import collections
import itertools
import xml.etree.ElementTree as ET
import xml.sax.saxutils as sax
from uuid import uuid4

from tableaudocumentapi import Connection, xfile
from tableaudocumentapi import Field
from tableaudocumentapi.multilookup_dict import MultiLookupDict
from tableaudocumentapi.xfile import xml_open

########
# This is needed in order to determine if something is a string or not.  It is necessary because
# of differences between python2 (basestring) and python3 (str).  If python2 support is ever
# dropped, remove this and change the basestring references below to str
try:
    basestring
except NameError:  # pragma: no cover
    basestring = str
########

_ColumnObjectReturnTuple = collections.namedtuple('_ColumnObjectReturnTupleType', ['id', 'object'])


def _get_metadata_xml_for_field(root_xml, field_name):
    if "'" in field_name:
        field_name = sax.escape(field_name, {"'": "'"})
    xpath = u".//metadata-record[@class='column'][local-name='{}']".format(field_name)
    return root_xml.find(xpath)


def _is_used_by_worksheet(names, field):
    return any(y for y in names if y in field.worksheets)


class FieldDictionary(MultiLookupDict):

    def used_by_sheet(self, name):
        # If we pass in a string, no need to get complicated, just check to see if name is in
        # the field's list of worksheets
        if isinstance(name, basestring):
            return [x for x in self.values() if name in x.worksheets]

        # if we pass in a list, we need to check to see if any of the names in the list are in
        # the field's list of worksheets
        return [x for x in self.values() if _is_used_by_worksheet(name, x)]


def _column_object_from_column_xml(root_xml, column_xml):
    field_object = Field.from_column_xml(column_xml)
    local_name = field_object.id
    metadata_record = _get_metadata_xml_for_field(root_xml, local_name)
    if metadata_record is not None:
        field_object.apply_metadata(metadata_record)
    return _ColumnObjectReturnTuple(field_object.id, field_object)


def _column_object_from_metadata_xml(metadata_xml):
    field_object = Field.from_metadata_xml(metadata_xml)
    return _ColumnObjectReturnTuple(field_object.id, field_object)


def base36encode(number):
    """Converts an integer into a base36 string."""

    ALPHABET = "0123456789abcdefghijklmnopqrstuvwxyz"

    base36 = ''
    sign = ''

    if number < 0:
        sign = '-'
        number = -number

    if 0