Files
PrivyDrop/frontend/lib/webrtc_Recipient.ts
T
2025-09-08 00:12:02 +08:00

112 lines
3.5 KiB
TypeScript

// Recipient flow: Join room; receive 'offer' event -> createPeerConnection + createDataChannel -> send answer
import BaseWebRTC, { WebRTCConfig } from "./webrtc_base";
interface AnswerPayload {
answer: RTCSessionDescriptionInit;
peerId: string;
}
export default class WebRTC_Recipient extends BaseWebRTC {
constructor(config: WebRTCConfig) {
super(config);
this.setupRecipientSocketListeners();
}
private setupRecipientSocketListeners(): void {
this.socket.on("offer", ({ peerId, offer, from }) => {
this.handleOffer({ peerId, offer, from });
});
this.socket.on("answer", ({ answer, peerId }) => {
this.handleAnswer({ answer, peerId });
});
// Add listener for initiator re-online
this.socket.on("initiator-online", ({ roomId }) => {
this.log("log", `Received initiator-online for room: ${roomId}`);
// Send a ready response
this.log(
"log",
`Sending recipient-ready, my peerId: ${this.socket.id}`,
this.peerId
);
// Send a ready response
this.socket.emit("recipient-ready", {
roomId: this.roomId,
peerId: this.socket.id,
});
});
}
// Recipient creates a connection upon receiving an offer
private async handleOffer({
peerId,
offer,
from,
}: {
offer: RTCSessionDescriptionInit;
peerId: string;
from: string;
}): Promise<void> {
this.log("log", `Handling offer from peer ${from}`);
try {
// 1. Clean up existing connections
await this.cleanupExistingConnection(from);
// 2. Create a new connection
const peerConnection = await this.createPeerConnection(from);
// Then create a data channel
await this.createDataChannel(from);
// 4. Set the remote description
// console.log(`Setting remote description for peer ${from}`);
await peerConnection.setRemoteDescription(
new RTCSessionDescription(offer)
);
// Create and set the local description (answer)
// console.log(`Creating answer for peer ${from}`);
const answer = await peerConnection.createAnswer();
await peerConnection.setLocalDescription(answer);
// Send the answer
this.log("log", `Sending answer to peer ${from}`);
this.socket.emit("answer", {
answer,
peerId: from,
from: this.socket.id,
});
// Finally, process the cached ICE candidates
await this.addQueuedIceCandidates(from);
} catch (error) {
this.fireError("Error handling offer", { error, from });
// Clean up the failed connection
await this.cleanupExistingConnection(from);
}
}
private async handleAnswer({ answer, peerId }: AnswerPayload): Promise<void> {
const peerConnection = this.peerConnections.get(peerId);
if (!peerConnection) {
this.fireError("No peer connection for handleAnswer", { peerId });
return;
}
try {
await peerConnection.setRemoteDescription(
new RTCSessionDescription(answer)
);
} catch (error) {
this.fireError("Error handling answer", { error, peerId });
}
}
protected async createDataChannel(peerId: string): Promise<void> {
const peerConnection = this.peerConnections.get(peerId);
if (!peerConnection) {
this.fireError(`No peer connection found for peer ${peerId}`, { peerId });
return;
}
peerConnection.ondatachannel = (event) => {
this.setupDataChannel(event.channel, peerId);
this.dataChannels.set(peerId, event.channel);
};
}
}