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#include <QFile>

#include "brightnesscontroller.h"

static const char brightnessSource[] = "/sys/class/backlight/backlight/brightness";
static const int brightnessMax = 6;
static const int brightnessMin = 1;

BrightnessController::BrightnessController(QObject *parent)
    : QObject(parent)
    , m_automatic(false)
{
    QFile brightnessfile(brightnessSource);
    if (brightnessfile.exists() && brightnessfile.open(QIODevice::ReadOnly)) {
        char data[1];
        if (brightnessfile.read(data, 1)) {
            m_brightness = static_cast<int>(data[0] - '0');
        }
    } else {
        // By default set to half
        m_brightness = (brightnessMax + brightnessMin) / 2;
    }
}

void BrightnessController::setBrightness(int brightness)
{
    if (m_brightness == brightness)
        return;

    // Valid values are between 1-6
    if (brightness < brightnessMin || brightness > brightnessMax)
        return;

    QFile brightnessfile(brightnessSource);
    if (brightnessfile.exists() && brightnessfile.open(QIODevice::WriteOnly)) {
        char data[1] = {static_cast<char>('0' + brightness)};
        if (brightnessfile.write(data, 1) == 1) {
            m_brightness = brightness;
            emit brightnessChanged(m_brightness);
        }
    } else {
        // File does not exists, simulate changes
        m_brightness = brightness;
        emit brightnessChanged(m_brightness);
    }
}

void BrightnessController::setAutomatic(bool automatic)
{
    if (m_automatic == automatic)
        return;

    m_automatic = automatic;
    emit automaticChanged(m_automatic);
}