/*
  Simple DirectMedia Layer
  Copyright (C) 1997-2020 Sam Lantinga <slouken@libsdl.org>

  This software is provided 'as-is', without any express or implied
  warranty.  In no event will the authors be held liable for any damages
  arising from the use of this software.

  Permission is granted to anyone to use this software for any purpose,
  including commercial applications, and to alter it and redistribute it
  freely, subject to the following restrictions:

  1. The origin of this software must not be misrepresented; you must not
     claim that you wrote the original software. If you use this software
     in a product, an acknowledgment in the product documentation would be
     appreciated but is not required.
  2. Altered source versions must be plainly marked as such, and must not be
     misrepresented as being the original software.
  3. This notice may not be removed or altered from any source distribution.
*/
#include "../../SDL_internal.h"

#if SDL_VIDEO_DRIVER_UIKIT

#include "../../events/SDL_events_c.h"

#include "SDL_uikitvideo.h"
#include "SDL_uikitevents.h"
#include "SDL_uikitopengles.h"

#import <Foundation/Foundation.h>

#if (__IPHONE_OS_VERSION_MAX_ALLOWED >= 140000) || (__APPLETV_OS_VERSION_MAX_ALLOWED >= 140000) || (__MAC_OS_VERSION_MAX_ALLOWED > 1500000)
#import <GameController/GameController.h>

#define ENABLE_GCKEYBOARD
#define ENABLE_GCMOUSE
#endif

static BOOL UIKit_EventPumpEnabled = YES;

void
SDL_iPhoneSetEventPump(SDL_bool enabled)
{
    UIKit_EventPumpEnabled = enabled;
}

void
UIKit_PumpEvents(_THIS)
{
    if (!UIKit_EventPumpEnabled) {
        return;
    }

    /* Let the run loop run for a short amount of time: long enough for
       touch events to get processed (which is important to get certain
       elements of Game Center's GKLeaderboardViewController to respond
       to touch input), but not long enough to introduce a significant
       delay in the rest of the app.
    */
    const CFTimeInterval seconds = 0.000002;

    /* Pump most event types. */
    SInt32 result;
    do {
        result = CFRunLoopRunInMode(kCFRunLoopDefaultMode, seconds, TRUE);
    } while (result == kCFRunLoopRunHandledSource);

    /* Make sure UIScrollView objects scroll properly. */
    do {
        result = CFRunLoopRunInMode((CFStringRef)UITrackingRunLoopMode, seconds, TRUE);
    } while(result == kCFRunLoopRunHandledSource);

    /* See the comment in the function definition. */
#if SDL_VIDEO_OPENGL_ES || SDL_VIDEO_OPENGL_ES2
    UIKit_GL_RestoreCurrentContext();
#endif
}

#ifdef ENABLE_GCKEYBOARD

static SDL_bool keyboard_connected = SDL_FALSE;
static id keyboard_connect_observer = nil;
static id keyboard_disconnect_observer = nil;

static void OnGCKeyboardConnected(GCKeyboard *keyboard) API_AVAILABLE(macos(11.0), ios(14.0), tvos(14.0))
{
    keyboard_connected = SDL_TRUE;
    keyboard.keyboardInput.keyChangedHandler = ^(GCKeyboardInput *keyboard, GCControllerButtonInput *key, GCKeyCode keyCode, BOOL pressed)
    {
        SDL_SendKeyboardKey(pressed ? SDL_PRESSED : SDL_RELEASED, (SDL_Scancode)keyCode);
    };

	dispatch_queue_t queue = dispatch_queue_create( "org.libsdl.input.keyboard", DISPATCH_QUEUE_SERIAL );
	dispatch_set_target_queue( queue, dispatch_get_global_queue( DISPATCH_QUEUE_PRIORITY_HIGH, 0 ) );
	keyboard.handlerQueue = queue;
}

static void OnGCKeyboardDisconnected(GCKeyboard *keyboard) API_AVAILABLE(macos(11.0), ios(14.0), tvos(14.0))
{
    keyboard.keyboardInput.keyChangedHandler = nil;
    keyboard_connected = SDL_FALSE;
}

void SDL_InitGCKeyboard(void)
{
    @autoreleasepool {
        if (@available(iOS 14.0, tvOS 14.0, *)) {
            NSNotificationCenter *center = [NSNotificationCenter defaultCenter];

            keyboard_connect_observer = [center addObserverForName:GCKeyboardDidConnectNotification
                                                            object:nil
                                                             queue:nil
                                                        usingBlock:^(NSNotification *note) {
                                                            GCKeyboard *keyboard = note.object;
                                                            OnGCKeyboardConnected(keyboard);
                                                        }];

            keyboard_disconnect_observer = [center addObserverForName:GCKeyboardDidDisconnectNotification
                                                               object:nil
                                                                queue:nil
                                                           usingBlock:^(NSNotification *note) {
                                                                GCKeyboard *keyboard = note.object;
                                                                OnGCKeyboardDisconnected(keyboard);
                                                           }];

            if (GCKeyboard.coalescedKeyboard != nil) {
                OnGCKeyboardConnected(GCKeyboard.coalescedKeyboard);
            }
        }
    }
}

SDL_bool SDL_HasGCKeyboard(void)
{
    return keyboard_connected;
}

void SDL_QuitGCKeyboard(void)
{
    @autoreleasepool {
        if (@available(iOS 14.0, tvOS 14.0, *)) {
            NSNotificationCenter *center = [NSNotificationCenter defaultCenter];

            if (keyboard_connect_observer) {
                [center removeObserver:keyboard_connect_observer name:GCKeyboardDidConnectNotification object:nil];
                keyboard_connect_observer = nil;
            }

            if (keyboard_disconnect_observer) {
                [center removeObserver:keyboard_disconnect_observer name:GCKeyboardDidDisconnectNotification object:nil];
                keyboard_disconnect_observer = nil;
            }

            if (GCKeyboard.coalescedKeyboard != nil) {
                OnGCKeyboardDisconnected(GCKeyboard.coalescedKeyboard);
            }
        }
    }
}

#else

void SDL_InitGCKeyboard(void)
{
}

SDL_bool SDL_HasGCKeyboard(void)
{
    return SDL_FALSE;
}

void SDL_QuitGCKeyboard(void)
{
}

#endif /* ENABLE_GCKEYBOARD */


#ifdef ENABLE_GCMOUSE

static int mice_connected = 0;
static id mouse_connect_observer = nil;
static id mouse_disconnect_observer = nil;

static int SetGCMouseRelativeMode(SDL_bool enabled)
{
    /* We'll always send relative motion and we can't warp, so nothing to do here */
    return 0;
}

static void OnGCMouseButtonChanged(SDL_MouseID mouseID, Uint8 button, BOOL pressed)
{
    SDL_SendMouseButton(SDL_GetMouseFocus(), mouseID, pressed ? SDL_PRESSED : SDL_RELEASED, button);
}

static void OnGCMouseConnected(GCMouse *mouse) API_AVAILABLE(macos(11.0), ios(14.0), tvos(14.0))
{
    SDL_MouseID mouseID = mice_connected;

    mouse.mouseInput.leftButton.pressedChangedHandler = ^(GCControllerButtonInput *button, float value, BOOL pressed)
    {
        OnGCMouseButtonChanged(mouseID, SDL_BUTTON_LEFT, pressed);
    };
    mouse.mouseInput.middleButton.pressedChangedHandler = ^(GCControllerButtonInput *button, float value, BOOL pressed)
    {
        OnGCMouseButtonChanged(mouseID, SDL_BUTTON_MIDDLE, pressed);
    };
    mouse.mouseInput.rightButton.pressedChangedHandler = ^(GCControllerButtonInput *button, float value, BOOL pressed)
    {
        OnGCMouseButtonChanged(mouseID, SDL_BUTTON_RIGHT, pressed);
    };

    int auxiliary_button = SDL_BUTTON_X1;
    for (GCControllerButtonInput *button in mouse.mouseInput.auxiliaryButtons) {
        button.pressedChangedHandler = ^(GCControllerButtonInput *button, float value, BOOL pressed)
        {
            OnGCMouseButtonChanged(mouseID, auxiliary_button, pressed);
        };
        ++auxiliary_button;
    }

    mouse.mouseInput.mouseMovedHandler = ^(GCMouseInput *mouse, float deltaX, float deltaY)
    {
		SDL_SendMouseMotion(SDL_GetMouseFocus(), mouseID, SDL_TRUE, (int)deltaX, -(int)deltaY);
    };

	dispatch_queue_t queue = dispatch_queue_create( "org.libsdl.input.mouse", DISPATCH_QUEUE_SERIAL );
	dispatch_set_target_queue( queue, dispatch_get_global_queue( DISPATCH_QUEUE_PRIORITY_HIGH, 0 ) );
	mouse.handlerQueue = queue;

    ++mice_connected;
}

static void OnGCMouseDisconnected(GCMouse *mouse) API_AVAILABLE(macos(11.0), ios(14.0), tvos(14.0))
{
    --mice_connected;

    mouse.mouseInput.mouseMovedHandler = nil;

    mouse.mouseInput.leftButton.pressedChangedHandler = nil;
    mouse.mouseInput.middleButton.pressedChangedHandler = nil;
    mouse.mouseInput.rightButton.pressedChangedHandler = nil;

    for (GCControllerButtonInput *button in mouse.mouseInput.auxiliaryButtons) {
        button.pressedChangedHandler = nil;
    }
}

void SDL_InitGCMouse(void)
{
	@autoreleasepool {
		/* There is a bug where mouse accumulates duplicate deltas over time in iOS 14.0 */
        if (@available(iOS 14.1, tvOS 14.1, *)) {
            NSNotificationCenter *center = [NSNotificationCenter defaultCenter];

            mouse_connect_observer = [center addObserverForName:GCMouseDidConnectNotification
                                                         object:nil
                                                          queue:nil
                                                     usingBlock:^(NSNotification *note) {
                                                         GCMouse *mouse = note.object;
                                                         OnGCMouseConnected(mouse);
                                                     }];

            mouse_disconnect_observer = [center addObserverForName:GCMouseDidDisconnectNotification
                                                            object:nil
                                                             queue:nil
                                                        usingBlock:^(NSNotification *note) {
                                                            GCMouse *mouse = note.object;
                                                            OnGCMouseDisconnected(mouse);
                                                       }];

            for (GCMouse *mouse in [GCMouse mice]) {
                OnGCMouseConnected(mouse);
            }

            SDL_GetMouse()->SetRelativeMouseMode = SetGCMouseRelativeMode;
        }
    }
}

SDL_bool SDL_HasGCMouse(void)
{
    return (mice_connected > 0);
}

void SDL_QuitGCMouse(void)
{
    @autoreleasepool {
        if (@available(iOS 14.1, tvOS 14.1, *)) {
            NSNotificationCenter *center = [NSNotificationCenter defaultCenter];

            if (mouse_connect_observer) {
                [center removeObserver:mouse_connect_observer name:GCMouseDidConnectNotification object:nil];
                mouse_connect_observer = nil;
            }

            if (mouse_disconnect_observer) {
                [center removeObserver:mouse_disconnect_observer name:GCMouseDidDisconnectNotification object:nil];
                mouse_disconnect_observer = nil;
            }

            for (GCMouse *mouse in [GCMouse mice]) {
                OnGCMouseDisconnected(mouse);
            }

            SDL_GetMouse()->SetRelativeMouseMode = NULL;
        }
    }
}

#else

void SDL_InitGCMouse(void)
{
}

SDL_bool SDL_HasGCMouse(void)
{
    return SDL_FALSE;
}

void SDL_QuitGCMouse(void)
{
}

#endif /* ENABLE_GCMOUSE */

#endif /* SDL_VIDEO_DRIVER_UIKIT */

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