/****************************************************************************
**
** Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies).
** All rights reserved.
** Contact: Nokia Corporation (qt-info@nokia.com)
**
** This file is part of the QtDeclarative module of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:LGPL$
** No Commercial Usage
** This file contains pre-release code and may not be distributed.
** You may use this file in accordance with the terms and conditions
** contained in the Technology Preview License Agreement accompanying
** this package.
**
** GNU Lesser General Public License Usage
** Alternatively, this file may be used under the terms of the GNU Lesser
** 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.
**
**
**
**
**
**
**
**
** $QT_END_LICENSE$
**
****************************************************************************/

#include "qdeclarativecontext.h"
#include "private/qdeclarativecontext_p.h"

#include "private/qdeclarativeexpression_p.h"
#include "private/qdeclarativeengine_p.h"
#include "qdeclarativeengine.h"
#include "private/qdeclarativecompiledbindings_p.h"
#include "qdeclarativeinfo.h"
#include "private/qdeclarativeglobalscriptclass_p.h"

#include <qscriptengine.h>
#include <QtCore/qvarlengtharray.h>
#include <QtCore/qdebug.h>

#include <private/qscriptdeclarativeclass_p.h>

QT_BEGIN_NAMESPACE

QDeclarativeContextPrivate::QDeclarativeContextPrivate()
: data(0), notifyIndex(-1)
{
}

/*!
    \class QDeclarativeContext
    \since 4.7
    \brief The QDeclarativeContext class defines a context within a QML engine.
    \mainclass

    Contexts allow data to be exposed to the QML components instantiated by the
    QML engine.

    Each QDeclarativeContext contains a set of properties, distinct from its QObject 
    properties, that allow data to be explicitly bound to a context by name.  The 
    context properties are defined and updated by calling 
    QDeclarativeContext::setContextProperty().  The following example shows a Qt model 
    being bound to a context and then accessed from a QML file.

    \code
    QDeclarativeEngine engine;
    QDeclarativeContext *context = new QDeclarativeContext(engine.rootContext());
    context->setContextProperty("myModel", modelData);

    QDeclarativeComponent component(&engine, "ListView { model=myModel }");
    component.create(context);
    \endcode

    To simplify binding and maintaining larger data sets, a context object can be set
    on a QDeclarativeContext.  All the properties of the context object are available
    by name in the context, as though they were all individually added through calls
    to QDeclarativeContext::setContextProperty().  Changes to the property's values are 
    detected through the property's notify signal.  Setting a context object is both 
    faster and easier than manually adding and maintaing context property values.

    The following example has the same effect as the previous one, but it uses a context
    object.

    \code
    class MyDataSet : ... {
        ...
        Q_PROPERTY(QAbstractItemModel *myModel READ model NOTIFY modelChanged)
        ...
    };

    MyDataSet *myDataSet = new MyDataSet;
    QDeclarativeEngine engine;
    QDeclarativeContext *context = new QDeclarativeContext(engine.rootContext());
    context->setContextObject(myDataSet);

    QDeclarativeComponent component(&engine, "ListView { model=myModel }");
    component.create(context);
    \endcode

    All properties added explicitly by QDeclarativeContext::setContextProperty() take 
    precedence over context object's properties.

    Contexts form a hierarchy.  The root of this heirarchy is the QDeclarativeEngine's
    \l {QDeclarativeEngine::rootContext()}{root context}.  A component instance can 
    access the data in its own context, as well as all its ancestor contexts.  Data
    can be made available to all instances by modifying the 
    \l {QDeclarativeEngine::rootContext()}{root context}.

    The following example defines two contexts - \c context1 and \c context2.  The
    second context overrides the "b" context property inherited from the first with a
    new value.

    \code
    QDeclarativeEngine engine;
    QDeclarativeContext *context1 = new QDeclarativeContext(engine.rootContext());
    QDeclarativeContext *context2 = new QDeclarativeContext(context1);

    context1->setContextProperty("a", 12);
    context1->setContextProperty("b", 12);

    context2->setContextProperty("b", 15);
    \endcode

    While QML objects instantiated in a context are not strictly owned by that 
    context, their bindings are.  If a context is destroyed, the property bindings of 
    outstanding QML objects will stop evaluating.
*/

/*! \internal */
QDeclarativeContext::QDeclarativeContext(QDeclarativeEngine *e, bool)
: QObject(*(new QDeclarativeContextPrivate))
{
    Q_D(QDeclarativeContext);
    d->data = new QDeclarativeContextData(this);

    d->data->engine = e;
}

/*!
    Create a new QDeclarativeContext as a child of \a engine's root context, and the
    QObject \a parent.
*/
QDeclarativeContext::QDeclarativeContext(QDeclarativeEngine *engine, QObject *parent)
: QObject(*(new QDeclarativeContextPrivate), parent)
{
    Q_D(QDeclarativeContext);
    d->data = new QDeclarativeContextData(this);

    d->data->setParent(engine?QDeclarativeContextData::get(engine->rootContext()):0);
}

/*!
    Create a new QDeclarativeContext with the given \a parentContext, and the
    QObject \a parent.
*/
QDeclarativeContext::QDeclarativeContext(QDeclarativeContext *parentContext, QObject *parent)
: QObject(*(new QDeclarativeContextPrivate), parent)
{
    Q_D(QDeclarativeContext);
    d->data = new QDeclarativeContextData(this);

    d->data->setParent(parentContext?QDeclarativeContextData::get(parentContext):0);
}

/*!
    \internal
*/
QDeclarativeContext::QDeclarativeContext(QDeclarativeContextData *data)
: QObject(*(new QDeclarativeContextPrivate), 0)
{
    Q_D(QDeclarativeContext);
    d->data = data;
}

/*!
    Destroys the QDeclarativeContext.

    Any expressions, or sub-contexts dependent on this context will be
    invalidated, but not destroyed (unless they are parented to the QDeclarativeContext
    object).
 */
QDeclarativeContext::~QDeclarativeContext()
{
    Q_D(QDeclarativeContext);

    if (!d->data->isInternal)
        d->data->destroy();
}

bool QDeclarativeContext::isValid() const
{
    Q_D(const QDeclarativeContext);
    return d->data && d->data->isValid();
}

/*!
    Return the context's QDeclarativeEngine, or 0 if the context has no QDeclarativeEngine or the
    QDeclarativeEngine was destroyed.
*/
QDeclarativeEngine *QDeclarativeContext::engine() const
{
    Q_D(const QDeclarativeContext);
    return d->data->engine;
}

/*!
    Return the context's parent QDeclarativeContext, or 0 if this context has no
    parent or if the parent has been destroyed.
*/
QDeclarativeContext *QDeclarativeContext::parentContext() const
{
    Q_D(const QDeclarativeContext);
    return d->data->parent?d->data->parent->asQDeclarativeContext():0;
}

/*!
    Return the context object, or 0 if there is no context object.
*/
QObject *QDeclarativeContext::contextObject() const
{
    Q_D(const QDeclarativeContext);
    return d->data->contextObject;
}

/*!
    Set the context \a object.
*/
void QDeclarativeContext::setContextObject(QObject *object)
{
    Q_D(QDeclarativeContext);

    QDeclarativeContextData *data = d->data;

    if (data->isInternal) {
        qWarning("QDeclarativeContext: Cannot set context object for internal context.");
        return;
    }

    if (!isValid()) {
        qWarning("QDeclarativeContext: Cannot set context object on invalid context.");
        return;
    }

    data->contextObject = object;
}

/*!
    Set a the \a value of the \a name property on this context.
*/
void QDeclarativeContext::setContextProperty(const QString &name, const QVariant &value)
{
    Q_D(QDeclarativeContext);
    if (d->notifyIndex == -1)
        d->notifyIndex = this->metaObject()->methodCount();

    QDeclarativeContextData *data = d->data;

    if (data->isInternal) {
        qWarning("QDeclarativeContext: Cannot set property on internal context.");
        return;
    }

    if (!isValid()) {
        qWarning("QDeclarativeContext: Cannot set property on invalid context.");
        return;
    }

    if (data->engine) {
        bool ok;
        QObject *o = QDeclarativeEnginePrivate::get(data->engine)->toQObject(value, &ok);
        if (ok) {
            setContextProperty(name, o);
            return;
        }
    }

    if (!data->propertyNames) data->propertyNames = new QDeclarativeIntegerCache(data->engine);

    int idx = data->propertyNames->value(name);
    if (idx == -1) {
        data->propertyNames->add(name, data->idValueCount + d->propertyValues.count());
        d->propertyValues.append(value);

        data->refreshExpressions();
    } else {
        d->propertyValues[idx] = value;
        QMetaObject::activate(this, idx + d->notifyIndex, 0);
    }
}

/*!
    Set the \a value of the \a name property on this context.

    QDeclarativeContext does \bold not take ownership of \a value.
*/
void QDeclarativeContext::setContextProperty(const QString &name, QObject *value)
{
    Q_D(QDeclarativeContext);
    if (d->notifyIndex == -1)
        d->notifyIndex = this->metaObject()->methodCount();

    QDeclarativeContextData *data = d->data;

    if (data->isInternal) {
        qWarning("QDeclarativeContext: Cannot set property on internal context.");
        return;
    }

    if (!isValid()) {
        qWarning("QDeclarativeContext: Cannot set property on invalid context.");
        return;
    }

    if (!data->propertyNames) data->propertyNames = new QDeclarativeIntegerCache(data->engine);
    int idx = data->propertyNames->value(name);

    if (idx == -1) {
        data->propertyNames->add(name, data->idValueCount + d->propertyValues.count());
        d->propertyValues.append(QVariant::fromValue(value));

        data->refreshExpressions();
    } else {
        d->propertyValues[idx] = QVariant::fromValue(value);
        QMetaObject::activate(this, idx + d->notifyIndex, 0);
    }
}

/*!
  Returns the value of the \a name property for this context
  as a QVariant.
 */
QVariant QDeclarativeContext::contextProperty(const QString &name) const
{
    Q_D(const QDeclarativeContext);
    QVariant value;
    int idx = -1;

    QDeclarativeContextData *data = d->data;

    if (data->propertyNames)
        idx = data->propertyNames->value(name);

    if (idx == -1) {
        QByteArray utf8Name = name.toUtf8();
        if (data->contextObject) {
            QObject *obj = data->contextObject;
            QDeclarativePropertyCache::Data local;
            QDeclarativePropertyCache::Data *property = 
                QDeclarativePropertyCache::property(data->engine, obj, name, local);

            if (property) value = obj->metaObject()->property(property->coreIndex).read(obj);
        }
        if (!value.isValid() && parentContext())
            value = parentContext()->contextProperty(name);
    } else {
        if (idx >= d->propertyValues.count())
            value = QVariant::fromValue(data->idValues[idx - d->propertyValues.count()].data());
        else
            value = d->propertyValues[idx];
    }

    return value;
}

/*!
    Resolves the URL \a src relative to the URL of the
    containing component.

    \sa QDeclarativeEngine::baseUrl(), setBaseUrl()
*/
QUrl QDeclarativeContext::resolvedUrl(const QUrl &src)
{
    Q_D(QDeclarativeContext);
    return d->data->resolvedUrl(src);
}

QUrl QDeclarativeContextData::resolvedUrl(const QUrl &src)
{
    QDeclarativeContextData *ctxt = this;

    if (src.isRelative() && !src.isEmpty()) {
        if (ctxt) {
            while(ctxt) {
                if(ctxt->url.isValid())
                    break;
                else
                    ctxt = ctxt->parent;
            }

            if (ctxt)
                return ctxt->url.resolved(src);
            else if (engine)
                return engine->baseUrl().resolved(src);
        }
        return QUrl();
    } else {
        return src;
    }
}


/*!
    Explicitly sets the url resolvedUrl() will use for relative references to \a baseUrl.

    Calling this function will override the url of the containing
    component used by default.

    \sa resolvedUrl()
*/
void QDeclarativeContext::setBaseUrl(const QUrl &baseUrl)
{
    Q_D(QDeclarativeContext);

    d->data->url = baseUrl;
}

/*!
    Returns the base url of the component, or the containing component
    if none is set.
*/
QUrl QDeclarativeContext::baseUrl() const
{
    Q_D(const QDeclarativeContext);
    const QDeclarativeContextData* data = d->data;
    while (data && data->url.isEmpty()) 
        data = data->parent;

    if (data)
        return data->url;
    else
        return QUrl();
}

int QDeclarativeContextPrivate::context_count(QDeclarativeListProperty<QObject> *prop)
{
    QDeclarativeContext *context = static_cast<QDeclarativeContext*>(prop->object);
    QDeclarativeContextPrivate *d = QDeclarativeContextPrivate::get(context);
    int contextProperty = (int)(intptr_t)prop->data;

    if (d->propertyValues.at(contextProperty).userType() != qMetaTypeId<QList<QObject*> >()) {
        return 0;
    } else {
        return ((const QList<QObject> *)d->propertyValues.at(contextProperty).constData())->count();
    }
}

QObject *QDeclarativeContextPrivate::context_at(QDeclarativeListProperty<QObject> *prop, int index)
{
    QDeclarativeContext *context = static_cast<QDeclarativeContext*>(prop->object);
    QDeclarativeContextPrivate *d = QDeclarativeContextPrivate::get(context);
    int contextProperty = (int)(intptr_t)prop->data;

    if (d->propertyValues.at(contextProperty).userType() != qMetaTypeId<QList<QObject*> >()) {
        return 0;
    } else {
        return ((const QList<QObject*> *)d->propertyValues.at(contextProperty).constData())->at(index);
    }
}


QDeclarativeContextData::QDeclarativeContextData()
: parent(0), engine(0), isInternal(false), publicContext(0), propertyNames(0), contextObject(0),
  imports(0), childContexts(0), nextChild(0), prevChild(0), expressions(0), contextObjects(0),
  contextGuards(0), idValues(0), idValueCount(0), optimizedBindings(0), linkedContext(0)
{
}

QDeclarativeContextData::QDeclarativeContextData(QDeclarativeContext *ctxt)
: parent(0), engine(0), isInternal(false), publicContext(ctxt), propertyNames(0), contextObject(0),
  imports(0), childContexts(0), nextChild(0), prevChild(0), expressions(0), contextObjects(0),
  contextGuards(0), idValues(0), idValueCount(0), optimizedBindings(0), linkedContext(0)
{
}

void QDeclarativeContextData::destroy()
{
    if (linkedContext) 
        linkedContext->destroy();

    if (prevChild) {
        *prevChild = nextChild;
        if (nextChild) nextChild->prevChild = prevChild;
        nextChild = 0;
        prevChild = 0;
    }
    
    QDeclarativeContextData *child = childContexts;
    while (child) {
        QDeclarativeContextData *next = child->nextChild;

        child->invalidateEngines();
        child->parent = 0;
        child->nextChild = 0;
        child->prevChild = 0;

        child = next;
    }
    childContexts = 0;

    QDeclarativeAbstractExpression *expression = expressions;
    while (expression) {
        QDeclarativeAbstractExpression *nextExpression = expression->m_nextExpression;

        expression->m_context = 0;
        expression->m_prevExpression = 0;
        expression->m_nextExpression = 0;

        expression = nextExpression;
    }
    expressions = 0;

    while (contextObjects) {
        QDeclarativeDeclarativeData *co = contextObjects;
        contextObjects = contextObjects->nextContextObject;

        co->context = 0;
        co->outerContext = 0;
        co->nextContextObject = 0;
        co->prevContextObject = 0;
    }

    QDeclarativeGuardedContextData *contextGuard = contextGuards;
    while (contextGuard) {
        QDeclarativeGuardedContextData *next = contextGuard->m_next;
        contextGuard->m_next = 0;
        contextGuard->m_prev = 0;
        contextGuard->m_contextData = 0;
        contextGuard = next;
    }
    contextGuards = 0;

    if (propertyNames)
        propertyNames->release();

    if (imports)
        imports->release();

    if (optimizedBindings)
        optimizedBindings->release();

    delete [] idValues;

    if (isInternal)
        delete publicContext;

    delete this;
}

void QDeclarativeContextData::setParent(QDeclarativeContextData *p)
{
    if (p) {
        parent = p;
        engine = p->engine;
        nextChild = p->childContexts;
        if (nextChild) nextChild->prevChild = &nextChild;
        prevChild = &p->childContexts;
        p->childContexts = this;
    }
}

void QDeclarativeContextData::invalidateEngines()
{
    if (!engine)
        return;
    engine = 0;

    QDeclarativeContextData *child = childContexts;
    while (child) {
        child->invalidateEngines();
        child = child->nextChild;
    }
}

/* 
Refreshes all expressions that could possibly depend on this context.  Refreshing flushes all 
context-tree dependent caches in the expressions, and should occur every time the context tree 
 *structure* (not values) changes.
*/
void QDeclarativeContextData::refreshExpressions()
{
    QDeclarativeContextData *child = childContexts;
    while (child) {
        child->refreshExpressions();
        child = child->nextChild;
    }

    QDeclarativeAbstractExpression *expression = expressions;
    while (expression) {
        expression->refresh();
        expression = expression->m_nextExpression;
    }
}

void QDeclarativeContextData::addObject(QObject *o)
{
    QDeclarativeDeclarativeData *data = QDeclarativeDeclarativeData::get(o, true);

    Q_ASSERT(data->context == 0);

    data->context = this;
    data->outerContext = this;

    data->nextContextObject = contextObjects;
    if (data->nextContextObject) 
        data->nextContextObject->prevContextObject = &data->nextContextObject;
    data->prevContextObject = &contextObjects;
    contextObjects = data;
}

void QDeclarativeContextData::addImportedScript(const QDeclarativeParser::Object::ScriptBlock &script)
{
    if (!engine) 
        return;

    Q_ASSERT(script.codes.count() == 1);

    QDeclarativeEnginePrivate *enginePriv = QDeclarativeEnginePrivate::get(engine);
    QScriptEngine *scriptEngine = QDeclarativeEnginePrivate::getScriptEngine(engine);

    const QString &code = script.codes.at(0);
    const QString &url = script.files.at(0);
    const QDeclarativeParser::Object::ScriptBlock::Pragmas &pragmas = script.pragmas.at(0);

    Q_ASSERT(!url.isEmpty());

    if (pragmas & QDeclarativeParser::Object::ScriptBlock::Shared) {

        QHash<QString, QScriptValue>::Iterator iter = enginePriv->m_sharedScriptImports.find(url);
        if (iter == enginePriv->m_sharedScriptImports.end()) {
            QScriptContext *scriptContext = QScriptDeclarativeClass::pushCleanContext(scriptEngine);

            scriptContext->pushScope(enginePriv->contextClass->newContext(0, 0));
            scriptContext->pushScope(enginePriv->globalClass->globalObject());
        
            QScriptValue scope = scriptEngine->newObject();
            scriptContext->setActivationObject(scope);
            scriptContext->pushScope(scope);

            scriptEngine->evaluate(code, url, 1);

            if (scriptEngine->hasUncaughtException()) {
                QDeclarativeError error;
                QDeclarativeExpressionPrivate::exceptionToError(scriptEngine, error);
                qWarning().nospace() << qPrintable(error.toString());
            }

            scriptEngine->popContext();

            iter = enginePriv->m_sharedScriptImports.insert(url, scope);
        }

        importedScripts.append(*iter);

    } else {

        QScriptContext *scriptContext = QScriptDeclarativeClass::pushCleanContext(scriptEngine);

        scriptContext->pushScope(enginePriv->contextClass->newContext(this, 0));
        scriptContext->pushScope(enginePriv->globalClass->globalObject());
        
        QScriptValue scope = scriptEngine->newObject();
        scriptContext->setActivationObject(scope);
        scriptContext->pushScope(scope);

        scriptEngine->evaluate(code, url, 1);

        if (scriptEngine->hasUncaughtException()) {
            QDeclarativeError error;
            QDeclarativeExpressionPrivate::exceptionToError(scriptEngine, error);
            qWarning().nospace() << qPrintable(error.toString());
        }

        scriptEngine->popContext();

        importedScripts.append(scope);

    }
}

void QDeclarativeContextData::addScript(const QDeclarativeParser::Object::ScriptBlock &script, 
                                        QObject *scopeObject)
{
    if (!engine) 
        return;

    QDeclarativeEnginePrivate *enginePriv = QDeclarativeEnginePrivate::get(engine);
    QScriptEngine *scriptEngine = QDeclarativeEnginePrivate::getScriptEngine(engine);

    QScriptContext *scriptContext = QScriptDeclarativeClass::pushCleanContext(scriptEngine);

    scriptContext->pushScope(enginePriv->contextClass->newContext(this, scopeObject));
    scriptContext->pushScope(enginePriv->globalClass->globalObject());
    
    QScriptValue scope = scriptEngine->newObject();
    scriptContext->setActivationObject(scope);
    scriptContext->pushScope(scope);

    for (int ii = 0; ii < script.codes.count(); ++ii) {
        scriptEngine->evaluate(script.codes.at(ii), script.files.at(ii), script.lineNumbers.at(ii));

        if (scriptEngine->hasUncaughtException()) {
            QDeclarativeError error;
            QDeclarativeExpressionPrivate::exceptionToError(scriptEngine, error);
            qWarning().nospace() << qPrintable(error.toString());
        }
    }

    scriptEngine->popContext();

    scripts.append(scope);
}

void QDeclarativeContextData::setIdProperty(int idx, QObject *obj)
{
    idValues[idx] = obj;
    idValues[idx].context = this;
}

void QDeclarativeContextData::setIdPropertyData(QDeclarativeIntegerCache *data)
{
    Q_ASSERT(!propertyNames);
    propertyNames = data;
    propertyNames->addref();

    idValueCount = data->count();
    idValues = new ContextGuard[idValueCount];
}

QString QDeclarativeContextData::findObjectId(const QObject *obj) const
{
    if (!idValues || !propertyNames)
        return QString();

    for (int i=0; i<idValueCount; i++) {
        if (idValues[i] == obj)
            return propertyNames->findId(i);
    }    

    if (linkedContext)
        return linkedContext->findObjectId(obj);
    return QString();
}

QDeclarativeContext *QDeclarativeContextData::asQDeclarativeContext()
{
    if (!publicContext) 
        publicContext = new QDeclarativeContext(this);
    return publicContext;
}

QDeclarativeContextPrivate *QDeclarativeContextData::asQDeclarativeContextPrivate()
{
    return QDeclarativeContextPrivate::get(asQDeclarativeContext());
}

QT_END_NAMESPACE