// SPDX-FileCopyrightText: 2023 The Pion community <https://pion.ly>
// SPDX-License-Identifier: MIT

//go:build !js
// +build !js

package webrtc

//
import (
	"context"
	"io"
	"sync/atomic"
	"testing"
	"time"

	"github.com/pion/interceptor"
	mock_interceptor "github.com/pion/interceptor/pkg/mock"
	"github.com/pion/rtcp"
	"github.com/pion/rtp"
	"github.com/pion/transport/v3/test"
	"github.com/pion/webrtc/v4/pkg/media"
	"github.com/stretchr/testify/assert"
)

// E2E test of the features of Interceptors
// * Assert an extension can be set on an outbound packet
// * Assert an extension can be read on an outbound packet
// * Assert that attributes set by an interceptor are returned to the Reader.
func TestPeerConnection_Interceptor(t *testing.T) {
	to := test.TimeOut(time.Second * 20)
	defer to.Stop()

	report := test.CheckRoutines(t)
	defer report()

	createPC := func() *PeerConnection {
		ir := &interceptor.Registry{}
		ir.Add(&mock_interceptor.Factory{
			NewInterceptorFn: func(_ string) (interceptor.Interceptor, error) {
				return &mock_interceptor.Interceptor{
					BindLocalStreamFn: func(_ *interceptor.StreamInfo, writer interceptor.RTPWriter) interceptor.RTPWriter {
						return interceptor.RTPWriterFunc(
							func(header *rtp.Header, payload []byte, attributes interceptor.Attributes) (int, error) {
								// set extension on outgoing packet
								header.Extension = true
								header.ExtensionProfile = 0xBEDE
								assert.NoError(t, header.SetExtension(2, []byte("foo")))

								return writer.Write(header, payload, attributes)
							},
						)
					},
					BindRemoteStreamFn: func(_ *interceptor.StreamInfo, reader interceptor.RTPReader) interceptor.RTPReader {
						return interceptor.RTPReaderFunc(func(b []byte, a interceptor.Attributes) (int, interceptor.Attributes, error) {
							if a == nil {
								a = interceptor.Attributes{}
							}

							a.Set("attribute", "value")

							return reader.Read(b, a)
						})
					},
				}, nil
			},
		})

		pc, err := NewAPI(WithInterceptorRegistry(ir)).NewPeerConnection(Configuration{})
		assert.NoError(t, err)

		return pc
	}

	offerer := createPC()
	answerer := createPC()

	track, err := NewTrackLocalStaticSample(RTPCodecCapability{MimeType: MimeTypeVP8}, "video", "pion")
	assert.NoError(t, err)

	_, err = offerer.AddTrack(track)
	assert.NoError(t, err)

	seenRTP, seenRTPCancel := context.WithCancel(context.Background())
	answerer.OnTrack(func(track *TrackRemote, _ *RTPReceiver) {
		p, attributes, readErr := track.ReadRTP()
		assert.NoError(t, readErr)

		assert.Equal(t, p.Extension, true)
		assert.Equal(t, "foo", string(p.GetExtension(2)))
		assert.Equal(t, "value", attributes.Get("attribute"))

		seenRTPCancel()
	})

	assert.NoError(t, signalPair(offerer, answerer))

	func() {
		ticker := time.NewTicker(time.Millisecond * 20)
		defer ticker.Stop()
		for {
			select {
			case <-seenRTP.Done():
				return
			case <-ticker.C:
				assert.NoError(t, track.WriteSample(media.Sample{Data: []byte{0x00}, Duration: time.Second}))
			}
		}
	}()

	closePairNow(t, offerer, answerer)
}

func Test_Interceptor_BindUnbind(t *testing.T) { //nolint:cyclop
	lim := test.TimeOut(time.Second * 10)
	defer lim.Stop()

	report := test.CheckRoutines(t)
	defer report()

	var (
		cntBindRTCPReader     uint32
		cntBindRTCPWriter     uint32
		cntBindLocalStream    uint32
		cntUnbindLocalStream  uint32
		cntBindRemoteStream   uint32
		cntUnbindRemoteStream uint32
		cntClose              uint32
	)
	mockInterceptor := &mock_interceptor.Interceptor{
		BindRTCPReaderFn: func(reader interceptor.RTCPReader) interceptor.RTCPReader {
			atomic.AddUint32(&cntBindRTCPReader, 1)

			return reader
		},
		BindRTCPWriterFn: func(writer interceptor.RTCPWriter) interceptor.RTCPWriter {
			atomic.AddUint32(&cntBindRTCPWriter, 1)

			return writer
		},
		BindLocalStreamFn: func(_ *interceptor.StreamInfo, writer interceptor.RTPWriter) interceptor.RTPWriter {
			atomic.AddUint32(&cntBindLocalStream, 1)

			return writer
		},
		UnbindLocalStreamFn: func(*interceptor.StreamInfo) {
			atomic.AddUint32(&cntUnbindLocalStream, 1)
		},
		BindRemoteStreamFn: func(_ *interceptor.StreamInfo, reader interceptor.RTPReader) interceptor.RTPReader {
			atomic.AddUint32(&cntBindRemoteStream, 1)

			return reader
		},
		UnbindRemoteStreamFn: func(_ *interceptor.StreamInfo) {
			atomic.AddUint32(&cntUnbindRemoteStream, 1)
		},
		CloseFn: func() error {
			atomic.AddUint32(&cntClose, 1)

			return nil
		},
	}
	ir := &interceptor.Registry{}
	ir.Add(&mock_interceptor.Factory{
		NewInterceptorFn: func(_ string) (interceptor.Interceptor, error) { return mockInterceptor, nil },
	})

	sender, receiver, err := NewAPI(WithInterceptorRegistry(ir)).newPair(Configuration{})
	assert.NoError(t, err)

	track, err := NewTrackLocalStaticSample(RTPCodecCapability{MimeType: MimeTypeVP8}, "video", "pion")
	assert.NoError(t, err)

	_, err = sender.AddTrack(track)
	assert.NoError(t, err)

	receiverReady, receiverReadyFn := context.WithCancel(context.Background())
	receiver.OnTrack(func(track *TrackRemote, _ *RTPReceiver) {
		_, _, readErr := track.ReadRTP()
		assert.NoError(t, readErr)
		receiverReadyFn()
	})

	assert.NoError(t, signalPair(sender, receiver))

	ticker := time.NewTicker(time.Millisecond * 20)
	defer ticker.Stop()
	func() {
		for {
			select {
			case <-receiverReady.Done():
				return
			case <-ticker.C:
				// Send packet to make receiver track actual creates RTPReceiver.
				assert.NoError(t, track.WriteSample(media.Sample{Data: []byte{0xAA}, Duration: time.Second}))
			}
		}
	}()

	assert.NoError(t, sender.GracefulClose())
	assert.NoError(t, receiver.GracefulClose())

	// Bind/UnbindLocal/RemoteStream should be called from one side.
	assert.Equal(t, uint32(1), atomic.LoadUint32(&cntBindLocalStream), "BindLocalStreamFn is expected to be called once")
	assert.Equal(
		t, uint32(1), atomic.LoadUint32(&cntUnbindLocalStream), "UnbindLocalStreamFn is expected to be called once",
	)
	assert.Equal(
		t, uint32(2), atomic.LoadUint32(&cntBindRemoteStream), "BindRemoteStreamFn is expected to be called twice",
	)
	assert.Equal(
		t, uint32(2), atomic.LoadUint32(&cntUnbindRemoteStream), "UnbindRemoteStreamFn is expected to be called twice",
	)

	// BindRTCPWriter/Reader and Close should be called from both side.
	assert.Equal(t, uint32(2), atomic.LoadUint32(&cntBindRTCPWriter), "BindRTCPWriterFn is expected to be called twice")
	assert.Equal(t, uint32(3), atomic.LoadUint32(&cntBindRTCPReader), "BindRTCPReaderFn is expected to be called thrice")
	assert.Equal(t, uint32(2), atomic.LoadUint32(&cntClose), "CloseFn is expected to be called twice")
}

func Test_InterceptorRegistry_Build(t *testing.T) {
	registryBuildCount := 0

	ir := &interceptor.Registry{}
	ir.Add(&mock_interceptor.Factory{
		NewInterceptorFn: func(_ string) (interceptor.Interceptor, error) {
			registryBuildCount++

			return &interceptor.NoOp{}, nil
		},
	})

	peerConnectionA, peerConnectionB, err := NewAPI(WithInterceptorRegistry(ir)).newPair(Configuration{})
	assert.NoError(t, err)

	assert.Equal(t, 2, registryBuildCount)
	closePairNow(t, peerConnectionA, peerConnectionB)
}

func Test_Interceptor_ZeroSSRC(t *testing.T) {
	to := test.TimeOut(time.Second * 20)
	defer to.Stop()

	report := test.CheckRoutines(t)
	defer report()

	track, err := NewTrackLocalStaticRTP(RTPCodecCapability{MimeType: MimeTypeVP8}, "video", "pion")
	assert.NoError(t, err)

	offerer, answerer, err := newPair()
	assert.NoError(t, err)

	_, err = offerer.AddTrack(track)
	assert.NoError(t, err)

	probeReceiverCreated := make(chan struct{})

	go func() {
		sequenceNumber := uint16(0)
		ticker := time.NewTicker(time.Millisecond * 20)
		defer ticker.Stop()
		for range ticker.C {
			track.mu.Lock()
			if len(track.bindings) == 1 {
				_, err = track.bindings[0].writeStream.WriteRTP(&rtp.Header{
					Version:        2,
					SSRC:           0,
					SequenceNumber: sequenceNumber,
				}, []byte{0, 1, 2, 3, 4, 5})
				assert.NoError(t, err)
			}
			sequenceNumber++
			track.mu.Unlock()

			if nonMediaBandwidthProbe, ok := answerer.nonMediaBandwidthProbe.Load().(*RTPReceiver); ok {
				assert.Equal(t, len(nonMediaBandwidthProbe.Tracks()), 1)
				close(probeReceiverCreated)

				return
			}
		}
	}()

	assert.NoError(t, signalPair(offerer, answerer))

	peerConnectionConnected := untilConnectionState(PeerConnectionStateConnected, offerer, answerer)
	peerConnectionConnected.Wait()

	<-probeReceiverCreated
	closePairNow(t, offerer, answerer)
}

// TestInterceptorNack is an end-to-end test for the NACK sender.
// It tests that:
//   - we get a NACK if we negotiated generic NACks;
//   - we don't get a NACK if we did not negotiate generick NACKs;
//   - the NACK corresponds to the missing packet.
func TestInterceptorNack(t *testing.T) {
	to := test.TimeOut(time.Second * 20)
	defer to.Stop()

	t.Run("Nack", func(t *testing.T) { testInterceptorNack(t, true) })
	t.Run("NoNack", func(t *testing.T) { testInterceptorNack(t, false) })
}

func testInterceptorNack(t *testing.T, requestNack bool) { //nolint:cyclop
	t.Helper()

	const numPackets = 20

	ir := interceptor.Registry{}
	mediaEngine := MediaEngine{}
	var feedback []RTCPFeedback
	if requestNack {
		feedback = append(feedback, RTCPFeedback{"nack", ""})
	}
	err := mediaEngine.RegisterCodec(
		RTPCodecParameters{
			RTPCodecCapability: RTPCodecCapability{
				"video/VP8", 90000, 0,
				"",
				feedback,
			},
			PayloadType: 96,
		},
		RTPCodecTypeVideo,
	)
	assert.NoError(t, err)
	api := NewAPI(
		WithMediaEngine(&mediaEngine),
		WithInterceptorRegistry(&ir),
	)

	pc1, err := api.NewPeerConnection(Configuration{})
	assert.NoError(t, err)

	pc1Connected := make(chan struct{})
	pc1.OnConnectionStateChange(func(state PeerConnectionState) {
		if state == PeerConnectionStateConnected {
			close(pc1Connected)
		}
	})

	track1, err := NewTrackLocalStaticRTP(
		RTPCodecCapability{MimeType: MimeTypeVP8},
		"video", "pion",
	)
	assert.NoError(t, err)
	sender, err := pc1.AddTrack(track1)
	assert.NoError(t, err)

	pc2, err := NewPeerConnection(Configuration{})
	assert.NoError(t, err)

	offer, err := pc1.CreateOffer(nil)
	assert.NoError(t, err)
	err = pc1.SetLocalDescription(offer)
	assert.NoError(t, err)
	<-GatheringCompletePromise(pc1)

	err = pc2.SetRemoteDescription(*pc1.LocalDescription())
	assert.NoError(t, err)
	answer, err := pc2.CreateAnswer(nil)
	assert.NoError(t, err)
	err = pc2.SetLocalDescription(answer)
	assert.NoError(t, err)
	<-GatheringCompletePromise(pc2)

	err = pc1.SetRemoteDescription(*pc2.LocalDescription())
	assert.NoError(t, err)

	<-pc1Connected

	var gotNack bool
	rtcpDone := make(chan struct{})
	go func() {
		defer close(rtcpDone)
		buf := make([]byte, 1500)
		for {
			n, _, err2 := sender.Read(buf)
			// nolint
			if err2 == io.EOF {
				break
			}
			assert.NoError(t, err2)
			ps, err2 := rtcp.Unmarshal(buf[:n])
			assert.NoError(t, err2)
			for _, p := range ps {
				if pn, ok := p.(*rtcp.TransportLayerNack); ok {
					assert.Equal(t, len(pn.Nacks), 1)
					assert.Equal(t,
						pn.Nacks[0].PacketID, uint16(1),
					)
					assert.Equal(t,
						pn.Nacks[0].LostPackets,
						rtcp.PacketBitmap(0),
					)
					gotNack = true
				}
			}
		}
	}()

	done := make(chan struct{})
	pc2.OnTrack(func(track2 *TrackRemote, _ *RTPReceiver) {
		for i := 0; i < numPackets; i++ {
			if i == 1 {
				continue
			}
			p, _, err2 := track2.ReadRTP()
			assert.NoError(t, err2)
			assert.Equal(t, p.SequenceNumber, uint16(i)) //nolint:gosec //G115
		}
		close(done)
	})

	go func() {
		for i := 0; i < numPackets; i++ {
			time.Sleep(20 * time.Millisecond)
			if i == 1 {
				continue
			}
			var p rtp.Packet
			p.Version = 2
			p.Marker = true
			p.PayloadType = 96
			p.SequenceNumber = uint16(i)         //nolint:gosec // G115
			p.Timestamp = uint32(i * 90000 / 50) //nolint:gosec // G115
			p.Payload = []byte{42}
			err2 := track1.WriteRTP(&p)
			assert.NoError(t, err2)
		}
	}()

	<-done
	err = pc1.Close()
	assert.NoError(t, err)
	err = pc2.Close()
	assert.NoError(t, err)

	if requestNack {
		assert.True(t, gotNack, "Expected to get a NACK, got none")
	} else {
		assert.False(t, gotNack, "Expected to get no NACK, got one")
	}
}