// Copyright (C) 2021 The Qt Company Ltd.
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GPL-3.0-only
#include <QtQml/QQmlEngine>
#include <QtQml/QQmlComponent>
#include <QtCore/QScopedPointer>
#include <QtQml/private/qqmlanybinding_p.h>
#include <QtQuickTestUtils/private/qmlutils_p.h>
#include "withbindable.h"

class tst_qqmlanybinding : public QQmlDataTest
{
    Q_OBJECT

public:
    tst_qqmlanybinding();

private slots:
    void basicActions_data();
    void basicActions();
    void unboundQQmlPropertyBindingDoesNotCrash();
};

tst_qqmlanybinding::tst_qqmlanybinding()
    : QQmlDataTest(QT_QMLTEST_DATADIR)
{
}

void tst_qqmlanybinding::basicActions_data()
{
    QTest::addColumn<QString>("fileName");
    QTest::addRow("old style") << QStringLiteral("oldstylebinding.qml");
    QTest::addRow("new style") << QStringLiteral("newstylebinding.qml");
}

static int getRefCount(const QQmlAnyBinding &binding)
{
    if (binding.isAbstractPropertyBinding()) {
        return binding.asAbstractBinding()->ref;
    } else {
        // this temporarily adds a refcount because we construc a new untypedpropertybinding
        // thus -1
        return QPropertyBindingPrivate::get(binding.asUntypedPropertyBinding())->refCount() - 1;
    }
}

void tst_qqmlanybinding::basicActions()
{
    QQmlEngine engine;
    QFETCH(QString, fileName);
    QQmlComponent comp(&engine, testFileUrl(fileName));
    QScopedPointer<QObject> root(comp.create());
    QVERIFY2(root, qPrintable(comp.errorString()));

    QQmlProperty prop(root.get(), "prop");
    QQmlProperty trigger(root.get(), "trigger");

    // sanity check
    QCOMPARE(prop.read().toInt(), 1);

    // We can take the binding from a property
    auto binding = QQmlAnyBinding::ofProperty(prop);
    if (fileName == u"oldstylebinding.qml") {
        // and it is a QQmlAbstractBinding,
        QVERIFY(binding.isAbstractPropertyBinding());
    } else {
        // and it is a new style binding,
        QVERIFY(binding.isUntypedPropertyBinding());
    }
    // which is not null.
    QVERIFY(binding);
    // Getting the binding did not remove it.
    trigger.write(42);
    QCOMPARE(prop.read().toInt(), 42);
    // remove does that,
    QQmlAnyBinding::removeBindingFrom(prop);
    QVERIFY(!QQmlAnyBinding::ofProperty(prop));
    // but does not change the value.
    QCOMPARE(prop.read().toInt(), 42);
    // As there is no binding anymore, there won't be any change if trigger changes.
    trigger.write(2);
    QCOMPARE(prop.read().toInt(), 42);
    // The binding we took is still valid (and we are currently the sole owner).
    QVERIFY(getRefCount(binding) == 1);
    // We can reinstall the binding
    binding.installOn(prop);
    // This changes the value to reflect that trigger has changed
    QCOMPARE(prop.read().toInt(), 2);
    // The binding behaves normally.
    trigger.write(3);
    QCOMPARE(prop.read().toInt(), 3);
    // "binding" still has a reference to the binding
    QVERIFY(getRefCount(binding) == 2);

    // aliases are resolved correctly
    QQmlProperty a2(root.get(), "a2");
    QCOMPARE(QQmlAnyBinding::ofProperty(a2), binding);
}

void tst_qqmlanybinding::unboundQQmlPropertyBindingDoesNotCrash()
{
    QQmlEngine engine;
    QQmlComponent comp(&engine, testFileUrl("unboundBinding.qml"));
    QScopedPointer<QObject> root(comp.create());
    QVERIFY2(root, qPrintable(comp.errorString()));

    QQmlProperty prop(root.get(), "prop");
    QQmlProperty trigger(root.get(), "trigger");

    // Store a reference to the binding of prop.
    auto binding = QQmlAnyBinding::ofProperty(prop);
    QVERIFY(binding.isUntypedPropertyBinding());
    QVERIFY(!binding.asUntypedPropertyBinding().isNull());

    // If we break the binding,
    prop.write(42);
    QCOMPARE(prop.read(), 42);
    {
        auto noBinding = QQmlAnyBinding::ofProperty(prop);
        QVERIFY(noBinding.asUntypedPropertyBinding().isNull());
    }
    // and trigger binding reevaluation
    trigger.write(1);
    // there is no crash.
    // When we reinstall the binding,
    binding.installOn(prop);
    // the value is correctly updated.
    QCOMPARE(prop.read(), 1);
}

QTEST_MAIN(tst_qqmlanybinding)

#include "tst_qqmlanybinding.moc"