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** This file is part of Qbs.
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** packaging of this file. Please review the following information to
** ensure the GNU Lesser General Public License version 3 requirements
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** Alternatively, this file may be used under the terms of the GNU
** General Public License version 2.0 or (at your option) the GNU General
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****************************************************************************/

#include "settingsrepresentation.h"

#include "jsliterals.h"

#include <language/scriptengine.h>
#include <logging/logger.h>

namespace qbs {

QString settingsValueToRepresentation(const QVariant &value)
{
    return toJSLiteral(settingsValueToVariant(value));
}

static QVariant variantFromString(const QString &str, bool &ok)
{
    // ### use Qt5's JSON reader at some point.
    class DummyLogSink : public ILogSink {
        void doPrintMessage(LoggerLevel, const QString &, const QString &) override { }
    } logSink;
    Internal::Logger logger(&logSink);

    const auto engine = Internal::ScriptEngine::create(logger, {});
    Internal::ScopedJsValue sv(
                engine->context(),
                engine->evaluate(Internal::JsValueOwner::Caller,
                                 QLatin1String("(function(){return ") + str
                                 + QLatin1String(";})()")));
    ok = !engine->checkForJsError({});
    return Internal::getJsVariant(engine->context(), sv);
}

QVariant representationToSettingsValue(const QString &representation)
{
    const QVariant v = representationToVariant(representation);
    switch (static_cast<QMetaType::Type>(v.userType())) {
    // Work around QSettings losing type information when storing integer types.
    case QMetaType::Bool:
    case QMetaType::Char:
    case QMetaType::Int:
    case QMetaType::Long:
    case QMetaType::LongLong:
    case QMetaType::UChar:
    case QMetaType::UInt:
    case QMetaType::ULong:
    case QMetaType::ULongLong:
        return QVariantHash({std::make_pair(QString(), v)});
    default:
        break;
    }
    return v;
}

QVariant representationToVariant(const QString &representation)
{
    bool ok;
    QVariant variant = variantFromString(representation, ok);

    // We have no floating-point properties, so this is most likely intended to be a string.
    if (static_cast<QMetaType::Type>(variant.userType()) == QMetaType::Float
            || static_cast<QMetaType::Type>(variant.userType()) == QMetaType::Double) {
        variant = variantFromString(QLatin1Char('"') + representation + QLatin1Char('"'), ok);
    }

    if (ok)
        return variant;

    // If it's not valid JavaScript, interpret the value as a string.
    return representation;
}

QVariant settingsValueToVariant(const QVariant &settingsValue)
{
    if (settingsValue.userType() == QMetaType::QVariantHash) {
        const QVariantHash h = settingsValue.toHash();
        if (h.size() == 1 && h.constBegin().key().isEmpty())
            return *h.constBegin();
    }
    return settingsValue;
}

} // namespace qbs
