// 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 <AppKit/AppKit.h>

#include <QtCore/qtimer.h>
#include <QtGui/qfontdatabase.h>
#include <qpa/qplatformtheme.h>

#include <private/qfont_p.h>
#include <private/qfontengine_p.h>
#include <private/qfontengine_coretext_p.h>

#include "qcocoafontdialoghelper.h"
#include "qcocoahelpers.h"
#include "qcocoaeventdispatcher.h"

#if !CGFLOAT_DEFINED
typedef float CGFloat;  // Should only not be defined on 32-bit platforms
#endif

QT_USE_NAMESPACE

static QFont qfontForCocoaFont(NSFont *cocoaFont, const QFont &resolveFont)
{
    QFont newFont;
    if (cocoaFont) {
        int pSize = qRound([cocoaFont pointSize]);
        QCFType<CTFontDescriptorRef> font(CTFontCopyFontDescriptor((CTFontRef)cocoaFont));
        QString family(QCFString((CFStringRef)CTFontDescriptorCopyAttribute(font, kCTFontFamilyNameAttribute)));
        QString style(QCFString(((CFStringRef)CTFontDescriptorCopyAttribute(font, kCTFontStyleNameAttribute))));

        newFont = QFontDatabase::font(family, style, pSize);
        newFont.setUnderline(resolveFont.underline());
        newFont.setStrikeOut(resolveFont.strikeOut());
    }
    return newFont;
}

@interface QT_MANGLE_NAMESPACE(QNSFontPanelDelegate) : NSObject<NSWindowDelegate, QNSPanelDelegate>
- (void)restoreOriginalContentView;
- (void)updateQtFont;
- (void)changeFont:(id)sender;
- (void)finishOffWithCode:(NSInteger)code;
@end

QT_NAMESPACE_ALIAS_OBJC_CLASS(QNSFontPanelDelegate);

@implementation QNSFontPanelDelegate {
    @public
    NSFontPanel *mFontPanel;
    QCocoaFontDialogHelper *mHelper;
    NSView *mStolenContentView;
    QNSPanelContentsWrapper *mPanelButtons;
    QFont mQtFont;
    NSInteger mResultCode;
    BOOL mDialogIsExecuting;
    BOOL mResultSet;
}

- (instancetype)init
{
    if ((self = [super init])) {
        mFontPanel = [NSFontPanel sharedFontPanel];
        mHelper = nullptr;
        mStolenContentView = nil;
        mPanelButtons = nil;
        mResultCode = NSModalResponseCancel;
        mDialogIsExecuting = false;
        mResultSet = false;

        [mFontPanel setRestorable:NO];
        [mFontPanel setDelegate:self];

        [mFontPanel retain];
    }
    return self;
}

- (void)dealloc
{
    [mStolenContentView release];
    [mFontPanel setDelegate:nil];
    [[NSNotificationCenter defaultCenter] removeObserver:self];

    [super dealloc];
}

- (void)setDialogHelper:(QCocoaFontDialogHelper *)helper
{
    mHelper = helper;

    [mFontPanel setTitle:helper->options()->windowTitle().toNSString()];

    if (mHelper->options()->testOption(QFontDialogOptions::NoButtons)) {
        [self restoreOriginalContentView];
    } else if (!mStolenContentView) {
        // steal the font panel's contents view
        mStolenContentView = mFontPanel.contentView;
        [mStolenContentView retain];
        mFontPanel.contentView = nil;

        // create a new content view and add the stolen one as a subview
        mPanelButtons = [[QNSPanelContentsWrapper alloc] initWithPanelDelegate:self];
        [mPanelButtons addSubview:mStolenContentView];
        mPanelButtons.panelContentsMargins = NSEdgeInsetsMake(0, 0, 7, 0);
        mFontPanel.contentView = mPanelButtons;
        mFontPanel.defaultButtonCell = mPanelButtons.okButton.cell;
    }
}

- (void)closePanel
{
    [mFontPanel close];
}

- (void)restoreOriginalContentView
{
    if (mStolenContentView) {
        // return stolen stuff to its rightful owner
        [mStolenContentView removeFromSuperview];
        [mFontPanel setContentView:mStolenContentView];
        mStolenContentView = nil;
        [mPanelButtons release];
        mPanelButtons = nil;
    }
}

- (void)onOkClicked
{
    [mFontPanel close];
    [self finishOffWithCode:NSModalResponseOK];
}

- (void)onCancelClicked
{
    if (mPanelButtons) {
        [mFontPanel close];
        mQtFont = QFont();
        [self finishOffWithCode:NSModalResponseCancel];
    }
}

- (void)changeFont:(id)sender
{
    Q_UNUSED(sender);
    [self updateQtFont];
}

- (void)updateQtFont
{
    // Get selected font
    NSFontManager *fontManager = [NSFontManager sharedFontManager];
    NSFont *selectedFont = [fontManager selectedFont];
    if (!selectedFont) {
        selectedFont = [NSFont systemFontOfSize:[NSFont systemFontSize]];
    }
    NSFont *panelFont = [fontManager convertFont:selectedFont];
    mQtFont = qfontForCocoaFont(panelFont, mQtFont);

    if (mHelper)
        emit mHelper->currentFontChanged(mQtFont);
}

- (void)showModelessPanel
{
    mDialogIsExecuting = false;
    mResultSet = false;
    // Make this an asynchronous call, so the panel is made key only
    // in the next event loop run. This is to make sure that by
    // the time the modal loop is run in runModalForWindow below,
    // which internally also sets the panel to key window,
    // the panel is not yet key, and the NSApp still has the right
    // reference to the _previousKeyWindow. Otherwise both NSApp.key
    // and NSApp._previousKeyWindow would wrongly point to the panel,
    // loosing any reference to the window that was key before.
    dispatch_async(dispatch_get_main_queue(), ^{
        [mFontPanel makeKeyAndOrderFront:mFontPanel];
    });
}

- (BOOL)runApplicationModalPanel
{
    mDialogIsExecuting = true;
    // Call processEvents in case the event dispatcher has been interrupted, and needs to do
    // cleanup of modal sessions. Do this before showing the native dialog, otherwise it will
    // close down during the cleanup.
    qApp->processEvents(QEventLoop::ExcludeUserInputEvents | QEventLoop::ExcludeSocketNotifiers);

    // Make sure we don't interrupt the runModalForWindow call.
    QCocoaEventDispatcher::clearCurrentThreadCocoaEventDispatcherInterruptFlag();

    [NSApp runModalForWindow:mFontPanel];
    mDialogIsExecuting = false;

    // Wake up the event dispatcher so it can check whether the
    // current event loop should continue spinning or not.
    QCoreApplication::eventDispatcher()->wakeUp();

    return (mResultCode == NSModalResponseOK);
}

// Future proofing in case _NSTargetForSendAction checks this
// property before sending us the changeFont: message.
- (BOOL)worksWhenModal
{
    return YES;
}

- (QPlatformDialogHelper::DialogCode)dialogResultCode
{
    return (mResultCode == NSModalResponseOK) ? QPlatformDialogHelper::Accepted : QPlatformDialogHelper::Rejected;
}

- (BOOL)windowShouldClose:(id)window
{
    Q_UNUSED(window);
    if (!mPanelButtons)
        [self updateQtFont];
    if (mDialogIsExecuting) {
        [self finishOffWithCode:NSModalResponseCancel];
    } else {
        mResultSet = true;
        if (mHelper)
            emit mHelper->reject();
    }
    return true;
}

- (void)finishOffWithCode:(NSInteger)code
{
    mResultCode = code;
    if (mDialogIsExecuting) {
        // We stop the current modal event loop. The control
        // will then return inside -(void)exec below.
        // It's important that the modal event loop is stopped before
        // we accept/reject QFontDialog, since QFontDialog has its
        // own event loop that needs to be stopped last.
        [NSApp stopModalWithCode:code];
    } else {
        // Since we are not in a modal event loop, we can safely close
        // down QFontDialog
        // Calling accept() or reject() can in turn call closeCocoaFontPanel.
        // This check will prevent any such recursion.
        if (!mResultSet) {
            mResultSet = true;
            if (mResultCode == NSModalResponseCancel) {
                emit mHelper->reject();
            } else {
                emit mHelper->accept();
            }
        }
    }
}

@end

QT_BEGIN_NAMESPACE

class QCocoaFontPanel
{
public:
    QCocoaFontPanel()
    {
        mDelegate = [[QNSFontPanelDelegate alloc] init];
    }

    ~QCocoaFontPanel()
    {
        [mDelegate release];
    }

    void init(QCocoaFontDialogHelper *helper)
    {
        [mDelegate setDialogHelper:helper];
    }

    void cleanup(QCocoaFontDialogHelper *helper)
    {
        if (mDelegate->mHelper == helper)
            mDelegate->mHelper = nullptr;
    }

    bool exec()
    {
        // Note: If NSApp is not running (which is the case if e.g a top-most
        // QEventLoop has been interrupted, and the second-most event loop has not
        // yet been reactivated (regardless if [NSApp run] is still on the stack)),
        // showing a native modal dialog will fail.
        return [mDelegate runApplicationModalPanel];
    }

    bool show(Qt::WindowModality windowModality, QWindow *parent)
    {
        Q_UNUSED(parent);
        if (windowModality != Qt::ApplicationModal)
            [mDelegate showModelessPanel];
        // no need to show a Qt::ApplicationModal dialog here, because it will be shown in runApplicationModalPanel
        return true;
    }

    void hide()
    {
        [mDelegate closePanel];
    }

    QFont currentFont() const
    {
        return mDelegate->mQtFont;
    }

    void setCurrentFont(const QFont &font)
    {
        NSFontManager *mgr = [NSFontManager sharedFontManager];
        NSFont *nsFont = nil;

        int weight = 5;
        NSFontTraitMask mask = 0;
        if (font.style() == QFont::StyleItalic) {
            mask |= NSItalicFontMask;
        }
        if (font.weight() == QFont::Bold) {
            weight = 9;
            mask |= NSBoldFontMask;
        }

        QFontInfo fontInfo(font);
        nsFont = [mgr fontWithFamily:fontInfo.family().toNSString()
            traits:mask
            weight:weight
            size:fontInfo.pointSize()];

        [mgr setSelectedFont:nsFont isMultiple:NO];
        mDelegate->mQtFont = font;
    }

private:
    QNSFontPanelDelegate *mDelegate;
};

Q_GLOBAL_STATIC(QCocoaFontPanel, sharedFontPanel)

QCocoaFontDialogHelper::QCocoaFontDialogHelper()
{
}

QCocoaFontDialogHelper::~QCocoaFontDialogHelper()
{
    sharedFontPanel()->cleanup(this);
}

void QCocoaFontDialogHelper::exec()
{
    if (sharedFontPanel()->exec())
        emit accept();
    else
        emit reject();
}

bool QCocoaFontDialogHelper::show(Qt::WindowFlags, Qt::WindowModality windowModality, QWindow *parent)
{
    if (windowModality == Qt::ApplicationModal)
        windowModality = Qt::WindowModal;
    sharedFontPanel()->init(this);
    return sharedFontPanel()->show(windowModality, parent);
}

void QCocoaFontDialogHelper::hide()
{
    sharedFontPanel()->hide();
}

void QCocoaFontDialogHelper::setCurrentFont(const QFont &font)
{
    sharedFontPanel()->init(this);
    sharedFontPanel()->setCurrentFont(font);
}

QFont QCocoaFontDialogHelper::currentFont() const
{
    return sharedFontPanel()->currentFont();
}

QT_END_NAMESPACE