#include "DelegateChooser.h"

#include "Logging.h"

// uses private API, which moved between versions
#include <QQmlEngine>
#include <QtGlobal>

QQmlComponent *
DelegateChoice::delegate() const
{
        return delegate_;
}

void
DelegateChoice::setDelegate(QQmlComponent *delegate)
{
        if (delegate != delegate_) {
                delegate_ = delegate;
                emit delegateChanged();
                emit changed();
        }
}

QVariant
DelegateChoice::roleValue() const
{
        return roleValue_;
}

void
DelegateChoice::setRoleValue(const QVariant &value)
{
        if (value != roleValue_) {
                roleValue_ = value;
                emit roleValueChanged();
                emit changed();
        }
}

QVariant
DelegateChooser::roleValue() const
{
        return roleValue_;
}

void
DelegateChooser::setRoleValue(const QVariant &value)
{
        if (value != roleValue_) {
                roleValue_ = value;
                recalcChild();
                emit roleValueChanged();
        }
}

QQmlListProperty<DelegateChoice>
DelegateChooser::choices()
{
        return QQmlListProperty<DelegateChoice>(this,
                                                this,
                                                &DelegateChooser::appendChoice,
                                                &DelegateChooser::choiceCount,
                                                &DelegateChooser::choice,
                                                &DelegateChooser::clearChoices);
}

void
DelegateChooser::appendChoice(QQmlListProperty<DelegateChoice> *p, DelegateChoice *c)
{
        DelegateChooser *dc = static_cast<DelegateChooser *>(p->object);
        dc->choices_.append(c);
}

int
DelegateChooser::choiceCount(QQmlListProperty<DelegateChoice> *p)
{
        return static_cast<DelegateChooser *>(p->object)->choices_.count();
}
DelegateChoice *
DelegateChooser::choice(QQmlListProperty<DelegateChoice> *p, int index)
{
        return static_cast<DelegateChooser *>(p->object)->choices_.at(index);
}
void
DelegateChooser::clearChoices(QQmlListProperty<DelegateChoice> *p)
{
        static_cast<DelegateChooser *>(p->object)->choices_.clear();
}

void
DelegateChooser::recalcChild()
{
        for (const auto choice : qAsConst(choices_)) {
                auto choiceValue = choice->roleValue();
                if (!roleValue_.isValid() || !choiceValue.isValid() || choiceValue == roleValue_) {
                        if (child_) {
                                child_->setParentItem(nullptr);
                                child_ = nullptr;
                        }

                        choice->delegate()->create(incubator, QQmlEngine::contextForObject(this));
                        return;
                }
        }
}

void
DelegateChooser::componentComplete()
{
        QQuickItem::componentComplete();
        recalcChild();
}

void
DelegateChooser::DelegateIncubator::statusChanged(QQmlIncubator::Status status)
{
        if (status == QQmlIncubator::Ready) {
                chooser.child_ = dynamic_cast<QQuickItem *>(object());
                if (chooser.child_ == nullptr) {
                        nhlog::ui()->error("Delegate has to be derived of Item!");
                        return;
                }

                chooser.child_->setParentItem(&chooser);
                connect(chooser.child_, &QQuickItem::heightChanged, &chooser, [this]() {
                        chooser.setHeight(chooser.child_->height());
                });
                chooser.setHeight(chooser.child_->height());
                QQmlEngine::setObjectOwnership(chooser.child_,
                                               QQmlEngine::ObjectOwnership::JavaScriptOwnership);
                emit chooser.childChanged();

        } else if (status == QQmlIncubator::Error) {
                for (const auto &e : errors())
                        nhlog::ui()->error("Error instantiating delegate: {}",
                                           e.toString().toStdString());
        }
}
