# Copyright 2014 Donald Stufft
#
# Licensed 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.
from __future__ import absolute_import, division, print_function

import bleach


ALLOWED_TAGS = [
    # Bleach Defaults
    "a", "abbr", "acronym", "b", "blockquote", "code", "em", "i", "li", "ol",
    "strong", "ul",

    # Custom Additions
    "br", "cite", "col", "colgroup", "dd", "div", "dl", "dt", "h1", "h2", "h3",
    "h4", "h5", "h6", "hr", "img", "p", "pre", "span", "table", "tbody", "td",
    "th", "thead", "tr", "tt", "kbd", "var",
]

ALLOWED_ATTRIBUTES = {
    # Bleach Defaults
    "a": ["href", "title"],
    "abbr": ["title"],
    "acronym": ["title"],

    # Custom Additions
    "*": ["id"],
    "hr": ["class"],
    "img": ["src"],
    "span": ["class"],
}

ALLOWED_STYLES = []


def clean(html, tags=None, attributes=None, styles=None):
    if tags is None:
        tags = ALLOWED_TAGS
    if attributes is None:
        attributes = ALLOWED_ATTRIBUTES
    if styles is None:
        styles = ALLOWED_STYLES

    def nofollow(attrs, new=False):
        if attrs["href"].startswith("mailto:"):
            return attrs
        attrs["rel"] = "nofollow"
        return attrs

    # Clean the output using Bleach
    cleaned = bleach.clean(
        html,
        tags=tags,
        attributes=attributes,
        styles=styles,
    )

    # Bleach Linkify makes it easy to modify links, however, we will not be
    # using it to create additional links.
    cleaned = bleach.linkify(
        cleaned,
        callbacks=[
            lambda attrs, new: attrs if not new else None,
            nofollow,
        ],
        skip_pre=True,
        parse_email=False,
    )

    return cleaned

@@ -943,16 +943,30 @@
  %22span%22,
+ %22sub%22, %22sup%22,
  %22table%22
@@ -966,16 +966,20 @@
 %22table%22,
+%0A   
  %22tbody%22
@@ -985,20 +985,16 @@
 %22, %22td%22,
-%0A   
  %22th%22, %22

Allow <sub> and <sup> tags