#ifndef ENERGYSAVER_H
#define ENERGYSAVER_H

#include <QObject>
#include <QTimer>

#ifdef ANDROID
#include <qandroidjniobject.h>
#endif

/**
 * @brief Class handling energy saving options.
 *
 * On Android devices, it locks the cpu shutdown while active. On other devices, it
 * will shut down device on timeout if the options are set accordingly and a shutdown script
 * is provided.
 *
 * In the context of the LenaPi application, it will prevent cpu shutdown on android devices while playing
 * music. On other devices, it will shutdown the device if no music has been playing and no mouse input was
 * detected for a certain time intervall.
 */
class EnergySaver : public QObject
{
    Q_OBJECT

protected:
    using QObject::QObject;

public:
    ~EnergySaver();
    /**
     * @brief Create instance if necessary. The instance will have auto shutdown disabeld.
     *
     * Used to prevent sleep on android devices.
     */
    static void init();
    /**
     * @brief Create instance if necessary, configure it and start timer.
     * @param enabledAutoShutdown Defines whether device will shutdown on inactivity using shutdownScript
     * @param interval Timer interval in seconds
     * @param shutdownScript Path to shutdown script file
     * @see EnergySaver::instance
     *
     * Instance is initialized with timeout interval and shutdown script
     * and started if the provided script exists.
     */
    static void init(int interval, const QString& shutdownScript);
    /**
     * @brief Implements the singleton pattern.
     * @return Instance of EnergySaver
     *
     * If no instance has been created yet, create new instance.
     */
    static EnergySaver *instance();

public slots:
    /**
     * @brief Deactivate energy saver, e.g., as music is currently playing
     *
     * Sets locks on adroid devics and stops shutdown-timer.
     */
    void deactivate();
    /**
     * @brief Active energy saver
     *
     * Releases locks on android devices and restarts shutdown-timer if shutdown option is set.
     */
    void activate();
    /**
     * @brief Restart shutdown timer, e.g. because of music player activity
     */
    void restartTimer();

private:
    /**
     * @brief Initialize and connect timer.
     * @param interval Timeout interval in millisecond.
     */
    void initTimer(int interval);
    void setShutdownScript(const QString& shutdownScript);
    /**
     * @brief Initializes locking or Android devices
     */
    void initAdroidLocks();
    /**
     * @brief Sets locks on Android devices to prevent sleep.
     *
     * Used to prevent cpu sleep as otherwise music will stop.
     */
    void setAndroidLock();
    /**
     * @brief Releases locks on Android devices to allow the device's cpu to go into sleep mode.
     */
    void releaseAndroidLock();
    QTimer mTimer;
    QString mShutdownScript;
    bool mIsActive{false};
    bool mIsAutoShutDownEnabled{false};

#ifdef ANDROID
    /**
     * @brief Prevent energy saving for Android devices
     */
    QAndroidJniObject m_wakeLock;
#endif

private slots:
    /**
     * @brief Behavior on timeout: shut down RaspberryPi.
     */
    void onTimeout();


};

#endif // ENERGYSAVER_H