package stream

import (
	"bytes"
	"compress/flate"
	"compress/gzip"
	"context"
	"encoding/json"
	"errors"
	"net/http"
	"net/http/httptest"
	"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/request"
	"github.com/thrasher-corp/gocryptotrader/exchanges/subscription"
	mockws "github.com/thrasher-corp/gocryptotrader/internal/testing/websocket"
)

const (
	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")
)

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},
}

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

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

	websocketSetup := &WebsocketSetup{}

	err = w.Setup(websocketSetup)
	assert.ErrorIs(t, err, errExchangeConfigIsNil)

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

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

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

	websocketSetup.ExchangeConfig.Features = &config.FeaturesConfig{}
	websocketSetup.Subscriber = func(subscription.List) error { return nil } // kicks off the setup
	err = w.Setup(websocketSetup)
	assert.ErrorIs(t, err, errWebsocketConnectorUnset)
	websocketSetup.Subscriber = nil

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

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

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

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

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

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

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

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

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

func TestConnectionMessageErrors(t *testing.T) {
	t.Parallel()
	var wsWrong = &Websocket{}
	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")

	checkToRoutineResult := func(t *testing.T) {
		t.Helper()
		v, ok := <-ws.ToRoutine
		require.True(t, ok, "ToRoutine should not be closed on us")
		switch err := v.(type) {
		case *websocket.CloseError:
			assert.Equal(t, "SpecialText", err.Text, "Should get correct Close Error")
		case error:
			assert.ErrorIs(t, err, errDastardlyReason, "Should get the correct error")
		default:
			assert.Failf(t, "Wrong data type sent to ToRoutine", "Got type: %T", err)
		}
	}

	ws.TrafficAlert <- struct{}{}
	ws.ReadMessageErrors <- errDastardlyReason
	checkToRoutineResult(t)

	ws.ReadMessageErrors <- &websocket.CloseError{Code: 1006, Text: "SpecialText"}
	checkToRoutineResult(t)

	// Test individual connection defined functions
	require.NoError(t, ws.Shutdown())
	ws.useMultiConnectionManagement = true

	err = ws.Connect()
	assert.ErrorIs(t, err, errNoPendingConnections, "Connect should error correctly")

	ws.useMultiConnectionManagement = true

	mock := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) { mockws.WsMockUpgrader(t, w, r, mockws.EchoHandler) }))
	defer mock.Close()
	ws.connectionManager = []ConnectionWrapper{{Setup: &ConnectionSetup{URL: "ws" + mock.URL[len("http"):] + "/ws"}}}
	err = ws.Connect()
	require.ErrorIs(t, err, errWebsocketSubscriptionsGeneratorUnset)

	ws.connectionManager[0].Setup.GenerateSubscriptions = func() (subscription.List, error) {
		return nil, errDastardlyReason
	}
	err = ws.Connect()
	require.ErrorIs(t, err, errDastardlyReason)

	ws.connectionManager[0].Setup.GenerateSubscriptions = func() (subscription.List, error) {
		return subscription.List{{}}, nil
	}
	err = ws.Connect()
	require.ErrorIs(t, err, errNoConnectFunc)

	ws.connectionManager[0].Setup.Connector = func(context.Context, Connection) error {
		return errDastardlyReason
	}
	err = ws.Connect()
	require.ErrorIs(t, err, errWebsocketDataHandlerUnset)

	ws.connectionManager[0].Setup.Handler = func(context.Context, []byte) error {
		return errDastardlyReason
	}
	err = ws.Connect()
	require.ErrorIs(t, err, errWebsocketSubscriberUnset)

	ws.connectionManager[0].Setup.Subscriber = func(context.Context, Connection, subscription.List) error {
		return errDastardlyReason
	}
	err = ws.Connect()
	require.ErrorIs(t, err, errDastardlyReason)

	ws.connectionManager[0].Setup.Connector = func(ctx context.Context, conn Connection) error {
		return conn.DialContext(ctx, websocket.DefaultDialer, nil)
	}
	err = ws.Connect()
	require.ErrorIs(t, err, errDastardlyReason)

	ws.connectionManager[0].Setup.Handler = func(context.Context, []byte) error {
		return errDastardlyReason
	}
	err = ws.Connect()
	require.ErrorIs(t, err, errDastardlyReason)

	ws.connectionManager[0].Setup.Subscriber = func(context.Context, Connection, subscription.List) error {
		return nil
	}
	err = ws.Connect()
	require.NoError(t, err)

	err = ws.connectionManager[0].Connection.SendRawMessage(context.Background(), request.Unset, websocket.TextMessage, []byte("test"))
	require.NoError(t, err)

	require.NoError(t, err)
	require.NoError(t, ws.Shutdown())
}

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.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)

	ws.connector = func() error { return errDastardlyReason }
	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
	assert.NoError(t, ws.SetProxyAddress(""))

	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")

	assert.ErrorIs(t, ws.Shutdown(), ErrNotConnected)
	ws.setState(connectedState)
	assert.NoError(t, ws.Shutdown())

	ws.connector = func() error { return nil }
	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()

	ws.useMultiConnectionManagement = true

	ws.connectionManager = []ConnectionWrapper{{Setup: &ConnectionSetup{URL: "ws://demos.kaazing.com/echo"}, Connection: &WebsocketConnection{}}}
	err = ws.SetProxyAddress("https://192.168.0.1:1337")
	require.NoError(t, err)
}

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

func currySimpleSubConn(w *Websocket) func(context.Context, Connection, subscription.List) error {
	return func(_ context.Context, conn Connection, subs subscription.List) error {
		return w.AddSuccessfulSubscriptions(conn, subs...)
	}
}

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

func currySimpleUnsubConn(w *Websocket) func(context.Context, Connection, subscription.List) error {
	return func(_ context.Context, conn Connection, unsubs subscription.List) error {
		return w.RemoveSubscriptions(conn, 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(nil, subs), "Should not error when w.subscriptions is nil")
	assert.NoError(t, ws.UnsubscribeChannels(nil, nil), "Unsubscribing from nil should not error")
	assert.ErrorIs(t, ws.UnsubscribeChannels(nil, 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(nil, 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(nil, subs), subscription.ErrDuplicate, "Subscribe should error when already subscribed")
	assert.NoError(t, ws.SubscribeToChannels(nil, nil), "Subscribe to an nil List should not error")
	assert.NoError(t, ws.UnsubscribeChannels(nil, subs), "Unsubscribing should not error")

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

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

	multi := NewWebsocket()
	set := *defaultSetup
	set.UseMultiConnectionManagement = true
	assert.NoError(t, multi.Setup(&set))

	amazingCandidate := &ConnectionSetup{
		URL:                   "AMAZING",
		Connector:             func(context.Context, Connection) error { return nil },
		GenerateSubscriptions: ws.GenerateSubs,
		Subscriber: func(ctx context.Context, c Connection, s subscription.List) error {
			return currySimpleSubConn(multi)(ctx, c, s)
		},
		Unsubscriber: func(ctx context.Context, c Connection, s subscription.List) error {
			return currySimpleUnsubConn(multi)(ctx, c, s)
		},
		Handler: func(context.Context, []byte) error { return nil },
	}
	require.NoError(t, multi.SetupNewConnection(amazingCandidate))

	amazingConn := multi.getConnectionFromSetup(amazingCandidate)
	multi.connections = map[Connection]*ConnectionWrapper{
		amazingConn: &multi.connectionManager[0],
	}

	subs, err = amazingCandidate.GenerateSubscriptions()
	require.NoError(t, err, "Generating test subscriptions should not error")
	assert.NoError(t, new(Websocket).UnsubscribeChannels(nil, subs), "Should not error when w.subscriptions is nil")
	assert.NoError(t, new(Websocket).UnsubscribeChannels(amazingConn, subs), "Should not error when w.subscriptions is nil")
	assert.NoError(t, multi.UnsubscribeChannels(amazingConn, nil), "Unsubscribing from nil should not error")
	assert.ErrorIs(t, multi.UnsubscribeChannels(amazingConn, subs), subscription.ErrNotFound, "Unsubscribing should error when not subscribed")
	assert.Nil(t, multi.GetSubscription(42), "GetSubscription on empty internal map should return")

	assert.ErrorIs(t, multi.SubscribeToChannels(nil, subs), common.ErrNilPointer, "If no connection is set, Subscribe should error")

	assert.NoError(t, multi.SubscribeToChannels(amazingConn, subs), "Basic Subscribing should not error")
	assert.Len(t, multi.GetSubscriptions(), 4, "Should have 4 subscriptions")
	bySub = multi.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, multi.GetSubscription("purple"), "GetSubscription by string key should find a channel") {
		assert.Equal(t, "TestSub2", multi.GetSubscription("purple").Channel, "GetSubscription by string key should return a pointer a copy of the right channel")
	}
	if assert.NotNil(t, multi.GetSubscription(testSubKey{"mauve"}), "GetSubscription by type key should find a channel") {
		assert.Equal(t, "TestSub3", multi.GetSubscription(testSubKey{"mauve"}).Channel, "GetSubscription by type key should return a pointer a copy of the right channel")
	}
	if assert.NotNil(t, multi.GetSubscription(42), "GetSubscription by int key should find a channel") {
		assert.Equal(t, "TestSub4", multi.GetSubscription(42).Channel, "GetSubscription by int key should return a pointer a copy of the right channel")
	}
	assert.Nil(t, multi.GetSubscription(nil), "GetSubscription by nil should return nil")
	assert.Nil(t, multi.GetSubscription(45), "GetSubscription by invalid key should return nil")
	assert.ErrorIs(t, multi.SubscribeToChannels(amazingConn, subs), subscription.ErrDuplicate, "Subscribe should error when already subscribed")
	assert.NoError(t, multi.SubscribeToChannels(amazingConn, nil), "Subscribe to an nil List should not error")
	assert.NoError(t, multi.UnsubscribeChannels(amazingConn, subs), "Unsubscribing should not error")

	amazingCandidate.Subscriber = func(context.Context, Connection, subscription.List) error { return errDastardlyReason }
	assert.ErrorIs(t, multi.SubscribeToChannels(amazingConn, subs), errDastardlyReason, "Should error correctly when error returned from Subscriber")

	err = multi.SubscribeToChannels(amazingConn, 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(nil, channel[0]), subscription.ErrNotFound, "Resubscribe should error when channel isn't subscribed yet")
	assert.NoError(t, ws.SubscribeToChannels(nil, channel), "Subscribe should not error")
	assert.NoError(t, ws.ResubscribeToChannel(nil, 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(nil, 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(nil, s), subscription.ErrDuplicate, "Adding same subscription should return error")
	assert.Equal(t, subscription.SubscribingState, s.State(), "Should set state to Subscribing")

	err := w.RemoveSubscriptions(nil, 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(nil, 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, nil), common.ErrNilPointer, "Should error correctly when nil websocket")
	c := &subscription.Subscription{Key: 42, Channel: subscription.TickerChannel}
	require.NoError(t, w.AddSuccessfulSubscriptions(nil, 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(nil, 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(nil, c), subscription.ErrDuplicate, "Adding same subscription should return error")

	err := w.RemoveSubscriptions(nil, 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(nil, c), subscription.ErrNotFound, "Should error correctly when not found")
	assert.ErrorIs(t, (*Websocket)(nil).RemoveSubscriptions(nil, nil), common.ErrNilPointer, "Should error correctly when nil websocket")
	w.subscriptions = nil
	assert.ErrorIs(t, w.RemoveSubscriptions(nil, c), common.ErrNilPointer, "Should error correctly when nil websocket")
}

// 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(nil, 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(nil, 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()

	mock := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) { mockws.WsMockUpgrader(t, w, r, mockws.EchoHandler) }))
	defer mock.Close()

	var testCases = []testStruct{
		{
			WC: WebsocketConnection{
				ExchangeName:     "test1",
				Verbose:          true,
				URL:              "ws" + mock.URL[len("http"):] + "/ws",
				RateLimit:        request.NewWeightedRateLimitByDuration(10 * time.Millisecond),
				ResponseMaxLimit: 7000000000,
			},
		},
		{
			Error: errors.New(" Error: malformed ws or wss URL"),
			WC: WebsocketConnection{
				ExchangeName:     "test2",
				Verbose:          true,
				URL:              "",
				ResponseMaxLimit: 7000000000,
			},
		},
		{
			WC: WebsocketConnection{
				ExchangeName:     "test3",
				Verbose:          true,
				URL:              "ws" + mock.URL[len("http"):] + "/ws",
				ProxyURL:         proxyURL,
				ResponseMaxLimit: 7000000000,
			},
		},
	}
	// Mock server rejects parallel connections
	for i := range testCases {
		if testCases[i].WC.ProxyURL != "" && !useProxyTests {
			t.Log("Proxy testing not enabled, skipping")
			continue
		}
		err := testCases[i].WC.Dial(&websocket.Dialer{}, http.Header{})
		if err != nil {
			if testCases[i].Error != nil && strings.Contains(err.Error(), testCases[i].Error.Error()) {
				return
			}
			t.Fatal(err)
		}
	}
}

// TestSendMessage logic test
func TestSendMessage(t *testing.T) {
	t.Parallel()

	mock := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) { mockws.WsMockUpgrader(t, w, r, mockws.EchoHandler) }))
	defer mock.Close()

	var testCases = []testStruct{
		{
			WC: WebsocketConnection{
				ExchangeName:     "test1",
				Verbose:          true,
				URL:              "ws" + mock.URL[len("http"):] + "/ws",
				RateLimit:        request.NewWeightedRateLimitByDuration(10 * time.Millisecond),
				ResponseMaxLimit: 7000000000,
			},
		},
		{
			Error: errors.New(" Error: malformed ws or wss URL"),
			WC: WebsocketConnection{
				ExchangeName:     "test2",
				Verbose:          true,
				URL:              "",
				ResponseMaxLimit: 7000000000,
			},
		},
		{
			WC: WebsocketConnection{
				ExchangeName:     "test3",
				Verbose:          true,
				URL:              "ws" + mock.URL[len("http"):] + "/ws",
				ProxyURL:         proxyURL,
				ResponseMaxLimit: 7000000000,
			},
		},
	}
	// Mock server rejects parallel connections
	for x := range testCases {
		if testCases[x].WC.ProxyURL != "" && !useProxyTests {
			t.Log("Proxy testing not enabled, skipping")
			continue
		}
		err := testCases[x].WC.Dial(&websocket.Dialer{}, http.Header{})
		if err != nil {
			if testCases[x].Error != nil && strings.Contains(err.Error(), testCases[x].Error.Error()) {
				return
			}
			t.Fatal(err)
		}
		err = testCases[x].WC.SendJSONMessage(context.Background(), request.Unset, Ping)
		require.NoError(t, err)
		err = testCases[x].WC.SendRawMessage(context.Background(), request.Unset, websocket.TextMessage, []byte(Ping))
		require.NoError(t, err)
	}
}

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

	mock := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) { mockws.WsMockUpgrader(t, w, r, mockws.EchoHandler) }))
	defer mock.Close()

	wc := &WebsocketConnection{
		Verbose:          true,
		URL:              "ws" + mock.URL[len("http"):] + "/ws",
		ResponseMaxLimit: time.Second * 5,
		Match:            NewMatch(),
	}
	if wc.ProxyURL != "" && !useProxyTests {
		t.Skip("Proxy testing not enabled, skipping")
	}

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

	go readMessages(t, wc)

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

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

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

	// with timeout
	wc.ResponseMaxLimit = 1
	_, err = wc.SendMessageReturnResponse(context.Background(), request.Unset, "123", req)
	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()

	mock := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) { mockws.WsMockUpgrader(t, w, r, mockws.EchoHandler) }))
	defer mock.Close()

	wc := &WebsocketConnection{
		URL:              "ws" + mock.URL[len("http"):] + "/ws",
		ResponseMaxLimit: time.Second * 5,
		Match:            NewMatch(),
		Wg:               &sync.WaitGroup{},
	}

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

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

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

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

// TestParseBinaryResponse logic test
func TestParseBinaryResponse(t *testing.T) {
	t.Parallel()

	mock := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) { mockws.WsMockUpgrader(t, w, r, mockws.EchoHandler) }))
	defer mock.Close()

	wc := &WebsocketConnection{
		URL:              "ws" + mock.URL[len("http"):] + "/ws",
		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
	}

	wc.bespokeGenerateMessageID = func(bool) int64 { return 42 }
	assert.EqualValues(t, 42, wc.GenerateMessageID(true), "GenerateMessageID must use bespokeGenerateMessageID")
}

// 7002502	       166.7 ns/op	      48 B/op	       3 allocs/op
func BenchmarkGenerateMessageID_High(b *testing.B) {
	wc := WebsocketConnection{}
	for i := 0; i < b.N; i++ {
		_ = wc.GenerateMessageID(true)
	}
}

// 6536250	       186.1 ns/op	      48 B/op	       3 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(nil, subscription.List{}) }, "Should not panic when called without a store")
	subs, unsubs := w.GetChannelDifference(nil, 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(nil, subs...), "AddSubscriptions must not error")
	subs, unsubs = w.GetChannelDifference(nil, 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")

	w = &Websocket{}
	sweetConn := &WebsocketConnection{}
	subs, unsubs = w.GetChannelDifference(sweetConn, subscription.List{{Channel: subscription.CandlesChannel}})
	require.Equal(t, 1, len(subs))
	require.Empty(t, unsubs, "Should get no unsubs")

	w.connections = map[Connection]*ConnectionWrapper{
		sweetConn: {Setup: &ConnectionSetup{URL: "ws://localhost:8080/ws"}},
	}

	naughtyConn := &WebsocketConnection{}
	subs, unsubs = w.GetChannelDifference(naughtyConn, subscription.List{{Channel: subscription.CandlesChannel}})
	require.Equal(t, 1, len(subs))
	require.Empty(t, unsubs, "Should get no unsubs")

	subs, unsubs = w.GetChannelDifference(sweetConn, subscription.List{{Channel: subscription.CandlesChannel}})
	require.Equal(t, 1, len(subs))
	require.Empty(t, unsubs, "Should get no unsubs")

	err := w.connections[sweetConn].Subscriptions.Add(&subscription.Subscription{Channel: subscription.CandlesChannel})
	require.NoError(t, err)

	subs, unsubs = w.GetChannelDifference(sweetConn, subscription.List{{Channel: subscription.CandlesChannel}})
	require.Empty(t, subs, "Should get no subs")
	require.Empty(t, unsubs, "Should get no unsubs")

	subs, unsubs = w.GetChannelDifference(sweetConn, nil)
	require.Empty(t, subs, "Should get no subs")
	require.Equal(t, 1, len(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

	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")

	newgen := GenSubs{EnabledPairs: []currency.Pair{
		currency.NewPair(currency.BTC, currency.AUD),
		currency.NewPair(currency.BTC, currency.USDT),
	}}

	w := NewWebsocket()
	w.exchangeName = "test"
	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)

	// Allow subscribe and unsubscribe feature set, without these the tests will call shutdown and connect.
	w.features.Subscribe = true
	w.features.Unsubscribe = true

	// 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.GenerateSubs = func() (subscription.List, error) { return nil, errDastardlyReason } // error on generateSubs
	err = w.FlushChannels()                                                               // error on full subscribeToChannels
	assert.ErrorIs(t, err, errDastardlyReason, "FlushChannels should error correctly on GenerateSubs")

	w.GenerateSubs = func() (subscription.List, error) { return nil, nil } // No subs to sub
	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(nil, subs...), "AddSubscriptions must not error")
	err = w.FlushChannels()
	assert.NoError(t, err, "FlushChannels should not error")

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

	// Multi connection management
	w.useMultiConnectionManagement = true
	mock := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) { mockws.WsMockUpgrader(t, w, r, mockws.EchoHandler) }))
	defer mock.Close()

	amazingCandidate := &ConnectionSetup{
		URL: "ws" + mock.URL[len("http"):] + "/ws",
		Connector: func(ctx context.Context, conn Connection) error {
			return conn.DialContext(ctx, websocket.DefaultDialer, nil)
		},
		GenerateSubscriptions: newgen.generateSubs,
		Subscriber: func(ctx context.Context, c Connection, s subscription.List) error {
			return currySimpleSubConn(w)(ctx, c, s)
		},
		Unsubscriber: func(ctx context.Context, c Connection, s subscription.List) error {
			return currySimpleUnsubConn(w)(ctx, c, s)
		},
		Handler: func(context.Context, []byte) error { return nil },
	}
	require.NoError(t, w.SetupNewConnection(amazingCandidate))
	require.NoError(t, w.FlushChannels(), "FlushChannels must not error")

	// Forces full connection cycle (shutdown, connect, subscribe). This will also start monitoring routines.
	w.features.Subscribe = false
	require.NoError(t, w.FlushChannels(), "FlushChannels must not error")

	// Unsubscribe what's already subscribed. No subscriptions left over, which then forces the shutdown and removal
	// of the connection from management.
	w.features.Subscribe = true
	w.connectionManager[0].Setup.GenerateSubscriptions = func() (subscription.List, error) { return nil, nil }
	require.NoError(t, w.FlushChannels(), "FlushChannels must 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{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")

	// Test connection candidates for multi connection tracking.
	multi := NewWebsocket()
	set := *defaultSetup
	set.UseMultiConnectionManagement = true
	require.NoError(t, multi.Setup(&set))

	err = multi.SetupNewConnection(nil)
	require.ErrorIs(t, err, errExchangeConfigEmpty)

	connSetup := &ConnectionSetup{ResponseCheckTimeout: time.Millisecond}
	err = multi.SetupNewConnection(connSetup)
	require.ErrorIs(t, err, errDefaultURLIsEmpty)

	connSetup.URL = "urlstring"
	err = multi.SetupNewConnection(connSetup)
	require.ErrorIs(t, err, errWebsocketConnectorUnset)

	connSetup.Connector = func(context.Context, Connection) error { return nil }
	err = multi.SetupNewConnection(connSetup)
	require.ErrorIs(t, err, errWebsocketSubscriptionsGeneratorUnset)

	connSetup.GenerateSubscriptions = func() (subscription.List, error) { return nil, nil }
	err = multi.SetupNewConnection(connSetup)
	require.ErrorIs(t, err, errWebsocketSubscriberUnset)

	connSetup.Subscriber = func(context.Context, Connection, subscription.List) error { return nil }
	err = multi.SetupNewConnection(connSetup)
	require.ErrorIs(t, err, errWebsocketUnsubscriberUnset)

	connSetup.Unsubscriber = func(context.Context, Connection, subscription.List) error { return nil }
	err = multi.SetupNewConnection(connSetup)
	require.ErrorIs(t, err, errWebsocketDataHandlerUnset)

	connSetup.Handler = func(context.Context, []byte) error { return nil }
	err = multi.SetupNewConnection(connSetup)
	require.NoError(t, err)

	require.Len(t, multi.connectionManager, 1)

	require.Nil(t, multi.AuthConn)
	require.Nil(t, multi.Conn)

	err = multi.SetupNewConnection(connSetup)
	require.ErrorIs(t, err, errConnectionWrapperDuplication)
}

func TestWebsocketConnectionShutdown(t *testing.T) {
	t.Parallel()
	wc := WebsocketConnection{shutdown: make(chan struct{})}
	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")

	mock := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) { mockws.WsMockUpgrader(t, w, r, mockws.EchoHandler) }))
	defer mock.Close()

	wc.URL = "ws" + mock.URL[len("http"):] + "/ws"

	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()

	mock := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) { mockws.WsMockUpgrader(t, w, r, mockws.EchoHandler) }))
	defer mock.Close()

	r := &reporter{}
	exch := "Kraken"
	wc := &WebsocketConnection{
		ExchangeName:     exch,
		Verbose:          true,
		URL:              "ws" + mock.URL[len("http"):] + "/ws",
		ResponseMaxLimit: time.Second * 1,
		Match:            NewMatch(),
		Reporter:         r,
	}
	if wc.ProxyURL != "" && !useProxyTests {
		t.Skip("Proxy testing not enabled, skipping")
	}

	err := wc.Dial(&websocket.Dialer{}, http.Header{})
	require.NoError(t, err)

	go readMessages(t, wc)

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

	_, err = wc.SendMessageReturnResponse(context.Background(), request.Unset, req.RequestID, req)
	require.NoError(t, err)
	require.NotEmpty(t, r.t, "Latency should have a duration")
	require.Equal(t, exch, r.name, "Latency should have the correct exchange name")
}

func TestCheckSubscriptions(t *testing.T) {
	t.Parallel()
	ws := Websocket{}
	err := ws.checkSubscriptions(nil, 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, nil)
	assert.NoError(t, err, "checkSubscriptions should not error on a nil list")

	ws.MaxSubscriptionsPerConnection = 1

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

	ws.subscriptions = subscription.NewStore()
	err = ws.checkSubscriptions(nil, 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(nil, subscription.List{{Key: 42, Channel: "test"}})
	assert.ErrorIs(t, err, subscription.ErrDuplicate, "checkSubscriptions should error correctly")

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

func TestRemoveURLQueryString(t *testing.T) {
	t.Parallel()
	assert.Equal(t, "https://www.google.com", removeURLQueryString("https://www.google.com?test=1"), "removeURLQueryString should remove query string")
	assert.Equal(t, "https://www.google.com", removeURLQueryString("https://www.google.com"), "removeURLQueryString should not change URL")
	assert.Equal(t, "", removeURLQueryString(""), "removeURLQueryString should be equal")
}

func TestWriteToConn(t *testing.T) {
	t.Parallel()
	wc := WebsocketConnection{}
	require.ErrorIs(t, wc.writeToConn(context.Background(), request.Unset, func() error { return nil }), errWebsocketIsDisconnected)
	wc.setConnectedStatus(true)
	// No rate limits set
	require.NoError(t, wc.writeToConn(context.Background(), request.Unset, func() error { return nil }))
	// connection rate limit set
	wc.RateLimit = request.NewWeightedRateLimitByDuration(time.Millisecond)
	require.NoError(t, wc.writeToConn(context.Background(), request.Unset, func() error { return nil }))
	ctx, cancel := context.WithTimeout(context.Background(), 0) // deadline exceeded
	cancel()
	require.ErrorIs(t, wc.writeToConn(ctx, request.Unset, func() error { return nil }), context.DeadlineExceeded)
	// definitions set but with fallover
	wc.RateLimitDefinitions = request.RateLimitDefinitions{
		request.Auth: request.NewWeightedRateLimitByDuration(time.Millisecond),
	}
	require.NoError(t, wc.writeToConn(context.Background(), request.Unset, func() error { return nil }))
	// match with global rate limit
	require.NoError(t, wc.writeToConn(context.Background(), request.Auth, func() error { return nil }))
	// definitions set but connection rate limiter not set
	wc.RateLimit = nil
	require.ErrorIs(t, wc.writeToConn(ctx, request.Unset, func() error { return nil }), errRateLimitNotFound)
}

func TestDrain(t *testing.T) {
	t.Parallel()
	drain(nil)
	ch := make(chan error)
	drain(ch)
	require.Empty(t, ch, "Drain should empty the channel")
	ch = make(chan error, 10)
	for range 10 {
		ch <- errors.New("test")
	}
	drain(ch)
	require.Empty(t, ch, "Drain should empty the channel")
}

func TestMonitorFrame(t *testing.T) {
	t.Parallel()
	ws := Websocket{}
	require.Panics(t, func() { ws.monitorFrame(nil, nil) }, "monitorFrame must panic on nil frame")
	require.Panics(t, func() { ws.monitorFrame(nil, func() func() bool { return nil }) }, "monitorFrame must panic on nil function")
	ws.Wg.Add(1)
	ws.monitorFrame(&ws.Wg, func() func() bool { return func() bool { return true } })
	ws.Wg.Wait()
}

func TestMonitorData(t *testing.T) {
	t.Parallel()
	ws := Websocket{ShutdownC: make(chan struct{}), DataHandler: make(chan interface{}, 10)}
	// Handle shutdown signal
	close(ws.ShutdownC)
	require.True(t, ws.observeData(nil))
	ws.ShutdownC = make(chan struct{})
	// Handle blockage of ToRoutine
	go func() { ws.DataHandler <- nil }()
	var dropped int
	require.False(t, ws.observeData(&dropped))
	require.Equal(t, 1, dropped)
	// Handle reinstate of ToRoutine functionality which will reset dropped counter
	ws.ToRoutine = make(chan interface{}, 10)
	go func() { ws.DataHandler <- nil }()
	require.False(t, ws.observeData(&dropped))
	require.Empty(t, dropped)
	// Handle outer closure shell
	innerShell := ws.monitorData()
	go func() { ws.DataHandler <- nil }()
	require.False(t, innerShell())
	// Handle shutdown signal
	close(ws.ShutdownC)
	require.True(t, innerShell())
}

func TestMonitorConnection(t *testing.T) {
	t.Parallel()
	ws := Websocket{verbose: true, ReadMessageErrors: make(chan error, 1), ShutdownC: make(chan struct{})}
	// Handle timer expired and websocket disabled, shutdown everything.
	timer := time.NewTimer(0)
	ws.setState(connectedState)
	ws.connectionMonitorRunning.Store(true)
	require.True(t, ws.observeConnection(timer))
	require.False(t, ws.connectionMonitorRunning.Load())
	require.Equal(t, disconnectedState, ws.state.Load())
	// Handle timer expired and everything is great, reset the timer.
	ws.setEnabled(true)
	ws.setState(connectedState)
	ws.connectionMonitorRunning.Store(true)
	timer = time.NewTimer(0)
	require.False(t, ws.observeConnection(timer)) // Not shutting down
	// Handle timer expired and for reason its not connected, so lets happily connect again.
	ws.setState(disconnectedState)
	require.False(t, ws.observeConnection(timer)) // Connect is intentionally erroring
	// Handle error from a connection which will then trigger a reconnect
	ws.setState(connectedState)
	ws.DataHandler = make(chan interface{}, 1)
	ws.ReadMessageErrors <- errConnectionFault
	timer = time.NewTimer(time.Second)
	require.False(t, ws.observeConnection(timer))
	payload := <-ws.DataHandler
	err, ok := payload.(error)
	require.True(t, ok)
	require.ErrorIs(t, err, errConnectionFault)
	// Handle outta closure shell
	innerShell := ws.monitorConnection()
	ws.setState(connectedState)
	ws.ReadMessageErrors <- errConnectionFault
	require.False(t, innerShell())
}

func TestMonitorTraffic(t *testing.T) {
	t.Parallel()
	ws := Websocket{verbose: true, ShutdownC: make(chan struct{}), TrafficAlert: make(chan struct{}, 1)}
	ws.Wg.Add(1)
	// Handle external shutdown signal
	timer := time.NewTimer(time.Second)
	close(ws.ShutdownC)
	require.True(t, ws.observeTraffic(timer))
	// Handle timer expired but system is connecting, so reset the timer
	ws.ShutdownC = make(chan struct{})
	ws.setState(connectingState)
	timer = time.NewTimer(0)
	require.False(t, ws.observeTraffic(timer))
	// Handle timer expired and system is connected and has traffic within time window
	ws.setState(connectedState)
	timer = time.NewTimer(0)
	ws.TrafficAlert <- struct{}{}
	require.False(t, ws.observeTraffic(timer))
	// Handle timer expired and system is connected but no traffic within time window, causes shutdown to occur.
	timer = time.NewTimer(0)
	require.True(t, ws.observeTraffic(timer))
	ws.Wg.Done()
	// Shutdown is done in a routine, so we need to wait for it to finish
	require.Eventually(t, func() bool { return disconnectedState == ws.state.Load() }, time.Second, time.Millisecond)
	// Handle outer closure shell
	innerShell := ws.monitorTraffic()
	ws.m.Lock()
	ws.ShutdownC = make(chan struct{})
	ws.m.Unlock()
	ws.setState(connectedState)
	ws.TrafficAlert <- struct{}{}
	require.False(t, innerShell())
}