/*
Copyright (C) 2012 Sebastian Herbord. All rights reserved.

This file is part of Mod Organizer.

Mod Organizer is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

Mod Organizer is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with Mod Organizer.  If not, see <http://www.gnu.org/licenses/>.
*/

#include "moapplication.h"
#include "settings.h"
#include "env.h"
#include <iplugingame.h>
#include <report.h>
#include <utility.h>
#include <log.h>
#include "shared/appconfig.h"
#include <QFile>
#include <QStringList>
#include <QProxyStyle>
#include <QStyleFactory>
#include <QPainter>
#include <QStyleOption>
#include <QDebug>

// see addDllsToPath() below
#pragma comment(linker, "/manifestDependency:\"" \
    "name='dlls' " \
    "processorArchitecture='x86' " \
    "version='1.0.0.0' " \
    "type='win32' \"")

using namespace MOBase;


class ProxyStyle : public QProxyStyle {
public:
  ProxyStyle(QStyle *baseStyle = 0)
    : QProxyStyle(baseStyle)
  {
  }

  void drawPrimitive(PrimitiveElement element, const QStyleOption *option, QPainter *painter, const QWidget *widget) const {
    if(element == QStyle::PE_IndicatorItemViewItemDrop) {
      painter->setRenderHint(QPainter::Antialiasing, true);

      QColor col(option->palette.windowText().color());
      QPen pen(col);
      pen.setWidth(2);
      col.setAlpha(50);
      QBrush brush(col);

      painter->setPen(pen);
      painter->setBrush(brush);
      if(option->rect.height() == 0) {
        QPoint tri[3] = {
          option->rect.topLeft(),
          option->rect.topLeft() + QPoint(-5,  5),
          option->rect.topLeft() + QPoint(-5, -5)
        };
        painter->drawPolygon(tri, 3);
        painter->drawLine(QPoint(option->rect.topLeft().x(), option->rect.topLeft().y()), option->rect.topRight());
      } else {
        painter->drawRoundedRect(option->rect, 5, 5);
      }
    } else {
      QProxyStyle::drawPrimitive(element, option, painter, widget);
    }
  }
};


// This adds the `dlls` directory to the path so the dlls can be found. How
// MO is able to find dlls in there is a bit convoluted:
//
// Dependencies on DLLs can be baked into an executable by passing a
// `manifestdependency` option to the linker. This can be done on the command
// line or with a pragma. Typically, the dependency will not be a hardcoded
// filename, but an assembly name, such as Microsoft.Windows.Common-Controls.
//
// When Windows loads the exe, it will look for this assembly in a variety of
// places, such as in the WinSxS folder, but also in the program's folder. It
// will look for `assemblyname.dll` or `assemblyname/assemblyname.dll` and try
// to load that.
//
// If these files don't exist, then the loader gets creative and looks for
// `assemblyname.manifest` and `assemblyname/assemblyname.manifest`. A manifest
// file is just an XML file that can contain a list of DLLs to load for this
// assembly.
//
// In MO's case, there's a `pragma` at the beginning of this file which adds
// `dlls` as an "assembly" dependency. This is a bit of a hack to just force
// the loader to eventually find `dlls/dlls.manifest`, which contains the list
// of all the DLLs MO requires to load.
//
// This file was handwritten in `modorganizer/src/dlls.manifest.qt5` and
// is copied and renamed in CMakeLists.txt into `bin/dlls/dlls.manifest`. Note
// that the useless and incorrect .qt5 extension is removed.
//
void addDllsToPath()
{
  const auto dllsPath = QDir::toNativeSeparators(
    QCoreApplication::applicationDirPath() + "/dlls");

  QCoreApplication::setLibraryPaths(
    QStringList(dllsPath) + QCoreApplication::libraryPaths());

  env::prependToPath(dllsPath);
}


MOApplication::MOApplication(int& argc, char** argv)
  : QApplication(argc, argv)
{
  connect(&m_StyleWatcher, &QFileSystemWatcher::fileChanged, [&](auto&& file){
    log::debug("style file '{}' changed, reloading", file);
    updateStyle(file);
  });

  m_DefaultStyle = style()->objectName();
  setStyle(new ProxyStyle(style()));
  addDllsToPath();
}

MOApplication MOApplication::create(int& argc, char** argv)
{
  QApplication::setAttribute(Qt::AA_EnableHighDpiScaling);

  return MOApplication(argc, argv);
}

bool MOApplication::setStyleFile(const QString& styleName)
{
  // remove all files from watch
  QStringList currentWatch = m_StyleWatcher.files();
  if (currentWatch.count() != 0) {
    m_StyleWatcher.removePaths(currentWatch);
  }
  // set new stylesheet or clear it
  if (styleName.length() != 0) {
    QString styleSheetName = applicationDirPath() + "/" + MOBase::ToQString(AppConfig::stylesheetsPath()) + "/" + styleName;
    if (QFile::exists(styleSheetName)) {
      m_StyleWatcher.addPath(styleSheetName);
      updateStyle(styleSheetName);
    } else {
      updateStyle(styleName);
    }
  } else {
    setStyle(new ProxyStyle(QStyleFactory::create(m_DefaultStyle)));
    setStyleSheet("");
  }
  return true;
}


bool MOApplication::notify(QObject* receiver, QEvent* event)
{
  try {
    return QApplication::notify(receiver, event);
  } catch (const std::exception &e) {
    log::error(
      "uncaught exception in handler (object {}, eventtype {}): {}",
      receiver->objectName(), event->type(), e.what());
    reportError(tr("an error occurred: %1").arg(e.what()));
    return false;
  } catch (...) {
    log::error(
      "uncaught non-std exception in handler (object {}, eventtype {})",
      receiver->objectName(), event->type());
    reportError(tr("an error occurred"));
    return false;
  }
}


void MOApplication::updateStyle(const QString& fileName)
{
  if (QStyleFactory::keys().contains(fileName)) {
    setStyle(QStyleFactory::create(fileName));
    setStyleSheet("");
  } else {
    setStyle(new ProxyStyle(QStyleFactory::create(m_DefaultStyle)));
    if (QFile::exists(fileName)) {
      setStyleSheet(QString("file:///%1").arg(fileName));
    } else {
      log::warn("invalid stylesheet: {}", fileName);
    }
  }
}


MOSplash::MOSplash(
  const Settings& settings, const QString& dataPath,
  const MOBase::IPluginGame* game)
{
  const auto splashPath = getSplashPath(settings, dataPath, game);
  if (splashPath.isEmpty()) {
    return;
  }

  QPixmap image(splashPath);
  if (image.isNull()) {
    log::error("failed to load splash from {}", splashPath);
    return;
  }

  ss_.reset(new QSplashScreen(image));
  settings.geometry().centerOnMainWindowMonitor(ss_.get());

  ss_->show();
  ss_->activateWindow();
}

void MOSplash::close()
{
  if (ss_) {
    // don't pass mainwindow as it just waits half a second for it
    // instead of proceding
    ss_->finish(nullptr);
  }
}

QString MOSplash::getSplashPath(
  const Settings& settings, const QString& dataPath,
  const MOBase::IPluginGame* game) const
{
  if (!settings.useSplash()) {
    return {};
  }

  // try splash from instance directory
  const QString splashPath = dataPath + "/splash.png";
  if (QFile::exists(dataPath + "/splash.png")) {
    QImage image(splashPath);
    if (!image.isNull()) {
      return splashPath;
    }
  }

  // try splash from plugin
  QString pluginSplash = QString(":/%1/splash").arg(game->gameShortName());
  if (QFile::exists(pluginSplash)) {
    QImage image(pluginSplash);
    if (!image.isNull()) {
      image.save(splashPath);
      return pluginSplash;
    }
  }

  // try default splash from resource
  QString defaultSplash = ":/MO/gui/splash";
  if (QFile::exists(defaultSplash)) {
    QImage image(defaultSplash);
    if (!image.isNull()) {
      return defaultSplash;
    }
  }

  return splashPath;
}