from marshmallow import Schema, fields
from marshmallow.utils import get_value, set_value


class Reach(fields.Field):
    """
    Solution suggested by marshmallow community
    https://github.com/marshmallow-code/marshmallow/pull/1298#issuecomment-513314792

    class MySchema(Schema):
    foo = fields.Str()
    bar = Reach(fields.Int(), data_key="data", path="bar.baz")

    data = {"foo": "dotted", "data": {"bar": {"baz": "42"}}}
    schema = MySchema()
    loaded = schema.load(data)

    loaded:  {'foo': 'dotted', 'bar': 42}
    dumped:  {'foo': 'dotted', 'data': {'bar': {'baz': 42}}}
    """
    def __init__(self, inner, path, **kwargs):
        super().__init__(**kwargs)
        self.inner = inner
        self.path = path

    def _deserialize(self, value, attr, data, **kwargs):
        val = get_value(value, self.path)
        return self.inner.deserialize(val, **kwargs)

    def _serialize(self, value, attr, obj, **kwargs):
        val = self.inner._serialize(value, attr, obj, **kwargs)
        ret = {}
        set_value(ret, self.path, val)
        return ret