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#include "jsexpander.h"

#include "corejsextensions.h"

#include <utils/macroexpander.h>
#include <utils/qtcassert.h>

#include <QCoreApplication>
#include <QDebug>
#include <QJSEngine>

namespace Core {

namespace Internal {

class JsExpanderPrivate {
public:
    QJSEngine m_engine;
};

} // namespace Internal

static Internal::JsExpanderPrivate *d;

void JsExpander::registerQObjectForJs(const QString &name, QObject *obj)
{
    QJSValue jsObj = d->m_engine.newQObject(obj);
    d->m_engine.globalObject().setProperty(name, jsObj);
}

QString JsExpander::evaluate(const QString &expression, QString *errorMessage)
{
    QJSValue value = d->m_engine.evaluate(expression);
    if (value.isError()) {
        const QString msg = QCoreApplication::translate("Core::JsExpander", "Error in \"%1\": %2")
                .arg(expression, value.toString());
        if (errorMessage)
            *errorMessage = msg;
        return QString();
    }
    // Try to convert to bool, be that an int or whatever.
    if (value.isBool())
        return value.toString();
    if (value.isNumber())
        return QString::number(value.toNumber());
    if (value.isString())
        return value.toString();
    QString msg = QCoreApplication::translate("Core::JsExpander",
                                              "Cannot convert result of \"%1\" to string.").arg(expression);
    if (errorMessage)
        *errorMessage = msg;
    return QString();
}

JsExpander::JsExpander()
{
    d = new Internal::JsExpanderPrivate;
    Utils::globalMacroExpander()->registerPrefix("JS",
        QCoreApplication::translate("Core::JsExpander",
                                    "Evaluate simple Javascript statements.<br>"
                                    "The statements may not contain '{' nor '}' characters."),
        [this](QString in) -> QString {
            QString errorMessage;
            QString result = JsExpander::evaluate(in, &errorMessage);
            if (!errorMessage.isEmpty()) {
                qWarning() << errorMessage;
                return errorMessage;
            } else {
                return result;
            }
        });

    registerQObjectForJs(QLatin1String("Util"), new Internal::UtilsJsExtension);
}

JsExpander::~JsExpander()
{
    delete d;
    d = 0;
}

} // namespace Core