"strconv"
	"strings"
	"sync"
	"testing"
	"time"

	"github.com/gorilla/websocket"
	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"
	"github.com/thrasher-corp/gocryptotrader/common"
	"github.com/thrasher-corp/gocryptotrader/config"
	"github.com/thrasher-corp/gocryptotrader/currency"
	"github.com/thrasher-corp/gocryptotrader/exchanges/protocol"
	"github.com/thrasher-corp/gocryptotrader/exchanges/subscription"
)

const (
	websocketTestURL = "wss://www.bitmex.com/realtime"
	useProxyTests    = false                     // Disabled by default. Freely available proxy servers that work all the time are difficult to find
	proxyURL         = "http://212.186.171.4:80" // Replace with a usable proxy server
)

var (
	errDastardlyReason = errors.New("some dastardly reason")
)

var dialer websocket.Dialer

type testStruct struct {
	Error error
	WC    WebsocketConnection
}

type testRequest struct {
	Event        string          `json:"event"`
	RequestID    int64           `json:"reqid,omitempty"`
	Pairs        []string        `json:"pair"`
	Subscription testRequestData `json:"subscription,omitempty"`
}

// testRequestData contains details on WS channel
type testRequestData struct {
	Name     string `json:"name,omitempty"`
	Interval int64  `json:"interval,omitempty"`
	Depth    int64  `json:"depth,omitempty"`
}

type testResponse struct {
	RequestID int64 `json:"reqid,omitempty"`
}

type testSubKey struct {
	Mood string
}

var defaultSetup = &WebsocketSetup{
	ExchangeConfig: &config.Exchange{
		Features: &config.FeaturesConfig{
			Enabled: config.FeaturesEnabledConfig{Websocket: true},
		},
		API: config.APIConfig{
			AuthenticatedWebsocketSupport: true,
		},
		WebsocketTrafficTimeout: time.Second * 5,
		Name:                    "GTX",
	},
	DefaultURL:   "testDefaultURL",
	RunningURL:   "wss://testRunningURL",
	Connector:    func() error { return nil },
	Subscriber:   func(subscription.List) error { return nil },
	Unsubscriber: func(subscription.List) error { return nil },
	GenerateSubscriptions: func() (subscription.List, error) {
		return subscription.List{
			{Channel: "TestSub"},
			{Channel: "TestSub2", Key: "purple"},
			{Channel: "TestSub3", Key: testSubKey{"mauve"}},
			{Channel: "TestSub4", Key: 42},
		}, nil
	},
	Features: &protocol.Features{Subscribe: true, Unsubscribe: true},
}

type dodgyConnection struct {
	WebsocketConnection
}

// override websocket connection method to produce a wicked terrible error
func (d *dodgyConnection) Shutdown() error {
	return fmt.Errorf("%w: %w", errCannotShutdown, errDastardlyReason)
}

// override websocket connection method to produce a wicked terrible error
func (d *dodgyConnection) Connect() error {
	return fmt.Errorf("cannot connect: %w", errDastardlyReason)
}

func TestMain(m *testing.M) {
	// Change trafficCheckInterval for TestTrafficMonitorTimeout before parallel tests to avoid racing
	trafficCheckInterval = 50 * time.Millisecond
	os.Exit(m.Run())
}

func TestSetup(t *testing.T) {
	t.Parallel()
	var w *Websocket
	err := w.Setup(nil)
	assert.ErrorIs(t, err, errWebsocketIsNil, "Setup should error correctly")

	w = &Websocket{DataHandler: make(chan interface{})}
	err = w.Setup(nil)
	assert.ErrorIs(t, err, errWebsocketSetupIsNil, "Setup should error correctly")

	websocketSetup := &WebsocketSetup{}

	err = w.Setup(websocketSetup)
	assert.ErrorIs(t, err, errExchangeConfigIsNil, "Setup should error correctly")

	websocketSetup.ExchangeConfig = &config.Exchange{}
	err = w.Setup(websocketSetup)
	assert.ErrorIs(t, err, errExchangeConfigNameEmpty, "Setup should error correctly")

	websocketSetup.ExchangeConfig.Name = "testname"
	err = w.Setup(websocketSetup)
	assert.ErrorIs(t, err, errWebsocketFeaturesIsUnset, "Setup should error correctly")

	websocketSetup.Features = &protocol.Features{}
	err = w.Setup(websocketSetup)
	assert.ErrorIs(t, err, errConfigFeaturesIsNil, "Setup should error correctly")

	websocketSetup.ExchangeConfig.Features = &config.FeaturesConfig{}
	err = w.Setup(websocketSetup)
	assert.ErrorIs(t, err, errWebsocketConnectorUnset, "Setup should error correctly")

	websocketSetup.Connector = func() error { return nil }
	err = w.Setup(websocketSetup)
	assert.ErrorIs(t, err, errWebsocketSubscriberUnset, "Setup should error correctly")

	websocketSetup.Subscriber = func(subscription.List) error { return nil }
	websocketSetup.Features.Unsubscribe = true
	err = w.Setup(websocketSetup)
	assert.ErrorIs(t, err, errWebsocketUnsubscriberUnset, "Setup should error correctly")

	websocketSetup.Unsubscriber = func(subscription.List) error { return nil }
	err = w.Setup(websocketSetup)
	assert.ErrorIs(t, err, errWebsocketSubscriptionsGeneratorUnset, "Setup should error correctly")

	websocketSetup.GenerateSubscriptions = func() (subscription.List, error) { return nil, nil }
	err = w.Setup(websocketSetup)
	assert.ErrorIs(t, err, errDefaultURLIsEmpty, "Setup should error correctly")

	websocketSetup.DefaultURL = "test"
	err = w.Setup(websocketSetup)
	assert.ErrorIs(t, err, errRunningURLIsEmpty, "Setup should error correctly")

	websocketSetup.RunningURL = "http://www.google.com"
	err = w.Setup(websocketSetup)
	assert.ErrorIs(t, err, errInvalidWebsocketURL, "Setup should error correctly")

	websocketSetup.RunningURL = "wss://www.google.com"
	websocketSetup.RunningURLAuth = "http://www.google.com"
	err = w.Setup(websocketSetup)
	assert.ErrorIs(t, err, errInvalidWebsocketURL, "Setup should error correctly")

	websocketSetup.RunningURLAuth = "wss://www.google.com"
	err = w.Setup(websocketSetup)
	assert.ErrorIs(t, err, errInvalidTrafficTimeout, "Setup should error correctly")

	websocketSetup.ExchangeConfig.WebsocketTrafficTimeout = time.Minute
	err = w.Setup(websocketSetup)
	assert.NoError(t, err, "Setup should not error")
}

// TestTrafficMonitorTrafficAlerts ensures multiple traffic alerts work and only process one trafficAlert per interval
// ensures shutdown works after traffic alerts
func TestTrafficMonitorTrafficAlerts(t *testing.T) {
	t.Parallel()
	ws := NewWebsocket()
	err := ws.Setup(defaultSetup)
	require.NoError(t, err, "Setup must not error")

	signal := struct{}{}
	patience := 10 * time.Millisecond
	ws.trafficTimeout = 200 * time.Millisecond
	ws.state.Store(connectedState)

	thenish := time.Now()
	ws.trafficMonitor()

	assert.True(t, ws.IsTrafficMonitorRunning(), "traffic monitor should be running")
	require.Equal(t, connectedState, ws.state.Load(), "websocket must be connected")

	for i := range 6 { // Timeout will happen at 200ms so we want 6 * 50ms checks to pass
		select {
		case ws.TrafficAlert <- signal:
			if i == 0 {
				require.WithinDurationf(t, time.Now(), thenish, trafficCheckInterval, "First Non-blocking test must happen before the traffic is checked")
			}
		default:
			require.Failf(t, "", "TrafficAlert should not block; Check #%d", i)
		}

		select {
		case ws.TrafficAlert <- signal:
			require.Failf(t, "", "TrafficAlert should block after first slot used; Check #%d", i)
		default:
			if i == 0 {
				require.WithinDuration(t, time.Now(), thenish, trafficCheckInterval, "First Blocking test must happen before the traffic is checked")
			}
		}

		require.Eventuallyf(t, func() bool { return len(ws.TrafficAlert) == 0 }, 5*time.Second, patience, "trafficAlert should be drained; Check #%d", i)
		assert.Truef(t, ws.IsConnected(), "state should still be connected; Check #%d", i)
	}

	require.EventuallyWithT(t, func(c *assert.CollectT) {
		assert.Equal(c, disconnectedState, ws.state.Load(), "websocket must be disconnected")
		assert.False(c, ws.IsTrafficMonitorRunning(), "trafficMonitor should be shut down")
	}, 2*ws.trafficTimeout, patience, "trafficTimeout should trigger a shutdown once we stop feeding trafficAlerts")
}

// TestTrafficMonitorConnecting ensures connecting status doesn't trigger shutdown
func TestTrafficMonitorConnecting(t *testing.T) {
	t.Parallel()
	ws := NewWebsocket()
	err := ws.Setup(defaultSetup)
	require.NoError(t, err, "Setup must not error")

	ws.state.Store(connectingState)
	ws.trafficTimeout = 50 * time.Millisecond
	ws.trafficMonitor()
	require.True(t, ws.IsTrafficMonitorRunning(), "traffic monitor should be running")
	require.Equal(t, connectingState, ws.state.Load(), "websocket must be connecting")
	<-time.After(4 * ws.trafficTimeout)
	require.Equal(t, connectingState, ws.state.Load(), "websocket must still be connecting after several checks")
	ws.state.Store(connectedState)
	require.EventuallyWithT(t, func(c *assert.CollectT) {
		assert.Equal(c, disconnectedState, ws.state.Load(), "websocket must be disconnected")
		assert.False(c, ws.IsTrafficMonitorRunning(), "trafficMonitor should be shut down")
	}, 4*ws.trafficTimeout, 10*time.Millisecond, "trafficTimeout should trigger a shutdown after connecting status changes")
}

// TestTrafficMonitorShutdown ensures shutdown is processed and waitgroup is cleared
func TestTrafficMonitorShutdown(t *testing.T) {
	t.Parallel()
	ws := NewWebsocket()
	err := ws.Setup(defaultSetup)
	require.NoError(t, err, "Setup must not error")

	ws.state.Store(connectedState)
	ws.trafficTimeout = time.Minute
	ws.trafficMonitor()
	assert.True(t, ws.IsTrafficMonitorRunning(), "traffic monitor should be running")

	wgReady := make(chan bool)
	go func() {
		ws.Wg.Wait()
		close(wgReady)
	}()
	select {
	case <-wgReady:
		require.Failf(t, "", "WaitGroup should be blocking still")
	case <-time.After(trafficCheckInterval):
	}

	close(ws.ShutdownC)

	<-time.After(2 * trafficCheckInterval)
	assert.False(t, ws.IsTrafficMonitorRunning(), "traffic monitor should be shutdown")
	select {
	case <-wgReady:
	default:
		require.Failf(t, "", "WaitGroup should be freed now")
	}
}

func TestIsDisconnectionError(t *testing.T) {
	t.Parallel()
	assert.False(t, IsDisconnectionError(errors.New("errorText")), "IsDisconnectionError should return false")
	assert.True(t, IsDisconnectionError(&websocket.CloseError{Code: 1006, Text: "errorText"}), "IsDisconnectionError should return true")
	assert.False(t, IsDisconnectionError(&net.OpError{Err: errClosedConnection}), "IsDisconnectionError should return false")
	assert.True(t, IsDisconnectionError(&net.OpError{Err: errors.New("errText")}), "IsDisconnectionError should return true")
}

func TestConnectionMessageErrors(t *testing.T) {
	t.Parallel()
	var wsWrong = &Websocket{}
	err := wsWrong.Connect()
	assert.ErrorIs(t, err, errNoConnectFunc, "Connect should error correctly")

	wsWrong.connector = func() error { return nil }
	err = wsWrong.Connect()
	assert.ErrorIs(t, err, ErrWebsocketNotEnabled, "Connect should error correctly")

	wsWrong.setEnabled(true)
	wsWrong.setState(connectingState)
	err = wsWrong.Connect()
	assert.ErrorIs(t, err, errAlreadyReconnecting, "Connect should error correctly")

	wsWrong.setState(disconnectedState)
	err = wsWrong.Connect()
	assert.ErrorIs(t, err, common.ErrNilPointer, "Connect should get a nil pointer error")
	assert.ErrorContains(t, err, "subscriptions", "Connect should get a nil pointer error about subscriptions")

	wsWrong.subscriptions = subscription.NewStore()
	wsWrong.setState(disconnectedState)
	wsWrong.connector = func() error { return errDastardlyReason }
	err = wsWrong.Connect()
	assert.ErrorIs(t, err, errDastardlyReason, "Connect should error correctly")

	ws := NewWebsocket()
	err = ws.Setup(defaultSetup)
	require.NoError(t, err, "Setup must not error")
	ws.trafficTimeout = time.Minute
	ws.connector = connect

	err = ws.Connect()
	require.NoError(t, err, "Connect must not error")

	c := func(tb *assert.CollectT) {
		select {
		case v, ok := <-ws.ToRoutine:
			require.True(tb, ok, "ToRoutine should not be closed on us")
			switch err := v.(type) {
			case *websocket.CloseError:
				assert.Equal(tb, "SpecialText", err.Text, "Should get correct Close Error")
			case error:
				assert.ErrorIs(tb, err, errDastardlyReason, "Should get the correct error")
			default:
				assert.Failf(tb, "Wrong data type sent to ToRoutine", "Got type: %T", err)
			}
		default:
			assert.Fail(tb, "Nothing available on ToRoutine")
		}
	}

	ws.TrafficAlert <- struct{}{}
	ws.ReadMessageErrors <- errDastardlyReason
	assert.EventuallyWithT(t, c, 2*time.Second, 10*time.Millisecond, "Should get an error down the routine")

	ws.ReadMessageErrors <- &websocket.CloseError{Code: 1006, Text: "SpecialText"}
	assert.EventuallyWithT(t, c, 2*time.Second, 10*time.Millisecond, "Should get an error down the routine")
}

func TestWebsocket(t *testing.T) {
	t.Parallel()

	ws := NewWebsocket()

	err := ws.SetProxyAddress("garbagio")
	assert.ErrorContains(t, err, "invalid URI for request", "SetProxyAddress should error correctly")

	ws.Conn = &dodgyConnection{}
	ws.AuthConn = &WebsocketConnection{}
	ws.setEnabled(true)

	err = ws.Setup(defaultSetup) // Sets to enabled again
	require.NoError(t, err, "Setup may not error")

	err = ws.Setup(defaultSetup)
	assert.ErrorIs(t, err, errWebsocketAlreadyInitialised, "Setup should error correctly if called twice")

	assert.Equal(t, "GTX", ws.GetName(), "GetName should return correctly")
	assert.True(t, ws.IsEnabled(), "Websocket should be enabled by Setup")

	ws.setEnabled(false)
	assert.False(t, ws.IsEnabled(), "Websocket should be disabled by setEnabled(false)")

	ws.setEnabled(true)
	assert.True(t, ws.IsEnabled(), "Websocket should be enabled by setEnabled(true)")

	err = ws.SetProxyAddress("https://192.168.0.1:1337")
	assert.NoError(t, err, "SetProxyAddress should not error when not yet connected")

	ws.setState(connectedState)

	err = ws.SetProxyAddress("https://192.168.0.1:1336")
	assert.ErrorIs(t, err, errDastardlyReason, "SetProxyAddress should call Connect and error from there")

	err = ws.SetProxyAddress("https://192.168.0.1:1336")
	assert.ErrorIs(t, err, errSameProxyAddress, "SetProxyAddress should error correctly")

	// removing proxy
	err = ws.SetProxyAddress("")
	assert.ErrorIs(t, err, errDastardlyReason, "SetProxyAddress should call Shutdown and error from there")
	assert.ErrorIs(t, err, errCannotShutdown, "SetProxyAddress should call Shutdown and error from there")

	ws.Conn = &WebsocketConnection{}
	ws.setEnabled(true)

	// reinstate proxy
	err = ws.SetProxyAddress("http://localhost:1337")
	assert.NoError(t, err, "SetProxyAddress should not error")
	assert.Equal(t, "http://localhost:1337", ws.GetProxyAddress(), "GetProxyAddress should return correctly")
	assert.Equal(t, "wss://testRunningURL", ws.GetWebsocketURL(), "GetWebsocketURL should return correctly")
	assert.Equal(t, time.Second*5, ws.trafficTimeout, "trafficTimeout should default correctly")

	ws.setState(connectedState)
	ws.AuthConn = &dodgyConnection{}
	err = ws.Shutdown()
	assert.ErrorIs(t, err, errDastardlyReason, "Shutdown should error correctly with a dodgy authConn")
	assert.ErrorIs(t, err, errCannotShutdown, "Shutdown should error correctly with a dodgy authConn")

	ws.AuthConn = &WebsocketConnection{}
	ws.setState(disconnectedState)

	err = ws.Connect()
	assert.NoError(t, err, "Connect should not error")

	ws.defaultURL = "ws://demos.kaazing.com/echo"
	ws.defaultURLAuth = "ws://demos.kaazing.com/echo"

	err = ws.SetWebsocketURL("", false, false)
	assert.NoError(t, err, "SetWebsocketURL should not error")

	err = ws.SetWebsocketURL("ws://demos.kaazing.com/echo", false, false)
	assert.NoError(t, err, "SetWebsocketURL should not error")

	err = ws.SetWebsocketURL("", true, false)
	assert.NoError(t, err, "SetWebsocketURL should not error")

	err = ws.SetWebsocketURL("ws://demos.kaazing.com/echo", true, false)
	assert.NoError(t, err, "SetWebsocketURL should not error")

	err = ws.SetWebsocketURL("ws://demos.kaazing.com/echo", true, true)
	assert.NoError(t, err, "SetWebsocketURL should not error on reconnect")

	// -- initiate the reconnect which is usually handled by connection monitor
	err = ws.Connect()
	assert.NoError(t, err, "ReConnect called manually should not error")

	err = ws.Connect()
	assert.ErrorIs(t, err, errAlreadyConnected, "ReConnect should error when already connected")

	err = ws.Shutdown()
	assert.NoError(t, err, "Shutdown should not error")
	ws.Wg.Wait()
}

func currySimpleSub(w *Websocket) func(subscription.List) error {
	return func(subs subscription.List) error {
		return w.AddSuccessfulSubscriptions(subs...)
	}
}

func currySimpleUnsub(w *Websocket) func(subscription.List) error {
	return func(unsubs subscription.List) error {
		return w.RemoveSubscriptions(unsubs...)
	}
}

// TestSubscribe logic test
func TestSubscribeUnsubscribe(t *testing.T) {
	t.Parallel()
	ws := NewWebsocket()
	assert.NoError(t, ws.Setup(defaultSetup), "WS Setup should not error")

	ws.Subscriber = currySimpleSub(ws)
	ws.Unsubscriber = currySimpleUnsub(ws)

	subs, err := ws.GenerateSubs()
	require.NoError(t, err, "Generating test subscriptions should not error")
	assert.NoError(t, new(Websocket).UnsubscribeChannels(subs), "Should not error when w.subscriptions is nil")
	assert.NoError(t, ws.UnsubscribeChannels(nil), "Unsubscribing from nil should not error")
	assert.ErrorIs(t, ws.UnsubscribeChannels(subs), subscription.ErrNotFound, "Unsubscribing should error when not subscribed")
	assert.Nil(t, ws.GetSubscription(42), "GetSubscription on empty internal map should return")
	assert.NoError(t, ws.SubscribeToChannels(subs), "Basic Subscribing should not error")
	assert.Len(t, ws.GetSubscriptions(), 4, "Should have 4 subscriptions")
	bySub := ws.GetSubscription(subscription.Subscription{Channel: "TestSub"})
	if assert.NotNil(t, bySub, "GetSubscription by subscription should find a channel") {
		assert.Equal(t, "TestSub", bySub.Channel, "GetSubscription by default key should return a pointer a copy of the right channel")
		assert.Same(t, bySub, subs[0], "GetSubscription returns the same pointer")
	}
	if assert.NotNil(t, ws.GetSubscription("purple"), "GetSubscription by string key should find a channel") {
		assert.Equal(t, "TestSub2", ws.GetSubscription("purple").Channel, "GetSubscription by string key should return a pointer a copy of the right channel")
	}
	if assert.NotNil(t, ws.GetSubscription(testSubKey{"mauve"}), "GetSubscription by type key should find a channel") {
		assert.Equal(t, "TestSub3", ws.GetSubscription(testSubKey{"mauve"}).Channel, "GetSubscription by type key should return a pointer a copy of the right channel")
	}
	if assert.NotNil(t, ws.GetSubscription(42), "GetSubscription by int key should find a channel") {
		assert.Equal(t, "TestSub4", ws.GetSubscription(42).Channel, "GetSubscription by int key should return a pointer a copy of the right channel")
	}
	assert.Nil(t, ws.GetSubscription(nil), "GetSubscription by nil should return nil")
	assert.Nil(t, ws.GetSubscription(45), "GetSubscription by invalid key should return nil")
	assert.ErrorIs(t, ws.SubscribeToChannels(subs), subscription.ErrDuplicate, "Subscribe should error when already subscribed")
	assert.NoError(t, ws.SubscribeToChannels(nil), "Subscribe to an nil List should not error")
	assert.NoError(t, ws.UnsubscribeChannels(subs), "Unsubscribing should not error")

	ws.Subscriber = func(subscription.List) error { return errDastardlyReason }
	assert.ErrorIs(t, ws.SubscribeToChannels(subs), errDastardlyReason, "Should error correctly when error returned from Subscriber")

	err = ws.SubscribeToChannels(subscription.List{nil})
	assert.ErrorIs(t, err, common.ErrNilPointer, "Should error correctly when list contains a nil subscription")
}

// TestResubscribe tests Resubscribing to existing subscriptions
func TestResubscribe(t *testing.T) {
	t.Parallel()
	ws := NewWebsocket()

	wackedOutSetup := *defaultSetup
	wackedOutSetup.MaxWebsocketSubscriptionsPerConnection = -1
	err := ws.Setup(&wackedOutSetup)
	assert.ErrorIs(t, err, errInvalidMaxSubscriptions, "Invalid MaxWebsocketSubscriptionsPerConnection should error")

	err = ws.Setup(defaultSetup)
	assert.NoError(t, err, "WS Setup should not error")

	ws.Subscriber = currySimpleSub(ws)
	ws.Unsubscriber = currySimpleUnsub(ws)

	channel := subscription.List{{Channel: "resubTest"}}

	assert.ErrorIs(t, ws.ResubscribeToChannel(channel[0]), subscription.ErrNotFound, "Resubscribe should error when channel isn't subscribed yet")
	assert.NoError(t, ws.SubscribeToChannels(channel), "Subscribe should not error")
	assert.NoError(t, ws.ResubscribeToChannel(channel[0]), "Resubscribe should not error now the channel is subscribed")
}

// TestSubscriptions tests adding, getting and removing subscriptions
func TestSubscriptions(t *testing.T) {
	t.Parallel()
	w := new(Websocket) // Do not use NewWebsocket; We want to exercise w.subs == nil
	assert.ErrorIs(t, (*Websocket)(nil).AddSubscriptions(nil), common.ErrNilPointer, "Should error correctly when nil websocket")
	s := &subscription.Subscription{Key: 42, Channel: subscription.TickerChannel}
	require.NoError(t, w.AddSubscriptions(s), "Adding first subscription should not error")
	assert.Same(t, s, w.GetSubscription(42), "Get Subscription should retrieve the same subscription")
	assert.ErrorIs(t, w.AddSubscriptions(s), subscription.ErrDuplicate, "Adding same subscription should return error")
	assert.Equal(t, subscription.SubscribingState, s.State(), "Should set state to Subscribing")

	err := w.RemoveSubscriptions(s)
	require.NoError(t, err, "RemoveSubscriptions must not error")
	assert.Nil(t, w.GetSubscription(42), "Remove should have removed the sub")
	assert.Equal(t, subscription.UnsubscribedState, s.State(), "Should set state to Unsubscribed")

	require.NoError(t, s.SetState(subscription.ResubscribingState), "SetState must not error")
	require.NoError(t, w.AddSubscriptions(s), "Adding first subscription should not error")
	assert.Equal(t, subscription.ResubscribingState, s.State(), "Should not change resubscribing state")
}

// TestSuccessfulSubscriptions tests adding, getting and removing subscriptions
func TestSuccessfulSubscriptions(t *testing.T) {
	t.Parallel()
	w := new(Websocket) // Do not use NewWebsocket; We want to exercise w.subs == nil
	assert.ErrorIs(t, (*Websocket)(nil).AddSuccessfulSubscriptions(nil), common.ErrNilPointer, "Should error correctly when nil websocket")
	c := &subscription.Subscription{Key: 42, Channel: subscription.TickerChannel}
	require.NoError(t, w.AddSuccessfulSubscriptions(c), "Adding first subscription should not error")
	assert.Same(t, c, w.GetSubscription(42), "Get Subscription should retrieve the same subscription")
	assert.ErrorIs(t, w.AddSuccessfulSubscriptions(c), subscription.ErrInStateAlready, "Adding subscription in same state should return error")
	require.NoError(t, c.SetState(subscription.SubscribingState), "SetState must not error")
	assert.ErrorIs(t, w.AddSuccessfulSubscriptions(c), subscription.ErrDuplicate, "Adding same subscription should return error")

	err := w.RemoveSubscriptions(c)
	require.NoError(t, err, "RemoveSubscriptions must not error")
	assert.Nil(t, w.GetSubscription(42), "Remove should have removed the sub")
	assert.ErrorIs(t, w.RemoveSubscriptions(c), subscription.ErrNotFound, "Should error correctly when not found")
	assert.ErrorIs(t, (*Websocket)(nil).RemoveSubscriptions(nil), common.ErrNilPointer, "Should error correctly when nil websocket")
	w.subscriptions = nil
	assert.ErrorIs(t, w.RemoveSubscriptions(c), common.ErrNilPointer, "Should error correctly when nil websocket")
}

// TestConnectionMonitorNoConnection logic test
func TestConnectionMonitorNoConnection(t *testing.T) {
	t.Parallel()
	ws := NewWebsocket()
	ws.connectionMonitorDelay = 500
	ws.exchangeName = "hello"
	ws.setEnabled(true)
	err := ws.connectionMonitor()
	require.NoError(t, err, "connectionMonitor must not error")
	assert.True(t, ws.IsConnectionMonitorRunning(), "IsConnectionMonitorRunning should return true")
	err = ws.connectionMonitor()
	assert.ErrorIs(t, err, errAlreadyRunning, "connectionMonitor should error correctly")
}

// TestGetSubscription logic test
func TestGetSubscription(t *testing.T) {
	t.Parallel()
	assert.Nil(t, (*Websocket).GetSubscription(nil, "imaginary"), "GetSubscription on a nil Websocket should return nil")
	assert.Nil(t, (&Websocket{}).GetSubscription("empty"), "GetSubscription on a Websocket with no sub store should return nil")
	w := NewWebsocket()
	assert.Nil(t, w.GetSubscription(nil), "GetSubscription with a nil key should return nil")
	s := &subscription.Subscription{Key: 42, Channel: "hello3"}
	require.NoError(t, w.AddSubscriptions(s), "AddSubscriptions must not error")
	assert.Same(t, s, w.GetSubscription(42), "GetSubscription should delegate to the store")
}

// TestGetSubscriptions logic test
func TestGetSubscriptions(t *testing.T) {
	t.Parallel()
	assert.Nil(t, (*Websocket).GetSubscriptions(nil), "GetSubscription on a nil Websocket should return nil")
	assert.Nil(t, (&Websocket{}).GetSubscriptions(), "GetSubscription on a Websocket with no sub store should return nil")
	w := NewWebsocket()
	s := subscription.List{
		{Key: 42, Channel: "hello3"},
		{Key: 45, Channel: "hello4"},
	}
	err := w.AddSubscriptions(s...)
	require.NoError(t, err, "AddSubscriptions must not error")
	assert.ElementsMatch(t, s, w.GetSubscriptions(), "GetSubscriptions should return the correct channel details")
}

// TestSetCanUseAuthenticatedEndpoints logic test
func TestSetCanUseAuthenticatedEndpoints(t *testing.T) {
	t.Parallel()
	ws := NewWebsocket()
	assert.False(t, ws.CanUseAuthenticatedEndpoints(), "CanUseAuthenticatedEndpoints should return false")
	ws.SetCanUseAuthenticatedEndpoints(true)
	assert.True(t, ws.CanUseAuthenticatedEndpoints(), "CanUseAuthenticatedEndpoints should return true")
}

// TestDial logic test
func TestDial(t *testing.T) {
	t.Parallel()
	var testCases = []testStruct{
		{Error: nil,
			WC: WebsocketConnection{
				ExchangeName:     "test1",
				Verbose:          true,
				URL:              websocketTestURL,
				RateLimit:        10,
				ResponseMaxLimit: 7000000000,
			},
		},
		{Error: errors.New(" Error: malformed ws or wss URL"),
			WC: WebsocketConnection{
				ExchangeName:     "test2",
				Verbose:          true,
				URL:              "",
				ResponseMaxLimit: 7000000000,
			},
		},
		{Error: nil,
			WC: WebsocketConnection{
				ExchangeName:     "test3",
				Verbose:          true,
				URL:              websocketTestURL,
				ProxyURL:         proxyURL,
				ResponseMaxLimit: 7000000000,
			},
		},
	}
	for i := range testCases {
		testData := &testCases[i]
		t.Run(testData.WC.ExchangeName, func(t *testing.T) {
			t.Parallel()
			if testData.WC.ProxyURL != "" && !useProxyTests {
				t.Skip("Proxy testing not enabled, skipping")
			}
			err := testData.WC.Dial(&dialer, http.Header{})
			if err != nil {
				if testData.Error != nil && strings.Contains(err.Error(), testData.Error.Error()) {
					return
				}
				t.Fatal(err)
			}
		})
	}
}

// TestSendMessage logic test
func TestSendMessage(t *testing.T) {
	t.Parallel()
	var testCases = []testStruct{
		{Error: nil, WC: WebsocketConnection{
			ExchangeName:     "test1",
			Verbose:          true,
			URL:              websocketTestURL,
			RateLimit:        10,
			ResponseMaxLimit: 7000000000,
		},
		},
		{Error: errors.New(" Error: malformed ws or wss URL"),
			WC: WebsocketConnection{
				ExchangeName:     "test2",
				Verbose:          true,
				URL:              "",
				ResponseMaxLimit: 7000000000,
			},
		},
		{Error: nil,
			WC: WebsocketConnection{
				ExchangeName:     "test3",
				Verbose:          true,
				URL:              websocketTestURL,
				ProxyURL:         proxyURL,
				ResponseMaxLimit: 7000000000,
			},
		},
	}
	for i := range testCases {
		testData := &testCases[i]
		t.Run(testData.WC.ExchangeName, func(t *testing.T) {
			t.Parallel()
			if testData.WC.ProxyURL != "" && !useProxyTests {
				t.Skip("Proxy testing not enabled, skipping")
			}
			err := testData.WC.Dial(&dialer, http.Header{})
			if err != nil {
				if testData.Error != nil && strings.Contains(err.Error(), testData.Error.Error()) {
					return
				}
				t.Fatal(err)
			}
			err = testData.WC.SendJSONMessage(Ping)
			if err != nil {
				t.Error(err)
			}
			err = testData.WC.SendRawMessage(websocket.TextMessage, []byte(Ping))
			if err != nil {
				t.Error(err)
			}
		})
	}
}

func TestSendMessageReturnResponse(t *testing.T) {
	t.Parallel()
	wc := &WebsocketConnection{
		Verbose:          true,
		URL:              "wss://ws.kraken.com",
		ResponseMaxLimit: time.Second * 5,
		Match:            NewMatch(),
	}
	if wc.ProxyURL != "" && !useProxyTests {
		t.Skip("Proxy testing not enabled, skipping")
	}

	err := wc.Dial(&dialer, http.Header{})
	if err != nil {
		t.Fatal(err)
	}

	go readMessages(t, wc)

	request := testRequest{
		Event: "subscribe",
		Pairs: []string{currency.NewPairWithDelimiter("XBT", "USD", "/").String()},
		Subscription: testRequestData{
			Name: "ticker",
		},
		RequestID: wc.GenerateMessageID(false),
	}

	_, err = wc.SendMessageReturnResponse(context.Background(), request.RequestID, request)
	if err != nil {
		t.Error(err)
	}

	cancelledCtx, fn := context.WithDeadline(context.Background(), time.Now())
	fn()
	_, err = wc.SendMessageReturnResponse(cancelledCtx, "123", request)
	assert.ErrorIs(t, err, context.DeadlineExceeded)

	// with timeout
	wc.ResponseMaxLimit = 1
	_, err = wc.SendMessageReturnResponse(context.Background(), "123", request)
	assert.ErrorIs(t, err, ErrSignatureTimeout, "SendMessageReturnResponse should error when request ID not found")
}

type reporter struct {
	name string
	msg  []byte
	t    time.Duration
}

func (r *reporter) Latency(name string, message []byte, t time.Duration) {
	r.name = name
	r.msg = message
	r.t = t
}

// readMessages helper func
func readMessages(t *testing.T, wc *WebsocketConnection) {
	t.Helper()
	timer := time.NewTimer(20 * time.Second)
	for {
		select {
		case <-timer.C:
			return
		default:
			resp := wc.ReadMessage()
			if resp.Raw == nil {
				t.Error("connection has closed")
				return
			}
			var incoming testResponse
			err := json.Unmarshal(resp.Raw, &incoming)
			if err != nil {
				t.Error(err)
				return
			}
			if incoming.RequestID > 0 {
				wc.Match.IncomingWithData(incoming.RequestID, resp.Raw)
				return
			}
		}
	}
}

// TestSetupPingHandler logic test
func TestSetupPingHandler(t *testing.T) {
	t.Parallel()
	wc := &WebsocketConnection{
		URL:              websocketTestURL,
		ResponseMaxLimit: time.Second * 5,
		Match:            NewMatch(),
		Wg:               &sync.WaitGroup{},
	}

	if wc.ProxyURL != "" && !useProxyTests {
		t.Skip("Proxy testing not enabled, skipping")
	}
	wc.ShutdownC = make(chan struct{})
	err := wc.Dial(&dialer, http.Header{})
	if err != nil {
		t.Fatal(err)
	}

	wc.SetupPingHandler(PingHandler{
		UseGorillaHandler: true,
		MessageType:       websocket.PingMessage,
		Delay:             100,
	})

	err = wc.Connection.Close()
	if err != nil {
		t.Error(err)
	}

	err = wc.Dial(&dialer, http.Header{})
	if err != nil {
		t.Fatal(err)
	}
	wc.SetupPingHandler(PingHandler{
		MessageType: websocket.TextMessage,
		Message:     []byte(Ping),
		Delay:       200,
	})
	time.Sleep(time.Millisecond * 201)
	close(wc.ShutdownC)
	wc.Wg.Wait()
}

// TestParseBinaryResponse logic test
func TestParseBinaryResponse(t *testing.T) {
	t.Parallel()
	wc := &WebsocketConnection{
		URL:              websocketTestURL,
		ResponseMaxLimit: time.Second * 5,
		Match:            NewMatch(),
	}

	var b bytes.Buffer
	g := gzip.NewWriter(&b)
	_, err := g.Write([]byte("hello"))
	require.NoError(t, err, "gzip.Write must not error")
	assert.NoError(t, g.Close(), "Close should not error")

	resp, err := wc.parseBinaryResponse(b.Bytes())
	assert.NoError(t, err, "parseBinaryResponse should not error parsing gzip")
	assert.EqualValues(t, "hello", resp, "parseBinaryResponse should decode gzip")

	b.Reset()
	f, err := flate.NewWriter(&b, 1)
	require.NoError(t, err, "flate.NewWriter must not error")
	_, err = f.Write([]byte("goodbye"))
	require.NoError(t, err, "flate.Write must not error")
	assert.NoError(t, f.Close(), "Close should not error")

	resp, err = wc.parseBinaryResponse(b.Bytes())
	assert.NoError(t, err, "parseBinaryResponse should not error parsing inflate")
	assert.EqualValues(t, "goodbye", resp, "parseBinaryResponse should deflate")

	_, err = wc.parseBinaryResponse([]byte{})
	assert.ErrorContains(t, err, "unexpected EOF", "parseBinaryResponse should error on empty input")
}

// TestCanUseAuthenticatedWebsocketForWrapper logic test
func TestCanUseAuthenticatedWebsocketForWrapper(t *testing.T) {
	t.Parallel()
	ws := &Websocket{}
	assert.False(t, ws.CanUseAuthenticatedWebsocketForWrapper(), "CanUseAuthenticatedWebsocketForWrapper should return false")

	ws.setState(connectedState)
	require.True(t, ws.IsConnected(), "IsConnected must return true")
	assert.False(t, ws.CanUseAuthenticatedWebsocketForWrapper(), "CanUseAuthenticatedWebsocketForWrapper should return false")

	ws.SetCanUseAuthenticatedEndpoints(true)
	assert.True(t, ws.CanUseAuthenticatedWebsocketForWrapper(), "CanUseAuthenticatedWebsocketForWrapper should return true")
}

func TestGenerateMessageID(t *testing.T) {
	t.Parallel()
	wc := WebsocketConnection{}
	const spins = 1000
	ids := make([]int64, spins)
	for i := range spins {
		id := wc.GenerateMessageID(true)
		assert.NotContains(t, ids, id, "GenerateMessageID must not generate the same ID twice")
		ids[i] = id
	}
}

// BenchmarkGenerateMessageID-8   	 2850018	       408 ns/op	      56 B/op	       4 allocs/op
func BenchmarkGenerateMessageID_High(b *testing.B) {
	wc := WebsocketConnection{}
	for i := 0; i < b.N; i++ {
		_ = wc.GenerateMessageID(true)
	}
}

// BenchmarkGenerateMessageID_Low-8   	 2591596	       447 ns/op	      56 B/op	       4 allocs/op
func BenchmarkGenerateMessageID_Low(b *testing.B) {
	wc := WebsocketConnection{}
	for i := 0; i < b.N; i++ {
		_ = wc.GenerateMessageID(false)
	}
}

func TestCheckWebsocketURL(t *testing.T) {
	err := checkWebsocketURL("")
	assert.ErrorIs(t, err, errInvalidWebsocketURL, "checkWebsocketURL should error correctly on empty string")

	err = checkWebsocketURL("wowowow:wowowowo")
	assert.ErrorIs(t, err, errInvalidWebsocketURL, "checkWebsocketURL should error correctly on bad format")

	err = checkWebsocketURL("://")
	assert.ErrorContains(t, err, "missing protocol scheme", "checkWebsocketURL should error correctly on bad proto")

	err = checkWebsocketURL("http://www.google.com")
	assert.ErrorIs(t, err, errInvalidWebsocketURL, "checkWebsocketURL should error correctly on wrong proto")

	err = checkWebsocketURL("wss://websocketconnection.place")
	assert.NoError(t, err, "checkWebsocketURL should not error")

	err = checkWebsocketURL("ws://websocketconnection.place")
	assert.NoError(t, err, "checkWebsocketURL should not error")
}

// TestGetChannelDifference exercises GetChannelDifference
// See subscription.TestStoreDiff for further testing
func TestGetChannelDifference(t *testing.T) {
	t.Parallel()

	w := &Websocket{}
	assert.NotPanics(t, func() { w.GetChannelDifference(subscription.List{}) }, "Should not panic when called without a store")
	subs, unsubs := w.GetChannelDifference(subscription.List{{Channel: subscription.CandlesChannel}})
	require.Equal(t, 1, len(subs), "Should get the correct number of subs")
	require.Empty(t, unsubs, "Should get no unsubs")
	require.NoError(t, w.AddSubscriptions(subs...), "AddSubscriptions must not error")
	subs, unsubs = w.GetChannelDifference(subscription.List{{Channel: subscription.TickerChannel}})
	require.Equal(t, 1, len(subs), "Should get the correct number of subs")
	assert.Equal(t, 1, len(unsubs), "Should get the correct number of unsubs")
}

// GenSubs defines a theoretical exchange with pair management
type GenSubs struct {
	EnabledPairs currency.Pairs
	subscribos   subscription.List
	unsubscribos subscription.List
}

// generateSubs default subs created from the enabled pairs list
func (g *GenSubs) generateSubs() (subscription.List, error) {
	superduperchannelsubs := make(subscription.List, len(g.EnabledPairs))
	for i := range g.EnabledPairs {
		superduperchannelsubs[i] = &subscription.Subscription{
			Channel: "TEST:" + strconv.FormatInt(int64(i), 10),
			Pairs:   currency.Pairs{g.EnabledPairs[i]},
		}
	}
	return superduperchannelsubs, nil
}

func (g *GenSubs) SUBME(subs subscription.List) error {
	if len(subs) == 0 {
		return errors.New("WOW")
	}
	g.subscribos = subs
	return nil
}

func (g *GenSubs) UNSUBME(unsubs subscription.List) error {
	if len(unsubs) == 0 {
		return errors.New("WOW")
	}
	g.unsubscribos = unsubs
	return nil
}

// sneaky connect func
func connect() error { return nil }

func TestFlushChannels(t *testing.T) {
	t.Parallel()
	// Enabled pairs/setup system
	newgen := GenSubs{EnabledPairs: []currency.Pair{
		currency.NewPair(currency.BTC, currency.AUD),
		currency.NewPair(currency.BTC, currency.USDT),
	}}

	dodgyWs := Websocket{}
	err := dodgyWs.FlushChannels()
	assert.ErrorIs(t, err, ErrWebsocketNotEnabled, "FlushChannels should error correctly")

	dodgyWs.setEnabled(true)
	err = dodgyWs.FlushChannels()
	assert.ErrorIs(t, err, ErrNotConnected, "FlushChannels should error correctly")

	w := NewWebsocket()
	w.connector = connect
	w.Subscriber = newgen.SUBME
	w.Unsubscriber = newgen.UNSUBME
	// Added for when we utilise connect() in FlushChannels() so the traffic monitor doesn't time out and turn this to an unconnected state
	w.trafficTimeout = time.Second * 30

	w.setEnabled(true)
	w.setState(connectedState)

	problemFunc := func() (subscription.List, error) {
		return nil, errDastardlyReason
	}

	noSub := func() (subscription.List, error) {
		return nil, nil
	}

	// Disable pair and flush system
	newgen.EnabledPairs = []currency.Pair{
		currency.NewPair(currency.BTC, currency.AUD)}
	w.GenerateSubs = func() (subscription.List, error) {
		return subscription.List{{Channel: "test"}}, nil
	}
	err = w.FlushChannels()
	require.NoError(t, err, "Flush Channels must not error")

	w.features.FullPayloadSubscribe = true
	w.GenerateSubs = problemFunc
	err = w.FlushChannels() // error on full subscribeToChannels
	assert.ErrorIs(t, err, errDastardlyReason, "FlushChannels should error correctly on GenerateSubs")

	w.GenerateSubs = noSub
	err = w.FlushChannels() // No subs to sub
	assert.NoError(t, err, "Flush Channels should not error")

	w.GenerateSubs = newgen.generateSubs
	subs, err := w.GenerateSubs()
	require.NoError(t, err, "GenerateSubs must not error")
	require.NoError(t, w.AddSubscriptions(subs...), "AddSubscriptions must not error")
	err = w.FlushChannels()
	assert.NoError(t, err, "FlushChannels should not error")
	w.features.FullPayloadSubscribe = false
	w.features.Subscribe = true

	w.GenerateSubs = newgen.generateSubs
	w.subscriptions = subscription.NewStore()
	err = w.subscriptions.Add(&subscription.Subscription{
		Key:     41,
		Channel: "match channel",
		Pairs:   currency.Pairs{currency.NewPair(currency.BTC, currency.AUD)},
	})
	require.NoError(t, err, "AddSubscription must not error")
	err = w.subscriptions.Add(&subscription.Subscription{
		Key:     42,
		Channel: "unsub channel",
		Pairs:   currency.Pairs{currency.NewPair(currency.THETA, currency.USDT)},
	})
	require.NoError(t, err, "AddSubscription must not error")

	err = w.FlushChannels()
	assert.NoError(t, err, "FlushChannels should not error")

	w.setState(connectedState)
	w.features.Unsubscribe = true
	err = w.FlushChannels()
	assert.NoError(t, err, "FlushChannels should not error")
}

func TestDisable(t *testing.T) {
	t.Parallel()
	w := NewWebsocket()
	w.setEnabled(true)
	w.setState(connectedState)
	require.NoError(t, w.Disable(), "Disable must not error")
	assert.ErrorIs(t, w.Disable(), ErrAlreadyDisabled, "Disable should error correctly")
}

func TestEnable(t *testing.T) {
	t.Parallel()
	w := NewWebsocket()
	w.connector = connect
	w.Subscriber = func(subscription.List) error { return nil }
	w.Unsubscriber = func(subscription.List) error { return nil }
	w.GenerateSubs = func() (subscription.List, error) { return nil, nil }
	require.NoError(t, w.Enable(), "Enable must not error")
	assert.ErrorIs(t, w.Enable(), errWebsocketAlreadyEnabled, "Enable should error correctly")
}

func TestSetupNewConnection(t *testing.T) {
	t.Parallel()
	var nonsenseWebsock *Websocket
	err := nonsenseWebsock.SetupNewConnection(ConnectionSetup{URL: "urlstring"})
	assert.ErrorIs(t, err, errWebsocketIsNil, "SetupNewConnection should error correctly")

	nonsenseWebsock = &Websocket{}
	err = nonsenseWebsock.SetupNewConnection(ConnectionSetup{URL: "urlstring"})
	assert.ErrorIs(t, err, errExchangeConfigNameEmpty, "SetupNewConnection should error correctly")

	nonsenseWebsock = &Websocket{exchangeName: "test"}
	err = nonsenseWebsock.SetupNewConnection(ConnectionSetup{URL: "urlstring"})
	assert.ErrorIs(t, err, errTrafficAlertNil, "SetupNewConnection should error correctly")

	nonsenseWebsock.TrafficAlert = make(chan struct{}, 1)
	err = nonsenseWebsock.SetupNewConnection(ConnectionSetup{URL: "urlstring"})
	assert.ErrorIs(t, err, errReadMessageErrorsNil, "SetupNewConnection should error correctly")

	web := NewWebsocket()

	err = web.Setup(defaultSetup)
	assert.NoError(t, err, "Setup should not error")

	err = web.SetupNewConnection(ConnectionSetup{})
	assert.ErrorIs(t, err, errExchangeConfigEmpty, "SetupNewConnection should error correctly")

	err = web.SetupNewConnection(ConnectionSetup{URL: "urlstring"})
	assert.NoError(t, err, "SetupNewConnection should not error")

	err = web.SetupNewConnection(ConnectionSetup{URL: "urlstring", Authenticated: true})
	assert.NoError(t, err, "SetupNewConnection should not error")
}

func TestWebsocketConnectionShutdown(t *testing.T) {
	t.Parallel()
	wc := WebsocketConnection{}
	err := wc.Shutdown()
	assert.NoError(t, err, "Shutdown should not error")

	err = wc.Dial(&websocket.Dialer{}, nil)
	assert.ErrorContains(t, err, "malformed ws or wss URL", "Dial must error correctly")

	wc.URL = websocketTestURL

	err = wc.Dial(&websocket.Dialer{}, nil)
	require.NoError(t, err, "Dial must not error")

	err = wc.Shutdown()
	require.NoError(t, err, "Shutdown must not error")
}

// TestLatency logic test
func TestLatency(t *testing.T) {
	t.Parallel()
	r := &reporter{}
	exch := "Kraken"
	wc := &WebsocketConnection{
		ExchangeName:     exch,
		Verbose:          true,
		URL:              "wss://ws.kraken.com",
		ResponseMaxLimit: time.Second * 5,
		Match:            NewMatch(),
		Reporter:         r,
	}
	if wc.ProxyURL != "" && !useProxyTests {
		t.Skip("Proxy testing not enabled, skipping")
	}

	err := wc.Dial(&dialer, http.Header{})
	if err != nil {
		t.Fatal(err)
	}

	go readMessages(t, wc)

	request := testRequest{
		Event: "subscribe",
		Pairs: []string{currency.NewPairWithDelimiter("XBT", "USD", "/").String()},
		Subscription: testRequestData{
			Name: "ticker",
		},
		RequestID: wc.GenerateMessageID(false),
	}

	_, err = wc.SendMessageReturnResponse(context.Background(), request.RequestID, request)
	if err != nil {
		t.Error(err)
	}

	if r.t == 0 {
		t.Error("expected a nonzero duration, got zero")
	}

	if r.name != exch {
		t.Errorf("expected %v, got %v", exch, r.name)
	}
}

func TestCheckSubscriptions(t *testing.T) {
	t.Parallel()
	ws := Websocket{}
	err := ws.checkSubscriptions(nil)
	assert.ErrorIs(t, err, common.ErrNilPointer, "checkSubscriptions should error correctly on nil w.subscriptions")
	assert.ErrorContains(t, err, "Websocket.subscriptions", "checkSubscriptions should error giving context correctly on nil w.subscriptions")

	ws.subscriptions = subscription.NewStore()
	err = ws.checkSubscriptions(nil)
	assert.NoError(t, err, "checkSubscriptions should not error on a nil list")

	ws.MaxSubscriptionsPerConnection = 1

	err = ws.checkSubscriptions(subscription.List{{}})
	assert.NoError(t, err, "checkSubscriptions should not error when subscriptions is empty")

	ws.subscriptions = subscription.NewStore()
	err = ws.checkSubscriptions(subscription.List{{}, {}})
	assert.ErrorIs(t, err, errSubscriptionsExceedsLimit, "checkSubscriptions should error correctly")

	ws.MaxSubscriptionsPerConnection = 2

	ws.subscriptions = subscription.NewStore()
	err = ws.subscriptions.Add(&subscription.Subscription{Key: 42, Channel: "test"})
	require.NoError(t, err, "Add subscription must not error")
	err = ws.checkSubscriptions(subscription.List{{Key: 42, Channel: "test"}})
	assert.ErrorIs(t, err, subscription.ErrDuplicate, "checkSubscriptions should error correctly")

	err = ws.checkSubscriptions(subscription.List{{}})
	assert.NoError(t, err, "checkSubscriptions should not error")
}