# Source code for PIL.ImageMath

    #
    # The Python Imaging Library
    # $Id$
    #
    # a simple math add-on for the Python Imaging Library
    #
    # History:
    # 1999-02-15 fl   Original PIL Plus release
    # 2005-05-05 fl   Simplified and cleaned up for PIL 1.1.6
    # 2005-09-12 fl   Fixed int() and float() for Python 2.4.1
    #
    # Copyright (c) 1999-2005 by Secret Labs AB
    # Copyright (c) 2005 by Fredrik Lundh
    #
    # See the README file for information on usage and redistribution.
    #

    import builtins

    from . import Image, _imagingmath

    VERBOSE = 0

    def _isconstant(v):
        return isinstance(v, (int, float))

    class _Operand:
        """Wraps an image operand, providing standard operators"""

        def __init__(self, im):
            self.im = im

        def __fixup(self, im1):
            # convert image to suitable mode
            if isinstance(im1, _Operand):
                # argument was an image.
                if im1.im.mode in ("1", "L"):
                    return im1.im.convert("I")
                elif im1.im.mode in ("I", "F"):
                    return im1.im
                else:
                    raise ValueError(f"unsupported mode: {im1.im.mode}")
            else:
                # argument was a constant
                if _isconstant(im1) and self.im.mode in ("1", "L", "I"):
                    return Image.new("I", self.im.size, im1)
                else:
                    return Image.new("F", self.im.size, im1)

        def apply(self, op, im1, im2=None, mode=None):
            im1 = self.__fixup(im1)
            if im2 is None:
                # unary operation
                out = Image.new(mode or im1.mode, im1.size, None)
                im1.load()
                try:
                    op = getattr(_imagingmath, op + "_" + im1.mode)
                except AttributeError as e:
                    raise TypeError(f"bad operand type for '{op}'") from e
                _imagingmath.unop(op, out.im.id, im1.im.id)
            else:
                # binary operation
                im2 = self.__fixup(im2)
                if im1.mode != im2.mode:
                    # convert both arguments to floating point
                    if im1.mode != "F":
                        im1 = im1.convert("F")
                    if im2.mode != "F":
                        im2 = im2.convert("F")
                    if im1.mode != im2.mode:
                        raise ValueError("mode mismatch")
                if im1.size != im2.size:
                    # crop both arguments to a common size
                    size = (min(im1.size[0], im2.size[0]), min(im1.size[1], im2.size[1]))
                    if im1.size != size:
                        im1 = im1.crop((0, 0) + size)
                    if im2.size != size:
                        im2 = im2.crop((0, 0) + size)
                    out = Image.new(mode or im1.mode, size, None)
                else:
                    out = Image.new(mode or im1.mode, im1.size, None)
                im1.load()
                im2.load()
                try:
                    op = getattr(_imagingmath, op + "_" + im1.mode)
                except AttributeError as e:
                    raise TypeError(f"bad operand type for '{op}'") from e
                _imagingmath.binop(op, out.im.id, im1.im.id, im2.im.id)
            return _Operand(out)

        # unary operators
        def __bool__(self):
            # an image is "true" if it contains at least one non-zero pixel
            return self.im.getbbox() is not None

        def __abs__(self):
            return self.apply("abs", self)

        def __pos__(self):
            return self

        def __neg__(self):
            return self.apply("neg", self)

        # binary operators
        def __add__(self, other):
            return self.apply("add", self, other)

        def __radd__(self, other):
            return self.apply("add", other, self)

        def __sub__(self, other):
            return self.apply("sub", self, other)

        def __rsub__(self, other):
            return self.apply("sub", other, self)

        def __mul__(self, other):
            return self.apply("mul", self, other)

        def __rmul__(self, other):
            return self.apply("mul", other, self)

        def __truediv__(self, other):
            return self.apply("div", self, other)

        def __rtruediv__(self, other):
            return self.apply("div", other, self)

        def __mod__(self, other):
            return self.apply("mod", self, other)

        def __rmod__(self, other):
            return self.apply("mod", other, self)

        def __pow__(self, other):
            return self.apply("pow", self, other)

        def __rpow__(self, other):
            return self.apply("pow", other, self)

        # bitwise
        def __invert__(self):
            return self.apply("invert", self)

        def __and__(self, other):
            return self.apply("and", self, other)

        def __rand__(self, other):
            return self.apply("and", other, self)

        def __or__(self, other):
            return self.apply("or", self, other)

        def __ror__(self, other):
            return self.apply("or", other, self)

        def __xor__(self, other):
            return self.apply("xor", self, other)

        def __rxor__(self, other):
            return self.apply("xor", other, self)

        def __lshift__(self, other):
            return self.apply("lshift", self, other)

        def __rshift__(self, other):
            return self.apply("rshift", self, other)

        # logical
        def __eq__(self, other):
            return self.apply("eq", self, other)

        def __ne__(self, other):
            return self.apply("ne", self, other)

        def __lt__(self, other):
            return self.apply("lt", self, other)

        def __le__(self, other):
            return self.apply("le", self, other)

        def __gt__(self, other):
            return self.apply("gt", self, other)

        def __ge__(self, other):
            return self.apply("ge", self, other)

    # conversions
    def imagemath_int(self):
        return _Operand(self.im.convert("I"))

    def imagemath_float(self):
        return _Operand(self.im.convert("F"))

    # logical
    def imagemath_equal(self, other):
        return self.apply("eq", self, other, mode="I")

    def imagemath_notequal(self, other):
        return self.apply("ne", self, other, mode="I")

    def imagemath_min(self, other):
        return self.apply("min", self, other)

    def imagemath_max(self, other):
        return self.apply("max", self, other)

    def imagemath_convert(self, mode):
        return _Operand(self.im.convert(mode))

    ops = {}
    for k, v in list(globals().items()):
        if k[:10] == "imagemath_":
            ops[k[10:]] = v

    def eval(expression, _dict={}, **kw):
        """
        Evaluates an image expression.

        :param expression: A string containing a Python-style expression.
        :param options: Values to add to the evaluation context.  You
                        can either use a dictionary, or one or more keyword
                        arguments.
        :return: The evaluated expression. This is usually an image object, but can
                 also be an integer, a floating point value, or a pixel tuple,
                 depending on the expression.
        """

        # build execution namespace
        args = ops.copy()
        for k in list(_dict.keys()) + list(kw.keys()):
            if "__" in k or hasattr(builtins, k):
                msg = f"'{k}' not allowed"
                raise ValueError(msg)

        args.update(_dict)
        args.update(kw)
        for k, v in list(args.items()):
            if hasattr(v, "im"):
                args[k] = _Operand(v)

        compiled_code = compile(expression, "<string>", "eval")

        def scan(code):
            for const in code.co_consts:
                if type(const) == type(compiled_code):
                    scan(const)

            for name in code.co_names:
                if name not in args and name != "abs":
                    raise ValueError(f"'{name}' not allowed")

        scan(compiled_code)
        out = builtins.eval(expression, {"__builtins": {"abs": abs}}, args)
        try:
            return out.im
        except AttributeError:
            return out