// -*- objc -*-

#include "ebiten_opengl_view.h"

// Reference:
//   http://developer.apple.com/library/mac/#qa/qa1385/_index.html
//   http://www.alecjacobson.com/weblog/?p=2185

// TODO: Use NSViewController?

static CVReturn
EbitenDisplayLinkCallback(CVDisplayLinkRef displayLink,
                          CVTimeStamp const* now,
                          CVTimeStamp const* outputTime,
                          CVOptionFlags flagsIn,
                          CVOptionFlags* flagsOut,
                          void* displayLinkContext) {
  (void)displayLink;
  (void)now;
  (void)flagsIn;
  (void)flagsOut;
  @autoreleasepool {
    EbitenOpenGLView* view = (__bridge EbitenOpenGLView*)displayLinkContext;
    return [view getFrameForTime:outputTime];
  }
}

@implementation EbitenOpenGLView {
@private
  CVDisplayLinkRef displayLink_;
  updating* updating_;
  //ebiten::input* input_;
}

- (id)init {
  if (self = [super init]) {
    self->updating_ = NULL;
  }
  return self;
}

- (void)dealloc {
  CVDisplayLinkRelease(self->displayLink_);
  // Do not call [super dealloc] because of ARC.
}

- (void)prepareOpenGL {
  [super prepareOpenGL];
  NSOpenGLContext* openGLContext = [self openGLContext];
  assert(openGLContext != nil);
  GLint const swapInterval = 1;
  [openGLContext setValues:&swapInterval
              forParameter:NSOpenGLCPSwapInterval]; 
  CVDisplayLinkCreateWithActiveCGDisplays(&self->displayLink_);
  CVDisplayLinkSetOutputCallback(self->displayLink_,
                                   &EbitenDisplayLinkCallback,
                                   (__bridge void*)self);
  CGLContextObj cglContext = (CGLContextObj)[openGLContext CGLContextObj];
  CGLPixelFormatObj cglPixelFormat =
    (CGLPixelFormatObj)[[self pixelFormat] CGLPixelFormatObj];
  CVDisplayLinkSetCurrentCGDisplayFromOpenGLContext(self->displayLink_,
                                                      cglContext,
                                                      cglPixelFormat);
  CVDisplayLinkStart(self->displayLink_);
}

- (CVReturn)getFrameForTime:(CVTimeStamp const*)outputTime {
  (void)outputTime;
  if (!self->updating_) {
    return kCVReturnSuccess;
  }
  NSOpenGLContext* context = [self openGLContext];
  assert(context != nil);
  [context makeCurrentContext];
  bool terminated = false;
  {
    CGLLockContext((CGLContextObj)[context CGLContextObj]);
    terminated = self->updating_();
    [context flushBuffer];
    CGLUnlockContext((CGLContextObj)[context CGLContextObj]);
  }
  if (terminated) {
    //CVDisplayLinkStop(self->displayLink_);
    [NSApp terminate:nil];
    return kCVReturnSuccess;
  }
  return kCVReturnSuccess;
}

- (void)setUpdatingFunc:(updating*)func {
  self->updating_ = func;
}

// TODO
// - (void)setInput:(ebiten::input&)input {
//   self->input_ = &input;
// }

- (BOOL)isFlipped {
  return YES;
}

- (void)mouseDown:(NSEvent*)theEvent {
  NSPoint location = [self convertPoint:[theEvent locationInWindow]
                               fromView:nil];
  // TODO
  /*
  if (self->input_) {
    int x = location.x;
    int y = location.y;
    // TODO: Screen size
    self->input_->set_touches_real_location(0,
                                            static_cast<int>(x),
                                            static_cast<int>(y));
    self->input_->set_touched(0, true);
    }*/
}

- (void)mouseUp:(NSEvent*)theEvent {
  (void)theEvent;
  // TODO
  /*if (self->input_) {
    self->input_->set_touches_real_location(0, -1, -1);
    self->input_->set_touched(0, false);
    }*/
}

- (void)mouseDragged:(NSEvent*)theEvent {
  NSPoint location = [self convertPoint:[theEvent locationInWindow]
                               fromView:nil];
  // TODO
  /*if (self->input_) {
    int x = location.x;
    int y = location.y;
    self->input_->set_touches_real_location(0,
                                            static_cast<int>(x),
                                            static_cast<int>(y));
    self->input_->set_touched(0, true);
    }*/
}

@end