#include "browsertab.hpp"
#include "ui_browsertab.h"
#include "mainwindow.hpp"
#include "settingsdialog.hpp"

#include "gophermaprenderer.hpp"
#include "geminirenderer.hpp"
#include "plaintextrenderer.hpp"

#include "certificateselectiondialog.hpp"

#include "ioutil.hpp"
#include "kristall.hpp"

#include <cassert>
#include <QTabWidget>
#include <QMenu>
#include <QMessageBox>
#include <QInputDialog>
#include <QDockWidget>
#include <QImage>
#include <QPixmap>
#include <QFile>
#include <QMimeDatabase>
#include <QMimeType>
#include <QImageReader>

#include <QGraphicsPixmapItem>
#include <QGraphicsTextItem>


BrowserTab::BrowserTab(MainWindow * mainWindow) :
    QWidget(nullptr),
    ui(new Ui::BrowserTab),
    mainWindow(mainWindow),
    outline(),
    graphics_scene()
{
    ui->setupUi(this);

    connect(&web_client, &WebClient::requestComplete, this, &BrowserTab::on_requestComplete);
    connect(&web_client, &WebClient::requestFailed, this, &BrowserTab::on_requestFailed);
    connect(&web_client, &WebClient::requestProgress, this, &BrowserTab::on_requestProgress);

    connect(&gemini_client, &GeminiClient::requestComplete, this, &BrowserTab::on_requestComplete);
    connect(&gemini_client, &GeminiClient::requestProgress, this, &BrowserTab::on_requestProgress);
    connect(&gemini_client, &GeminiClient::protocolViolation, this, &BrowserTab::on_protocolViolation);
    connect(&gemini_client, &GeminiClient::inputRequired, this, &BrowserTab::on_inputRequired);
    connect(&gemini_client, &GeminiClient::redirected, this, &BrowserTab::on_redirected);
    connect(&gemini_client, &GeminiClient::temporaryFailure, this, &BrowserTab::on_temporaryFailure);
    connect(&gemini_client, &GeminiClient::permanentFailure, this, &BrowserTab::on_permanentFailure);
    connect(&gemini_client, &GeminiClient::transientCertificateRequested, this, &BrowserTab::on_transientCertificateRequested);
    connect(&gemini_client, &GeminiClient::authorisedCertificateRequested, this, &BrowserTab::on_authorisedCertificateRequested);
    connect(&gemini_client, &GeminiClient::certificateRejected, this, &BrowserTab::on_certificateRejected);
    connect(&gemini_client, &GeminiClient::networkError, this, &BrowserTab::on_networkError);

    connect(&gopher_client, &GopherClient::requestComplete, this, &BrowserTab::on_requestComplete);
    connect(&gopher_client, &GopherClient::requestFailed, this, &BrowserTab::on_requestFailed);
    connect(&gopher_client, &GopherClient::requestProgress, this, &BrowserTab::on_requestProgress);

    connect(&finger_client, &FingerClient::requestComplete, this, &BrowserTab::on_requestComplete);
    connect(&finger_client, &FingerClient::requestFailed, this, &BrowserTab::on_requestFailed);
    connect(&finger_client, &FingerClient::requestProgress, this, &BrowserTab::on_requestProgress);

    this->updateUI();

    this->ui->media_browser->setVisible(false);
    this->ui->graphics_browser->setVisible(false);
    this->ui->text_browser->setVisible(true);

    this->ui->text_browser->setContextMenuPolicy(Qt::CustomContextMenu);
}

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

void BrowserTab::navigateTo(const QUrl &url, PushToHistory mode)
{
    if(mainWindow->protocols.isSchemeSupported(url.scheme()) != ProtocolSetup::Enabled)
    {
        QMessageBox::warning(this, "Kristall", "URI scheme not supported or disabled: " + url.scheme());
        return;
    }

    this->timer.start();

    this->current_location = url;
    this->ui->url_bar->setText(url.toString(QUrl::FormattingOptions(QUrl::FullyEncoded)));

    if(not gemini_client.cancelRequest()) {
        QMessageBox::warning(this, "Kristall", "Failed to cancel running gemini request!");
        return;
    }

    if(not web_client.cancelRequest()) {
        QMessageBox::warning(this, "Kristall", "Failed to cancel running web request!");
        return;
    }

    if(not gopher_client.cancelRequest()) {
        QMessageBox::warning(this, "Kristall", "Failed to cancel running gopher request!");
        return;
    }

    if(not finger_client.cancelRequest()) {
        QMessageBox::warning(this, "Kristall", "Failed to cancel running finger request!");
        return;
    }

    this->redirection_count = 0;
    this->successfully_loaded = false;

    if(url.scheme() == "gemini")
    {
        gemini_client.startRequest(url);
    }
    else if(url.scheme() == "http" or url.scheme() == "https")
    {
        web_client.startRequest(url);
    }
    else if(url.scheme() == "gopher")
    {
        gopher_client.startRequest(url);
    }
    else if(url.scheme() == "finger")
    {
        finger_client.startRequest(url);
    }
    else if(url.scheme() == "file")
    {
        QFile file { url.path() };

        if(file.open(QFile::ReadOnly))
        {
            QMimeDatabase db;
            auto mime = db.mimeTypeForUrl(url).name();
            auto data = file.readAll();
            qDebug() << "database:" << url << mime;
            this->on_requestComplete(data, mime);
        }
        else
        {

        }
    }
    else if(url.scheme() == "about")
    {
        this->redirection_count = 0;
        if(url.path() == "blank")
        {
            this->on_requestComplete("", "text/gemini");
        }
        else if(url.path() == "favourites")
        {
            QByteArray document;

            document.append("# Favourites\n");
            document.append("\n");

            for(auto const & fav : this->mainWindow->favourites.getAll())
            {
                document.append("=> " + fav.toString().toUtf8() + "\n");
            }

            this->on_requestComplete(document, "text/gemini");
        }
        else
        {
            QFile file(QString(":/about/%1.gemini").arg(url.path()));
            if(file.open(QFile::ReadOnly))
            {
                this->on_requestComplete(file.readAll(), "text/gemini");
            }
            else
            {
                QMessageBox::warning(this, "Kristall", "Unknown location: " + url.path());
            }
        }
    }


    switch(mode)
    {
    case DontPush:
        break;

    case PushImmediate:
        pushToHistory(url);
        break;
    }

    this->updateUI();
}

void BrowserTab::navigateBack(QModelIndex history_index)
{
    auto url = history.get(history_index);

    if(url.isValid()) {
        current_history_index = history_index;
        navigateTo(url, DontPush);
    }
}

void BrowserTab::navOneBackback()
{
    navigateBack(history.oneBackward(current_history_index));
}

void BrowserTab::navOneForward()
{
    navigateBack(history.oneForward(current_history_index));
}

void BrowserTab::scrollToAnchor(QString const & anchor)
{
    qDebug() << "scroll to anchor" << anchor;
    this->ui->text_browser->scrollToAnchor(anchor);
}

void BrowserTab::reloadPage()
{
    if(current_location.isValid())
        this->navigateTo(this->current_location, DontPush);
}

void BrowserTab::toggleIsFavourite()
{
    toggleIsFavourite(not this->ui->fav_button->isChecked());
}

void BrowserTab::toggleIsFavourite(bool isFavourite)
{
    if(isFavourite) {
        this->mainWindow->favourites.add(this->current_location);
    } else {
        this->mainWindow->favourites.remove(this->current_location);
    }

    this->updateUI();
}

void BrowserTab::focusUrlBar()
{
    this->ui->url_bar->setFocus(Qt::ShortcutFocusReason);
    this->ui->url_bar->selectAll();
}

void BrowserTab::on_url_bar_returnPressed()
{
    QUrl url { this->ui->url_bar->text() };

    if(url.scheme().isEmpty()) {
        url = QUrl { "gemini://" + this->ui->url_bar->text() };
    }

    this->navigateTo(url, PushImmediate);
}

void BrowserTab::on_refresh_button_clicked()
{
    reloadPage();
}

void BrowserTab::on_requestFailed(const QString &reason)
{
    this->setErrorMessage(QString("Request failed:\n%1").arg(reason));
}

void BrowserTab::on_networkError(const QString &reason)
{
    this->setErrorMessage(QString("Network error:\n%1").arg(reason));
}

void BrowserTab::on_requestComplete(const QByteArray &data, const QString &mime)
{
    qDebug() << "Loaded" << data.length() << "bytes of type" << mime;

    this->current_mime = mime;
    this->current_buffer = data;

    this->graphics_scene.clear();
    this->ui->text_browser->setText("");

    ui->text_browser->setStyleSheet("");

    enum DocumentType { Text, Image, Media };

    DocumentType doc_type = Text;
    std::unique_ptr<QTextDocument> document;

    this->outline.clear();

    auto doc_style = mainWindow->current_style.derive(this->current_location);

    this->ui->text_browser->setStyleSheet(QString("QTextBrowser { background-color: %1; }").arg(doc_style.background_color.name()));

    bool plaintext_only = (global_settings.value("text_display").toString() == "plain");

    if(not plaintext_only and mime.startsWith("text/gemini")) {
        document = GeminiRenderer::render(
            data,
            this->current_location,
            doc_style,
            this->outline);
    }
    else if(not plaintext_only and mime.startsWith("text/gophermap")) {
        document = GophermapRenderer::render(
            data,
            this->current_location,
            doc_style);
    }
    else if(not plaintext_only and mime.startsWith("text/finger")) {
        document = PlainTextRenderer::render(data, doc_style);
    }
    else if(not plaintext_only and mime.startsWith("text/html")) {
        document = std::make_unique<QTextDocument>();

        document->setDefaultFont(doc_style.standard_font);
        document->setDefaultStyleSheet(doc_style.toStyleSheet());
        document->setDocumentMargin(doc_style.margin);
        document->setHtml(QString::fromUtf8(data));
    }
#if defined(QT_FEATURE_textmarkdownreader)
    else if(not plaintext_only and mime.startsWith("text/markdown")) {
        document = std::make_unique<QTextDocument>();
        document->setDefaultFont(doc_style.standard_font);
        document->setDefaultStyleSheet(doc_style.toStyleSheet());
        document->setDocumentMargin(doc_style.margin);
        document->setMarkdown(QString::fromUtf8(data));
    }
#endif
    else if(mime.startsWith("text/")) {
        document = PlainTextRenderer::render(data, doc_style);
    }
    else if(mime.startsWith("image/")) {
        doc_type = Image;

        QBuffer buffer;
        buffer.setData(data);

        QImageReader reader { &buffer };
        reader.setAutoTransform(true);
        reader.setAutoDetectImageFormat(true);


        QImage img;
        if(reader.read(&img))
        {
            auto pixmap = QPixmap::fromImage(img);
            this->graphics_scene.addPixmap(pixmap);
            this->graphics_scene.setSceneRect(pixmap.rect());
        }
        else
        {
            this->graphics_scene.addText(QString("Failed to load picture:\r\n%1").arg(reader.errorString()));
        }

        this->ui->graphics_browser->setScene(&graphics_scene);

        auto * invoker = new QObject();
        connect(invoker, &QObject::destroyed, [this]() {
            this->ui->graphics_browser->fitInView(graphics_scene.sceneRect(), Qt::KeepAspectRatio);
        });
        invoker->deleteLater();

        this->ui->graphics_browser->fitInView(graphics_scene.sceneRect(), Qt::KeepAspectRatio);
    }
    else if(mime.startsWith("video/") or mime.startsWith("audio/")) {
        doc_type = Media;
        this->ui->media_browser->setMedia(data, this->current_location, mime);
    }
    else {
        document = std::make_unique<QTextDocument>();
        document->setDefaultFont(doc_style.standard_font);
        document->setDefaultStyleSheet(doc_style.toStyleSheet());

        document->setPlainText(QString(R"md(You accessed an unsupported media type!

Use the *File* menu to save the file to your local disk or navigate somewhere else. I cannot display this for you. ☹

Info:
MIME Type: %1
File Size: %2
)md").arg(mime).arg(IoUtil::size_human(data.size())));
    }

    assert((document != nullptr) == (doc_type == Text));

    this->ui->text_browser->setVisible(doc_type == Text);
    this->ui->graphics_browser->setVisible(doc_type == Image);
    this->ui->media_browser->setVisible(doc_type == Media);

    this->ui->text_browser->setDocument(document.get());
    this->current_document = std::move(document);

    emit this->locationChanged(this->current_location);

    QString title = this->current_location.toString();
    emit this->titleChanged(title);

    emit this->fileLoaded(data.size(), mime, this->timer.elapsed());

    this->successfully_loaded = true;

    this->updateUI();
}

void BrowserTab::on_protocolViolation(const QString &reason)
{
    this->setErrorMessage(QString("Protocol violation:\n%1").arg(reason));
}

void BrowserTab::on_inputRequired(const QString &query)
{
    QInputDialog dialog { this };

    dialog.setInputMode(QInputDialog::TextInput);
    dialog.setLabelText(query);

    if(dialog.exec() != QDialog::Accepted) {
        setErrorMessage(QString("Site requires input:\n%1").arg(query));
        return;
    }

    QUrl new_location = current_location;
    new_location.setQuery(dialog.textValue());
    this->navigateTo(new_location, DontPush);
}

void BrowserTab::on_redirected(const QUrl &uri, bool is_permanent)
{
    if(redirection_count >= 5) {
        setErrorMessage("Too many redirections!");
        return;
    }
    else {
        if(gemini_client.startRequest(uri)) {
            redirection_count += 1;
            this->current_location = uri;
            this->ui->url_bar->setText(uri.toString());
        }
    }
}

void BrowserTab::on_temporaryFailure(TemporaryFailure reason, const QString &info)
{
    switch(reason)
    {
    case TemporaryFailure::cgi_error:
        setErrorMessage(QString("CGI Error\n%1").arg(info));
        break;
    case TemporaryFailure::slow_down:
        setErrorMessage(QString("Slow Down\n%1").arg(info));
        break;
    case TemporaryFailure::proxy_error:
        setErrorMessage(QString("Proxy Error\n%1").arg(info));
        break;
    case TemporaryFailure::unspecified:
        setErrorMessage(QString("Temporary Failure\n%1").arg(info));
        break;
    case TemporaryFailure::server_unavailable:
        setErrorMessage(QString("Server Unavailable\n%1").arg(info));
        break;
    }
}

void BrowserTab::on_permanentFailure(PermanentFailure reason, const QString &info)
{
    switch(reason)
    {
    case PermanentFailure::gone:
        setErrorMessage(QString("Gone\n%1").arg(info));
        break;
    case PermanentFailure::not_found:
        setErrorMessage(QString("Not Found\n%1").arg(info));
        break;
    case PermanentFailure::bad_request:
        setErrorMessage(QString("Bad Request\n%1").arg(info));
        break;
    case PermanentFailure::unspecified:
        setErrorMessage(QString("Permanent Failure\n%1").arg(info));
        break;
    case PermanentFailure::proxy_request_required:
        setErrorMessage(QString("Proxy Request Required\n%1").arg(info));
        break;
    }
}

void BrowserTab::on_transientCertificateRequested(const QString &reason)
{
    if(not trySetClientCertificate(reason)) {
        setErrorMessage(QString("The page requested a transient client certificate, but none was provided.\r\nOriginal query was: %1").arg(reason));
    } else {
        this->navigateTo(this->current_location, DontPush);
    }
    this->updateUI();
}

void BrowserTab::on_authorisedCertificateRequested(const QString &reason)
{
    if(not trySetClientCertificate(reason)) {
        setErrorMessage(QString("The page requested a authorized client certificate, but none was provided.\r\nOriginal query was: %1").arg(reason));
    } else {
        this->navigateTo(this->current_location, DontPush);
    }
    this->updateUI();
}

void BrowserTab::on_certificateRejected(CertificateRejection reason, const QString &info)
{
    switch(reason)
    {
    case CertificateRejection::unspecified:
        setErrorMessage(QString("Certificate Rejected\n%1").arg(info));
        break;
    case CertificateRejection::not_accepted:
        setErrorMessage(QString("Certificate not accepted\n%1").arg(info));
        break;
    case CertificateRejection::future_certificate_rejected:
        setErrorMessage(QString("Certificate is not yet valid\n%1").arg(info));
        break;
    case CertificateRejection::expired_certificate_rejected:
        setErrorMessage(QString("Certificate expired\n%1").arg(info));
        break;
    }
}

void BrowserTab::on_linkHovered(const QString &url)
{
    this->mainWindow->setUrlPreview(QUrl(url));
}

void BrowserTab::setErrorMessage(const QString &msg)
{
    this->on_requestComplete(
        QString("An error happened:\r\n%0").arg(msg).toUtf8(),
        "text/plain charset=utf-8"
    );

    this->updateUI();
}

void BrowserTab::pushToHistory(const QUrl &url)
{
    this->current_history_index = this->history.pushUrl(this->current_history_index, url);
    this->updateUI();
}

void BrowserTab::on_fav_button_clicked()
{
    toggleIsFavourite(this->ui->fav_button->isChecked());
}

#include <QDesktopServices>


void BrowserTab::on_text_browser_anchorClicked(const QUrl &url)
{
    qDebug() << url;

    QUrl real_url = url;
    if(real_url.isRelative())
        real_url = this->current_location.resolved(url);

    auto support = mainWindow->protocols.isSchemeSupported(real_url.scheme());

    if(support == ProtocolSetup::Enabled) {
        this->navigateTo(real_url, PushImmediate);
    } else {
        bool use_os_proxy = global_settings.value("use_os_scheme_handler").toBool();

        if(use_os_proxy) {
            if(not QDesktopServices::openUrl(url)) {
                QMessageBox::warning(this, "Kristall", QString("Failed to start system URL handler for\r\n%1").arg(real_url.toString()));
            }
        } else if(support == ProtocolSetup::Disabled) {
            QMessageBox::warning(this, "Kristall", QString("The requested url uses a scheme that has been disabled in the settings:\r\n%1").arg(real_url.toString()));
        } else {
            QMessageBox::warning(this, "Kristall", QString("The requested url cannot be processed by Kristall:\r\n%1").arg(real_url.toString()));
        }
    }
}

void BrowserTab::on_text_browser_highlighted(const QUrl &url)
{
    if(url.isValid()) {
        QUrl real_url = url;
        if(real_url.isRelative())
            real_url = this->current_location.resolved(url);
        this->mainWindow->setUrlPreview(real_url);
    }
    else {
        this->mainWindow->setUrlPreview(QUrl { });
    }
}

void BrowserTab::on_stop_button_clicked()
{
    gemini_client.cancelRequest();
    web_client.cancelRequest();
    gopher_client.cancelRequest();
    finger_client.cancelRequest();
}

void BrowserTab::on_requestProgress(qint64 transferred)
{
    emit this->fileLoaded(transferred, "Loading...", timer.elapsed());
}

void BrowserTab::on_back_button_clicked()
{
    navOneBackback();
}

void BrowserTab::on_forward_button_clicked()
{
    navOneForward();
}

void BrowserTab::updateUI()
{
    this->ui->back_button->setEnabled(history.oneBackward(current_history_index).isValid());
    this->ui->forward_button->setEnabled(history.oneForward(current_history_index).isValid());

    this->ui->refresh_button->setVisible(this->successfully_loaded);
    this->ui->stop_button->setVisible(not this->successfully_loaded);

    this->ui->fav_button->setEnabled(this->successfully_loaded);
    this->ui->fav_button->setChecked(this->mainWindow->favourites.contains(this->current_location));
}

bool BrowserTab::trySetClientCertificate(const QString &query)
{
    CertificateSelectionDialog dialog { this };

    dialog.setServerQuery(query);

    if(dialog.exec() != QDialog::Accepted) {
        this->gemini_client.disableClientCertificate();
        this->ui->enable_client_cert_button->setChecked(false);
        return false;
    }

    this->current_identitiy = dialog.identity();

    if(not current_identitiy.isValid()) {
        QMessageBox::warning(this, "Kristall", "Failed to generate temporary crypto-identitiy");
        this->gemini_client.disableClientCertificate();
        this->ui->enable_client_cert_button->setChecked(false);
        return false;
    }

    this->gemini_client.enableClientCertificate(this->current_identitiy);
    this->ui->enable_client_cert_button->setChecked(true);

    return true;
}

void BrowserTab::resetClientCertificate()
{
    if(this->current_identitiy.isValid() and not this->current_identitiy.is_persistent)
    {
        auto respo = QMessageBox::question(this, "Kristall", "You currently have a transient session active!\r\nIf you disable the session, you will not be able to restore it. Continue?");
        if(respo != QMessageBox::Yes) {
            this->ui->enable_client_cert_button->setChecked(true);
            return;
        }
    }

    this->gemini_client.disableClientCertificate();
    this->ui->enable_client_cert_button->setChecked(false);
}

#include <QClipboard>

void BrowserTab::on_text_browser_customContextMenuRequested(const QPoint &pos)
{
    QMenu menu;

    QString anchor = ui->text_browser->anchorAt(pos);
    if(not anchor.isEmpty()) {
        QUrl real_url { anchor };
        if(real_url.isRelative())
            real_url = this->current_location.resolved(real_url);

        connect(menu.addAction("Follow link…"), &QAction::triggered, [this,real_url]() {
            this->navigateTo(real_url, PushImmediate);
        });

        connect(menu.addAction("Open in new tab…"), &QAction::triggered, [this,real_url]() {
            mainWindow->addNewTab(false, real_url);
        });

        connect(menu.addAction("Copy link"), &QAction::triggered, [this,real_url]() {
            global_clipboard->setText(real_url.toString(QUrl::FullyEncoded));
        });

        menu.addSeparator();
    }

    connect(menu.addAction("Select all"), &QAction::triggered, [this]() {
        this->ui->text_browser->selectAll();
    });

    menu.exec(ui->text_browser->mapToGlobal(pos));
}

void BrowserTab::on_enable_client_cert_button_clicked(bool checked)
{
    if(checked) {
        trySetClientCertificate(QString{ });
    } else {
        resetClientCertificate();
    }
}