package main

import (
	"log"

	"github.com/bluenviron/gortsplib/v4"
	"github.com/bluenviron/gortsplib/v4/pkg/base"
	"github.com/bluenviron/gortsplib/v4/pkg/description"
	"github.com/bluenviron/gortsplib/v4/pkg/format"
	"github.com/pion/rtp"
)

// This example shows how to
// 1. connect to a RTSP server
// 2. read all media streams on a path
// 3. Get the PTS and NTP timestamp of incoming RTP packets

func main() {
	c := gortsplib.Client{}

	// parse URL
	u, err := base.ParseURL("rtsp://localhost:8554/mystream")
	if err != nil {
		panic(err)
	}

	// connect to the server
	err = c.Start(u.Scheme, u.Host)
	if err != nil {
		panic(err)
	}
	defer c.Close()

	// find available medias
	desc, _, err := c.Describe(u)
	if err != nil {
		panic(err)
	}

	// setup all medias
	err = c.SetupAll(desc.BaseURL, desc.Medias)
	if err != nil {
		panic(err)
	}

	// called when a RTP packet arrives
	c.OnPacketRTPAny(func(medi *description.Media, forma format.Format, pkt *rtp.Packet) {
		// get the PTS timestamp of the packet, i.e. timestamp relative to the start of the session
		pts, ptsAvailable := c.PacketPTS(medi, pkt)
		log.Printf("PTS: available=%v, value=%v\n", ptsAvailable, pts)

		// get the NTP timestamp of the packet, i.e. the absolute timestamp
		ntp, ntpAvailable := c.PacketNTP(medi, pkt)
		log.Printf("NTP: available=%v, value=%v\n", ntpAvailable, ntp)
	})

	// start playing
	_, err = c.Play(nil)
	if err != nil {
		panic(err)
	}

	// wait until a fatal error
	panic(c.Wait())
}