/*
 * LCD Image Converter. Converts images and fonts for embedded applications.
 * Copyright (C) 2013 riuson
 * mailto: riuson@gmail.com
 *
 * This program 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.
 *
 * This program 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 "dialogupdates.h"

#include "ui_dialogupdates.h"

#include <QBuffer>
#include <QDateTime>
#include <QDomDocument>
#include <QFile>
#include <QIcon>
#include <QNetworkAccessManager>
#include <QNetworkReply>
#include <QNetworkRequest>
#include <QTextStream>
#include <QUrl>
#include <QUrlQuery>
#include <QXmlQuery>

#include "bitmaphelper.h"
#include "revisioninfo.h"

namespace AppUI
{
namespace Updates
{

DialogUpdates::DialogUpdates(QWidget* parent) : QDialog(parent), ui(new Ui::DialogUpdates)
{
  ui->setupUi(this);
  this->ui->labelStatus->setVisible(false);

  // hide ? button from title
  this->setWindowFlags(this->windowFlags() & (~Qt::WindowContextHelpButtonHint));

  // update icon
  QIcon icon;
  icon.addPixmap(QPixmap::fromImage(Parsing::Conversion::BitmapHelper::fromSvg(QString(":/images/lic_icon"), 16)));
  icon.addPixmap(QPixmap::fromImage(Parsing::Conversion::BitmapHelper::fromSvg(QString(":/images/lic_icon"), 24)));
  icon.addPixmap(QPixmap::fromImage(Parsing::Conversion::BitmapHelper::fromSvg(QString(":/images/lic_icon"), 32)));
  icon.addPixmap(QPixmap::fromImage(Parsing::Conversion::BitmapHelper::fromSvg(QString(":/images/lic_icon"), 48)));
  icon.addPixmap(QPixmap::fromImage(Parsing::Conversion::BitmapHelper::fromSvg(QString(":/images/lic_icon"), 64)));
  icon.addPixmap(QPixmap::fromImage(Parsing::Conversion::BitmapHelper::fromSvg(QString(":/images/lic_icon"), 128)));
  icon.addPixmap(QPixmap::fromImage(Parsing::Conversion::BitmapHelper::fromSvg(QString(":/images/lic_icon"), 256)));
  this->setWindowIcon(icon);

  // show local history by default
  this->showHistory();

  // focus on Close button
  this->ui->buttonBox->setFocus();

  // start download history.xml from network
  this->showUpdates();
}

DialogUpdates::~DialogUpdates() { delete ui; }

void DialogUpdates::showHistory()
{
  // XML file
  QString xml;
  {
    QFile file(":/history/changes");

    if (file.open(QIODevice::ReadOnly)) {
      QTextStream stream(&file);
      xml = stream.readAll();
      file.close();
    }
  }

  // XSL file
  QString xsl;
  {
    QFile file(":/history/xsl");

    if (file.open(QIODevice::ReadOnly)) {
      QTextStream stream(&file);
      xsl = stream.readAll();
      file.close();
    }
  }

  // CSS file
  QString style;
  {
    QFile file(":/history/style");

    if (file.open(QIODevice::ReadOnly)) {
      QTextStream stream(&file);
      style = stream.readAll();
      file.close();
    }
  }

  // transform
  QString html;

  if (this->transformHistory(xml, xsl, &html)) {
    this->ui->textBrowser->document()->setDefaultStyleSheet(style);
    this->ui->textBrowser->setHtml(html);
  }
}

void DialogUpdates::showUpdates()
{
  QNetworkAccessManager* mNetworkManager = new QNetworkAccessManager(this);
  this->connect(mNetworkManager, SIGNAL(finished(QNetworkReply*)), SLOT(networkReply(QNetworkReply*)));

  QUrl url("http://lcd-image-converter.riuson.com/history/history.xml");

  QUrlQuery query;
  query.addQueryItem("version", "2");
  url.setQuery(query.query());

  QNetworkRequest request = QNetworkRequest(url);
  QNetworkReply* reply = mNetworkManager->get(request);
  Q_UNUSED(reply);
}

void DialogUpdates::showUpdates(const QString& xml)
{
  // XSL file
  QString xsl;
  {
    QFile file(":/history/xsl");

    if (file.open(QIODevice::ReadOnly)) {
      QTextStream stream(&file);
      xsl = stream.readAll();
      file.close();
    }
  }

  // CSS file
  QString style;
  {
    QFile file(":/history/style");

    if (file.open(QIODevice::ReadOnly)) {
      QTextStream stream(&file);
      style = stream.readAll();
      file.close();
    }
  }

  // transform
  QString html;

  if (this->transformHistory(xml, xsl, &html)) {
    this->ui->textBrowser->document()->setDefaultStyleSheet(style);
    this->ui->textBrowser->setHtml(html);
  }
}

void DialogUpdates::showError(const QString& message)
{
  this->ui->labelStatus->setText(message);
  this->ui->labelStatus->setVisible(true);
}

bool DialogUpdates::transformHistory(const QString& xml, const QString& xsl, QString* html)
{
  bool isSuccessfully = false;

  // XML file
  QBuffer history;
  {
    QString value = xml;

    value.replace("<sha1>current</sha1>", QString("<sha1>%1</sha1>").arg(VersionControl::RevisionInfo::hash()));
    value.replace("<date>current</date>", QString("<date>%1</date>").arg(VersionControl::RevisionInfo::date()));

    QByteArray array = value.toUtf8();

    history.setData(array);
  }

  // XSL file
  QBuffer transform;
  {
    QString value = xsl;

    value.replace("$current_date", QString("%1").arg(VersionControl::RevisionInfo::date()));

    QByteArray array = value.toUtf8();

    transform.setData(array);
  }

  // transform
  if (history.open(QIODevice::ReadOnly)) {
    if (transform.open(QIODevice::ReadOnly)) {
      QXmlQuery query(QXmlQuery::XSLT20);

      query.setFocus(&history);
      query.setQuery(&transform);

      QString resultHtml = "";

      if (query.evaluateTo(&resultHtml)) {
        *html = resultHtml;
        isSuccessfully = true;
      }

      transform.close();
    }

    history.close();
  }

  return isSuccessfully;
}

bool DialogUpdates::isLocalVersionOutdated(const QString& xml)
{
  QDomDocument doc;

  if (doc.setContent(xml)) {
    QXmlQuery query;
    query.setFocus(xml);
    query.setQuery("/data/record/commit/date/string()");

    if (query.isValid()) {
      QStringList dates;
      query.evaluateTo(&dates);

      QString revisionDateString = VersionControl::RevisionInfo::date();
      QDateTime revisionDate = QDateTime::fromString(revisionDateString, Qt::ISODate);

      foreach (const QString& dateString, dates) {
        QDateTime date = QDateTime::fromString(dateString, Qt::ISODate);

        if (date > revisionDate) {
          return true;
        }
      }

      return false;
    }
  }

  return true;
}

void DialogUpdates::networkReply(QNetworkReply* reply)
{
  const int RESPONSE_OK = 200;

  QString replyString;

  if (reply->error() == QNetworkReply::NoError) {
    int httpStatusCode = reply->attribute(QNetworkRequest::HttpStatusCodeAttribute).toUInt();

    switch (httpStatusCode) {
      case RESPONSE_OK: {
        if (reply->isReadable()) {
          // Assuming this is a human readable file replyString now contains the file
          replyString = QString::fromUtf8(reply->readAll().data());

          if (this->isLocalVersionOutdated(replyString)) {
            this->showUpdates(replyString);
          }
        }

        break;
      }

      default: {
        QString message = tr("Check updates failed with HTTP code: %1").arg(httpStatusCode);
        this->showError(message);
        break;
      }
    }
  } else {
    QString message = tr("Check updates failed with QNetworkReply message:<br/>%1").arg(reply->errorString());
    this->showError(message);
  }

  reply->deleteLater();
}

} // namespace Updates
} // namespace AppUI