/*
Copyright (C) 2016 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 "instancemanager.h"
#include "selectiondialog.h"
#include "settings.h"
#include "shared/appconfig.h"
#include "plugincontainer.h"
#include "env.h"
#include <report.h>
#include <iplugingame.h>
#include <utility.h>
#include <log.h>

#include <QCoreApplication>
#include <QDir>
#include <QStandardPaths>
#include <QInputDialog>
#include <QMessageBox>
#include <cstdint>

using namespace MOBase;

const QString Organization = "Mod Organizer Team";
const QString Application = "Mod Organizer";
const QString InstanceValue = "CurrentInstance";


InstanceManager::InstanceManager()
  : m_AppSettings(Organization, Application)
{
  updateRegistryKey();
}

InstanceManager &InstanceManager::instance()
{
  static InstanceManager s_Instance;
  return s_Instance;
}

void InstanceManager::updateRegistryKey()
{
  const QString OldOrganization = "Tannin";
  const QString OldApplication = "Mod Organizer";
  const QString OldInstanceValue = "CurrentInstance";

  const QString OldRootKey = "Software\\" + OldOrganization;

  if (env::registryValueExists(OldRootKey + "\\" + OldApplication, OldInstanceValue)) {
    QSettings old(OldOrganization, OldApplication);
    setCurrentInstance(old.value(OldInstanceValue).toString());
    old.remove(OldInstanceValue);
  }

  env::deleteRegistryKeyIfEmpty(OldRootKey);
}

void InstanceManager::overrideInstance(const QString& instanceName)
{
  m_overrideInstanceName = instanceName;
  m_overrideInstance = true;
}

void InstanceManager::overrideProfile(const QString& profileName)
{
  m_overrideProfileName = profileName;
  m_overrideProfile = true;
}

QString InstanceManager::currentInstance() const
{
  if (m_overrideInstance)
    return m_overrideInstanceName;
  else
    return m_AppSettings.value(InstanceValue, "").toString();
}

void InstanceManager::clearCurrentInstance()
{
  setCurrentInstance("");
  m_Reset = true;
  m_overrideInstance = false;
}

void InstanceManager::setCurrentInstance(const QString &name)
{
  m_AppSettings.setValue(InstanceValue, name);
}

bool InstanceManager::deleteLocalInstance(const QString& instanceId) const
{
  QString dir = instancePath(instanceId);

  const auto Recycle = QMessageBox::Save;
  const auto Delete = QMessageBox::Yes;
  const auto Cancel = QMessageBox::Cancel;

  const auto r = MOBase::TaskDialog()
    .title(QObject::tr("Deleting instance folder"))
    .main(QObject::tr("This will delete the instance folder."))
    .content(dir)
    .icon(QMessageBox::Warning)
    .button({QObject::tr("Move the folder to the recycle bin"), Recycle})
    .button({QObject::tr("Delete the folder permanently"), Delete})
    .button({QObject::tr("Cancel"), Cancel})
    .exec();

  std::wstring error;

  switch (r)
  {
    case Recycle:
    {
      if (MOBase::shellDelete(QStringList(dir), true)) {
        return true;
      }

      const auto e = GetLastError();
      error = formatSystemMessage(e);
      log::warn("failed to move to trash '{}', {}", dir, error);

      break;
    }

    case Delete:
    {
      if (MOBase::shellDelete(QStringList(dir), false)) {
        return true;
      }

      const auto e = GetLastError();
      error = formatSystemMessage(e);
      log::warn("failed to delete '{}', {}", dir, error);

      break;
    }

    default:
    {
      return true;
    }
  }

  QMessageBox::critical(
    nullptr, QObject::tr("Error"), QObject::tr(
      "Could not delete instance folder \"%1\".\n\n%2")
        .arg(dir).arg(error),
    QMessageBox::Ok);

  return false;
}

QString InstanceManager::manageInstances(const QStringList &instanceList) const
{
  SelectionDialog selection(QString("<h3>%1</h3><br>%2")
    .arg(QObject::tr("Select an instance to delete"))
    .arg(QObject::tr(
      "Deleting an instance will delete all the mods, downloads, profiles "
      "(including profile-specific saves) and anything in the overwrite "
      "folder.<br><br>"
      "Custom paths outside of the instance folder will not be deleted.")));

  for (const QString &instance : instanceList) {
    selection.addChoice(QIcon(":/MO/gui/multiply_red"), instance, "", instance);
  }

  if (selection.exec() == QDialog::Rejected) {
    return (chooseInstance(instances()));
  }
  else {
    QString choice = selection.getChoiceData().toString();
    deleteLocalInstance(choice);
  }

  return(manageInstances(instances()));
}

QString InstanceManager::queryInstanceName(const QStringList &instanceList) const
{
  QString instanceId;
  QString dialogText;
  while (instanceId.isEmpty()) {
    QInputDialog dialog;

	  dialog.setWindowTitle(QObject::tr("Enter a Name for the new Instance"));
    dialog.setLabelText(QObject::tr("Enter a new name or select one from the suggested list: \n"
                                    "(This is just a name for the Instance and can be whatever you wish,\n"
                                    " the actual game selection will happen on the next screen regardless of chosen name)"));
    // would be neat if we could take the names from the game plugins but
    // the required initialization order requires the ini file to be
    // available *before* we load plugins
    dialog.setComboBoxItems({ "NewName", "Fallout 4", "SkyrimSE", "Skyrim", "SkyrimVR", "Fallout 3",
                              "Fallout NV", "TTW", "FO4VR", "Oblivion", "Morrowind", "Enderal" });
    dialog.setComboBoxEditable(true);

    if (dialog.exec() == QDialog::Rejected) {
      throw MOBase::MyException(QObject::tr("Canceled"));
    }
    dialogText = dialog.textValue();
    instanceId = sanitizeInstanceName(dialogText);
    if (instanceId != dialogText) {
      if (QMessageBox::question( nullptr,
                                QObject::tr("Invalid instance name"),
                                QObject::tr("The instance name \"%1\" is invalid.  Use the name \"%2\" instead?").arg(dialogText,instanceId),
                                QMessageBox::Yes | QMessageBox::No) == QMessageBox::No) {
        instanceId="";
        continue;
        }
    }

    bool alreadyExists=false;
    for (const QString &instance : instanceList) {
      if(instanceId==instance)
        alreadyExists=true;
    }
    if(alreadyExists)
    {
      QMessageBox msgBox;
      msgBox.setText( QObject::tr("The instance \"%1\" already exists.").arg(instanceId) );
      msgBox.setInformativeText(QObject::tr("Please choose a different instance name, like: \"%1 1\" .").arg(instanceId));
      msgBox.exec();
      instanceId="";
    }
  }
  return instanceId;
}


QString InstanceManager::chooseInstance(const QStringList &instanceList) const
{
  if (portableInstallIsLocked()) {
    return QString();
  }

  enum class Special : uint8_t {
    NewInstance,
    Portable,
    Manage
  };

  SelectionDialog selection(
      QString("<h3>%1</h3><br>%2")
          .arg(QObject::tr("Choose Instance"))
          .arg(QObject::tr(
              "Each Instance is a full set of MO data files (mods, "
              "downloads, profiles, configuration, ...). You can use multiple "
			  "instances for different games. Instances are stored in Appdata and can be accessed by all MO installations. "
			  "If your MO folder is writable, you can also store a single instance locally (called "
              "a Portable install, and all the MO data files will be inside the installation folder).")),
      nullptr);
  selection.disableCancel();
  for (const QString &instance : instanceList) {
    selection.addChoice(instance, "", instance);
  }

  selection.addChoice(QIcon(":/MO/gui/add"), QObject::tr("New"),
                      QObject::tr("Create a new instance."),
                      static_cast<uint8_t>(Special::NewInstance));

  if (QFileInfo(qApp->applicationDirPath()).isWritable()) {
    selection.addChoice(QIcon(":/MO/gui/package"), QObject::tr("Portable"),
                        QObject::tr("Use MO folder for data."),
                        static_cast<uint8_t>(Special::Portable));
  }

  selection.addChoice(QIcon(":/MO/gui/remove"), QObject::tr("Manage Instances"),
                        QObject::tr("Delete an Instance."),
                        static_cast<uint8_t>(Special::Manage));

  selection.setWindowFlags(selection.windowFlags() | Qt::WindowStaysOnTopHint);

  if (selection.exec() == QDialog::Rejected) {
    log::debug("rejected");
    throw MOBase::MyException(QObject::tr("Canceled"));
  }

  QVariant choice = selection.getChoiceData();

  if (choice.type() == QVariant::String) {
    return choice.toString();
  } else {
    switch (static_cast<Special>(choice.value<uint8_t>())) {
      case Special::NewInstance: return queryInstanceName(instanceList);
      case Special::Portable: return QString();
      case Special::Manage: {

        return(manageInstances(instances()));
      }
      default: throw std::runtime_error("invalid selection");
    }
  }
}

QString InstanceManager::instancePath(const QString& instanceName) const
{
  return QDir::fromNativeSeparators(instancesPath() + "/" + instanceName);
}

QString InstanceManager::instancesPath() const
{
  return QDir::fromNativeSeparators(
        QStandardPaths::writableLocation(QStandardPaths::DataLocation));
}


QStringList InstanceManager::instances() const
{
  const std::set<QString> ignore = {
    "cache", "qtwebengine",
  };

  const auto dirs = QDir(instancesPath())
    .entryList(QDir::Dirs | QDir::NoDotAndDotDot);

  QStringList list;

  for (auto&& d : dirs) {
    if (!ignore.contains(QFileInfo(d).fileName().toLower())) {
      list.push_back(d);
    }
  }

  return list;
}


bool InstanceManager::isPortablePath(const QString& dataPath)
{
  return (dataPath == qApp->applicationDirPath());
}

bool InstanceManager::portableInstall() const
{
  return QFile::exists(qApp->applicationDirPath() + "/" +
                       QString::fromStdWString(AppConfig::iniFileName()));
}


bool InstanceManager::portableInstallIsLocked() const
{
  return QFile::exists(qApp->applicationDirPath() + "/" +
                       QString::fromStdWString(AppConfig::portableLockFileName()));
}


bool InstanceManager::allowedToChangeInstance() const
{
  return !portableInstallIsLocked();
}


void InstanceManager::createDataPath(const QString &dataPath) const
{
  if (!QDir(dataPath).exists()) {
    if (!QDir().mkpath(dataPath)) {
      throw MOBase::MyException(
            QObject::tr("failed to create %1").arg(dataPath));
    } else {
      QMessageBox::information(
          nullptr, QObject::tr("Data directory created"),
          QObject::tr("New data directory created at %1. If you don't want to "
                      "store a lot of data there, reconfigure the storage "
                      "directories via settings.").arg(dataPath));
    }
  }
}


QString InstanceManager::determineDataPath()
{
  QString instanceId = currentInstance();
  if (portableInstallIsLocked())
  {
    instanceId.clear();
  }
  if (instanceId.isEmpty() && !m_Reset && (m_overrideInstance || portableInstall()))
  {
    // startup, apparently using portable mode before
    return qApp->applicationDirPath();
  }

  QString dataPath = QDir::fromNativeSeparators(
        QStandardPaths::writableLocation(QStandardPaths::DataLocation)
        + "/" + instanceId);


  if (!m_overrideInstance && (instanceId.isEmpty() || !QFileInfo::exists(dataPath))) {
    instanceId = chooseInstance(instances());
    setCurrentInstance(instanceId);
    if (!instanceId.isEmpty()) {
      dataPath = QDir::fromNativeSeparators(
        QStandardPaths::writableLocation(QStandardPaths::DataLocation)
        + "/" + instanceId);
    }
  }

  if (instanceId.isEmpty()) {
    return qApp->applicationDirPath();
  } else {
    createDataPath(dataPath);

    return dataPath;
  }
}

QString InstanceManager::determineProfile(const Settings &settings)
{
  auto selectedProfileName = settings.game().selectedProfileName();

  if (m_overrideProfile) {
    log::debug("profile overwritten on command line");
    selectedProfileName = m_overrideProfileName;
  }

  if (!selectedProfileName) {
    log::debug("no configured profile");
    selectedProfileName = "Default";
  }

  return *selectedProfileName;
}

bool InstanceManager::determineGameEdition(
  Settings& settings, IPluginGame* game)
{
  QString edition;

  if (auto v=settings.game().edition()) {
    edition = *v;
  } else {
    QStringList editions = game->gameVariants();
    if (editions.size() < 2) {
      edition = "";
      return true;
    }

    SelectionDialog selection(
      QObject::tr("Please select the game edition you have (MO can't "
        "start the game correctly if this is set "
        "incorrectly!)"),
      nullptr);

    selection.setWindowFlag(Qt::WindowStaysOnTopHint, true);

    int index = 0;
    for (const QString &edition : editions) {
      selection.addChoice(edition, "", index++);
    }

    if (selection.exec() == QDialog::Rejected) {
      return false;
    }

    edition = selection.getChoiceString();
    settings.game().setEdition(edition);
  }

  game->setGameVariant(edition);

  return true;
}

MOBase::IPluginGame *selectGame(
  Settings &settings, QDir const &gamePath, MOBase::IPluginGame *game)
{
  settings.game().setName(game->gameName());

  QString gameDir = gamePath.absolutePath();
  game->setGamePath(gameDir);

  settings.game().setDirectory(gameDir);

  return game;
}

MOBase::IPluginGame* InstanceManager::determineCurrentGame(
  const QString& moPath, Settings& settings, const PluginContainer &plugins)
{
  //Determine what game we are running where. Be very paranoid in case the
  //user has done something odd.

  //If the game name has been set up, try to use that.
  const auto gameName = settings.game().name();
  const bool gameConfigured = (gameName.has_value() && *gameName != "");

  if (gameConfigured) {
    MOBase::IPluginGame *game = plugins.managedGame(*gameName);
    if (game == nullptr) {
      reportError(
        QObject::tr("Plugin to handle %1 no longer installed. An antivirus might have deleted files.")
        .arg(*gameName));

      return nullptr;
    }

    auto gamePath = settings.game().directory();
    if (!gamePath || *gamePath == "") {
      gamePath = game->gameDirectory().absolutePath();
    }

    QDir gameDir(*gamePath);
    QFileInfo directoryInfo(gameDir.path());

    if (directoryInfo.isSymLink()) {
      reportError(QObject::tr("The configured path to the game directory (%1) appears to be a symbolic (or other) link. "
        "This setup is incompatible with MO2's VFS and will not run correctly.").arg(*gamePath));
    }

    if (game->looksValid(gameDir)) {
      return selectGame(settings, gameDir, game);
    }
  }

  //If we've made it this far and the instance is already configured for a game, something has gone wrong.
  //Tell the user about it.
  if (gameConfigured) {
    const auto gamePath = settings.game().directory();

    reportError(
      QObject::tr("Could not use configuration settings for game \"%1\", path \"%2\".")
      .arg(*gameName).arg(gamePath ? *gamePath : ""));
  }

  SelectionDialog selection(gameConfigured ?
    QObject::tr("Please select the installation of %1 to manage").arg(*gameName) :
    QObject::tr("Please select the game to manage"), nullptr, QSize(32, 32));

  for (IPluginGame *game : plugins.plugins<IPluginGame>()) {
    //If a game is already configured, skip any plugins that are not for that game
    if (gameConfigured && gameName->compare(game->gameName(), Qt::CaseInsensitive) != 0)
      continue;

    //Only add games that are installed
    if (game->isInstalled()) {
      QString path = game->gameDirectory().absolutePath();
      selection.addChoice(game->gameIcon(), game->gameName(), path, QVariant::fromValue(game));
    }
  }

  selection.addChoice(QString("Browse..."), QString(), QVariant::fromValue(static_cast<IPluginGame *>(nullptr)));

  while (selection.exec() != QDialog::Rejected) {
    IPluginGame * game = selection.getChoiceData().value<IPluginGame *>();
    QString gamePath = selection.getChoiceDescription();
    QFileInfo directoryInfo(gamePath);
    if (directoryInfo.isSymLink()) {
      reportError(QObject::tr("The configured path to the game directory (%1) appears to be a symbolic (or other) link. "
        "This setup is incompatible with MO2's VFS and will not run correctly.").arg(gamePath));
    }
    if (game != nullptr) {
      return selectGame(settings, game->gameDirectory(), game);
    }

    gamePath = QFileDialog::getExistingDirectory(nullptr, gameConfigured ?
      QObject::tr("Please select the installation of %1 to manage").arg(*gameName) :
      QObject::tr("Please select the game to manage"),
      QString(), QFileDialog::ShowDirsOnly);

    if (!gamePath.isEmpty()) {
      QDir gameDir(gamePath);
      QFileInfo directoryInfo(gamePath);
      if (directoryInfo.isSymLink()) {
        reportError(QObject::tr("The configured path to the game directory (%1) appears to be a symbolic (or other) link. "
          "This setup is incompatible with MO2's VFS and will not run correctly.").arg(gamePath));
      }
      QList<IPluginGame *> possibleGames;
      for (IPluginGame * const game : plugins.plugins<IPluginGame>()) {
        //If a game is already configured, skip any plugins that are not for that game
        if (gameConfigured && gameName->compare(game->gameName(), Qt::CaseInsensitive) != 0)
          continue;

        //Only try plugins that look valid for this directory
        if (game->looksValid(gameDir)) {
          possibleGames.append(game);
        }
      }

      if (possibleGames.count() > 1) {
        SelectionDialog browseSelection(gameConfigured ?
          QObject::tr("Please select the installation of %1 to manage").arg(*gameName) :
          QObject::tr("Please select the game to manage"),
          nullptr, QSize(32, 32));

        for (IPluginGame *game : possibleGames) {
          browseSelection.addChoice(game->gameIcon(), game->gameName(), gamePath, QVariant::fromValue(game));
        }

        if (browseSelection.exec() == QDialog::Accepted) {
          return selectGame(settings, gameDir, browseSelection.getChoiceData().value<IPluginGame *>());
        } else {
          reportError(gameConfigured ?
            QObject::tr("Canceled finding %1 in \"%2\".").arg(*gameName).arg(gamePath) :
            QObject::tr("Canceled finding game in \"%1\".").arg(gamePath));
        }
      } else if(possibleGames.count() == 1) {
        return selectGame(settings, gameDir, possibleGames[0]);
      } else {
        if (gameConfigured) {
          reportError(
            QObject::tr("%1 not identified in \"%2\". The directory is required to contain the game binary.")
            .arg(*gameName).arg(gamePath));
        } else {
          QString supportedGames;

          for (IPluginGame * const game : plugins.plugins<IPluginGame>()) {
            supportedGames += "<li>" + game->gameName() + "</li>";
          }

          QString text = QObject::tr(
            "No game identified in \"%1\". The directory is required to "
            "contain the game binary.<br><br>"
            "<b>These are the games supported by Mod Organizer:</b>"
            "<ul>%2</ul>")
            .arg(gamePath)
            .arg(supportedGames);

          reportError(text);
        }
      }
    }
  }

  return nullptr;
}


QString InstanceManager::sanitizeInstanceName(const QString &name) const
{
  QString new_name = name;

  // Restrict the allowed characters
  new_name = new_name.remove(QRegExp("[^A-Za-z0-9 _=+;!@#$%^'\\-\\.\\[\\]\\{\\}\\(\\)]"));

  // Don't end in spaces and periods
  new_name = new_name.remove(QRegExp("\\.*$"));
  new_name = new_name.remove(QRegExp(" *$"));

  // Recurse until stuff stops changing
  if (new_name != name) {
    return sanitizeInstanceName(new_name);
  }
  return new_name;
}