// Copyright (C) 2015 Jolla Ltd.
// Copyright (C) 2022 The Qt Company Ltd.
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only

#include "qdeclarativegeomapitemview_p.h"
#include "qdeclarativegeomap_p.h"
#include "qdeclarativegeomapitembase_p.h"

#include <QtCore/QAbstractItemModel>
#include <QtQml/QQmlContext>
#include <QtQuick/private/qquickanimation_p.h>
#include <QtQml/QQmlListProperty>

QT_BEGIN_NAMESPACE

/*!
    \qmltype MapItemView
    \nativetype QDeclarativeGeoMapItemView
    \inqmlmodule QtLocation
    \ingroup qml-QtLocation5-maps
    \since QtLocation 5.5
    \inherits QtObject

    \brief The MapItemView is used to populate Map from a model.

    The MapItemView is used to populate Map with MapItems from a model.
    The MapItemView type only makes sense when contained in a Map,
    meaning that it has no standalone presentation.

    \section2 Example Usage

    This example demonstrates how to use the MapViewItem object to display
    a \l{route}{route} on a \l{Map}{map}:

    \snippet declarative/maps.qml QtQuick import
    \snippet declarative/maps.qml QtLocation import
    \codeline
    \snippet declarative/maps.qml MapRoute
*/

/*!
    \qmlproperty Transition QtLocation::MapItemView::add

    This property holds the transition that is applied to the map items created by the view
    when they are instantiated and added to the map.

    \since QtLocation 5.12
*/

/*!
    \qmlproperty Transition QtLocation::MapItemView::remove

    This property holds the transition that is applied to the map items created by the view
    when they are removed.

    \since QtLocation 5.12
*/

QDeclarativeGeoMapItemView::QDeclarativeGeoMapItemView(QQuickItem *parent)
    : QDeclarativeGeoMapItemGroup(parent)
{
        m_exit = new QQuickTransition(this);
        QQmlListProperty<QQuickAbstractAnimation> anims = m_exit->animations();
        QQuickNumberAnimation *ani = new QQuickNumberAnimation(m_exit);
        ani->setProperty(QStringLiteral("opacity"));
        ani->setTo(0.0);
        ani->setDuration(300.0);
        anims.append(&anims, ani);
}

QDeclarativeGeoMapItemView::~QDeclarativeGeoMapItemView()
{
    // No need to remove instantiated items: if the MIV has instantiated items because it has been added
    // to a Map (or is child of a Map), the Map destructor takes care of removing it and the instantiated items.
}

/*!
    \internal
*/
void QDeclarativeGeoMapItemView::componentComplete()
{
    QDeclarativeGeoMapItemGroup::componentComplete();
    m_componentCompleted = true;
    if (!m_itemModel.isNull())
        m_delegateModel->setModel(m_itemModel);

    if (m_delegate)
        m_delegateModel->setDelegate(m_delegate);

    m_delegateModel->setDelegateModelAccess(m_delegateModelAccess);
    m_delegateModel->componentComplete();
}

void QDeclarativeGeoMapItemView::classBegin()
{
    QDeclarativeGeoMapItemGroup::classBegin();
    QQmlContext *ctx = qmlContext(this);
    m_delegateModel = new QQmlDelegateModel(ctx, this);
    m_delegateModel->classBegin();

    connect(m_delegateModel, &QQmlInstanceModel::modelUpdated, this, &QDeclarativeGeoMapItemView::modelUpdated);
    connect(m_delegateModel, &QQmlInstanceModel::createdItem, this, &QDeclarativeGeoMapItemView::createdItem);
//    connect(m_delegateModel, &QQmlInstanceModel::destroyingItem, this, &QDeclarativeGeoMapItemView::destroyingItem);
//    connect(m_delegateModel, &QQmlInstanceModel::initItem, this, &QDeclarativeGeoMapItemView::initItem);
}

void QDeclarativeGeoMapItemView::destroyingItem(QObject * /*object*/)
{

}

void QDeclarativeGeoMapItemView::initItem(int /*index*/, QObject * /*object*/)
{

}

void QDeclarativeGeoMapItemView::createdItem(int index, QObject * /*object*/)
{
    if (!m_map)
        return;
    // createdItem is emitted on asynchronous creation. In which case, object has to be invoked again.
    // See QQmlDelegateModel::object for further info.

    // DelegateModel apparently triggers this method in any case, that is:
    // 1. Synchronous incubation, delegate instantiated on the first object() call (during the object() call!)
    // 2. Async incubation, delegate not instantiated on the first object() call
    // 3. Async incubation, delegate present in the cache, and returned on the first object() call.
    //   createdItem also called during the object() call.
    if (m_creatingObject) {
        // Falling into case 1. or 3. Returning early to prevent double referencing the delegate instance.
        return;
    }

    QQuickItem *item = qobject_cast<QQuickItem *>(m_delegateModel->object(index, m_incubationMode));
    if (item)
        addDelegateToMap(item, index, true);
    else
        qWarning() << "QQmlDelegateModel:: object called in createdItem for " << index << " produced a null item";
}

void QDeclarativeGeoMapItemView::modelUpdated(const QQmlChangeSet &changeSet, bool reset)
{
    if (!m_map) // everything will be done in instantiateAllItems. Removal is done by declarativegeomap.
        return;

    // move changes are expressed as one remove + one insert, with the same moveId.
    // For simplicity, they will be treated as remove + insert.
    // Changes will be also ignored, as they represent only data changes, not layout changes
    if (reset) { // Assuming this means "remove everything already instantiated"
        removeInstantiatedItems();
    } else {
        // Remove items from the back to the front to retain the mapping to what is received from the changesets
        const QList<QQmlChangeSet::Change> &removes = changeSet.removes();
        std::map<int, int> mapRemoves;
        for (qsizetype i = 0; i < removes.size(); i++)
            mapRemoves.insert(std::pair<int, int>(removes.at(i).start(), i));

        for (auto rit = mapRemoves.rbegin(); rit != mapRemoves.rend(); ++rit) {
            const QQmlChangeSet::Change &c = removes.at(rit->second);
            for (auto idx = c.end() - 1; idx >= c.start(); --idx)
                removeDelegateFromMap(idx);
        }
    }

    QScopedValueRollback createBlocker(m_creatingObject, true);
    for (const QQmlChangeSet::Change &c: changeSet.inserts()) {
        for (auto idx = c.start(); idx < c.end(); idx++) {
            QObject *delegateInstance = m_delegateModel->object(idx, m_incubationMode);
            addDelegateToMap(qobject_cast<QQuickItem *>(delegateInstance), idx);
        }
    }

    fitViewport();
}

/*!
    \qmlproperty model QtLocation::MapItemView::model

    This property holds the model that provides data used for creating the map items defined by the
    delegate. Only QAbstractItemModel based models are supported.
*/
QVariant QDeclarativeGeoMapItemView::model() const
{
    return m_itemModel;
}

void QDeclarativeGeoMapItemView::setModel(const QVariant &model)
{
    if (model == m_itemModel)
        return;

    m_itemModel = model;
    if (m_componentCompleted) {

        // Make sure to clear all stale items from the map and the model
        m_delegateModel->drainReusableItemsPool(0);
        removeInstantiatedItems(false);

        m_delegateModel->setModel(m_itemModel);
    }

    emit modelChanged();
}

/*!
    \qmlproperty Component QtLocation::MapItemView::delegate

    This property holds the delegate which defines how each item in the
    model should be displayed. The Component must contain exactly one
    MapItem -derived object as the root object.
*/
QQmlComponent *QDeclarativeGeoMapItemView::delegate() const
{
    return m_delegate;
}

void QDeclarativeGeoMapItemView::setDelegate(QQmlComponent *delegate)
{
    if (m_delegate == delegate)
        return;

    m_delegate = delegate;
    if (m_componentCompleted)
        m_delegateModel->setDelegate(m_delegate);

    emit delegateChanged();
}

/*!
    \qmlproperty bool QtLocation::MapItemView::autoFitViewport

    This property controls whether to automatically pan and zoom the viewport
    to display all map items when items are added or removed.

    Defaults to false.
*/
bool QDeclarativeGeoMapItemView::autoFitViewport() const
{
    return m_fitViewport;
}

void QDeclarativeGeoMapItemView::setAutoFitViewport(const bool &fit)
{
    if (fit == m_fitViewport)
        return;
    m_fitViewport = fit;
    fitViewport();
    emit autoFitViewportChanged();
}

/*!
    \internal
*/
void QDeclarativeGeoMapItemView::fitViewport()
{

    if (!m_map || !m_map->mapReady() || !m_fitViewport)
        return;

    if (m_map->mapItems().size() > 0)
        m_map->fitViewportToMapItems();
}

/*!
    \internal
*/
void QDeclarativeGeoMapItemView::setMap(QDeclarativeGeoMap *map)
{
    if (!map || m_map) // changing map on the fly not supported
        return;
    m_map = map;
    instantiateAllItems();
}

/*!
    \internal
*/
void QDeclarativeGeoMapItemView::removeInstantiatedItems(bool transition)
{
    if (!m_map)
        return;

    // with transition = false removeInstantiatedItems aborts ongoing exit transitions //QTBUG-69195
    // Backward as removeItemFromMap modifies m_instantiatedItems
    for (qsizetype i = m_instantiatedItems.size() -1; i >= 0 ; i--)
        removeDelegateFromMap(i, transition);
}

/*!
    \internal

    Instantiates all items.
*/
void QDeclarativeGeoMapItemView::instantiateAllItems()
{
    // The assumption is that if m_instantiatedItems isn't empty, instantiated items have been already added
    if (!m_componentCompleted || !m_map || !m_delegate || m_itemModel.isNull() || !m_instantiatedItems.isEmpty())
        return;

    // If here, m_delegateModel may contain data, but QQmlInstanceModel::object for each row hasn't been called yet.
    QScopedValueRollback createBlocker(m_creatingObject, true);
    for (qsizetype i = 0; i < m_delegateModel->count(); i++) {
        QObject *delegateInstance = m_delegateModel->object(i, m_incubationMode);
        addDelegateToMap(qobject_cast<QQuickItem *>(delegateInstance), i);
    }

    fitViewport();
}

void QDeclarativeGeoMapItemView::setIncubateDelegates(bool useIncubators)
{
    const QQmlIncubator::IncubationMode incubationMode =
            (useIncubators) ? QQmlIncubator::Asynchronous : QQmlIncubator::Synchronous;
    if (m_incubationMode == incubationMode)
        return;
    m_incubationMode = incubationMode;
    emit incubateDelegatesChanged();
}

bool QDeclarativeGeoMapItemView::incubateDelegates() const
{
    return m_incubationMode == QQmlIncubator::Asynchronous;
}

/*!
    \qmlproperty enumeration QtLocation::MapItemView::delegateModelAccess
    \since 6.10

    This property determines how delegates can access the model.

    \value DelegateModel.ReadOnly
        Prohibit delegates from writing the model via either context properties,
        the \c model object, or required properties.

    \value DelegateModel.ReadWrite
        Allow delegates to write the model via either context properties,
        the \c model object, or required properties.

    \value DelegateModel.Qt5ReadWrite
        Allow delegates to write the model via the \c model object and context
        properties but \e not via required properties.

    The default is \c DelegateModel.Qt5ReadWrite.

    \sa {Models and Views in Qt Quick#Changing Model Data}
*/
QQmlDelegateModel::DelegateModelAccess QDeclarativeGeoMapItemView::delegateModelAccess() const
{
    return m_delegateModelAccess;
}

void QDeclarativeGeoMapItemView::setDelegateModelAccess(
        QQmlDelegateModel::DelegateModelAccess delegateModelAccess)
{
    if (m_delegateModelAccess == delegateModelAccess)
        return;

    m_delegateModelAccess = delegateModelAccess;
    if (m_componentCompleted)
        m_delegateModel->setDelegateModelAccess(m_delegateModelAccess);

    emit delegateModelAccessChanged();
}

QList<QQuickItem *> QDeclarativeGeoMapItemView::mapItems()
{
    return m_instantiatedItems;
}

QQmlInstanceModel::ReleaseFlags QDeclarativeGeoMapItemView::disposeDelegate(QQuickItem *item)
{
    disconnect(item, 0, this, 0);
    removeDelegateFromMap(item);
    item->setParentItem(nullptr);   // Needed because
    item->setParent(nullptr);       // m_delegateModel->release(item) does not destroy the item most of the times!!
    QQmlInstanceModel::ReleaseFlags releaseStatus = m_delegateModel->release(item);
    return releaseStatus;
}

void QDeclarativeGeoMapItemView::removeDelegateFromMap(int index, bool transition)
{
    if (index >= 0 && index < m_instantiatedItems.size()) {
        QQuickItem *item = m_instantiatedItems.takeAt(index);
        if (!item) { // not yet incubated
            // Don't cancel incubation explicitly when model rows are removed, as DelegateModel
            // apparently takes care of incubating elements when the model remove those indices.
            // Cancel them explicitly only when a MIV is removed from a map.
            if (!transition)
                m_delegateModel->cancel(index);
            return;
        }
        // item can be either a QDeclarativeGeoMapItemBase or a QDeclarativeGeoMapItemGroup (subclass)
        if (m_exit && m_map && transition) {
            transitionItemOut(item);
        } else {
            if (m_exit && m_map && !transition) {
                // check if the exit transition is still running, if so stop it.
                // This can happen when explicitly calling Map.removeMapItemView, soon after adding it.
                terminateExitTransition(item);
            }
            QQmlInstanceModel::ReleaseFlags releaseStatus = disposeDelegate(item);
#ifdef QT_DEBUG
            if (releaseStatus == QQmlInstanceModel::Referenced)
                qWarning() << "item "<< index << "(" << item << ") still referenced";
#else
            Q_UNUSED(releaseStatus);
#endif
        }
    }
}

void QDeclarativeGeoMapItemView::removeDelegateFromMap(QQuickItem *o)
{
    if (!m_map)
        return;

    QDeclarativeGeoMapItemBase *item = qobject_cast<QDeclarativeGeoMapItemBase *>(o);
    if (item) {
        m_map->removeMapItem(item);
        return;
    }
    QDeclarativeGeoMapItemView *view = qobject_cast<QDeclarativeGeoMapItemView *>(o);
    if (view) {
        m_map->removeMapItemView(view);
        return;
    }
    QDeclarativeGeoMapItemGroup *group = qobject_cast<QDeclarativeGeoMapItemGroup *>(o);
    if (group) {
        m_map->removeMapItemGroup(group);
        return;
    }
}

void QDeclarativeGeoMapItemView::transitionItemOut(QQuickItem *o)
{
    QDeclarativeGeoMapItemGroup *group = qobject_cast<QDeclarativeGeoMapItemGroup *>(o);
    if (group) {
        if (!group->m_transitionManager) {
            std::unique_ptr<QDeclarativeGeoMapItemTransitionManager>manager(new QDeclarativeGeoMapItemTransitionManager(group));
            group->m_transitionManager.swap(manager);
            group->m_transitionManager->m_view = this;
        }
        connect(group, &QDeclarativeGeoMapItemGroup::removeTransitionFinished,
                this, &QDeclarativeGeoMapItemView::exitTransitionFinished);

        group->m_transitionManager->transitionExit();
        return;
    }
    QDeclarativeGeoMapItemBase *item = qobject_cast<QDeclarativeGeoMapItemBase *>(o);
    if (item) {
        if (!item->m_transitionManager) {
            std::unique_ptr<QDeclarativeGeoMapItemTransitionManager> manager(new QDeclarativeGeoMapItemTransitionManager(item));
            item->m_transitionManager.swap(manager);
            item->m_transitionManager->m_view = this;
        }
        connect(item, &QDeclarativeGeoMapItemBase::removeTransitionFinished,
                this, &QDeclarativeGeoMapItemView::exitTransitionFinished);

        item->m_transitionManager->transitionExit();
        return;
    }
}

void QDeclarativeGeoMapItemView::terminateExitTransition(QQuickItem *o)
{
    QDeclarativeGeoMapItemGroup *group = qobject_cast<QDeclarativeGeoMapItemGroup *>(o);
    if (group && group->m_transitionManager) {
        group->m_transitionManager->cancel();
        return;
    }
    QDeclarativeGeoMapItemBase *item = qobject_cast<QDeclarativeGeoMapItemBase *>(o);
    if (item && item->m_transitionManager) {
        item->m_transitionManager->cancel();
        return;
    }
}

void QDeclarativeGeoMapItemView::exitTransitionFinished()
{
    QQuickItem *item = qobject_cast<QQuickItem *>(sender());
    if (!item)
        return;
    QQmlInstanceModel::ReleaseFlags releaseStatus = disposeDelegate(item);
#ifdef QT_DEBUG
    if (releaseStatus == QQmlInstanceModel::Referenced)
        qWarning() << "item "<<item<<" still referenced";
#else
    Q_UNUSED(releaseStatus);
#endif
}

void QDeclarativeGeoMapItemView::addItemToMap(QDeclarativeGeoMapItemBase *item, int index, bool createdItem)
{

    if (m_map && item->quickMap() == m_map) // test for *item done in the caller
        return;

    if (m_map) {
        insertInstantiatedItem(index, item, createdItem);
        item->setParentItem(this);
        m_map->addMapItem(item);
        if (m_enter) {
            if (!item->m_transitionManager) {
                std::unique_ptr<QDeclarativeGeoMapItemTransitionManager>manager(new QDeclarativeGeoMapItemTransitionManager(item));
                item->m_transitionManager.swap(manager);
            }
            item->m_transitionManager->m_view = this;
            item->m_transitionManager->transitionEnter();
        }
    }
}

void QDeclarativeGeoMapItemView::insertInstantiatedItem(int index, QQuickItem *o, bool createdItem)
{
    if (createdItem)
        m_instantiatedItems.replace(index, o);
    else
        m_instantiatedItems.insert(index, o);
}

void QDeclarativeGeoMapItemView::addItemViewToMap(QDeclarativeGeoMapItemView *item, int index, bool createdItem)
{
    if (m_map && item->quickMap() == m_map)  // test for *item done in the caller
        return;

    if (m_map) {
        insertInstantiatedItem(index, item, createdItem);
        item->setParentItem(this);
        m_map->addMapItemView(item);
        if (m_enter) {
            if (!item->m_transitionManager) {
                std::unique_ptr<QDeclarativeGeoMapItemTransitionManager> manager(new QDeclarativeGeoMapItemTransitionManager(item));
                item->m_transitionManager.swap(manager);
            }
            item->m_transitionManager->m_view = this;
            item->m_transitionManager->transitionEnter();
        }
    }
}

void QDeclarativeGeoMapItemView::addItemGroupToMap(QDeclarativeGeoMapItemGroup *item, int index, bool createdItem)
{
    if (m_map && item->quickMap() == m_map) // test for *item done in the caller
        return;

    if (m_map) {
        insertInstantiatedItem(index, item, createdItem);
        item->setParentItem(this);
        m_map->addMapItemGroup(item);
        if (m_enter) {
            if (!item->m_transitionManager) {
                std::unique_ptr<QDeclarativeGeoMapItemTransitionManager>manager(new QDeclarativeGeoMapItemTransitionManager(item));
                item->m_transitionManager.swap(manager);
            }
            item->m_transitionManager->m_view = this;
            item->m_transitionManager->transitionEnter();
        }
    }
}

void QDeclarativeGeoMapItemView::addDelegateToMap(QQuickItem *object, int index, bool createdItem)
{
    if (!object) {
        if (!createdItem)
            m_instantiatedItems.insert(index, nullptr); // insert placeholder
        return;
    }
    QDeclarativeGeoMapItemBase *item = qobject_cast<QDeclarativeGeoMapItemBase *>(object);
    if (item) { // else createdItem will be emitted.
        addItemToMap(item, index, createdItem);
        return;
    }
    QDeclarativeGeoMapItemView *view = qobject_cast<QDeclarativeGeoMapItemView *>(object);
    if (view) {
        addItemViewToMap(view, index, createdItem);
        return;
    }
    QDeclarativeGeoMapItemGroup *group = qobject_cast<QDeclarativeGeoMapItemGroup *>(object);
    if (group) {
        addItemGroupToMap(group, index, createdItem);
        return;
    }
    qWarning() << "addDelegateToMap called with a "<< object->metaObject()->className();
}

QT_END_NAMESPACE