/*
    SPDX-FileCopyrightText: 2005-2006, 2010 Tom Albers <toma@kde.org>
    SPDX-FileCopyrightText: 2006 Bram Schoenmakers <bramschoenmakers@kde.nl>

    SPDX-License-Identifier: GPL-2.0-or-later
*/

#include "slideshoweffect.h"
#include "breakbase.h"

#include <QApplication>
#include <QDebug>
#include <QDir>
#include <QLabel>
#include <QRandomGenerator>
#include <QScreen>
#include <QTimer>
#include <QVBoxLayout>

#include <KWindowSystem>

SlideEffect::SlideEffect(QObject *parent)
    : BreakBase(parent)
    , m_searchRecursive(false)
    , m_showSmallImages(false)
{
    // Make all other screens gray...
    slotGray();
    connect(qApp, &QGuiApplication::screenAdded, this, &SlideEffect::slotGray);
    connect(qApp, &QGuiApplication::screenRemoved, this, &SlideEffect::slotGray);

    m_slidewidget = new SlideWidget(nullptr);
    KWindowSystem::forceActiveWindow(m_slidewidget->winId());
    KWindowSystem::setOnAllDesktops(m_slidewidget->winId(), true);
    KWindowSystem::setState(m_slidewidget->winId(), NET::KeepAbove);
    KWindowSystem::setState(m_slidewidget->winId(), NET::FullScreen);

    setReadOnly(true);

    m_timer_slide = new QTimer(this);
    connect(m_timer_slide, &QTimer::timeout, this, &SlideEffect::slotNewSlide);
}

SlideEffect::~SlideEffect()
{
    delete m_slidewidget;
}

void SlideEffect::slotGray()
{
    // Make all other screens gray...
    setGrayEffectOnAllScreens(true);
    excludeGrayEffectOnScreen(QGuiApplication::primaryScreen());
}

bool SlideEffect::hasImages()
{
    return m_files.count() > 0;
}

void SlideEffect::activate()
{
    m_slidewidget->show();
    m_timer_slide->start(m_slideInterval * 1000);
    BreakBase::activate();
}

void SlideEffect::deactivate()
{
    m_timer_slide->stop();
    m_slidewidget->hide();
    BreakBase::deactivate();
}

void SlideEffect::loadImage()
{
    if (m_files.count() == 0)
        return;

    // Base the size on the size of the screen, for xinerama.
    const QSize size = QGuiApplication::primaryScreen()->geometry().size();

    // Do not accept images whose surface is more than 3 times smaller than
    // screen
    int min_image_surface = size.width() * size.height() / 3;
    QImage image;

    while (true) {
        // reset if all images are shown
        if (m_files_done.count() == m_files.count())
            m_files_done.clear();

        // get a not yet used image
        int j;
        QString name;
        do {
            j = QRandomGenerator::global()->bounded(m_files.count());
            name = m_files[j];
        } while (m_files_done.indexOf(name) != -1);

        // load image
        qDebug() << "Loading:" << name << "(" << j << "/" << m_files.count() << ") ";
        image.load(name);

        // Check size
        if (image.width() * image.height() >= min_image_surface || m_showSmallImages) {
            // Image is big enough, leave while loop
            m_files_done.append(name);
            break;
        } else {
            // Too small, remove from list
            m_files.removeAll(name);
            if (m_files.count() == 0) {
                // Couldn't find any image big enough, leave function
                return;
            }
        }
    }

    const Qt::AspectRatioMode mode = (m_expandImageToFullScreen) ? Qt::KeepAspectRatioByExpanding : Qt::KeepAspectRatio;
    const QImage m(image.scaled(size.width(), size.height(), mode));

    if (m.isNull())
        return;

    m_slidewidget->setImage(m);
}

void SlideEffect::findImagesInFolder(const QString &folder)
{
    if (folder.isNull())
        return;

    QDir dir(folder);

    if (!dir.exists() || !dir.isReadable()) {
        qWarning() << "Folder does not exist or is not readable: " << folder;
        return;
    }

    // TODO: make an automated filter, maybe with QImageIO.
    QStringList filters;
    filters << "*.png"
            << "*.jpg"
            << "*.jpeg"
            << "*.tif"
            << "*.tiff"
            << "*.gif"
            << "*.bmp"
            << "*.xpm"
            << "*.ppm"
            << "*.pnm"
            << "*.xcf"
            << "*.pcx";
    QStringList filtersUp;
    for (int i = 0; i < filters.size(); ++i)
        filtersUp << filters.at(i).toUpper();
    dir.setNameFilters(filters << filtersUp);
    dir.setFilter(QDir::Dirs | QDir::Files | QDir::NoSymLinks | QDir::AllDirs);

    const QFileInfoList list = dir.entryInfoList();
    for (int i = 0; i < list.count(); ++i) {
        QFileInfo fi = list.at(i);
        if (fi.isFile())
            m_files.append(fi.filePath());
        else if (fi.isDir() && m_searchRecursive && fi.fileName() != "." && fi.fileName() != "..")
            findImagesInFolder(fi.absoluteFilePath());
    }
}

void SlideEffect::slotNewSlide()
{
    if (m_files.count() == 1)
        return;

    loadImage();
}

void SlideEffect::reset(const QString &path, bool recursive, bool showSmallImages, bool expandImageToFullScreen, int slideInterval)
{
    m_files.clear();
    m_files_done.clear();
    m_basePath = path;
    m_searchRecursive = recursive;
    m_showSmallImages = showSmallImages;
    m_slideInterval = slideInterval;
    m_expandImageToFullScreen = expandImageToFullScreen;

    findImagesInFolder(path);
    qDebug() << "Amount of Files:" << m_files.count();
    QTimer::singleShot(2000, this, &SlideEffect::slotNewSlide);
}

// ------------------ Show widget

SlideWidget::SlideWidget(QWidget *parent)
    : QWidget(parent, Qt::Popup)
{
    slotDimension();
    connect(qApp, &QGuiApplication::screenAdded, this, &SlideWidget::slotDimension);
    connect(qApp, &QGuiApplication::screenRemoved, this, &SlideWidget::slotDimension);

    QVBoxLayout *boxLayout = new QVBoxLayout(this);
    boxLayout->setSpacing(0);
    boxLayout->setContentsMargins(0, 0, 0, 0);
    setLayout(boxLayout);
    m_imageLabel = new QLabel();
    m_imageLabel->setMaximumSize(width(), height());
    m_imageLabel->setAlignment(Qt::AlignCenter);
    layout()->addWidget(m_imageLabel);
}

SlideWidget::~SlideWidget()
{
}

void SlideWidget::slotDimension()
{
    const QRect rect = QGuiApplication::primaryScreen()->geometry();
    setGeometry(rect);
}

void SlideWidget::setImage(const QImage &image)
{
    m_imageLabel->setPixmap(QPixmap::fromImage(image));
}
