swaf/src/auth/magic_link/MagicLinkWebSocketListener.ts

import {Session} from "express-session";
import {IncomingMessage} from "http";
import WebSocket from "ws";

import Application from "../../Application.js";
import SessionWebSocketListener from "../../SessionWebSocketListener.js";
import MagicLink from "../models/MagicLink.js";

export default class MagicLinkWebSocketListener<A extends Application> extends SessionWebSocketListener<A> {
    private readonly connections: { [p: string]: (() => void)[] | undefined } = {};

    public refreshMagicLink(sessionId: string): void {
        const fs = this.connections[sessionId];
        if (fs) {
            fs.forEach(f => f());
        }
    }

    public async handleSessionSocket(socket: WebSocket, request: IncomingMessage, session: Session): Promise<void> {
        // Refuse any incoming data
        socket.on('message', () => {
            socket.close(1003);
        });

        // Get magic link
        const magicLink = await MagicLink.select()
            .where('session_id', session.id)
            .sortBy('authorized')
            .first();

        // Refresh if immediately applicable
        if (!magicLink || !await magicLink.isValid() || await magicLink.isAuthorized()) {
            socket.send('refresh');
            const reason = magicLink ?
                'Magic link state changed.' :
                'Magic link not found for session ' + session.id;
            socket.close(1000, reason);
            return;
        }

        const validityTimeout = setTimeout(() => {
            socket.send('refresh');
            socket.close(1000, 'Timed out');
        }, magicLink.getExpirationDate().getTime() - new Date().getTime());

        const f = () => {
            clearTimeout(validityTimeout);
            socket.send('refresh');
            socket.close(1000, 'Closed by server');
        };

        socket.on('close', () => {
            const connections = this.connections[session.id];
            if (connections) {
                this.connections[session.id] = connections.filter(f => f !== f);
                if (connections.length === 0) delete this.connections[session.id];
            }
        });

        let connections = this.connections[session.id];
        if (!connections) connections = this.connections[session.id] = [];
        connections.push(f);
    }

    public path(): string {
        return '/magic-link';
    }
}