/*!
 *
 * Copyright (c) 2024-2026 Diality Inc. - All Rights Reserved.
 * \copyright
 * THIS CODE MAY NOT BE COPIED OR REPRODUCED IN ANY FORM, IN PART OR IN
 * WHOLE, WITHOUT THE EXPLICIT PERMISSION OF THE COPYRIGHT OWNER.
 *
 * \file    RtServer.h
 * \author  (original)  Stephen Quong
 * \date    (original)  15-Jul-2026
 *
 */
#pragma once

#include <QByteArray>
#include <QLocalServer>
#include <QLocalSocket>
#include <QObject>
#include <QString>

#include "RtMessage.h"

/*!
 * \brief   Unix domain socket server for RtMessage frames.
 * \details Base class providing local-socket server support. Listens on a Unix
 *          domain socket, accepts one client at a time, parses inbound
 *          RtMessage frames, and emits didMessageReceive() for each complete
 *          frame. Outbound: call send() to reply to the connected client.
 *          Parser state is cleared automatically when the client disconnects.
 *
 *          Intended to be inherited by controllers (e.g. AgentSimController,
 *          CloudConnectController) that need to accept a connection and exchange
 *          framed messages over a local socket.
 */
class RtServer : public QObject
{
    Q_OBJECT

public:
    explicit RtServer(QObject *parent = nullptr);

    bool listen(const QString &socketPath);
    bool send(RtMessage::MsgId msgId, quint16 sequence, const QByteArray &payload = {});
    bool isConnected() const;

Q_SIGNALS:
    /*!
     * \brief   didMessageReceive
     * \details Emitted when a complete inbound RtMessage frame has been parsed.
     * \param   msgId    - message identifier from the frame header
     * \param   sequence - sequence number from the frame header
     * \param   payload  - decoded payload bytes, empty for zero-length frames
     */
    void didMessageReceive(RtMessage::MsgId msgId, quint16 sequence, QByteArray payload);

    /*!
     * \brief   didConnect
     * \details Emitted when a client connects.
     */
    void didConnect();

    /*!
     * \brief   didDisconnect
     * \details Emitted when the connected client disconnects.
     */
    void didDisconnect();

private Q_SLOTS:
    void onNewConnection();
    void onDisconnected();
    void onReadyRead();

private:
    QLocalServer _server;
    QLocalSocket *_client = nullptr;
    QByteArray _rxBuf;
    RtMessage _rxMsg;
};