# Copyright 2007 Google, Inc. All Rights Reserved.
# Licensed to PSF under a Contributor Agreement.

"""Fixer for callable().

This converts callable(obj) into isinstance(obj, collections.Callable), adding a
collections import if needed."""

# Local imports
from lib2to3 import fixer_base
from lib2to3.fixer_util import Call, Name, String, Attr, touch_import

class FixCallable(fixer_base.BaseFix):
BM_compatible = True

order = "pre"

# Ignore callable(*args) or use of keywords.
# Either could be a hint that the builtin callable() is not being used.
PATTERN = """
power< 'callable'
trailer< lpar='('
( not(arglist | argument<any '=' any>) func=any
| func=arglist<(not argument<any '=' any>) any ','> )
rpar=')' >
after=any*
>
"""

def transform(self, node, results):
func = results['func']

touch_import(None, u'collections', node=node)

args = [func.clone(), String(u', ')]
args.extend(Attr(Name(u'collections'), Name(u'Callable')))
return Call(Name(u'isinstance'), args, prefix=node.prefix)