#include "VBluetooth.h"

// Qt

// Project
#include "BLEScanner.h"
#include "FileHandler.h"
#include "FileSaver.h"

using namespace View;
using namespace Storage;

VBluetooth::VBluetooth(QObject *parent) : QObject(parent)
{
    // incoming
    connect(&_BLEScanner, SIGNAL(didReceiveScanForDevicesError(QBluetoothDeviceDiscoveryAgent::Error)),
            this, SLOT(onScanForDevicesError(QBluetoothDeviceDiscoveryAgent::Error)));

    connect(&_BLEScanner, SIGNAL(didFinishScan()),
            this, SLOT(onScanForDevicesFinished()));

    connect(&_BLEScanner, SIGNAL(didDiscoverDevice(QBluetoothDeviceInfo)),
            this, SLOT(onDeviceDiscovered(const QBluetoothDeviceInfo)));

    connect(&_BLEScanner, SIGNAL(didStartConnectingToDevice()),
            this, SLOT(onConnectingToDevice()));

    connect(&_BLEScanner, SIGNAL(didReceiveControllerError(QLowEnergyController::Error)),
            this, SLOT(onControllerError(QLowEnergyController::Error)));

    connect(&_BLEScanner, SIGNAL(didConnectToDevice(QBluetoothDeviceInfo)),
            this, SLOT(onConnectedToDevice(QBluetoothDeviceInfo)));

    connect(&_BLEScanner, SIGNAL(didDisconnectFromDevice(QBluetoothDeviceInfo)),
            this, SLOT(onDisconnectedFromDevice(QBluetoothDeviceInfo)));

    // outgoing
    connect(this, SIGNAL(didSelectDevice(const QString)),
            &_BLEScanner, SLOT(doSelectDevice(const QString)));

    connect(this, SIGNAL(didRequestScanForDevices()),
            &_BLEScanner, SLOT(doScanForDevices()));

    connect(this, SIGNAL(didRequestConcurrentSave(QString,QString,bool)),
            &_FileSaver, SLOT(onConcurrentSave(QString,QString,bool)));

    onLoadMyDevices();
}

/*!
 * \brief VBluetooth::onScanForDevices
 * Slot for when the user starts scanning for devices.
 * Updates the status and emits a signal to the BLEScanner to
 * begin a new scan.
 */
void VBluetooth::doScanForDevices()
{
    onUpdateStatus(tr("Scanning..."));
    bleDevices.clear();
    emit didDevicesChanged();
    emit didRequestScanForDevices();
}

/*!
 * \brief VBluetooth::onScanForDevicesError
 *  Slot called when the BLEScanner enounters an error
 * while scanning for devices
 * \param error
 */
void VBluetooth::onScanForDevicesError(QBluetoothDeviceDiscoveryAgent::Error error)
{
    switch (error) {
    case QBluetoothDeviceDiscoveryAgent::PoweredOffError:
        onUpdateStatus(tr("Error: Bluetooth module is powered off."));
        break;
    default:
        onUpdateStatus(tr("Error: Scan for devices error."));
        break;
    }
}

/*!
 * \brief VBluetooth::onDeviceDiscovered
 * Slot for when a device is discovered by the BLEScanner.
 * \param device - the BLE Device info of the discovered device
 */
void VBluetooth::onDeviceDiscovered(const QBluetoothDeviceInfo &device)
{
    VBluetoothDeviceInfo *info = new VBluetoothDeviceInfo(device);
    if (!isDeviceAlreadyPaired(device))
        bleDevices.insert(0, info);
    qDebug() << "VBluetooth: Discovered " << device.name();
    emit didDevicesChanged();
}

/*!
 * \brief VBluetooth::onScanForDevicesFinished
 *  Slot called when the scan is finished. Updates the scanning status.
 */
void VBluetooth::onScanForDevicesFinished()
{
    emit didScanFinished();
    onUpdateStatus(tr("Scan Finished."));
}

/*!
 * \brief VBluetooth::getDevices
 * Gets the BLE modelData for QML
 * \return QVariant - the modelData
 */
QVariant VBluetooth::doGetDevices()
{
    return QVariant::fromValue(bleDevices);
}

/*!
 * \brief VBluetooth::getDevices
 * Gets the paired devices BLE modelData for QML
 * \return QVariant - the modelData
 */
QVariant VBluetooth::doGetPairedDevices()
{
    return QVariant::fromValue(pairedDevices);
}

/*!
 * \brief VBluetooth::onSelectedDevice
 *  Emits a signal that the device was selected
 * \param addr - the selected BLE mac address
 */
void VBluetooth::doSelectDevice(const QString &addr)
{
    emit didSelectDevice(addr);
}

/*!
 * \brief onUpdateStatus
 *  Updates the status and emits a signal to notify the QML
 * \param message
 */
void VBluetooth::onUpdateStatus(const QString &message)
{
    status = message;
    emit didStatusChanged();
}

/*!
 * \brief VBluetooth::onConnectingToDevice
 *  Called when attempting to connect to a device
 */
void VBluetooth::onConnectingToDevice()
{
    onUpdateStatus(tr("Connecting..."));
}

/*!
 * \brief VBluetooth::controllerErrorToString
 *  Converts a QLowEnergyController::Error enum to QString
 * \param error - the QLowEnergyController::Error enum
 * \return QString - the enum converted to a QString
 */
QString VBluetooth::controllerErrorToString(QLowEnergyController::Error error)
{
    switch (error)
    {
    case QLowEnergyController::NoError:
        return tr("No Error.");
        break;
    case QLowEnergyController::UnknownError:
        return tr("Unknown Error. Is device turned off?");
        break;
    case QLowEnergyController::UnknownRemoteDeviceError:
        return tr("Unknown Remote Device Error.");
        break;
    case QLowEnergyController::NetworkError:
        return tr("Bluetooth Network Error.");
        break;
    case QLowEnergyController::InvalidBluetoothAdapterError:
        return tr("Bluetooth Adapter Error.");
        break;
    case QLowEnergyController::ConnectionError:
    case QLowEnergyController::AdvertisingError:
    case QLowEnergyController::RemoteHostClosedError:
        return tr("Connection Error.");
        break;
    default:
        const QMetaObject *mo = qt_getEnumMetaObject(error);
        int idx = mo->indexOfEnumerator(qt_getEnumName(error));
        const char *text = mo->enumerator(idx).valueToKey(error);
        if (!QString(text).isEmpty()) {
            return tr(text);
        }
    }

    return tr("Unexpected Error.");
}

/*!
 * \brief VBluetooth::onControllerError
 *  Called when BLE interface reports a controller error. Updates
 * the bluetooth status message according to the error reported.
 * \param error - the low energy controller error reported
 */
void VBluetooth::onControllerError(QLowEnergyController::Error error)
{
    onUpdateStatus(controllerErrorToString(error));
}

/*!
 * \brief VBluetooth::isDeviceAlreadyPaired
 * Determines if a device has already been paired
 * \param deviceInfo - the device info to check if paired
 * \return bool - true if already paired, false otherwise
 */
bool VBluetooth::isDeviceAlreadyPaired(const QBluetoothDeviceInfo &deviceInfo)
{
    for (QObject *device : pairedDevices) {
        VBluetoothDeviceInfo *pairedDevice = static_cast<VBluetoothDeviceInfo*>(device);
        if (pairedDevice->getAddress() == deviceInfo.address().toString())
            return true;
    }
    return false;
}

/*!
 * \brief VBluetooth::removeFromDevices
 *  Removes a device from the non-paired bluetooth devices list
 *  Adds that devices to the non-paired bluetooth devices blacklist
 * \param info - (VBluetoothDeviceInfo*) the bluetooth device info object to remove
 */
void VBluetooth::removeFromDevices(const VBluetoothDeviceInfo *info)
{
    QList<int> idxs;
    int i = 0;
    for (QObject *bleDevice : bleDevices) {
        VBluetoothDeviceInfo *device = static_cast<VBluetoothDeviceInfo*>(bleDevice);
        if (device->getAddress() == info->getAddress())
            idxs.append(i);
        ++i;
    }
    for (int i : idxs)
        bleDevices.removeAt(i);

    // update the QML
    emit didDevicesChanged();
}

/*!
 * \brief VBluetooth::onConnectedToDevice
 * Slot called when BLEScanner connects to a device. Moves a device
 * from the devices list to the my devices list
 * \param deviceInfo - (QBluetoothDeviceInfo) the device connected to
 */
void VBluetooth::onConnectedToDevice(const QBluetoothDeviceInfo &deviceInfo)
{
    VBluetoothDeviceInfo *info = new VBluetoothDeviceInfo(deviceInfo);
    info->setConnected(true);
    bool alreadyPaired = isDeviceAlreadyPaired(deviceInfo);
    if (alreadyPaired) {
        setDeviceConnected(deviceInfo, true);
    } else {
        pairedDevices.append(info);
        emit didPairedDevicesChanged();

        removeFromDevices(info);
    }
    onUpdateStatus(tr("Paired, Connected."));
}

/*!
 * \brief VBluetooth::setDeviceConnected
 *  Ensures the device displays as connected
 * \param deviceInfo - (QBluetoothDeviceInfo) contains the device information
 * \param connected - (bool) true to set connected, false to set not connected
 */
void VBluetooth::setDeviceConnected(const QBluetoothDeviceInfo &deviceInfo, const bool &connected)
{
    if (isDeviceAlreadyPaired(deviceInfo)) {
        for (QList<QObject*>::iterator iter = pairedDevices.begin(); iter != pairedDevices.end(); ++iter)
        {
            if (deviceInfo.address().toString() == ((VBluetoothDeviceInfo*)(*iter))->getAddress())
                ((VBluetoothDeviceInfo*)(*iter))->setConnected(connected);
        }
        emit didPairedDevicesChanged();
    } else {
        for (QList<QObject*>::iterator iter = bleDevices.begin(); iter != bleDevices.end(); ++iter)
        {
            if (deviceInfo.address().toString() == ((VBluetoothDeviceInfo*)(*iter))->getAddress())
                ((VBluetoothDeviceInfo*)(*iter))->setConnected(connected);
        }
        emit didDevicesChanged();
    }
}

/*!
 * \brief VBluetooth::onDisconnectedFromDevice
 *  Slot called when the BLEScanner detects that a device disconnected. Updates
 *  the status of the device to Not Connected if is has already been paired
 * \param deviceInfo - (QBluetoothDeviceInfo) contains the device information
 */
void VBluetooth::onDisconnectedFromDevice(const QBluetoothDeviceInfo &deviceInfo)
{
    setDeviceConnected(deviceInfo, false);
    emit didPairedDevicesChanged();
    onUpdateStatus(tr("Paired, Not Connected."));
}

/*!
 * \brief VBluetooth::loadMyDevices
 *  Loads previously selected devices from disk
 */
void VBluetooth::onLoadMyDevices(const QString &path)
{
    pairedDevices.clear();
    QJsonObject obj;
    if (!FileHandler::readJSON(path, obj))
    {
        LOG_EVENT(tr("Could not load my bluetooth devices from %1").arg(path));
        return;
    }

    for (const QString& key : obj.keys())
    {
        VBluetoothDeviceInfo *info = new VBluetoothDeviceInfo(key, obj[key].toString());
        pairedDevices.append(info);
    }
}

/*!
 * \brief VBluetooth::saveMyDevices
 *  Saves selected devices to disk
 */
void VBluetooth::doSaveMyDevices(const QString &path)
{
    QJsonObject obj;

    for (QList<QObject*>::iterator iter = pairedDevices.begin(); iter != pairedDevices.end(); ++iter)
        obj[((VBluetoothDeviceInfo*)(*iter))->getAddress()] = ((VBluetoothDeviceInfo*)(*iter))->getName();

    QJsonDocument document(obj);
    emit didRequestConcurrentSave(path, document.toJson(), false);
}