import unittest
import xml.parsers.expat
from itertools import starmap
try:
    from itertools import zip_longest
except ImportError:  # python 2.x
    from itertools import izip_longest as zip_longest
from xml.dom.minidom import Document
from xml.dom.minidom import parse
from xml.dom.minidom import parseString


def convert_to_node(doc):
    return doc.documentElement if isinstance(doc, Document) else doc

def xml_compare(left_doc, right_doc):
    left_dom = convert_to_node(left_doc)
    right_dom = convert_to_node(right_doc)

    def compare_attributes(left, right):
        return dict(left.items()) == dict(right.items())

    def node_compare(left_node, right_node):
        if left_node is None and right_node is None:
            return True
        elif left_node is None or right_node is None:
            return False

        if left_node.tagName != right_node.tagName:
            return False

        if not compare_attributes(left_node.attributes, right_node.attributes):
            return False

        nodes = zip_longest(left_node.childNodes, right_node.childNodes)
        return all(starmap(node_compare, nodes))

    return node_compare(left_dom, right_dom)


class TestDiffXML(unittest.TestCase):
    def test_node_with_ordered_attributes(self):
        dom1 = parseString('<node arg1="arg1" arg2="arg2"><item></item></node>')
        dom2 = parseString('<node arg1="arg1" arg2="arg2"><item></item></node>')
        self.assertTrue(xml_compare(dom1, dom2))

    def test_node_with_unordered_attributes(self):
        dom1 = parseString('<node arg1="arg1" arg2="arg2"><item></item></node>')
        dom2 = parseString('<node arg2="arg2" arg1="arg1"><item></item></node>')
        self.assertTrue(xml_compare(dom1, dom2))

    def test_node_with_different_attributes(self):
        dom1 = parseString('<node arg1="arg1"></node>')
        dom2 = parseString('<node arg2="arg2" arg1="arg1"><item></item></node>')
        self.assertFalse(xml_compare(dom1, dom2))

    def test_xml_only_root(self):
        dom1 = parseString("<node></node>")
        dom2 = parseString("<node></node>")
        self.assertTrue(xml_compare(dom1, dom2))

    def test_none_node(self):
        self.assertTrue(xml_compare(None, None))
        self.assertFalse(xml_compare(None, parseString("<node></node>")))
        self.assertFalse(xml_compare(parseString("<node></node>"), None))

    def test_different_xml(self):
        self.assertFalse(
            xml_compare(parseString("<left></left>"), parseString("<right></right>"))
        )

    def test_malformed_xml(self):
        with self.assertRaises(xml.parsers.expat.ExpatError):
            xml_compare(parseString("<node/>"), parseString(""))


if __name__ == "__main__":
    unittest.main(verbosity=2)