package rtmp

import (
	"fmt"
	"io"
	"net"
	"os"
	"strings"
	"syscall"
	"time"
	"unsafe"

	"github.com/nareix/joy5/format/flv"
	"github.com/nareix/joy5/format/flv/flvio"
	log "github.com/sirupsen/logrus"

	"github.com/nareix/joy5/format/rtmp"
	"github.com/owncast/owncast/config"
	"github.com/owncast/owncast/models"
	"github.com/owncast/owncast/utils"
)

var (
	_hasInboundRTMPConnection = false
)

var _pipe *os.File
var _rtmpConnection net.Conn

var _setStreamAsConnected func()
var _setBroadcaster func(models.Broadcaster)

// Start starts the rtmp service, listening on specified RTMP port.
func Start(setStreamAsConnected func(), setBroadcaster func(models.Broadcaster)) {
	_setStreamAsConnected = setStreamAsConnected
	_setBroadcaster = setBroadcaster

	port := config.Config.GetRTMPServerPort()
	s := rtmp.NewServer()
	var lis net.Listener
	var err error
	if lis, err = net.Listen("tcp", fmt.Sprintf(":%d", port)); err != nil {
		log.Fatal(err)
	}

	s.LogEvent = func(c *rtmp.Conn, nc net.Conn, e int) {
		es := rtmp.EventString[e]
		log.Traceln(unsafe.Pointer(c), nc.LocalAddr(), nc.RemoteAddr(), es)
	}

	s.HandleConn = HandleConn

	if err != nil {
		log.Panicln(err)
	}
	log.Tracef("RTMP server is listening for incoming stream on port: %d", port)

	for {
		nc, err := lis.Accept()
		if err != nil {
			time.Sleep(time.Second)
			continue
		}
		go s.HandleNetConn(nc)
	}
}

func HandleConn(c *rtmp.Conn, nc net.Conn) {
	c.LogTagEvent = func(isRead bool, t flvio.Tag) {
		if t.Type == flvio.TAG_AMF0 {
			log.Tracef("%+v\n", t.DebugFields())
			setCurrentBroadcasterInfo(t, nc.RemoteAddr().String())
		}
	}

	if _hasInboundRTMPConnection {
		log.Errorln("stream already running; can not overtake an existing stream")
		nc.Close()
		return
	}

	streamingKeyComponents := strings.Split(c.URL.Path, "/")
	streamingKey := streamingKeyComponents[len(streamingKeyComponents)-1]
	if streamingKey != config.Config.VideoSettings.StreamingKey {
		log.Errorln("invalid streaming key; rejecting incoming stream")
		nc.Close()
		return
	}

	log.Infoln("Incoming RTMP connected.")
	_setStreamAsConnected()

	pipePath := utils.GetTemporaryPipePath()
	if !utils.DoesFileExists(pipePath) {
		err := syscall.Mkfifo(pipePath, 0666)
		if err != nil {
			log.Fatalln(err)
		}
	}

	_hasInboundRTMPConnection = true
	_rtmpConnection = nc

	f, err := os.OpenFile(pipePath, os.O_RDWR, os.ModeNamedPipe)
	_pipe = f
	if err != nil {
		panic(err)
	}

	w := flv.NewMuxer(f)

	for {
		if !_hasInboundRTMPConnection {
			break
		}

		// If we don't get a readable packet in 10 seconds give up and disconnect
		if err := _rtmpConnection.SetReadDeadline(time.Now().Add(10 * time.Second)); err != nil {
			log.Warnln(err)
		}
		pkt, err := c.ReadPacket()

		// Broadcaster disconnected
		if err == io.EOF {
			handleDisconnect(nc)
			break
		}

		// Read timeout.  Disconnect.
		if neterr, ok := err.(net.Error); ok && neterr.Timeout() {
			log.Debugln("Timeout reading the inbound stream from the broadcaster.  Assuming that they disconnected and ending the stream.")
			handleDisconnect(nc)
			break
		}

		if err := w.WritePacket(pkt); err != nil {
			panic(err)
		}
	}
}

func handleDisconnect(conn net.Conn) {
	if !_hasInboundRTMPConnection {
		return
	}

	log.Infoln("RTMP disconnected.")
	conn.Close()
	_pipe.Close()
	_hasInboundRTMPConnection = false
}

// Disconnect will force disconnect the current inbound RTMP connection.
func Disconnect() {
	if _rtmpConnection == nil {
		return
	}

	log.Traceln("Inbound stream disconnect requested.")
	handleDisconnect(_rtmpConnection)
}