package rtspv2

import (
	"bufio"
	"bytes"
	"crypto/md5"
	"crypto/tls"
	"encoding/base64"
	"encoding/binary"
	"errors"
	"fmt"
	"html"
	"io"
	"log"
	"net"
	"net/url"
	"strconv"
	"strings"
	"time"

	"github.com/deepch/vdk/av"
	"github.com/deepch/vdk/codec"
	"github.com/deepch/vdk/codec/aacparser"
	"github.com/deepch/vdk/codec/h264parser"
	"github.com/deepch/vdk/codec/h265parser"
	"github.com/deepch/vdk/format/rtsp/sdp"
)

const (
	SignalStreamRTPStop = iota
	SignalCodecUpdate
)

const (
	VIDEO = "video"
	AUDIO = "audio"
)

const (
	RTPHeaderSize      = 12
	RTCPSenderReport   = 200
	RTCPReceiverReport = 201
)

const (
	DESCRIBE = "DESCRIBE"
	OPTIONS  = "OPTIONS"
	PLAY     = "PLAY"
	PAUSE    = "PAUSE"
	SETUP    = "SETUP"
	TEARDOWN = "TEARDOWN"
)

type RTSPClient struct {
	control             string
	seq                 int
	session             string
	realm               string
	nonce               string
	username            string
	password            string
	startVideoTS        int64
	startAudioTS        int64
	videoID             int
	audioID             int
	videoIDX            int8
	audioIDX            int8
	mediaSDP            []sdp.Media
	SDPRaw              []byte
	conn                net.Conn
	connRW              *bufio.ReadWriter
	pURL                *url.URL
	headers             map[string]string
	Signals             chan int
	OutgoingProxyQueue  chan *[]byte
	OutgoingPacketQueue chan *av.Packet
	clientDigest        bool
	clientBasic         bool
	fuStarted           bool
	options             RTSPClientOptions
	BufferRtpPacket     *bytes.Buffer
	vps                 []byte
	sps                 []byte
	pps                 []byte
	CodecData           []av.CodecData
	AudioTimeLine       time.Duration
	AudioTimeScale      int64
	audioCodec          av.CodecType
	videoCodec          av.CodecType
	PreAudioTS          int64
	PreVideoTS          int64
	PreSequenceNumber   int
	FPS                 int
	WaitCodec           bool
	chTMP               int
	timestamp           int64
	sequenceNumber      int
	end                 int
	offset              int
	status              string
}

type RTSPClientOptions struct {
	Debug              bool
	URL                string
	DialTimeout        time.Duration
	ReadWriteTimeout   time.Duration
	DisableAudio       bool
	OutgoingProxy      bool
	InsecureSkipVerify bool
}

func Dial(options RTSPClientOptions) (*RTSPClient, error) {
	client := &RTSPClient{
		headers:             make(map[string]string),
		Signals:             make(chan int, 100),
		OutgoingProxyQueue:  make(chan *[]byte, 3000),
		OutgoingPacketQueue: make(chan *av.Packet, 3000),
		BufferRtpPacket:     bytes.NewBuffer([]byte{}),
		videoID:             -1,
		audioID:             -2,
		videoIDX:            -1,
		audioIDX:            -2,
		options:             options,
		AudioTimeScale:      8000,
	}
	client.headers["User-Agent"] = "Lavf58.76.100"
	err := client.parseURL(html.UnescapeString(client.options.URL))
	if err != nil {
		return nil, err
	}
	conn, err := net.DialTimeout("tcp", client.pURL.Host, client.options.DialTimeout)
	if err != nil {
		return nil, err
	}
	err = conn.SetDeadline(time.Now().Add(client.options.ReadWriteTimeout))
	if err != nil {
		return nil, err
	}
	if client.pURL.Scheme == "rtsps" {
		tlsConn := tls.Client(conn, &tls.Config{InsecureSkipVerify: options.InsecureSkipVerify, ServerName: client.pURL.Hostname()})
		err = tlsConn.Handshake()
		if err != nil {
			return nil, err
		}
		conn = tlsConn
	}
	client.conn = conn
	client.connRW = bufio.NewReadWriter(bufio.NewReader(conn), bufio.NewWriter(conn))
	err = client.request(OPTIONS, nil, client.pURL.String(), false, false)
	if err != nil {
		return nil, err
	}
	err = client.request(DESCRIBE, map[string]string{"Accept": "application/sdp"}, client.pURL.String(), false, false)
	if err != nil {
		return nil, err
	}
	for _, i2 := range client.mediaSDP {
		if (i2.AVType != VIDEO && i2.AVType != AUDIO) || (client.options.DisableAudio && i2.AVType == AUDIO) {
			//TODO check it
			if strings.Contains(string(client.SDPRaw), "LaunchDigital") {
				client.chTMP += 2
			}
			continue
		}
		err = client.request(SETUP, map[string]string{"Transport": "RTP/AVP/TCP;unicast;interleaved=" + strconv.Itoa(client.chTMP) + "-" + strconv.Itoa(client.chTMP+1)}, client.ControlTrack(i2.Control), false, false)
		if err != nil {
			return nil, err
		}
		if i2.AVType == VIDEO {
			if i2.Type == av.H264 {
				if len(i2.SpropParameterSets) > 1 {
					if codecData, err := h264parser.NewCodecDataFromSPSAndPPS(i2.SpropParameterSets[0], i2.SpropParameterSets[1]); err == nil {
						client.sps = i2.SpropParameterSets[0]
						client.pps = i2.SpropParameterSets[1]
						client.CodecData = append(client.CodecData, codecData)
					}
				} else {
					client.CodecData = append(client.CodecData, h264parser.CodecData{})
					client.WaitCodec = true
				}
				client.FPS = i2.FPS
				client.videoCodec = av.H264
			} else if i2.Type == av.H265 {
				if len(i2.SpropVPS) > 1 && len(i2.SpropSPS) > 1 && len(i2.SpropPPS) > 1 {
					if codecData, err := h265parser.NewCodecDataFromVPSAndSPSAndPPS(i2.SpropVPS, i2.SpropSPS, i2.SpropPPS); err == nil {
						client.vps = i2.SpropVPS
						client.sps = i2.SpropSPS
						client.pps = i2.SpropPPS
						client.CodecData = append(client.CodecData, codecData)
					}
				} else {
					client.CodecData = append(client.CodecData, h265parser.CodecData{})
				}
				client.videoCodec = av.H265

			} else {
				client.Println("SDP Video Codec Type Not Supported", i2.Type)
			}
			client.videoIDX = int8(len(client.CodecData) - 1)
			client.videoID = client.chTMP
		}
		if i2.AVType == AUDIO {
			client.audioID = client.chTMP
			var CodecData av.AudioCodecData
			switch i2.Type {
			case av.AAC:
				CodecData, err = aacparser.NewCodecDataFromMPEG4AudioConfigBytes(i2.Config)
				if err == nil {
					client.Println("Audio AAC bad config")
				}
			case av.OPUS:
				var cl av.ChannelLayout
				switch i2.ChannelCount {
				case 1:
					cl = av.CH_MONO
				case 2:
					cl = av.CH_STEREO
				default:
					cl = av.CH_MONO
				}
				CodecData = codec.NewOpusCodecData(i2.TimeScale, cl)
			case av.PCM_MULAW:
				CodecData = codec.NewPCMMulawCodecData()
			case av.PCM_ALAW:
				CodecData = codec.NewPCMAlawCodecData()
			case av.PCM:
				CodecData = codec.NewPCMCodecData()
			default:
				client.Println("Audio Codec", i2.Type, "not supported")
			}
			if CodecData != nil {
				client.CodecData = append(client.CodecData, CodecData)
				client.audioIDX = int8(len(client.CodecData) - 1)
				client.audioCodec = CodecData.Type()
				if i2.TimeScale != 0 {
					client.AudioTimeScale = int64(i2.TimeScale)
				}
			}
		}
		client.chTMP += 2
	}
	customHeaders := map[string]string{"Range": "npt=0.00-"}
	err = client.request(PLAY, customHeaders, client.control, false, false)
	if err != nil {
		return nil, err
	}
	go client.startStream()
	return client, nil
}

func (client *RTSPClient) ControlTrack(track string) string {
	if strings.Contains(track, "rtsp://") {
		return track
	}
	if !strings.HasSuffix(client.control, "/") {
		track = "/" + track
	}
	return client.control + track
}

func (client *RTSPClient) startStream() {
	defer func() {
		client.Signals <- SignalStreamRTPStop
	}()
	timer := time.Now()
	oneb := make([]byte, 1)
	header := make([]byte, 4)
	var fixed bool
	for {
		err := client.conn.SetDeadline(time.Now().Add(client.options.ReadWriteTimeout))
		if err != nil {
			client.Println("RTSP Client RTP SetDeadline", err)
			return
		}
		if int(time.Since(timer).Seconds()) > 25 {
			err := client.request(OPTIONS, map[string]string{"Require": "implicit-play"}, client.control, false, true)
			if err != nil {
				client.Println("RTSP Client RTP keep-alive", err)
				return
			}
			timer = time.Now()
		}
		if client.status == PAUSE {
			// client.Println("RTSP Client PAUSE")
			continue
		}
		if !fixed {
			nb, err := io.ReadFull(client.connRW, header)
			if err != nil || nb != 4 {
				client.Println("RTSP Client RTP Read Header", err)
				return
			}
		}
		fixed = false
		switch header[0] {
		case 0x24:
			length := int32(binary.BigEndian.Uint16(header[2:]))
			if length > 65535 || length < 12 {
				client.Println("RTSP Client RTP Incorrect Packet Size")
				return
			}
			content := make([]byte, length+4)
			content[0] = header[0]
			content[1] = header[1]
			content[2] = header[2]
			content[3] = header[3]
			n, rerr := io.ReadFull(client.connRW, content[4:length+4])
			if rerr != nil || n != int(length) {
				client.Println("RTSP Client RTP ReadFull", err)
				return
			}

			//atomic.AddInt64(&client.Bitrate, int64(length+4))
			if client.options.OutgoingProxy {
				if len(client.OutgoingProxyQueue) < 2000 {
					client.OutgoingProxyQueue <- &content
				} else {
					client.Println("RTSP Client OutgoingProxy Chanel Full")
					return
				}
			}
			pkt, got := client.RTPDemuxer(&content)
			if !got {
				continue
			}

			for _, i2 := range pkt {
				if len(client.OutgoingPacketQueue) > 2000 {
					client.Println("RTSP Client OutgoingPacket Chanel Full")
					return
				}
				client.OutgoingPacketQueue <- i2
			}
		case 0x52:
			var responseTmp []byte
			for {
				n, rerr := io.ReadFull(client.connRW, oneb)
				if rerr != nil || n != 1 {
					client.Println("RTSP Client RTP Read Keep-Alive Header", rerr)
					return
				}
				responseTmp = append(responseTmp, oneb...)
				if (len(responseTmp) > 4 && bytes.Equal(responseTmp[len(responseTmp)-4:], []byte("\r\n\r\n"))) || len(responseTmp) > 768 {
					if strings.Contains(string(responseTmp), "Content-Length:") {
						si, err := strconv.Atoi(stringInBetween(string(responseTmp), "Content-Length: ", "\r\n"))
						if err != nil {
							client.Println("RTSP Client RTP Read Keep-Alive Content-Length", err)
							return
						}
						cont := make([]byte, si)
						_, err = io.ReadFull(client.connRW, cont)
						if err != nil {
							client.Println("RTSP Client RTP Read Keep-Alive ReadFull", err)
							return
						}
					}
					break
				}
			}
		default:
			client.Println("RTSP Client RTP Read DeSync")
			return
		}
	}
}

func (client *RTSPClient) request(method string, customHeaders map[string]string, uri string, one bool, nores bool) (err error) {
	err = client.conn.SetDeadline(time.Now().Add(client.options.ReadWriteTimeout))
	if err != nil {
		return
	}
	client.seq++
	builder := bytes.Buffer{}
	builder.WriteString(fmt.Sprintf("%s %s RTSP/1.0\r\n", method, uri))
	builder.WriteString(fmt.Sprintf("CSeq: %d\r\n", client.seq))
	if client.clientDigest {
		builder.WriteString(fmt.Sprintf("Authorization: %s\r\n", client.createDigest(method, uri)))
	}
	for k, v := range customHeaders {
		builder.WriteString(fmt.Sprintf("%s: %s\r\n", k, v))
	}
	for k, v := range client.headers {
		builder.WriteString(fmt.Sprintf("%s: %s\r\n", k, v))
	}
	builder.WriteString("\r\n")
	client.Println(builder.String())
	s := builder.String()
	_, err = client.connRW.WriteString(s)
	if err != nil {
		return
	}
	err = client.connRW.Flush()
	if err != nil {
		return
	}
	builder.Reset()
	if !nores {
		var isPrefix bool
		var line []byte
		var contentLen int
		res := make(map[string]string)
		for {
			line, isPrefix, err = client.connRW.ReadLine()
			if err != nil {
				return
			}
			if strings.Contains(string(line), "RTSP/1.0") && (!strings.Contains(string(line), "200") && !strings.Contains(string(line), "401")) {
				time.Sleep(1 * time.Second)
				err = errors.New("Camera send status" + string(line))
				return
			}
			builder.Write(line)
			if !isPrefix {
				builder.WriteString("\r\n")
			}
			if len(line) == 0 {
				break
			}
			splits := strings.SplitN(string(line), ":", 2)
			if len(splits) == 2 {
				if splits[0] == "Content-length" {
					splits[0] = "Content-Length"
				}
				res[splits[0]] = splits[1]
			}
		}
		if val, ok := res["WWW-Authenticate"]; ok {
			if strings.Contains(val, "Digest") {
				client.realm = stringInBetween(val, "realm=\"", "\"")
				client.nonce = stringInBetween(val, "nonce=\"", "\"")
				client.clientDigest = true
			} else if strings.Contains(val, "Basic") {
				client.headers["Authorization"] = "Basic " + base64.StdEncoding.EncodeToString([]byte(client.username+":"+client.password))
				client.clientBasic = true
			}
			if !one {
				err = client.request(method, customHeaders, uri, true, false)
				return
			}
			err = errors.New("RTSP Client Unauthorized 401")
			return
		}
		if val, ok := res["Session"]; ok {
			splits2 := strings.Split(val, ";")
			client.session = strings.TrimSpace(splits2[0])
			client.headers["Session"] = strings.TrimSpace(splits2[0])
		}
		if val, ok := res["Content-Base"]; ok {
			client.control = strings.TrimSpace(val)
		}
		if val, ok := res["RTP-Info"]; ok {
			splits := strings.Split(val, ",")
			for _, v := range splits {
				splits2 := strings.Split(v, ";")
				for _, vs := range splits2 {
					if strings.Contains(vs, "rtptime") {
						splits3 := strings.Split(vs, "=")
						if len(splits3) == 2 {
							if client.startVideoTS == 0 {
								ts, _ := strconv.Atoi(strings.TrimSpace(splits3[1]))
								client.startVideoTS = int64(ts)
							} else {
								ts, _ := strconv.Atoi(strings.TrimSpace(splits3[1]))
								client.startAudioTS = int64(ts)
							}
						}
					}
				}
			}
		}
		if method == DESCRIBE {
			if val, ok := res["Content-Length"]; ok {
				contentLen, err = strconv.Atoi(strings.TrimSpace(val))
				if err != nil {
					return
				}
				client.SDPRaw = make([]byte, contentLen)
				_, err = io.ReadFull(client.connRW, client.SDPRaw)
				if err != nil {
					return
				}
				builder.Write(client.SDPRaw)
				_, client.mediaSDP = sdp.Parse(string(client.SDPRaw))
			}
		}
		if method == SETUP {
			//deep := stringInBetween(builder.String(), "interleaved=", ";")
			if val, ok := res["Transport"]; ok {
				splits2 := strings.Split(val, ";")
				for _, vs := range splits2 {
					if strings.Contains(vs, "interleaved") {
						splits3 := strings.Split(vs, "=")
						if len(splits3) == 2 {
							splits4 := strings.Split(splits3[1], "-")
							if len(splits4) == 2 {
								if val, err := strconv.Atoi(splits4[0]); err == nil {
									client.chTMP = val
								}
							}
						}
					}
				}
			}

		}
		client.Println(builder.String())
	}
	return
}

func (client *RTSPClient) Pause() error {
	client.status = PAUSE
	return client.request(PAUSE, nil, client.pURL.String(), false, true)
}

func (client *RTSPClient) Play(customHeaders map[string]string) error {
	client.status = PLAY
	return client.request(PLAY, customHeaders, client.pURL.String(), false, true)
}

func (client *RTSPClient) Close() {
	if client.conn != nil {
		client.conn.SetDeadline(time.Now().Add(time.Second))
		client.request(TEARDOWN, nil, client.control, false, true)
		err := client.conn.Close()
		client.Println("RTSP Client Close", err)
	}
}

func (client *RTSPClient) parseURL(rawURL string) error {
	l, err := url.Parse(rawURL)
	if err != nil {
		return err
	}
	username := l.User.Username()
	password, _ := l.User.Password()
	l.User = nil
	if l.Port() == "" {
		l.Host = fmt.Sprintf("%s:%s", l.Host, "554")
	}
	if l.Scheme != "rtsp" && l.Scheme != "rtsps" {
		l.Scheme = "rtsp"
	}
	client.pURL = l
	client.username = username
	client.password = password
	client.control = l.String()
	return nil
}

func (client *RTSPClient) createDigest(method string, uri string) string {
	md5UserRealmPwd := fmt.Sprintf("%x", md5.Sum([]byte(fmt.Sprintf("%s:%s:%s", client.username, client.realm, client.password))))
	md5MethodURL := fmt.Sprintf("%x", md5.Sum([]byte(fmt.Sprintf("%s:%s", method, uri))))
	response := fmt.Sprintf("%x", md5.Sum([]byte(fmt.Sprintf("%s:%s:%s", md5UserRealmPwd, client.nonce, md5MethodURL))))
	Authorization := fmt.Sprintf("Digest username=\"%s\", realm=\"%s\", nonce=\"%s\", uri=\"%s\", response=\"%s\"", client.username, client.realm, client.nonce, uri, response)
	return Authorization
}

func stringInBetween(str string, start string, end string) (result string) {
	s := strings.Index(str, start)
	if s == -1 {
		return
	}
	str = str[s+len(start):]
	e := strings.Index(str, end)
	if e == -1 {
		return
	}
	str = str[:e]
	return str
}

func (client *RTSPClient) CodecUpdateSPS(val []byte) {
	if client.videoCodec != av.H264 && client.videoCodec != av.H265 {
		return
	}
	if bytes.Equal(val, client.sps) {
		return
	}
	client.sps = val
	if (client.videoCodec == av.H264 && len(client.pps) == 0) || (client.videoCodec == av.H265 && (len(client.vps) == 0 || len(client.pps) == 0)) {
		return
	}
	var codecData av.VideoCodecData
	var err error
	switch client.videoCodec {
	case av.H264:
		client.Println("Codec Update SPS", val)
		codecData, err = h264parser.NewCodecDataFromSPSAndPPS(val, client.pps)
		if err != nil {
			client.Println("Parse Codec Data Error", err)
			return
		}
	case av.H265:
		codecData, err = h265parser.NewCodecDataFromVPSAndSPSAndPPS(client.vps, val, client.pps)
		if err != nil {
			client.Println("Parse Codec Data Error", err)
			return
		}
	}
	if len(client.CodecData) > 0 {
		for i, i2 := range client.CodecData {
			if i2.Type().IsVideo() {
				client.CodecData[i] = codecData
			}
		}
	} else {
		client.CodecData = append(client.CodecData, codecData)
	}
	client.Signals <- SignalCodecUpdate
}

func (client *RTSPClient) CodecUpdatePPS(val []byte) {
	if client.videoCodec != av.H264 && client.videoCodec != av.H265 {
		return
	}
	if bytes.Equal(val, client.pps) {
		return
	}
	client.pps = val
	if (client.videoCodec == av.H264 && len(client.sps) == 0) || (client.videoCodec == av.H265 && (len(client.vps) == 0 || len(client.sps) == 0)) {
		return
	}
	var codecData av.VideoCodecData
	var err error
	switch client.videoCodec {
	case av.H264:
		client.Println("Codec Update PPS", val)
		codecData, err = h264parser.NewCodecDataFromSPSAndPPS(client.sps, val)
		if err != nil {
			client.Println("Parse Codec Data Error", err)
			return
		}
	case av.H265:
		codecData, err = h265parser.NewCodecDataFromVPSAndSPSAndPPS(client.vps, client.sps, val)
		if err != nil {
			client.Println("Parse Codec Data Error", err)
			return
		}
	}
	if len(client.CodecData) > 0 {
		for i, i2 := range client.CodecData {
			if i2.Type().IsVideo() {
				client.CodecData[i] = codecData
			}
		}
	} else {
		client.CodecData = append(client.CodecData, codecData)
	}
	client.Signals <- SignalCodecUpdate
}

func (client *RTSPClient) CodecUpdateVPS(val []byte) {
	if client.videoCodec != av.H265 {
		return
	}
	if bytes.Equal(val, client.vps) {
		return
	}
	client.vps = val
	if len(client.sps) == 0 || len(client.pps) == 0 {
		return
	}
	codecData, err := h265parser.NewCodecDataFromVPSAndSPSAndPPS(val, client.sps, client.pps)
	if err != nil {
		client.Println("Parse Codec Data Error", err)
		return
	}
	if len(client.CodecData) > 0 {
		for i, i2 := range client.CodecData {
			if i2.Type().IsVideo() {
				client.CodecData[i] = codecData
			}
		}
	} else {
		client.CodecData = append(client.CodecData, codecData)
	}

	client.Signals <- SignalCodecUpdate

}

// Println mini logging functions
func (client *RTSPClient) Println(v ...interface{}) {
	if client.options.Debug {
		log.Println(v)
	}
}

// binSize
func binSize(val int) []byte {
	buf := make([]byte, 4)
	binary.BigEndian.PutUint32(buf, uint32(val))
	return buf
}

func isRTCPPacket(content []byte) bool {
	rtcpPacketType := content[5]
	return rtcpPacketType == RTCPSenderReport || rtcpPacketType == RTCPReceiverReport
}