package webrtc

import (
	"github.com/AlexxIT/go2rtc/pkg/streamer"
	"github.com/pion/sdp/v3"
	"github.com/pion/webrtc/v3"
)

func (c *Conn) CreateOffer() (string, error) {
	init := webrtc.RTPTransceiverInit{Direction: webrtc.RTPTransceiverDirectionRecvonly}
	_, _ = c.pc.AddTransceiverFromKind(webrtc.RTPCodecTypeVideo, init)
	_, _ = c.pc.AddTransceiverFromKind(webrtc.RTPCodecTypeAudio, init)

	desc, err := c.pc.CreateOffer(nil)
	if err != nil {
		return "", err
	}

	if err = c.pc.SetLocalDescription(desc); err != nil {
		return "", err
	}

	return desc.SDP, nil
}

func (c *Conn) CreateCompleteOffer() (string, error) {
	if _, err := c.CreateOffer(); err != nil {
		return "", err
	}

	<-webrtc.GatheringCompletePromise(c.pc)
	return c.pc.LocalDescription().SDP, nil
}

func (c *Conn) SetAnswer(answer string) (err error) {
	desc := webrtc.SessionDescription{SDP: answer, Type: webrtc.SDPTypeAnswer}
	if err = c.pc.SetRemoteDescription(desc); err != nil {
		return
	}

	sd := &sdp.SessionDescription{}
	if err = sd.Unmarshal([]byte(answer)); err != nil {
		return
	}

	medias := streamer.UnmarshalMedias(sd.MediaDescriptions)

	// sort medias, so video will always be before audio
	// and ignore application media from Hass default lovelace card
	for _, media := range medias {
		if media.Kind == streamer.KindVideo {
			c.medias = append(c.medias, media)
		}
	}
	for _, media := range medias {
		if media.Kind == streamer.KindAudio {
			c.medias = append(c.medias, media)
		}
	}

	return nil
}