// SPDX-License-Identifier: LGPL-2.1-or-later
//
// SPDX-FileCopyrightText: 2014 Sanjiban Bairagya <sanjiban22393@gmail.com>
//

#include "PlaybackFlyToItem.h"

#include "GeoDataCamera.h"
#include "GeoDataFlyTo.h"
#include "GeoDataLookAt.h"
#include "Quaternion.h"

#include <QTimer>

namespace Marble
{
PlaybackFlyToItem::PlaybackFlyToItem(const GeoDataFlyTo *flyTo)
    : m_flyTo(flyTo)
    , m_before(nullptr)
    , m_next(nullptr)
    , m_isPlaying(false)
    , m_isFirst(false)
{
    // do nothing
}

const GeoDataFlyTo *PlaybackFlyToItem::flyTo() const
{
    return m_flyTo;
}

double PlaybackFlyToItem::duration() const
{
    // We use duration 0 for first FlyTo for instantly flight to it.
    return m_isFirst ? 0 : m_flyTo->duration();
}

void PlaybackFlyToItem::play()
{
    if (m_isPlaying) {
        return;
    } else {
        m_isPlaying = true;
        if (!(m_start.isValid())) {
            m_start = QDateTime::currentDateTime();
            Q_ASSERT(m_start.isValid());
        } else {
            m_start = m_start.addMSecs(m_pause.msecsTo(QDateTime::currentDateTime()));
        }
        playNext();
    }
}

void PlaybackFlyToItem::playNext()
{
    if (!m_start.isValid()) {
        return;
    }
    double const progress = m_start.msecsTo(QDateTime::currentDateTime()) / 1000.0;
    Q_ASSERT(progress >= 0.0);
    double const t = progress / duration();
    if (t <= 1) {
        if (m_isPlaying) {
            center(t);
            Q_EMIT progressChanged(progress);
            QTimer::singleShot(5, this, SLOT(playNext()));
        }
    } else {
        center(1.0);
        Q_EMIT finished();
        stop();
    }
}

void PlaybackFlyToItem::pause()
{
    m_isPlaying = false;
    m_pause = QDateTime::currentDateTime();
}

void PlaybackFlyToItem::seek(double t)
{
    m_start = QDateTime::currentDateTime().addMSecs(-t * duration() * 1000);
    m_pause = QDateTime::currentDateTime();
    center(t);
}

void PlaybackFlyToItem::stop()
{
    m_isPlaying = false;
    m_start = QDateTime();
    m_pause = QDateTime();
}

void PlaybackFlyToItem::center(double t)
{
    Q_ASSERT(t >= 0.0 && t <= 1.0);
    Q_ASSERT(m_before);
    if (m_flyTo->flyToMode() == GeoDataFlyTo::Bounce || !m_before->m_before || !m_next) {
        GeoDataCoordinates const a = m_before->m_flyTo->view()->coordinates();
        GeoDataCoordinates const b = m_flyTo->view()->coordinates();
        Q_EMIT centerOn(a.interpolate(b, t));
    } else {
        Q_ASSERT(m_flyTo->flyToMode() == GeoDataFlyTo::Smooth);
        GeoDataCoordinates const a = m_before->m_before->m_flyTo->view()->coordinates();
        GeoDataCoordinates const b = m_before->m_flyTo->view()->coordinates();
        GeoDataCoordinates const c = m_flyTo->view()->coordinates();
        GeoDataCoordinates const d = m_next->m_flyTo->view()->coordinates();
        Q_EMIT centerOn(b.interpolate(a, c, d, t));
    }
}

void PlaybackFlyToItem::setBefore(PlaybackFlyToItem *before)
{
    m_before = before;
}

void PlaybackFlyToItem::setNext(PlaybackFlyToItem *next)
{
    m_next = next;
}

void PlaybackFlyToItem::setFirst(bool isFirst)
{
    m_isFirst = isFirst;
}

}

#include "moc_PlaybackFlyToItem.cpp"
