# -*- coding: utf-8 -*-
#
# Copyright (C) Pootle contributors.
#
# This file is a part of the Pootle project. It is distributed under the GPL3
# or later license. See the LICENSE file for a copy of the license and the
# AUTHORS file for copyright and authorship information.


class BaseProxy(object):
    """Base Proxy class to wrap an object"""

    __slots__ = ["_obj", "__weakref__"]

    def __init__(self, obj):
        object.__setattr__(self, "_obj", obj)

    def __getattribute__(self, name):
        return getattr(object.__getattribute__(self, "_obj"), name)

    def __delattr__(self, name):
        delattr(object.__getattribute__(self, "_obj"), name)

    def __setattr__(self, name, value):
        setattr(object.__getattribute__(self, "_obj"), name, value)

    def __nonzero__(self):
        return bool(object.__getattribute__(self, "_obj"))

    def __str__(self):
        return str(object.__getattribute__(self, "_obj"))

    _special_names = [
        '__abs__', '__add__', '__and__', '__call__', '__cmp__', '__coerce__',
        '__contains__', '__delitem__', '__delslice__', '__div__', '__divmod__',
        '__eq__', '__float__', '__floordiv__', '__ge__', '__getitem__',
        '__getslice__', '__gt__', '__hash__', '__hex__', '__iadd__', '__iand__',
        '__idiv__', '__idivmod__', '__ifloordiv__', '__ilshift__', '__imod__',
        '__imul__', '__int__', '__invert__', '__ior__', '__ipow__', '__irshift__',
        '__isub__', '__iter__', '__itruediv__', '__ixor__', '__le__', '__len__',
        '__long__', '__lshift__', '__lt__', '__mod__', '__mul__', '__ne__',
        '__neg__', '__oct__', '__or__', '__pos__', '__pow__', '__radd__',
        '__rand__', '__rdiv__', '__rdivmod__', '__reduce__', '__reduce_ex__',
        '__repr__', '__reversed__', '__rfloorfiv__', '__rlshift__', '__rmod__',
        '__rmul__', '__ror__', '__rpow__', '__rrshift__', '__rshift__', '__rsub__',
        '__rtruediv__', '__rxor__', '__setitem__', '__setslice__', '__sub__',
        '__truediv__', '__xor__', 'next',
    ]

    @classmethod
    def _create_class_proxy(cls, theclass):
        """creates a proxy for the given class"""

        def make_method(name):
            def method(self, *args, **kw):
                _method = getattr(
                    object.__getattribute__(self, "_obj"), name)
                return _method(*args, **kw)
            return method

        namespace = {}
        for name in cls._special_names:
            if hasattr(theclass, name):
                namespace[name] = make_method(name)
        return type("%s(%s)" % (cls.__name__, theclass.__name__), (cls,), namespace)

    def __new__(cls, obj, *args, **kwargs):
        """
        creates an proxy instance referencing `obj`. (obj, *args, **kwargs) are
        passed to this class' __init__, so deriving classes can define an
        __init__ method of their own.
        note: _class_proxy_cache is unique per deriving class (each deriving
        class must hold its own cache)
        """
        try:
            cache = cls.__dict__["_class_proxy_cache"]
        except KeyError:
            cls._class_proxy_cache = cache = {}
        try:
            theclass = cache[obj.__class__]
        except KeyError:
            cache[obj.__class__] = theclass = cls._create_class_proxy(obj.__class__)
        ins = object.__new__(theclass)
        theclass.__init__(ins, obj, *args, **kwargs)
        return ins


class AttributeProxy(BaseProxy):
    """Wraps an object, but allows getting setting of attributes on wrapper"""

    def __getattribute__(self, name):
        obj = object.__getattribute__(self, "_obj")
        if hasattr(obj, name):
            return getattr(obj, name)
        return object.__getattribute__(self, name)

    def __setattr__(self, name, value):
        obj = object.__getattribute__(self, "_obj")
        if hasattr(obj, name):
            setattr(obj, name, value)
        object.__setattr__(self, name, value)

    def __delattr__(self, name):
        obj = object.__getattribute__(self, "_obj")
        if hasattr(obj, name):
            delattr(obj, name)
        object.__delattr__(self, name)
