/****************************************************************************
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** Copyright (C) 2012 Nokia Corporation and/or its subsidiary(-ies).
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** This file is part of the QtQml module of the Qt Toolkit.
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** Alternatively, this file may be used under the terms of the GNU General
** Public License version 3.0 as published by the Free Software Foundation
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** file. Please review the following information to ensure the GNU General
** Public License version 3.0 requirements will be met:
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****************************************************************************/

#include "qqmlboundsignal_p.h"

#include <private/qmetaobjectbuilder_p.h>
#include "qqmlengine_p.h"
#include "qqmlexpression_p.h"
#include "qqmlcontext_p.h"
#include "qqmlmetatype_p.h"
#include "qqml.h"
#include "qqmlcontext.h"
#include "qqmlglobal_p.h"
#include <private/qqmlprofilerservice_p.h>
#include <private/qv8debugservice_p.h>

#include <QtCore/qstringbuilder.h>
#include <QtCore/qdebug.h>

Q_DECLARE_METATYPE(QJSValue)

QT_BEGIN_NAMESPACE

class QQmlBoundSignalParameters : public QObject
{
Q_OBJECT
public:
    QQmlBoundSignalParameters(const QMetaMethod &, QObject * = 0);
    ~QQmlBoundSignalParameters();

    void setValues(void **);
    void clearValues();

private:
    friend class MetaObject;
    int metaCall(QMetaObject::Call, int _id, void **);
    struct MetaObject : public QAbstractDynamicMetaObject {
        MetaObject(QQmlBoundSignalParameters *b)
            : parent(b) {}

        int metaCall(QMetaObject::Call c, int id, void **a) { 
            return parent->metaCall(c, id, a);
        }
        QQmlBoundSignalParameters *parent;
    };

    int *types;
    void **values;
    QMetaObject *myMetaObject;
};

static int evaluateIdx = -1;

QQmlAbstractBoundSignal::QQmlAbstractBoundSignal()
: m_prevSignal(0), m_nextSignal(0)
{
}

QQmlAbstractBoundSignal::~QQmlAbstractBoundSignal()
{
    if (m_prevSignal) {
        *m_prevSignal = m_nextSignal;
        if (m_nextSignal) m_nextSignal->m_prevSignal = m_prevSignal;
        m_prevSignal = 0;
        m_nextSignal = 0;
    }
}

void QQmlAbstractBoundSignal::addToObject()
{
    Q_ASSERT(!m_prevSignal);
    QObject *obj = object();
    Q_ASSERT(obj);

    QQmlData *data = QQmlData::get(obj, true);

    m_nextSignal = data->signalHandlers;
    if (m_nextSignal) m_nextSignal->m_prevSignal = &m_nextSignal;
    m_prevSignal = &data->signalHandlers;
    data->signalHandlers = this;
}

QQmlBoundSignal::QQmlBoundSignal(QObject *scope, const QMetaMethod &signal,
                               QObject *owner)
: m_expression(0), m_signal(signal), m_paramsValid(false), m_isEvaluating(false), m_params(0), m_owner(owner)
{
    // This is thread safe.  Although it may be updated by two threads, they
    // will both set it to the same value - so the worst thing that can happen
    // is that they both do the work to figure it out.  Boo hoo.
    if (evaluateIdx == -1) evaluateIdx = metaObject()->methodCount();

    QQmlPropertyPrivate::connect(scope, m_signal.methodIndex(), this, evaluateIdx);
}

QQmlBoundSignal::~QQmlBoundSignal()
{
    delete m_expression;
    m_expression = 0;
}

int QQmlBoundSignal::index() const 
{ 
    return m_signal.methodIndex();
}

/*!
    Returns the signal expression.
*/
QQmlExpression *QQmlBoundSignal::expression() const
{
    return m_expression;
}

/*!
    Sets the signal expression to \a e.  Returns the current signal expression,
    or null if there is no signal expression.

    The QQmlBoundSignal instance takes ownership of \a e.  The caller is 
    assumes ownership of the returned QQmlExpression.
*/
QQmlExpression *QQmlBoundSignal::setExpression(QQmlExpression *e)
{
    QQmlExpression *rv = m_expression;
    m_expression = e;
    if (m_expression) m_expression->setNotifyOnValueChanged(false);
    return rv;
}

int QQmlBoundSignal::qt_metacall(QMetaObject::Call c, int id, void **a)
{
    if (c == QMetaObject::InvokeMetaMethod && id == evaluateIdx) {
        if (!m_expression)
            return -1;

        if (QQmlDebugService::isDebuggingEnabled())
            QV8DebugService::instance()->signalEmitted(QString::fromAscii(m_signal.signature()));

        QQmlHandlingSignalProfiler prof(m_signal, m_expression);

        m_isEvaluating = true;
        if (!m_paramsValid) {
            if (!m_signal.parameterTypes().isEmpty())
                m_params = new QQmlBoundSignalParameters(m_signal, this);
            m_paramsValid = true;
        }

        if (m_params) m_params->setValues(a);
        if (m_expression && m_expression->engine()) {
            QQmlExpressionPrivate::get(m_expression)->value(m_params);
            if (m_expression && m_expression->hasError())
                QQmlEnginePrivate::warning(m_expression->engine(), m_expression->error());
        }
        if (m_params) m_params->clearValues();
        m_isEvaluating = false;
        return -1;
    } else {
        return QObject::qt_metacall(c, id, a);
    }
}

QQmlBoundSignalParameters::QQmlBoundSignalParameters(const QMetaMethod &method, 
                                                                     QObject *parent)
: QObject(parent), types(0), values(0)
{
    MetaObject *mo = new MetaObject(this);

    // ### Optimize!
    QMetaObjectBuilder mob;
    mob.setSuperClass(&QQmlBoundSignalParameters::staticMetaObject);
    mob.setClassName("QQmlBoundSignalParameters");

    QList<QByteArray> paramTypes = method.parameterTypes();
    QList<QByteArray> paramNames = method.parameterNames();
    types = new int[paramTypes.count()];
    for (int ii = 0; ii < paramTypes.count(); ++ii) {
        const QByteArray &type = paramTypes.at(ii);
        const QByteArray &name = paramNames.at(ii);

        if (name.isEmpty() || type.isEmpty()) {
            types[ii] = 0;
            continue;
        }

        QVariant::Type t = (QVariant::Type)QMetaType::type(type.constData());
        if (QQmlMetaType::isQObject(t)) {
            types[ii] = QMetaType::QObjectStar;
            QMetaPropertyBuilder prop = mob.addProperty(name, "QObject*");
            prop.setWritable(false);
        } else {
            QByteArray propType = type;
            QMetaType::TypeFlags flags = QMetaType::typeFlags(t);
            if (flags & QMetaType::IsEnumeration) {
                t = QVariant::Int;
                propType = "int";
            } else if (t == QVariant::Invalid ||
                       (t >= QVariant::UserType && !(flags & QMetaType::PointerToQObject) &&
                        t != qMetaTypeId<QJSValue>())) {
                //the UserType clause is to catch registered QFlags
                QByteArray scope;
                QByteArray name;
                int scopeIdx = propType.lastIndexOf("::");
                if (scopeIdx != -1) {
                    scope = propType.left(scopeIdx);
                    name = propType.mid(scopeIdx + 2);
                } else {
                    name = propType;
                }
                const QMetaObject *meta;
                if (scope == "Qt")
                    meta = &QObject::staticQtMetaObject;
                else
                    meta = static_cast<QQmlBoundSignal*>(parent)->object()->metaObject();
                for (int i = meta->enumeratorCount() - 1; i >= 0; --i) {
                    QMetaEnum m = meta->enumerator(i);
                    if ((m.name() == name) && (scope.isEmpty() || (m.scope() == scope))) {
                        t = QVariant::Int;
                        propType = "int";
                        break;
                    }
                }
            }
            types[ii] = t;
            QMetaPropertyBuilder prop = mob.addProperty(name, propType);
            prop.setWritable(false);
        }
    }
    myMetaObject = mob.toMetaObject();
    *static_cast<QMetaObject *>(mo) = *myMetaObject;

    d_ptr->metaObject = mo;
}

QQmlBoundSignalParameters::~QQmlBoundSignalParameters()
{
    delete [] types;
    free(myMetaObject);
}

void QQmlBoundSignalParameters::setValues(void **v)
{
    values = v;
}

void QQmlBoundSignalParameters::clearValues()
{
    values = 0;
}

int QQmlBoundSignalParameters::metaCall(QMetaObject::Call c, int id, void **a)
{
    if (!values)
        return -1;

    if (c == QMetaObject::ReadProperty && id >= 1) {
        int t = types[id - 1];
        void *p = a[0];
        QMetaType::destruct(t, p);
        QMetaType::construct(t, p, values[id]);
        return -1;
    } else {
        return qt_metacall(c, id, a);
    }
}

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

QQmlBoundSignalNoParams::QQmlBoundSignalNoParams(QObject *scope, const QMetaMethod &signal,
                               QObject *owner)
: m_expression(0), m_owner(owner), m_index(signal.methodIndex()), m_isEvaluating(false)
{
    callback = &subscriptionCallback;
    QQmlNotifierEndpoint::connect(scope, m_index);
}

QQmlBoundSignalNoParams::~QQmlBoundSignalNoParams()
{
    delete m_expression;
    m_expression = 0;
}

int QQmlBoundSignalNoParams::index() const
{
    return m_index;
}

/*!
    Returns the signal expression.
*/
QQmlExpression *QQmlBoundSignalNoParams::expression() const
{
    return m_expression;
}

/*!
    Sets the signal expression to \a e.  Returns the current signal expression,
    or null if there is no signal expression.

    The QQmlBoundSignalNoParams instance takes ownership of \a e.  The caller is
    assumes ownership of the returned QQmlExpression.
*/
QQmlExpression *QQmlBoundSignalNoParams::setExpression(QQmlExpression *e)
{
    QQmlExpression *rv = m_expression;
    m_expression = e;
    if (m_expression) m_expression->setNotifyOnValueChanged(false);
    return rv;
}

void QQmlBoundSignalNoParams::subscriptionCallback(QQmlNotifierEndpoint *e)
{
    QQmlBoundSignalNoParams *s = static_cast<QQmlBoundSignalNoParams*>(e);
    if (!s->m_expression)
        return;

    if (QQmlDebugService::isDebuggingEnabled())
        QV8DebugService::instance()->signalEmitted(QString::fromAscii(s->m_owner->metaObject()->method(s->m_index).signature()));

    QQmlHandlingSignalProfiler prof(s->m_owner, s->m_index, s->m_expression);

    s->m_isEvaluating = true;

    if (s->m_expression && s->m_expression->engine()) {
        QQmlExpressionPrivate::get(s->m_expression)->value();
        if (s->m_expression && s->m_expression->hasError())
            QQmlEnginePrivate::warning(s->m_expression->engine(), s->m_expression->error());
    }
    s->m_isEvaluating = false;
}

QT_END_NAMESPACE

#include <qqmlboundsignal.moc>