//
//  main.m
//  vsyncanalysis
//
//  Created by Alexandre Janniaux on 27/10/2021.
//

#include <TargetConditionals.h>

#if TARGET_OS_OSX
#import <AppKit/AppKit.h>
#else
#import <UIKit/UIKit.h>
#endif
#import "AppDelegate.h"

//
//  ViewController.m
//  vsyncanalysis
//
//  Created by Alexandre Janniaux on 27/10/2021.
//
//#define USE_OPENGL_ES
#ifdef USE_OPENGL_ES
#import <OpenGLES/EAGL.h>
#import <OpenGLES/ES2/gl.h>
#import <OpenGLES/ES2/glext.h>
#import <QuartzCore/QuartzCore.h>
#endif

#import <AVFoundation/AVFoundation.h>
#import <AVKit/AVKit.h>

#if TARGET_OS_IPHONE
#define VIEW_TYPE UIView
#else
#define VIEW_TYPE NSView
#endif
/*
@interface GLWindow : UIView {
    CAEAGLLayer *_layer;
}
@end
 */

@interface PIPWindow : VIEW_TYPE
@end

@implementation PIPWindow : VIEW_TYPE
+ (Class)layerClass {
    return [AVSampleBufferDisplayLayer class];
}
- (CALayer *)makeBackingLayer {
    return [[AVSampleBufferDisplayLayer alloc] init];
}
@end

#if 0
@implementation GLWindow
+ (Class)layerClass {
    return [CAEAGLLayer class];
}
@end
#endif

#if TARGET_OS_IPHONE
#define RESPONDER UIResponder
#define APPLICATIONDELEGATE UIApplicationDelegate
#else
#define RESPONDER NSResponder
#define APPLICATIONDELEGATE NSApplicationDelegate
#endif


@interface AppDelegate : RESPONDER <APPLICATIONDELEGATE, AVPictureInPictureSampleBufferPlaybackDelegate, AVPictureInPictureControllerDelegate> {
    PIPWindow *_pip;
    
#ifdef USE_OPENGL_ES
    //GLWindow *_view;
    EAGLContext *_context;
    CAEAGLLayer *_eagllayer;
#endif
    
#if TARGET_OS_OSX
    NSWindow *_window;
    NSGestureRecognizer *_tap;
#else
    CADisplayLink *_displayLink;
    UIButton *_pipButton;
    UIWindow *_window;
    UITapGestureRecognizer *_tap;
#endif
    
    AVPictureInPictureController *_pipCtrl;
    AVPictureInPictureControllerContentSource *_pipSource;
    AVSampleBufferDisplayLayer *_pipLayer;

    GLuint _framebuffer;
    GLuint _renderbuffer;

    CFTimeInterval _lastRender;

    const char *_renderMode, *_dropMode;

    long long unsigned _frameNo;
}
- (void)setup;
@end

@implementation AppDelegate

- (void)enablePip:(id)sender {
    NSLog(@"ENABLE PIP");
    //AVPictureInPictureControllerContentSource *source = [[AVPictureInPictureControllerContentSource alloc] initWithSampleBufferDisplayLayer:_pipLayer playbackDelegate:self];
    [_pipCtrl startPictureInPicture];
    //[_pipCtrl setContentSource:source];
}

#if TARGET_OS_OSX
- (void)applicationDidFinishLaunching:(NSNotification *)notification {}

- (void)setup {
#else
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
    // Do any additional setup after loading the view.

    AVAudioSession * audioSession = [AVAudioSession sharedInstance];
    [audioSession setCategory:AVAudioSessionCategoryPlayback error:nil];
#endif

#if TARGET_OS_OSX
    NSRect frame = NSMakeRect(0, 0, 200, 200);
    NSWindow* window  = [[NSWindow alloc] initWithContentRect:frame
                        styleMask:NSWindowStyleMaskResizable
                        backing:NSBackingStoreBuffered
                        defer:NO];
    [window setBackgroundColor:[NSColor blueColor]];
    _window = window;
#else
    _window = [[UIWindow alloc] initWithFrame:UIScreen.mainScreen.bounds];
    _window.rootViewController = [[UIViewController alloc] init];
    _window.backgroundColor = [UIColor blackColor];

#endif
    _pipLayer = [[AVSampleBufferDisplayLayer alloc] init];
    _pipLayer.frame = _window.frame;
    _pip = [[PIPWindow alloc] initWithFrame:_window.frame];
    _pip.userInteractionEnabled = NO;
#if TARGET_OS_OSX
    _pip.wantsLayer = YES;
#endif
    
    assert([AVPictureInPictureController isPictureInPictureSupported]);
    //assert([[_pip layer] isKindOfClass:[AVSampleBufferDisplayLayer class]]);
    AVSampleBufferDisplayLayer *pipLayer = _pip.layer; //_pipLayer;// [_pip layer];
    assert(pipLayer);
    
    _pipSource = [[AVPictureInPictureControllerContentSource alloc] initWithSampleBufferDisplayLayer:pipLayer playbackDelegate:self];
    

    _pipCtrl = [[AVPictureInPictureController alloc] initWithContentSource:_pipSource];
    _pipCtrl.delegate = self;
    assert(_pipCtrl);
    
#if 0
    _pipButton = [UIButton buttonWithType:UIButtonTypeSystem];
    _pipButton.frame = CGRectMake(0, 0, 50, 50);
    _pipButton.backgroundColor = [UIColor whiteColor];
    [_pipButton setTitle:@"PIP" forState:UIControlStateNormal];
    UIImage* startImage = [AVPictureInPictureController pictureInPictureButtonStartImage];
    UIImage* stopImage = [AVPictureInPictureController pictureInPictureButtonStopImage];
    
    [_pipButton setImage:startImage forState:UIControlStateNormal];
    [_pipButton setImage:stopImage forState:UIControlStateSelected];
    [_pipButton addTarget:self action:@selector(enablePip:) forControlEvents:UIControlEventTouchUpInside];
    //[_pipButton setUserInteractionEnabled:YES];
    //[_pipButton setEnabled:YES];
    
    [_window addSubview:_pipButton];
    [_window bringSubviewToFront:_pipButton];
#endif

#if TARGET_OS_IPHONE
    _tap = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(enablePip:)];
    [_window addGestureRecognizer:_tap];
    [_tap setEnabled:YES];
    
    //[_pip.layer addSublayer:_pipLayer];
#ifdef USE_OPENGL_ES
    [_pipLayer addSublayer:_eagllayer];
#endif
    [_window addSubview:_pip];
    [_window makeKeyAndVisible];
#else
    [_window setContentView:_pip];
    [_window makeKeyAndOrderFront:NSApp];
#endif

    
#ifdef USE_OPENGL_ES
    _eagllayer = [[CAEAGLLayer alloc] init];
    _eagllayer.frame = _pip.frame;

    _context = [[EAGLContext alloc] initWithAPI:kEAGLRenderingAPIOpenGLES3];

    EAGLContext *previous = [EAGLContext currentContext];
    [EAGLContext setCurrentContext:_context];

    glGenRenderbuffers(1, &_renderbuffer);
    glBindRenderbuffer(GL_RENDERBUFFER, _renderbuffer);

    glGenFramebuffers(1, &_framebuffer);
    glBindFramebuffer(GL_FRAMEBUFFER, _framebuffer);
    glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0,
                              GL_RENDERBUFFER, _renderbuffer);

    [_context renderbufferStorage:GL_RENDERBUFFER
                   fromDrawable:_eagllayer];
    
    
    assert(glCheckFramebufferStatus(GL_FRAMEBUFFER) == GL_FRAMEBUFFER_COMPLETE);
    [EAGLContext setCurrentContext:previous];
#endif
    
    _lastRender = CACurrentMediaTime();
    _frameNo = 0;

    _renderMode = getenv("RENDER_MODE");
    if (_renderMode == NULL)
        _renderMode = "vsync";

    _dropMode = getenv("DROP_MODE");
    if (_dropMode == NULL)
        _dropMode = "once";

    if (!strcmp(_renderMode, "loop"))
    {
        dispatch_async(dispatch_get_main_queue(), ^{
            [self periodicRender];
        });
    }
    else if (!strcmp(_renderMode, "vsync"))
    {
#if TARGET_OS_IPHONE
        _displayLink = [CADisplayLink displayLinkWithTarget:self selector:@selector(onVsync:)];
        [_displayLink addToRunLoop:[NSRunLoop mainRunLoop]
                           forMode:NSRunLoopCommonModes];
#else
        
#endif
    }
    
    //assert([_pipCtrl isPictureInPicturePossible]);
    [_pipCtrl addObserver:self forKeyPath:@"isPictureInPicturePossible"
                  options:NSKeyValueObservingOptionInitial context:(__bridge void *)self];
    [_pipCtrl addObserver:self forKeyPath:@"isPictureInPictureActive"
                  options:NSKeyValueObservingOptionNew context:(__bridge void *)self];

#if TARGET_OS_IPHONE
    return YES;
#endif
}

- (void)observeValueForKeyPath:(NSString *)keyPath
                      ofObject:(id)object
                        change:(NSDictionary *)change
                       context:(void *)context
{
    NSLog(@"Can start PiP: %d", _pipCtrl.isPictureInPicturePossible);
    NSLog(@"Is active PiP: %d", _pipCtrl.isPictureInPictureActive);
    NSLog(@"Is suspended PiP: %d", _pipCtrl.isPictureInPictureSuspended);


}

- (void)periodicRender {
    [self render];
    dispatch_async(dispatch_get_main_queue(), ^{
        [self periodicRender];
    });
}

#if TARGET_OS_IPHONE
- (void)onVsync:(CADisplayLink *)sender {
    [self render];
}
#endif

- (void)render {
    CFTimeInterval begin_context = CACurrentMediaTime();
    
#ifdef USE_OPENGL_ES
    EAGLContext *previous = [EAGLContext currentContext];
    [EAGLContext setCurrentContext:_context];

    CFTimeInterval begin_clear = CACurrentMediaTime();
    glClearColor(cos(begin_context), 0.f, 0.f, 1.f);
    glClear(GL_COLOR_BUFFER_BIT);

    CFTimeInterval begin_present = CACurrentMediaTime();
    [_context presentRenderbuffer:GL_RENDERBUFFER];

    CFTimeInterval begin_release = CACurrentMediaTime();
    [EAGLContext setCurrentContext:previous];

    CFTimeInterval end_render = CACurrentMediaTime();

    if (begin_present - begin_clear > 5. / 1000 || true)
    {
        NSLog(@"RENDER: total=%.3lf   makeCurrent=%.3lf   clear=%.3lf   present=%.3lf   release=%.3lf",
              1000. * (end_render - begin_context),
              1000. * (begin_clear - begin_context),
              1000. * (begin_present - begin_clear),
              1000. * (begin_release - begin_present),
              1000. * (end_render - begin_release));
        NSLog(@"RENDER: FPS=%.3lf", 1.f / (begin_context - _lastRender));
    }
    _lastRender = begin_context;
    _frameNo++;
#endif
    
    CVPixelBufferRef pixelBuffer=NULL;
    CVPixelBufferCreate(kCFAllocatorDefault, 1280, 720, kCVPixelFormatType_32BGRA, NULL, &pixelBuffer);
    CMSampleTimingInfo info = {
        kCMTimeIndefinite,
        kCMTimeZero,
        kCMTimeInvalid};
    
    CVPixelBufferLockBaseAddress(pixelBuffer, 0);
    size_t width = CVPixelBufferGetWidth(pixelBuffer);
    size_t height = CVPixelBufferGetHeight(pixelBuffer);
    UInt32* buffer = (UInt32*)CVPixelBufferGetBaseAddress(pixelBuffer);
    for ( unsigned long i = 0; i < width * height; i++ )
    {
        uint32_t value = (uint32_t)(0xff * fabs(cos(begin_context))) << 16;
        buffer[i] = CFSwapInt32HostToBig(0x00000fff + value);
    }
    CVPixelBufferUnlockBaseAddress(pixelBuffer, 0);
    
    CMFormatDescriptionRef formatDesc=NULL;
    CMVideoFormatDescriptionCreateForImageBuffer(kCFAllocatorDefault, pixelBuffer, &formatDesc);
    CMSampleBufferRef sampleBuffer=NULL;
    CMSampleBufferCreateReadyWithImageBuffer(kCFAllocatorDefault,
                                             pixelBuffer,
                                             formatDesc,
                                             &info,
                                             &sampleBuffer);
    
    CFArrayRef attachments = CMSampleBufferGetSampleAttachmentsArray(sampleBuffer, true);
    CFMutableDictionaryRef dict = (CFMutableDictionaryRef)CFArrayGetValueAtIndex(attachments, 0);
    CFDictionarySetValue(dict, kCMSampleAttachmentKey_DisplayImmediately, kCFBooleanTrue);
    
    //AVPictureInPictureControllerContentSource *source = _pipCtrl.contentSource;
    //AVSampleBufferDisplayLayer *pipLayer = _pipCtrl.pictureInPictureActive ?
    //_pipLayer : _pip.layer;
    //assert([pipLayer status] != AVQueuedSampleBufferRenderingStatusFailed);
    
    AVSampleBufferDisplayLayer *pipLayer = _pip.layer;
    [pipLayer enqueueSampleBuffer:sampleBuffer];
    [_pipLayer enqueueSampleBuffer:sampleBuffer];
    [pipLayer setNeedsDisplay];
    [_pipCtrl invalidatePlaybackState];
    
    
    CFRelease(sampleBuffer);
    CFRelease(formatDesc);
    CFRelease(pixelBuffer);
}

- (void)pictureInPictureController:(nonnull AVPictureInPictureController *)pictureInPictureController didTransitionToRenderSize:(CMVideoDimensions)newRenderSize {

    NSLog(@"RESIZED TO %fx%f", newRenderSize.width, newRenderSize.height);
}

- (void)pictureInPictureController:(nonnull AVPictureInPictureController *)pictureInPictureController setPlaying:(BOOL)playing {
    NSLog(@"PLAYING STATE: %d", playing);
}

- (void)pictureInPictureController:(nonnull AVPictureInPictureController *)pictureInPictureController skipByInterval:(CMTime)skipInterval completionHandler:(nonnull void (^)(void))completionHandler {
    
}

- (BOOL)pictureInPictureControllerIsPlaybackPaused:(nonnull AVPictureInPictureController *)pictureInPictureController {
    //NSLog(@"IS PLAYBACK PAUSED");
    return NO;
}

- (CMTimeRange)pictureInPictureControllerTimeRangeForPlayback:(nonnull AVPictureInPictureController *)pictureInPictureController {
    return CMTimeRangeMake(kCMTimePositiveInfinity, kCMTimeZero);
}

- (void)pictureInPictureControllerPlaybackPaused:(nonnull AVPictureInPictureController *)controller {
   // NSLog(@"PLAYBACK PAUSED");
}

- (CMTimeRange)pictureInPictureControllerPlaybackTimeRange:(nonnull AVPictureInPictureController *)pictureInPictureController
{
    return CMTimeRangeMake(CMTimeMake(CACurrentMediaTime()*1000000, 1000000), CMTimeMake(100000000, 1000000));
}

- (void)pictureInPictureController:(AVPictureInPictureController *)pictureInPictureController
failedToStartPictureInPictureWithError:(NSError *)error
{
    
}

- (void)pictureInPictureControllerWillStartPictureInPicture:(AVPictureInPictureController *)pictureInPictureController
{
}

@end

int main(int argc, char * argv[]) {
    NSString * appDelegateClassName;
    @autoreleasepool {
        // Setup code that might create autoreleased objects goes here.
        appDelegateClassName = NSStringFromClass([AppDelegate class]);
    }
#if TARGET_OS_IPHONE
    return UIApplicationMain(argc, argv, nil, appDelegateClassName);
#else
    AppDelegate *appDelegate = [[AppDelegate alloc] init];
    [appDelegate setup];
    [NSApp setDelegate:appDelegate];
    [NSApp run];
    return NSApplicationMain(argc, argv);
#endif
}