#include "vupdater.h"

#include <QtWidgets>
#include <QJsonDocument>
#include <QJsonObject>
#include <QTimer>
#include <QWebEngineView>

#include "vconfigmanager.h"
#include "vdownloader.h"
#include "vmarkdownconverter.h"
#include "utils/vutils.h"
#include "vnote.h"

extern VConfigManager *g_config;

VUpdater::VUpdater(QWidget *p_parent)
    : QDialog(p_parent)
{
    setupUI();
}

void VUpdater::setupUI()
{
    QImage img(":/resources/icons/vnote_update.svg");
    QSize imgSize(128, 128);
    QLabel *imgLabel = new QLabel();
    imgLabel->setPixmap(QPixmap::fromImage(img.scaled(imgSize)));

    m_versionLabel = new QLabel(tr("Current Version: v%1")
                                  .arg(g_config->c_version));

    m_proLabel = new QLabel(tr("Checking for updates..."));
    m_proLabel->setOpenExternalLinks(true);
    m_proBar = new QProgressBar();
    m_proBar->setTextVisible(false);

    m_descriptionWV = VUtils::getWebEngineView();
    m_descriptionWV->setContextMenuPolicy(Qt::NoContextMenu);
    m_descriptionWV->setHtml(VUtils::generateSimpleHtmlTemplate(VNote::s_sloganTemplate),
                             QUrl("qrc:/resources"));

    m_btnBox = new QDialogButtonBox(QDialogButtonBox::Ok);
    m_btnBox->button(QDialogButtonBox::Ok)->setProperty("SpecialBtn", true);
    connect(m_btnBox, &QDialogButtonBox::accepted, this, &QDialog::accept);

    QVBoxLayout *verLayout = new QVBoxLayout();
    verLayout->addStretch();
    verLayout->addWidget(m_versionLabel);
    verLayout->addStretch();
    verLayout->addWidget(m_proLabel);
    verLayout->addWidget(m_proBar);

    QHBoxLayout *topLayout = new QHBoxLayout();
    topLayout->addWidget(imgLabel);
    topLayout->addLayout(verLayout);
    topLayout->addStretch();

    QVBoxLayout *mainLayout = new QVBoxLayout();
    mainLayout->addLayout(topLayout);
    mainLayout->addWidget(m_descriptionWV, 1);
    mainLayout->addWidget(m_btnBox);

    m_proLabel->hide();
    m_proBar->hide();

    m_descriptionWV->setMaximumSize(600, 400);

    setLayout(mainLayout);
    mainLayout->setSizeConstraint(QLayout::SetFixedSize);
    setWindowTitle(tr("VNote Update"));
}

void VUpdater::showEvent(QShowEvent *p_event)
{
    QDialog::showEvent(p_event);

    QTimer *timer = new QTimer(this);
    timer->setSingleShot(true);
    timer->setInterval(1000);
    connect(timer, &QTimer::timeout,
            this, [this]() {
                this->checkUpdates();
            });

    timer->start();
}

void VUpdater::checkUpdates()
{
    // Change UI.
    m_proLabel->setText(tr("Checking for updates..."));
    m_proLabel->show();

    m_proBar->setEnabled(true);
    m_proBar->setMinimum(0);
    m_proBar->setMaximum(100);
    m_proBar->reset();
    m_proBar->show();

    QString url("https://api.github.com/repos/tamlok/vnote/releases/latest");
    VDownloader *downloader = new VDownloader(this);
    connect(downloader, &VDownloader::downloadFinished,
            this, &VUpdater::parseResult);
    downloader->download(url);

    m_proBar->setValue(20);
}

// Return if @p_latestVersion is newer than p_curVersion.
// They are both in format xx.xx.xx.xx
bool isNewerVersion(const QString &p_curVersion, const QString &p_latestVersion)
{
    QStringList curList = p_curVersion.split('.', QString::SkipEmptyParts);
    QStringList latestList = p_latestVersion.split('.', QString::SkipEmptyParts);

    int i = 0;
    for (; i < curList.size() && i < latestList.size(); ++i) {
        int a = curList[i].toInt();
        int b = latestList[i].toInt();

        if (a > b) {
            return false;
        } else if (a < b) {
            return true;
        }
    }


    if (i < curList.size()) {
        // 1.2.1 vs 1.2
        return false;
    } else if (i < latestList.size()) {
        // 1.2 vs 1.2.1
        return true;
    } else {
        // 1.2 vs 1.2
        return false;
    }
}

void VUpdater::parseResult(const QByteArray &p_data)
{
    m_proBar->setValue(40);
    QJsonDocument jsonDoc = QJsonDocument::fromJson(p_data);
    QJsonObject json = jsonDoc.object();

    if (jsonDoc.isNull() || json.empty()) {
        m_proBar->setEnabled(false);
        m_proLabel->setText(tr(":( Fail to check for updates.\n"
                               "Please try it later."));

        return;
    }

    m_proBar->setValue(100);

    QString tag = json["tag_name"].toString();
    if (tag.startsWith('v') && tag.size() > 3) {
        tag = tag.right(tag.size() - 1);
    }

    QString releaseName = json["name"].toString();
    QString releaseUrl = json["html_url"].toString();
    QString body = json["body"].toString();

    m_versionLabel->setText(tr("Current Version: v%1\nLatest Version: v%2")
                              .arg(g_config->c_version).arg(tag));
    if (isNewerVersion(g_config->c_version, tag)) {
        m_proLabel->setText(tr("<span style=\"font-weight: bold;\">Updates Available!</span><br/>"
                               "Please visit <a href=\"%1\">Github Releases</a> to download the latest version.")
                              .arg(releaseUrl));
    } else {
        m_proLabel->setText(tr("VNote is already the latest version."));
    }

    QString mdText = "# " + releaseName + "\n" + body;
    VMarkdownConverter mdConverter;
    QString toc;
    QString html = mdConverter.generateHtml(mdText,
                                            g_config->getMarkdownExtensions(),
                                            toc);
    html = VUtils::generateSimpleHtmlTemplate(html);
    m_descriptionWV->setHtml(html, QUrl("qrc:/resources"));
    m_proBar->hide();
}