import pypy.module.cppyy.capi as capi

from pypy.interpreter.error import OperationError
from pypy.interpreter.gateway import interp2app, unwrap_spec
from pypy.interpreter.typedef import TypeDef, GetSetProperty, interp_attrproperty
from pypy.interpreter.baseobjspace import W_Root

from rpython.rtyper.lltypesystem import rffi, lltype, llmemory

from rpython.rlib import jit, rdynload, rweakref
from rpython.rlib import jit_libffi, clibffi

from pypy.module.cppyy import converter, executor, helper


class FastCallNotPossible(Exception):
    pass

# overload priorities: lower is preferred
priority = { 'void*'  : 100,
             'void**' : 100,
             'float'  :  30,
             'double' :  10, }

from rpython.rlib.listsort import make_timsort_class
CPPMethodBaseTimSort = make_timsort_class()
class CPPMethodSort(CPPMethodBaseTimSort):
    def lt(self, a, b):
        return a.priority() < b.priority()

@unwrap_spec(name=str)
def load_dictionary(space, name):
    try:
        cdll = capi.c_load_dictionary(name)
    except rdynload.DLOpenError, e:
        raise OperationError(space.w_RuntimeError, space.wrap(str(e.msg)))
    return W_CPPLibrary(space, cdll)

class State(object):
    def __init__(self, space):
        self.cppscope_cache = {
            "void" : W_CPPClass(space, "void", capi.C_NULL_TYPE) }
        self.cpptemplate_cache = {}
        self.cppclass_registry = {}
        self.w_clgen_callback = None

@unwrap_spec(name=str)
def resolve_name(space, name):
    return space.wrap(capi.c_resolve_name(space, name))

@unwrap_spec(name=str)
def scope_byname(space, name):
    true_name = capi.c_resolve_name(space, name)

    state = space.fromcache(State)
    try:
        return state.cppscope_cache[true_name]
    except KeyError:
        pass

    opaque_handle = capi.c_get_scope_opaque(space, true_name)
    assert lltype.typeOf(opaque_handle) == capi.C_SCOPE
    if opaque_handle:
        final_name = capi.c_final_name(space, opaque_handle)
        if capi.c_is_namespace(space, opaque_handle):
            cppscope = W_CPPNamespace(space, final_name, opaque_handle)
        elif capi.c_has_complex_hierarchy(space, opaque_handle):
            cppscope = W_ComplexCPPClass(space, final_name, opaque_handle)
        else:
            cppscope = W_CPPClass(space, final_name, opaque_handle)
        state.cppscope_cache[name] = cppscope

        cppscope._build_methods()
        cppscope._find_datamembers()
        return cppscope

    return None

@unwrap_spec(name=str)
def template_byname(space, name):
    state = space.fromcache(State)
    try:
        return state.cpptemplate_cache[name]
    except KeyError:
        pass

    opaque_handle = capi.c_get_template(space, name)
    assert lltype.typeOf(opaque_handle) == capi.C_TYPE
    if opaque_handle:
        cpptemplate = W_CPPTemplateType(space, name, opaque_handle)
        state.cpptemplate_cache[name] = cpptemplate
        return cpptemplate

    return None

def std_string_name(space):
    return space.wrap(capi.std_string_name)

@unwrap_spec(w_callback=W_Root)
def set_class_generator(space, w_callback):
    state = space.fromcache(State)
    state.w_clgen_callback = w_callback

def register_class(space, w_pycppclass):
    w_cppclass = space.findattr(w_pycppclass, space.wrap("_cpp_proxy"))
    cppclass = space.interp_w(W_CPPClass, w_cppclass, can_be_None=False)
    # add back-end specific method pythonizations (doing this on the wrapped
    # class allows simple aliasing of methods)
    capi.pythonize(space, cppclass.name, w_pycppclass)
    state = space.fromcache(State)
    state.cppclass_registry[cppclass.handle] = w_pycppclass


class W_CPPLibrary(W_Root):
    _immutable_ = True

    def __init__(self, space, cdll):
        self.cdll = cdll
        self.space = space

W_CPPLibrary.typedef = TypeDef(
    'CPPLibrary',
)
W_CPPLibrary.typedef.acceptable_as_base_class = True


class CPPMethod(object):
    """Dispatcher of methods. Checks the arguments, find the corresponding FFI
    function if available, makes the call, and returns the wrapped result. It
    also takes care of offset casting and recycling of known objects through
    the memory_regulator."""

    _attrs_ = ['space', 'scope', 'index', 'cppmethod', 'arg_defs', 'args_required',
               'args_expected', 'converters', 'executor', '_funcaddr', 'cif_descr',
               'uses_local']
    _immutable_ = True

    def __init__(self, space, containing_scope, method_index, arg_defs, args_required):
        self.space = space
        self.scope = containing_scope
        self.index = method_index
        self.cppmethod = capi.c_get_method(self.space, self.scope, method_index)
        self.arg_defs = arg_defs
        self.args_required = args_required
        self.args_expected = len(arg_defs)

        # Setup of the method dispatch's innards is done lazily, i.e. only when
        # the method is actually used.
        self.converters = None
        self.executor = None
        self.cif_descr = lltype.nullptr(jit_libffi.CIF_DESCRIPTION)
        self._funcaddr = lltype.nullptr(rffi.VOIDP.TO)
        self.uses_local = False

    def _address_from_local_buffer(self, call_local, idx):
        if not call_local:
            return call_local
        stride = 2*rffi.sizeof(rffi.VOIDP)
        loc_idx = lltype.direct_ptradd(rffi.cast(rffi.CCHARP, call_local), idx*stride)
        return rffi.cast(rffi.VOIDP, loc_idx)

    @jit.unroll_safe
    def call(self, cppthis, args_w):
        assert lltype.typeOf(cppthis) == capi.C_OBJECT

        # check number of given arguments against required (== total - defaults)
        args_expected = len(self.arg_defs)
        args_given = len(args_w)
        if args_expected < args_given or args_given < self.args_required:
            raise OperationError(self.space.w_TypeError,
                                 self.space.wrap("wrong number of arguments"))

        # initial setup of converters, executors, and libffi (if available)
        if self.converters is None:
            try:
                self._setup(cppthis)
            except Exception, e:
                pass

        # some calls, e.g. for ptr-ptr or reference need a local array to store data for
        # the duration of the call
        if self.uses_local:
            call_local = lltype.malloc(rffi.VOIDP.TO, 2*len(args_w), flavor='raw')
        else:
            call_local = lltype.nullptr(rffi.VOIDP.TO)

        try:
            # attempt to call directly through ffi chain
            if self._funcaddr:
                try:
                    return self.do_fast_call(cppthis, args_w, call_local)
                except FastCallNotPossible:
                    pass      # can happen if converters or executor does not implement ffi

            # ffi chain must have failed; using stub functions instead
            args = self.prepare_arguments(args_w, call_local)
            try:
                return self.executor.execute(self.space, self.cppmethod, cppthis, len(args_w), args)
            finally:
                self.finalize_call(args, args_w, call_local)
        finally:
            if call_local:
                lltype.free(call_local, flavor='raw')

    @jit.unroll_safe
    def do_fast_call(self, cppthis, args_w, call_local):
        if self.cif_descr == lltype.nullptr(jit_libffi.CIF_DESCRIPTION):
            raise FastCallNotPossible
        cif_descr = self.cif_descr
        buffer = lltype.malloc(rffi.CCHARP.TO, cif_descr.exchange_size, flavor='raw')
        try:
            # this pointer
            data = capi.exchange_address(buffer, cif_descr, 0)
            x = rffi.cast(rffi.LONGP, data)       # LONGP needed for test_zjit.py
            x[0] = rffi.cast(rffi.LONG, cppthis)

            # other arguments and defaults
            i = len(self.arg_defs) + 1
            for i in range(len(args_w)):
                conv = self.converters[i]
                w_arg = args_w[i]
                data = capi.exchange_address(buffer, cif_descr, i+1)
                conv.convert_argument_libffi(self.space, w_arg, data, call_local)
            for j in range(i+1, len(self.arg_defs)):
                conv = self.converters[j]
                data = capi.exchange_address(buffer, cif_descr, j+1)
                conv.default_argument_libffi(self.space, data)

            w_res = self.executor.execute_libffi(
                self.space, cif_descr, self._funcaddr, buffer)
        finally:
            lltype.free(buffer, flavor='raw')
        return w_res

    def _setup(self, cppthis):
        self.converters = [converter.get_converter(self.space, arg_type, arg_dflt)
                               for arg_type, arg_dflt in self.arg_defs]
        self.executor = executor.get_executor(
            self.space, capi.c_method_result_type(self.space, self.scope, self.index))

        for conv in self.converters:
            if conv.uses_local:
                self.uses_local = True
                break

        # Each CPPMethod corresponds one-to-one to a C++ equivalent and cppthis
        # has been offset to the matching class. Hence, the libffi pointer is
        # uniquely defined and needs to be setup only once.
        methgetter = capi.c_get_methptr_getter(self.space, self.scope, self.index)
        if methgetter and cppthis:      # methods only for now
            cif_descr = lltype.nullptr(jit_libffi.CIF_DESCRIPTION)
            try:
                funcaddr = methgetter(rffi.cast(capi.C_OBJECT, cppthis))
                self._funcaddr = rffi.cast(rffi.VOIDP, funcaddr)

                nargs = self.args_expected + 1                   # +1: cppthis

                # memory block for CIF description (note: not tracked as the life
                # time of methods is normally the duration of the application)
                size = llmemory.sizeof(jit_libffi.CIF_DESCRIPTION, nargs)

                # allocate the buffer
                cif_descr = lltype.malloc(jit_libffi.CIF_DESCRIPTION_P.TO,
                                          llmemory.raw_malloc_usage(size),
                                          flavor='raw', track_allocation=False)

                # array of 'ffi_type*' values, one per argument
                size = rffi.sizeof(jit_libffi.FFI_TYPE_P) * nargs
                atypes = lltype.malloc(rffi.CCHARP.TO, llmemory.raw_malloc_usage(size),
                                       flavor='raw', track_allocation=False)
                cif_descr.atypes = rffi.cast(jit_libffi.FFI_TYPE_PP, atypes)

                # argument type specification
                cif_descr.atypes[0] = jit_libffi.types.pointer   # cppthis
                for i, conv in enumerate(self.converters):
                    if not conv.libffitype:
                        raise FastCallNotPossible
                    cif_descr.atypes[i+1] = conv.libffitype

                # result type specification
                cif_descr.rtype = self.executor.libffitype

                # exchange ---

                # first, enough room for an array of 'nargs' pointers
                exchange_offset = rffi.sizeof(rffi.CCHARP) * nargs
                exchange_offset = (exchange_offset + 7) & ~7     # alignment
                cif_descr.exchange_result = exchange_offset
                cif_descr.exchange_result_libffi = exchange_offset

                # TODO: left this out while testing (see ctypefunc.py)
                # For results of precisely these types, libffi has a
                # strange rule that they will be returned as a whole
                # 'ffi_arg' if they are smaller.  The difference
                # only matters on big-endian.

                # then enough room for the result, rounded up to sizeof(ffi_arg)
                exchange_offset += max(rffi.getintfield(cif_descr.rtype, 'c_size'),
                                       jit_libffi.SIZE_OF_FFI_ARG)

                # loop over args
                for i in range(nargs):
                    exchange_offset = (exchange_offset + 7) & ~7 # alignment
                    cif_descr.exchange_args[i] = exchange_offset
                    exchange_offset += rffi.getintfield(cif_descr.atypes[i], 'c_size')

                # store the exchange data size
                cif_descr.exchange_size = exchange_offset

                # --- exchange

                # extra
                cif_descr.abi = clibffi.FFI_DEFAULT_ABI
                cif_descr.nargs = self.args_expected + 1         # +1: cppthis

                res = jit_libffi.jit_ffi_prep_cif(cif_descr)
                if res != clibffi.FFI_OK:
                    raise FastCallNotPossible

            except Exception, e:
                if cif_descr:
                    lltype.free(cif_descr.atypes, flavor='raw', track_allocation=False)
                    lltype.free(cif_descr, flavor='raw', track_allocation=False)
                cif_descr = lltype.nullptr(jit_libffi.CIF_DESCRIPTION)
                self._funcaddr = lltype.nullptr(rffi.VOIDP.TO)

            self.cif_descr = cif_descr

    @jit.unroll_safe
    def prepare_arguments(self, args_w, call_local):
        args = capi.c_allocate_function_args(self.space, len(args_w))
        stride = capi.c_function_arg_sizeof(self.space)
        for i in range(len(args_w)):
            conv = self.converters[i]
            w_arg = args_w[i]
            try:
                arg_i = lltype.direct_ptradd(rffi.cast(rffi.CCHARP, args), i*stride)
                loc_i = self._address_from_local_buffer(call_local, i)
                conv.convert_argument(self.space, w_arg, rffi.cast(capi.C_OBJECT, arg_i), loc_i)
            except:
                # fun :-(
                for j in range(i):
                    conv = self.converters[j]
                    arg_j = lltype.direct_ptradd(rffi.cast(rffi.CCHARP, args), j*stride)
                    loc_j = self._address_from_local_buffer(call_local, j)
                    conv.free_argument(self.space, rffi.cast(capi.C_OBJECT, arg_j), loc_j)
                capi.c_deallocate_function_args(self.space, args)
                raise
        return args

    @jit.unroll_safe
    def finalize_call(self, args, args_w, call_local):
        stride = capi.c_function_arg_sizeof(self.space)
        for i in range(len(args_w)):
            conv = self.converters[i]
            arg_i = lltype.direct_ptradd(rffi.cast(rffi.CCHARP, args), i*stride)
            loc_i = self._address_from_local_buffer(call_local, i)
            conv.finalize_call(self.space, args_w[i], loc_i)
            conv.free_argument(self.space, rffi.cast(capi.C_OBJECT, arg_i), loc_i)
        capi.c_deallocate_function_args(self.space, args)

    def signature(self):
        return capi.c_method_signature(self.space, self.scope, self.index)

    def priority(self):
        total_arg_priority = 0
        for p in [priority.get(arg_type, 0) for arg_type, arg_dflt in self.arg_defs]:
            total_arg_priority += p
        return total_arg_priority

    def __del__(self):
        if self.cif_descr:
            lltype.free(self.cif_descr.atypes, flavor='raw')
            lltype.free(self.cif_descr, flavor='raw')

    def __repr__(self):
        return "CPPMethod: %s" % self.signature()

    def _freeze_(self):
        assert 0, "you should never have a pre-built instance of this!"


class CPPFunction(CPPMethod):
    """Global (namespaced) function dispatcher. For now, the base class has
    all the needed functionality, by allowing the C++ this pointer to be null
    in the call. An optimization is expected there, however."""

    _immutable_ = True

    def __repr__(self):
        return "CPPFunction: %s" % self.signature()


class CPPTemplatedCall(CPPMethod):
    """Method dispatcher that first needs to resolve the template instance.
    Note that the derivation is from object: the CPPMethod is a data member."""

    _attrs_ = ['space', 'templ_args', 'method']
    _immutable_ = True

    def __init__(self, space, templ_args, containing_scope, method_index, arg_defs, args_required):
        self.space = space
        self.templ_args = templ_args
        # TODO: might have to specialize for CPPTemplatedCall on CPPMethod/CPPFunction here
        CPPMethod.__init__(self, space, containing_scope, method_index, arg_defs, args_required)

    def call(self, cppthis, args_w):
        assert lltype.typeOf(cppthis) == capi.C_OBJECT
        for i in range(len(args_w)):
            try:
                s = self.space.str_w(args_w[i])
            except OperationError:
                s = self.space.str_w(self.space.getattr(args_w[i], self.space.wrap('__name__')))
            s = capi.c_resolve_name(self.space, s)
            if s != self.templ_args[i]:
                raise OperationError(self.space.w_TypeError, self.space.wrap(
                    "non-matching template (got %s where %s expected" % (s, self.templ_args[i])))
        return W_CPPBoundMethod(cppthis, self)

    def bound_call(self, cppthis, args_w):
        return CPPMethod.call(self, cppthis, args_w)

    def __repr__(self):
        return "CPPTemplatedCall: %s" % self.signature()


class CPPConstructor(CPPMethod):
    """Method dispatcher that constructs new objects. This method can not have
    a fast path, a the allocation of the object is currently left to the
    reflection layer only, b/c the C++ class may have an overloaded operator
    new, disallowing malloc here."""

    _immutable_ = True

    def call(self, cppthis, args_w):
        # TODO: these casts are very, very un-pretty; need to find a way of
        # re-using CPPMethod's features w/o these roundabouts
        vscope = rffi.cast(capi.C_OBJECT, self.scope.handle)
        w_result = CPPMethod.call(self, vscope, args_w)
        newthis = rffi.cast(capi.C_OBJECT, self.space.int_w(w_result))
        return wrap_cppobject(self.space, newthis, self.scope,
                              do_cast=False, python_owns=True, fresh=True)

    def __repr__(self):
        return "CPPConstructor: %s" % self.signature()


class CPPSetItem(CPPMethod):
    """Method dispatcher specific to Python's __setitem__ mapped onto C++'s
    operator[](int). The former function takes an extra argument to assign to
    the return type of the latter."""

    _immutable_ = True

    def call(self, cppthis, args_w):
        end = len(args_w)-1
        if 0 <= end:
            w_item = args_w[end]
            args_w = args_w[:end]
            if self.converters is None:
                self._setup(cppthis)
            self.executor.set_item(self.space, w_item) # TODO: what about threads?
        CPPMethod.call(self, cppthis, args_w)


class W_CPPOverload(W_Root):
    """Dispatcher that is actually available at the app-level: it is a
    collection of (possibly) overloaded methods or functions. It calls these
    in order and deals with error handling and reporting."""

    _attrs_ = ['space', 'scope', 'functions']
    _immutable_fields_ = ['scope', 'functions[*]']

    def __init__(self, space, containing_scope, functions):
        self.space = space
        self.scope = containing_scope
        from rpython.rlib import debug
        self.functions = debug.make_sure_not_resized(functions)

    @jit.elidable_promote()
    def is_static(self):
        if isinstance(self.functions[0], CPPFunction):
            return self.space.w_True
        return self.space.w_False

    @jit.unroll_safe
    @unwrap_spec(args_w='args_w')
    def call(self, w_cppinstance, args_w):
        cppinstance = self.space.interp_w(W_CPPInstance, w_cppinstance, can_be_None=True)
        if cppinstance is not None:
            cppinstance._nullcheck()
            cppthis = cppinstance.get_cppthis(self.scope)
        else:
            cppthis = capi.C_NULL_OBJECT
        assert lltype.typeOf(cppthis) == capi.C_OBJECT

        # The following code tries out each of the functions in order. If
        # argument conversion fails (or simply if the number of arguments do
        # not match), that will lead to an exception, The JIT will snip out
        # those (always) failing paths, but only if they have no side-effects.
        # A second loop gathers all exceptions in the case all methods fail
        # (the exception gathering would otherwise be a side-effect as far as
        # the JIT is concerned).
        #
        # TODO: figure out what happens if a callback into from the C++ call
        # raises a Python exception.
        jit.promote(self)
        for i in range(len(self.functions)):
            cppyyfunc = self.functions[i]
            try:
                return cppyyfunc.call(cppthis, args_w)
            except Exception:
                pass

        # only get here if all overloads failed ...
        errmsg = 'none of the %d overloaded methods succeeded. Full details:' % len(self.functions)
        if hasattr(self.space, "fake"):     # FakeSpace fails errorstr (see below)
            raise OperationError(self.space.w_TypeError, self.space.wrap(errmsg))
        for i in range(len(self.functions)):
            cppyyfunc = self.functions[i]
            try:
                return cppyyfunc.call(cppthis, args_w)
            except OperationError, e:
                # special case if there's just one function, to prevent clogging the error message
                if len(self.functions) == 1:
                    raise
                errmsg += '\n  '+cppyyfunc.signature()+' =>\n'
                errmsg += '    '+e.errorstr(self.space)
            except Exception, e:
                # can not special case this for non-overloaded functions as we anyway need an
                # OperationError error down from here
                errmsg += '\n  '+cppyyfunc.signature()+' =>\n'
                errmsg += '    Exception: '+str(e)

        raise OperationError(self.space.w_TypeError, self.space.wrap(errmsg))

    def signature(self):
        sig = self.functions[0].signature()
        for i in range(1, len(self.functions)):
            sig += '\n'+self.functions[i].signature()
        return self.space.wrap(sig)

    def __repr__(self):
        return "W_CPPOverload(%s)" % [f.signature() for f in self.functions]

W_CPPOverload.typedef = TypeDef(
    'CPPOverload',
    is_static = interp2app(W_CPPOverload.is_static),
    call = interp2app(W_CPPOverload.call),
    signature = interp2app(W_CPPOverload.signature),
)


class W_CPPBoundMethod(W_Root):
    _attrs_ = ['cppthis', 'method']

    def __init__(self, cppthis, method):
        self.cppthis = cppthis
        self.method = method

    def __call__(self, args_w):
        return self.method.bound_call(self.cppthis, args_w)

W_CPPBoundMethod.typedef = TypeDef(
    'CPPBoundMethod',
    __call__ = interp2app(W_CPPBoundMethod.__call__),
)


class W_CPPDataMember(W_Root):
    _attrs_ = ['space', 'scope', 'converter', 'offset']
    _immutable_fields = ['scope', 'converter', 'offset']

    def __init__(self, space, containing_scope, type_name, offset):
        self.space = space
        self.scope = containing_scope
        self.converter = converter.get_converter(self.space, type_name, '')
        self.offset = offset

    def get_returntype(self):
        return self.space.wrap(self.converter.name)

    @jit.elidable_promote()
    def _get_offset(self, cppinstance):
        if cppinstance:
            assert lltype.typeOf(cppinstance.cppclass.handle) == lltype.typeOf(self.scope.handle)
            offset = self.offset + capi.c_base_offset(self.space,
                cppinstance.cppclass, self.scope, cppinstance.get_rawobject(), 1)
        else:
            offset = self.offset
        return offset

    def get(self, w_cppinstance, w_pycppclass):
        cppinstance = self.space.interp_w(W_CPPInstance, w_cppinstance, can_be_None=True)
        offset = self._get_offset(cppinstance)
        return self.converter.from_memory(self.space, w_cppinstance, w_pycppclass, offset)

    def set(self, w_cppinstance, w_value):
        cppinstance = self.space.interp_w(W_CPPInstance, w_cppinstance, can_be_None=True)
        offset = self._get_offset(cppinstance)
        self.converter.to_memory(self.space, w_cppinstance, w_value, offset)
        return self.space.w_None

W_CPPDataMember.typedef = TypeDef(
    'CPPDataMember',
    get_returntype = interp2app(W_CPPDataMember.get_returntype),
    __get__ = interp2app(W_CPPDataMember.get),
    __set__ = interp2app(W_CPPDataMember.set),
)
W_CPPDataMember.typedef.acceptable_as_base_class = False

class W_CPPStaticData(W_CPPDataMember):
    @jit.elidable_promote()
    def _get_offset(self, cppinstance):
        return self.offset

    def get(self, w_cppinstance, w_pycppclass):
        return self.converter.from_memory(self.space, self.space.w_None, w_pycppclass, self.offset)

    def set(self, w_cppinstance, w_value):
        self.converter.to_memory(self.space, self.space.w_None, w_value, self.offset)
        return self.space.w_None

W_CPPStaticData.typedef = TypeDef(
    'CPPStaticData',
    get_returntype = interp2app(W_CPPStaticData.get_returntype),
    __get__ = interp2app(W_CPPStaticData.get),
    __set__ = interp2app(W_CPPStaticData.set),
)
W_CPPStaticData.typedef.acceptable_as_base_class = False

def is_static(space, w_obj):
    try:
        space.interp_w(W_CPPStaticData, w_obj, can_be_None=False)
        return space.w_True
    except Exception:
        return space.w_False

class W_CPPScope(W_Root):
    _attrs_ = ['space', 'name', 'handle', 'methods', 'datamembers']
    _immutable_fields_ = ['kind', 'name']

    kind = "scope"

    def __init__(self, space, name, opaque_handle):
        self.space = space
        self.name = name
        assert lltype.typeOf(opaque_handle) == capi.C_SCOPE
        self.handle = opaque_handle
        self.methods = {}
        # Do not call "self._build_methods()" here, so that a distinction can
        #  be made between testing for existence (i.e. existence in the cache
        #  of classes) and actual use. Point being that a class can use itself,
        #  e.g. as a return type or an argument to one of its methods.

        self.datamembers = {}
        # Idem as for self.methods: a type could hold itself by pointer.

    def _build_methods(self):
        assert len(self.methods) == 0
        methods_temp = {}
        for i in range(capi.c_num_methods(self.space, self)):
            idx = capi.c_method_index_at(self.space, self, i)
            pyname = helper.map_operator_name(self.space,
                capi.c_method_name(self.space, self, idx),
                capi.c_method_num_args(self.space, self, idx),
                capi.c_method_result_type(self.space, self, idx))
            cppmethod = self._make_cppfunction(pyname, idx)
            methods_temp.setdefault(pyname, []).append(cppmethod)
        # the following covers the case where the only kind of operator[](idx)
        # returns are the ones that produce non-const references; these can be
        # used for __getitem__ just as much as for __setitem__, though
        if not "__getitem__" in methods_temp:
            try:
                for m in methods_temp["__setitem__"]:
                    cppmethod = self._make_cppfunction("__getitem__", m.index)
                    methods_temp.setdefault("__getitem__", []).append(cppmethod)
            except KeyError:
                pass          # just means there's no __setitem__ either

        # create the overload methods from the method sets
        for pyname, methods in methods_temp.iteritems():
            CPPMethodSort(methods).sort()
            overload = W_CPPOverload(self.space, self, methods[:])
            self.methods[pyname] = overload

    def full_name(self):
        return capi.c_scoped_final_name(self.space, self.handle)

    def get_method_names(self):
        return self.space.newlist([self.space.wrap(name) for name in self.methods])

    @jit.elidable_promote('0')
    def get_overload(self, name):
        try:
            return self.methods[name]
        except KeyError:
            pass
        new_method = self.find_overload(name)
        self.methods[name] = new_method
        return new_method

    def get_datamember_names(self):
        return self.space.newlist([self.space.wrap(name) for name in self.datamembers])

    @jit.elidable_promote('0')
    def get_datamember(self, name):
        try:
            return self.datamembers[name]
        except KeyError:
            pass
        new_dm = self.find_datamember(name)
        self.datamembers[name] = new_dm
        return new_dm

    @jit.elidable_promote('0')
    def dispatch(self, name, signature):
        overload = self.get_overload(name)
        sig = '(%s)' % signature
        for f in overload.functions:
            if 0 < f.signature().find(sig):
                return W_CPPOverload(self.space, self, [f])
        raise OperationError(self.space.w_TypeError, self.space.wrap("no overload matches signature"))

    def missing_attribute_error(self, name):
        return OperationError(
            self.space.w_AttributeError,
            self.space.wrap("%s '%s' has no attribute %s" % (self.kind, self.name, name)))

    def __eq__(self, other):
        return self.handle == other.handle

    def __ne__(self, other):
        return self.handle != other.handle


# For now, keep namespaces and classes separate as namespaces are extensible
# with info from multiple dictionaries and do not need to bother with meta
# classes for inheritance. Both are python classes, though, and refactoring
# may be in order at some point.
class W_CPPNamespace(W_CPPScope):
    _immutable_fields_ = ['kind']

    kind = "namespace"

    def _make_cppfunction(self, pyname, index):
        num_args = capi.c_method_num_args(self.space, self, index)
        args_required = capi.c_method_req_args(self.space, self, index)
        arg_defs = []
        for i in range(num_args):
            arg_type = capi.c_method_arg_type(self.space, self, index, i)
            arg_dflt = capi.c_method_arg_default(self.space, self, index, i)
            arg_defs.append((arg_type, arg_dflt))
        return CPPFunction(self.space, self, index, arg_defs, args_required)

    def _make_datamember(self, dm_name, dm_idx):
        type_name = capi.c_datamember_type(self.space, self, dm_idx)
        offset = capi.c_datamember_offset(self.space, self, dm_idx)
        datamember = W_CPPStaticData(self.space, self, type_name, offset)
        self.datamembers[dm_name] = datamember
        return datamember

    def _find_datamembers(self):
        num_datamembers = capi.c_num_datamembers(self.space, self)
        for i in range(num_datamembers):
            if not capi.c_is_publicdata(self.space, self, i):
                continue
            datamember_name = capi.c_datamember_name(self.space, self, i)
            if not datamember_name in self.datamembers:
                self._make_datamember(datamember_name, i)

    def find_overload(self, meth_name):
        indices = capi.c_method_indices_from_name(self.space, self, meth_name)
        if not indices:
            raise self.missing_attribute_error(meth_name)
        cppfunctions = []
        for meth_idx in indices:
            f = self._make_cppfunction(meth_name, meth_idx)
            cppfunctions.append(f)
        overload = W_CPPOverload(self.space, self, cppfunctions)
        return overload

    def find_datamember(self, dm_name):
        dm_idx = capi.c_datamember_index(self.space, self, dm_name)
        if dm_idx < 0:
            raise self.missing_attribute_error(dm_name)
        datamember = self._make_datamember(dm_name, dm_idx)
        return datamember

    def is_namespace(self):
        return self.space.w_True

    def ns__dir__(self):
        # Collect a list of everything (currently) available in the namespace.
        # The backend can filter by returning empty strings. Special care is
        # taken for functions, which need not be unique (overloading).
        alldir = []
        for i in range(capi.c_num_scopes(self.space, self)):
            sname = capi.c_scope_name(self.space, self, i)
            if sname: alldir.append(self.space.wrap(sname))
        allmeth = {}
        for i in range(capi.c_num_methods(self.space, self)):
            idx = capi.c_method_index_at(self.space, self, i)
            mname = capi.c_method_name(self.space, self, idx)
            if mname: allmeth.setdefault(mname, 0)
        for m in allmeth.keys():
            alldir.append(self.space.wrap(m))
        for i in range(capi.c_num_datamembers(self.space, self)):
            dname = capi.c_datamember_name(self.space, self, i)
            if dname: alldir.append(self.space.wrap(dname))
        return self.space.newlist(alldir)
        

W_CPPNamespace.typedef = TypeDef(
    'CPPNamespace',
    get_method_names = interp2app(W_CPPNamespace.get_method_names),
    get_overload = interp2app(W_CPPNamespace.get_overload, unwrap_spec=['self', str]),
    get_datamember_names = interp2app(W_CPPNamespace.get_datamember_names),
    get_datamember = interp2app(W_CPPNamespace.get_datamember, unwrap_spec=['self', str]),
    is_namespace = interp2app(W_CPPNamespace.is_namespace),
    __dir__ = interp2app(W_CPPNamespace.ns__dir__),
)
W_CPPNamespace.typedef.acceptable_as_base_class = False


class W_CPPClass(W_CPPScope):
    _attrs_ = ['space', 'default_constructor', 'name', 'handle', 'methods', 'datamembers']
    _immutable_fields_ = ['kind', 'default_constructor', 'methods[*]', 'datamembers[*]']

    kind = "class"

    def __init__(self, space, name, opaque_handle):
        W_CPPScope.__init__(self, space, name, opaque_handle)
        self.default_constructor = None

    def _make_cppfunction(self, pyname, index):
        num_args = capi.c_method_num_args(self.space, self, index)
        args_required = capi.c_method_req_args(self.space, self, index)
        arg_defs = []
        for i in range(num_args):
            arg_type = capi.c_method_arg_type(self.space, self, index, i)
            arg_dflt = capi.c_method_arg_default(self.space, self, index, i)
            arg_defs.append((arg_type, arg_dflt))
        if capi.c_is_constructor(self.space, self, index):
            cppfunction = CPPConstructor(self.space, self, index, arg_defs, args_required)
            if args_required == 0:
                self.default_constructor = cppfunction
        elif capi.c_method_is_template(self.space, self, index):
            templ_args = capi.c_template_args(self.space, self, index)
            cppfunction = CPPTemplatedCall(self.space, templ_args, self, index, arg_defs, args_required)
        elif capi.c_is_staticmethod(self.space, self, index):
            cppfunction = CPPFunction(self.space, self, index, arg_defs, args_required)
        elif pyname == "__setitem__":
            cppfunction = CPPSetItem(self.space, self, index, arg_defs, args_required)
        else:
            cppfunction = CPPMethod(self.space, self, index, arg_defs, args_required)
        return cppfunction

    def _find_datamembers(self):
        num_datamembers = capi.c_num_datamembers(self.space, self)
        for i in range(num_datamembers):
            if not capi.c_is_publicdata(self.space, self, i):
                continue
            datamember_name = capi.c_datamember_name(self.space, self, i)
            type_name = capi.c_datamember_type(self.space, self, i)
            offset = capi.c_datamember_offset(self.space, self, i)
            is_static = bool(capi.c_is_staticdata(self.space, self, i))
            if is_static:
                datamember = W_CPPStaticData(self.space, self, type_name, offset)
            else:
                datamember = W_CPPDataMember(self.space, self, type_name, offset)
            self.datamembers[datamember_name] = datamember

    def construct(self):
        if self.default_constructor is not None:
            return self.default_constructor.call(capi.C_NULL_OBJECT, [])
        raise self.missing_attribute_error("default_constructor")

    def find_overload(self, name):
        raise self.missing_attribute_error(name)

    def find_datamember(self, name):
        raise self.missing_attribute_error(name)

    def get_cppthis(self, cppinstance, calling_scope):
        assert self == cppinstance.cppclass
        return cppinstance.get_rawobject()

    def is_namespace(self):
        return self.space.w_False

    def get_base_names(self):
        bases = []
        num_bases = capi.c_num_bases(self.space, self)
        for i in range(num_bases):
            base_name = capi.c_base_name(self.space, self, i)
            bases.append(self.space.wrap(base_name))
        return self.space.newlist(bases)

W_CPPClass.typedef = TypeDef(
    'CPPClass',
    type_name = interp_attrproperty('name', W_CPPClass),
    get_base_names = interp2app(W_CPPClass.get_base_names),
    get_method_names = interp2app(W_CPPClass.get_method_names),
    get_overload = interp2app(W_CPPClass.get_overload, unwrap_spec=['self', str]),
    get_datamember_names = interp2app(W_CPPClass.get_datamember_names),
    get_datamember = interp2app(W_CPPClass.get_datamember, unwrap_spec=['self', str]),
    is_namespace = interp2app(W_CPPClass.is_namespace),
    dispatch = interp2app(W_CPPClass.dispatch, unwrap_spec=['self', str, str])
)
W_CPPClass.typedef.acceptable_as_base_class = False


class W_ComplexCPPClass(W_CPPClass):

    def get_cppthis(self, cppinstance, calling_scope):
        assert self == cppinstance.cppclass
        offset = capi.c_base_offset(self.space,
                                    self, calling_scope, cppinstance.get_rawobject(), 1)
        return capi.direct_ptradd(cppinstance.get_rawobject(), offset)

W_ComplexCPPClass.typedef = TypeDef(
    'ComplexCPPClass',
    type_name = interp_attrproperty('name', W_CPPClass),
    get_base_names = interp2app(W_ComplexCPPClass.get_base_names),
    get_method_names = interp2app(W_ComplexCPPClass.get_method_names),
    get_overload = interp2app(W_ComplexCPPClass.get_overload, unwrap_spec=['self', str]),
    get_datamember_names = interp2app(W_ComplexCPPClass.get_datamember_names),
    get_datamember = interp2app(W_ComplexCPPClass.get_datamember, unwrap_spec=['self', str]),
    is_namespace = interp2app(W_ComplexCPPClass.is_namespace),
    dispatch = interp2app(W_CPPClass.dispatch, unwrap_spec=['self', str, str])
)
W_ComplexCPPClass.typedef.acceptable_as_base_class = False


class W_CPPTemplateType(W_Root):
    _attrs_ = ['space', 'name', 'handle']
    _immutable_fields = ['name', 'handle']

    def __init__(self, space, name, opaque_handle):
        self.space = space
        self.name = name
        assert lltype.typeOf(opaque_handle) == capi.C_TYPE
        self.handle = opaque_handle

    @unwrap_spec(args_w='args_w')
    def __call__(self, args_w):
        # TODO: this is broken but unused (see pythonify.py)
        fullname = "".join([self.name, '<', self.space.str_w(args_w[0]), '>'])
        return scope_byname(self.space, fullname)

W_CPPTemplateType.typedef = TypeDef(
    'CPPTemplateType',
    __call__ = interp2app(W_CPPTemplateType.__call__),
)
W_CPPTemplateType.typedef.acceptable_as_base_class = False


class W_CPPInstance(W_Root):
    _attrs_ = ['space', 'cppclass', '_rawobject', 'isref', 'python_owns']
    _immutable_fields_ = ["cppclass", "isref"]

    def __init__(self, space, cppclass, rawobject, isref, python_owns):
        self.space = space
        self.cppclass = cppclass
        assert lltype.typeOf(rawobject) == capi.C_OBJECT
        assert not isref or rawobject
        self._rawobject = rawobject
        assert not isref or not python_owns
        self.isref = isref
        self.python_owns = python_owns

    def _nullcheck(self):
        if not self._rawobject or (self.isref and not self.get_rawobject()):
            raise OperationError(self.space.w_ReferenceError,
                                 self.space.wrap("trying to access a NULL pointer"))

    # allow user to determine ownership rules on a per object level
    def fget_python_owns(self, space):
        return space.wrap(self.python_owns)

    @unwrap_spec(value=bool)
    def fset_python_owns(self, space, value):
        self.python_owns = space.is_true(value)

    def get_cppthis(self, calling_scope):
        return self.cppclass.get_cppthis(self, calling_scope)

    def get_rawobject(self):
        if not self.isref:
            return self._rawobject
        else:
            ptrptr = rffi.cast(rffi.VOIDPP, self._rawobject)
            return rffi.cast(capi.C_OBJECT, ptrptr[0])

    def _get_as_builtin(self):
        try:
            return self.space.call_method(self.space.wrap(self), "_cppyy_as_builtin")
        except OperationError, e:
            if not (e.match(self.space, self.space.w_TypeError) or
                    e.match(self.space, self.space.w_AttributeError)):
                # TODO: TypeError is raised by call_method if the method is not found;
                # it'd be a lot nicer if only AttributeError were raise
                raise
        return None

    def instance__eq__(self, w_other):
        # special case: if other is None, compare pointer-style
        if self.space.is_w(w_other, self.space.w_None):
            return self.space.wrap(not self._rawobject)

        # get here if no class-specific overloaded operator is available, try to
        # find a global overload in gbl, in __gnu_cxx (for iterators), or in the
        # scopes of the argument classes (TODO: implement that last option)
        try:
            # TODO: expecting w_other to be an W_CPPInstance is too limiting
            other = self.space.interp_w(W_CPPInstance, w_other, can_be_None=False)
            for name in ["", "__gnu_cxx"]:
                nss = scope_byname(self.space, name)
                meth_idx = capi.c_get_global_operator(self.space, nss, self.cppclass, other.cppclass, "==")
                if meth_idx != -1:
                    f = nss._make_cppfunction("operator==", meth_idx)
                    ol = W_CPPOverload(self.space, nss, [f])
                    # TODO: cache this operator (not done yet, as the above does not
                    # select all overloads)
                    return ol.call(self, [self, w_other])
        except OperationError, e:
            if not e.match(self.space, self.space.w_TypeError):
                raise

        # fallback 1: convert the object to a builtin equivalent
        w_as_builtin = self._get_as_builtin()
        if w_as_builtin is not None:
            return self.space.eq(w_as_builtin, w_other)

        # fallback 2: direct pointer comparison (the class comparison is needed since
        # the first data member in a struct and the struct have the same address)
        other = self.space.interp_w(W_CPPInstance, w_other, can_be_None=False)  # TODO: factor out
        iseq = (self._rawobject == other._rawobject) and (self.cppclass == other.cppclass)
        return self.space.wrap(iseq)

    def instance__ne__(self, w_other):
        return self.space.not_(self.instance__eq__(w_other))

    def instance__nonzero__(self):
        if not self._rawobject or (self.isref and not self.get_rawobject()):
            return self.space.w_False
        return self.space.w_True

    def instance__len__(self):
        w_as_builtin = self._get_as_builtin()
        if w_as_builtin is not None:
            return self.space.len(w_as_builtin)
        raise OperationError(
            self.space.w_TypeError,
            self.space.wrap("'%s' has no length" % self.cppclass.name))

    def instance__cmp__(self, w_other):
        w_as_builtin = self._get_as_builtin()
        if w_as_builtin is not None:
            return self.space.cmp(w_as_builtin, w_other)
        raise OperationError(
            self.space.w_AttributeError,
            self.space.wrap("'%s' has no attribute __cmp__" % self.cppclass.name))

    def instance__repr__(self):
        w_as_builtin = self._get_as_builtin()
        if w_as_builtin is not None:
            return self.space.repr(w_as_builtin)
        return self.space.wrap("<%s object at 0x%x>" %
                               (self.cppclass.name, rffi.cast(rffi.ULONG, self.get_rawobject())))

    def destruct(self):
        assert isinstance(self, W_CPPInstance)
        if self._rawobject and not self.isref:
            memory_regulator.unregister(self)
            capi.c_destruct(self.space, self.cppclass, self._rawobject)
            self._rawobject = capi.C_NULL_OBJECT

    def __del__(self):
        if self.python_owns:
            self.enqueue_for_destruction(self.space, W_CPPInstance.destruct,
                                         '__del__() method of ')

W_CPPInstance.typedef = TypeDef(
    'CPPInstance',
    cppclass = interp_attrproperty('cppclass', cls=W_CPPInstance),
    _python_owns = GetSetProperty(W_CPPInstance.fget_python_owns, W_CPPInstance.fset_python_owns),
    __eq__ = interp2app(W_CPPInstance.instance__eq__),
    __ne__ = interp2app(W_CPPInstance.instance__ne__),
    __nonzero__ = interp2app(W_CPPInstance.instance__nonzero__),
    __len__ = interp2app(W_CPPInstance.instance__len__),
    __cmp__ = interp2app(W_CPPInstance.instance__cmp__),
    __repr__ = interp2app(W_CPPInstance.instance__repr__),
    destruct = interp2app(W_CPPInstance.destruct),
)
W_CPPInstance.typedef.acceptable_as_base_class = True


class MemoryRegulator:
    # TODO: (?) An object address is not unique if e.g. the class has a
    # public data member of class type at the start of its definition and
    # has no virtual functions. A _key class that hashes on address and
    # type would be better, but my attempt failed in the rtyper, claiming
    # a call on None ("None()") and needed a default ctor. (??)
    # Note that for now, the associated test carries an m_padding to make
    # a difference in the addresses.
    def __init__(self):
        self.objects = rweakref.RWeakValueDictionary(int, W_CPPInstance)

    def register(self, obj):
        int_address = int(rffi.cast(rffi.LONG, obj._rawobject))
        self.objects.set(int_address, obj)

    def unregister(self, obj):
        int_address = int(rffi.cast(rffi.LONG, obj._rawobject))
        self.objects.set(int_address, None)

    def retrieve(self, address):
        int_address = int(rffi.cast(rffi.LONG, address))
        return self.objects.get(int_address)

memory_regulator = MemoryRegulator()


def get_pythonized_cppclass(space, handle):
    state = space.fromcache(State)
    try:
        w_pycppclass = state.cppclass_registry[handle]
    except KeyError:
        final_name = capi.c_scoped_final_name(space, handle)
        # the callback will cache the class by calling register_class
        w_pycppclass = space.call_function(state.w_clgen_callback, space.wrap(final_name))
    return w_pycppclass

def wrap_cppobject(space, rawobject, cppclass,
                   do_cast=True, python_owns=False, is_ref=False, fresh=False):
    rawobject = rffi.cast(capi.C_OBJECT, rawobject)

    # cast to actual cast if requested and possible
    w_pycppclass = space.w_None
    if do_cast and rawobject:
        actual = capi.c_actual_class(space, cppclass, rawobject)
        if actual != cppclass.handle:
            try:
                w_pycppclass = get_pythonized_cppclass(space, actual)
                offset = capi.c_base_offset1(space, actual, cppclass, rawobject, -1)
                rawobject = capi.direct_ptradd(rawobject, offset)
                w_cppclass = space.findattr(w_pycppclass, space.wrap("_cpp_proxy"))
                cppclass = space.interp_w(W_CPPClass, w_cppclass, can_be_None=False)
            except Exception:
                # failed to locate/build the derived class, so stick to the base (note
                # that only get_pythonized_cppclass is expected to raise, so none of
                # the variables are re-assigned yet)
                pass

    if space.is_w(w_pycppclass, space.w_None):
        w_pycppclass = get_pythonized_cppclass(space, cppclass.handle)

    # try to recycle existing object if this one is not newly created
    if not fresh:
        obj = memory_regulator.retrieve(rawobject)
        if obj is not None and obj.cppclass is cppclass:
            return obj

    # fresh creation
    w_cppinstance = space.allocate_instance(W_CPPInstance, w_pycppclass)
    cppinstance = space.interp_w(W_CPPInstance, w_cppinstance, can_be_None=False)
    cppinstance.__init__(space, cppclass, rawobject, is_ref, python_owns)
    memory_regulator.register(cppinstance)
    return w_cppinstance

@unwrap_spec(w_cppinstance=W_CPPInstance)
def addressof(space, w_cppinstance):
    """Takes a bound C++ instance, returns the raw address."""
    address = rffi.cast(rffi.LONG, w_cppinstance.get_rawobject())
    return space.wrap(address)

@unwrap_spec(address=int, owns=bool)
def bind_object(space, address, w_pycppclass, owns=False):
    """Takes an address and a bound C++ class proxy, returns a bound instance."""
    rawobject = rffi.cast(capi.C_OBJECT, address)
    w_cppclass = space.findattr(w_pycppclass, space.wrap("_cpp_proxy"))
    if not w_cppclass:
        w_cppclass = scope_byname(space, space.str_w(w_pycppclass))
        if not w_cppclass:
            raise OperationError(space.w_TypeError,
                space.wrap("no such class: %s" % space.str_w(w_pycppclass)))
    cppclass = space.interp_w(W_CPPClass, w_cppclass, can_be_None=False)
    return wrap_cppobject(space, rawobject, cppclass, do_cast=False, python_owns=owns)
