carplaymanager.cpp

#include "carplaymanager.h"
#include <QDebug>
#include <QFile>
#include <QDir>
#include <QProcess>
#include <QJsonDocument>
#include <QJsonObject>

// USB Vendor/Product IDs for Apple devices
static const uint16_t APPLE_VENDOR_ID = 0x05AC;
static const uint16_t IPHONE_PRODUCT_ID_MIN = 0x12A0;
static const uint16_t IPHONE_PRODUCT_ID_MAX = 0x12AF;

// CarPlay default video resolution (matches iPhone CarPlay output)
static const int DEFAULT_VIDEO_WIDTH = 800;
static const int DEFAULT_VIDEO_HEIGHT = 480;
static const int DEFAULT_FRAME_RATE = 30;

// Polling intervals
static const int USB_POLL_INTERVAL_MS = 2000;
static const int CONNECTION_TIMEOUT_MS = 10000;

CarPlayManager::CarPlayManager(QObject *parent)
    : QObject(parent)
    , m_connected(false)
    , m_streaming(false)
    , m_connectionState(Disconnected)
    , m_videoWidth(DEFAULT_VIDEO_WIDTH)
    , m_videoHeight(DEFAULT_VIDEO_HEIGHT)
    , m_frameRate(DEFAULT_FRAME_RATE)
    , m_audioEnabled(true)
    , m_audioVolume(80)
    , m_microphoneEnabled(true)
    , m_nightMode(false)
    , m_wirelessMode(false)
    , m_videoThread(nullptr)
    , m_audioThread(nullptr)
    , m_carplayHandle(nullptr)
    , m_usbHandle(nullptr)
{
    // Set up USB polling timer
    m_usbPollTimer.setInterval(USB_POLL_INTERVAL_MS);
    connect(&m_usbPollTimer, &QTimer::timeout, this, &CarPlayManager::onUsbPollTimeout);

    // Set up connection timeout timer
    m_connectionTimer.setSingleShot(true);
    m_connectionTimer.setInterval(CONNECTION_TIMEOUT_MS);
    connect(&m_connectionTimer, &QTimer::timeout, this, &CarPlayManager::onConnectionTimeout);

    // Initialize USB subsystem
    initializeUsb();

    updateConnectionStatus("Ready - Connect iPhone via USB");
    qDebug() << "CarPlayManager initialized";
}

CarPlayManager::~CarPlayManager()
{
    stopConnection();
    cleanupUsb();
}

void CarPlayManager::startConnection()
{
    if (m_connected || m_connectionState == Connecting) {
        qDebug() << "CarPlay: Already connected or connecting";
        return;
    }

    qDebug() << "CarPlay: Starting connection...";
    setConnectionState(Detecting);
    updateConnectionStatus("Scanning for iPhone...");

    // Start USB polling to detect iPhone
    m_usbPollTimer.start();

    // Check immediately for already-connected device
    detectIPhoneDevice();
}

void CarPlayManager::stopConnection()
{
    qDebug() << "CarPlay: Stopping connection...";

    m_usbPollTimer.stop();
    m_connectionTimer.stop();

    if (m_streaming) {
        stopVideoDecoder();
        stopAudioRouter();
    }

    teardownSession();

    m_connected = false;
    m_streaming = false;
    m_deviceName.clear();

    emit connectedChanged();
    emit streamingChanged();
    emit deviceNameChanged();

    setConnectionState(Disconnected);
    updateConnectionStatus("Disconnected");
}

void CarPlayManager::reconnect()
{
    qDebug() << "CarPlay: Reconnecting...";
    stopConnection();
    QTimer::singleShot(500, this, &CarPlayManager::startConnection);
}

void CarPlayManager::sendTouchEvent(int action, int x, int y, int pointerId)
{
    if (!m_streaming) {
        return;
    }

    // Scale touch coordinates to CarPlay resolution
    // In production, this sends touch data to iPhone via USB/WiFi
    qDebug() << "CarPlay touch:" << action << "at" << x << "," << y << "pointer:" << pointerId;

    /*
     * Production implementation would:
     * 1. Create touch event packet with:
     *    - Action type (down/move/up/cancel)
     *    - X/Y coordinates (scaled to iPhone CarPlay resolution)
     *    - Pointer ID (for multi-touch)
     *    - Timestamp
     * 2. Encode packet in CarPlay protocol format
     * 3. Send via established USB/WiFi channel
     */
}

void CarPlayManager::sendMultiTouch(const QVariantList &touches)
{
    if (!m_streaming) {
        return;
    }

    // Handle multi-touch gestures (pinch, rotate, etc.)
    for (const QVariant &touch : touches) {
        QVariantMap t = touch.toMap();
        int action = t.value("action").toInt();
        int x = t.value("x").toInt();
        int y = t.value("y").toInt();
        int id = t.value("id").toInt();
        sendTouchEvent(action, x, y, id);
    }
}

void CarPlayManager::sendHomeButton()
{
    if (!m_connected) return;
    qDebug() << "CarPlay: Home button pressed";
    // Send home button event to CarPlay session
}

void CarPlayManager::sendSiriButton()
{
    if (!m_connected) return;
    qDebug() << "CarPlay: Siri button pressed";
    // Activate Siri via CarPlay
}

void CarPlayManager::sendSelectButton()
{
    if (!m_connected) return;
    qDebug() << "CarPlay: Select button pressed";
}

void CarPlayManager::sendBackButton()
{
    if (!m_connected) return;
    qDebug() << "CarPlay: Back button pressed";
}

void CarPlayManager::sendMenuButton()
{
    if (!m_connected) return;
    qDebug() << "CarPlay: Menu button pressed";
}

void CarPlayManager::sendPlayPauseButton()
{
    if (!m_connected) return;
    qDebug() << "CarPlay: Play/Pause button pressed";
}

void CarPlayManager::sendNextTrackButton()
{
    if (!m_connected) return;
    qDebug() << "CarPlay: Next track button pressed";
}

void CarPlayManager::sendPreviousTrackButton()
{
    if (!m_connected) return;
    qDebug() << "CarPlay: Previous track button pressed";
}

void CarPlayManager::sendKnobRotation(int delta)
{
    if (!m_connected) return;
    qDebug() << "CarPlay: Knob rotation:" << delta;
    // Send rotary input to CarPlay
}

void CarPlayManager::sendKnobPress()
{
    if (!m_connected) return;
    qDebug() << "CarPlay: Knob pressed";
    // Send knob press (select) to CarPlay
}

void CarPlayManager::setAudioEnabled(bool enabled)
{
    if (m_audioEnabled != enabled) {
        m_audioEnabled = enabled;
        emit audioEnabledChanged();
        qDebug() << "CarPlay audio:" << (enabled ? "enabled" : "disabled");
    }
}

void CarPlayManager::setAudioVolume(int volume)
{
    volume = qBound(0, volume, 100);
    if (m_audioVolume != volume) {
        m_audioVolume = volume;
        emit audioVolumeChanged();
        qDebug() << "CarPlay audio volume:" << volume;
    }
}

void CarPlayManager::setMicrophoneEnabled(bool enabled)
{
    if (m_microphoneEnabled != enabled) {
        m_microphoneEnabled = enabled;
        emit microphoneEnabledChanged();
        qDebug() << "CarPlay microphone:" << (enabled ? "enabled" : "disabled");
    }
}

void CarPlayManager::setNightMode(bool enabled)
{
    if (m_nightMode != enabled) {
        m_nightMode = enabled;
        emit nightModeChanged();
        qDebug() << "CarPlay night mode:" << (enabled ? "enabled" : "disabled");
        // Send night mode preference to iPhone
    }
}

void CarPlayManager::setVideoResolution(int width, int height)
{
    if (m_videoWidth != width || m_videoHeight != height) {
        m_videoWidth = width;
        m_videoHeight = height;
        emit videoSizeChanged();
        qDebug() << "CarPlay video resolution:" << width << "x" << height;
    }
}

void CarPlayManager::scanForDevices()
{
    qDebug() << "CarPlay: Scanning for devices...";
    detectIPhoneDevice();
}

QStringList CarPlayManager::availableDevices() const
{
    return m_detectedDevices;
}

void CarPlayManager::onUsbPollTimeout()
{
    detectIPhoneDevice();
}

void CarPlayManager::onConnectionTimeout()
{
    if (m_connectionState == Connecting || m_connectionState == Authenticating) {
        qDebug() << "CarPlay: Connection timeout";
        emit errorOccurred("Connection timeout - please reconnect iPhone");
        setConnectionState(Error);
        updateConnectionStatus("Connection timeout");
    }
}

void CarPlayManager::processVideoFrame()
{
    // Called when video frame is received from iPhone
    // In production, this decodes H.264 NAL units and emits videoFrameReady
    QMutexLocker locker(&m_videoMutex);

    // Placeholder: emit decoded frame
    // QImage frame = decodeCurrentFrame();
    // emit videoFrameImageReady(frame);
}

void CarPlayManager::processAudioPacket()
{
    // Called when audio data is received from iPhone
    // Routes audio to system output
    QMutexLocker locker(&m_audioMutex);

    // Placeholder: emit audio data
    // emit audioDataReady(audioBuffer);
}

void CarPlayManager::initializeUsb()
{
    qDebug() << "CarPlay: Initializing USB subsystem";

    /*
     * Production implementation:
     * 1. Initialize libusb or platform-specific USB API
     * 2. Set up hotplug callbacks for device connect/disconnect
     * 3. Request appropriate permissions
     *
     * Linux: libusb_init(), libusb_hotplug_register_callback()
     * This requires linking against libusb-1.0
     */

    m_usbHandle = nullptr; // Would be libusb_context*
}

void CarPlayManager::cleanupUsb()
{
    qDebug() << "CarPlay: Cleaning up USB subsystem";

    if (m_usbHandle) {
        // libusb_exit(m_usbHandle);
        m_usbHandle = nullptr;
    }
}

void CarPlayManager::detectIPhoneDevice()
{
    /*
     * Detection approach:
     * 1. Enumerate USB devices
     * 2. Look for Apple Vendor ID (0x05AC)
     * 3. Check for iPhone Product IDs (0x12A0-0x12AF range)
     * 4. Verify device supports CarPlay mode
     *
     * Alternative: Check /sys/bus/usb/devices/ on Linux
     */

    // Simplified detection using sysfs (Linux)
    QDir usbDir("/sys/bus/usb/devices");
    if (!usbDir.exists()) {
        qDebug() << "CarPlay: USB sysfs not available";
        return;
    }

    bool foundDevice = false;
    QString deviceName;

    QStringList devices = usbDir.entryList(QDir::Dirs | QDir::NoDotAndDotDot);
    for (const QString &device : devices) {
        QString vendorPath = usbDir.absoluteFilePath(device + "/idVendor");
        QString productPath = usbDir.absoluteFilePath(device + "/idProduct");
        QString manufacturerPath = usbDir.absoluteFilePath(device + "/manufacturer");
        QString productNamePath = usbDir.absoluteFilePath(device + "/product");

        QFile vendorFile(vendorPath);
        if (vendorFile.open(QIODevice::ReadOnly)) {
            QString vendorId = QString::fromUtf8(vendorFile.readAll()).trimmed();
            vendorFile.close();

            if (vendorId.compare("05ac", Qt::CaseInsensitive) == 0) {
                // Found Apple device
                QFile productNameFile(productNamePath);
                if (productNameFile.open(QIODevice::ReadOnly)) {
                    deviceName = QString::fromUtf8(productNameFile.readAll()).trimmed();
                    productNameFile.close();
                }

                // Check if it's an iPhone (not iPad, AirPods, etc.)
                if (deviceName.contains("iPhone", Qt::CaseInsensitive)) {
                    foundDevice = true;
                    qDebug() << "CarPlay: Found iPhone -" << deviceName;
                    break;
                }
            }
        }
    }

    if (foundDevice && !m_connected) {
        m_deviceName = deviceName;
        emit deviceNameChanged();
        emit deviceDetected(deviceName, deviceName);

        if (m_connectionState == Detecting) {
            establishCarPlaySession();
        }
    } else if (!foundDevice && m_connected) {
        // Device was disconnected
        qDebug() << "CarPlay: iPhone disconnected";
        emit deviceRemoved(m_deviceName);
        stopConnection();
    }
}

void CarPlayManager::establishCarPlaySession()
{
    qDebug() << "CarPlay: Establishing session with" << m_deviceName;

    setConnectionState(Connecting);
    updateConnectionStatus("Connecting to " + m_deviceName + "...");
    m_connectionTimer.start();

    /*
     * CarPlay session establishment (production implementation):
     *
     * 1. Open USB interface to iPhone
     * 2. Send CarPlay initialization command
     * 3. Wait for iPhone to switch to CarPlay accessory mode
     * 4. Complete authentication handshake
     * 5. Negotiate video/audio parameters:
     *    - Video: H.264, resolution, frame rate
     *    - Audio: AAC/PCM, sample rate, channels
     * 6. Start video/audio streams
     *
     * This requires the actual CarPlay protocol implementation
     * from libraries like libcarplay or openauto components.
     */

    // Simulate successful connection for UI development
    QTimer::singleShot(1500, this, [this]() {
        if (m_connectionState == Connecting) {
            setConnectionState(Authenticating);
            updateConnectionStatus("Authenticating...");

            QTimer::singleShot(1000, this, [this]() {
                if (m_connectionState == Authenticating) {
                    m_connectionTimer.stop();
                    m_connected = true;
                    emit connectedChanged();

                    startVideoDecoder();
                    startAudioRouter();

                    m_streaming = true;
                    emit streamingChanged();

                    setConnectionState(Streaming);
                    updateConnectionStatus("Connected to " + m_deviceName);

                    qDebug() << "CarPlay: Session established successfully";
                }
            });
        }
    });
}

void CarPlayManager::teardownSession()
{
    qDebug() << "CarPlay: Tearing down session";

    if (m_carplayHandle) {
        // Close CarPlay session
        // carplay_disconnect(m_carplayHandle);
        m_carplayHandle = nullptr;
    }
}

void CarPlayManager::startVideoDecoder()
{
    qDebug() << "CarPlay: Starting video decoder";

    /*
     * Video decoder implementation:
     * 1. Create H.264 decoder (use FFmpeg/libav or platform decoder)
     * 2. Configure for CarPlay NAL unit format
     * 3. Start decoder thread to process incoming frames
     * 4. Convert decoded frames to QImage/QVideoFrame for display
     *
     * Qt approach: Use QMediaPlayer with custom QAbstractVideoSurface
     * or direct FFmpeg integration for lower latency
     */

    if (!m_videoThread) {
        m_videoThread = new QThread(this);
        // Move video processing worker to thread
        // m_videoThread->start();
    }
}

void CarPlayManager::stopVideoDecoder()
{
    qDebug() << "CarPlay: Stopping video decoder";

    if (m_videoThread) {
        m_videoThread->quit();
        m_videoThread->wait();
        delete m_videoThread;
        m_videoThread = nullptr;
    }
}

void CarPlayManager::decodeH264Frame(const QByteArray &nalUnit)
{
    Q_UNUSED(nalUnit)
    // Feed NAL unit to H.264 decoder
    // Emit decoded frame when complete
}

void CarPlayManager::startAudioRouter()
{
    qDebug() << "CarPlay: Starting audio router";

    /*
     * Audio routing implementation:
     * 1. Set up audio output device (ALSA/PulseAudio on Linux)
     * 2. Configure for AAC or PCM audio from CarPlay
     * 3. Set up microphone input for Siri
     * 4. Handle audio focus/ducking with system
     *
     * CarPlay audio channels:
     * - Main audio (music, podcasts, audiobooks)
     * - Phone call audio
     * - Siri responses
     * - Navigation prompts
     * - System sounds
     */

    if (!m_audioThread) {
        m_audioThread = new QThread(this);
        // Move audio processing worker to thread
        // m_audioThread->start();
    }
}

void CarPlayManager::stopAudioRouter()
{
    qDebug() << "CarPlay: Stopping audio router";

    if (m_audioThread) {
        m_audioThread->quit();
        m_audioThread->wait();
        delete m_audioThread;
        m_audioThread = nullptr;
    }
}

void CarPlayManager::setConnectionState(ConnectionState state)
{
    if (m_connectionState != state) {
        m_connectionState = state;
        emit connectionStateChanged(state);
    }
}

void CarPlayManager::updateConnectionStatus(const QString &status)
{
    if (m_connectionStatus != status) {
        m_connectionStatus = status;
        emit connectionStatusChanged();
    }
}