export function connectWs(onMessage, opts = {}) {
    let ws, retry = 0, closed = false;
    function open() {
        const proto = location.protocol === 'https:' ? 'wss' : 'ws';
        const params = new URLSearchParams();
        if (opts.room) params.set('room', opts.room);
        if (opts.kind) params.set('kind', opts.kind);
        const qs = params.toString();
        ws = new WebSocket(`${proto}://${location.host}/ws${qs ? '?' + qs : ''}`);
        ws.addEventListener('open', () => { retry = 0; opts.onOpen?.(); });
        ws.addEventListener('message', (ev) => {
            try { onMessage(JSON.parse(ev.data)); } catch { }
        });
        ws.addEventListener('close', () => {
            opts.onClose?.();
            if (closed) return;
            retry = Math.min(retry + 1, 6);
            setTimeout(open, 500 * 2 ** retry);
        });
        ws.addEventListener('error', () => ws.close());
    }
    open();
    return {
        // Returns true when the message was actually queued on a live socket,
        // false when the socket is closing/reconnecting. Callers that need to
        // surface a transport failure (transport buttons) inspect the result;
        // fire-and-forget callers can ignore it.
        send(msg) {
            if (ws?.readyState !== WebSocket.OPEN) return false;
            ws.send(JSON.stringify(msg));
            return true;
        },
        close() { closed = true; ws?.close(); },
        get readyState() { return ws?.readyState; }
    };
}