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

#pragma once

#include <QComboBox>
#include <QColor>
#include <QVector>

#include <optional>

// A combo box whose items are refreshed by live updates. SetItems() leaves the items alone when
// they are unchanged, and while the popup is open it holds the change back until the popup has
// closed, so a live update never closes the dropdown or moves the selection under the user.
// Replacing the items keeps the selection by item data (the first item when it is gone) and emits
// no currentIndexChanged; a replacement held back over an open popup emits itemsReplaced() instead.
class LiveComboBox : public QComboBox {
    Q_OBJECT
public:
    struct Item {
        QString text;
        QVariant data;
        QString tooltip;
        QColor swatch;           // shown as a small square icon when valid
        bool separator = false;
        bool operator==(const Item &other) const = default;
    };

    explicit LiveComboBox(QWidget *parent = nullptr);
    // True if the items were replaced now; false if unchanged or held back for an open popup.
    bool SetItems(const QVector<Item> &items);

signals:
    void itemsReplaced();

private:
    QVector<Item> items_;
    std::optional<QVector<Item>> pending_;

    void Replace(const QVector<Item> &items);
    void ApplyPending();
    bool eventFilter(QObject *watched, QEvent *event) override;
};