package webrtc

import (
	"bytes"
	"context"
	"io"
	"net/http"
	"net/url"
	"reflect"
	"testing"
	"time"

	"github.com/bluenviron/gortsplib/v5/pkg/description"
	"github.com/bluenviron/gortsplib/v5/pkg/format"
	"github.com/bluenviron/mediamtx/internal/conf"
	"github.com/bluenviron/mediamtx/internal/defs"
	"github.com/bluenviron/mediamtx/internal/externalcmd"
	"github.com/bluenviron/mediamtx/internal/protocols/webrtc"
	"github.com/bluenviron/mediamtx/internal/protocols/whip"
	"github.com/bluenviron/mediamtx/internal/stream"
	"github.com/bluenviron/mediamtx/internal/test"
	"github.com/bluenviron/mediamtx/internal/unit"
	"github.com/google/uuid"
	"github.com/pion/rtp"
	pwebrtc "github.com/pion/webrtc/v4"
	"github.com/stretchr/testify/require"
)

func ptrOf[T any](v T) *T {
	return &v
}

func checkClose(t *testing.T, closeFunc func() error) {
	require.NoError(t, closeFunc())
}

type dummyPath struct{}

func (p *dummyPath) Name() string {
	return "teststream"
}

func (p *dummyPath) SafeConf() *conf.Path {
	return &conf.Path{}
}

func (p *dummyPath) ExternalCmdEnv() externalcmd.Environment {
	return externalcmd.Environment{}
}

func (p *dummyPath) RemovePublisher(_ defs.PathRemovePublisherReq) {
}

func (p *dummyPath) RemoveReader(_ defs.PathRemoveReaderReq) {
}

func initializeTestServer(t *testing.T) *Server {
	pm := &test.PathManager{
		FindPathConfImpl: func(_ defs.PathFindPathConfReq) (*conf.Path, error) {
			return &conf.Path{}, nil
		},
	}

	s := &Server{
		Address:               "127.0.0.1:8886",
		Encryption:            false,
		ServerKey:             "",
		ServerCert:            "",
		AllowOrigin:           "*",
		TrustedProxies:        conf.IPNetworks{},
		ReadTimeout:           conf.Duration(10 * time.Second),
		LocalUDPAddress:       "127.0.0.1:8887",
		LocalTCPAddress:       "127.0.0.1:8887",
		IPsFromInterfaces:     true,
		IPsFromInterfacesList: []string{},
		AdditionalHosts:       []string{},
		ICEServers:            []conf.WebRTCICEServer{},
		HandshakeTimeout:      conf.Duration(10 * time.Second),
		TrackGatherTimeout:    conf.Duration(2 * time.Second),
		STUNGatherTimeout:     conf.Duration(5 * time.Second),
		ExternalCmdPool:       nil,
		PathManager:           pm,
		Parent:                test.NilLogger,
	}
	err := s.Initialize()
	require.NoError(t, err)

	return s
}

func TestServerStaticPages(t *testing.T) {
	s := initializeTestServer(t)
	defer s.Close()

	tr := &http.Transport{}
	defer tr.CloseIdleConnections()
	hc := &http.Client{Transport: tr}

	for _, path := range []string{"/stream", "/stream/publish", "/publish"} {
		func() {
			req, err := http.NewRequest(http.MethodGet, "http://myuser:mypass@localhost:8886"+path, nil)
			require.NoError(t, err)

			res, err := hc.Do(req)
			require.NoError(t, err)
			defer res.Body.Close()

			require.Equal(t, http.StatusOK, res.StatusCode)
		}()
	}
}

func TestPreflightRequest(t *testing.T) {
	s := initializeTestServer(t)
	defer s.Close()

	tr := &http.Transport{}
	defer tr.CloseIdleConnections()
	hc := &http.Client{Transport: tr}

	req, err := http.NewRequest(http.MethodOptions, "http://localhost:8886", nil)
	require.NoError(t, err)

	req.Header.Add("Access-Control-Request-Method", "GET")

	res, err := hc.Do(req)
	require.NoError(t, err)
	defer res.Body.Close()

	require.Equal(t, http.StatusNoContent, res.StatusCode)

	byts, err := io.ReadAll(res.Body)
	require.NoError(t, err)

	require.Equal(t, "*", res.Header.Get("Access-Control-Allow-Origin"))
	require.Equal(t, "true", res.Header.Get("Access-Control-Allow-Credentials"))
	require.Equal(t, "OPTIONS, GET, POST, PATCH, DELETE", res.Header.Get("Access-Control-Allow-Methods"))
	require.Equal(t, "Authorization, Content-Type, If-Match", res.Header.Get("Access-Control-Allow-Headers"))
	require.Equal(t, byts, []byte{})
}

func TestServerOptionsICEServer(t *testing.T) {
	pathManager := &test.PathManager{
		FindPathConfImpl: func(_ defs.PathFindPathConfReq) (*conf.Path, error) {
			return &conf.Path{}, nil
		},
	}

	s := &Server{
		Address:               "127.0.0.1:8886",
		Encryption:            false,
		ServerKey:             "",
		ServerCert:            "",
		AllowOrigin:           "",
		TrustedProxies:        conf.IPNetworks{},
		ReadTimeout:           conf.Duration(10 * time.Second),
		LocalUDPAddress:       "127.0.0.1:8887",
		LocalTCPAddress:       "127.0.0.1:8887",
		IPsFromInterfaces:     true,
		IPsFromInterfacesList: []string{},
		AdditionalHosts:       []string{},
		ICEServers: []conf.WebRTCICEServer{{
			URL:      "example.com",
			Username: "myuser",
			Password: "mypass",
		}},
		HandshakeTimeout:   conf.Duration(10 * time.Second),
		TrackGatherTimeout: conf.Duration(2 * time.Second),
		STUNGatherTimeout:  conf.Duration(5 * time.Second),
		ExternalCmdPool:    nil,
		PathManager:        pathManager,
		Parent:             test.NilLogger,
	}
	err := s.Initialize()
	require.NoError(t, err)
	defer s.Close()

	tr := &http.Transport{}
	defer tr.CloseIdleConnections()
	hc := &http.Client{Transport: tr}

	req, err := http.NewRequest(http.MethodOptions,
		"http://myuser:mypass@localhost:8886/nonexisting/whep", nil)
	require.NoError(t, err)

	res, err := hc.Do(req)
	require.NoError(t, err)
	defer res.Body.Close()

	require.Equal(t, http.StatusNoContent, res.StatusCode)

	iceServers, err := whip.LinkHeaderUnmarshal(res.Header["Link"])
	require.NoError(t, err)

	require.Equal(t, []pwebrtc.ICEServer{{
		URLs:       []string{"example.com"},
		Username:   "myuser",
		Credential: "mypass",
	}}, iceServers)
}

func TestServerPublish(t *testing.T) {
	var strm *stream.Stream
	streamCreated := make(chan struct{})

	pathManager := &test.PathManager{
		FindPathConfImpl: func(req defs.PathFindPathConfReq) (*conf.Path, error) {
			require.Equal(t, "teststream", req.AccessRequest.Name)
			require.Equal(t, "param=value", req.AccessRequest.Query)
			require.Equal(t, "myuser", req.AccessRequest.Credentials.User)
			require.Equal(t, "mypass", req.AccessRequest.Credentials.Pass)
			return &conf.Path{}, nil
		},
		AddPublisherImpl: func(req defs.PathAddPublisherReq) (defs.Path, *stream.Stream, error) {
			require.Equal(t, "teststream", req.AccessRequest.Name)
			require.Equal(t, "param=value", req.AccessRequest.Query)
			require.True(t, req.AccessRequest.SkipAuth)

			strm = &stream.Stream{
				WriteQueueSize:     512,
				RTPMaxPayloadSize:  1450,
				Desc:               req.Desc,
				GenerateRTPPackets: true,
				Parent:             test.NilLogger,
			}
			err := strm.Initialize()
			require.NoError(t, err)

			close(streamCreated)

			return &dummyPath{}, strm, nil
		},
	}

	s := &Server{
		Address:               "127.0.0.1:8886",
		Encryption:            false,
		ServerKey:             "",
		ServerCert:            "",
		AllowOrigin:           "",
		TrustedProxies:        conf.IPNetworks{},
		ReadTimeout:           conf.Duration(10 * time.Second),
		LocalUDPAddress:       "127.0.0.1:8887",
		LocalTCPAddress:       "127.0.0.1:8887",
		IPsFromInterfaces:     true,
		IPsFromInterfacesList: []string{},
		AdditionalHosts:       []string{},
		ICEServers:            []conf.WebRTCICEServer{},
		HandshakeTimeout:      conf.Duration(10 * time.Second),
		TrackGatherTimeout:    conf.Duration(2 * time.Second),
		STUNGatherTimeout:     conf.Duration(5 * time.Second),
		ExternalCmdPool:       nil,
		PathManager:           pathManager,
		Parent:                test.NilLogger,
	}
	err := s.Initialize()
	require.NoError(t, err)
	defer s.Close()

	tr := &http.Transport{}
	defer tr.CloseIdleConnections()
	hc := &http.Client{Transport: tr}

	su, err := url.Parse("http://myuser:mypass@localhost:8886/teststream/whip?param=value")
	require.NoError(t, err)

	track := &webrtc.OutgoingTrack{
		Caps: pwebrtc.RTPCodecCapability{
			MimeType:    pwebrtc.MimeTypeH264,
			ClockRate:   90000,
			SDPFmtpLine: "level-asymmetry-allowed=1;packetization-mode=1;profile-level-id=42e01f",
		},
	}

	wc := &whip.Client{
		HTTPClient:     hc,
		URL:            su,
		Publish:        true,
		OutgoingTracks: []*webrtc.OutgoingTrack{track},
		Log:            test.NilLogger,
	}

	err = wc.Initialize(context.Background())
	require.NoError(t, err)
	defer checkClose(t, wc.Close)

	err = track.WriteRTP(&rtp.Packet{
		Header: rtp.Header{
			Version:        2,
			Marker:         true,
			PayloadType:    96,
			SequenceNumber: 123,
			Timestamp:      45343,
			SSRC:           563423,
		},
		Payload: []byte{1},
	})
	require.NoError(t, err)

	<-streamCreated

	reader := test.NilLogger

	recv := make(chan struct{})

	strm.AddReader(
		reader,
		strm.Desc.Medias[0],
		strm.Desc.Medias[0].Formats[0],
		func(u unit.Unit) error {
			select {
			case <-recv:
				return nil
			default:
			}

			require.Equal(t, [][]byte{
				{1},
			}, u.(*unit.H264).AU)
			close(recv)

			return nil
		})

	strm.StartReader(reader)
	defer strm.RemoveReader(reader)

	err = track.WriteRTP(&rtp.Packet{
		Header: rtp.Header{
			Version:        2,
			Marker:         true,
			PayloadType:    96,
			SequenceNumber: 124,
			Timestamp:      45343,
			SSRC:           563423,
		},
		Payload: []byte{1},
	})
	require.NoError(t, err)

	<-recv
}

func TestServerRead(t *testing.T) {
	for _, ca := range []struct {
		name          string
		medias        []*description.Media
		unit          unit.Unit
		outRTPPayload []byte
	}{
		{
			"av1",
			[]*description.Media{{
				Type: description.MediaTypeVideo,
				Formats: []format.Format{&format.AV1{
					PayloadTyp: 96,
				}},
			}},
			&unit.AV1{
				TU: [][]byte{{1, 2}},
			},
			[]byte{0x10, 0x01, 0x02},
		},
		{
			"vp9",
			[]*description.Media{{
				Type: description.MediaTypeVideo,
				Formats: []format.Format{&format.VP9{
					PayloadTyp: 96,
				}},
			}},
			&unit.VP9{
				Frame: []byte{0x82, 0x49, 0x83, 0x42, 0x0, 0x77, 0xf0, 0x32, 0x34},
			},
			[]byte{
				0x8f, 0xa0, 0xfd, 0x18, 0x07, 0x80, 0x03, 0x24,
				0x01, 0x14, 0x01, 0x82, 0x49, 0x83, 0x42, 0x00,
				0x77, 0xf0, 0x32, 0x34,
			},
		},
		{
			"vp8",
			[]*description.Media{{
				Type: description.MediaTypeVideo,
				Formats: []format.Format{&format.VP8{
					PayloadTyp: 96,
				}},
			}},
			&unit.VP8{
				Frame: []byte{1, 2},
			},
			[]byte{0x10, 1, 2},
		},
		{
			"h264",
			[]*description.Media{test.MediaH264},
			&unit.H264{
				AU: [][]byte{
					{5, 1},
				},
			},
			[]byte{
				0x18, 0x00, 0x19, 0x67, 0x42, 0xc0, 0x28, 0xd9,
				0x00, 0x78, 0x02, 0x27, 0xe5, 0x84, 0x00, 0x00,
				0x03, 0x00, 0x04, 0x00, 0x00, 0x03, 0x00, 0xf0,
				0x3c, 0x60, 0xc9, 0x20, 0x00, 0x04, 0x08, 0x06,
				0x07, 0x08, 0x00, 0x02, 0x05, 0x01,
			},
		},
		{
			"opus",
			[]*description.Media{{
				Type: description.MediaTypeAudio,
				Formats: []format.Format{&format.Opus{
					PayloadTyp:   96,
					ChannelCount: 2,
				}},
			}},
			&unit.Opus{
				Packets: [][]byte{{1, 2}},
			},
			[]byte{1, 2},
		},
		{
			"g722",
			[]*description.Media{{
				Type:    description.MediaTypeAudio,
				Formats: []format.Format{&format.G722{}},
			}},
			&unit.Generic{
				Base: unit.Base{
					RTPPackets: []*rtp.Packet{{
						Header: rtp.Header{
							Version:        2,
							Marker:         true,
							PayloadType:    9,
							SequenceNumber: 1123,
							Timestamp:      45343,
							SSRC:           563423,
						},
						Payload: []byte{1, 2},
					}},
				},
			},
			[]byte{1, 2},
		},
		{
			"g711 8khz mono",
			[]*description.Media{{
				Type: description.MediaTypeAudio,
				Formats: []format.Format{&format.G711{
					MULaw:        true,
					SampleRate:   8000,
					ChannelCount: 1,
				}},
			}},
			&unit.G711{
				Samples: []byte{1, 2, 3},
			},
			[]byte{1, 2, 3},
		},
		{
			"g711 16khz stereo",
			[]*description.Media{{
				Type: description.MediaTypeAudio,
				Formats: []format.Format{&format.G711{
					MULaw:        true,
					SampleRate:   16000,
					ChannelCount: 2,
				}},
			}},
			&unit.G711{
				Samples: []byte{1, 2, 3, 4},
			},
			[]byte{0x86, 0x84, 0x8a, 0x84, 0x8e, 0x84, 0x92, 0x84},
		},
		{
			"lpcm",
			[]*description.Media{{
				Type: description.MediaTypeAudio,
				Formats: []format.Format{&format.LPCM{
					PayloadTyp:   96,
					BitDepth:     16,
					SampleRate:   48000,
					ChannelCount: 2,
				}},
			}},
			&unit.LPCM{
				Samples: []byte{1, 2, 3, 4},
			},
			[]byte{1, 2, 3, 4},
		},
	} {
		t.Run(ca.name, func(t *testing.T) {
			desc := &description.Session{Medias: ca.medias}

			strm := &stream.Stream{
				WriteQueueSize:     512,
				RTPMaxPayloadSize:  1450,
				Desc:               desc,
				GenerateRTPPackets: reflect.TypeOf(ca.unit) != reflect.TypeOf(&unit.Generic{}),
				Parent:             test.NilLogger,
			}
			err := strm.Initialize()
			require.NoError(t, err)

			pathManager := &test.PathManager{
				FindPathConfImpl: func(req defs.PathFindPathConfReq) (*conf.Path, error) {
					require.Equal(t, "teststream", req.AccessRequest.Name)
					require.Equal(t, "param=value", req.AccessRequest.Query)
					require.Equal(t, "myuser", req.AccessRequest.Credentials.User)
					require.Equal(t, "mypass", req.AccessRequest.Credentials.Pass)
					return &conf.Path{}, nil
				},
				AddReaderImpl: func(req defs.PathAddReaderReq) (defs.Path, *stream.Stream, error) {
					require.Equal(t, "teststream", req.AccessRequest.Name)
					require.Equal(t, "param=value", req.AccessRequest.Query)
					require.Equal(t, "myuser", req.AccessRequest.Credentials.User)
					require.Equal(t, "mypass", req.AccessRequest.Credentials.Pass)
					return &dummyPath{}, strm, nil
				},
			}

			s := &Server{
				Address:               "127.0.0.1:8886",
				Encryption:            false,
				ServerKey:             "",
				ServerCert:            "",
				AllowOrigin:           "",
				TrustedProxies:        conf.IPNetworks{},
				ReadTimeout:           conf.Duration(10 * time.Second),
				LocalUDPAddress:       "127.0.0.1:8887",
				LocalTCPAddress:       "127.0.0.1:8887",
				IPsFromInterfaces:     true,
				IPsFromInterfacesList: []string{},
				AdditionalHosts:       []string{},
				ICEServers:            []conf.WebRTCICEServer{},
				HandshakeTimeout:      conf.Duration(10 * time.Second),
				TrackGatherTimeout:    conf.Duration(2 * time.Second),
				STUNGatherTimeout:     conf.Duration(5 * time.Second),
				ExternalCmdPool:       nil,
				PathManager:           pathManager,
				Parent:                test.NilLogger,
			}
			err = s.Initialize()
			require.NoError(t, err)
			defer s.Close()

			u, err := url.Parse("http://myuser:mypass@localhost:8886/teststream/whep?param=value")
			require.NoError(t, err)

			tr := &http.Transport{}
			defer tr.CloseIdleConnections()
			hc := &http.Client{Transport: tr}

			wc := &whip.Client{
				HTTPClient: hc,
				URL:        u,
				Log:        test.NilLogger,
			}

			writerDone := make(chan struct{})

			go func() {
				defer close(writerDone)

				strm.WaitRunningReader()

				r := reflect.New(reflect.TypeOf(ca.unit).Elem())
				r.Elem().Set(reflect.ValueOf(ca.unit).Elem())

				if g, ok := r.Interface().(*unit.Generic); ok {
					clone := *g.RTPPackets[0]
					strm.WriteRTPPacket(desc.Medias[0], desc.Medias[0].Formats[0], &clone, time.Time{}, 0)
				} else {
					strm.WriteUnit(desc.Medias[0], desc.Medias[0].Formats[0], r.Interface().(unit.Unit))
				}
			}()

			err = wc.Initialize(context.Background())
			require.NoError(t, err)
			defer checkClose(t, wc.Close)

			done := make(chan struct{})

			wc.IncomingTracks()[0].OnPacketRTP = func(pkt *rtp.Packet, _ time.Time) {
				select {
				case <-done:
				default:
					require.Equal(t, ca.outRTPPayload, pkt.Payload)
					close(done)
				}
			}

			wc.StartReading()

			<-writerDone
			<-done
		})
	}
}

func TestServerReadNotFound(t *testing.T) {
	pm := &test.PathManager{
		FindPathConfImpl: func(_ defs.PathFindPathConfReq) (*conf.Path, error) {
			return &conf.Path{}, nil
		},
		AddReaderImpl: func(_ defs.PathAddReaderReq) (defs.Path, *stream.Stream, error) {
			return nil, nil, defs.PathNoStreamAvailableError{}
		},
	}

	s := &Server{
		Address:               "127.0.0.1:8886",
		Encryption:            false,
		ServerKey:             "",
		ServerCert:            "",
		AllowOrigin:           "",
		TrustedProxies:        conf.IPNetworks{},
		ReadTimeout:           conf.Duration(10 * time.Second),
		LocalUDPAddress:       "127.0.0.1:8887",
		LocalTCPAddress:       "127.0.0.1:8887",
		IPsFromInterfaces:     true,
		IPsFromInterfacesList: []string{},
		AdditionalHosts:       []string{},
		ICEServers:            []conf.WebRTCICEServer{},
		HandshakeTimeout:      conf.Duration(10 * time.Second),
		TrackGatherTimeout:    conf.Duration(2 * time.Second),
		STUNGatherTimeout:     conf.Duration(5 * time.Second),
		ExternalCmdPool:       nil,
		PathManager:           pm,
		Parent:                test.NilLogger,
	}
	err := s.Initialize()
	require.NoError(t, err)
	defer s.Close()

	tr := &http.Transport{}
	defer tr.CloseIdleConnections()
	hc := &http.Client{Transport: tr}

	pc, err := pwebrtc.NewPeerConnection(pwebrtc.Configuration{})
	require.NoError(t, err)
	defer pc.GracefulClose() //nolint:errcheck

	_, err = pc.AddTransceiverFromKind(pwebrtc.RTPCodecTypeVideo)
	require.NoError(t, err)

	offer, err := pc.CreateOffer(nil)
	require.NoError(t, err)

	req, err := http.NewRequest(http.MethodPost,
		"http://myuser:mypass@localhost:8886/nonexisting/whep", bytes.NewReader([]byte(offer.SDP)))
	require.NoError(t, err)

	req.Header.Set("Content-Type", "application/sdp")

	res, err := hc.Do(req)
	require.NoError(t, err)
	defer res.Body.Close()

	require.Equal(t, http.StatusNotFound, res.StatusCode)
}

func TestServerPatchNotFound(t *testing.T) {
	s := initializeTestServer(t)
	defer s.Close()

	tr := &http.Transport{}
	defer tr.CloseIdleConnections()
	hc := &http.Client{Transport: tr}

	pc, err := pwebrtc.NewPeerConnection(pwebrtc.Configuration{})
	require.NoError(t, err)
	defer pc.GracefulClose() //nolint:errcheck

	_, err = pc.AddTransceiverFromKind(pwebrtc.RTPCodecTypeVideo)
	require.NoError(t, err)

	offer, err := pc.CreateOffer(nil)
	require.NoError(t, err)

	frag, err := whip.ICEFragmentMarshal(offer.SDP, []*pwebrtc.ICECandidateInit{{
		Candidate:     "mycandidate",
		SDPMLineIndex: ptrOf(uint16(0)),
	}})
	require.NoError(t, err)

	req, err := http.NewRequest(http.MethodPatch,
		"http://localhost:8886/nonexisting/whep/"+uuid.UUID{}.String(), bytes.NewReader(frag))
	require.NoError(t, err)

	req.Header.Set("Content-Type", "application/trickle-ice-sdpfrag")

	res, err := hc.Do(req)
	require.NoError(t, err)
	defer res.Body.Close()

	require.Equal(t, http.StatusNotFound, res.StatusCode)
}

func TestServerDeleteNotFound(t *testing.T) {
	s := initializeTestServer(t)
	defer s.Close()

	tr := &http.Transport{}
	defer tr.CloseIdleConnections()
	hc := &http.Client{Transport: tr}

	req, err := http.NewRequest(http.MethodDelete,
		"http://localhost:8886/nonexisting/whep/"+uuid.UUID{}.String(), nil)
	require.NoError(t, err)

	res, err := hc.Do(req)
	require.NoError(t, err)
	defer res.Body.Close()

	require.Equal(t, http.StatusNotFound, res.StatusCode)
}

func TestICEServerNoClientOnly(t *testing.T) {
	s := &Server{
		ICEServers: []conf.WebRTCICEServer{
			{
				URL:      "turn:turn.example.com:1234",
				Username: "user",
				Password: "passwrd",
			},
		},
	}
	clientICEServers, err := s.generateICEServers(true)
	require.NoError(t, err)
	require.Equal(t, len(s.ICEServers), len(clientICEServers))
	serverICEServers, err := s.generateICEServers(false)
	require.NoError(t, err)
	require.Equal(t, len(s.ICEServers), len(serverICEServers))
}

func TestICEServerClientOnly(t *testing.T) {
	s := &Server{
		ICEServers: []conf.WebRTCICEServer{
			{
				URL:        "turn:turn.example.com:1234",
				Username:   "user",
				Password:   "passwrd",
				ClientOnly: true,
			},
		},
	}
	clientICEServers, err := s.generateICEServers(true)
	require.NoError(t, err)
	require.Equal(t, len(s.ICEServers), len(clientICEServers))
	serverICEServers, err := s.generateICEServers(false)
	require.NoError(t, err)
	require.Empty(t, serverICEServers)
}