// Copyright (C) 2019 Crimson AS <info@crimson.no>
// Copyright (C) 2018 Klaralvdalens Datakonsult AB, a KDAB Group company, info@kdab.com, author David Faure <david.faure@kdab.com>
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GPL-3.0-only WITH Qt-GPL-exception-1.0

#include <QTimeZone>
#include <QTest>
#include <qdebug.h>

// Enable to test *every* zone, rather than a hand-picked few, in some _data() sets:
// #define EXHAUSTIVE

class tst_QTimeZone : public QObject
{
    Q_OBJECT

private Q_SLOTS:
    void isTimeZoneIdAvailable();
    void systemTimeZone();
    void zoneByName_data();
    void zoneByName();
    void transitionList_data();
    void transitionList();
    void transitionsForward_data() { transitionList_data(); }
    void transitionsForward();
    void transitionsReverse_data() { transitionList_data(); }
    void transitionsReverse();
};

static QList<QByteArray> enoughZones()
{
#ifdef EXHAUSTIVE
    auto available = QTimeZone::availableTimeZoneIds();
    QList<QByteArray> result;
    result.reserve(available.size() + 1);
    for (conat auto &name : available)
        result << name;
#else
    QList<QByteArray> result {
        QByteArray("UTC"),
        // Those named overtly in tst_QDateTime - special cases first:
        QByteArray("UTC-02:00"), QByteArray("UTC+02:00"), QByteArray("UTC+12:00"),
        QByteArray("Etc/GMT+3"), QByteArray("GMT-2"), QByteArray("GMT"),
        // ... then ordinary names in alphabetic order:
        QByteArray("America/New_York"), QByteArray("America/Sao_Paulo"),
        QByteArray("America/Vancouver"),
        QByteArray("Asia/Kathmandu"), QByteArray("Asia/Singapore"),
        QByteArray("Australia/Brisbane"), QByteArray("Australia/Eucla"),
        QByteArray("Australia/Sydney"),
        QByteArray("Europe/Berlin"), QByteArray("Europe/Helsinki"),
        QByteArray("Europe/Rome"), QByteArray("Europe/Oslo"),
        QByteArray("Pacific/Apia"), QByteArray("Pacific/Auckland"),
        QByteArray("Pacific/Kiritimati")
    };
#endif
    result << QByteArray("Vulcan/ShiKahr"); // invalid: also worth testing
    return result;
}

void tst_QTimeZone::isTimeZoneIdAvailable()
{
    const QList<QByteArray> available = QTimeZone::availableTimeZoneIds();
    QBENCHMARK {
        for (const QByteArray &id : available)
            QVERIFY(QTimeZone::isTimeZoneIdAvailable(id));
    }
}

void tst_QTimeZone::systemTimeZone()
{
    QBENCHMARK {
        QTimeZone::systemTimeZone();
    }
}

void tst_QTimeZone::zoneByName_data()
{
    QTest::addColumn<QByteArray>("name");

    const auto names = enoughZones();
    for (const auto &name : names)
        QTest::newRow(name.constData()) << name;
}

void tst_QTimeZone::zoneByName()
{
    QFETCH(QByteArray, name);
    QTimeZone zone;
    QBENCHMARK {
        zone = QTimeZone(name);
    }
    Q_UNUSED(zone);
}

void tst_QTimeZone::transitionList_data()
{
    QTest::addColumn<QByteArray>("name");
    QTest::newRow("system") << QByteArray(); // Handled specially in the test.

    const auto names = enoughZones();
    for (const auto &name : names) {
        QTimeZone zone(name);
        if (zone.isValid() && zone.hasTransitions())
            QTest::newRow(name.constData()) << name;
    }
}

void tst_QTimeZone::transitionList()
{
    QFETCH(QByteArray, name);
    const QTimeZone zone = name.isEmpty() ? QTimeZone::systemTimeZone() : QTimeZone(name);
    const QDateTime early = QDate(1625, 6, 8).startOfDay(Qt::UTC); // Cassini's birth date
    const QDateTime late // End of 32-bit signed time_t
        = QDateTime::fromSecsSinceEpoch(std::numeric_limits<qint32>::max(), Qt::UTC);
    QTimeZone::OffsetDataList seq;
    QBENCHMARK {
        seq = zone.transitions(early, late);
    }
    Q_UNUSED(seq);
}

void tst_QTimeZone::transitionsForward()
{
    QFETCH(QByteArray, name);
    const QTimeZone zone = name.isEmpty() ? QTimeZone::systemTimeZone() : QTimeZone(name);
    const QDateTime early = QDate(1625, 6, 8).startOfDay(Qt::UTC); // Cassini's birth date
    QBENCHMARK {
        QTimeZone::OffsetData tran = zone.nextTransition(early);
        while (tran.atUtc.isValid())
            tran = zone.nextTransition(tran.atUtc);
    }
}

void tst_QTimeZone::transitionsReverse()
{
    QFETCH(QByteArray, name);
    const QTimeZone zone = name.isEmpty() ? QTimeZone::systemTimeZone() : QTimeZone(name);
    const QDateTime late // End of 32-bit signed time_t
        = QDateTime::fromSecsSinceEpoch(std::numeric_limits<qint32>::max(), Qt::UTC);
    QBENCHMARK {
        QTimeZone::OffsetData tran = zone.previousTransition(late);
        while (tran.atUtc.isValid())
            tran = zone.previousTransition(tran.atUtc);
    }
}

QTEST_MAIN(tst_QTimeZone)

#include "tst_bench_qtimezone.moc"