/**
 * Copyright (c) 2023 ~ 2024 KylinSec Co., Ltd.
 * kiran-qt5-integration is licensed under Mulan PSL v2.
 * You can use this software according to the terms and conditions of the Mulan PSL v2.
 * You may obtain a copy of Mulan PSL v2 at:
 *          http://license.coscl.org.cn/MulanPSL2
 * THIS SOFTWARE IS PROVIDED ON AN "AS IS" BASIS, WITHOUT WARRANTIES OF ANY KIND,
 * EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO NON-INFRINGEMENT,
 * MERCHANTABILITY OR FIT FOR A PARTICULAR PURPOSE.
 * See the Mulan PSL v2 for more details.
 *
 * Author:     tangjie02 <tangjie02@kylinos.com.cn>
 */

#include "plugins/platformtheme/theme.h"
#include <private/qguiapplication_p.h>
#include <private/qiconloader_p.h>
#include <private/qwidgetwindow_p.h>
#include <private/qwindow_p.h>
#include <qpa/qplatformscreen.h>
#define private public
#include <private/qhighdpiscaling_p.h>
#undef private
#include <QApplication>
#include <QGuiApplication>
#include <QIcon>
#include <QLabel>
#include <QLibraryInfo>
#include <QPixmap>
#include <QScreen>
#include <QStyle>
#include <QTimer>
#include <QTranslator>
#include <QVariant>
#include <QWindow>

#include "cmake-macros.h"
#include "gtk-file-dialog.h"
#include "lib/common/configuration.h"
#include "lib/theme/palette.h"
#include "lib/theme/style.h"
#include "plugins/platformtheme/appearance-monitor.h"
#include "plugins/platformtheme/themed-icon-engine.h"

#define THEMED_SVG_ICON_PREFIX "ksvg-"
#define THEMED_RSVG_ICON_PREFIX "krsvg-"

namespace Kiran
{
namespace Platformtheme
{
// NOTE: QPlatformTheme插件是QGuiApplication中init_platform将会进行加载的
//  1. 关于Application的调用，QPlatformTheme中只能使用QGuiApplication。
//  2. 若一定需要使用QApplication的相关方法，得先判断Qt应用代码中是否使用的是QApplication
Theme::Theme(const QStringList& paramList)
    : QGenericUnixTheme()
{
    init();
}

Theme::~Theme() = default;

bool Theme::usePlatformNativeDialog(QPlatformTheme::DialogType type) const
{
    switch (type)
    {
    case QPlatformTheme::DialogType::FileDialog:
        return true;
    default:
        break;
    }
    return QGenericUnixTheme::usePlatformNativeDialog(type);
}

QPlatformDialogHelper* Theme::createPlatformDialogHelper(QPlatformTheme::DialogType type) const
{
    switch (type)
    {
    case QPlatformTheme::DialogType::FileDialog:
        return new GtkFileDialogHelper();
    default:
        break;
    }
    return QGenericUnixTheme::createPlatformDialogHelper(type);
}

QIconEngine* Theme::createIconEngine(const QString& iconName) const
{
    if (ThemedIconEngine::isValid(iconName))
    {
        // 针对特定图标前缀的svg，跟随主题变化
        if (iconName.startsWith(THEMED_SVG_ICON_PREFIX))
        {
            return new ThemedIconEngine(iconName, ThemedIconEngine::SVG_CONVERT_COMPOSITION);
        }
        else if (iconName.startsWith(THEMED_RSVG_ICON_PREFIX))
        {
            return new ThemedIconEngine(iconName, ThemedIconEngine::SVG_CONVERT_INVERT_PIXELS);
        }
    }
    return QGenericUnixTheme::createIconEngine(iconName);
}

QPixmap Theme::standardPixmap(QPlatformTheme::StandardPixmap sp, const QSizeF& size) const
{
    return QGenericUnixTheme::standardPixmap(sp, size);
}

QIcon Theme::fileIcon(const QFileInfo& fileInfo, QPlatformTheme::IconOptions iconOptions) const
{
    return QGenericUnixTheme::fileIcon(fileInfo, iconOptions);
}

QVariant Theme::themeHint(QPlatformTheme::ThemeHint hint) const
{
    switch (hint)
    {
    case SystemIconThemeName:
        return QStringList() << m_settingsMonitor->iconTheme();
    case SystemIconFallbackThemeName:
        return QStringList() << "hicolor";
    case IconThemeSearchPaths:
        return QStringList() << ".local/share/icons"
                             << "/usr/share/icons"
                             << "/usr/local/share/icons";
    case StyleNames:
        return QStringList{"kiran", "fusion"};
    case ShowShortcutsInContextMenus:
        return false;
    default:
        break;
    }
    return QGenericUnixTheme::themeHint(hint);
}

const QPalette* Theme::palette(QPlatformTheme::Palette type) const
{
    if (type != SystemPalette)
    {
        return QGenericUnixTheme::palette(type);
    }

    Kiran::Configuration conf;
    bool enable = conf.match(qAppName());
    if (!enable)
    {
        return QGenericUnixTheme::palette(type);
    }

    static QPalette themePalette;
    Kiran::Theme::Palette::getDefault()->polish(themePalette);
    return &themePalette;
}

void Theme::init()
{
    Kiran::Configuration conf;

    // 加载内部kiran-integration翻译
    QTranslator* integrationTranslator = new QTranslator(this);
    integrationTranslator->load(QLocale(), "kiran-integration", ".", KQI_INSTALL_TRANSLATIONDIR);
    qApp->installTranslator(integrationTranslator);

    // 加载qt5-qttranslations翻译
    QTranslator* qtTranslator = new QTranslator(this);
    qtTranslator->load(QLocale(), "qt", "_", QLibraryInfo::location(QLibraryInfo::TranslationsPath));
    qApp->installTranslator(qtTranslator);

    // 初始化GTK相关全局变量, 后续需使用GtkFileChooser相关功能
    GtkFileDialogHelper::ensureGtkInitialized();

    // 较新版本Q5(目前发现5.15.10)
    // 不遵循PlatformTheme::themeHint ShowShortcutsInContextMenus来禁用菜单快捷键显示(#115801)
    // 1. init_platform中会先创建PlatformTheme后再设置该属性，需延迟设置
    // 2. 需判断当前应用是否是Kiran相关应用，避免覆盖其他应用配置
    // see also:
    // https://github.com/qt/qtbase/commit/68297195759492594ac4143b7f208e17fe6f594b
#if QT_VERSION >= QT_VERSION_CHECK(5, 10, 0)
    if ( conf.match(qAppName()) )
    {
        QTimer::singleShot(0, this,[]() {
            qDebug() << "kiran-integration disable shortcuts in context menus for" << qAppName();
            QGuiApplication::setAttribute(Qt::AA_DontShowShortcutsInContextMenus,true);
        });
    }
#endif

    qDebug() << "init kiran theme...";
    m_settingsMonitor = AppearanceMonitor::instance();

    // 根据当前初始明暗主题设定调色板，
    if (!m_settingsMonitor->gtkTheme().contains("dark"))
    {
        Kiran::Theme::Palette::getDefault()->setBaseColors(Kiran::Theme::g_lightBaseColors);
    }

    m_scaleFactor = m_settingsMonitor->scaleFactor();
    qDebug() << "\tscale factor:" << m_scaleFactor;

    updateAppFont(m_settingsMonitor->appFont().family(),
                  m_settingsMonitor->appFont().pointSize());
    qDebug() << "\tapplication font:" << m_settingsMonitor->appFont().family()
             << m_settingsMonitor->appFont().pointSize();

    m_titleBarFont.setFamily(m_settingsMonitor->titleBarFont().family());
    m_titleBarFont.setPointSize(m_settingsMonitor->titleBarFont().pointSize());
    qDebug() << "\ttitle bar font:" << m_settingsMonitor->titleBarFont().family() << m_settingsMonitor->titleBarFont().pointSize();

    QObject::connect(m_settingsMonitor, &AppearanceMonitor::appFontChanged, this, &Theme::handleAppFontChanged);
    QObject::connect(m_settingsMonitor, &AppearanceMonitor::titleBarFontChanged, this, &Theme::handleTitleBarFontChanged);
    QObject::connect(m_settingsMonitor, &AppearanceMonitor::iconThemeChanged, this, &Theme::handleIconThemeChanged);
    QObject::connect(m_settingsMonitor, &AppearanceMonitor::scaleFactorChanged, this, &Theme::handleScaleFactorChanged);
    QObject::connect(m_settingsMonitor, &AppearanceMonitor::cursorThemeChanged, this, &Theme::handleCursorThemeChanged);
    QObject::connect(m_settingsMonitor, &AppearanceMonitor::gtkThemeChanged, this, &Theme::handleThemeChanged);
    QObject::connect(qApp, &QGuiApplication::screenAdded, this, &Theme::handleScreenAdded);

    handleScaleFactorChanged(m_scaleFactor);
}

void Theme::updateAppFont(const QString& fontFamily, int pointSize)
{
    m_systemFont.setFamily(fontFamily);
    m_systemFont.setPointSize(pointSize);

    auto coreApp = QGuiApplication::instance();
    if (!qobject_cast<QApplication*>(coreApp))
    {
        // FIXME: 使用QGuiApplication更新字体不全
        QGuiApplication::setFont(m_systemFont);
    }
    else
    {
        QApplication::setFont(m_systemFont);
    }
}

const QFont* Theme::font(QPlatformTheme::Font type) const
{
    switch (type)
    {
    case QPlatformTheme::TitleBarFont:
    {
        static QFont titleBarFont = QFont(QString());
        titleBarFont.setFamily(m_titleBarFont.family());
        titleBarFont.setPointSize(m_titleBarFont.pointSize());
        return &titleBarFont;
    }
    case SystemFont:
    case FixedFont:
    {
        static QFont tempFont = QFont(QString());
        tempFont.setFamily(m_systemFont.family());
        tempFont.setPointSize(m_systemFont.pointSize());
        return &tempFont;
    }
    default:
        break;
    }

    return QGenericUnixTheme::font(type);
}

// NOTE:也可通过删除QGuiApplication::app_font,对qapp下的所有window发送ApplicationFontChanged事件
// 但是若是设置了样式表(setStyleSheet)会抑制字体的传递。该方法可能耗资源更少
void Theme::handleAppFontChanged()
{
    qDebug() << "application font changed:"
             << m_settingsMonitor->appFont().family()
             << m_settingsMonitor->appFont().pointSize();

    updateAppFont(m_settingsMonitor->appFont().family(),
                  m_settingsMonitor->appFont().pointSize());
}

void Theme::handleTitleBarFontChanged()
{
    qDebug() << "title bar font changed:"
             << m_settingsMonitor->titleBarFont().family()
             << m_settingsMonitor->titleBarFont().pointSize();

    m_titleBarFont.setFamily(m_settingsMonitor->titleBarFont().family());
    m_titleBarFont.setPointSize(m_settingsMonitor->titleBarFont().pointSize());

    // 遍历所有窗口，判断是否是KiranWidget中的自定义标题栏修改其标题栏字体
    for (auto window : qGuiApp->allWindows())
    {
        if (window->inherits("QWidgetWindow"))
        {
            auto widgetWindow = static_cast<QWidgetWindow*>(window);
            if (widgetWindow->widget() && widgetWindow->widget()->inherits("KiranTitlebarWindow"))
            {
                auto titleBarWidget = widgetWindow->widget();
                auto titleLabel = titleBarWidget->findChild<QLabel*>("KiranTitlebarTitle");
                titleLabel->setFont(m_titleBarFont);
            }
        }
    }
}

void Theme::handleScaleFactorChanged(int factor)
{
    qDebug() << "scale factor changed:"
             << m_settingsMonitor->scaleFactor();

    // 缩放的话，同时也应该调整设置到窗口管理器的边缘阴影属性
    if (enableRealTimeScaling())
    {
        if (factor == 0)  // 自动缩放
        {
            // QPlatformScreen* screenHandle = screen->handle();
            // qInfo() << screenHandle->name();
            // qInfo() << "\t logical dpi:" << screenHandle->logicalDpi();
            // qInfo() << "\t pixel density:" << screenHandle->pixelDensity();
            // TODO:清空全局分辨率,对每个屏幕单独设置分辨率
        }
        else if (factor == 1 || factor == 2)  // 手动固定分辨率
        {
            qDebug() << "update scale factor:" << factor;
            if (qFuzzyCompare(QHighDpiScaling::m_factor, factor))
            {
                return;
            }

            // 清空屏幕的子缩放率
            {
                for (QScreen* screen : qGuiApp->screens())
                {
                    if (!qFuzzyCompare(QHighDpiScaling::screenSubfactor(screen->handle()), 1))
                    {
                        QHighDpiScaling::setScreenFactor(screen, 1);
                    }
                }
            }

            // 设置全局缩放率
            QHighDpiScaling::setGlobalFactor(factor);

            {
                for (QScreen* s : qGuiApp->screens())
                {
                    Q_EMIT s->geometryChanged(s->geometry());
                }
            }

            // 更新窗口大小
            {
                for (QWindow* window : QGuiApplication::allWindows())
                {
                    if (window->type() == Qt::ForeignWindow || window->type() == Qt::Desktop)
                    {
                        return;
                    }

                    if (!window->handle() || !window->isTopLevel())
                        return;

                    const QRect currentGeo = QWindowPrivate::get(window)->geometry;
                    if (!currentGeo.isValid())
                        return;

                    // qInfo() << window->type();
                    // qInfo() << "current geo:" << currentGeo;
                    QRect nativeGeo = window->handle()->geometry();
                    qreal scale = QHighDpiScaling::factor(window);
                    nativeGeo.setSize(currentGeo.size() * scale);
                    // qInfo() << "native geo:" << nativeGeo;

                    window->handle()->setGeometry(nativeGeo);
                    QEvent event(QEvent::UpdateRequest);
                    QGuiApplication::sendEvent(window, &event);
                }
            }
        }
        else
        {
            qDebug() << "not support this factor:" << factor;
            return;
        }
    }
    else
    {
        qDebug() << "disable real time scaling,ignore scale factor changed!";
    }
}

void Theme::handleCursorThemeChanged()
{
    // 强制让窗口更新光标
    QGuiApplication::setOverrideCursor(QCursor());
    QGuiApplication::restoreOverrideCursor();
}

bool Theme::enableRealTimeScaling()
{
    static bool enable = !qEnvironmentVariableIsSet("QT_DEVICE_PIXEL_RATIO") &&
                         !qEnvironmentVariableIsSet("QT_SCALE_FACTOR") &&
                         !qEnvironmentVariableIsSet("QT_AUTO_SCREEN_SCALE_FACTOR") &&
                         !qEnvironmentVariableIsSet("QT_SCREEN_SCALE_FACTORS") &&
                         !QCoreApplication::testAttribute(Qt::AA_DisableHighDpiScaling) &&
                         !QCoreApplication::testAttribute(Qt::AA_EnableHighDpiScaling) &&
                         qGuiApp->platformName().endsWith("xcb");
    return enable;
}

void Theme::handleScreenAdded(QScreen* screen)
{
    if (m_scaleFactor == 0)  // 计算并自动调整该屏幕的缩放
    {
        // TODO:根据QPlatformTheme中的pixel density设置该屏幕子分辨率
    }
    else if (m_scaleFactor == 1 || m_scaleFactor == 2)
    {
        // TODO:应用全局分辨率至屏幕上
    }
}

void Theme::handleIconThemeChanged()
{
    qInfo() << "update icon theme:" << m_settingsMonitor->iconTheme();
    QIconLoader::instance()->updateSystemTheme();

    // 通知所有窗口重绘制
    QEvent update(QEvent::UpdateRequest);
    for (QWindow* window : qGuiApp->allWindows())
    {
        if (window->type() == Qt::Desktop)
            continue;

        qApp->sendEvent(window, &update);
    }
}

void Theme::handleThemeChanged()
{
    auto themeName = m_settingsMonitor->gtkTheme();

    if (themeName.compare("kiran") == 0)
    {
        Kiran::Theme::Palette::getDefault()->setBaseColors(Kiran::Theme::g_lightBaseColors);
    }
    else
    {
        Kiran::Theme::Palette::getDefault()->setBaseColors(Kiran::Theme::g_darkBaseColors);
    }

    QTimer::singleShot(0, [this]
                       {
                           // 此事件会促使QGuiApplication重新从QPlatformTheme中获取系统级别的QPalette
                           QWindowSystemInterfacePrivate::ThemeChangeEvent event(nullptr);

                           ///NOTE:
                           ///QGuiApplicationPrivate::processThemeChanged -> QGuiApplicationPrivate::notifyThemeChanged
                           ///5.11.1
                           /// QGuiApplicationPrivate::notifyThemeChanged若非特殊设置过Palette，是直接清空QGuiApplicajtionPrivate::app_pal,
                           /// 然后重新从QPlatformTheme之中取出system palette,重新构建QGuiApplicajtionPrivate::app_pal
                           ///5.15.2
                           /// QGuiApplicationPrivate::app_pal初始化
                           /// 默认初始化一个QPalette,若QAGuiApplicationPrivate::app_pal不存在，则调用qpalette.cpp之中qt_palette_from_color构造一个
                           /// QGuiApplicationPrivate::app_pal会采用上述的QPalette作为默认值
                           ///
                           /// 后续调用processThemeChanged->updatePalette,都只是QGuiApplicationPrivate::app_pal从QPlatformTheme::palette(system)之中取出缺失的
                           /// 所以QGuiApplicationPrivate::app_pal第一次初始化后，第一次主题应用能更新系统级别QPalette，但是之后主题变更应用不了

                           ///FIXME:
                           ///1.后续看是否有更好的方式能应用更新系统级别QPalette
                           ///2.加入判断是否外部自定义设置Application palette，若外部自定义设置了，则应不做处理

                           QPalette* oldPalette = nullptr;
                           oldPalette = QGuiApplicationPrivate::app_pal;

                           QGuiApplicationPrivate::app_pal = new QPalette(*palette(SystemPalette));

                           delete oldPalette;

                           // 该接口原本用于windows通知窗口主题变化时使用,现用来通知调用QGuiApplicationPrivate::notifyThemeChanged
                           QGuiApplicationPrivate::processThemeChanged(&event);
                           emit qApp->paletteChanged(*palette(SystemPalette));
                       });
}

}  // namespace Platformtheme
}  // namespace Kiran