# coding: utf-8
"""
Fixer for the cmp() function on Py2, which was removed in Py3.

Adds this import line::

    from past.builtins import cmp

if cmp() is called in the code.
"""

from __future__ import unicode_literals
from lib2to3 import fixer_base

from libfuturize.fixer_util import touch_import_top


expression = "name='cmp'"


class FixCmp(fixer_base.BaseFix):
    BM_compatible = True
    run_order = 9

    PATTERN = """
              power<
                 ({0}) trailer< '(' args=[any] ')' >
              rest=any* >
              """.format(expression)

    def transform(self, node, results):
        name = results["name"]
        touch_import_top(u'past.builtins', name.value, node)