// For license of this file, see <project-root-folder>/LICENSE.md.

#include "miscellaneous/iconfactory.h"

#include "miscellaneous/application.h"
#include "miscellaneous/settings.h"

#include <QBuffer>

IconFactory::IconFactory(QObject* parent) : QObject(parent) {}

IconFactory::~IconFactory() {
  qDebugNN << LOGSEC_GUI << "Destroying IconFactory instance.";
}

QIcon IconFactory::fromByteArray(QByteArray array) {
  if (array.isEmpty()) {
    return {};
  }

  array = QByteArray::fromBase64(array);
  QIcon icon;
  QBuffer buffer(&array);

  buffer.open(QIODevice::OpenModeFlag::ReadOnly);
  QDataStream in(&buffer);

  in.setVersion(QDataStream::Version::Qt_4_7);
  in >> icon;
  buffer.close();
  return icon;
}

QByteArray IconFactory::toByteArray(const QIcon& icon) {
  QByteArray array;
  QBuffer buffer(&array);

  buffer.open(QIODevice::OpenModeFlag::WriteOnly);
  QDataStream out(&buffer);

  out.setVersion(QDataStream::Version::Qt_4_7);
  out << icon;
  buffer.close();
  return array.toBase64();
}

QIcon IconFactory::fromTheme(const QString& name, const QString& fallback) {
  QIcon original = QIcon::fromTheme(name);

  return (original.isNull() && !fallback.isEmpty()) ? QIcon::fromTheme(fallback) : original;
}

QPixmap IconFactory::miscPixmap(const QString& name) {
  return QPixmap(QString(APP_THEME_PATH) + QDir::separator() + "misc" + QDir::separator() + name + ".png");
}

QIcon IconFactory::miscIcon(const QString& name) {
  return QIcon(QString(APP_THEME_PATH) + QDir::separator() + "misc" + QDir::separator() + name + ".png");
}

void IconFactory::setupSearchPaths() {
  auto paths = QIcon::themeSearchPaths();

  paths << APP_THEME_PATH
        << qApp->userDataFolder() + QDir::separator() + APP_LOCAL_THEME_FOLDER
        << qApp->applicationDirPath() + QDir::separator() + APP_LOCAL_THEME_FOLDER;

  QIcon::setThemeSearchPaths(paths);
  qDebugNN << LOGSEC_GUI
           << "Available icon theme paths: "
           << paths;
}

void IconFactory::setCurrentIconTheme(const QString& theme_name) {
  qApp->settings()->setValue(GROUP(GUI), GUI::IconTheme, theme_name);
}

void IconFactory::loadCurrentIconTheme() {
  const QStringList installed_themes = installedIconThemes();
  const QString theme_name_from_settings = qApp->settings()->value(GROUP(GUI), SETTING(GUI::IconTheme)).toString();

  if (QIcon::themeName() == theme_name_from_settings) {
    qDebugNN << LOGSEC_GUI << "Icon theme" << QUOTE_W_SPACE(theme_name_from_settings) << "already loaded.";
    return;
  }

  // Display list of installed themes.
  qDebugNN << LOGSEC_GUI << "Installed icon themes are: "
           << QStringList(installed_themes)
    .replaceInStrings(QRegularExpression(QSL("^|$")), QSL("\'"))
    .replaceInStrings(QRegularExpression(QSL("^\\'$")), QSL("\'\'")).join(QSL(", "));

  if (installed_themes.contains(theme_name_from_settings)) {
    // Desired icon theme is installed and can be loaded.
#if defined(Q_OS_UNIX) && !defined(Q_OS_MACOS)
    if (theme_name_from_settings.isEmpty()) {
      qDebugNN << LOGSEC_GUI << "Loading default system icon theme.";
    }
    else {
      qDebugNN << LOGSEC_GUI << "Loading icon theme" << QUOTE_W_SPACE_DOT(theme_name_from_settings);
      QIcon::setThemeName(theme_name_from_settings);
    }
#else
    qDebugNN << LOGSEC_GUI << "Loading icon theme" << QUOTE_W_SPACE_DOT(theme_name_from_settings);
    QIcon::setThemeName(theme_name_from_settings);
#endif
  }
  else {
    // Desired icon theme is not currently available.
    // Activate "default" or "no" icon theme instead.
#if defined(Q_OS_UNIX) && !defined(Q_OS_MACOS)
    qWarningNN << "Icon theme"
               << QUOTE_W_SPACE(theme_name_from_settings)
               << "cannot be loaded because it is not installed. Activating \"no\" icon theme.";
#else
    qWarningNN << "Icon theme"
               << QUOTE_W_SPACE(theme_name_from_settings)
               << "cannot be loaded because it is not installed. Activating \"no\" icon theme.";
    QIcon::setThemeName(QSL(APP_NO_THEME));
#endif
  }
}

QStringList IconFactory::installedIconThemes() const {
  QStringList icon_theme_names = { QSL(APP_NO_THEME) };

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

  filters_index.append(QSL("index.theme"));
  icon_themes_paths.removeDuplicates();

  for (const QString& icon_path : icon_themes_paths) {
    const QDir icon_dir(icon_path);
    auto icon_paths = icon_dir.entryInfoList(QDir::Filter::Dirs | QDir::Filter::NoDotAndDotDot |
                                             QDir::Filter::Readable | QDir::Filter::CaseSensitive |
                                             QDir::Filter::NoSymLinks,
                                             QDir::SortFlag::Time);

    // Iterate all icon themes in this directory.
    for (const QFileInfo& icon_theme_path : qAsConst(icon_paths)) {
      QDir icon_theme_dir = QDir(icon_theme_path.absoluteFilePath());

      if (icon_theme_dir.exists(filters_index.at(0))) {
        icon_theme_names << icon_theme_dir.dirName();
      }
    }
  }

  icon_theme_names.removeDuplicates();
  return icon_theme_names;
}