// Copyright (C) 2016 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 "qtbuttonpropertybrowser_p.h"

#include <QtWidgets/qgridlayout.h>
#include <QtWidgets/qlabel.h>
#include <QtWidgets/qtoolbutton.h>

#include <QtCore/qhash.h>

QT_BEGIN_NAMESPACE

class QtButtonPropertyBrowserPrivate
{
    QtButtonPropertyBrowser *q_ptr = nullptr;
    Q_DECLARE_PUBLIC(QtButtonPropertyBrowser)
public:

    void init(QWidget *parent);

    void propertyInserted(QtBrowserItem *index, QtBrowserItem *afterIndex);
    void propertyRemoved(QtBrowserItem *index);
    void propertyChanged(QtBrowserItem *index);
    QWidget *createEditor(QtProperty *property, QWidget *parent) const
        { return q_ptr->createEditor(property, parent); }

    void slotEditorDestroyed();
    void slotUpdate();
    void slotToggled(bool checked);

    struct WidgetItem
    {
        QWidget *widget{nullptr}; // can be null
        QLabel *label{nullptr}; // main label with property name
        QLabel *widgetLabel{nullptr}; // label substitute showing the current value if there is no widget
        QToolButton *button{nullptr}; // expandable button for items with children
        QWidget *container{nullptr}; // container which is expanded when the button is clicked
        QGridLayout *layout{nullptr}; // layout in container
        WidgetItem *parent{nullptr};
        QList<WidgetItem *> children;
        bool expanded{false};
    };
private:
    void updateLater();
    void updateItem(WidgetItem *item);
    static void insertRow(QGridLayout *layout, int row);
    static void removeRow(QGridLayout *layout, int row);
    int gridRow(WidgetItem *item) const;
    static int gridSpan(WidgetItem *item);
    void setExpanded(WidgetItem *item, bool expanded);
    static QToolButton *createButton(QWidget *parent = nullptr);

    QHash<QtBrowserItem *, WidgetItem *> m_indexToItem;
    QHash<WidgetItem *, QtBrowserItem *> m_itemToIndex;
    QHash<QWidget *, WidgetItem *> m_widgetToItem;
    QHash<QObject *, WidgetItem *> m_buttonToItem;
    QGridLayout *m_mainLayout = nullptr;
    QList<WidgetItem *> m_children;
    QList<WidgetItem *> m_recreateQueue;
};

QToolButton *QtButtonPropertyBrowserPrivate::createButton(QWidget *parent)
{
    auto *button = new QToolButton(parent);
    button->setCheckable(true);
    button->setSizePolicy(QSizePolicy(QSizePolicy::Preferred, QSizePolicy::Fixed));
    button->setToolButtonStyle(Qt::ToolButtonTextBesideIcon);
    button->setArrowType(Qt::DownArrow);
    button->setIconSize(QSize(3, 16));
    /*
    QIcon icon;
    icon.addPixmap(q_ptr->style()->standardPixmap(QStyle::SP_ArrowDown), QIcon::Normal, QIcon::Off);
    icon.addPixmap(q_ptr->style()->standardPixmap(QStyle::SP_ArrowUp), QIcon::Normal, QIcon::On);
    button->setIcon(icon);
    */
    return button;
}

int QtButtonPropertyBrowserPrivate::gridRow(WidgetItem *item) const
{
    QList<WidgetItem *> siblings;
    if (item->parent)
        siblings = item->parent->children;
    else
        siblings = m_children;

    int row = 0;
    for (WidgetItem *sibling : std::as_const(siblings)) {
        if (sibling == item)
            return row;
        row += gridSpan(sibling);
    }
    return -1;
}

int QtButtonPropertyBrowserPrivate::gridSpan(WidgetItem *item)
{
    if (item->container && item->expanded)
        return 2;
    return 1;
}

void QtButtonPropertyBrowserPrivate::init(QWidget *parent)
{
    m_mainLayout = new QGridLayout();
    parent->setLayout(m_mainLayout);
    auto *item = new QSpacerItem(0, 0, QSizePolicy::Fixed, QSizePolicy::Expanding);
    m_mainLayout->addItem(item, 0, 0);
}

void QtButtonPropertyBrowserPrivate::slotEditorDestroyed()
{
    auto *editor = qobject_cast<QWidget *>(q_ptr->sender());
    if (!editor)
        return;
    const auto it = m_widgetToItem.find(editor);
    if (it != m_widgetToItem.end()) {
        it.value()->widget = nullptr;
        m_widgetToItem.erase(it);
    }
}

void QtButtonPropertyBrowserPrivate::slotUpdate()
{
    for (WidgetItem *item : std::as_const(m_recreateQueue)) {
        WidgetItem *parent = item->parent;
        QWidget *w = nullptr;
        QGridLayout *l = nullptr;
        const int oldRow = gridRow(item);
        if (parent) {
            w = parent->container;
            l = parent->layout;
        } else {
            w = q_ptr;
            l = m_mainLayout;
        }

        int span = 1;
        if (!item->widget && !item->widgetLabel)
            span = 2;
        item->label = new QLabel(w);
        item->label->setSizePolicy(QSizePolicy(QSizePolicy::Fixed, QSizePolicy::Fixed));
        l->addWidget(item->label, oldRow, 0, 1, span);

        updateItem(item);
    }
    m_recreateQueue.clear();
}

void QtButtonPropertyBrowserPrivate::setExpanded(WidgetItem *item, bool expanded)
{
    if (item->expanded == expanded)
        return;

    if (!item->container)
        return;

    item->expanded = expanded;
    const int row = gridRow(item);
    WidgetItem *parent = item->parent;
    QGridLayout *l = nullptr;
    if (parent)
        l = parent->layout;
    else
        l = m_mainLayout;

    if (expanded) {
        insertRow(l, row + 1);
        l->addWidget(item->container, row + 1, 0, 1, 2);
        item->container->show();
    } else {
        l->removeWidget(item->container);
        item->container->hide();
        removeRow(l, row + 1);
    }

    item->button->setChecked(expanded);
    item->button->setArrowType(expanded ? Qt::UpArrow : Qt::DownArrow);
}

void QtButtonPropertyBrowserPrivate::slotToggled(bool checked)
{
    WidgetItem *item = m_buttonToItem.value(q_ptr->sender());
    if (!item)
        return;

    setExpanded(item, checked);

    if (checked)
        emit q_ptr->expanded(m_itemToIndex.value(item));
    else
        emit q_ptr->collapsed(m_itemToIndex.value(item));
}

void QtButtonPropertyBrowserPrivate::updateLater()
{
    QMetaObject::invokeMethod(q_ptr, [this] { slotUpdate(); }, Qt::QueuedConnection);
}

void QtButtonPropertyBrowserPrivate::propertyInserted(QtBrowserItem *index, QtBrowserItem *afterIndex)
{
    WidgetItem *afterItem = m_indexToItem.value(afterIndex);
    WidgetItem *parentItem = m_indexToItem.value(index->parent());

    auto *newItem = new WidgetItem();
    newItem->parent = parentItem;

    QGridLayout *layout = nullptr;
    QWidget *parentWidget = nullptr;
    int row = -1;
    if (!afterItem) {
        row = 0;
        if (parentItem)
            parentItem->children.insert(0, newItem);
        else
            m_children.insert(0, newItem);
    } else {
        row = gridRow(afterItem) + gridSpan(afterItem);
        if (parentItem)
            parentItem->children.insert(parentItem->children.indexOf(afterItem) + 1, newItem);
        else
            m_children.insert(m_children.indexOf(afterItem) + 1, newItem);
    }

    if (!parentItem) {
        layout = m_mainLayout;
        parentWidget = q_ptr;
    } else {
        if (!parentItem->container) {
            m_recreateQueue.removeAll(parentItem);
            WidgetItem *grandParent = parentItem->parent;
            QGridLayout *l = nullptr;
            const int oldRow = gridRow(parentItem);
            if (grandParent) {
                l = grandParent->layout;
            } else {
                l = m_mainLayout;
            }
            auto *container = new QFrame();
            container->setFrameShape(QFrame::Panel);
            container->setFrameShadow(QFrame::Raised);
            parentItem->container = container;
            parentItem->button = createButton();
            m_buttonToItem[parentItem->button] = parentItem;
            QObject::connect(parentItem->button, &QAbstractButton::toggled,
                             q_ptr, [this](bool checked) { slotToggled(checked); });
            parentItem->layout = new QGridLayout();
            container->setLayout(parentItem->layout);
            if (parentItem->label) {
                l->removeWidget(parentItem->label);
                delete parentItem->label;
                parentItem->label = nullptr;
            }
            int span = 1;
            if (!parentItem->widget && !parentItem->widgetLabel)
                span = 2;
            l->addWidget(parentItem->button, oldRow, 0, 1, span);
            updateItem(parentItem);
        }
        layout = parentItem->layout;
        parentWidget = parentItem->container;
    }

    newItem->label = new QLabel(parentWidget);
    newItem->label->setSizePolicy(QSizePolicy(QSizePolicy::Fixed, QSizePolicy::Fixed));
    newItem->widget = createEditor(index->property(), parentWidget);
    if (newItem->widget) {
        QObject::connect(newItem->widget, &QWidget::destroyed,
                         q_ptr, [this] { slotEditorDestroyed(); });
        m_widgetToItem[newItem->widget] = newItem;
    } else if (index->property()->hasValue()) {
        newItem->widgetLabel = new QLabel(parentWidget);
        newItem->widgetLabel->setSizePolicy(QSizePolicy(QSizePolicy::Ignored, QSizePolicy::Fixed));
    }

    insertRow(layout, row);
    int span = 1;
    if (newItem->widget)
        layout->addWidget(newItem->widget, row, 1);
    else if (newItem->widgetLabel)
        layout->addWidget(newItem->widgetLabel, row, 1);
    else
        span = 2;
    layout->addWidget(newItem->label, row, 0, span, 1);

    m_itemToIndex[newItem] = index;
    m_indexToItem[index] = newItem;

    updateItem(newItem);
}

void QtButtonPropertyBrowserPrivate::propertyRemoved(QtBrowserItem *index)
{
    WidgetItem *item = m_indexToItem.value(index);

    m_indexToItem.remove(index);
    m_itemToIndex.remove(item);

    WidgetItem *parentItem = item->parent;

    const int row = gridRow(item);

    if (parentItem)
        parentItem->children.removeAt(parentItem->children.indexOf(item));
    else
        m_children.removeAt(m_children.indexOf(item));

    const int colSpan = gridSpan(item);

    m_buttonToItem.remove(item->button);

    delete item->widget;
    delete item->label;
    delete item->widgetLabel;
    delete item->button;
    delete item->container;

    if (!parentItem) {
        removeRow(m_mainLayout, row);
        if (colSpan > 1)
            removeRow(m_mainLayout, row);
    } else if (!parentItem->children.empty()) {
        removeRow(parentItem->layout, row);
        if (colSpan > 1)
            removeRow(parentItem->layout, row);
    } else {
        const WidgetItem *grandParent = parentItem->parent;
        QGridLayout *l = nullptr;
        if (grandParent) {
            l = grandParent->layout;
        } else {
            l = m_mainLayout;
        }

        const int parentRow = gridRow(parentItem);
        const int parentSpan = gridSpan(parentItem);

        l->removeWidget(parentItem->button);
        l->removeWidget(parentItem->container);
        delete parentItem->button;
        delete parentItem->container;
        parentItem->button = nullptr;
        parentItem->container = nullptr;
        parentItem->layout = nullptr;
        if (!m_recreateQueue.contains(parentItem))
            m_recreateQueue.append(parentItem);
        if (parentSpan > 1)
            removeRow(l, parentRow + 1);

        updateLater();
    }
    m_recreateQueue.removeAll(item);

    delete item;
}

void QtButtonPropertyBrowserPrivate::insertRow(QGridLayout *layout, int row)
{
    QHash<QLayoutItem *, QRect> itemToPos;
    int idx = 0;
    while (idx < layout->count()) {
        int r, c, rs, cs;
        layout->getItemPosition(idx, &r, &c, &rs, &cs);
        if (r >= row) {
            itemToPos[layout->takeAt(idx)] = QRect(r + 1, c, rs, cs);
        } else {
            idx++;
        }
    }

    for (auto it = itemToPos.constBegin(), icend = itemToPos.constEnd(); it != icend; ++it) {
        const QRect r = it.value();
        layout->addItem(it.key(), r.x(), r.y(), r.width(), r.height());
    }
}

void QtButtonPropertyBrowserPrivate::removeRow(QGridLayout *layout, int row)
{
    QHash<QLayoutItem *, QRect> itemToPos;
    int idx = 0;
    while (idx < layout->count()) {
        int r, c, rs, cs;
        layout->getItemPosition(idx, &r, &c, &rs, &cs);
        if (r > row) {
            itemToPos[layout->takeAt(idx)] = QRect(r - 1, c, rs, cs);
        } else {
            idx++;
        }
    }

    for (auto it = itemToPos.constBegin(), icend = itemToPos.constEnd(); it != icend; ++it) {
        const QRect r = it.value();
        layout->addItem(it.key(), r.x(), r.y(), r.width(), r.height());
    }
}

void QtButtonPropertyBrowserPrivate::propertyChanged(QtBrowserItem *index)
{
    WidgetItem *item = m_indexToItem.value(index);

    updateItem(item);
}

void QtButtonPropertyBrowserPrivate::updateItem(WidgetItem *item)
{
    QtProperty *property = m_itemToIndex[item]->property();
    if (item->button) {
        QFont font = item->button->font();
        font.setUnderline(property->isModified());
        item->button->setFont(font);
        item->button->setText(property->propertyName());
        item->button->setToolTip(property->descriptionToolTip());
        item->button->setStatusTip(property->statusTip());
        item->button->setWhatsThis(property->whatsThis());
        item->button->setEnabled(property->isEnabled());
    }
    if (item->label) {
        QFont font = item->label->font();
        font.setUnderline(property->isModified());
        item->label->setFont(font);
        item->label->setText(property->propertyName());
        item->label->setToolTip(property->descriptionToolTip());
        item->label->setStatusTip(property->statusTip());
        item->label->setWhatsThis(property->whatsThis());
        item->label->setEnabled(property->isEnabled());
    }
    if (item->widgetLabel) {
        QFont font = item->widgetLabel->font();
        font.setUnderline(false);
        item->widgetLabel->setFont(font);
        item->widgetLabel->setText(property->valueText());
        item->widgetLabel->setToolTip(property->valueText());
        item->widgetLabel->setEnabled(property->isEnabled());
    }
    if (item->widget) {
        QFont font = item->widget->font();
        font.setUnderline(false);
        item->widget->setFont(font);
        item->widget->setEnabled(property->isEnabled());
        const QString valueToolTip = property->valueToolTip();
        item->widget->setToolTip(valueToolTip.isEmpty() ? property->valueText() : valueToolTip);
    }
}



/*!
    \class QtButtonPropertyBrowser
    \internal
    \inmodule QtDesigner
    \since 4.4

    \brief The QtButtonPropertyBrowser class provides a drop down QToolButton
    based property browser.

    A property browser is a widget that enables the user to edit a
    given set of properties. Each property is represented by a label
    specifying the property's name, and an editing widget (e.g. a line
    edit or a combobox) holding its value. A property can have zero or
    more subproperties.

    QtButtonPropertyBrowser provides drop down button for all nested
    properties, i.e. subproperties are enclosed by a container associated with
    the drop down button. The parent property's name is displayed as button text. For example:

    \image qtbuttonpropertybrowser.png

    Use the QtAbstractPropertyBrowser API to add, insert and remove
    properties from an instance of the QtButtonPropertyBrowser
    class. The properties themselves are created and managed by
    implementations of the QtAbstractPropertyManager class.

    \sa QtTreePropertyBrowser, QtAbstractPropertyBrowser
*/

/*!
    \fn void QtButtonPropertyBrowser::collapsed(QtBrowserItem *item)

    This signal is emitted when the \a item is collapsed.

    \sa expanded(), setExpanded()
*/

/*!
    \fn void QtButtonPropertyBrowser::expanded(QtBrowserItem *item)

    This signal is emitted when the \a item is expanded.

    \sa collapsed(), setExpanded()
*/

/*!
    Creates a property browser with the given \a parent.
*/
QtButtonPropertyBrowser::QtButtonPropertyBrowser(QWidget *parent)
    : QtAbstractPropertyBrowser(parent), d_ptr(new QtButtonPropertyBrowserPrivate)
{
    d_ptr->q_ptr = this;

    d_ptr->init(this);
}

/*!
    Destroys this property browser.

    Note that the properties that were inserted into this browser are
    \e not destroyed since they may still be used in other
    browsers. The properties are owned by the manager that created
    them.

    \sa QtProperty, QtAbstractPropertyManager
*/
QtButtonPropertyBrowser::~QtButtonPropertyBrowser()
{
    for (auto it = d_ptr->m_itemToIndex.cbegin(), icend = d_ptr->m_itemToIndex.cend(); it != icend; ++it)
        delete it.key();
}

/*!
    \reimp
*/
void QtButtonPropertyBrowser::itemInserted(QtBrowserItem *item, QtBrowserItem *afterItem)
{
    d_ptr->propertyInserted(item, afterItem);
}

/*!
    \reimp
*/
void QtButtonPropertyBrowser::itemRemoved(QtBrowserItem *item)
{
    d_ptr->propertyRemoved(item);
}

/*!
    \reimp
*/
void QtButtonPropertyBrowser::itemChanged(QtBrowserItem *item)
{
    d_ptr->propertyChanged(item);
}

/*!
    Sets the \a item to either collapse or expanded, depending on the value of \a expanded.

    \sa isExpanded(), expanded(), collapsed()
*/

void QtButtonPropertyBrowser::setExpanded(QtBrowserItem *item, bool expanded)
{
    QtButtonPropertyBrowserPrivate::WidgetItem *itm = d_ptr->m_indexToItem.value(item);
    if (itm)
        d_ptr->setExpanded(itm, expanded);
}

/*!
    Returns true if the \a item is expanded; otherwise returns false.

    \sa setExpanded()
*/

bool QtButtonPropertyBrowser::isExpanded(QtBrowserItem *item) const
{
    QtButtonPropertyBrowserPrivate::WidgetItem *itm = d_ptr->m_indexToItem.value(item);
    if (itm)
        return itm->expanded;
    return false;
}

QT_END_NAMESPACE

#include "moc_qtbuttonpropertybrowser_p.cpp"
