const clientsByUser = new Map();
export function addSseClient(userId, res) {
    const client = {
        userId,
        res,
        write: (payload) => {
            try {
                res.write(`data: ${JSON.stringify(payload)}\n\n`);
            }
            catch { }
        },
    };
    if (!clientsByUser.has(userId))
        clientsByUser.set(userId, new Set());
    clientsByUser.get(userId).add(client);
    // Initial hello
    client.write({ type: 'hello', at: Date.now() });
    // Heartbeat to keep connections alive through proxies
    const heartbeat = setInterval(() => {
        try {
            res.write(`: ping\n\n`);
        }
        catch { }
    }, 25000);
    // Return cleanup
    return () => {
        clearInterval(heartbeat);
        try {
            res.end();
        }
        catch { }
        clientsByUser.get(userId)?.delete(client);
        if (clientsByUser.get(userId)?.size === 0)
            clientsByUser.delete(userId);
    };
}
export function sendEvent(userId, event) {
    const set = clientsByUser.get(userId);
    if (!set || set.size === 0)
        return;
    for (const client of set)
        client.write(event);
}
export function sendToBoth(userA, userB, event) {
    sendEvent(userA, event);
    if (userB !== userA)
        sendEvent(userB, event);
}