Zippytal-Node/webrtcGrpcMiddleware.go

package localserver

import (
	"context"
	"fmt"
	"strconv"

	"github.com/pion/webrtc/v3"
)

type GrpcRequestType string

const (
	PEER_CONNECTION_REQUEST GrpcRequestType = "peer_connection_request"
)

const (
	OFFER                                     ReqType = "offer"
	ANSWER                                    ReqType = "answer"
	COUNTER_OFFER                             ReqType = "webrtc_counter_offer"
	JOIN_HOSTED_SQUAD                         ReqType = "join_hosted_squad"
	HOSTED_SQUAD_ACCESS_DENIED                ReqType = "hosted_squad_access_denied"
	HOSTED_SQUAD_STOP_CALL                    ReqType = "hosted_squad_stop_call"
	HOSTED_SQUAD_ACCESS_GRANTED               ReqType = "hosted_squad_access_granted"
	LEAVE_HOSTED_SQUAD                        ReqType = "leave_hosted_squad"
	INCOMING_MEMBER_HOSTED                    ReqType = "incoming_member_hosted"
	LEAVING_MEMBER_HOSTED                     ReqType = "leaving_member_hosted"
	HOSTED_SQUAD_WEBRTC_OFFER                 ReqType = "hosted_squad_offer"
	HOSTED_SQUAD_WEBRTC_ANSWER                ReqType = "hosted_squad_answer"
	HOSTED_SQUAD_WEBRTC_RENNEGOTIATION_OFFER  ReqType = "hosted_squad_rennegotiation_offer"
	HOSTED_SQUAD_WEBRTC_RENNEGOTIATION_ANSWER ReqType = "hosted_squad_rennegotiation_answer"
	HOSTED_SQUAD_WEBRTC_COUNTER_OFFER         ReqType = "hosted_squad_webrtc_counter_offer"
	HOSTED_SQUAD_WEBRTC_CANDIDATE             ReqType = "hosted_squad_webrtc_candidate"
	HOSTED_SQUAD_REMOVE_VIDEO                 ReqType = "hosted_squad_remove_video"
	GET_HOSTED_SQUAD_TRACKS                   ReqType = "hosted_squad_get_tracks"
	NEW_HOSTED_SQUAD                                  = "new_hosted_squad"
)

type WebRTCGrpcMiddleware struct {
	Manager *WebRTCCallManager
	stream  GrpcManager_LinkClient
}

func NewWebRTCGrpcMiddleware(manager *WebRTCCallManager) (webrtcGrpcMiddleware *WebRTCGrpcMiddleware) {
	webrtcGrpcMiddleware = &WebRTCGrpcMiddleware{
		Manager: manager,
	}
	return
}

func validateRequest(req map[string]string, entries ...string) (err error) {
	for _, entry := range entries {
		if _, ok := req[entry]; !ok {
			err = fmt.Errorf("no field %s in req payload", entry)
			return
		}
	}
	return
}

func (wgm *WebRTCGrpcMiddleware) signalCandidate(to string, candidate *webrtc.ICECandidate) (err error) {
	err = wgm.stream.Send(&Request{
		Type:  string(HOSTED_SQUAD_WEBRTC_CANDIDATE),
		From:  wgm.Manager.ID,
		Token: "none",
		Payload: map[string]string{
			"from":          wgm.Manager.ID,
			"to":            to,
			"candidate":     candidate.ToJSON().Candidate,
			"sdpMid":        *candidate.ToJSON().SDPMid,
			"sdpMlineIndex": strconv.Itoa(int(*candidate.ToJSON().SDPMLineIndex)),
		},
	})
	return
}

func (wgm *WebRTCGrpcMiddleware) Process(ctx context.Context, req *Response, stream GrpcManager_LinkClient) (err error) {
	done, errCh := make(chan struct{}), make(chan error)
	go func() {
		defer func() {
			done <- struct{}{}
		}()
		switch req.Type {
		case NEW_HOSTED_SQUAD:
			if err := validateRequest(req.Payload, "ID"); err != nil {
				errCh <- err
				return
			}
			logger.Println("new squad incoming")
			wgm.Manager.SquadMapMux.Lock()
			wgm.Manager.Squads[req.Payload["ID"]] = &Squad{
				ID:      req.Payload["ID"],
				Members: []string{},
			}
			wgm.Manager.SquadMapMux.Unlock()
		case string(HOSTED_SQUAD_STOP_CALL):
			logger.Println("quit squad called")
			if err := validateRequest(req.Payload, FROM, "squadId"); err != nil {
				errCh <- err
				return
			}
			wgm.Manager.HandleLeavingMember(req.Payload[FROM], req.Payload["squadId"])
			done <- struct{}{}
		case string(PEER_CONNECTION_REQUEST):
			if err := validateRequest(req.Payload, FROM, TO); err != nil {
				errCh <- err
				return
			}
			logger.Println("creating offer for peer")
			if err := wgm.Manager.CreateOffer(ctx, req.Payload[FROM], req.Payload[TO], wgm.signalCandidate); err != nil {
				errCh <- err
				return
			}
		case string(HOSTED_SQUAD_WEBRTC_OFFER):
			if err := validateRequest(req.GetPayload(), FROM, TO, SDP, SQUAD_ID); err != nil {
				errCh <- err
				return
			}
			if err := wgm.Manager.HandleOffer(ctx, req.GetPayload(), wgm.signalCandidate); err != nil {
				errCh <- err
				return
			}
		case string(HOSTED_SQUAD_WEBRTC_ANSWER):
			if err := validateRequest(req.GetPayload(), FROM, TO, SDP); err != nil {
				errCh <- err
				return
			}
			if err := wgm.Manager.HandleAnswer(ctx, req.GetPayload()); err != nil {
				errCh <- err
				return
			}
		case string(HOSTED_SQUAD_WEBRTC_COUNTER_OFFER):
			if err := validateRequest(req.GetPayload(), FROM); err != nil {
				errCh <- err
				return
			}
			if err := wgm.Manager.HandleCounterOffer(ctx, req.Payload); err != nil {
				errCh <- err
				return
			}
		case string(HOSTED_SQUAD_WEBRTC_RENNEGOTIATION_ANSWER):
			logger.Println("received negotiation answer")
			if err := validateRequest(req.GetPayload(), FROM, SDP); err != nil {
				errCh <- err
				return
			}
			if err := wgm.Manager.HandleRennegotiationAnswer(req.Payload[FROM], req.Payload[SDP]); err != nil {
				errCh <- err
				return
			}
		case string(HOSTED_SQUAD_WEBRTC_RENNEGOTIATION_OFFER):
			logger.Println("received negotiation offer")
			if err := validateRequest(req.GetPayload(), FROM, SDP); err != nil {
				errCh <- err
				return
			}
			if err := wgm.Manager.HandleRennegotiationOffer(req.Payload[FROM], req.Payload[SDP]); err != nil {
				errCh <- err
				return
			}
		case string(HOSTED_SQUAD_WEBRTC_CANDIDATE):
			if err := validateRequest(req.GetPayload(), FROM, "candidate", "sdpMlineIndex", "sdpMid"); err != nil {
				errCh <- err
				return
			}
			logger.Println(req.Payload)
			i, err := strconv.Atoi(req.Payload["sdpMlineIndex"])
			if err != nil {
				errCh <- err
				return
			}
			sdpMlineIndex := uint16(i)
			sdpMid := req.Payload["sdpMid"]
			logger.Println(sdpMid, sdpMlineIndex)
			if err := wgm.Manager.AddCandidate(&webrtc.ICECandidateInit{
				Candidate:     req.Payload["candidate"],
				SDPMid:        &sdpMid,
				SDPMLineIndex: &sdpMlineIndex,
			}, req.Payload[FROM]); err != nil {
				errCh <- err
				return
			}
		default:
		}
	}()
	select {
	case <-ctx.Done():
		err = ctx.Err()
		return
	case <-done:
		return
	case err = <-errCh:
		return
	}
}