from __future__ import absolute_import, print_function

from mercurial import extensions

def genwrapper(x):

    def f(orig, *args, **kwds):

        return [x] + orig(*args, **kwds)

    f.x = x

    return f

def getid(wrapper):

    return getattr(wrapper, 'x', '-')

wrappers = [genwrapper(i) for i in range(5)]

class dummyclass(object):

    def getstack(self):

        return ['orig']

dummy = dummyclass()

def batchwrap(wrappers):

    for w in wrappers:

        extensions.wrapfunction(dummy, 'getstack', w)

        print('wrap %d: %s' % (getid(w), dummy.getstack()))

def batchunwrap(wrappers):

    for w in wrappers:

        result = None

        try:

            result = extensions.unwrapfunction(dummy, 'getstack', w)

            msg = str(dummy.getstack())

        except (ValueError, IndexError) as e:

            msg = e.__class__.__name__

        print('unwrap %s: %s: %s' % (getid(w), getid(result), msg))

batchwrap(wrappers + [wrappers[0]])

batchunwrap([(wrappers[i] if i >= 0 else None)

             for i in [3, None, 0, 4, 0, 2, 1, None]])