// Package rtmp contains the RTMP static source.
package rtmp

import (
	"context"
	ctls "crypto/tls"
	"fmt"
	"net"
	"net/url"
	"time"

	"github.com/bluenviron/gortsplib/v4/pkg/description"

	"github.com/bluenviron/mediamtx/internal/conf"
	"github.com/bluenviron/mediamtx/internal/defs"
	"github.com/bluenviron/mediamtx/internal/logger"
	"github.com/bluenviron/mediamtx/internal/protocols/rtmp"
	"github.com/bluenviron/mediamtx/internal/protocols/tls"
	"github.com/bluenviron/mediamtx/internal/stream"
)

// Source is a RTMP static source.
type Source struct {
	ReadTimeout  conf.StringDuration
	WriteTimeout conf.StringDuration
	Parent       defs.StaticSourceParent
}

// Log implements logger.Writer.
func (s *Source) Log(level logger.Level, format string, args ...interface{}) {
	s.Parent.Log(level, "[RTMP source] "+format, args...)
}

// Run implements StaticSource.
func (s *Source) Run(params defs.StaticSourceRunParams) error {
	s.Log(logger.Debug, "connecting")

	u, err := url.Parse(params.ResolvedSource)
	if err != nil {
		return err
	}

	// add default port
	_, _, err = net.SplitHostPort(u.Host)
	if err != nil {
		if u.Scheme == "rtmp" {
			u.Host = net.JoinHostPort(u.Host, "1935")
		} else {
			u.Host = net.JoinHostPort(u.Host, "1936")
		}
	}

	nconn, err := func() (net.Conn, error) {
		ctx2, cancel2 := context.WithTimeout(params.Context, time.Duration(s.ReadTimeout))
		defer cancel2()

		if u.Scheme == "rtmp" {
			return (&net.Dialer{}).DialContext(ctx2, "tcp", u.Host)
		}

		return (&ctls.Dialer{
			Config: tls.ConfigForFingerprint(params.Conf.SourceFingerprint),
		}).DialContext(ctx2, "tcp", u.Host)
	}()
	if err != nil {
		return err
	}

	readDone := make(chan error)
	go func() {
		readDone <- s.runReader(u, nconn)
	}()

	for {
		select {
		case err := <-readDone:
			nconn.Close()
			return err

		case <-params.ReloadConf:

		case <-params.Context.Done():
			nconn.Close()
			<-readDone
			return nil
		}
	}
}

func (s *Source) runReader(u *url.URL, nconn net.Conn) error {
	nconn.SetReadDeadline(time.Now().Add(time.Duration(s.ReadTimeout)))
	nconn.SetWriteDeadline(time.Now().Add(time.Duration(s.WriteTimeout)))
	conn, err := rtmp.NewClientConn(nconn, u, false)
	if err != nil {
		return err
	}

	r, err := rtmp.NewReader(conn)
	if err != nil {
		return err
	}

	var stream *stream.Stream

	medias, err := rtmp.ToStream(r, &stream)
	if err != nil {
		return err
	}

	if len(medias) == 0 {
		return fmt.Errorf("no supported tracks found")
	}

	res := s.Parent.SetReady(defs.PathSourceStaticSetReadyReq{
		Desc:               &description.Session{Medias: medias},
		GenerateRTPPackets: true,
	})
	if res.Err != nil {
		return res.Err
	}

	defer s.Parent.SetNotReady(defs.PathSourceStaticSetNotReadyReq{})

	stream = res.Stream

	// disable write deadline to allow outgoing acknowledges
	nconn.SetWriteDeadline(time.Time{})

	for {
		nconn.SetReadDeadline(time.Now().Add(time.Duration(s.ReadTimeout)))
		err := r.Read()
		if err != nil {
			return err
		}
	}
}

// APISourceDescribe implements StaticSource.
func (*Source) APISourceDescribe() defs.APIPathSourceOrReader {
	return defs.APIPathSourceOrReader{
		Type: "rtmpSource",
		ID:   "",
	}
}