"""
A backport of Python 3 functools to Python 2/3. The only important change
we rely upon is that `update_wrapper` handles AttributeError gracefully.
"""

from functools import partial

from sentry_sdk._types import MYPY

if MYPY:
    from typing import Any
    from typing import Callable


WRAPPER_ASSIGNMENTS = (
    "__module__",
    "__name__",
    "__qualname__",
    "__doc__",
    "__annotations__",
)
WRAPPER_UPDATES = ("__dict__",)


def update_wrapper(
    wrapper, wrapped, assigned=WRAPPER_ASSIGNMENTS, updated=WRAPPER_UPDATES
):
    # type: (Any, Any, Any, Any) -> Any
    """Update a wrapper function to look like the wrapped function

    wrapper is the function to be updated
    wrapped is the original function
    assigned is a tuple naming the attributes assigned directly
    from the wrapped function to the wrapper function (defaults to
    functools.WRAPPER_ASSIGNMENTS)
    updated is a tuple naming the attributes of the wrapper that
    are updated with the corresponding attribute from the wrapped
    function (defaults to functools.WRAPPER_UPDATES)
    """
    for attr in assigned:
        try:
            value = getattr(wrapped, attr)
        except AttributeError:
            pass
        else:
            setattr(wrapper, attr, value)
    for attr in updated:
        getattr(wrapper, attr).update(getattr(wrapped, attr, {}))
    # Issue #17482: set __wrapped__ last so we don't inadvertently copy it
    # from the wrapped function when updating __dict__
    wrapper.__wrapped__ = wrapped
    # Return the wrapper so this can be used as a decorator via partial()
    return wrapper


def wraps(wrapped, assigned=WRAPPER_ASSIGNMENTS, updated=WRAPPER_UPDATES):
    # type: (Callable[..., Any], Any, Any) -> Callable[[Callable[..., Any]], Callable[..., Any]]
    """Decorator factory to apply update_wrapper() to a wrapper function

    Returns a decorator that invokes update_wrapper() with the decorated
    function as the wrapper argument and the arguments to wraps() as the
    remaining arguments. Default arguments are as for update_wrapper().
    This is a convenience function to simplify applying partial() to
    update_wrapper().
    """
    return partial(update_wrapper, wrapped=wrapped, assigned=assigned, updated=updated)