#
# Licensed to the Apache Software Foundation (ASF) under one
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# distributed with this work for additional information
# regarding copyright ownership.  The ASF licenses this file
# to you under the Apache License, Version 2.0 (the
# "License"); you may not use this file except in compliance
# with the License.  You may obtain a copy of the License at
# 
#   http://www.apache.org/licenses/LICENSE-2.0
# 
# Unless required by applicable law or agreed to in writing,
# software distributed under the License is distributed on an
# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
# KIND, either express or implied.  See the License for the
# specific language governing permissions and limitations
# under the License.
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"""
This module provides document parsing and transformation utilities for XML.
"""

from __future__ import absolute_import

import os, sys
import xml.sax, types
from xml.sax.handler import ErrorHandler
from xml.sax.xmlreader import InputSource

try:
    from io import StringIO
except ImportError:
    from cStringIO import StringIO

if sys.version_info[0] == 2:
    import types
    CLASS_TYPES = (type, types.ClassType)
else:
    CLASS_TYPES = (type,)

from . import dom
from . import transforms
from . import parsers

def transform(node, *args):
  result = node
  for t in args:
    if isinstance(t, CLASS_TYPES):
      t = t()
    result = result.dispatch(t)
  return result

class Resolver:

  def __init__(self, path):
    self.path = path

  def resolveEntity(self, publicId, systemId):
    for p in self.path:
      fname = os.path.join(p, systemId)
      if os.path.exists(fname):
        source = InputSource(systemId)
        source.setByteStream(open(fname))
        return source
    return InputSource(systemId)

def xml_parse(filename, path=()):
  if sys.version_info[0:2] == (2,3):
    # XXX: this is for older versions of python
    source = "file://%s" % os.path.abspath(filename)
  else:
    source = filename
  h = parsers.XMLParser()
  p = xml.sax.make_parser()
  p.setContentHandler(h)
  p.setErrorHandler(ErrorHandler())
  p.setEntityResolver(Resolver(path))
  p.parse(source)
  return h.parser.tree

def sexp(node):
  s = transforms.Sexp()
  node.dispatch(s)
  return s.out