/******************************************************************************
 * konsolekalendarepoch.cpp                                                   *
 *                                                                            *
 * KonsoleKalendar is a command line interface to KDE calendars               *
 * SPDX-FileCopyrightText: 2002-2004 Tuukka Pasanen <illuusio@mailcity.com>   *
 * SPDX-FileCopyrightText: 2003-2005 Allen Winter <winter@kde.org>            *
 *                                                                            *
 * SPDX-License-Identifier: GPL-2.0-or-later WITH Qt-Commercial-exception-1.0 *
 *                                                                            *
 ******************************************************************************/
/**
 * @file konsolekalendarepoch.cpp
 * Provides the KonsoleKalendarEpoch class definition.
 * @author Tuukka Pasanen
 * @author Allen Winter
 */
#include "konsolekalendarepoch.h"

#include <cstdlib>
#include <iostream>

using namespace std;

KonsoleKalendarEpoch::KonsoleKalendarEpoch() = default;

KonsoleKalendarEpoch::~KonsoleKalendarEpoch() = default;

// By "epoch" we mean the number of seconds since 00:00:00 UTC on January 1 1970

// Function to convert an epoch value into a QDateTime
QDateTime KonsoleKalendarEpoch::epoch2QDateTime(uint epoch)
{
    QDateTime dt;
    dt.setSecsSinceEpoch(epoch);
    return dt;
}

// Function to convert a QDateTime value into an epoch
uint KonsoleKalendarEpoch::QDateTime2epoch(const QDateTime &dt)
{
    // THIS FUNCTION CAN BE OFF BY 1 HOUR DUE TO DAYLIGHT SAVINGS TIME.
    // SORRY QT DOESN'T HANDLE DAYLIGHT SAVINGS TIME.

    // Compute #seconds to subtract for local timezone difference from UTC.
    int offset = QDateTime::currentDateTimeUtc().toSecsSinceEpoch() - QDateTime::currentDateTime().toSecsSinceEpoch();
    return dt.toSecsSinceEpoch() - offset;
}

#if defined(TEST)
// Pass -DTEST to the compile command to create the test program, e.g:
// cc -DTEST -I/usr/local/KDE/include  konsolekalendarepoch.cpp
//           -L/usr/local/KDE/lib -lqt-mt -pthread
main()
{
    uint epoch;
    QDateTime dt;

    cout << endl;
    cout << "NOTE: Some tests may be off by 1 hour (3600 secs) "
         << "due to daylight savings time" << endl
         << endl;

    // Test1
    epoch = 0;
    dt = KonsoleKalendarEpoch::epoch2QDateTime(epoch);
    cout << "TEST 1:" << endl;
    cout << "epoch=" << epoch << " converts to " << dt.toString(Qt::TextDate) << endl;

    epoch = KonsoleKalendarEpoch::QDateTime2epoch(dt);
    cout << "date=" << dt.toString(Qt::TextDate) << " converts to "
         << "epoch=" << epoch << endl;

    // Test2
    epoch = 100000;
    dt = KonsoleKalendarEpoch::epoch2QDateTime(epoch);
    cout << "TEST 2:" << endl;
    cout << "epoch=" << epoch << " converts to " << dt.toString(Qt::TextDate) << endl;

    epoch = KonsoleKalendarEpoch::QDateTime2epoch(dt);
    cout << "date=" << dt.toString(Qt::TextDate) << " converts to "
         << "epoch=" << epoch << endl;

    // Test3
    epoch = 10000000;
    dt = KonsoleKalendarEpoch::epoch2QDateTime(epoch);
    cout << "TEST 3:" << endl;
    cout << "epoch=" << epoch << " converts to " << dt.toString(Qt::TextDate) << endl;

    epoch = KonsoleKalendarEpoch::QDateTime2epoch(dt);
    cout << "date=" << dt.toString(Qt::TextDate) << " converts to "
         << "epoch=" << epoch << endl;

    // Test4
    epoch = 1000000000;
    dt = KonsoleKalendarEpoch::epoch2QDateTime(epoch);
    cout << "TEST 4:" << endl;
    cout << "epoch=" << epoch << " converts to " << dt.toString(Qt::TextDate) << endl;

    epoch = KonsoleKalendarEpoch::QDateTime2epoch(dt);
    cout << "date=" << dt.toString(Qt::TextDate) << " converts to "
         << "epoch=" << epoch << endl;

    // Test5
    epoch = 10000000000;
    dt = KonsoleKalendarEpoch::epoch2QDateTime(epoch);
    cout << "TEST 5:" << endl;
    cout << "epoch=" << epoch << " converts to " << dt.toString(Qt::TextDate) << endl;

    epoch = KonsoleKalendarEpoch::QDateTime2epoch(dt);
    cout << "date=" << dt.toString(Qt::TextDate) << " converts to "
         << "epoch=" << epoch << endl;
}
#endif
