"""GLUT functions requiring special handling to provide Pythonic wrappers

Note:
	GLUT callbacks are controlled by a flag in the platform module.  The
	GLUT_GUARD_CALLBACKS flag controls whether to wrap passed functions
	with error-checking and context-validity checking code so that the
	callbacks will only trigger if there is a valid context.  This is done
	so that systems such as Win32 will not continue running GLUT callbacks
	after the system has exited.

	Note:
		This is not a problem with FreeGLUT on Linux, so Linux does not
		add the extra overhead of the wrapper function.
	Note:
		This hack does *not* prevent hanging if there is no GLUT callback
		being triggered.  I.e. if you create a GLUT program that doesn't
		explicitly call exit and doesn't call display or the like in a timer
		then your app will hang on exit on Win32.

XXX the platform-specific stuff should be getting done in the 
platform module *not* in the module here!
"""
from OpenGL.platform import GLUT, CurrentContextIsValid, GLUT_GUARD_CALLBACKS
from OpenGL import contextdata, error, platform, logs
from OpenGL.raw import GLUT as simple
import ctypes, os, sys, traceback
PLATFORM = platform.PLATFORM
FUNCTION_TYPE = simple.CALLBACK_FUNCTION_TYPE

log = logs.getLog( 'OpenGL.GLUT.special' )

if os.name == "nt":
	log.info( """Using NT-specific GLUT calls with exit callbacks""" )
	__glutInitWithExit = platform.createBaseFunction(
		'__glutInitWithExit', dll=platform.GLUT, resultType=None,
		argTypes=[ctypes.POINTER(ctypes.c_int),ctypes.POINTER(ctypes.c_char_p),ctypes.c_void_p],
		doc='glutInit( POINTER(c_int)(pargc), POINTER(STRING)(argv) ) -> None',
		argNames=('pargc', 'argv'),
	)
	__glutCreateWindowWithExit = platform.createBaseFunction(
		'__glutCreateWindowWithExit', dll=platform.GLUT, resultType=ctypes.c_int,
		argTypes=[ctypes.c_char_p, ctypes.c_void_p],
		doc='glutCreateWindow( STRING(title) ) -> c_int',
		argNames=('title',),
	)
	__glutCreateMenuWithExit = platform.createBaseFunction( 
		'__glutCreateMenuWithExit', dll=platform.GLUT, resultType=ctypes.c_int, 
		argTypes=[FUNCTION_TYPE(None, ctypes.c_int), ctypes.c_void_p],
		doc='glutCreateMenu( FUNCTION_TYPE(None, c_int)(callback) ) -> c_int', 
		argNames=('callback',),
	)
	import sys
	_exitfunc = FUNCTION_TYPE( None, ctypes.c_int )(sys.exit)
	
	def _base_glutInit(pargc, argv):
		"""Overrides base glut init with exit-function-aware version"""
		return __glutInitWithExit(pargc, argv, _exitfunc)
	def glutCreateWindow(title):
		"""Create window with given title
		
		This is the Win32-specific version that handles
		registration of an exit-function handler 
		"""
		return __glutCreateWindowWithExit(title, _exitfunc)
	def glutCreateMenu(callback):
		"""Create menu with given callback 
		
		This is the Win32-specific version that handles 
		registration of an exit-function callback.
		"""
		return __glutCreateMenuWithExit(callback, _exitfunc)
else:
	_base_glutInit = getattr(GLUT, 'glutInit', None)
##_base_glutDisplayFunc = GLUT.glutDisplayFunc
##_base_glutIdleFunc = GLUT.glutIdleFunc
##_base_glutEntryFunc = GLUT.glutEntryFunc
##_base_glutReshapeFunc = GLUT.glutReshapeFunc
_base_glutDestroyWindow = getattr(GLUT, 'glutDestroyWindow', None)

class GLUTCallback( object ):
	"""Class implementing GLUT Callback registration functions"""
	def __init__( self, typeName, parameterTypes, parameterNames ):
		"""Initialise the glut callback instance"""
		self.typeName = typeName
		def describe( typ, name ):
			return '(int) %s'%(name)
		self.__doc__ = """Specify handler for GLUT %r events
	def handler( %s ):
		return None"""%( typeName, ", ".join([
			describe( typ,name )
			for (typ,name) in zip( parameterTypes, parameterNames )
		]))
		try:
			self.wrappedOperation = getattr( GLUT, 'glut%sFunc'%(typeName) )
		except AttributeError, err:
			def failFunction( *args, **named ):
				from OpenGL import error
				raise error.NullFunctionError(
					"""Undefined GLUT callback function %s, check for bool(%s) before calling"""%(
						typeName, 'glut%sFunc'%(typeName),
					)
				)
			self.wrappedOperation = failFunction
		self.callbackType = FUNCTION_TYPE( None, *parameterTypes )
		self.CONTEXT_DATA_KEY = 'glut%sFunc'%(typeName, )
	def __call__( self, function, *args ):
		if GLUT_GUARD_CALLBACKS and callable( function ):
			def safeCall( *args, **named ):
				"""Safe calling of GUI callbacks, exits on failures"""
				try:
					if not CurrentContextIsValid():
						raise RuntimeError( """No valid context!""" )
					return function( *args, **named )
				except Exception, err:
					traceback.print_exc()
					sys.stderr.write( """GLUT %s callback %s with %s,%s failed: returning None %s\n"""%(
						self.typeName, function, args, named, err, 
					))
					os._exit(1)
					#return None
			finalFunction = safeCall
		else:
			finalFunction = function
		if callable( finalFunction ):
			cCallback = self.callbackType( finalFunction )
		else:
			cCallback = function
		# keep the function alive as long as the cCallback is...
		#cCallback.function = function
		contextdata.setValue( self.CONTEXT_DATA_KEY, cCallback )
		self.wrappedOperation( cCallback, *args )
		return cCallback
class GLUTTimerCallback( GLUTCallback ):
	"""GLUT timer callbacks (completely nonstandard wrt other GLUT callbacks)"""
	def __call__( self, milliseconds, function, value ):
		cCallback = self.callbackType( function )
		# timers should de-register as soon as they are called...
		# Note: there's no good key to use! we want to allow for
		# multiple instances of the same function with the same value 
		# which means we have nothing that can store it properly...
		callbacks = contextdata.getValue( self.CONTEXT_DATA_KEY )
		if callbacks is None:
			callbacks = []
			contextdata.setValue( self.CONTEXT_DATA_KEY, callbacks )
		def deregister( value ):
			try:
				function( value )
			finally:
				for item in callbacks:
					if item.function is deregister:
						callbacks.remove( item )
						item.function = None
						break
				if not callbacks:
					contextdata.delValue( self.CONTEXT_DATA_KEY )
		cCallback = self.callbackType( deregister )
		cCallback.function = deregister
		callbacks.append( cCallback )
		self.wrappedOperation( milliseconds, cCallback, value )
		return cCallback

class GLUTMenuCallback( object ):
	"""Place to collect the GLUT Menu manipulation special code"""
	callbackType = FUNCTION_TYPE( ctypes.c_int, ctypes.c_int )
	def glutCreateMenu( cls, func ):
		"""Create a new (current) menu, return small integer identifier
		
		func( int ) -- Function taking a single integer reflecting
			the user's choice, the value passed to glutAddMenuEntry
		
		return menuID (small integer)
		"""
		cCallback = cls.callbackType( func )
		menu = simple.glutCreateMenu( cCallback )
		contextdata.setValue( ('menucallback',menu), (cCallback,func) )
		return menu
	glutCreateMenu.argNames = [ 'func' ]
	glutCreateMenu = classmethod( glutCreateMenu )
	def glutDestroyMenu( cls, menu ):
		"""Destroy (cleanup) the given menu
		
		Deregister's the interal pointer to the menu callback 
		
		returns None
		"""
		result = simple.glutDestroyMenu( menu )
		contextdata.delValue( ('menucallback',menu) )
		return result
	glutDestroyMenu.argNames = [ 'menu' ]
	glutDestroyMenu = classmethod( glutDestroyMenu )

glutCreateMenu = GLUTMenuCallback.glutCreateMenu
#glutCreateMenu.wrappedOperation = simple.glutCreateMenu
glutDestroyMenu = GLUTMenuCallback.glutDestroyMenu
#glutDestroyMenu.wrappedOperation = simple.glutDestroyMenu

glutButtonBoxFunc = GLUTCallback(
	'ButtonBox', (ctypes.c_int,ctypes.c_int), ('button','state'),
)
glutDialsFunc = GLUTCallback(
	'Dials', (ctypes.c_int,ctypes.c_int), ('dial','value'),
)
glutDisplayFunc = GLUTCallback(
	'Display', (), (),
)
glutEntryFunc = GLUTCallback(
	'Entry', (ctypes.c_int,), ('state',),
)
glutIdleFunc = GLUTCallback(
	'Idle', (), (),
)
glutJoystickFunc = GLUTCallback(
	'Joystick', (ctypes.c_uint,ctypes.c_int,ctypes.c_int,ctypes.c_int), ('buttonMask','x','y','z'),
)
glutKeyboardFunc = GLUTCallback(
	'Keyboard', (ctypes.c_char,ctypes.c_int,ctypes.c_int), ('key','x','y'),
)
glutKeyboardUpFunc = GLUTCallback(
	'KeyboardUp', (ctypes.c_char,ctypes.c_int,ctypes.c_int), ('key','x','y'),
)
glutMenuStatusFunc = GLUTCallback(
	'MenuStatus', (ctypes.c_int,ctypes.c_int,ctypes.c_int), ('status','x','y'),
)
glutMenuStateFunc = GLUTCallback(
	'MenuState', (ctypes.c_int,), ('status',),
)
glutMotionFunc = GLUTCallback(
	'Motion', (ctypes.c_int,ctypes.c_int), ('x','y'),
)
glutMouseFunc = GLUTCallback(
	'Mouse', (ctypes.c_int,ctypes.c_int,ctypes.c_int,ctypes.c_int), ('button','state','x','y'),
)
glutOverlayDisplayFunc = GLUTCallback(
	'OverlayDisplay', (), (),
)
glutPassiveMotionFunc = GLUTCallback(
	'PassiveMotion', (ctypes.c_int,ctypes.c_int), ('x','y'),
)
glutReshapeFunc = GLUTCallback(
	'Reshape', (ctypes.c_int,ctypes.c_int), ('width','height'),
)
glutSpaceballButtonFunc = GLUTCallback(
	'SpaceballButton', (ctypes.c_int,ctypes.c_int), ('button','state'),
)
glutSpaceballMotionFunc = GLUTCallback(
	'SpaceballMotion', (ctypes.c_int,ctypes.c_int,ctypes.c_int), ('x','y','z'),
)
glutSpaceballRotateFunc = GLUTCallback(
	'SpaceballRotate', (ctypes.c_int,ctypes.c_int,ctypes.c_int), ('x','y','z'),
)
glutSpecialFunc = GLUTCallback(
	'Special', (ctypes.c_int,ctypes.c_int,ctypes.c_int), ('key','x','y'),
)
glutSpecialUpFunc = GLUTCallback(
	'SpecialUp', (ctypes.c_int,ctypes.c_int,ctypes.c_int), ('key','x','y'),
)
glutTabletButtonFunc = GLUTCallback(
	'TabletButton', (ctypes.c_int,ctypes.c_int,ctypes.c_int,ctypes.c_int), ('button','state','x','y',),
)
glutTabletButtonFunc = GLUTCallback(
	'TabletButton', (ctypes.c_int,ctypes.c_int,ctypes.c_int,ctypes.c_int), ('button','state','x','y',),
)
glutTabletMotionFunc = GLUTCallback(
	'TabletMotion', (ctypes.c_int,ctypes.c_int), ('x','y',),
)
glutVisibilityFunc = GLUTCallback(
	'Visibility', (ctypes.c_int,), ('state',),
)
glutWindowStatusFunc = GLUTCallback(
	'WindowStatus', (ctypes.c_int,), ('state',),
)

# glutTimerFunc is unlike any other GLUT callback-registration...
glutTimerFunc = GLUTTimerCallback(
	'Timer', (ctypes.c_int,), ('value',),
)

INITIALIZED = False
def glutInit( *args ):
	"""Initialise the GLUT library"""
	global INITIALIZED
	if INITIALIZED:
		return args
	INITIALIZED = True
	if args:
		arg,args = args[0],args[1:]
		count = None
		if isinstance(arg, (int,long)):
			# raw API style, (count, values)
			count = arg
			if count != len(args):
				raise ValueError( """Specified count of %s does not match length (%s) of argument list %s"""%(
					count, len(args), args,
				))
		elif isinstance( arg, (str,unicode)):
			# passing in a sequence of strings as individual arguments
			args = (arg,)+args 
			count = len(args)
		else:
			args = arg 
			count = len(args)
	else:
		count=0
		args = []
	args = [str(x) for x in args]
	if not count:
		count, args = 1, ['foo']
	holder = (ctypes.c_char_p * len(args))()
	for i,arg in enumerate(args):
		holder[i] = arg
	count = ctypes.c_int( count )
	import os 
	currentDirectory = os.getcwd()
	try:
		# XXX need to check for error condition here...
		_base_glutInit( ctypes.byref(count), holder )
	finally:
		os.chdir( currentDirectory )
	return [
		str(holder[i]) for i in range( count.value )
	]
glutInit.wrappedOperation = simple.glutInit

def glutDestroyWindow( window ):
	"""Want to destroy the window, we need to do some cleanup..."""
	context = 0
	try:
		GLUT.glutSetWindow(window)
		context = contextdata.getContext()
		result = contextdata.cleanupContext( context )
		log.info( """Cleaning up context data for window %s: %s""", window, result )
	except Exception, err:
		log.error( """Error attempting to clean up context data for GLUT window %s: %s""", window, result )
	return _base_glutDestroyWindow( window )
glutDestroyWindow.wrappedOperation = simple.glutDestroyWindow

