/****************************************************************************
**
** Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies).
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** Contact: Nokia Corporation (qt-info@nokia.com)
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** This file is part of the QtDeclarative module of the Qt Toolkit.
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** No Commercial Usage
** This file contains pre-release code and may not be distributed.
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** contained in the Technology Preview License Agreement accompanying
** this package.
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** GNU Lesser General Public License Usage
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** General Public License version 2.1 as published by the Free Software
** Foundation and appearing in the file LICENSE.LGPL included in the
** packaging of this file.  Please review the following information to
** ensure the GNU Lesser General Public License version 2.1 requirements
** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
**
** In addition, as a special exception, Nokia gives you certain additional
** rights.  These rights are described in the Nokia Qt LGPL Exception
** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
**
** If you have questions regarding the use of this file, please contact
** Nokia at qt-info@nokia.com.
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** $QT_END_LICENSE$
**
****************************************************************************/

#include "qdeclarativeinclude_p.h"

#include <QtScript/qscriptengine.h>
#include <QtNetwork/qnetworkrequest.h>
#include <QtNetwork/qnetworkreply.h>
#include <QtCore/qfile.h>

#include <private/qdeclarativeengine_p.h>
#include <private/qdeclarativeglobalscriptclass_p.h>

QT_BEGIN_NAMESPACE

QDeclarativeInclude::QDeclarativeInclude(const QUrl &url, 
                                                       QDeclarativeEngine *engine, 
                                                       QScriptContext *ctxt)
: QObject(engine), m_engine(engine), m_network(0), m_reply(0), m_url(url), m_redirectCount(0)
{
    QDeclarativeEnginePrivate *ep = QDeclarativeEnginePrivate::get(engine);
    m_context = ep->contextClass->contextFromValue(QScriptDeclarativeClass::scopeChainValue(ctxt, -3));

    m_scope[0] = QScriptDeclarativeClass::scopeChainValue(ctxt, -4);
    m_scope[1] = QScriptDeclarativeClass::scopeChainValue(ctxt, -5);

    m_scriptEngine = QDeclarativeEnginePrivate::getScriptEngine(engine);
    m_network = QDeclarativeScriptEngine::get(m_scriptEngine)->networkAccessManager();

    m_result = resultValue(m_scriptEngine);

    QNetworkRequest request;
    request.setUrl(url);

    m_reply = m_network->get(request);
    QObject::connect(m_reply, SIGNAL(finished()), this, SLOT(finished()));
}

QDeclarativeInclude::~QDeclarativeInclude()
{
    delete m_reply;
}

QScriptValue QDeclarativeInclude::resultValue(QScriptEngine *engine, Status status)
{
    QScriptValue result = engine->newObject();
    result.setProperty(QLatin1String("OK"), QScriptValue(engine, Ok));
    result.setProperty(QLatin1String("LOADING"), QScriptValue(engine, Loading));
    result.setProperty(QLatin1String("NETWORK_ERROR"), QScriptValue(engine, NetworkError));
    result.setProperty(QLatin1String("EXCEPTION"), QScriptValue(engine, Exception));

    result.setProperty(QLatin1String("status"), QScriptValue(engine, status));
    return result;
}

QScriptValue QDeclarativeInclude::result() const
{
    return m_result;
}

void QDeclarativeInclude::setCallback(const QScriptValue &c)
{
    m_callback = c;
}

QScriptValue QDeclarativeInclude::callback() const
{
    return m_callback;
}

#define INCLUDE_MAXIMUM_REDIRECT_RECURSION 15
void QDeclarativeInclude::finished()
{
    m_redirectCount++;

    if (m_redirectCount < INCLUDE_MAXIMUM_REDIRECT_RECURSION) {
        QVariant redirect = m_reply->attribute(QNetworkRequest::RedirectionTargetAttribute);
        if (redirect.isValid()) {
            m_url = m_url.resolved(redirect.toUrl());
            delete m_reply; 
            
            QNetworkRequest request;
            request.setUrl(m_url);

            m_reply = m_network->get(request);
            QObject::connect(m_reply, SIGNAL(finished()), this, SLOT(finished()));
            return;
        }
    }

    if (m_reply->error() == QNetworkReply::NoError) {
        QDeclarativeEnginePrivate *ep = QDeclarativeEnginePrivate::get(m_engine);

        QByteArray data = m_reply->readAll();

        QString code = QString::fromUtf8(data);

        QString urlString = m_url.toString();
        QScriptContext *scriptContext = QScriptDeclarativeClass::pushCleanContext(m_scriptEngine);
        scriptContext->pushScope(ep->contextClass->newUrlContext(m_context, 0, urlString));
        scriptContext->pushScope(m_scope[0]);

        scriptContext->pushScope(m_scope[1]);
        scriptContext->setActivationObject(m_scope[1]);
        QDeclarativeScriptParser::extractPragmas(code);

        m_scriptEngine->evaluate(code, urlString, 1);

        m_scriptEngine->popContext();

        if (m_scriptEngine->hasUncaughtException()) {
            m_result.setProperty(QLatin1String("status"), QScriptValue(m_scriptEngine, Exception));
            m_result.setProperty(QLatin1String("exception"), m_scriptEngine->uncaughtException());
            m_scriptEngine->clearExceptions();
        } else {
            m_result.setProperty(QLatin1String("status"), QScriptValue(m_scriptEngine, Ok));
        }
    } else {
        m_result.setProperty(QLatin1String("status"), QScriptValue(m_scriptEngine, NetworkError));
    }

    callback(m_scriptEngine, m_callback, m_result);

    disconnect();
    deleteLater();
}

void QDeclarativeInclude::callback(QScriptEngine *engine, QScriptValue &callback, QScriptValue &status)
{
    if (callback.isValid()) {
        QScriptValue args = engine->newArray(1);
        args.setProperty(0, status);
        callback.call(QScriptValue(), args);
    }
}

/*!
\qmlmethod object Qt::include(string url, jsobject callback)

Include another JavaScript file.  This method can only be used from within JavaScript files, 
and not regular QML files.

Qt.include() returns an object that describes the status of the operation.  The object has
a single property, \c {status} that is set to one of the following values:

\table
\header \o Symbol \o Value \o Description
\row \o result.OK \o 0 \o The include completed successfully.
\row \o result.LOADING \o 1 \o Data is being loaded from the network.
\row \o result.NETWORK_ERROR \o 2 \o A network error occurred while fetching the url.
\row \o result.EXCEPTION \o 3 \o A JavaScript exception occurred while executing the included code.
An additional \c exception property will be set in this case.
\endtable

The return object's properties will be updated as the operation progresses.

If provided, \a callback is invoked when the operation completes.  The callback is passed
the same object as is returned from the Qt.include() call.
*/
QScriptValue QDeclarativeInclude::include(QScriptContext *ctxt, QScriptEngine *engine)
{
    if (ctxt->argumentCount() == 0)
        return engine->undefinedValue();

    QDeclarativeEnginePrivate *ep = QDeclarativeEnginePrivate::get(engine);

    QUrl contextUrl = ep->contextClass->urlFromValue(QScriptDeclarativeClass::scopeChainValue(ctxt, -3));
    if (contextUrl.isEmpty()) 
        return ctxt->throwError(QLatin1String("Qt.include(): Can only be called from JavaScript files"));

    QString urlString = ctxt->argument(0).toString();
    QUrl url(urlString);
    if (url.isRelative()) {
        url = QUrl(contextUrl).resolved(url);
        urlString = url.toString();
    }

    QString localFile = QDeclarativeEnginePrivate::urlToLocalFileOrQrc(url);

    QScriptValue func = ctxt->argument(1);
    if (!func.isFunction())
        func = QScriptValue();

    QScriptValue result;
    if (localFile.isEmpty()) {
        QDeclarativeInclude *i = 
            new QDeclarativeInclude(url, QDeclarativeEnginePrivate::getEngine(engine), ctxt);

        if (func.isValid())
            i->setCallback(func);

        result = i->result();
    } else {

        QFile f(localFile);
        if (f.open(QIODevice::ReadOnly)) {
            QByteArray data = f.readAll();
            QString code = QString::fromUtf8(data);

            QDeclarativeContextData *context = 
                ep->contextClass->contextFromValue(QScriptDeclarativeClass::scopeChainValue(ctxt, -3));

            QScriptContext *scriptContext = QScriptDeclarativeClass::pushCleanContext(engine);
            scriptContext->pushScope(ep->contextClass->newUrlContext(context, 0, urlString));
            scriptContext->pushScope(ep->globalClass->staticGlobalObject());
            QScriptValue scope = QScriptDeclarativeClass::scopeChainValue(ctxt, -5);
            scriptContext->pushScope(scope);
            scriptContext->setActivationObject(scope);
            QDeclarativeScriptParser::extractPragmas(code);

            engine->evaluate(code, urlString, 1);

            engine->popContext();

            if (engine->hasUncaughtException()) {
                result = resultValue(engine, Exception);
                result.setProperty(QLatin1String("exception"), engine->uncaughtException());
                engine->clearExceptions();
            } else {
                result = resultValue(engine, Ok);
            }
            callback(engine, func, result);
        } else {
            result = resultValue(engine, NetworkError);
            callback(engine, func, result);
        }
    }

    return result;
}

QScriptValue QDeclarativeInclude::worker_include(QScriptContext *ctxt, QScriptEngine *engine)
{
    if (ctxt->argumentCount() == 0)
        return engine->undefinedValue();

    QString urlString = ctxt->argument(0).toString();
    QUrl url(ctxt->argument(0).toString());
    if (url.isRelative()) {
        QString contextUrl = QScriptDeclarativeClass::scopeChainValue(ctxt, -3).data().toString();
        Q_ASSERT(!contextUrl.isEmpty());

        url = QUrl(contextUrl).resolved(url);
        urlString = url.toString();
    }

    QString localFile = QDeclarativeEnginePrivate::urlToLocalFileOrQrc(url);

    QScriptValue func = ctxt->argument(1);
    if (!func.isFunction())
        func = QScriptValue();

    QScriptValue result;
    if (!localFile.isEmpty()) {

        QFile f(localFile);
        if (f.open(QIODevice::ReadOnly)) {
            QByteArray data = f.readAll();
            QString code = QString::fromUtf8(data);

            QScriptContext *scriptContext = QScriptDeclarativeClass::pushCleanContext(engine);
            QScriptValue urlContext = engine->newObject();
            urlContext.setData(QScriptValue(engine, urlString));
            scriptContext->pushScope(urlContext);

            QScriptValue scope = QScriptDeclarativeClass::scopeChainValue(ctxt, -4);
            scriptContext->pushScope(scope);
            scriptContext->setActivationObject(scope);
            QDeclarativeScriptParser::extractPragmas(code);

            engine->evaluate(code, urlString, 1);

            engine->popContext();

            if (engine->hasUncaughtException()) {
                result = resultValue(engine, Exception);
                result.setProperty(QLatin1String("exception"), engine->uncaughtException());
                engine->clearExceptions();
            } else {
                result = resultValue(engine, Ok);
            }
            callback(engine, func, result);
        } else {
            result = resultValue(engine, NetworkError);
            callback(engine, func, result);
        }
    }

    return result;
}

QT_END_NAMESPACE