#include "style_manager.h"

#include <LtsPluginManager/lts_plugin_loader.h>
#include <PluginInterfaces/style_plugin_interface.h>
#include <QDebug>
#include <QPluginLoader>

namespace LtsUtils
{

struct StyleManagerHandler
{
    StyleManager styleManager;
};
Q_GLOBAL_STATIC(StyleManagerHandler, s_styleManagerHandler)

StyleManager* StyleManager::getInstance()
{
    return &s_styleManagerHandler->styleManager;
}

bool StyleManager::loadStyle(const QString& stylePluginName, bool highDpi)
{
    if (m_currentStylePluginLoader != nullptr)
    {

        QObject* pluginInstance = m_currentStylePluginLoader->instance();
        StylePlugin::Plugin* sp = qobject_cast<StylePlugin::Plugin*>(pluginInstance);

        if (sp == nullptr)
        {
            qWarning() << "StyleManager::loadStyle: could not unload style plugin - wrong type ("
                       << pluginInstance->metaObject()->className() << ") - new style not loaded";
            return false;
        }

        sp->unloadStyle();

        m_currentStylePluginLoader = nullptr;
    }

    LtsPluginManager::LtsPluginLoader* pluginLoader = LtsPluginManager::LtsPluginLoader::getInstance();

    QPluginLoader* stylePluginLoader = nullptr;
    int pluginsLoaded = 0;

    std::function<bool(const LtsPluginManager::PluginInstance& pi)> loadPluginFn =
        [&stylePluginLoader, &pluginsLoaded](const LtsPluginManager::PluginInstance& pi) {
            stylePluginLoader = pi.pluginLoader;
            pluginsLoaded++;
            return true;
        };

    if (!pluginLoader->loadPlugins(LtsPluginManager::PluginType::STYLE, loadPluginFn, QStringList() << stylePluginName))
    {
        qWarning() << "StyleManager::loadStyle: Error loading Style Plugin - using default Qt style";
        return false;
    }

    if (pluginsLoaded == 0)
    {
        qWarning() << "StyleManager::loadStyle: Could not find Style Plugin" << stylePluginName
                   << "- using default Qt style";
        return false;
    }

    if (pluginsLoaded > 1)
    {
        qWarning() << "StyleManager::loadStyle: Style Plugin" << stylePluginName
                   << " is ambiguous - using default Qt style";
        return false;
    }

    if (stylePluginLoader == nullptr)
    {
        qWarning() << "StyleManager::loadStyle: No Style Plugin loader available - using default Qt style";
        return false;
    }

    StylePlugin::Plugin* sp = qobject_cast<StylePlugin::Plugin*>(stylePluginLoader->instance());

    if (sp == nullptr)
    {
        qWarning() << "StyleManager::loadStyle: could not load style plugin - wrong type ("
                   << stylePluginLoader->instance()->metaObject()->className() << ") - new style not loaded";
        return false;
    }

    sp->loadStyle(highDpi);

    m_currentStylePluginLoader = stylePluginLoader;
    m_stylePluginName = stylePluginName;
    emit signalStyleChanged(stylePluginName);

    return true;
}

} // namespace LtsUtils