"""The wrapping code for providing natural ctypes-based OpenGL interface"""
import ctypes, logging
from OpenGL import platform, error
from OpenGL._configflags import STORE_POINTERS, ERROR_ON_COPY, SIZE_1_ARRAY_UNPACK
glGetError = platform.OpenGL.glGetError
from OpenGL import converters
from OpenGL.converters import DefaultCConverter
from OpenGL.converters import returnCArgument,returnPyArgument
from OpenGL.latebind import LateBind
log = logging.getLogger( 'OpenGL.wrapper' )

from OpenGL import acceleratesupport
cWrapper = None
if acceleratesupport.ACCELERATE_AVAILABLE:
    try:
        from OpenGL_accelerate.latebind import LateBind
        from OpenGL_accelerate.wrapper import (
            Wrapper as cWrapper,
            CArgCalculator,
            PyArgCalculator,
            CArgumentCalculator,
        )
    except ImportError, err:
        log.warn( """OpenGL_accelerate seems to be installed, but unable to import expected wrapper entry points!""" )
NULL = object()

if not STORE_POINTERS:
    if not ERROR_ON_COPY:
        log.error( """You've specified (not STORE_POINTERS) yet ERROR_ON_COPY is False, this would cause segfaults, so (not STORE_POINTERS) is being ignored""" )
        STORE_POINTERS = True


def asList( o ):
    """Convert to a list if not already one"""
    if not isinstance( o, list ):
        return list(o)
    return o

class Wrapper( LateBind ):
    """Wrapper around a ctypes cFunction object providing SWIG-like hooks

    Attributes:

        wrappedOperation -- base operation, normally a ctypes function
            with data-types and error-checking specified
        pyConverters -- converters for incoming Python arguments,
            provide 1:1 mapping to incoming Python arguments, can
            suppress an argument from the argument-set as well
                see setPyConverter
        pyConverterNames -- caching/storage of the argument names
            for the Python converters
        cConverters -- converters for incoming C-level arguments
            produce Python-level objects in 1:1 mapping to ctypes
            arguments from pyConverters results
                see setCConverter
        cResolvers -- converters turning Python-level objects into
            ctypes-compatible data-types
                see setCResolver

    Generic Attributes:

        {ARG1}_LOOKUP_{ARG2} -- lookup dictionaries to provide sizes for
            ARG1 output value from the value of ARG2, provided for
            documentation/reference
        {ARG1}_FROM_{ARG2} -- lookup functions to provide sizes for ARG1
            output value from the value of ARG2, provided for
            documentation/reference
    """
    localProperties = (
        'wrappedOperation',
        '__file__',
        'pyConverters',
        'pyConverterNames',
        'cConverters',
        'cResolvers',
        'storeValues',
        'returnValues',
        '_finalCall',
    )
    def __init__( self, wrappedOperation ):
        """Initialise the wrapper, storing wrappedOperation"""
        if isinstance( wrappedOperation, Wrapper ):
            wrappedOperation = wrappedOperation.wrappedOperation
        self.wrappedOperation = wrappedOperation
    def __getattr__( self, key ):
        """Delegate attribute lookup to our wrappedOperation"""
        if key != 'wrappedOperation':
            return getattr( self.wrappedOperation, key )
        raise AttributeError( key )
    def __nonzero__( self ):
        """Is this function/wrapper available?"""
        return bool( self.wrappedOperation )
    def __setattr__( self, key, value ):
        """Forward attribute setting to our wrappedOperation"""
        if key in self.localProperties:
            super( Wrapper, self ).__setattr__( key, value )
        else:
            return setattr( self.wrappedOperation, key, value )
    def pyArgIndex( self, argName ):
        """Return the Python-argument index for the given argument name"""
        argNames = getattr( self, 'pyConverterNames', None )
        if argNames is None:
            argNames = self.wrappedOperation.argNames
        try:
            return asList( argNames ).index( argName )
        except (ValueError,IndexError), err:
            raise KeyError( """No argument %r in argument list %r"""%(
                argName, argNames
            ))
    def cArgIndex( self, argName ):
        """Return the C-argument index for the given argument name"""
        argNames = self.wrappedOperation.argNames
        try:
            return asList( argNames ).index( argName )
        except (ValueError,IndexError), err:
            raise KeyError( """No argument %r in argument list %r"""%(
                argName, argNames
            ))
    def setOutput(
        self, outArg, size=(1,), pnameArg=None,
        arrayType=None, oldStyleReturn=SIZE_1_ARRAY_UNPACK,
        orPassIn = False,
    ):
        """Set the given argName to be an output array

        size -- either a tuple compatible with arrayType.zeros or
            a function taking pname to produce such a value.
        arrayType -- array data-type used to generate the output
            array using the zeros class method...
        pname -- optional argument passed into size function, that
            is, the name of the argument whose *value* will be passed
            to the size function, often the name of an input argument
            to be "sized" to match the output argument.
        """
        if arrayType is None:
            # figure out from self.wrappedOperation's argtypes
            index = self.cArgIndex( outArg )
            arrayType = self.wrappedOperation.argtypes[ index ]
        if pnameArg is None:
            assert not hasattr(size,'__call__' )
            conv = converters.Output(
                name=outArg,
                size=size,
                arrayType=arrayType,
            )
        else:
            if isinstance( size, dict ):
                setattr( self, '%s_LOOKUP_%s'%(outArg,pnameArg), size )
                size = size.__getitem__
            else:
                setattr( self, '%s_FROM_%s'%(outArg,pnameArg), size )
            assert hasattr( size, '__call__' )
            conv = converters.SizedOutput(
                name=outArg,
                specifier=pnameArg,
                lookup=size,
                arrayType=arrayType,
            )
        if oldStyleReturn:
            returnObject = conv.oldStyleReturn
        else:
            returnObject = converters.returnCArgument( outArg )
        if orPassIn:
            self.setPyConverter(
                outArg, None
            )
        else:
            self.setPyConverter( outArg )
        return self.setCConverter(
            outArg, conv,
        ).setReturnValues(
            returnObject
        )
    def setPyConverter( self, argName, function = NULL ):
        """Set Python-argument converter for given argument

        argName -- the argument name which will be coerced to a usable internal
            format using the function provided.
        function -- None (indicating a simple copy), NULL (default) to eliminate
            the argument from the Python argument-list, or a callable object with
            the signature:

                converter(arg, wrappedOperation, args)

            where arg is the particular argument on which the convert is working,
            wrappedOperation is the underlying wrapper, and args is the set of
            original Python arguments to the function.

        Note that you need exactly the same number of pyConverters as Python
        arguments.
        """
        if not hasattr( self, 'pyConverters' ):
            self.pyConverters = [None]*len( self.wrappedOperation.argNames )
            self.pyConverterNames = list(self.wrappedOperation.argNames)
        try:
            i = asList( self.pyConverterNames ).index( argName )
        except ValueError:
            raise AttributeError( """No argument named %r left in pyConverters for %r: %s"""%(
                argName, self.wrappedOperation.__name__, self.pyConverterNames,
            ))
        if function is NULL:
            del self.pyConverters[i]
            del self.pyConverterNames[i]
        else:
            self.pyConverters[i] = function
        return self
    def setCConverter( self, argName, function ):
        """Set C-argument converter for a given argument

        argName -- the argument name whose C-compatible representation will
            be calculated with the passed function.
        function -- None (indicating a simple copy), a non-callable object to
            be copied into the result-list itself, or a callable object with
            the signature:

                converter( pyArgs, index, wrappedOperation )

            where pyArgs is the set of passed Python arguments, with the
            pyConverters already applied, index is the index of the C argument
            and wrappedOperation is the underlying function.

        C-argument converters are your chance to expand/contract a Python
        argument list (pyArgs) to match the number of arguments expected by
        the ctypes baseOperation.  You can't have a "null" C-argument converter,
        as *something* has to be passed to the C-level function in the
        parameter.
        """
        if not hasattr( self, 'cConverters' ):
            self.cConverters = [None]*len( self.wrappedOperation.argNames )
        try:
            if not isinstance(self.wrappedOperation.argNames, list):
                self.wrappedOperation.argNames = list( self.wrappedOperation.argNames )
            i = asList( self.wrappedOperation.argNames ).index( argName )
        except ValueError:
            raise AttributeError( """No argument named %r left in cConverters: %s"""%(
                argName, self.wrappedOperation.argNames,
            ))
        self.cConverters[i] = function
        return self
    def setCResolver( self, argName, function=NULL ):
        """Set C-argument converter for a given argument"""
        if not hasattr( self, 'cResolvers' ):
            self.cResolvers = [None]*len( self.wrappedOperation.argNames )
        try:
            if not isinstance(self.wrappedOperation.argNames, list):
                self.wrappedOperation.argNames = list( self.wrappedOperation.argNames )
            i = asList( self.wrappedOperation.argNames).index( argName )
        except ValueError:
            raise AttributeError( """No argument named %r left in cConverters: %s"""%(
                argName, self.wrappedOperation.argNames,
            ))
        if function is NULL:
            del self.cResolvers[i]
        else:
            self.cResolvers[i] = function
        return self
    def setStoreValues( self, function=NULL ):
        """Set the storage-of-arguments function for the whole wrapper"""
        if function is NULL or ERROR_ON_COPY and not STORE_POINTERS:
            try:
                del self.storeValues
            except Exception, err:
                pass
        else:
            self.storeValues = function
        return self
    def setReturnValues( self, function=NULL ):
        """Set the return-of-results function for the whole wrapper"""
        if function is NULL:
            try:
                del self.returnValues
            except Exception, err:
                pass
        else:
            self.returnValues = function
        return self
    def finalise( self ):
        """Finalise our various elements into simple index-based operations"""
        for attribute in ('pyConverters','cConverters','cResolvers' ):
            value = getattr( self, attribute, None )
            if value is not None:
                for i,item in enumerate(value):
                    if hasattr( item, 'finalise' ):
                        try:
                            item.finalise( self )
                        except Exception, err:
                            raise error.Error(
                                """Error finalising item %s in %s for %s (%r): %s"""%(
                                    i,attribute,self,item,err,
                                )
                            )
        if hasattr( self, 'cConverters' ):
            for i,converter in enumerate( self.cConverters ):
                if isinstance( converter, (type(None),DefaultCConverter )):
                    self.cConverters[i] = DefaultCConverter( self.pyArgIndex( self.argNames[i]) )
        for attribute in ('storeValues','returnValues',):
            item = getattr( self, attribute, None )
            if hasattr( item, 'finalise' ):
                item.finalise( self )
        callFunction = self.finaliseCall()
        if not callFunction:
            raise RuntimeError( """Missing finalised call type for %s"""%( self, ))
        else:
            #self.__class__.finalize = lambda *args: callFunction
            #self.__call__ = callFunction
            #self.__class__.__call__ = callFunction
            #self.__class__.set_call( callFunction )
            #self.__class__.__dict__[ '__call__' ] = callFunction
            #print 'setting class call', callFunction
            self.setFinalCall( callFunction )
            return callFunction
        #return self
    def finaliseCall( self ):
        """Produce specialised versions of call for finalised wrapper object

        This returns a version of __call__ that only does that work which is
        required by the particular wrapper object

        This is essentially a huge set of expanded nested functions, very
        inelegant...
        """
        pyConverters = getattr( self, 'pyConverters', None )
        cConverters = getattr( self, 'cConverters', None )
        cResolvers = getattr( self, 'cResolvers', None )
        wrappedOperation = self.wrappedOperation
        storeValues = getattr( self, 'storeValues', None )
        returnValues = getattr( self, 'returnValues', None )
        if pyConverters:
            if cWrapper:
                calculate_pyArgs = PyArgCalculator(
                    self,pyConverters,
                )
            else:
                pyConverters_mapped = [
                    (i,converter,(converter is None))
                    for (i,converter) in enumerate( pyConverters )
                ]
                pyConverters_length = len(pyConverters)
                def calculate_pyArgs( args ):
                    if pyConverters_length != len(args):
                        raise ValueError(
                            """%s requires %r arguments (%s), received %s: %r"""%(
                                wrappedOperation.__name__,
                                pyConverters_length,
                                ", ".join( self.pyConverterNames ),
                                len(args),
                                args
                            )
                        )
                    for index,converter,isNone in pyConverters_mapped:
                        if isNone:
                            yield args[index]
                        else:
                            try:
                                yield converter(args[index], self, args)
                            except Exception, err:
                                if hasattr( err, 'args' ):
                                    err.args += ( converter, )
                                raise
        else:
            calculate_pyArgs = None
        if cConverters:
            if cWrapper:
                calculate_cArgs = CArgCalculator( self, cConverters )
            else:
                cConverters_mapped = [
                    (i,converter,hasattr(converter,'__call__'))
                    for (i,converter) in enumerate( cConverters )
                ]
                def calculate_cArgs( pyArgs ):
                    for index,converter,canCall in cConverters_mapped:
                        if canCall:
                            try:
                                yield converter( pyArgs, index, self )
                            except Exception, err:
                                if hasattr( err, 'args' ):
                                    err.args += (
                                        """Failure in cConverter %r"""%(converter),
                                        pyArgs, index, self,
                                    )
                                raise
                        else:
                            yield converter
        else:
            calculate_cArgs = None
        if cResolvers:
            if cWrapper:
                calculate_cArguments = CArgumentCalculator( cResolvers )
            else:
                cResolvers_mapped = list(enumerate(cResolvers))
                def calculate_cArguments( cArgs ):
                    for i,converter in cResolvers_mapped:
                        if converter is None:
                            yield cArgs[i]
                        else:
                            try:
                                yield converter( cArgs[i] )
                            except Exception, err:
                                err.args += (converter,)
                                raise
        else:
            calculate_cArguments = None
        if cWrapper:
            return cWrapper(
                wrappedOperation,
                calculate_pyArgs=calculate_pyArgs,
                calculate_cArgs=calculate_cArgs,
                calculate_cArguments=calculate_cArguments,
                storeValues=storeValues,
                returnValues=returnValues,
            )
        if pyConverters:
            if cConverters:
                # create a map of index,converter, callable
                if cResolvers:
                    if storeValues:
                        if returnValues:
                            def wrapperCall( *args ):
                                """Wrapper with all possible operations"""
                                pyArgs = tuple( calculate_pyArgs( args ))
                                cArgs = tuple(calculate_cArgs( pyArgs ))
                                cArguments = tuple(calculate_cArguments( cArgs ))
                                try:
                                    result = self.wrappedOperation( *cArguments )
                                except ctypes.ArgumentError, err:
                                    err.args = err.args + (cArguments,)
                                    raise err
                                except error.GLError, err:
                                    err.cArgs = cArgs
                                    err.pyArgs = pyArgs
                                    raise err
                                # handle storage of persistent argument values...
                                storeValues(
                                    result,
                                    self,
                                    pyArgs,
                                    cArgs,
                                )
                                return returnValues(
                                    result,
                                    self,
                                    pyArgs,
                                    cArgs,
                                )
                            return wrapperCall
                        else:
                            def wrapperCall( *args ):
                                """Wrapper with all save returnValues"""
                                pyArgs = tuple( calculate_pyArgs( args ))
                                cArgs = tuple(calculate_cArgs( pyArgs ))
                                cArguments = tuple(calculate_cArguments( cArgs ))
                                try:
                                    result = self.wrappedOperation( *cArguments )
                                except ctypes.ArgumentError, err:
                                    err.args = err.args + (cArguments,)
                                    raise err
                                except error.GLError, err:
                                    err.cArgs = cArgs
                                    err.pyArgs = pyArgs
                                    raise err
                                # handle storage of persistent argument values...
                                storeValues(
                                    result,
                                    self,
                                    pyArgs,
                                    cArgs,
                                )
                                return result
                            return wrapperCall
                    else: # null storeValues
                        if returnValues:
                            def wrapperCall( *args ):
                                """Wrapper with all save storeValues"""
                                pyArgs = tuple( calculate_pyArgs( args ))
                                cArgs = tuple(calculate_cArgs( pyArgs ))
                                cArguments = tuple(calculate_cArguments( cArgs ))
                                try:
                                    result = self.wrappedOperation( *cArguments )
                                except ctypes.ArgumentError, err:
                                    err.args = err.args + (cArguments,)
                                    raise err
                                except error.GLError, err:
                                    err.cArgs = cArgs
                                    err.pyArgs = pyArgs
                                    raise err
                                return returnValues(
                                    result,
                                    self,
                                    pyArgs,
                                    cArgs,
                                )
                            return wrapperCall
                        else:
                            def wrapperCall( *args ):
                                """Wrapper with all save returnValues and storeValues"""
                                pyArgs = tuple( calculate_pyArgs( args ))
                                cArgs = tuple(calculate_cArgs( pyArgs ))
                                cArguments = tuple(calculate_cArguments( cArgs ))
                                try:
                                    result = self.wrappedOperation( *cArguments )
                                except ctypes.ArgumentError, err:
                                    err.args = err.args + (cArguments,)
                                    raise err
                                except error.GLError, err:
                                    err.cArgs = cArgs
                                    err.pyArgs = pyArgs
                                    raise err
                                return result
                            return wrapperCall
                else:
                    # null cResolvers
                    if storeValues:
                        if returnValues:
                            def wrapperCall( *args ):
                                """Wrapper with all possible operations"""
                                pyArgs = tuple( calculate_pyArgs( args ))
                                cArgs = tuple(calculate_cArgs( pyArgs ))
                                cArguments = cArgs
                                try:
                                    result = self.wrappedOperation( *cArguments )
                                except ctypes.ArgumentError, err:
                                    err.args = err.args + (cArguments,)
                                    raise err
                                except error.GLError, err:
                                    err.cArgs = cArgs
                                    err.pyArgs = pyArgs
                                    raise err
                                # handle storage of persistent argument values...
                                storeValues(
                                    result,
                                    self,