// Copyright (C) 2018 The Qt Company Ltd.
// Copyright (c) 2007-2008, Apple, Inc.
// SPDX-License-Identifier: BSD-3-Clause

#include <AppKit/AppKit.h>

#include "qcocoaapplicationdelegate.h"
#include "qcocoaintegration.h"
#include "qcocoamenubar.h"
#include "qcocoamenu.h"
#include "qcocoamenuloader.h"
#include "qcocoamenuitem.h"
#include "qcocoansmenu.h"
#include "qcocoahelpers.h"

#if QT_CONFIG(sessionmanager)
#  include "qcocoasessionmanager.h"
#endif

#include <qevent.h>
#include <qurl.h>
#include <qdebug.h>
#include <qguiapplication.h>
#include <qpa/qwindowsysteminterface.h>
#include <qwindowdefs.h>

QT_USE_NAMESPACE

@implementation QCocoaApplicationDelegate {
    NSObject <NSApplicationDelegate> *reflectionDelegate;
    bool inLaunch;
}

+ (instancetype)sharedDelegate
{
    static QCocoaApplicationDelegate *shared = nil;
    static dispatch_once_t onceToken;
    dispatch_once(&onceToken, ^{
        shared = [[self alloc] init];
        atexit_b(^{
            [shared release];
            shared = nil;
        });
    });
    return shared;
}

- (instancetype)init
{
    self = [super init];
    if (self) {
        inLaunch = true;
    }
    return self;
}

- (void)dealloc
{
    [_dockMenu release];
    if (reflectionDelegate) {
        [[NSApplication sharedApplication] setDelegate:reflectionDelegate];
        [reflectionDelegate release];
    }
    [[NSNotificationCenter defaultCenter] removeObserver:self];

    [super dealloc];
}

- (NSMenu *)applicationDockMenu:(NSApplication *)sender
{
    Q_UNUSED(sender);
    // Manually invoke the delegate's -menuWillOpen: method.
    // See QTBUG-39604 (and its fix) for details.
    [self.dockMenu.delegate menuWillOpen:self.dockMenu];
    return [[self.dockMenu retain] autorelease];
}

// This function will only be called when NSApp is actually running.
- (NSApplicationTerminateReply)applicationShouldTerminate:(NSApplication *)sender
{
    if ([reflectionDelegate respondsToSelector:_cmd])
        return [reflectionDelegate applicationShouldTerminate:sender];

    if (QGuiApplicationPrivate::instance()->threadData.loadRelaxed()->eventLoops.isEmpty()) {
        // No event loop is executing. This probably means that Qt is used as a plugin,
        // or as a part of a native Cocoa application. In any case it should be fine to
        // terminate now.
        qCDebug(lcQpaApplication) << "No running event loops, terminating now";
        return NSTerminateNow;
    }

#if QT_CONFIG(sessionmanager)
    QCocoaSessionManager *cocoaSessionManager = QCocoaSessionManager::instance();
    cocoaSessionManager->resetCancellation();
    cocoaSessionManager->appCommitData();

    if (cocoaSessionManager->wasCanceled()) {
        qCDebug(lcQpaApplication) << "Session management canceled application termination";
        return NSTerminateCancel;
    }
#endif

    if (!QWindowSystemInterface::handleApplicationTermination<QWindowSystemInterface::SynchronousDelivery>()) {
        qCDebug(lcQpaApplication) << "Application termination canceled";
        return NSTerminateCancel;
    }

    // Even if the application termination was accepted by the application we can't
    // return NSTerminateNow, as that would trigger AppKit to ultimately call exit().
    // We need to ensure that the runloop continues spinning so that we can return
    // from our own event loop back to main(), and exit from there.
    qCDebug(lcQpaApplication) << "Termination accepted, but returning to runloop for exit through main()";
    return NSTerminateCancel;
}

- (void)applicationWillFinishLaunching:(NSNotification *)notification
{
    if ([reflectionDelegate respondsToSelector:_cmd])
        [reflectionDelegate applicationWillFinishLaunching:notification];

    /*
        From the Cocoa documentation: "A good place to install event handlers
        is in the applicationWillFinishLaunching: method of the application
        delegate. At that point, the Application Kit has installed its default
        event handlers, so if you install a handler for one of the same events,
        it will replace the Application Kit version."
    */

    /*
        If Qt is used as a plugin, we let the 3rd party application handle
        events like quit and open file events. Otherwise, if we install our own
        handlers, we easily end up breaking functionality the 3rd party
        application depends on.
     */
    NSAppleEventManager *eventManager = [NSAppleEventManager sharedAppleEventManager];
    [eventManager setEventHandler:self
                      andSelector:@selector(getUrl:withReplyEvent:)
                    forEventClass:kInternetEventClass
                       andEventID:kAEGetURL];
}

// called by QCocoaIntegration's destructor before resetting the application delegate to nil
- (void)removeAppleEventHandlers
{
    NSAppleEventManager *eventManager = [NSAppleEventManager sharedAppleEventManager];
    [eventManager removeEventHandlerForEventClass:kInternetEventClass andEventID:kAEGetURL];
}

- (bool)inLaunch
{
    return inLaunch;
}

- (void)applicationDidFinishLaunching:(NSNotification *)aNotification
{
    if ([reflectionDelegate respondsToSelector:_cmd])
        [reflectionDelegate applicationDidFinishLaunching:aNotification];

    inLaunch = false;

    if (qEnvironmentVariableIsEmpty("QT_MAC_DISABLE_FOREGROUND_APPLICATION_TRANSFORM")) {
        auto currentApplication = NSRunningApplication.currentApplication;
        if (!currentApplication.active) {
            // Move the application to front to avoid launching behind the terminal.
            // Ignoring other apps is necessary (we must ignore the terminal), but makes
            // Qt apps play slightly less nice with other apps when launching from Finder
            // (see the activateIgnoringOtherApps docs). FIXME: Try to distinguish between
            // being non-active here because another application stole activation in the
            // time it took us to launch from Finder, and being non-active because we were
            // launched from Terminal or something that doesn't activate us at all.
            auto frontmostApplication = NSWorkspace.sharedWorkspace.frontmostApplication;
            qCDebug(lcQpaApplication) << "Launched with" << frontmostApplication
                << "as frontmost application. Activating" << currentApplication << "instead.";
            [NSApplication.sharedApplication activateIgnoringOtherApps:YES];
        }

        if (QOperatingSystemVersion::current() >= QOperatingSystemVersion::MacOSSonoma) {
            // Qt windows are typically shown in main(), at which point the application
            // is not active yet. When the application is activated, either externally
            // or via the override above, it will only bring the main and key windows
            // forward, which differs from the behavior if these windows had been shown
            // once the application was already active. To work around this, we explicitly
            // activate the current application again, bringing all windows to the front.
            // We only do this on Sonoma and up, as earlier macOS versions have a bug where
            // the app will deactivate as part of activating, even if it's active app,
            // which in turn results in losing key window status for the key window.
            // FIXME: Consider bringing our windows to the front via orderFront instead,
            // or deferring the orderFront during setVisible until the app is active.
            [currentApplication activateWithOptions:NSApplicationActivateAllWindows];
        }
    }

    QCocoaMenuBar::insertWindowMenu();
}

/*!
    Tells the delegate to open the specified files

    Sent by the system when the user drags a file to the app's icon
    in places like Finder or the Dock, or opens a file via the "Open
    With" menu in Finder.

    These actions can happen when the application is not running,
    in which case the call comes in between willFinishLaunching
    and didFinishLaunching. In this case we don't pass on the
    incoming file paths as file open events, as the paths are
    also part of the command line arguments, and Qt applications
    normally expect to handle file opening via those.

    \note The app must register itself as a handler for each file
    type via the CFBundleDocumentTypes key in the Info.plist.
 */
- (void)application:(NSApplication *)sender openFiles:(NSArray *)filenames
{
    Q_UNUSED(filenames);
    Q_UNUSED(sender);

    for (NSString *fileName in filenames) {
        QString qtFileName = QString::fromNSString(fileName);
        if (inLaunch) {
            // We need to be careful because Cocoa will be nice enough to take
            // command line arguments and send them to us as events. Given the history
            // of Qt Applications, this will result in behavior people don't want, as
            // they might be doing the opening themselves with the command line parsing.
            if (qApp->arguments().contains(qtFileName))
                continue;
        }
        QWindowSystemInterface::handleFileOpenEvent(qtFileName);
        // FIXME: We're supposed to call [NSApp replyToOpenOrPrint:] here, but we
        //  don't know if the open operation succeeded, failed, or was cancelled.
    }

    if ([reflectionDelegate respondsToSelector:_cmd])
        [reflectionDelegate application:sender openFiles:filenames];

}

- (BOOL)applicationShouldTerminateAfterLastWindowClosed:(NSApplication *)sender
{
    if ([reflectionDelegate respondsToSelector:_cmd])
        return [reflectionDelegate applicationShouldTerminateAfterLastWindowClosed:sender];

    return NO; // Someday qApp->quitOnLastWindowClosed(); when QApp and NSApp work closer together.
}

- (void)applicationDidBecomeActive:(NSNotification *)notification
{
    if (QCocoaWindow::s_applicationActivationObserver) {
        [[[NSWorkspace sharedWorkspace] notificationCenter] removeObserver:QCocoaWindow::s_applicationActivationObserver];
        QCocoaWindow::s_applicationActivationObserver = nil;
    }

    if ([reflectionDelegate respondsToSelector:_cmd])
        [reflectionDelegate applicationDidBecomeActive:notification];

    QWindowSystemInterface::handleApplicationStateChanged(Qt::ApplicationActive);

    if (QCocoaWindow::s_windowUnderMouse) {
        QPointF windowPoint;
        QPointF screenPoint;
        QNSView *view = qnsview_cast(QCocoaWindow::s_windowUnderMouse->m_view);
        [view convertFromScreen:[NSEvent mouseLocation] toWindowPoint:&windowPoint andScreenPoint:&screenPoint];
        QWindow *windowUnderMouse = QCocoaWindow::s_windowUnderMouse->window();
        qCInfo(lcQpaMouse) << "Application activated with mouse at" << windowPoint << "; sending" << QEvent::Enter << "to" << windowUnderMouse;
        QWindowSystemInterface::handleEnterEvent(windowUnderMouse, windowPoint, screenPoint);
    }
}

- (void)applicationDidResignActive:(NSNotification *)notification
{
    if ([reflectionDelegate respondsToSelector:_cmd])
        [reflectionDelegate applicationDidResignActive:notification];

    QWindowSystemInterface::handleApplicationStateChanged(Qt::ApplicationInactive);

    if (QCocoaWindow::s_windowUnderMouse) {
        QWindow *windowUnderMouse = QCocoaWindow::s_windowUnderMouse->window();
        qCInfo(lcQpaMouse) << "Application deactivated; sending" << QEvent::Leave << "to" << windowUnderMouse;
        QWindowSystemInterface::handleLeaveEvent(windowUnderMouse);
    }
}

/*!
    Returns a Boolean value that indicates if the app responds
    to reopen AppleEvents.

    These events are sent whenever the Finder reactivates an already
    running application because someone double-clicked it again or used
    the dock to activate it.

    We pass the activation on to Qt, and return YES, to let AppKit
    follow its normal flow.
 */
- (BOOL)applicationShouldHandleReopen:(NSApplication *)theApplication hasVisibleWindows:(BOOL)flag
{
    if ([reflectionDelegate respondsToSelector:_cmd])
        return [reflectionDelegate applicationShouldHandleReopen:theApplication hasVisibleWindows:flag];

    /*
       true to force delivery of the event even if the application state is already active,
       because rapp (handle reopen) events are sent each time the dock icon is clicked regardless
       of the active state of the application or number of visible windows. For example, a browser
       app that has no windows opened would need the event be to delivered even if it was already
       active in order to create a new window as per OS X conventions.
     */
    QWindowSystemInterface::handleApplicationStateChanged(Qt::ApplicationActive, true /*forcePropagate*/);

    return YES;
}

- (void)setReflectionDelegate:(NSObject <NSApplicationDelegate> *)oldDelegate
{
    [oldDelegate retain];
    [reflectionDelegate release];
    reflectionDelegate = oldDelegate;
}

- (NSMethodSignature *)methodSignatureForSelector:(SEL)aSelector
{
    NSMethodSignature *result = [super methodSignatureForSelector:aSelector];
    if (!result && reflectionDelegate) {
        result = [reflectionDelegate methodSignatureForSelector:aSelector];
    }
    return result;
}

- (BOOL)respondsToSelector:(SEL)aSelector
{
    return [super respondsToSelector:aSelector] || [reflectionDelegate respondsToSelector:aSelector];
}

- (void)forwardInvocation:(NSInvocation *)invocation
{
    SEL invocationSelector = [invocation selector];
    if ([reflectionDelegate respondsToSelector:invocationSelector])
        [invocation invokeWithTarget:reflectionDelegate];
    else
        [self doesNotRecognizeSelector:invocationSelector];
}

/*!
    Callback for when the application is asked to pick up a user activity
    from another app (also known as Handoff, which is part of the bigger
    Continuity story for Apple operating systems).

    This is normally managed by two apps by the same vendor explicitly
    initiating a custom NSUserActivity and picking it up in another app
    on the same or another device, which we don't have APIs for.

    This is also how the system supports Universal Links, where a web page
    can deep-link into an app. In this case the app needs to claim and
    validate an associated domain. The resulting link will be delivered
    as a special NSUserActivityTypeBrowsingWeb activity type, which we
    treat as QDesktopServices::handleUrl().

    Finally, for NS/UIDocument based apps (which Qt is not), the system
    automatically handles document hand-off if the application includes
    the NSUbiquitousDocumentUserActivityType key in its Info.plist.
 */
- (BOOL)application:(NSApplication *)application continueUserActivity:(NSUserActivity *)userActivity
          restorationHandler:(void(^)(NSArray<id<NSUserActivityRestoring>> *restorableObjects))restorationHandler
{
    // Check if eg. user has installed an app delegate capable of handling this
    if ([reflectionDelegate respondsToSelector:_cmd]
        && [reflectionDelegate application:application continueUserActivity:userActivity
                         restorationHandler:restorationHandler] == YES) {
        return YES;
    }

    if (!QGuiApplication::instance())
        return NO;

    if ([userActivity.activityType isEqualToString:NSUserActivityTypeBrowsingWeb]) {
        QCocoaIntegration *cocoaIntegration = QCocoaIntegration::instance();
        Q_ASSERT(cocoaIntegration);
        return cocoaIntegration->services()->handleUrl(QUrl::fromNSURL(userActivity.webpageURL));
    }

    return NO;
}

/*!
    Callback for when the app is asked to open custom URL schemes.

    We register a handler for events of type kInternetEventClass with the
    NSAppleEventManager during application start.

    The application must include the schemes in the CFBundleURLTypes
    key of the Info.plist.

    \note This callback is not used for http/https URLs, see
    continueUserActivity above for how we handle that.
 */
- (void)getUrl:(NSAppleEventDescriptor *)event withReplyEvent:(NSAppleEventDescriptor *)replyEvent
{
    Q_UNUSED(replyEvent);

    NSString *urlString = [[event paramDescriptorForKeyword:keyDirectObject] stringValue];
    const QString qurlString = QString::fromNSString(urlString);

    if (event.eventClass == kInternetEventClass && event.eventID == kAEGetURL) {
        // 'GURL' (Get URL) event this application should handle
        if (!QGuiApplication::instance())
            return;
        QCocoaIntegration *cocoaIntegration = QCocoaIntegration::instance();
        Q_ASSERT(cocoaIntegration);
        if (cocoaIntegration->services()->handleUrl(QUrl(qurlString)))
            return;
    }

    // The string we get from the requesting application might not necessarily meet
    // QUrl's requirement for a IDN-compliant host. So if we can't parse into a QUrl,
    // then we pass the string on to the application as the name of a file (and
    // QFileOpenEvent::file is not guaranteed to be the path to a local, open'able
    // file anyway).
    if (const QUrl url(qurlString); url.isValid())
        QWindowSystemInterface::handleFileOpenEvent(url);
    else
        QWindowSystemInterface::handleFileOpenEvent(qurlString);
}

- (BOOL)applicationSupportsSecureRestorableState:(NSApplication *)application
{
    if (@available(macOS 12, *)) {
        if ([reflectionDelegate respondsToSelector:_cmd])
            return [reflectionDelegate applicationSupportsSecureRestorableState:application];
    }

    // We don't support or implement state restorations via the AppKit
    // state restoration APIs, but if we did, we would/should support
    // secure state restoration. This is the default for apps linked
    // against the macOS 14 SDK, but as we target versions below that
    // as well we need to return YES here explicitly to silence a runtime
    // warning.
    return YES;
}

@end

@implementation QCocoaApplicationDelegate (Menus)

- (BOOL)validateMenuItem:(NSMenuItem*)item
{
    qCDebug(lcQpaMenus) << "Validating" << item << "for" << self;

    auto *nativeItem = qt_objc_cast<QCocoaNSMenuItem *>(item);
    if (!nativeItem)
        return item.enabled; // FIXME Test with with Qt as plugin or embedded QWindow.

    auto *platformItem = nativeItem.platformMenuItem;
    if (!platformItem) // Try a bit harder with orphan menu items
        return item.hasSubmenu || (item.enabled && (item.action != @selector(qt_itemFired:)));

    // Menu-holding items are always enabled, as it's conventional in Cocoa
    if (platformItem->menu())
        return YES;

    return platformItem->isEnabled();
}

@end

@implementation QCocoaApplicationDelegate (MenuAPI)

- (void)qt_itemFired:(QCocoaNSMenuItem *)item
{
    qCDebug(lcQpaMenus) << "Activating" << item;

    if (item.hasSubmenu)
        return;

    auto *nativeItem = qt_objc_cast<QCocoaNSMenuItem *>(item);
    Q_ASSERT_X(nativeItem, qPrintable(__FUNCTION__), "Triggered menu item is not a QCocoaNSMenuItem.");
    auto *platformItem = nativeItem.platformMenuItem;
    // Menu-holding items also get a target to play nicely
    // with NSMenuValidation but should not trigger.
    if (!platformItem || platformItem->menu())
        return;

    QGuiApplicationPrivate::modifier_buttons = QAppleKeyMapper::fromCocoaModifiers([NSEvent modifierFlags]);

    static QMetaMethod activatedSignal = QMetaMethod::fromSignal(&QCocoaMenuItem::activated);
    activatedSignal.invoke(platformItem, Qt::QueuedConnection);
}

@end
