/*
3proxy-eagle: Accumulate ethical 3proxy statistics with web interface.
Source code: https://notabug.org/acetone/3proxy-eagle.
Copyright (C) 2022, acetone

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 <https://www.gnu.org/licenses/>.
*/

#include "webpage.h"
#include "g.h"
#include "statistics.h"

#include <QFile>
#include <QDebug>
#include <cmath>
#include <algorithm>

const QString WebPage::m_lastDestinationItem = "\
          <li class=\"lastDestinations__item lastDestinations__item_allowed\" title=\"{{VALUE}}\">\n\
            {{VALUE}}\n\
          </li>\n";
const QString WebPage::m_dailyTopDestinationItem = "\
            <li class=\"topDestinations__item\" title=\"{{VALUE}}\">\n\
              {{VALUE}}\n\
            </li>\n";
const QString WebPage::m_totalTopDestinationItem = "\
            <li class=\"topDestinations__item\" title=\"{{VALUE}}\">\n\
              {{VALUE}}\n\
            </li>\n";

const QString WebPage::m_blockedDestinationsBlock = "\
      <section class=\"proxyService__blockedDestinations blockedDestinations section\">\n\
        <div class=\"blockedDestinations__title section__title\">\n\
          Blocked destinations\n\
        </div>\n\
        <ul class=\"blockedDestinations__list accordeo\">\n\
{{VALUE}}\n\
        </ul>\n\
      </section>\n";

const QString WebPage::m_blockedDestinationItemLvl1 = "\
          <li class=\"blockedDestinations__item accordeo__item\">\n\
            <label class=\"blockedDestinations__url accordeo__visible\" for=\"{{VALUE}}\">\n\
              {{VALUE}}\n\
            </label>\n\
            <input type=\"radio\" class=\"accordeo__radio\" name=\"blockedDestinations__accordeo\" id=\"{{VALUE}}\">\n\
            <ul class=\"blockedDestinations__ipList accordeo__dropdown\">\n\
{{LIST}}\n\
            </ul>\n\
          </li>\n";

const QString WebPage::m_blockedDestinationItemLvl2 = "\
              <li class=\"blockedDestinations__ipItem\">\n\
                {{VALUE}}\n\
              </li>\n";

const QString WebPage::m_informationBlock = "\
        <section class=\"proxyService__information information section\">\n\
          <div class=\"information__title section__title\">\n\
            Information\n\
          </div>\n\
          <div class=\"information__text\">\n\
            {{VALUE}}\n\
          </div>\n\
        </section>\n";

QByteArray WebPage::document()
{
    QFile src(":/html/index.html");
    if (not src.open(QIODevice::ReadOnly))
    {
        qCritical() << "Can not read built-in index.html";
        return QByteArray();
    }

    QString page = src.readAll();
    src.close();

    setTitle(page);
    customStyles(page);
    lastDestinations(page);
    trafficBlock(page);
    topDestinations(page);
    blockedDestinations(page);
    informationBlock(page);
    copyright(page);

    return page.toUtf8();
}

void WebPage::setTitle(QString &document)
{
    document.replace(g::c::HA_PAGE_TITLE, g::p::SERVICE_TITLE);
}

void WebPage::customStyles(QString &document)
{
    bool exists = QFile::exists(g::p::WORKING_DIR + "/html/styles.css");
    document.replace(g::c::HA_CUSTOM_CSS, exists ? "\n  <link rel=\"stylesheet\" href=\"/styles.css\">" : "");
}

void WebPage::lastDestinations(QString &document)
{
    QStringList dests = Statistics::lastDestinations();
    QString destinationsBlock;
    for (const auto& dest: dests)
    {
        destinationsBlock += lastDestinationItem(dest);
    }
    document.replace(g::c::HA_LAST_DESTINATIONS_LIST, destinationsBlock);
}

void WebPage::trafficBlock(QString &document)
{
    auto dailyUpload = bytesToHumanReadableString( Statistics::dailyUpload() );
    document.replace(g::c::HA_DAILY_UPLOAD, dailyUpload.first);
    document.replace(g::c::HA_DAILY_UPLOAD_MEASURE, dailyUpload.second);

    auto dailyDownload = bytesToHumanReadableString( Statistics::dailyDownload() );
    document.replace(g::c::HA_DAILY_DOWNLOAD, dailyDownload.first);
    document.replace(g::c::HA_DAILY_DOWNLOAD_MEASURE, dailyDownload.second);

    auto totalUpload = bytesToHumanReadableString( Statistics::totalUpload() );
    document.replace(g::c::HA_TOTAL_UPLOAD, totalUpload.first + " " + totalUpload.second);

    auto totalDownload = bytesToHumanReadableString( Statistics::totalDownload() );
    document.replace(g::c::HA_TOTAL_DOWNLOAD, totalDownload.first + " " + totalDownload.second);
}

void WebPage::topDestinations(QString &document)
{
    QString dailyTopList;
    for (const auto& dTop: Statistics::dailyTopDestinations())
    {
        dailyTopList += dailyTopDestinationItem(dTop);
    }
    document.replace(g::c::HA_DAILY_TOP_DESTINATIONS_LIST, dailyTopList);

    QString totalTopList;
    for (const auto& dTop: Statistics::totalTopDestinations())
    {
        totalTopList += totalTopDestinationItem(dTop);
    }
    document.replace(g::c::HA_TOTAL_TOP_DESTINATIONS_LIST, totalTopList);
}

void WebPage::blockedDestinations(QString &document)
{
    QMap<QString,QSet<QString>> uniqueRecords;

    QString blockedDestinationsBlock {m_blockedDestinationsBlock};
    QString blockedDestinationsList;
    for (const auto& inst: g::instanses)
    {
        QMapIterator<QString, QStringList> mIter(inst.second->blackList());
        while (mIter.hasNext())
        {
            auto record = mIter.next();
            for (const auto& addr: record.value())
            {
                uniqueRecords[record.key()].insert(addr);
            }

            if (not uniqueRecords.contains(record.key()))
            {
                uniqueRecords.insert(record.key(), QSet<QString>());
            }
        }
    }

    QMapIterator<QString,QSet<QString>> mIter(uniqueRecords);
    while (mIter.hasNext())
    {
        auto record = mIter.next();
        blockedDestinationsList += blockedDestinationItem(record.key(), record.value().values());
    }

    blockedDestinationsBlock.replace("{{VALUE}}", blockedDestinationsList);
    document.replace(g::c::HA_BLOCKED_DESTINTIONS, blockedDestinationsList.isEmpty() ? "" : "\n"+blockedDestinationsBlock);
}

void WebPage::informationBlock(QString &document)
{
    QFile f(g::p::WORKING_DIR + "/information.html");
    if (not f.exists())
    {
        document.replace(g::c::HA_INFORMATION, "");
        return;
    }

    QString infoBlock {m_informationBlock};
    QString customText;
    if (f.exists())
    {
        if (not f.open(QIODevice::ReadOnly))
        {
            qWarning() << "information.html exists, but reading failed";
        }
        else
        {
            customText = f.readAll();
            f.close();
        }
    }

    infoBlock.replace("{{VALUE}}", customText);
    document.replace(g::c::HA_INFORMATION, "\n"+infoBlock);
}

void WebPage::copyright(QString &document)
{
    document.replace(g::c::HA_COPYRIGHT, g::c::COPYRIGHT);
}

QString WebPage::lastDestinationItem(const QString &destination)
{
    QString result {m_lastDestinationItem};
    result.replace("{{VALUE}}", destination);
    return result;
}

QString WebPage::dailyTopDestinationItem(const QString &destination)
{
    QString result {m_dailyTopDestinationItem};
    result.replace("{{VALUE}}", destination);
    return result;
}

QString WebPage::totalTopDestinationItem(const QString &destination)
{
    QString result {m_totalTopDestinationItem};
    result.replace("{{VALUE}}", destination);
    return result;
}

QString WebPage::blockedDestinationItem(const QString &destination, const QStringList &addresses)
{
    QString result {m_blockedDestinationItemLvl1};
    result.replace("{{VALUE}}", destination);
    QString addressesItems;
    for (const auto& addr: addresses)
    {
        QString addrItem {m_blockedDestinationItemLvl2};
        addrItem.replace("{{VALUE}}", addr);
        addressesItems += addrItem;
    }
    result.replace("{{LIST}}", addressesItems);
    return result;
}

QPair<QString, QString> WebPage::bytesToHumanReadableString(quint64 bytes)
{
    QPair<QString, QString> result;

    constexpr const qint64 thresh = 1024;

    if (bytes < thresh)
    {
        result.first = QString::number(bytes);
        result.second = "B";
    }

    else if (bytes <= thresh*thresh)
    {
        result.first = QString::number(bytes/thresh);
        result.second = "KiB";
    }

    else if (bytes <= thresh*thresh*thresh)
    {
        result.first = QString::number(bytes/thresh/thresh);
        result.second = "MiB";
    }

    else if (bytes <= thresh*thresh*thresh*thresh)
    {
        result.first = QString::number(bytes/thresh/thresh/thresh);
        result.second = "GiB";
    }

    else if (bytes <= thresh*thresh*thresh*thresh*thresh)
    {
        result.first = QString::number(bytes/thresh/thresh/thresh/thresh);
        result.second = "TiB";
    }

    else if (bytes <= thresh*thresh*thresh*thresh*thresh*thresh)
    {
        result.first = QString::number(bytes/thresh/thresh/thresh/thresh/thresh);
        result.second = "PiB";
    }

    return result;
}