"""
    deprecated class from scikit-learn package
    https://github.com/scikit-learn/scikit-learn/blob/master/sklearn/utils/deprecation.py
"""

import sys
import warnings

__all__ = ["deprecated", ]


class deprecated(object):
    """Decorator to mark a function or class as deprecated.
    Issue a warning when the function is called/the class is instantiated and
    adds a warning to the docstring.
    The optional extra argument will be appended to the deprecation message
    and the docstring. Note: to use this with the default value for extra, put
    in an empty of parentheses:
    >>> from ot.deprecation import deprecated
    >>> @deprecated()
    ... def some_function(): pass

    Parameters
    ----------
    extra : string
          to be added to the deprecation messages
    """

    # Adapted from http://wiki.python.org/moin/PythonDecoratorLibrary,
    # but with many changes.

    def __init__(self, extra=''):
        self.extra = extra

    def __call__(self, obj):
        """Call method
        Parameters
        ----------
        obj : object
        """
        if isinstance(obj, type):
            return self._decorate_class(obj)
        else:
            return self._decorate_fun(obj)

    def _decorate_class(self, cls):
        msg = "Class %s is deprecated" % cls.__name__
        if self.extra:
            msg += "; %s" % self.extra

        # FIXME: we should probably reset __new__ for full generality
        init = cls.__init__

        def wrapped(*args, **kwargs):
            warnings.warn(msg, category=DeprecationWarning)
            return init(*args, **kwargs)

        cls.__init__ = wrapped

        wrapped.__name__ = '__init__'
        wrapped.__doc__ = self._update_doc(init.__doc__)
        wrapped.deprecated_original = init

        return cls

    def _decorate_fun(self, fun):
        """Decorate function fun"""

        msg = "Function %s is deprecated" % fun.__name__
        if self.extra:
            msg += "; %s" % self.extra

        def wrapped(*args, **kwargs):
            warnings.warn(msg, category=DeprecationWarning)
            return fun(*args, **kwargs)

        wrapped.__name__ = fun.__name__
        wrapped.__dict__ = fun.__dict__
        wrapped.__doc__ = self._update_doc(fun.__doc__)

        return wrapped

    def _update_doc(self, olddoc):
        newdoc = "DEPRECATED"
        if self.extra:
            newdoc = "%s: %s" % (newdoc, self.extra)
        if olddoc:
            newdoc = "%s\n\n%s" % (newdoc, olddoc)
        return newdoc


def _is_deprecated(func):
    """Helper to check if func is wraped by our deprecated decorator"""
    if sys.version_info < (3, 5):
        raise NotImplementedError("This is only available for python3.5 "
                                  "or above")
    closures = getattr(func, '__closure__', [])
    if closures is None:
        closures = []
    is_deprecated = ('deprecated' in ''.join([c.cell_contents
                                              for c in closures
                     if isinstance(c.cell_contents, str)]))
    return is_deprecated