/***************************************************************************
 *   Copyright (C) 2005-2007 by Joris Guisson                              *
 *   joris.guisson@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 2 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, write to the                         *
 *   Free Software Foundation, Inc.,                                       *
 *   51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.          *
 ***************************************************************************/

#include "upnpdescriptionparser.h"

#include <QFile>
#include <QStack>
#include <QStringRef>
#include <QXmlStreamReader>

#include <util/fileops.h>
#include <util/log.h>
#include "upnprouter.h"

using namespace bt;

namespace bt
{

class XMLContentHandler
{
    enum Status {
        TOPLEVEL, ROOT, DEVICE, SERVICE, FIELD, OTHER
    };

    QString tmp;
    UPnPRouter* router;
    UPnPService curr_service;
    QStack<Status> status_stack;
public:
    XMLContentHandler(UPnPRouter* router);
    ~XMLContentHandler();

    bool parse(const QByteArray& data);

    bool startDocument();
    bool endDocument();
    bool startElement(const QStringRef& namespaceUri, const QStringRef& localName,
                      const QStringRef& qName, const QXmlStreamAttributes& atts);
    bool endElement(const QStringRef& namespaceUri, const QStringRef& localName,
                    const QStringRef& qName);
    bool characters(const QStringRef& chars);

    bool interestingDeviceField(const QStringRef& name);
    bool interestingServiceField(const QStringRef& name);
};


UPnPDescriptionParser::UPnPDescriptionParser()
{}


UPnPDescriptionParser::~UPnPDescriptionParser()
{}

bool UPnPDescriptionParser::parse(const QString & file, UPnPRouter* router)
{
    QFile fptr(file);
    if (!fptr.open(QIODevice::ReadOnly))
        return false;

    QByteArray data = fptr.readAll();
    XMLContentHandler chandler(router);

    const bool ret = chandler.parse(data);

    if (!ret) {
        Out(SYS_PNP | LOG_IMPORTANT) << "Error parsing XML" << endl;
        return false;
    }
    return true;
}

bool UPnPDescriptionParser::parse(const QByteArray & data, UPnPRouter* router)
{
    XMLContentHandler chandler(router);

    const bool ret = chandler.parse(data);


    if (!ret) {
        Out(SYS_PNP | LOG_IMPORTANT) << "Error parsing XML" << endl;
        return false;
    }
    return true;
}

/////////////////////////////////////////////////////////////////////////////////


XMLContentHandler::XMLContentHandler(UPnPRouter* router) : router(router)
{}

XMLContentHandler::~XMLContentHandler()
{}

bool XMLContentHandler::parse(const QByteArray& data)
{
    QXmlStreamReader reader(data);

    while (!reader.atEnd()) {
        reader.readNext();
        if (reader.hasError())
            return false;

        switch (reader.tokenType()) {
        case QXmlStreamReader::StartDocument:
            if (!startDocument()) {
                return false;
            }
            break;
        case QXmlStreamReader::EndDocument:
            if (!endDocument()) {
                return false;
            }
            break;
        case QXmlStreamReader::StartElement:
            if (!startElement(reader.namespaceUri(), reader.name(),
                              reader.qualifiedName(), reader.attributes())) {
                return false;
            }
            break;
        case QXmlStreamReader::EndElement:
            if (!endElement(reader.namespaceUri(), reader.name(),
                            reader.qualifiedName())) {
                return false;
            }
            break;
        case QXmlStreamReader::Characters:
            if (!reader.isWhitespace() && !reader.text().trimmed().isEmpty()) {
                if (!characters(reader.text()))
                    return false;
            }
            break;
        default:
            break;
        }
    }

    if (!reader.isEndDocument())
        return false;

    return true;
}

bool XMLContentHandler::startDocument()
{
    status_stack.push(TOPLEVEL);
    return true;
}

bool XMLContentHandler::endDocument()
{
    status_stack.pop();
    return true;
}

bool XMLContentHandler::interestingDeviceField(const QStringRef& name)
{
    return name == "friendlyName" || name == "manufacturer" || name == "modelDescription" ||
           name == "modelName" || name == "modelNumber";
}


bool XMLContentHandler::interestingServiceField(const QStringRef& name)
{
    return name == "serviceType" || name == "serviceId" || name == "SCPDURL" ||
           name == "controlURL" || name == "eventSubURL";
}

bool XMLContentHandler::startElement(const QStringRef& namespaceUri, const QStringRef& localName,
                                     const QStringRef& qName, const QXmlStreamAttributes& atts)
{
    Q_UNUSED(namespaceUri)
    Q_UNUSED(qName)
    Q_UNUSED(atts)

    tmp = "";
    switch (status_stack.top()) {
    case TOPLEVEL:
        // from toplevel we can only go to root
        if (localName == "root")
            status_stack.push(ROOT);
        else
            return false;
        break;
    case ROOT:
        // from the root we can go to device or specVersion
        // we are not interested in the specVersion
        if (localName == "device")
            status_stack.push(DEVICE);
        else
            status_stack.push(OTHER);
        break;
    case DEVICE:
        // see if it is a field we are interested in
        if (interestingDeviceField(localName))
            status_stack.push(FIELD);
        else
            status_stack.push(OTHER);
        break;
    case SERVICE:
        if (interestingServiceField(localName))
            status_stack.push(FIELD);
        else
            status_stack.push(OTHER);
        break;
    case OTHER:
        if (localName == "service")
            status_stack.push(SERVICE);
        else if (localName == "device")
            status_stack.push(DEVICE);
        else
            status_stack.push(OTHER);
        break;
    case FIELD:
        break;
    }
    return true;
}

bool XMLContentHandler::endElement(const QStringRef& namespaceUri, const QStringRef& localName,
                                   const QStringRef& qName)
{
    Q_UNUSED(namespaceUri)
    Q_UNUSED(qName)

    switch (status_stack.top()) {
    case FIELD:
        // we have a field so set it
        status_stack.pop();
        if (status_stack.top() == DEVICE) {
            // if we are in a device
            router->getDescription().setProperty(localName.toString(), tmp);
        } else if (status_stack.top() == SERVICE) {
            // set a property of a service
            curr_service.setProperty(localName.toString(), tmp);
        }
        break;
    case SERVICE:
        // add the service
        router->addService(curr_service);
        curr_service.clear();
        // pop the stack
        status_stack.pop();
        break;
    default:
        status_stack.pop();
        break;
    }

    // reset tmp
    tmp = "";
    return true;
}

bool XMLContentHandler::characters(const QStringRef& chars)
{
    tmp.append(chars);
    return true;
}

}
