/*
  Copyright 2012-2014 David Robillard <http://drobilla.net>

  Permission to use, copy, modify, and/or distribute this software for any
  purpose with or without fee is hereby granted, provided that the above
  copyright notice and this permission notice appear in all copies.

  THIS SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
  WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/

/**
   @file pugl_osx.m OSX/Cocoa Pugl Implementation.
*/

#include <stdlib.h>

#import <Cocoa/Cocoa.h>

#ifdef PUGL_HAVE_GL
#include "pugl/gl.h"
#endif

#include "pugl/pugl_internal.h"

@interface PuglWindow : NSWindow
{
@public
	PuglView* puglview;
}

- (id) initWithContentRect:(NSRect)contentRect
                 styleMask:(unsigned int)aStyle
                   backing:(NSBackingStoreType)bufferingType
                     defer:(BOOL)flag;
- (void) setPuglview:(PuglView*)view;
- (BOOL) windowShouldClose:(id)sender;
- (BOOL) canBecomeKeyWindow:(id)sender;
@end

@implementation PuglWindow

- (id)initWithContentRect:(NSRect)contentRect
                styleMask:(unsigned int)aStyle
                  backing:(NSBackingStoreType)bufferingType
                    defer:(BOOL)flag
{
	if (![super initWithContentRect:contentRect
	                      styleMask:(NSClosableWindowMask |
	                                 NSTitledWindowMask |
	                                 NSResizableWindowMask)
	                        backing:NSBackingStoreBuffered defer:NO]) {
		return nil;
	}

	[self setAcceptsMouseMovedEvents:YES];
	[self setLevel: CGShieldingWindowLevel() + 1];
	return self;
}

- (void)setPuglview:(PuglView*)view
{
	puglview = view;
	[self setContentSize:NSMakeSize(view->width, view->height)];
}

- (BOOL)windowShouldClose:(id)sender
{
	if (puglview->closeFunc)
		puglview->closeFunc(puglview);
	return YES;
}

- (BOOL) canBecomeKeyWindow
{
	return YES;
}

- (BOOL) canBecomeMainWindow
{
	return YES;
}

- (BOOL) canBecomeKeyWindow:(id)sender
{
	return NO;
}

@end

static void
puglDisplay(PuglView* view)
{
	if (view->displayFunc) {
		view->displayFunc(view);
	}
}

@interface PuglOpenGLView : NSOpenGLView
{
	int colorBits;
	int depthBits;
@public
	PuglView* puglview;

	NSTrackingArea* trackingArea;
}

- (id) initWithFrame:(NSRect)frame
           colorBits:(int)numColorBits
           depthBits:(int)numDepthBits;
- (void) reshape;
- (void) drawRect:(NSRect)rect;
- (void) mouseEntered:(NSEvent*)event;
- (void) mouseExited:(NSEvent*)event;
- (void) mouseMoved:(NSEvent*)event;
- (void) mouseDragged:(NSEvent*)event;
- (void) rightMouseDragged:(NSEvent*)event;
- (void) mouseDown:(NSEvent*)event;
- (void) mouseUp:(NSEvent*)event;
- (void) rightMouseDragged:(NSEvent*)event;
- (void) rightMouseDown:(NSEvent*)event;
- (void) rightMouseUp:(NSEvent*)event;
- (void) scrollWheel:(NSEvent*)event;
- (void) keyDown:(NSEvent*)event;
- (void) keyUp:(NSEvent*)event;
- (void) flagsChanged:(NSEvent*)event;

@end

@implementation PuglOpenGLView

- (id) initWithFrame:(NSRect)frame
           colorBits:(int)numColorBits
           depthBits:(int)numDepthBits
{
	colorBits = numColorBits;
	depthBits = numDepthBits;

	NSOpenGLPixelFormatAttribute pixelAttribs[16] = {
		NSOpenGLPFADoubleBuffer,
		NSOpenGLPFAAccelerated,
		NSOpenGLPFAColorSize,
		colorBits,
		NSOpenGLPFADepthSize,
		depthBits,
		0
	};

	NSOpenGLPixelFormat* pixelFormat = [
		[NSOpenGLPixelFormat alloc] initWithAttributes:pixelAttribs];

	if (pixelFormat) {
		self = [super initWithFrame:frame pixelFormat:pixelFormat];
		[pixelFormat release];
		if (self) {
			[[self openGLContext] makeCurrentContext];
			[self reshape];
		}
	} else {
		self = nil;
	}

	return self;
}

- (void) reshape
{
	[[self openGLContext] update];

	if (!puglview) {
		return;
	}

	const NSRect             bounds = [self bounds];
	const PuglEventConfigure ev     =  {
		PUGL_CONFIGURE,
		puglview,
		false,
		bounds.origin.x,
		bounds.origin.y,
		bounds.size.width,
		bounds.size.height,
	};
	puglDispatchEvent(puglview, (PuglEvent*)&ev);
}

- (void) drawRect:(NSRect)rect
{
	puglDisplay(puglview);
	glFlush();
	[[self openGLContext] flushBuffer];
}

- (BOOL) acceptsFirstResponder
{
	return YES;
}

static unsigned
getModifiers(PuglView* view, NSEvent* ev)
{
	const unsigned modifierFlags = [ev modifierFlags];

	view->event_timestamp_ms = fmod([ev timestamp] * 1000.0, UINT32_MAX);

	unsigned mods = 0;
	mods |= (modifierFlags & NSShiftKeyMask)     ? PUGL_MOD_SHIFT : 0;
	mods |= (modifierFlags & NSControlKeyMask)   ? PUGL_MOD_CTRL  : 0;
	mods |= (modifierFlags & NSAlternateKeyMask) ? PUGL_MOD_ALT   : 0;
	mods |= (modifierFlags & NSCommandKeyMask)   ? PUGL_MOD_SUPER : 0;
	return mods;
}

-(void)updateTrackingAreas
{
	if (trackingArea != nil) {
		[self removeTrackingArea:trackingArea];
		[trackingArea release];
	}

	const int opts = (NSTrackingMouseEnteredAndExited |
	                  NSTrackingMouseMoved |
	                  NSTrackingActiveAlways);
	trackingArea = [ [NSTrackingArea alloc] initWithRect:[self bounds]
	                                             options:opts
	                                               owner:self
	                                            userInfo:nil];
	[self addTrackingArea:trackingArea];
}

- (void)mouseEntered:(NSEvent*)theEvent
{
	[self updateTrackingAreas];
}

- (void)mouseExited:(NSEvent*)theEvent
{
}

- (void) mouseMoved:(NSEvent*)event
{
	const NSPoint         wloc = [event locationInWindow];
	const NSPoint         rloc = [NSEvent mouseLocation];
	const PuglEventMotion ev   =  {
		PUGL_MOTION_NOTIFY,
		puglview,
		false,
		[event timestamp],
		wloc.x,
		puglview->height - wloc.y,
		rloc.x,
		[[NSScreen mainScreen] frame].size.height - rloc.y,
		getModifiers(puglview, event),
		0,
		1
	};
	puglDispatchEvent(puglview, (PuglEvent*)&ev);
}

- (void) mouseDragged:(NSEvent*)event
{
	[self mouseMoved: event];
}

- (void) rightMouseDragged:(NSEvent*)event
{
	[self mouseMoved: event];
}

- (void) mouseDown:(NSEvent*)event
{
	const NSPoint         wloc = [event locationInWindow];
	const NSPoint         rloc = [NSEvent mouseLocation];
	const PuglEventButton ev   =  {
		PUGL_BUTTON_PRESS,
		puglview,
		false,
		[event timestamp],
		wloc.x,
		puglview->height - wloc.y,
		rloc.x,
		[[NSScreen mainScreen] frame].size.height - rloc.y,
		getModifiers(puglview, event),
		[event buttonNumber]
	};
	puglDispatchEvent(puglview, (PuglEvent*)&ev);
}

- (void) mouseUp:(NSEvent*)event
{
	const NSPoint         wloc = [event locationInWindow];
	const NSPoint         rloc = [NSEvent mouseLocation];
	const PuglEventButton ev   =  {
		PUGL_BUTTON_RELEASE,
		puglview,
		false,
		[event timestamp],
		wloc.x,
		puglview->height - wloc.y,
		rloc.x,
		[[NSScreen mainScreen] frame].size.height - rloc.y,
		getModifiers(puglview, event),
		[event buttonNumber]
	};
	puglDispatchEvent(puglview, (PuglEvent*)&ev);
	[self updateTrackingAreas];
}

- (void) rightMouseDown:(NSEvent*)event
{
	[self mouseDown: event];
}

- (void) rightMouseUp:(NSEvent*)event
{
	[self mouseUp: event];
}

- (void) scrollWheel:(NSEvent*)event
{
	[self updateTrackingAreas];

	const NSPoint         wloc = [event locationInWindow];
	const NSPoint         rloc = [NSEvent mouseLocation];
	const PuglEventScroll ev   =  {
		PUGL_SCROLL,
		puglview,
		false,
		[event timestamp],
		wloc.x,
		puglview->height - wloc.y,
		rloc.x,
		[[NSScreen mainScreen] frame].size.height - rloc.y,
		getModifiers(puglview, event),
		[event deltaX],
		[event deltaY]
	};
	puglDispatchEvent(puglview, (PuglEvent*)&ev);
	[self updateTrackingAreas];
}

- (void) keyDown:(NSEvent*)event
{
	if (puglview->ignoreKeyRepeat && [event isARepeat]) {
		return;
	}

	const NSPoint      wloc  = [event locationInWindow];
	const NSPoint      rloc  = [NSEvent mouseLocation];
	const NSString*    chars = [event characters];
	const PuglEventKey ev    =  {
		PUGL_KEY_PRESS,
		puglview,
		false,
		[event timestamp],
		wloc.x,
		puglview->height - wloc.y,
		rloc.x,
		[[NSScreen mainScreen] frame].size.height - rloc.y,
		getModifiers(puglview, event),
		[chars characterAtIndex:0],
		0  // TODO: Special keys?
	};
	puglDispatchEvent(puglview, (PuglEvent*)&ev);
}

- (void) keyUp:(NSEvent*)event
{
	const NSPoint      wloc  = [event locationInWindow];
	const NSPoint      rloc  = [NSEvent mouseLocation];
	const NSString*    chars = [event characters];
	const PuglEventKey ev    =  {
		PUGL_KEY_RELEASE,
		puglview,
		false,
		[event timestamp],
		wloc.x,
		puglview->height - wloc.y,
		rloc.x,
		[[NSScreen mainScreen] frame].size.height - rloc.y,
		getModifiers(puglview, event),
		[chars characterAtIndex:0],
		0  // TODO: Special keys?
	};
	puglDispatchEvent(puglview, (PuglEvent*)&ev);
}

- (void) flagsChanged:(NSEvent*)event
{
	if (puglview->specialFunc) {
		const unsigned mods = getModifiers(puglview, event);
		if ((mods & PUGL_MOD_SHIFT) != (puglview->mods & PUGL_MOD_SHIFT)) {
			puglview->specialFunc(puglview, mods & PUGL_MOD_SHIFT, PUGL_KEY_SHIFT);
		} else if ((mods & PUGL_MOD_CTRL) != (puglview->mods & PUGL_MOD_CTRL)) {
			puglview->specialFunc(puglview, mods & PUGL_MOD_CTRL, PUGL_KEY_CTRL);
		} else if ((mods & PUGL_MOD_ALT) != (puglview->mods & PUGL_MOD_ALT)) {
			puglview->specialFunc(puglview, mods & PUGL_MOD_ALT, PUGL_KEY_ALT);
		} else if ((mods & PUGL_MOD_SUPER) != (puglview->mods & PUGL_MOD_SUPER)) {
			puglview->specialFunc(puglview, mods & PUGL_MOD_SUPER, PUGL_KEY_SUPER);
		}
		puglview->mods = mods;
	}
}

@end

struct PuglInternalsImpl {
	NSApplication*  app;
	PuglOpenGLView* glview;
	id              window;
};

PuglInternals*
puglInitInternals()
{
	return (PuglInternals*)calloc(1, sizeof(PuglInternals));
}

void
puglEnterContext(PuglView* view)
{
#ifdef PUGL_HAVE_GL
	if (view->ctx_type == PUGL_GL) {
		[[view->impl->glview openGLContext] makeCurrentContext];
	}
#endif
}

void
puglLeaveContext(PuglView* view, bool flush)
{
#ifdef PUGL_HAVE_GL
	if (view->ctx_type == PUGL_GL && flush) {
		[[view->impl->glview openGLContext] flushBuffer];
	}
#endif
}

int
puglCreateWindow(PuglView* view, const char* title)
{
	PuglInternals* impl = view->impl;

	[NSAutoreleasePool new];
	impl->app = [NSApplication sharedApplication];

	NSString* titleString = [[NSString alloc]
		                        initWithBytes:title
		                               length:strlen(title)
		                             encoding:NSUTF8StringEncoding];

	id window = [[PuglWindow new]retain];

	[window setPuglview:view];
	[window setTitle:titleString];

	impl->glview           = [PuglOpenGLView new];
	impl->window           = window;
	impl->glview->puglview = view;

	[window setContentView:impl->glview];
	[impl->app activateIgnoringOtherApps:YES];
	[window makeFirstResponder:impl->glview];
	[window makeKeyAndOrderFront:window];

	return 0;
}

void
puglShowWindow(PuglView* view)
{
	[view->impl->window setIsVisible:YES];
}

void
puglHideWindow(PuglView* view)
{
	[view->impl->window setIsVisible:NO];
}

void
puglDestroy(PuglView* view)
{
	view->impl->glview->puglview = NULL;
	[view->impl->window close];
	[view->impl->glview release];
	[view->impl->window release];
	free(view->impl);
	free(view);
}

void
puglGrabFocus(PuglView* view)
{
	// TODO
}

PuglStatus
puglProcessEvents(PuglView* view)
{
	NSEvent* ev = [view->impl->window nextEventMatchingMask: NSAnyEventMask];
	[view->impl->app sendEvent: ev];
	[view->impl->glview setNeedsDisplay: YES];

	return PUGL_SUCCESS;
}

void
puglPostRedisplay(PuglView* view)
{
	view->redisplay = true;
}

PuglNativeWindow
puglGetNativeWindow(PuglView* view)
{
	return (PuglNativeWindow)view->impl->glview;
}