// SPDX-FileCopyrightText: 2026 Filip Leonarski, Paul Scherrer Institute <filip.leonarski@psi.ch>
// SPDX-License-Identifier: GPL-3.0-only

#include "LiveComboBox.h"

#include <QAbstractItemView>
#include <QEvent>
#include <QIcon>
#include <QPixmap>
#include <QSignalBlocker>
#include <QTimer>

LiveComboBox::LiveComboBox(QWidget *parent) : QComboBox(parent) {
    // The popup is a separate window holding the view. Not every way of closing it goes through
    // hidePopup() (a click outside just hides the window), so watch the window itself.
    view()->window()->installEventFilter(this);
}

bool LiveComboBox::SetItems(const QVector<Item> &items) {
    if (view()->isVisible()) {
        pending_ = items;
        return false;
    }
    pending_.reset();
    if (items == items_)
        return false;
    Replace(items);
    return true;
}

void LiveComboBox::Replace(const QVector<Item> &items) {
    QSignalBlocker blocker(this);
    const QVariant selected = currentData();
    clear();
    for (const auto &item : items) {
        if (item.separator) {
            insertSeparator(count());
            continue;
        }
        if (item.swatch.isValid()) {
            QPixmap pixmap(14, 14);
            pixmap.fill(item.swatch);
            addItem(QIcon(pixmap), item.text, item.data);
        } else
            addItem(item.text, item.data);
        if (!item.tooltip.isEmpty())
            setItemData(count() - 1, item.tooltip, Qt::ToolTipRole);
    }
    items_ = items;
    const int index = selected.isValid() ? findData(selected) : -1;
    setCurrentIndex(index >= 0 ? index : (count() > 0 ? 0 : -1));
}

void LiveComboBox::ApplyPending() {
    if (!pending_ || view()->isVisible())
        return;
    const QVector<Item> items = std::move(*pending_);
    pending_.reset();
    if (items == items_)
        return;
    Replace(items);
    emit itemsReplaced();
}

bool LiveComboBox::eventFilter(QObject *watched, QEvent *event) {
    // Queued: a click on an item hides the popup first and selects the item afterwards, so the
    // held-back items go in once the pick has landed, and keep it.
    if (event->type() == QEvent::Hide && pending_)
        QTimer::singleShot(0, this, &LiveComboBox::ApplyPending);
    return QComboBox::eventFilter(watched, event);
}