/****************************************************************************
 **
 ** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
 ** Contact: Qt Software Information (qt-info@nokia.com)
 **
 ** This file is part of the WebClient project on Trolltech Labs.
 **
 ** This file may be used under the terms of the GNU General Public
 ** License version 2.0 or 3.0 as published by the Free Software Foundation
 ** and appearing in the file LICENSE.GPL included in the packaging of
 ** this file.  Please review the following information to ensure GNU
 ** General Public Licensing requirements will be met:
 ** http://www.fsf.org/licensing/licenses/info/GPLv2.html and
 ** http://www.gnu.org/copyleft/gpl.html.
 **
 ** If you are unsure which license is appropriate for your use, please
 ** contact the sales department at qt-sales@nokia.com.
 **
 ** This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
 ** WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 **
 ****************************************************************************/

#include "eventqueue.h"
#include "webclient.h"
#include <QImage>

void encodeText(QString &text)
{
    // encode "breakout" characters
    text.replace("&", "&amp;");
    text.replace("<", "&lt;");
    text.replace(">", "&gt;");
    text.replace("'", "&apos;");
    text.replace('"', "&quot;");
    text.replace("/", "&#47");

    // white-list for safe tags
    text.replace("&lt;b&gt;", "<b>");
    text.replace("&lt;&#47b&gt;", "</b>");
}

QString widgetGetText(QWidget *widget)
{
    QString text;

    if (QLineEdit *lineEdit = qobject_cast<QLineEdit *>(widget)) {
        text = lineEdit->text();
    } else if (QTextEdit *textEdit = qobject_cast<QTextEdit *>(widget)) {
        text = textEdit->toPlainText();
    } else if (QPushButton *pushButton = qobject_cast<QPushButton*>(widget)) {
        text = pushButton->text();
    } else if (QLabel *label = qobject_cast<QLabel*>(widget)) {
        text = label->text();
    } else {
        text = "unsupported text widget";;
    }

    encodeText(text);

    return text;
}

EventQueue::EventQueue(Session *session)
:m_session(session)
{
    reset();
}

void EventQueue::setSession(Session *session)
{
    m_session = session;
    reset();
}

void EventQueue::reset()
{
    DEBUG << "reset";
    images.clear();
    geometries.clear();
}

void EventQueue::handleRequest(HttpRequest *request, HttpResponse *response)
{
//    DEBUG << "handle request" << request->path();
    const QByteArray path = request->path();

    if (path == "/content") {
        DEBUG << "content";
        response->setBody(queueToByteArray());
    } else if (path == "/idle") {
        DEBUG << "idle";
        response->setBody(queueToByteArray());

    // If the part starts with "/json" then the rest of the string is an json-encoded
    // string object.
    } else if (path.startsWith("/json")) {
        QByteArray jsonText = path.mid(5); // remove "/json"
        handleJsonRequest(jsonText, response);
    }
}

void EventQueue::handleJsonRequest(QByteArray jsonText, HttpResponse *response)
{
    // replace symbols that can't be a part of the url text.
    jsonText.replace("%7B", "{");
    jsonText.replace("%7D", "}");
    jsonText.replace("%22", "\"");

    DEBUG << "json request" << jsonText;
    json_object* jsonRequest = json_tokener_parse(jsonText.data());
    if (!jsonRequest)
        return;
    json_object* type = json_object_object_get(jsonRequest, "type");

    QByteArray typeText = json_object_get_string(type);

    if (typeText == "img") {
        handleImageRequest(jsonRequest, response);
    } else if (typeText == "img-static") {
        handleStaticImageRequest(jsonRequest, response);
    }
    json_object_put(jsonRequest); //free
}

void EventQueue::handleImageRequest(json_object* jsonRequest, HttpResponse *response)
{
    json_object* idObject = json_object_object_get(jsonRequest, "id");
    if (!idObject)
        return;

    const quintptr id = json_object_get_int(idObject);
    DEBUG << "id" << this << id << images.value(id).size();
 //   if (staticCompressedImages.contains(id))
 //       qFatal("serving dynamic image for static widdget");

    // Save server memory and CPU time by storing images in the png
    // format after the first serve. The browser could request
    // the image again, for example if the user hits refresh.
    QByteArray pngImage;
    QImage uncompressedImage = images.value(id);
    if (uncompressedImage.isNull()== false) {
        images.remove(id);

        QBuffer buffer(&pngImage);
        buffer.open(QIODevice::WriteOnly);
        QImageWriter writer(&buffer, "png");
        writer.write(uncompressedImage);

        compressedImages.insert(id, pngImage);
    }

    if (pngImage.isEmpty()) {
        pngImage = compressedImages.value(id);
    }

    response->setBody(pngImage);
    response->setContentType("image/png");
}

void EventQueue::handleStaticImageRequest(json_object* jsonRequest, HttpResponse *response)
{
    json_object* imageHashObject = json_object_object_get(jsonRequest, "imagehash");
    DEBUG << "handleStaticImageRequest" << imageHashObject;
    if (!imageHashObject)
        return;

    const quintptr imageHash = json_object_get_int(imageHashObject);
    DEBUG << "imagehash" << this << imageHash;

    quintptr imageid = staticImageHashToWidgetId.value(imageHash);
    QByteArray pngImage = staticCompressedImages.value(imageid);
    DEBUG << imageid << pngImage.count();
    response->setNeverExpires();
    response->setBody(pngImage);
    response->setContentType("image/png");
}

void EventQueue::addUpdateEvent(quintptr id, const QImage &image, QRect updateRect)
{
    DEBUG << "addUpdateEvent" << this << id << image.size();
    images.insert(id, image);
    addEvent(id, EventEntry::Update);
}
void EventQueue::addStaticUpdateEvent(quintptr id, uint hash, const QByteArray &pngImage)
{
    DEBUG << "addStaticUpdateEvent" << this << hash << pngImage.size();
    staticCompressedImages.insert(id, pngImage);
    staticImageHashToWidgetId.insert(hash, id);
    staticWidgetIdToImageHash.insert(id, hash);
    addEvent(id, EventEntry::StaticUpdate);
}

void EventQueue::addStaticUpdateEvent(quintptr id)
{
    DEBUG << "addStaticUpdateEvent" << this << id;
    // assert staticCompressedImages.conrains(id);
    addEvent(id, EventEntry::StaticUpdate);
}

void EventQueue::addGeometryEvent(quintptr id, QRect globalGeometry)
{
    if (geometries[id] == globalGeometry) {
        return;
    }
    geometries[id] = globalGeometry;
    addEvent(id, EventEntry::Geometry);
}

void EventQueue::addParentChangeEvent(quintptr id)
{
//    DEBUG << "parentchanged";
    addEvent(id, EventEntry::ParentChange);
}

void EventQueue::addEvent(quintptr id, EventEntry::Type type)
{
    EventEntry entry(id, type);

    if (events.contains(entry)) {
//        DEBUG << "event already in queue";
        return;
    }

    events.enqueue(entry);
//    DEBUG << json_object_to_json_string(toJson(entry));

    if (m_session)
        m_session->contentAvailable();
}

QByteArray EventQueue::queueToByteArray()
{
    if (events.isEmpty())
        return QByteArray();

    json_object *array = json_object_new_array();
    while (events.isEmpty() == false) {
        json_object_array_add(array, toJson(events.dequeue()));
    }

    QByteArray text(json_object_to_json_string(array));

    DEBUG << "sending event text" << text;
    // json_free(array);

   return text;

}

json_object *EventQueue::toJson(const EventEntry &event) const
{
    switch(event.type)
    {
    case EventEntry::Update:
        return jsonUpdateEvent(event);
    case EventEntry::StaticUpdate:
        return jsonStaticUpdateEvent(event);
    case EventEntry::Show:
        return jsonShowEvent(event);
    case EventEntry::ShowLineEdit:
        return jsonShowLineEditEvent(event);
    case EventEntry::Hide:
        return jsonHideEvent(event);
    case EventEntry::Geometry:
        return jsonGeometryEvent(event);
    case EventEntry::ParentChange:
        return jsonParentChangeEvent(event);
    case EventEntry::TextUpdate:
        return jsonTextUpdateEvent(event);
    default:
        return json_object_new_object();
    break;
    }
}

json_object *EventQueue::jsonShowEvent(const EventEntry &event) const
{
    struct json_object *obj = json_object_new_object();
    QWidget *widget = (QWidget *)event.id;
    json_object_object_add(obj, "type", json_object_new_string("show"));
    json_object_object_add(obj, "id", json_object_new_int(event.id));
    json_object_object_add(obj, "widgetType", toJsonWidgetType(widget));
    json_object_object_add(obj, "className",
        json_object_new_string(const_cast<char *>(widget->metaObject()->className())));
    json_object_object_add(obj, "objectName",
        json_object_new_string(widget->objectName().toAscii().data()));
    return obj;
}

json_object *EventQueue::jsonShowLineEditEvent(const EventEntry &event) const
{
    DEBUG << "### Show line edit";
    struct json_object *obj = json_object_new_object();
    json_object_object_add(obj, "type", json_object_new_string("showLineEdit"));
    json_object_object_add(obj, "id", json_object_new_int(event.id));
    return obj;
}


json_object *EventQueue::jsonHideEvent(const EventEntry &event) const
{
    struct json_object *obj = json_object_new_object();
    json_object_object_add(obj, "type", json_object_new_string("hide"));
    json_object_object_add(obj, "id", json_object_new_int(event.id));
    json_object_object_add(obj, "widgetType", toJsonWidgetType((QWidget *)event.id));
    return obj;
}

json_object *EventQueue::jsonUpdateEvent(const EventEntry &event) const
{
    struct json_object *obj = json_object_new_object();
    json_object_object_add(obj, "type", json_object_new_string("update"));
    json_object_object_add(obj, "id", json_object_new_int(event.id));
    json_object_object_add(obj, "widgetType", toJsonWidgetType((QWidget *)event.id));
    return obj;
}

json_object *EventQueue::jsonStaticUpdateEvent(const EventEntry &event) const
{
    struct json_object *obj = json_object_new_object();
    json_object_object_add(obj, "type", json_object_new_string("update"));
    json_object_object_add(obj, "id", json_object_new_int(event.id));
    json_object_object_add(obj, "imagehash",
        json_object_new_string(QByteArray::number(staticWidgetIdToImageHash.value(event.id)).data()));
    json_object_object_add(obj, "widgetType", toJsonWidgetType((QWidget *)event.id));
    return obj;
}


json_object *EventQueue::jsonGeometryEvent(const EventEntry &event) const
{
    struct json_object *obj = json_object_new_object();
    json_object_object_add(obj, "type", json_object_new_string("geometry"));
    json_object_object_add(obj, "id", json_object_new_int(event.id));
    json_object_object_add(obj, "widgetType", toJsonWidgetType((QWidget *)event.id));

    QRect geometry = geometries.value(event.id);
    json_object_object_add(obj, "x", json_object_new_int(geometry.x()));
    json_object_object_add(obj, "y", json_object_new_int(geometry.y()));
    json_object_object_add(obj, "w", json_object_new_int(geometry.width()));
    json_object_object_add(obj, "h", json_object_new_int(geometry.height()));

    return obj;
}

json_object *EventQueue::jsonParentChangeEvent(const EventEntry &event) const
{
//    DEBUG << "parentchanged send";
    QWidget *parent = ((QWidget *)event.id)->parentWidget();
    struct json_object *obj = json_object_new_object();
    json_object_object_add(obj, "type", json_object_new_string("parentChange"));
    json_object_object_add(obj, "id", json_object_new_int(event.id));
    json_object_object_add(obj, "widgetType", toJsonWidgetType(parent));
    json_object_object_add(obj, "parent", json_object_new_int((int)(parent)));

    return obj;
}

json_object *EventQueue::jsonTextUpdateEvent(const EventEntry &event) const
{
    struct json_object *obj = json_object_new_object();
    json_object_object_add(obj, "type", json_object_new_string("textUpdate"));
    json_object_object_add(obj, "id", json_object_new_int(event.id));
    json_object_object_add(obj, "widgetType", toJsonWidgetType((QWidget *)event.id));
    json_object_object_add(obj, "text", json_object_new_string(widgetGetText((QWidget *)event.id).toLocal8Bit().data()));
    return obj;
}

json_object *EventQueue::toJsonWidgetType(QWidget *widget) const
{
    if (!widget || m_session && m_session->m_server->shouldSkipUpdate(widget->metaObject()->className()))
        return json_object_new_string("skippedwidget");
    if (qobject_cast<QLineEdit *>(widget))
        return json_object_new_string("lineedit");
    if (qobject_cast<QTextEdit *>(widget))
        return json_object_new_string("textedit");
    if (qobject_cast<QLabel *>(widget))
        return json_object_new_string("label");
    if (qobject_cast<QMdiSubWindow *>(widget))
        return json_object_new_string("midisubwindow");
    if (qobject_cast<QPushButton *>(widget))
        return json_object_new_string("pusbutton");
    else
        return json_object_new_string("generic");
}

QByteArray EventQueue::pngCompress(const QImage &image)
{
    QByteArray pngImage;
    QBuffer buffer(&pngImage);
    buffer.open(QIODevice::WriteOnly);
    QImageWriter writer(&buffer, "png");
    writer.write(image);
    return pngImage;
}