#include <QComboBox>
#include <QSortFilterProxyModel>
#include <QStandardItemModel>
#include <QTest>

class TestComboWithLargeModel : public QObject
{
    Q_OBJECT

private Q_SLOTS:
    void create();
};

enum { ExpiredRole = Qt::UserRole + 1, TrainingRole };

class FilterProxy : public QSortFilterProxyModel
{
public:
    void setIncludeExpired(bool b)
    {
        m_includeExpired = b;
        invalidateRowsFilter();
    }

    void setIncludeTrainings(bool b)
    {
        m_includeTrainings = b;
        invalidateRowsFilter();
    }

    int persistentIndexes() const { return persistentIndexList().count(); }

protected:
    bool filterAcceptsRow(int source_row, const QModelIndex &source_parent) const override {
        const auto sourceIndex = sourceModel()->index(source_row, 0, source_parent);
        return (m_includeExpired || !sourceIndex.data(ExpiredRole).toBool())
            && (m_includeTrainings || !sourceIndex.data(TrainingRole).toBool());
    }

private:
    bool m_includeExpired = false;
    bool m_includeTrainings = false;
};

void TestComboWithLargeModel::create()
{
    // Show a window, just so that QWindowsUiaAccessibility::handleWmGetObject is called
    QWidget w;
    w.show();
    qApp->processEvents();
    w.hide();

    // Base model
    const int rows = 1000;
    int nonTrainings = 0;
    QStandardItemModel largeModel(rows, 1);
    for (int row = 0; row < rows; ++row) {
        const auto index = largeModel.index(row, 0);
        largeModel.setData(index, QStringLiteral("Project %1").arg(row));
        largeModel.setData(index, row < rows-40, ExpiredRole); // the last 40 are active (non-expired)
        const bool isTraining = (row % 10) == 0 && row < rows - 40;
        largeModel.setData(index, isTraining, TrainingRole);
        if (!isTraining)
            ++nonTrainings;
    }
    // Proxy
    FilterProxy proxy;
    proxy.setSourceModel(&largeModel);

    QBENCHMARK {
        QElapsedTimer dt;
        dt.start();
        qDebug() << "Creating combo";
        QComboBox combo;
        combo.setEditable(true);
        combo.setModel(&proxy);
        combo.setCurrentText(""); // QWindowsUiaMainProvider::notifyValueChange iterates over all cells trying to find that value, creating a persistent index for each
        qDebug() << "initial count" << combo.count() << "active (non-expired) projects, with" << proxy.persistentIndexes() << "persistent indexes";
        QCOMPARE(combo.count(), 40);

        qDebug() << "Calling setIncludeExpired";
        proxy.setIncludeExpired(true); // this pushes the current index down for each rowInserted call, calling QWindowsUiaMainProvider::notifyValueChange every time
        qDebug() << "after setIncludeExpired:" << combo.count() << "rows," << proxy.persistentIndexes() << "persistent indexes";
        
        qDebug() << "Calling setIncludeTrainings";
        QCOMPARE(combo.count(), nonTrainings);
        proxy.setIncludeTrainings(true);
        qDebug() << "after setIncludeTrainings:" << combo.count() << "rows," << proxy.persistentIndexes() << "persistent indexes";
        
        QCOMPARE(combo.count(), rows);        
        qDebug() << dt.elapsed() << "ms";
    }
}

QTEST_MAIN(TestComboWithLargeModel)

#include "tst_comboWithLargeModel.moc"