#include "pch.h"
#include "shader.hpp"
#include "shape.hpp"
#include "texture.hpp"
#include "image.hpp"
#include "app.hpp"

#include <CoreFoundation/CoreFoundation.h>
#include <Cocoa/Cocoa.h>
#include <CoreVideo/CoreVideo.h>
#include <OpenGL/OpenGL.h>

@interface View : NSOpenGLView
{
    CVDisplayLinkRef dl;
}
@end @implementation View
- (instancetype)initWithFrame:(NSRect)frameRect
{
    NSOpenGLPixelFormatAttribute attrs[] =
    {
        NSOpenGLPFADoubleBuffer,
        NSOpenGLPFADepthSize, 24,
        // Must specify the 3.2 Core Profile to use OpenGL 3.2
        NSOpenGLPFAOpenGLProfile, NSOpenGLProfileVersion4_1Core,
        // Multisample
        NSOpenGLPFAMultisample,
        NSOpenGLPFASamples, 2,
        NSOpenGLPFASampleBuffers, 1,
        0
    };
    NSOpenGLPixelFormat *pf = [[NSOpenGLPixelFormat alloc] initWithAttributes:attrs];
    NSOpenGLContext* context = [[NSOpenGLContext alloc] initWithFormat:pf shareContext:nil];
    self = [super initWithFrame:frameRect pixelFormat:pf];
    [self setPixelFormat:pf];
    [self setOpenGLContext:context];
    return self;
}
- (void)prepareOpenGL
{
    NSLog(@"prepare");

    // Synchronize buffer swaps with vertical refresh rate
    GLint swapInt = 1;
    [[self openGLContext] setValues:&swapInt forParameter:NSOpenGLCPSwapInterval];
    
    // Create a display link capable of being used with all active displays
    CVDisplayLinkCreateWithActiveCGDisplays(&dl);
    
    // Set the renderer output callback function
    CVDisplayLinkSetOutputCallback(dl, &MyDisplayLinkCallback, (__bridge void*)self);
    
    // Set the display link for the current renderer
    CGLContextObj cglContext = [[self openGLContext] CGLContextObj];
    CGLPixelFormatObj cglPixelFormat = [[self pixelFormat] CGLPixelFormatObj];
    CVDisplayLinkSetCurrentCGDisplayFromOpenGLContext(dl, cglContext, cglPixelFormat);
    
    // Activate the display link
    CVDisplayLinkStart(dl);
    
    CGLEnable([self.openGLContext CGLContextObj], kCGLCECrashOnRemovedFunctions);
    
    App::I.init();
}

// This is the renderer output callback function
static CVReturn MyDisplayLinkCallback(CVDisplayLinkRef displayLink, const CVTimeStamp* now,
    const CVTimeStamp* outputTime, CVOptionFlags flagsIn, CVOptionFlags* flagsOut, void* displayLinkContext)
{
    CVReturn result = [(__bridge View*)displayLinkContext getFrameForTime:outputTime];
    return result;
}

- (CVReturn)getFrameForTime:(const CVTimeStamp*)outputTime
{
    static double _timeFreq = CVGetHostClockFrequency();
    static double _prevTime = (double)outputTime->hostTime / _timeFreq;
    double hostTime = (double)outputTime->hostTime;
    double now = hostTime / _timeFreq;
    
    // this will not update unless 1/30th of a second has passed since the last update
    if ( now < _prevTime + (1.0 / 30.0) )
    {
        // Add your drawing codes here
        [[self openGLContext] makeCurrentContext];

        App::I.update(now - _prevTime);
        
        [[self openGLContext] flushBuffer];
        // returning NO will cause the layer to NOT be redrawn
        return NO;
    }
    else
    {
        // change whatever you want to change here, as a function of time elapsed
        _prevTime = now;
        // return YES to have your layer redrawn
        return YES;
    }
    
    return kCVReturnSuccess;
}

- (void)dealloc
{
    // Release the display link
    CVDisplayLinkRelease(dl);
}

- (void)drawRect:(NSRect)dirtyRect
{
    NSLog(@"drawRect");
}
@end

@interface Window : NSWindow
@end @implementation Window
- (void)keyDown:(NSEvent *)theEvent
{
    [[self windowController] keyDown:theEvent];
}
@end

@interface Controller : NSWindowController
@end @implementation Controller
- (void)keyDown:(NSEvent *)theEvent
{
    unichar c = [[theEvent charactersIgnoringModifiers] characterAtIndex:0];
    if (c == 27)
    {
        [[NSApplication sharedApplication] terminate:nil];
    }
}
@end

@interface AppOSX : NSApplication<NSApplicationDelegate>
{
    Window* window;
    Controller* controller;
    View* view;
}
@end @implementation AppOSX
- (instancetype)init
{
    self = [super init];
    [self setActivationPolicy:NSApplicationActivationPolicyRegular]; // make it to the front
    [self setDelegate:self];
    return self;
}
- (void)applicationDidFinishLaunching:(NSNotification *)notification
{
    auto& app = App::I;
    app.create();
    NSRect r = NSMakeRect(0, 0, app.width, app.height);

    view = [[View alloc] initWithFrame:r];
    
    window = [[Window alloc] initWithContentRect:r
                                       styleMask:NSTitledWindowMask|NSMiniaturizableWindowMask
                                         backing:NSBackingStoreBuffered
                                           defer:NO];
    [window setTitle:@"hello engine"];
    [window center];
    [window makeKeyAndOrderFront:controller];
    [window setContentView:view];

    controller = [[Controller alloc] initWithWindow:window];

    auto menubar = [NSMenu new];
    auto appMenuItem = [NSMenuItem new];
    [menubar addItem:appMenuItem];
    [self setMainMenu:menubar];

    auto appMenu = [NSMenu new];
    auto appName = [[NSProcessInfo processInfo] processName];
    auto quitTitle = [@"Quit " stringByAppendingString:appName];
    auto quitMenuItem = [[NSMenuItem alloc] initWithTitle:quitTitle
        action:@selector(terminate:) keyEquivalent:@"q"];
    [appMenu addItem:quitMenuItem];
    [appMenuItem setSubmenu:appMenu];
    
    NSLog(@"app launched");
}
@end

int main(int argc, const char * argv[])
{
    AppOSX* app = [AppOSX sharedApplication];
    [app run];
    return 0;
}