#include <QIcon>
#include <QFile>
#include <QDir>
#include <QApplication>

#include "gui/themefactory.h"
#include "qtsingleapplication/qtsingleapplication.h"
#include "core/settings.h"
#include "core/defs.h"


QEvent::Type ThemeFactoryEvent::m_typeOfEvent = QEvent::None;

//
// ThemeFactoryEvent class
//

ThemeFactoryEvent::ThemeFactoryEvent() : QEvent(ThemeFactoryEvent::type()) {
}

ThemeFactoryEvent::~ThemeFactoryEvent() {
}

QEvent::Type ThemeFactoryEvent::type()  {
  if (m_typeOfEvent == QEvent::None) {
    m_typeOfEvent = static_cast<QEvent::Type>(QEvent::registerEventType(2000));
  }

  return m_typeOfEvent;
}


//
// ThemeFactory class
//

ThemeFactory::ThemeFactory() {
}

void ThemeFactory::setupSearchPaths() {
  QIcon::setThemeSearchPaths(QIcon::themeSearchPaths() << APP_THEME_PATH);
  qDebug("Available icon theme paths: %s.",
         qPrintable(QIcon::themeSearchPaths().join(", ")));
}

QString ThemeFactory::getCurrentIconTheme() {
  QString current_theme_name = Settings::getInstance()->value(APP_CFG_GUI,
                                                              "icon_theme",
                                                              "mini-kfaenza").toString();
  return current_theme_name;
}

QIcon ThemeFactory::fromTheme(const QString &name, const QIcon &fallback) {
  return QIcon::fromTheme(name, fallback);
}

void ThemeFactory::setCurrentIconTheme(const QString &theme_name) {
  Settings::getInstance()->setValue(APP_CFG_GUI,
                                    "icon_theme",
                                    theme_name);
  loadCurrentIconTheme();
}

void ThemeFactory::loadCurrentIconTheme() {
  QString theme_name = getCurrentIconTheme();
  QStringList installed_themes = getInstalledIconThemes();

  qDebug("Installed icon themes are: %s.",
         qPrintable(installed_themes.join(", ")));

  if (!installed_themes.contains(theme_name)) {
    qDebug("Icon theme '%s' cannot be loaded because it is not installed.",
           qPrintable(theme_name));
    return;
  }
  else {
    qDebug("Loading theme '%s'.", qPrintable(theme_name));
    QIcon::setThemeName(theme_name);

    // In Linux, we need to deliver custom event for all widgets
    // to make sure they get a chance to redraw their icons.
    // NOTE: This is NOT necessarily needed on Windows.
    foreach (QWidget *widget, QtSingleApplication::allWidgets()) {
      QtSingleApplication::postEvent((QObject*) widget,
                                     new ThemeFactoryEvent());
    }
  }
}

QStringList ThemeFactory::getInstalledIconThemes() {
  QStringList icon_theme_names;

#if defined(Q_OS_LINUX)
  // Add system theme on Linux, it is denoted as empty string.
  icon_theme_names << APP_THEME_SYSTEM;
#endif

  // Iterate all directories with icon themes.
  QStringList icon_themes_paths = QIcon::themeSearchPaths();
  icon_themes_paths.removeDuplicates();

  foreach (QString icon_path, icon_themes_paths) {
    QDir icon_dir(icon_path);

    // Iterate all icon themes in this directory.
    foreach (QString icon_theme_path, icon_dir.entryList(QDir::Dirs | QDir::NoDotAndDotDot |
                                                         QDir::Readable | QDir::CaseSensitive |
                                                         QDir::NoSymLinks,
                                                         QDir::Time)) {
      // Check if index.theme file in this path exists.
      if (QFile::exists(icon_dir.path() + "/" + icon_theme_path + "/index.theme")) {
        icon_theme_names << icon_theme_path;
      }
    }
  }

  icon_theme_names.removeDuplicates();
  return icon_theme_names;
}