"""Fix incompatible renames

Fixes:

  * sys.maxint -> sys.maxsize

"""

# Author: Christian Heimes

# based on Collin Winter's fix_import

# Local imports

from .. import fixer_base

from ..fixer_util import Name, attr_chain

MAPPING = {"sys":  {"maxint" : "maxsize"},

          }

LOOKUP = {}

def alternates(members):

    return "(" + "|".join(map(repr, members)) + ")"

def build_pattern():

    #bare = set()

    for module, replace in MAPPING.items():

        for old_attr, new_attr in replace.items():

            LOOKUP[(module, old_attr)] = new_attr

            #bare.add(module)

            #bare.add(old_attr)

            #yield """

            #      import_name< 'import' (module=%r

            #          | dotted_as_names< any* module=%r any* >) >

            #      """ % (module, module)

            yield """

                  import_from< 'from' module_name=%r 'import'

                      ( attr_name=%r | import_as_name< attr_name=%r 'as' any >) >

                  """ % (module, old_attr, old_attr)

            yield """

                  power< module_name=%r trailer< '.' attr_name=%r > any* >

                  """ % (module, old_attr)

    #yield """bare_name=%s""" % alternates(bare)

class FixRenames(fixer_base.BaseFix):

    PATTERN = "|".join(build_pattern())

    order = "pre" # Pre-order tree traversal

    # Don't match the node if it's within another match

    def match(self, node):

        match = super(FixRenames, self).match

        results = match(node)

        if results:

            if any([match(obj) for obj in attr_chain(node, "parent")]):

                return False

            return results

        return False

    #def start_tree(self, tree, filename):

    #    super(FixRenames, self).start_tree(tree, filename)

    #    self.replace = {}

    def transform(self, node, results):

        mod_name = results.get("module_name")

        attr_name = results.get("attr_name")

        #bare_name = results.get("bare_name")

        #import_mod = results.get("module")

        if mod_name and attr_name:

            new_attr = LOOKUP[(mod_name.value, attr_name.value)]

            attr_name.replace(Name(new_attr, prefix=attr_name.get_prefix()))