/*
 * Deskflow -- mouse and keyboard sharing utility
 * Copyright (C) 2012 Symless Ltd.
 *
 * This package is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * found in the file LICENSE that should have accompanied this file.
 *
 * This package 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 this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#include "VersionChecker.h"

#include "common/constants.h"
#include "env_vars.h"

#include <QLocale>
#include <QNetworkAccessManager>
#include <QNetworkReply>
#include <QNetworkRequest>
#include <QProcess>
#include <QRegularExpression>
#include <memory>

using namespace deskflow::gui;

VersionChecker::VersionChecker(std::shared_ptr<QNetworkAccessManagerProxy> network)
    : m_network(network ? network : std::make_shared<QNetworkAccessManagerProxy>())
{
  m_network->init();
  connect(m_network.get(), &QNetworkAccessManagerProxy::finished, this, &VersionChecker::replyFinished);
}

void VersionChecker::checkLatest() const
{
  const QString url = env_vars::versionUrl();
  qDebug("checking for updates at: %s", qPrintable(url));
  auto request = QNetworkRequest(url);
  auto userAgent = QString("%1 %2 on %3").arg(kAppName, kVersion, QSysInfo::prettyProductName());
  request.setHeader(QNetworkRequest::UserAgentHeader, userAgent);
  request.setRawHeader("X-" DESKFLOW_APP_NAME "-Version", kVersion);
  request.setRawHeader("X-" DESKFLOW_APP_NAME "-Language", QLocale::system().name().toStdString().c_str());
  m_network->get(request);
}

void VersionChecker::replyFinished(QNetworkReply *reply)
{
  const auto httpStatus = reply->attribute(QNetworkRequest::HttpStatusCodeAttribute).toInt();
  if (reply->error() != QNetworkReply::NoError) {
    qWarning("version check server error: %s", qPrintable(reply->errorString()));
    qWarning("error checking for updates, http status: %d", httpStatus);
    return;
  }

  qInfo("version check server success, http status: %d", httpStatus);

  const auto newestVersion = QString(reply->readAll());
  qDebug("version check response: %s", qPrintable(newestVersion));

  if (!newestVersion.isEmpty() && compareVersions(DESKFLOW_VERSION, newestVersion) > 0) {
    qDebug("update found");
    emit updateFound(newestVersion);
  } else {
    qDebug("no updates found");
  }
}

int VersionChecker::getStageVersion(QString stage)
{
  const char *stableName = "stable";
  const char *rcName = "rc";
  const char *betaName = "beta";

  // use max int for stable so it's always the highest value.
  const int stableValue = INT_MAX;
  const int rcValue = 2;
  const int betaValue = 1;
  const int otherValue = 0;

  if (stage.isEmpty() || stage == stableName) {
    return stableValue;
  } else if (stage.toLower().startsWith(rcName)) {
    static QRegularExpression re("\\d*", QRegularExpression::CaseInsensitiveOption);
    auto match = re.match(stage);
    if (match.hasMatch()) {
      // return the rc value plus the rc number (e.g. 2 + 1)
      // this should be ok since stable is max int.
      return rcValue + match.captured(1).toInt();
    }
  } else if (stage == betaName) {
    return betaValue;
  }

  return otherValue;
}

int VersionChecker::compareVersions(const QString &left, const QString &right)
{
  if (left.compare(right) == 0)
    return 0; // versions are same.

  QStringList leftParts = left.split("-");
  QStringList rightParts = right.split("-");

  QStringList leftNumberParts = left.split(".");
  QStringList rightNumberParts = right.split(".");

  auto leftStagePart = leftParts.size() > 1 ? leftParts.at(1) : "";
  auto rightStagePart = rightParts.size() > 1 ? rightParts.at(1) : "";

  const int leftMajor = leftNumberParts.at(0).toInt();
  const int leftMinor = leftNumberParts.at(1).toInt();
  const int leftPatch = leftNumberParts.at(2).toInt();
  const int leftStage = getStageVersion(leftStagePart);

  const int rightMajor = rightNumberParts.at(0).toInt();
  const int rightMinor = rightNumberParts.at(1).toInt();
  const int rightPatch = rightNumberParts.at(2).toInt();
  const int rightStage = getStageVersion(rightStagePart);

  const bool rightWins =
      (rightMajor > leftMajor) || ((rightMajor >= leftMajor) && (rightMinor > leftMinor)) ||
      ((rightMajor >= leftMajor) && (rightMinor >= leftMinor) && (rightPatch > leftPatch)) ||
      ((rightMajor >= leftMajor) && (rightMinor >= leftMinor) && (rightPatch >= leftPatch) && (rightStage > leftStage));

  return rightWins ? 1 : -1;
}