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/*!
    \class DeviceManager
    \brief The main entry point when interacting with \l{Device}{Devices}

    \ingroup devices
    \inmodule libguh

    The DeviceManager holds all information about supported and configured Devices in the system.

    It is also responsible for loading Plugins and managing common hardware resources between
    \l{DevicePlugin}{device plugins}.

*/

/*!
    \enum DeviceManager::HardwareResource

    This enum type specifies hardware resources which can be requested by \l{DevicePlugin}{DevicePlugins}.

    \value HardwareResourceNone
        No Resource required.
    \value HardwareResourceRadio433
        Refers to the 433 MHz radio.
    \value HardwareResourceRadio868
        Refers to the 868 MHz radio.
    \value HardwareResourceTimer
        Refers to the global timer managed by the \l{DeviceManager}. Plugins should not create their own timers, but rather request the global timer using the hardware resources.
*/

/*!
    \enum DeviceManager::DeviceError

    This enum type specifies the errors that can happen when working with \l{Device}{Devices}.

    \value DeviceErrorNoError
        No Error. Everything went fine.
    \value DeviceErrorDeviceNotFound
        Couldn't find a \l{Device} for the given id.
    \value DeviceErrorDeviceClassNotFound
        Couldn't find a \l{DeviceClass} for the given id.
    \value DeviceErrorActionTypeNotFound
        Couldn't find the \l{ActionType} for the given id.
    \value DeviceErrorMissingParameter
        Parameters do not comply to the template.
    \value DeviceErrorPluginNotFound
        Couldn't find the Plugin for the given id.
    \value DeviceErrorSetupFailed
        Error setting up the \{Device}. It will not be functional.
*/

/*! \fn void DeviceManager::emitEvent(const Event &event)
    The DeviceManager will emit a \l{Event} described in \a event whenever a Device
    creates one. Normally only \l{GuhCore} should connect to this and execute actions
    after checking back with the \{RulesEngine}. Exceptions might be monitoring interfaces
    or similar, but you should never directly react to this in a \l{DevicePlugin}.
*/

#include "devicemanager.h"

#include "hardware/radio433.h"

#include "plugin/device.h"
#include "plugin/deviceclass.h"
#include "plugin/deviceplugin.h"

#include <QPluginLoader>
#include <QtPlugin>
#include <QDebug>
#include <QSettings>
#include <QStringList>

/*! Constructs the DeviceManager with the given \a parent. There should only be one DeviceManager in the system created by \l{GuhCore}.
    Use \c GuhCore::instance()->deviceManager() instead to access the DeviceManager.
*/
DeviceManager::DeviceManager(QObject *parent) :
    QObject(parent),
    m_radio433(0)
{
    m_pluginTimer.setInterval(15000);
    connect(&m_pluginTimer, &QTimer::timeout, this, &DeviceManager::timerEvent);

    // Give hardware a chance to start up before loading plugins etc.
    QMetaObject::invokeMethod(this, "loadPlugins", Qt::QueuedConnection);
    QMetaObject::invokeMethod(this, "loadConfiguredDevices", Qt::QueuedConnection);
    QMetaObject::invokeMethod(this, "createNewAutoDevices", Qt::QueuedConnection);
    // Make sure this is always emitted after plugins and devices are loaded
    QMetaObject::invokeMethod(this, "loaded", Qt::QueuedConnection);
}

/*! Returns all the \l{DevicePlugin}{DevicePlugins} loaded in the system. */
QList<DevicePlugin *> DeviceManager::plugins() const
{
    return m_devicePlugins.values();
}

/*! Returns the \{DevicePlugin} with the given \a id. Null if the id couldn't be found. */
DevicePlugin *DeviceManager::plugin(const PluginId &id) const
{
    return m_devicePlugins.value(id);
}

void DeviceManager::setPluginConfig(const PluginId &pluginId, const QVariantMap &pluginConfig)
{
    DevicePlugin *plugin = m_devicePlugins.value(pluginId);
    plugin->setConfiguration(pluginConfig);
    QSettings settings;
    settings.setValue(plugin->pluginId().toString(), pluginConfig);
    createNewAutoDevices();
}

QList<Vendor> DeviceManager::supportedVendors() const
{
    return m_supportedVendors.values();
}

/*! Returns all the supported \l{DeviceClass}{DeviceClasses} by all \l{DevicePlugin}{DevicePlugins} loaded in the system.
    Optionally filtered by vendorId. */
QList<DeviceClass> DeviceManager::supportedDevices(const VendorId &vendorId) const
{
    QList<DeviceClass> ret;
    if (vendorId.isNull()) {
        ret = m_supportedDevices.values();
    } else {
        foreach (const DeviceClassId &deviceClassId, m_vendorDeviceMap.value(vendorId)) {
            ret.append(m_supportedDevices.value(deviceClassId));
        }
    }
    return ret;
}

DeviceManager::DeviceError DeviceManager::discoverDevices(const DeviceClassId &deviceClassId, const QVariantMap &params) const
{
    DeviceClass deviceClass = findDeviceClass(deviceClassId);
    if (!deviceClass.isValid()) {
        return DeviceManager::DeviceErrorDeviceClassNotFound;
    }
    if (deviceClass.createMethod() != DeviceClass::CreateMethodDiscovery) {
        return DeviceManager::DeviceErrorCreationMethodNotSupported;
    }
    DevicePlugin *plugin = m_devicePlugins.value(deviceClass.pluginId());
    if (!plugin) {
        return DeviceManager::DeviceErrorPluginNotFound;
    }
    return plugin->discoverDevices(deviceClassId, params);
}

/*! Add a new configured device for the given \l{DeviceClass} and the given parameters.
 \a deviceClassId must refer to an existing \{DeviceClass} and \a params must match the parameter description in the \l{DeviceClass}.
    Optionally you can supply an id yourself if you must keep track of the added device. If you don't supply it, a new one will
    be generated.
*/
QPair<DeviceManager::DeviceError, QString> DeviceManager::addConfiguredDevice(const DeviceClassId &deviceClassId, const QList<Param> &params, const DeviceId id)
{
    DeviceClass deviceClass = findDeviceClass(deviceClassId);
    if (!deviceClass.isValid()) {
        qWarning() << "cannot find a device class with id" << deviceClassId;
        return qMakePair<DeviceError, QString>(DeviceErrorDeviceClassNotFound, deviceClassId.toString());
    }
    if (deviceClass.createMethod() == DeviceClass::CreateMethodUser) {
        return addConfiguredDeviceInternal(deviceClassId, params, id);
    }
    return qMakePair<DeviceError, QString>(DeviceErrorCreationMethodNotSupported, "CreateMethodUser");
}

QPair<DeviceManager::DeviceError, QString> DeviceManager::addConfiguredDevice(const DeviceClassId &deviceClassId, const DeviceDescriptorId &deviceDescriptorId, const DeviceId &deviceId)
{
    DeviceClass deviceClass = findDeviceClass(deviceClassId);
    if (!deviceClass.isValid()) {
        return qMakePair<DeviceError, QString>(DeviceErrorDeviceClassNotFound, deviceClassId.toString());
    }
    if (deviceClass.createMethod() != DeviceClass::CreateMethodDiscovery) {
        return qMakePair<DeviceError, QString>(DeviceErrorCreationMethodNotSupported, "CreateMethodDiscovery");
    }

    DeviceDescriptor descriptor = m_discoveredDevices.take(deviceClassId).take(deviceDescriptorId);
    if (!descriptor.isValid()) {
        return qMakePair<DeviceError>(DeviceErrorDeviceDescriptorNotFound, deviceDescriptorId.toString());
    }

    return addConfiguredDeviceInternal(deviceClassId, descriptor.params(), deviceId);
}

QPair<DeviceManager::DeviceError, QString> DeviceManager::addConfiguredDeviceInternal(const DeviceClassId &deviceClassId, const QList<Param> &params, const DeviceId id)
{
    DeviceClass deviceClass = findDeviceClass(deviceClassId);
    if (deviceClass.id().isNull()) {
        qWarning() << "cannot find a device class with id" << deviceClassId;
        return qMakePair<DeviceError, QString>(DeviceErrorDeviceClassNotFound, deviceClassId.toString());
    }

    // Make sure we have all required params
    foreach (const ParamType &paramType, deviceClass.params()) {
        bool found = false;
        foreach (const Param &param, params) {
            if (param.name() == paramType.name()) {
                found = true;
            }
        }

        if (!found) {
            qWarning() << "Missing parameter when creating device:" << paramType.name();
            return qMakePair<DeviceError, QString>(DeviceErrorMissingParameter, paramType.name());
        }
    }
    // Make sure we don't have unused params
    foreach (const Param &param, params) {
        bool found = false;
        foreach (const ParamType &paramType, deviceClass.params()) {
            if (paramType.name() == param.name()) {
                found = true;
                continue;
            }
        }
        if (!found) {
            // TODO: Check if parameter type matches
            return qMakePair<DeviceError, QString>(DeviceErrorDeviceParameterError, param.name());
        }
    }

    foreach(Device *device, m_configuredDevices) {
        if (device->id() == id) {
            return qMakePair<DeviceError, QString>(DeviceErrorDuplicateUuid, id.toString());
        }
    }

    DevicePlugin *plugin = m_devicePlugins.value(deviceClass.pluginId());
    if (!plugin) {
        qWarning() << "Cannot find a plugin for this device class!";
        return qMakePair<DeviceError, QString>(DeviceErrorPluginNotFound, deviceClass.pluginId().toString());
    }

    Device *device = new Device(plugin->pluginId(), id, deviceClassId, this);
    device->setName(deviceClass.name());
    device->setParams(params);
    if (setupDevice(device)) {
        m_configuredDevices.append(device);
    } else {
        qWarning() << "Failed to set up device.";
        return qMakePair<DeviceError, QString>(DeviceErrorSetupFailed, "Plugin failure");
    }

    storeConfiguredDevices();

    return qMakePair<DeviceError, QString>(DeviceErrorNoError, QString());
}

QPair<DeviceManager::DeviceError, QString> DeviceManager::removeConfiguredDevice(const DeviceId &deviceId)
{
    Device *device = findConfiguredDevice(deviceId);
    if (!device) {
        return qMakePair<DeviceError, QString>(DeviceErrorDeviceNotFound, deviceId.toString());
    }

    m_configuredDevices.removeAll(device);
    m_devicePlugins.value(device->pluginId())->deviceRemoved(device);

    m_pluginTimerUsers.removeAll(device);
    if (m_pluginTimerUsers.isEmpty()) {
        m_pluginTimer.stop();
    }

    device->deleteLater();

    QSettings settings;
    settings.beginGroup(deviceId.toString());
    settings.remove("");

    return qMakePair<DeviceError, QString>(DeviceErrorNoError, QString());
}

/*! Returns the \l{Device} with the given \a id. Null if the id couldn't be found. */
Device *DeviceManager::findConfiguredDevice(const DeviceId &id) const
{
    foreach (Device *device, m_configuredDevices) {
        if (device->id() == id) {
            return device;
        }
    }
    return 0;
}

/*! Returns all configured \{Device}{Devices} in the system. */
QList<Device *> DeviceManager::configuredDevices() const
{
    return m_configuredDevices;
}

/*! Returns all \l{Device}{Devices} matching the \l{DeviceClass} referred by \a deviceClassId. */
QList<Device *> DeviceManager::findConfiguredDevices(const DeviceClassId &deviceClassId) const
{
    QList<Device*> ret;
    foreach (Device *device, m_configuredDevices) {
        if (device->deviceClassId() == deviceClassId) {
            ret << device;
        }
    }
    return ret;
}

/*! For conveninece, this returns the \{DeviceClass} with the id given by \a deviceClassId.
    Note: The returned DeviceClass may be invalid.*/
DeviceClass DeviceManager::findDeviceClass(const DeviceClassId &deviceClassId) const
{
    foreach (const DeviceClass &deviceClass, m_supportedDevices) {
        if (deviceClass.id() == deviceClassId) {
            return deviceClass;
        }
    }
    return DeviceClass();
}

/*! Execute the given \{Action}.
    This will find the \l{Device} \a action refers to in \l{Action::deviceId()} and
    its \l{DevicePlugin}. Then will dispatch the execution to the \l{DevicePlugin}.*/
QPair<DeviceManager::DeviceError, QString> DeviceManager::executeAction(const Action &action)
{
    foreach (Device *device, m_configuredDevices) {
        if (action.deviceId() == device->id()) {
            // found device

            // Make sure this device has an action type with this id
            DeviceClass deviceClass = findDeviceClass(device->deviceClassId());
            bool found = false;
            foreach (const ActionType &actionType, deviceClass.actions()) {
                if (actionType.id() == action.actionTypeId()) {
                    found = true;

                    qDebug() << "checking params" << actionType.parameters().count() << action.params().count();
                    qDebug() << "action params:" << action.params();
                    QPair<bool, QString> paramCheck = verifyParams(actionType.parameters(), action.params());
                    if (!paramCheck.first) {
                        return qMakePair<DeviceError, QString>(DeviceErrorMissingParameter, paramCheck.second);
                    }
                    continue;
                }
            }
            if (!found) {
                return qMakePair<DeviceError, QString>(DeviceErrorActionTypeNotFound, action.actionTypeId().toString());
            }

            return m_devicePlugins.value(device->pluginId())->executeAction(device, action);
        }
    }
    return qMakePair<DeviceError, QString>(DeviceErrorDeviceNotFound, action.deviceId().toString());
}

void DeviceManager::loadPlugins()
{
    foreach (QObject *pluginObject, QPluginLoader::staticInstances()) {
        DevicePlugin *pluginIface = qobject_cast<DevicePlugin*>(pluginObject);
        if (pluginIface) {
            qDebug() << "*** Loaded plugin" << pluginIface->pluginName();
            pluginIface->initPlugin(this);
            foreach (const Vendor &vendor, pluginIface->supportedVendors()) {
                qDebug() << "* Loaded vendor:" << vendor.name();
                if (m_supportedVendors.contains(vendor.id())) {
                    qWarning() << "! Duplicate vendor. Ignoring vendor" << vendor.name();
                    continue;
                }
                m_supportedVendors.insert(vendor.id(), vendor);
            }

            foreach (const DeviceClass &deviceClass, pluginIface->supportedDevices()) {
                if (!m_supportedVendors.contains(deviceClass.vendorId())) {
                    qWarning() << "! Vendor not found. Ignoring device. VendorId:" << deviceClass.vendorId() << "DeviceClass:" << deviceClass.name() << deviceClass.id();
                    continue;
                }
                m_vendorDeviceMap[deviceClass.vendorId()].append(deviceClass.id());
                m_supportedDevices.insert(deviceClass.id(), deviceClass);
                qDebug() << "* Loaded device class:" << deviceClass.name();
            }
            QSettings settings;
            if (settings.contains(pluginIface->pluginId().toString())) {
                pluginIface->setConfiguration(settings.value(pluginIface->pluginId().toString()).toMap());
            }

            m_devicePlugins.insert(pluginIface->pluginId(), pluginIface);
            connect(pluginIface, &DevicePlugin::emitEvent, this, &DeviceManager::emitEvent);
            connect(pluginIface, &DevicePlugin::devicesDiscovered, this, &DeviceManager::slotDevicesDiscovered);
        }
    }
}

void DeviceManager::loadConfiguredDevices()
{
    QSettings settings;
    qDebug() << "loading devices from" << settings.fileName();
    foreach (const QString &idString, settings.childGroups()) {
        settings.beginGroup(idString);
        Device *device = new Device(PluginId(settings.value("pluginid").toString()), DeviceId(idString), DeviceClassId(settings.value("deviceClassId").toString()), this);
        device->setName(settings.value("devicename").toString());

        QList<Param> params;
        foreach (QString paramNameString, settings.childGroups()) {
            qDebug() << "got paramNameString" << paramNameString;
            settings.beginGroup(paramNameString);
            Param param(paramNameString.remove(QRegExp("Param-")));
            param.setValue(settings.value("value"));
            params.append(param);
            settings.endGroup();
        }
        qDebug() << "loaded params from config" << params;
        device->setParams(params);

        settings.endGroup();

        setupDevice(device);

        m_configuredDevices.append(device);
        qDebug() << "found stored device" << device->name() << idString;
    }
}

void DeviceManager::storeConfiguredDevices()
{
    QSettings settings;
    foreach (Device *device, m_configuredDevices) {
        settings.beginGroup(device->id().toString());
        settings.setValue("devicename", device->name());
        settings.setValue("deviceClassId", device->deviceClassId().toString());
        settings.setValue("pluginid", device->pluginId());
        foreach (const Param &param, device->params()) {
            settings.beginGroup("Param-" + param.name());
            settings.setValue("value", param.value());
            settings.endGroup();
        }
        settings.endGroup();
    }
}

void DeviceManager::createNewAutoDevices()
{
    bool haveNewDevice = false;
    foreach (const DeviceClass &deviceClass, m_supportedDevices) {
        if (deviceClass.createMethod() != DeviceClass::CreateMethodAuto) {
            continue;
        }

        qDebug() << "found auto device class" << deviceClass.name();
        DevicePlugin *plugin = m_devicePlugins.value(deviceClass.pluginId());
        bool success = false;
        do {
            QList<Device*> loadedDevices = findConfiguredDevices(deviceClass.id());
            Device *device = new Device(plugin->pluginId(), DeviceId::createDeviceId(), deviceClass.id());
            success = plugin->configureAutoDevice(loadedDevices, device);
            if (success) {
                qDebug() << "New device detected for" << deviceClass.name() << device->name();
                setupDevice(device);
                m_configuredDevices.append(device);
                haveNewDevice = true;
            } else {
                qDebug() << "No newly detected devices for" << deviceClass.name();
                delete device;
            }
        } while (success);
    }
    if (haveNewDevice) {
        storeConfiguredDevices();
    }
}

void DeviceManager::slotDevicesDiscovered(const DeviceClassId &deviceClassId, const QList<DeviceDescriptor> deviceDescriptors)
{
    QHash<DeviceDescriptorId, DeviceDescriptor> descriptorHash;
    foreach (const DeviceDescriptor &descriptor, deviceDescriptors) {
        descriptorHash.insert(descriptor.id(), descriptor);
    }
    m_discoveredDevices[deviceClassId] = descriptorHash;
    emit devicesDiscovered(deviceClassId, deviceDescriptors);
}

void DeviceManager::slotDeviceStateValueChanged(const QUuid &stateTypeId, const QVariant &value)
{
    Device *device = qobject_cast<Device*>(sender());
    if (!device) {
        return;
    }
    emit deviceStateChanged(device, stateTypeId, value);
}

void DeviceManager::radio433SignalReceived(QList<int> rawData)
{
    // TODO: this is just temporary for debugging...
    foreach (DevicePlugin *plugin, plugins()) {
        if (plugin->requiredHardware().testFlag(HardwareResourceRadio433)) {
            plugin->radioData(rawData);
        }
    }

    //    foreach (Device *device, m_configuredDevices) {
    //        DeviceClass deviceClass = m_supportedDevices.value(device->deviceClassId());
    //        DevicePlugin *plugin = m_devicePlugins.value(deviceClass.pluginId());
    //        if (plugin->requiredHardware().testFlag(HardwareResourceRadio433)) {
    //            plugin->radioData(rawData);
    //        }
    //    }
}

void DeviceManager::timerEvent()
{
    foreach (Device *device, m_configuredDevices) {
        DeviceClass deviceClass = m_supportedDevices.value(device->deviceClassId());
        DevicePlugin *plugin = m_devicePlugins.value(deviceClass.pluginId());
        if (plugin->requiredHardware().testFlag(HardwareResourceTimer)) {
            plugin->guhTimer();
        }
    }
}

bool DeviceManager::setupDevice(Device *device)
{
    DeviceClass deviceClass = findDeviceClass(device->deviceClassId());
    DevicePlugin *plugin = m_devicePlugins.value(deviceClass.pluginId());

    QList<State> states;
    foreach (const StateType &stateType, deviceClass.states()) {
        State state(stateType.id(), device->id());
        state.setValue(stateType.defaultValue());
        states.append(state);
    }
    device->setStates(states);

    if (plugin->requiredHardware().testFlag(HardwareResourceRadio433)) {
        if (!m_radio433) {
            m_radio433 = new Radio433();
            connect(m_radio433, &Radio433::dataReceived, this, &DeviceManager::radio433SignalReceived);
        }
    }

    if (plugin->requiredHardware().testFlag(HardwareResourceTimer)) {
        if (!m_pluginTimer.isActive()) {
            m_pluginTimer.start();
            // Additionally fire off one event to initialize stuff
            QTimer::singleShot(0, this, SLOT(timerEvent()));
        }
        m_pluginTimerUsers.append(device);
    }

    if (!plugin->deviceCreated(device)) {
        qWarning() << "Device setup for device" << device->name() << "failed.";
        return false;
    }

    connect(device, SIGNAL(stateValueChanged(QUuid,QVariant)), this, SLOT(slotDeviceStateValueChanged(QUuid,QVariant)));
    return true;
}

QPair<bool, QString> DeviceManager::verifyParams(const QList<ParamType> paramTypes, const QList<Param> params)
{
    foreach (const ParamType &paramType, paramTypes) {
        qDebug() << "checking paramType" << paramType.name();
        bool found = false;
        foreach (const Param &param, params) {
            qDebug() << "checking param" << param.name();
            if (param.name() == paramType.name()) {
                if (param.value().canConvert(paramType.type())) {
                    found = true;
                }
            }
        }
        if (!found) {
            return qMakePair<bool, QString>(false, paramType.name());
        }
    }
    return qMakePair<bool, QString>(true, QString());
}