//
//  NSGLWrapper.mm
//  XcodeOpenCL
//
//  Created by Joshua Moerman on 13/04/14.
//
//

#include "NSGLWrapper.hpp"

#include <iostream>
#include <stdexcept>

#import <Cocoa/Cocoa.h>
#import <OpenGL/OpenGL.h>

static void check_cgl(CGLError e) {
    if(e != kCGLNoError){
        throw std::runtime_error(CGLErrorString(e));
    }
}

GLContext::GLContext() {
    GLint npix{};
    const CGLPixelFormatAttribute attributes[]{
        kCGLPFADoubleBuffer,
        kCGLPFADepthSize,       static_cast<CGLPixelFormatAttribute>(24),
        kCGLPFAOpenGLProfile,   static_cast<CGLPixelFormatAttribute>(kCGLOGLPVersion_3_2_Core),
        static_cast<CGLPixelFormatAttribute>(0)
    };
    
    check_cgl(CGLChoosePixelFormat(attributes, &pix, &npix));
    check_cgl(CGLCreateContext(pix, 0, &ctx));
    
    GLint swap_interval = 1;
    check_cgl(CGLSetParameter(ctx, kCGLCPSwapInterval, &swap_interval));
    
    set_as_current_context();
}

GLContext::~GLContext() {
    CGLReleaseContext(ctx);
    CGLReleasePixelFormat(pix);
}

void GLContext::set_as_current_context() const {
    check_cgl(CGLSetCurrentContext(ctx));
}

void GLContext::lock() {
    check_cgl(CGLLockContext(ctx));
}

void GLContext::unlock() {
    check_cgl(CGLUnlockContext(ctx));
}



static void check_cv(CVReturn r) {
    if(r != kCVReturnSuccess){
        throw std::runtime_error("Some CV display link issue");
    }
}

static CVReturn CVDisplayLinkyInvokeCallback(CVDisplayLinkRef displayLink, const CVTimeStamp* now, const CVTimeStamp* outputTime, CVOptionFlags flagsIn, CVOptionFlags* flagsOut, void* displayLinkContext) {
    if(!displayLinkContext){
        throw std::runtime_error("There is no context in the display link");
    }
    auto& foo = *(CVDisplayLinky*)displayLinkContext;
    if(foo.callback){
        foo.callback();
    }
    return kCVReturnSuccess;
}

CVDisplayLinky::CVDisplayLinky(GLContext const & c) {
    check_cv(CVDisplayLinkCreateWithActiveCGDisplays(&displayLink));
    check_cv(CVDisplayLinkSetOutputCallback(displayLink, &CVDisplayLinkyInvokeCallback, this));
    check_cv(CVDisplayLinkSetCurrentCGDisplayFromOpenGLContext(displayLink, c.ctx, c.pix));
}

CVDisplayLinky::~CVDisplayLinky() {
    stop();
    CVDisplayLinkRelease(displayLink);
}

void CVDisplayLinky::start() {
    check_cv(CVDisplayLinkStart(displayLink));
}

void CVDisplayLinky::stop() {
    check_cv(CVDisplayLinkStop(displayLink));
}