-# -*- coding: utf-8 -*-
-from __future__ import unicode_literals
-
+# This file is part of Librarian, licensed under GNU Affero GPLv3 or later.
+# Copyright © Fundacja Wolne Lektury. See NOTICE for more information.
+#
 from operator import and_
-
+import functools
+import io
 from .dcparser import Field, WorkInfo, DCNS
 from librarian import (RDFNS, ValidationError, NoDublinCore, ParseError, WLURI)
 from xml.parsers.expat import ExpatError
 from lxml import etree
 from lxml.etree import (XMLSyntaxError, XSLTApplyError, Element)
 import re
-import six
 
 
 class WLPictureURI(WLURI):
-    _re_wl_uri = re.compile('http://wolnelektury.pl/katalog/obraz/(?P<slug>[-a-z0-9]+)/?$')
-
-    @classmethod
-    def from_slug(cls, slug):
-        uri = 'http://wolnelektury.pl/katalog/obraz/%s/' % slug
-        return cls(uri)
+    _re_wl_uri = re.compile(
+        'http://wolnelektury.pl/katalog/obraz/(?P<slug>[-a-z0-9]+)/?$'
+    )
+    template = 'http://wolnelektury.pl/katalog/obraz/%s/'
 
 
 def as_wlpictureuri_strict(text):
         Field(DCNS('language'), 'language', required=False),
         Field(DCNS('subject.period'), 'epochs', salias='epoch', multiple=True),
         Field(DCNS('subject.type'), 'kinds', salias='kind', multiple=True),
-        Field(DCNS('subject.genre'), 'genres', salias='genre', multiple=True, required=False),
-        Field(DCNS('subject.style'), 'styles', salias='style', multiple=True, required=False),
+        Field(DCNS('subject.genre'), 'genres', salias='genre', multiple=True,
+              required=False),
+        Field(DCNS('subject.style'), 'styles', salias='style', multiple=True,
+              required=False),
 
         Field(DCNS('format.dimensions'), 'dimensions', required=False),
         Field(DCNS('format.checksum.sha1'), 'sha1', required=True),
         Field(DCNS('description.medium'), 'medium', required=False),
-        Field(DCNS('description.dimensions'), 'original_dimensions', required=False),
+        Field(DCNS('description.dimensions'), 'original_dimensions',
+              required=False),
         Field(DCNS('format'), 'mime_type', required=False),
-        Field(DCNS('identifier.url'), 'url', WLPictureURI, strict=as_wlpictureuri_strict)
+        Field(DCNS('identifier.url'), 'url', WLPictureURI,
+              strict=as_wlpictureuri_strict)
     )
 
 
-class ImageStore(object):
+class ImageStore:
     EXT = ['gif', 'jpeg', 'png', 'swf', 'psd', 'bmp'
            'tiff', 'tiff', 'jpc', 'jp2', 'jpf', 'jb2', 'swc',
            'aiff', 'wbmp', 'xbm']
     MIME = ['image/gif', 'image/jpeg', 'image/png',
             'application/x-shockwave-flash', 'image/psd', 'image/bmp',
             'image/tiff', 'image/tiff', 'application/octet-stream',
-            'image/jp2', 'application/octet-stream', 'application/octet-stream',
-            'application/x-shockwave-flash', 'image/iff', 'image/vnd.wap.wbmp', 'image/xbm']
+            'image/jp2', 'application/octet-stream',
+            'application/octet-stream', 'application/x-shockwave-flash',
+            'image/iff', 'image/vnd.wap.wbmp', 'image/xbm']
 
     def __init__(self, dir_):
         super(ImageStore, self).__init__()
         try:
             i = self.MIME.index(mime_type)
         except ValueError:
-            err = ValueError("Picture %s has unknown mime type: %s" % (slug, mime_type))
+            err = ValueError(
+                "Picture %s has unknown mime type: %s"
+                % (slug, mime_type)
+            )
             err.slug = slug
             err.mime_type = mime_type
             raise err
         return path.join(self.dir, slug + '.' + ext)
 
 
-class WLPicture(object):
+class WLPicture:
     def __init__(self, edoc, parse_dublincore=True, image_store=None):
         self.edoc = edoc
         self.image_store = image_store
         dc_path = './/' + RDFNS('RDF')
 
         if root_elem.tag != 'picture':
-            raise ValidationError("Invalid root element. Found '%s', should be 'picture'" % root_elem.tag)
+            raise ValidationError(
+                "Invalid root element. Found '%s', should be 'picture'"
+                % root_elem.tag
+            )
 
         if parse_dublincore:
             self.rdf_elem = root_elem.find(dc_path)
 
             if self.rdf_elem is None:
-                raise NoDublinCore('Document has no DublinCore - which is required.')
+                raise NoDublinCore(
+                    "Document has no DublinCore - which is required."
+                )
 
             self.picture_info = PictureInfo.from_element(self.rdf_elem)
         else:
 
     @classmethod
     def from_bytes(cls, xml, *args, **kwargs):
-        return cls.from_file(six.BytesIO(xml), *args, **kwargs)
+        return cls.from_file(io.BytesIO(xml), *args, **kwargs)
 
     @classmethod
     def from_file(cls, xmlfile, parse_dublincore=True, image_store=None):
 
         # first, prepare for parsing
-        if isinstance(xmlfile, six.text_type):
+        if isinstance(xmlfile, str):
             file = open(xmlfile, 'rb')
             try:
                 data = file.read()
         else:
             data = xmlfile.read()
 
-        if not isinstance(data, six.text_type):
+        if not isinstance(data, str):
             data = data.decode('utf-8')
 
-        data = data.replace(u'\ufeff', '')
+        data = data.replace('\ufeff', '')
 
         # assume images are in the same directory
         if image_store is None and getattr(xmlfile, 'name', None):
 
         try:
             parser = etree.XMLParser(remove_blank_text=False)
-            tree = etree.parse(six.BytesIO(data.encode('utf-8')), parser)
+            tree = etree.parse(io.BytesIO(data.encode('utf-8')), parser)
 
-            me = cls(tree, parse_dublincore=parse_dublincore, image_store=image_store)
+            me = cls(tree, parse_dublincore=parse_dublincore,
+                     image_store=image_store)
             me.load_frame_info()
             return me
         except (ExpatError, XMLSyntaxError, XSLTApplyError) as e:
     @property
     def mime_type(self):
         if self.picture_info is None:
-            raise ValueError('DC is not loaded, hence we don\'t know the image type')
+            raise ValueError(
+                "DC is not loaded, hence we don't know the image type."
+            )
         return self.picture_info.mime_type
 
     @property
             return [[0, 0], [-1, -1]]
 
         def has_all_props(node, props):
-            return reduce(and_, map(lambda prop: prop in node.attrib, props))
+            return functools.reduce(
+                and_, map(lambda prop: prop in node.attrib, props)
+            )
 
         if not has_all_props(area, ['x1', 'x2', 'y1', 'y2']):
             return None
 
     def partiter(self):
         """
-        Iterates the parts of this picture and returns them and their metadata
+        Iterates the parts of this picture and returns them
+        and their metadata.
         """
         # omg no support for //sem[(@type='theme') or (@type='object')] ?
         for part in list(self.edoc.iterfind("//sem[@type='theme']")) +\
             pd['coords'] = coords
 
             def want_unicode(x):
-                if not isinstance(x, six.text_type):
+                if not isinstance(x, str):
                     return x.decode('utf-8')
                 else:
                     return x
-            pd['object'] = part.attrib['type'] == 'object' and want_unicode(part.attrib.get('object', u'')) or None
-            pd['themes'] = part.attrib['type'] == 'theme' and [part.attrib.get('theme', u'')] or []
+            pd['object'] = (
+                part.attrib['type'] == 'object'
+                and want_unicode(part.attrib.get('object', ''))
+                or None
+            )
+            pd['themes'] = (
+                part.attrib['type'] == 'theme'
+                and [part.attrib.get('theme', '')]
+                or []
+            )
             yield pd
 
     def load_frame_info(self):
         k = self.edoc.find("//sem[@object='kadr']")
-        
+
         if k is not None:
             clip = self.get_sem_coords(k)
             self.frame = clip
             frm = Element("sem", {"type": "frame"})
-            frm.append(k.iter("div").next())
+            frm.append(next(k.iter("div")))
             self.edoc.getroot().append(frm)
             k.getparent().remove(k)
         else: