/****************************************************************************
**
** Copyright (C) 2012 Klarälvdalens Datakonsult AB, a KDAB Group company, info@kdab.com, author James Turner <james.turner@kdab.com>
** Contact: https://www.qt.io/licensing/
**
** This file is part of the plugins of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:LGPL$
** Commercial License Usage
** Licensees holding valid commercial Qt licenses may use this file in
** accordance with the commercial license agreement provided with the
** Software or, alternatively, in accordance with the terms contained in
** a written agreement between you and The Qt Company. For licensing terms
** and conditions see https://www.qt.io/terms-conditions. For further
** information use the contact form at https://www.qt.io/contact-us.
**
** GNU Lesser General Public License Usage
** Alternatively, this file may be used under the terms of the GNU Lesser
** General Public License version 3 as published by the Free Software
** Foundation and appearing in the file LICENSE.LGPL3 included in the
** packaging of this file. Please review the following information to
** ensure the GNU Lesser General Public License version 3 requirements
** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
**
** GNU General Public License Usage
** Alternatively, this file may be used under the terms of the GNU
** General Public License version 2.0 or (at your option) the GNU General
** Public license version 3 or any later version approved by the KDE Free
** Qt Foundation. The licenses are as published by the Free Software
** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
** included in the packaging of this file. Please review the following
** information to ensure the GNU General Public License requirements will
** be met: https://www.gnu.org/licenses/gpl-2.0.html and
** https://www.gnu.org/licenses/gpl-3.0.html.
**
** $QT_END_LICENSE$
**
****************************************************************************/

#include "qcocoamenu.h"

#include "qcocoahelpers.h"

#include <QtCore/QtDebug>
#include <QtCore/qmetaobject.h>
#include <QtCore/private/qthread_p.h>
#include <QtGui/private/qguiapplication_p.h>
#include "qcocoaapplication.h"
#include "qcocoamenuloader.h"
#include "qcocoamenubar.h"
#include "qcocoawindow.h"
#import "qnsview.h"

QT_BEGIN_NAMESPACE

NSString *qt_mac_removePrivateUnicode(NSString* string)
{
    int len = [string length];
    if (len) {
        QVarLengthArray <unichar, 10> characters(len);
        bool changed = false;
        for (int i = 0; i<len; i++) {
            characters[i] = [string characterAtIndex:i];
            // check if they belong to key codes in private unicode range
            // currently we need to handle only the NSDeleteFunctionKey
            if (characters[i] == NSDeleteFunctionKey) {
                characters[i] = NSDeleteCharacter;
                changed = true;
            }
        }
        if (changed)
            return [NSString stringWithCharacters:characters.data() length:len];
    }
    return string;
}

static inline QCocoaMenuLoader *getMenuLoader()
{
    return [NSApp QT_MANGLE_NAMESPACE(qt_qcocoamenuLoader)];
}

QT_END_NAMESPACE

@interface QT_MANGLE_NAMESPACE(QCocoaMenuDelegate) : NSObject <NSMenuDelegate> {
    QCocoaMenu *m_menu;
}

- (id) initWithMenu:(QCocoaMenu*) m;
- (NSMenuItem *)findItem:(NSMenu *)menu forKey:(NSString *)key forModifiers:(NSUInteger)modifier;

@end

QT_NAMESPACE_ALIAS_OBJC_CLASS(QCocoaMenuDelegate);

@implementation QCocoaMenuDelegate

- (id) initWithMenu:(QCocoaMenu*) m
{
    if ((self = [super init]))
        m_menu = m;

    return self;
}

- (NSInteger)numberOfItemsInMenu:(NSMenu *)menu
{
    Q_ASSERT(m_menu->nsMenu() == menu);
    return menu.numberOfItems;
}

- (BOOL)menu:(NSMenu *)menu updateItem:(NSMenuItem *)item atIndex:(NSInteger)index shouldCancel:(BOOL)shouldCancel
{
    Q_UNUSED(index);
    Q_ASSERT(m_menu->nsMenu() == menu);
    if (shouldCancel) {
        // TODO detach all submenus
        return NO;
    }

    QCocoaMenuItem *menuItem = reinterpret_cast<QCocoaMenuItem *>(item.tag);
    if (m_menu->items().contains(menuItem)) {
        if (QCocoaMenu *itemSubmenu = menuItem->menu())
            itemSubmenu->setAttachedItem(item);
    }
    return YES;
}

- (void)menu:(NSMenu*)menu willHighlightItem:(NSMenuItem*)item
{
    Q_UNUSED(menu);
    if (item && [item tag]) {
        QCocoaMenuItem *cocoaItem = reinterpret_cast<QCocoaMenuItem *>([item tag]);
        cocoaItem->hovered();
    }
}

- (void) menuWillOpen:(NSMenu*)m
{
    Q_UNUSED(m);
    m_menu->setIsOpen(true);
    emit m_menu->aboutToShow();
}

- (void) menuDidClose:(NSMenu*)m
{
    Q_UNUSED(m);
    m_menu->setIsOpen(false);
    // wrong, but it's the best we can do
    emit m_menu->aboutToHide();
}

- (void) itemFired:(NSMenuItem*) item
{
    QCocoaMenuItem *cocoaItem = reinterpret_cast<QCocoaMenuItem *>([item tag]);
    QScopedScopeLevelCounter scopeLevelCounter(QGuiApplicationPrivate::instance()->threadData);
    QGuiApplicationPrivate::modifier_buttons = [QNSView convertKeyModifiers:[NSEvent modifierFlags]];
    static QMetaMethod activatedSignal = QMetaMethod::fromSignal(&QCocoaMenuItem::activated);
    activatedSignal.invoke(cocoaItem, Qt::QueuedConnection);
}

- (BOOL)validateMenuItem:(NSMenuItem*)menuItem
{
    QCocoaMenuItem *cocoaItem = reinterpret_cast<QCocoaMenuItem *>(menuItem.tag);
    if (!cocoaItem)
        return YES;

    return cocoaItem->isEnabled();
}

- (BOOL)menuHasKeyEquivalent:(NSMenu *)menu forEvent:(NSEvent *)event target:(id *)target action:(SEL *)action
{
    /*
       Check if the menu actually has a keysequence defined for this key event.
       If it does, then we will first send the key sequence to the QWidget that has focus
       since (in Qt's eyes) it needs to a chance at the key event first (QEvent::ShortcutOverride).
       If the widget accepts the key event, we then return YES, but set the target and action to be nil,
       which means that the action should not be triggered, and instead dispatch the event ourselves.
       In every other case we return NO, which means that Cocoa can do as it pleases
       (i.e., fire the menu action).
    */

    // Change the private unicode keys to the ones used in setting the "Key Equivalents"
    NSString *characters = qt_mac_removePrivateUnicode([event characters]);
    // Interested only in Shift, Cmd, Ctrl & Alt Keys, so ignoring masks like, Caps lock, Num Lock ...
    const NSUInteger mask = NSShiftKeyMask | NSControlKeyMask | NSCommandKeyMask | NSAlternateKeyMask;
    if (NSMenuItem *menuItem = [self findItem:menu forKey:characters forModifiers:([event modifierFlags] & mask)]) {
        if (!menuItem.target) {
            // This item was modified by QCocoaMenuBar::redirectKnownMenuItemsToFirstResponder
            // and it looks like we're running a modal session for NSOpenPanel/NSSavePanel.
            // QCocoaFileDialogHelper is actually the only place we use this and we run NSOpenPanel modal
            // (modal sheet, window modal, application modal).
            // Whatever the current first responder is, let's give it a chance
            // and do not touch the Qt's focusObject (which is different from some native view
            // having a focus inside NSSave/OpenPanel.
            *target = nil;
            *action = menuItem.action;
            return YES;
        }

        QObject *object = qApp->focusObject();
        if (object) {
            QChar ch;
            int keyCode;
            ulong nativeModifiers = [event modifierFlags];
            Qt::KeyboardModifiers modifiers = [QNSView convertKeyModifiers: nativeModifiers];
            NSString *charactersIgnoringModifiers = [event charactersIgnoringModifiers];
            NSString *characters = [event characters];

            if ([charactersIgnoringModifiers length] > 0) { // convert the first character into a key code
                if ((modifiers & Qt::ControlModifier) && ([characters length] != 0)) {
                    ch = QChar([characters characterAtIndex:0]);
                } else {
                    ch = QChar([charactersIgnoringModifiers characterAtIndex:0]);
                }
                keyCode = qt_mac_cocoaKey2QtKey(ch);
            } else {
                // might be a dead key
                ch = QChar::ReplacementCharacter;
                keyCode = Qt::Key_unknown;
            }

            QKeyEvent accel_ev(QEvent::ShortcutOverride, (keyCode & (~Qt::KeyboardModifierMask)),
                               Qt::KeyboardModifiers(modifiers & Qt::KeyboardModifierMask));
            accel_ev.ignore();
            QCoreApplication::sendEvent(object, &accel_ev);
            if (accel_ev.isAccepted()) {
                [[NSApp keyWindow] sendEvent: event];
                *target = nil;
                *action = nil;
                return YES;
            }
        }
    }
    return NO;
}

- (NSMenuItem *)findItem:(NSMenu *)menu forKey:(NSString *)key forModifiers:(NSUInteger)modifier
{
    for (NSMenuItem *item in [menu itemArray]) {
        if (![item isEnabled] || [item isHidden] || [item isSeparatorItem])
            continue;
        if ([item hasSubmenu]) {
            if (NSMenuItem *nested = [self findItem:[item submenu] forKey:key forModifiers:modifier])
                return nested;
        }

        NSString *menuKey = [item keyEquivalent];
        if (menuKey
            && NSOrderedSame == [menuKey compare:key]
            && modifier == [item keyEquivalentModifierMask])
            return item;
    }
    return nil;
}

@end

QT_BEGIN_NAMESPACE

QCocoaMenu::QCocoaMenu() :
    m_attachedItem(0),
    m_tag(0),
    m_enabled(true),
    m_parentEnabled(true),
    m_visible(true),
    m_isOpen(false)
{
    QMacAutoReleasePool pool;

    m_nativeMenu = [[NSMenu alloc] initWithTitle:@"Untitled"];
    [m_nativeMenu setAutoenablesItems:YES];
    m_nativeMenu.delegate = [[QCocoaMenuDelegate alloc] initWithMenu:this];
}

QCocoaMenu::~QCocoaMenu()
{
    foreach (QCocoaMenuItem *item, m_menuItems) {
        if (item->menuParent() == this)
            item->setMenuParent(0);
    }

    QMacAutoReleasePool pool;
    NSObject *delegate = m_nativeMenu.delegate;
    m_nativeMenu.delegate = nil;
    [delegate release];
    [m_nativeMenu release];
}

void QCocoaMenu::setText(const QString &text)
{
    QMacAutoReleasePool pool;
    QString stripped = qt_mac_removeAmpersandEscapes(text);
    [m_nativeMenu setTitle:QCFString::toNSString(stripped)];
}

void QCocoaMenu::setMinimumWidth(int width)
{
    m_nativeMenu.minimumWidth = width;
}

void QCocoaMenu::setFont(const QFont &font)
{
    if (font.resolve()) {
        NSFont *customMenuFont = [NSFont fontWithName:QCFString::toNSString(font.family())
                                  size:font.pointSize()];
        m_nativeMenu.font = customMenuFont;
    }
}

void QCocoaMenu::insertMenuItem(QPlatformMenuItem *menuItem, QPlatformMenuItem *before)
{
    QMacAutoReleasePool pool;
    QCocoaMenuItem *cocoaItem = static_cast<QCocoaMenuItem *>(menuItem);
    QCocoaMenuItem *beforeItem = static_cast<QCocoaMenuItem *>(before);

    cocoaItem->sync();
    if (beforeItem) {
        int index = m_menuItems.indexOf(beforeItem);
        // if a before item is supplied, it should be in the menu
        if (index < 0) {
            qWarning("Before menu item not found");
            return;
        }
        m_menuItems.insert(index, cocoaItem);
    } else {
        m_menuItems.append(cocoaItem);
    }

    insertNative(cocoaItem, beforeItem);
}

void QCocoaMenu::insertNative(QCocoaMenuItem *item, QCocoaMenuItem *beforeItem)
{
    item->nsItem().target = m_nativeMenu.delegate;
    if (!item->menu())
        [item->nsItem() setAction:@selector(itemFired:)];
    else if (isOpen() && item->nsItem()) // Someone's adding new items after aboutToShow() was emitted
        item->menu()->setAttachedItem(item->nsItem());

    item->setParentEnabled(isEnabled());

    if (item->isMerged())
        return;

    // if the item we're inserting before is merged, skip along until
    // we find a non-merged real item to insert ahead of.
    while (beforeItem && beforeItem->isMerged()) {
        beforeItem = itemOrNull(m_menuItems.indexOf(beforeItem) + 1);
    }

    if (beforeItem) {
        if (beforeItem->isMerged()) {
            qWarning("No non-merged before menu item found");
            return;
        }
        NSUInteger nativeIndex = [m_nativeMenu indexOfItem:beforeItem->nsItem()];
        [m_nativeMenu insertItem: item->nsItem() atIndex: nativeIndex];
    } else {
        [m_nativeMenu addItem: item->nsItem()];
    }
    item->setMenuParent(this);
}

bool QCocoaMenu::isOpen() const
{
    return m_isOpen;
}

void QCocoaMenu::setIsOpen(bool isOpen)
{
    m_isOpen = isOpen;
}

void QCocoaMenu::removeMenuItem(QPlatformMenuItem *menuItem)
{
    QMacAutoReleasePool pool;
    QCocoaMenuItem *cocoaItem = static_cast<QCocoaMenuItem *>(menuItem);
    if (!m_menuItems.contains(cocoaItem)) {
        qWarning("Menu does not contain the item to be removed");
        return;
    }

    if (cocoaItem->menuParent() == this)
        cocoaItem->setMenuParent(0);

    // Ignore any parent enabled state
    cocoaItem->setParentEnabled(true);

    m_menuItems.removeOne(cocoaItem);
    if (!cocoaItem->isMerged()) {
        if (m_nativeMenu != [cocoaItem->nsItem() menu]) {
            qWarning("Item to remove does not belong to this menu");
            return;
        }
        [m_nativeMenu removeItem: cocoaItem->nsItem()];
    }
}

QCocoaMenuItem *QCocoaMenu::itemOrNull(int index) const
{
    if ((index < 0) || (index >= m_menuItems.size()))
        return 0;

    return m_menuItems.at(index);
}

void QCocoaMenu::syncMenuItem(QPlatformMenuItem *menuItem)
{
    QMacAutoReleasePool pool;
    QCocoaMenuItem *cocoaItem = static_cast<QCocoaMenuItem *>(menuItem);
    if (!m_menuItems.contains(cocoaItem)) {
        qWarning("Item does not belong to this menu");
        return;
    }

    bool wasMerged = cocoaItem->isMerged();
    NSMenu *oldMenu = wasMerged ? [getMenuLoader() applicationMenu] : m_nativeMenu;
    NSMenuItem *oldItem = [oldMenu itemWithTag:(NSInteger) cocoaItem];

    if (cocoaItem->sync() != oldItem) {
        // native item was changed for some reason
        if (oldItem) {
            if (wasMerged) {
                [oldItem setEnabled:NO];
                [oldItem setHidden:YES];
            } else {
                [m_nativeMenu removeItem:oldItem];
            }
        }

        QCocoaMenuItem* beforeItem = itemOrNull(m_menuItems.indexOf(cocoaItem) + 1);
        insertNative(cocoaItem, beforeItem);
    }
}

void QCocoaMenu::syncSeparatorsCollapsible(bool enable)
{
    QMacAutoReleasePool pool;
    if (enable) {
        bool previousIsSeparator = true; // setting to true kills all the separators placed at the top.
        NSMenuItem *previousItem = nil;

        NSArray *itemArray = [m_nativeMenu itemArray];
        for (unsigned int i = 0; i < [itemArray count]; ++i) {
            NSMenuItem *item = reinterpret_cast<NSMenuItem *>([itemArray objectAtIndex:i]);
            if ([item isSeparatorItem]) {
                QCocoaMenuItem *cocoaItem = reinterpret_cast<QCocoaMenuItem *>([item tag]);
                if (cocoaItem)
                    cocoaItem->setVisible(!previousIsSeparator);
                [item setHidden:previousIsSeparator];
            }

            if (![item isHidden]) {
                previousItem = item;
                previousIsSeparator = ([previousItem isSeparatorItem]);
            }
        }

        // We now need to check the final item since we don't want any separators at the end of the list.
        if (previousItem && previousIsSeparator) {
            QCocoaMenuItem *cocoaItem = reinterpret_cast<QCocoaMenuItem *>([previousItem tag]);
            if (cocoaItem)
                cocoaItem->setVisible(false);
            [previousItem setHidden:YES];
        }
    } else {
        foreach (QCocoaMenuItem *item, m_menuItems) {
            if (!item->isSeparator())
                continue;

            // sync the visiblity directly
            item->sync();
        }
    }
}

void QCocoaMenu::setEnabled(bool enabled)
{
    if (m_enabled == enabled)
        return;
    m_enabled = enabled;
    const bool wasParentEnabled = m_parentEnabled;
    propagateEnabledState(m_enabled);
    m_parentEnabled = wasParentEnabled; // Reset to the parent value
}

bool QCocoaMenu::isEnabled() const
{
    return m_attachedItem ? [m_attachedItem isEnabled] : m_enabled && m_parentEnabled;
}

void QCocoaMenu::setVisible(bool visible)
{
    m_visible = visible;
}

void QCocoaMenu::showPopup(const QWindow *parentWindow, const QRect &targetRect, const QPlatformMenuItem *item)
{
    QMacAutoReleasePool pool;

    QPoint pos =  QPoint(targetRect.left(), targetRect.top() + targetRect.height());
    QCocoaWindow *cocoaWindow = parentWindow ? static_cast<QCocoaWindow *>(parentWindow->handle()) : 0;
    NSView *view = cocoaWindow ? cocoaWindow->contentView() : nil;
    NSMenuItem *nsItem = item ? ((QCocoaMenuItem *)item)->nsItem() : nil;

    QScreen *screen = 0;
    if (parentWindow)
        screen = parentWindow->screen();
    if (!screen && !QGuiApplication::screens().isEmpty())
        screen = QGuiApplication::screens().at(0);
    Q_ASSERT(screen);

    // Ideally, we would call -popUpMenuPositioningItem:atLocation:inView:.
    // However, this showed not to work with modal windows where the menu items
    // would appear disabled. So, we resort to a more artisanal solution. Note
    // that this implies several things.
    if (nsItem) {
        // If we want to position the menu popup so that a specific item lies under
        // the mouse cursor, we resort to NSPopUpButtonCell to do that. This is the
        // typical use-case for a choice list, or non-editable combobox. We can't
        // re-use the popUpContextMenu:withEvent:forView: logic below since it won't
        // respect the menu's minimum width.
        NSPopUpButtonCell *popupCell = [[[NSPopUpButtonCell alloc] initTextCell:@"" pullsDown:NO]
                                                                   autorelease];
        [popupCell setAltersStateOfSelectedItem:NO];
        [popupCell setTransparent:YES];
        [popupCell setMenu:m_nativeMenu];
        [popupCell selectItem:nsItem];

        int availableHeight = screen->availableSize().height();
        const QPoint &globalPos = parentWindow->mapToGlobal(pos);
        int menuHeight = m_nativeMenu.size.height;
        if (globalPos.y() + menuHeight > availableHeight) {
            // Maybe we need to fix the vertical popup position but we don't know the
            // exact popup height at the moment (and Cocoa is just guessing) nor its
            // position. So, instead of translating by the popup's full height, we need
            // to estimate where the menu will show up and translate by the remaining height.
            float idx = ([m_nativeMenu indexOfItem:nsItem] + 1.0f) / m_nativeMenu.numberOfItems;
            float heightBelowPos = (1.0 - idx) * menuHeight;
            if (globalPos.y() + heightBelowPos > availableHeight)
                pos.setY(pos.y() - globalPos.y() + availableHeight - heightBelowPos);
        }

        NSRect cellFrame = NSMakeRect(pos.x(), pos.y(), m_nativeMenu.minimumWidth, 10);
        [popupCell performClickWithFrame:cellFrame inView:view];
    } else {
        // Else, we need to transform 'pos' to window or screen coordinates.
        NSPoint nsPos = NSMakePoint(pos.x() - 1, pos.y());
        if (view) {
            // convert coordinates from view to the view's window
            nsPos = [view convertPoint:nsPos toView:nil];
        } else {
            nsPos.y = screen->availableVirtualSize().height() - nsPos.y;
        }

        if (view) {
            // Finally, we need to synthesize an event.
            NSEvent *menuEvent = [NSEvent mouseEventWithType:NSRightMouseDown
                                          location:nsPos
                                          modifierFlags:0
                                          timestamp:0
                                          windowNumber:view ? view.window.windowNumber : 0
                                          context:nil
                                          eventNumber:0
                                          clickCount:1
                                          pressure:1.0];
            [NSMenu popUpContextMenu:m_nativeMenu withEvent:menuEvent forView:view];
        } else {
            [m_nativeMenu popUpMenuPositioningItem:nsItem atLocation:nsPos inView:0];
        }
    }

    // The calls above block, and also swallow any mouse release event,
    // so we need to clear any mouse button that triggered the menu popup.
    if ([view isKindOfClass:[QNSView class]])
        [(QNSView *)view resetMouseButtons];
}

void QCocoaMenu::dismiss()
{
    [m_nativeMenu cancelTracking];
}

QPlatformMenuItem *QCocoaMenu::menuItemAt(int position) const
{
    if (0 <= position && position < m_menuItems.count())
        return m_menuItems.at(position);

    return 0;
}

QPlatformMenuItem *QCocoaMenu::menuItemForTag(quintptr tag) const
{
    foreach (QCocoaMenuItem *item, m_menuItems) {
        if (item->tag() ==  tag)
            return item;
    }

    return 0;
}

QList<QCocoaMenuItem *> QCocoaMenu::items() const
{
    return m_menuItems;
}

QList<QCocoaMenuItem *> QCocoaMenu::merged() const
{
    QList<QCocoaMenuItem *> result;
    foreach (QCocoaMenuItem *item, m_menuItems) {
        if (item->menu()) { // recurse into submenus
            result.append(item->menu()->merged());
            continue;
        }

        if (item->isMerged())
            result.append(item);
    }

    return result;
}

void QCocoaMenu::propagateEnabledState(bool enabled)
{
    QMacAutoReleasePool pool; // FIXME Is this still needed for Creator? See 6a0bb4206a2928b83648

    m_parentEnabled = enabled;
    if (!m_enabled && enabled) // Some ancestor was enabled, but this menu is not
        return;

    foreach (QCocoaMenuItem *item, m_menuItems) {
        if (QCocoaMenu *menu = item->menu())
            menu->propagateEnabledState(enabled);
        else
            item->setParentEnabled(enabled);
    }
}

void QCocoaMenu::setAttachedItem(NSMenuItem *item)
{
    if (item == m_attachedItem)
        return;

    if (m_attachedItem)
        m_attachedItem.submenu = nil;

    m_attachedItem = item;

    if (m_attachedItem)
        m_attachedItem.submenu = m_nativeMenu;

}

NSMenuItem *QCocoaMenu::attachedItem() const
{
    return m_attachedItem;
}

QT_END_NAMESPACE
