if repo is None:

                            repo = user_log.repository.scm_instance

                        _rev = repo.get_changeset(rev)

                        revs.append(_rev)

                    except ChangesetDoesNotExistError:

                        log.error('cannot find revision %s in this repo', rev)

                        revs.append(rev)

                else:

                    _rev = AttributeDict({

                        'short_id': rev[:12],

                        'raw_id': rev,

                        'message': '',

                        'op': _op,

                        'ref_name': _name

                    })

                    revs.append(_rev)

        cs_links = [" " + ', '.join(

            [lnk(rev, repo_name) for rev in revs[:revs_limit]]

        )]

        _op1, _name1 = _get_op(revs_ids[0])

        _op2, _name2 = _get_op(revs_ids[-1])

        _rev = '%s...%s' % (_name1, _name2)

        compare_view = (

            ' <div class="compare_view" data-toggle="tooltip" title="%s">'

            '<a href="%s">%s</a> </div>' % (

                _('Show all combined changesets %s->%s') % (

                    revs_ids[0][:12], revs_ids[-1][:12]

                ),

                url('changeset_home', repo_name=repo_name,

                    revision=_rev

                ),

                _('Compare view')

            )

        )

        # if we have exactly one more than normally displayed

        # just display it, takes less space than displaying

        # "and 1 more revisions"

        if len(revs_ids) == revs_limit + 1:

            cs_links.append(", " + lnk(revs[revs_limit], repo_name))

        # hidden-by-default ones

        if len(revs_ids) > revs_limit + 1:

            uniq_id = revs_ids[0]

            html_tmpl = (

                '<span> %s <a class="show_more" id="_%s" '

                'href="#more">%s</a> %s</span>'

            )

            if not feed:

                cs_links.append(html_tmpl % (

                      _('and'),

                      uniq_id, _('%s more') % (len(revs_ids) - revs_limit),

                      _('revisions')

                    )

                )

            if not feed:

                html_tmpl = '<span id="%s" style="display:none">, %s </span>'

            else:

                html_tmpl = '<span id="%s"> %s </span>'

            morelinks = ', '.join(

              [lnk(rev, repo_name) for rev in revs[revs_limit:]]

            )

            if len(revs_ids) > revs_top_limit:

                morelinks += ', ...'

            cs_links.append(html_tmpl % (uniq_id, morelinks))

        if len(revs) > 1:

            cs_links.append(compare_view)

        return ''.join(cs_links)

    def get_fork_name():

        repo_name = action_params

        url_ = url('summary_home', repo_name=repo_name)

        return _('Fork name %s') % link_to(action_params, url_)

    def get_user_name():

        user_name = action_params

        return user_name

    def get_users_group():

        group_name = action_params

        return group_name

    def get_pull_request():

        from kallithea.model.db import PullRequest

        pull_request_id = action_params

        nice_id = PullRequest.make_nice_id(pull_request_id)

        deleted = user_log.repository is None

        if deleted:

            repo_name = user_log.repository_name

        else:

            repo_name = user_log.repository.repo_name

        return link_to(_('Pull request %s') % nice_id,

                    url('pullrequest_show', repo_name=repo_name,

                    pull_request_id=pull_request_id))

    def get_archive_name():

        archive_name = action_params

        return archive_name

    # action : translated str, callback(extractor), icon

    action_map = {

        'user_deleted_repo':           (_('[deleted] repository'),

                                        None, 'icon-trashcan'),

        'user_created_repo':           (_('[created] repository'),

                                        None, 'icon-plus'),

        'user_created_fork':           (_('[created] repository as fork'),

                                        None, 'icon-fork'),

        'user_forked_repo':            (_('[forked] repository'),

                                        get_fork_name, 'icon-fork'),

        'user_updated_repo':           (_('[updated] repository'),

                                        None, 'icon-pencil'),

        'user_downloaded_archive':      (_('[downloaded] archive from repository'),

                                        get_archive_name, 'icon-download-cloud'),

        'admin_deleted_repo':          (_('[delete] repository'),

                                        None, 'icon-trashcan'),

        'admin_created_repo':          (_('[created] repository'),

                                        None, 'icon-plus'),

        'admin_forked_repo':           (_('[forked] repository'),

                                        None, 'icon-fork'),

        'admin_updated_repo':          (_('[updated] repository'),

                                        None, 'icon-pencil'),

        'admin_created_user':          (_('[created] user'),

                                        get_user_name, 'icon-user'),

        'admin_updated_user':          (_('[updated] user'),

                                        get_user_name, 'icon-user'),

        'admin_created_users_group':   (_('[created] user group'),

                                        get_users_group, 'icon-pencil'),

        'admin_updated_users_group':   (_('[updated] user group'),

                                        get_users_group, 'icon-pencil'),

        'user_commented_revision':     (_('[commented] on revision in repository'),

                                        get_cs_links, 'icon-comment'),

        'user_commented_pull_request': (_('[commented] on pull request for'),

                                        get_pull_request, 'icon-comment'),

        'user_closed_pull_request':    (_('[closed] pull request for'),

                                        get_pull_request, 'icon-ok'),

        'push':                        (_('[pushed] into'),

                                        get_cs_links, 'icon-move-up'),

        'push_local':                  (_('[committed via Kallithea] into repository'),

                                        get_cs_links, 'icon-pencil'),

        'push_remote':                 (_('[pulled from remote] into repository'),

                                        get_cs_links, 'icon-move-up'),

        'pull':                        (_('[pulled] from'),

                                        None, 'icon-move-down'),

        'started_following_repo':      (_('[started following] repository'),

                                        None, 'icon-heart'),

        'stopped_following_repo':      (_('[stopped following] repository'),

                                        None, 'icon-heart-empty'),

    }

    action_str = action_map.get(action, action)

    if feed:

        action = action_str[0].replace('[', '').replace(']', '')

    else:

        action = action_str[0] \

            .replace('[', '<b>') \

            .replace(']', '</b>')

    action_params_func = lambda: ""

    if callable(action_str[1]):

        action_params_func = action_str[1]

    def action_parser_icon():

        action = user_log.action

        action_params = None

        x = action.split(':')

        if len(x) > 1:

            action, action_params = x

        ico = action_map.get(action, ['', '', ''])[2]

        html = """<i class="%s"></i>""" % ico

        return literal(html)

    # returned callbacks we need to call to get

    return [lambda: literal(action), action_params_func, action_parser_icon]

#==============================================================================

# GRAVATAR URL

#==============================================================================

def gravatar_div(email_address, cls='', size=30, **div_attributes):

    """Return an html literal with a span around a gravatar if they are enabled.

    Extra keyword parameters starting with 'div_' will get the prefix removed

    and '_' changed to '-' and be used as attributes on the div. The default

    class is 'gravatar'.

    """

    from tg import tmpl_context as c

    if not c.visual.use_gravatar:

        return ''

    if 'div_class' not in div_attributes:

        div_attributes['div_class'] = "gravatar"

    attributes = []

    for k, v in sorted(div_attributes.items()):

        assert k.startswith('div_'), k

        attributes.append(' %s="%s"' % (k[4:].replace('_', '-'), escape(v)))

    return literal("""<span%s>%s</span>""" %

                   (''.join(attributes),

                    gravatar(email_address, cls=cls, size=size)))

def gravatar(email_address, cls='', size=30):

    """return html element of the gravatar

    This method will return an <img> with the resolution double the size (for

    retina screens) of the image. If the url returned from gravatar_url is

    empty then we fallback to using an icon.

    """

    from tg import tmpl_context as c

    if not c.visual.use_gravatar:

        return ''

    src = gravatar_url(email_address, size * 2)

    if src:

        # here it makes sense to use style="width: ..." (instead of, say, a

        # stylesheet) because we using this to generate a high-res (retina) size

        html = ('<i class="icon-gravatar {cls}"'

                ' style="font-size: {size}px;background-size: {size}px;background-image: url(\'{src}\')"'

                '></i>').format(cls=cls, size=size, src=src)

    else:

        # if src is empty then there was no gravatar, so we use a font icon

        html = ("""<i class="icon-user {cls}" style="font-size: {size}px;"></i>"""

            .format(cls=cls, size=size, src=src))

    return literal(html)

def gravatar_url(email_address, size=30, default=''):

    # doh, we need to re-import those to mock it later

    from kallithea.config.routing import url

    from kallithea.model.db import User

    from tg import tmpl_context as c

    if not c.visual.use_gravatar:

        return ""

    _def = 'anonymous@kallithea-scm.org'  # default gravatar

    email_address = email_address or _def

    if email_address == _def:

        return default

    parsed_url = urllib.parse.urlparse(url.current(qualified=True))

    url = (c.visual.gravatar_url or User.DEFAULT_GRAVATAR_URL) \

               .replace('{email}', email_address) \

               .replace('{md5email}', hashlib.md5(safe_bytes(email_address).lower()).hexdigest()) \

               .replace('{netloc}', parsed_url.netloc) \

               .replace('{scheme}', parsed_url.scheme) \

               .replace('{size}', str(size))

    return url

def changed_tooltip(nodes):

    """

    Generates a html string for changed nodes in changeset page.

    It limits the output to 30 entries

    :param nodes: LazyNodesGenerator

    """

    if nodes:

        pref = ': <br/> '

        suf = ''

        if len(nodes) > 30:

            suf = '<br/>' + _(' and %s more') % (len(nodes) - 30)

        return literal(pref + '<br/> '.join([x.path

                                             for x in nodes[:30]]) + suf)

    else:

        return ': ' + _('No files')

def fancy_file_stats(stats):

    """

    Displays a fancy two colored bar for number of added/deleted

    lines of code on file

    :param stats: two element list of added/deleted lines of code

    """

    from kallithea.lib.diffs import NEW_FILENODE, DEL_FILENODE, \

        MOD_FILENODE, RENAMED_FILENODE, CHMOD_FILENODE, BIN_FILENODE

    a, d = stats['added'], stats['deleted']

    width = 100

    if stats['binary']:

        # binary mode

        lbl = ''

        bin_op = 1

        if BIN_FILENODE in stats['ops']:

            lbl = 'bin+'

        if NEW_FILENODE in stats['ops']:

            lbl += _('new file')

            bin_op = NEW_FILENODE

        elif MOD_FILENODE in stats['ops']:

            lbl += _('mod')

            bin_op = MOD_FILENODE

        elif DEL_FILENODE in stats['ops']:

            lbl += _('del')

            bin_op = DEL_FILENODE

        elif RENAMED_FILENODE in stats['ops']:

            lbl += _('rename')

            bin_op = RENAMED_FILENODE

        # chmod can go with other operations

        if CHMOD_FILENODE in stats['ops']:

            _org_lbl = _('chmod')

            lbl += _org_lbl if lbl.endswith('+') else '+%s' % _org_lbl

        #import ipdb;ipdb.set_trace()

        b_d = '<div class="bin bin%s progress-bar" style="width:100%%">%s</div>' % (bin_op, lbl)

        b_a = '<div class="bin bin1" style="width:0%"></div>'

        return literal('<div style="width:%spx" class="progress">%s%s</div>' % (width, b_a, b_d))

    t = stats['added'] + stats['deleted']

    unit = float(width) / (t or 1)

    # needs > 9% of width to be visible or 0 to be hidden

    a_p = max(9, unit * a) if a > 0 else 0

    d_p = max(9, unit * d) if d > 0 else 0

    p_sum = a_p + d_p

    if p_sum > width:

        # adjust the percentage to be == 100% since we adjusted to 9

        if a_p > d_p:

            a_p = a_p - (p_sum - width)

        else:

            d_p = d_p - (p_sum - width)

    a_v = a if a > 0 else ''

    d_v = d if d > 0 else ''

    d_a = '<div class="added progress-bar" style="width:%s%%">%s</div>' % (

        a_p, a_v

    )

    d_d = '<div class="deleted progress-bar" style="width:%s%%">%s</div>' % (

        d_p, d_v

    )

    return literal('<div class="progress" style="width:%spx">%s%s</div>' % (width, d_a, d_d))

_URLIFY_RE = re.compile(r'''

# URL markup

(?P<url>%s) |

# @mention markup

(?P<mention>%s) |

# Changeset hash markup

(?<!\w|[-_])

  (?P<hash>[0-9a-f]{12,40})

(?!\w|[-_]) |

# Markup of *bold text*

(?:

  (?:^|(?<=\s))

  (?P<bold> [*] (?!\s) [^*\n]* (?<!\s) [*] )

  (?![*\w])

) |

# "Stylize" markup

\[see\ \=&gt;\ *(?P<seen>[a-zA-Z0-9\/\=\?\&\ \:\/\.\-]*)\] |

\[license\ \=&gt;\ *(?P<license>[a-zA-Z0-9\/\=\?\&\ \:\/\.\-]*)\] |

\[(?P<tagtype>requires|recommends|conflicts|base)\ \=&gt;\ *(?P<tagvalue>[a-zA-Z0-9\-\/]*)\] |

\[(?:lang|language)\ \=&gt;\ *(?P<lang>[a-zA-Z\-\/\#\+]*)\] |

\[(?P<tag>[a-z]+)\]

''' % (url_re.pattern, MENTIONS_REGEX.pattern),

    re.VERBOSE | re.MULTILINE | re.IGNORECASE)

def urlify_text(s, repo_name=None, link_=None, truncate=None, stylize=False, truncatef=truncate):

    """

    Parses given text message and make literal html with markup.

    The text will be truncated to the specified length.

    Hashes are turned into changeset links to specified repository.

    URLs links to what they say.

    Issues are linked to given issue-server.

    If link_ is provided, all text not already linking somewhere will link there.

    """

    def _replace(match_obj):

        url = match_obj.group('url')

        if url is not None:

            return '<a href="%(url)s">%(url)s</a>' % {'url': url}

        mention = match_obj.group('mention')

        if mention is not None:

            return '<b>%s</b>' % mention

        hash_ = match_obj.group('hash')

        if hash_ is not None and repo_name is not None:

            from kallithea.config.routing import url  # doh, we need to re-import url to mock it later

            return '<a class="changeset_hash" href="%(url)s">%(hash)s</a>' % {

                 'url': url('changeset_home', repo_name=repo_name, revision=hash_),

                 'hash': hash_,

                }

        bold = match_obj.group('bold')

        if bold is not None:

            return '<b>*%s*</b>' % _urlify(bold[1:-1])

        if stylize:

            seen = match_obj.group('seen')

            if seen:

                return '<div class="label label-meta" data-tag="see">see =&gt; %s</div>' % seen

            license = match_obj.group('license')

            if license:

                return '<div class="label label-meta" data-tag="license"><a href="http://www.opensource.org/licenses/%s">%s</a></div>' % (license, license)

            tagtype = match_obj.group('tagtype')

            if tagtype:

                tagvalue = match_obj.group('tagvalue')

                return '<div class="label label-meta" data-tag="%s">%s =&gt; <a href="/%s">%s</a></div>' % (tagtype, tagtype, tagvalue, tagvalue)

            lang = match_obj.group('lang')

            if lang:

                return '<div class="label label-meta" data-tag="lang">%s</div>' % lang

            tag = match_obj.group('tag')

            if tag:

                return '<div class="label label-meta" data-tag="%s">%s</div>' % (tag, tag)

        return match_obj.group(0)

    def _urlify(s):

        """

        Extract urls from text and make html links out of them

        """

        return _URLIFY_RE.sub(_replace, s)

    if truncate is None:

        s = s.rstrip()

    else:

        s = truncatef(s, truncate, whole_word=True)

    s = html_escape(s)

    s = _urlify(s)

    if repo_name is not None:

        s = urlify_issues(s, repo_name)

    if link_ is not None:

        # make href around everything that isn't a href already

        s = linkify_others(s, link_)

    s = s.replace('\r\n', '<br/>').replace('\n', '<br/>')

    # Turn HTML5 into more valid HTML4 as required by some mail readers.

    # (This is not done in one step in html_escape, because character codes like

    # { risk to be seen as an issue reference due to the presence of '#'.)

    s = s.replace("'", "'")

    return literal(s)

def linkify_others(t, l):

    """Add a default link to html with links.

    HTML doesn't allow nesting of links, so the outer link must be broken up

    in pieces and give space for other links.

    """

    urls = re.compile(r'(\<a.*?\<\/a\>)',)

    links = []

    for e in urls.split(t):

        if e.strip() and not urls.match(e):

            links.append('<a class="message-link" href="%s">%s</a>' % (l, e))

        else:

            links.append(e)

    return ''.join(links)

# Global variable that will hold the actual urlify_issues function body.

# Will be set on first use when the global configuration has been read.

_urlify_issues_f = None

def urlify_issues(newtext, repo_name):

    """Urlify issue references according to .ini configuration"""

    global _urlify_issues_f

    if _urlify_issues_f is None:

        from kallithea import CONFIG

        from kallithea.model.db import URL_SEP

        assert CONFIG['sqlalchemy.url'] # make sure config has been loaded

        # Build chain of urlify functions, starting with not doing any transformation

        tmp_urlify_issues_f = lambda s: s

        issue_pat_re = re.compile(r'issue_pat(.*)')

        for k in CONFIG:

            # Find all issue_pat* settings that also have corresponding server_link and prefix configuration

            m = issue_pat_re.match(k)

            if m is None:

                continue

            suffix = m.group(1)

            issue_pat = CONFIG.get(k)

            issue_server_link = CONFIG.get('issue_server_link%s' % suffix)

            issue_sub = CONFIG.get('issue_sub%s' % suffix)

            if not issue_pat or not issue_server_link or issue_sub is None: # issue_sub can be empty but should be present

                log.error('skipping incomplete issue pattern %r: %r -> %r %r', suffix, issue_pat, issue_server_link, issue_sub)

                continue

            # Wrap tmp_urlify_issues_f with substitution of this pattern, while making sure all loop variables (and compiled regexpes) are bound

            try:

                issue_re = re.compile(issue_pat)

            except re.error as e:

                log.error('skipping invalid issue pattern %r: %r -> %r %r. Error: %s', suffix, issue_pat, issue_server_link, issue_sub, str(e))

                continue

            log.debug('issue pattern %r: %r -> %r %r', suffix, issue_pat, issue_server_link, issue_sub)

            def issues_replace(match_obj,

                               issue_server_link=issue_server_link, issue_sub=issue_sub):

                try:

                    issue_url = match_obj.expand(issue_server_link)

                except (IndexError, re.error) as e:

                    log.error('invalid issue_url setting %r -> %r %r. Error: %s', issue_pat, issue_server_link, issue_sub, str(e))

                    issue_url = issue_server_link

                issue_url = issue_url.replace('{repo}', repo_name)

                issue_url = issue_url.replace('{repo_name}', repo_name.split(URL_SEP)[-1])

                # if issue_sub is empty use the matched issue reference verbatim

                if not issue_sub:

                    issue_text = match_obj.group()

                else:

                    try:

                        issue_text = match_obj.expand(issue_sub)

                    except (IndexError, re.error) as e:

                        log.error('invalid issue_sub setting %r -> %r %r. Error: %s', issue_pat, issue_server_link, issue_sub, str(e))

                        issue_text = match_obj.group()

                return (

                    '<a class="issue-tracker-link" href="%(url)s">'

                    '%(text)s'

                    '</a>'

                    ) % {

                     'url': issue_url,

                     'text': issue_text,

                    }

            tmp_urlify_issues_f = (lambda s,

                                          issue_re=issue_re, issues_replace=issues_replace, chain_f=tmp_urlify_issues_f:

                                   issue_re.sub(issues_replace, chain_f(s)))

        # Set tmp function globally - atomically

        _urlify_issues_f = tmp_urlify_issues_f

    return _urlify_issues_f(newtext)

def render_w_mentions(source, repo_name=None):

    """

    Render plain text with revision hashes and issue references urlified

    and with @mention highlighting.

    """

    s = safe_str(source)

    s = urlify_text(s, repo_name=repo_name)

    return literal('<div class="formatted-fixed">%s</div>' % s)

def short_ref(ref_type, ref_name):

    if ref_type == 'rev':

        return short_id(ref_name)

    return ref_name

def link_to_ref(repo_name, ref_type, ref_name, rev=None):

    """

    Return full markup for a href to changeset_home for a changeset.

    If ref_type is branch it will link to changelog.

    ref_name is shortened if ref_type is 'rev'.

    if rev is specified show it too, explicitly linking to that revision.

    """

    txt = short_ref(ref_type, ref_name)

    if ref_type == 'branch':

        u = url('changelog_home', repo_name=repo_name, branch=ref_name)

    else:

        u = url('changeset_home', repo_name=repo_name, revision=ref_name)

    l = link_to(repo_name + '#' + txt, u)

    if rev and ref_type != 'rev':

        l = literal('%s (%s)' % (l, link_to(short_id(rev), url('changeset_home', repo_name=repo_name, revision=rev))))

    return l

def changeset_status(repo, revision):

    from kallithea.model.changeset_status import ChangesetStatusModel

    return ChangesetStatusModel().get_status(repo, revision)

def changeset_status_lbl(changeset_status):

    from kallithea.model.db import ChangesetStatus

    return ChangesetStatus.get_status_lbl(changeset_status)

def get_permission_name(key):

    from kallithea.model.db import Permission

    return dict(Permission.PERMS).get(key)

def journal_filter_help():

    return _(textwrap.dedent('''

        Example filter terms:

            repository:vcs

            username:developer

            action:*push*

            ip:127.0.0.1

            date:20120101

            date:[20120101100000 TO 20120102]

        Generate wildcards using '*' character:

            "repository:vcs*" - search everything starting with 'vcs'

            "repository:*vcs*" - search for repository containing 'vcs'

        Optional AND / OR operators in queries

            "repository:vcs OR repository:test"

            "username:test AND repository:test*"

    '''))

def not_mapped_error(repo_name):

    flash(_('%s repository is not mapped to db perhaps'

            ' it was created or renamed from the filesystem'

            ' please run the application again'

            ' in order to rescan repositories') % repo_name, category='error')

def ip_range(ip_addr):

    from kallithea.model.db import UserIpMap

    s, e = UserIpMap._get_ip_range(ip_addr)

    return '%s - %s' % (s, e)

session_csrf_secret_name = "_session_csrf_secret_token"

def session_csrf_secret_token():

    """Return (and create) the current session's CSRF protection token."""

    from tg import session

    if not session_csrf_secret_name in session:

        session[session_csrf_secret_name] = str(random.getrandbits(128))

        session.save()

    return session[session_csrf_secret_name]

def form(url, method="post", **attrs):

    """Like webhelpers.html.tags.form , but automatically adding

    session_csrf_secret_token for POST. The secret is thus never leaked in GET

    URLs.

    """

    form = insecure_form(url, method, **attrs)

    if method.lower() == 'get':

        return form

    return form + HTML.div(hidden(session_csrf_secret_name, session_csrf_secret_token()), style="display: none;")

# -*- coding: utf-8 -*-

# This program is free software: you can redistribute it and/or modify

# it under the terms of the GNU General Public License as published by

# the Free Software Foundation, either version 3 of the License, or

# (at your option) any later version.

#

# This program is distributed in the hope that it will be useful,

# but WITHOUT ANY WARRANTY; without even the implied warranty of

# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

# GNU General Public License for more details.

#

# You should have received a copy of the GNU General Public License

# along with this program.  If not, see <http://www.gnu.org/licenses/>.

"""

kallithea.lib.markup_renderer

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Renderer for markup languages with ability to parse using rst or markdown

This file was forked by the Kallithea project in July 2014.

Original author and date, and relevant copyright and licensing information is below:

:created_on: Oct 27, 2011

:author: marcink

:copyright: (c) 2013 RhodeCode GmbH, and others.

:license: GPLv3, see LICENSE.md for more details.

"""

import logging

import re

import traceback

import bleach

import markdown as markdown_mod

from kallithea.lib.utils2 import MENTIONS_REGEX, safe_str

log = logging.getLogger(__name__)

url_re = re.compile(r'''\bhttps?://(?:[\da-zA-Z0-9@:.-]+)'''

                    r'''(?:[/a-zA-Z0-9_=@#~&+%.,:;?!*()-]*[/a-zA-Z0-9_=@#~])?''')

class MarkupRenderer(object):

    RESTRUCTUREDTEXT_DISALLOWED_DIRECTIVES = ['include', 'meta', 'raw']

    MARKDOWN_PAT = re.compile(r'md|mkdn?|mdown|markdown', re.IGNORECASE)

    RST_PAT = re.compile(r're?st', re.IGNORECASE)

    PLAIN_PAT = re.compile(r'readme', re.IGNORECASE)

    @classmethod

    def _detect_renderer(cls, source, filename):

        """

        runs detection of what renderer should be used for generating html

        from a markup language

        filename can be also explicitly a renderer name

        """

        if cls.MARKDOWN_PAT.findall(filename):

            return cls.markdown

        elif cls.RST_PAT.findall(filename):

            return cls.rst

        elif cls.PLAIN_PAT.findall(filename):

            return cls.rst

        return cls.plain

    @classmethod

    def _flavored_markdown(cls, text):

        """

        Github style flavored markdown

        :param text:

        """

        from hashlib import md5

        # Extract pre blocks.

        extractions = {}

        def pre_extraction_callback(matchobj):

            digest = md5(matchobj.group(0)).hexdigest()

            extractions[digest] = matchobj.group(0)

            return "{gfm-extraction-%s}" % digest

        pattern = re.compile(r'<pre>.*?</pre>', re.MULTILINE | re.DOTALL)

        text = re.sub(pattern, pre_extraction_callback, text)

        # Prevent foo_bar_baz from ending up with an italic word in the middle.

        def italic_callback(matchobj):

            s = matchobj.group(0)

            if list(s).count('_') >= 2:

                return s.replace('_', r'\_')

            return s

        text = re.sub(r'^(?! {4}|\t)\w+_\w+_\w[\w_]*', italic_callback, text)

        # In very clear cases, let newlines become <br /> tags.

        def newline_callback(matchobj):

            if len(matchobj.group(1)) == 1:

                return matchobj.group(0).rstrip() + '  \n'

            else:

                return matchobj.group(0)

        pattern = re.compile(r'^[\w\<][^\n]*(\n+)', re.MULTILINE)

        text = re.sub(pattern, newline_callback, text)

        # Insert pre block extractions.

        def pre_insert_callback(matchobj):

            return '\n\n' + extractions[matchobj.group(1)]

        text = re.sub(r'{gfm-extraction-([0-9a-f]{32})\}',

                      pre_insert_callback, text)

        return text

    @classmethod

    def render(cls, source, filename=None):

        """

        Renders a given filename using detected renderer

        it detects renderers based on file extension or mimetype.

        At last it will just do a simple html replacing new lines with <br/>

        >>> MarkupRenderer.render('''<img id="a" style="margin-top:-1000px;color:red" src="http://example.com/test.jpg">''', '.md')

        '<p><img id="a" src="http://example.com/test.jpg" style="color: red;"></p>'

        >>> MarkupRenderer.render('''<img class="c d" src="file://localhost/test.jpg">''', 'b.mkd')

        '<p><img class="c d"></p>'

        >>> MarkupRenderer.render('''<a href="foo">foo</a>''', 'c.mkdn')

        '<p><a href="foo">foo</a></p>'

        >>> MarkupRenderer.render('''<script>alert(1)</script>''', 'd.mdown')

        '<script>alert(1)</script>'

        >>> MarkupRenderer.render('''<div onclick="alert(2)">yo</div>''', 'markdown')

        '<div>yo</div>'

        >>> MarkupRenderer.render('''<a href="javascript:alert(3)">yo</a>''', 'md')

        '<p><a>yo</a></p>'

        """

        renderer = cls._detect_renderer(source, filename)

        readme_data = renderer(source)

        # Allow most HTML, while preventing XSS issues:

        # no <script> tags, no onclick attributes, no javascript

        # "protocol", and also limit styling to prevent defacing.

        return bleach.clean(readme_data,

            tags=['a', 'abbr', 'b', 'blockquote', 'br', 'code', 'dd',

                  'div', 'dl', 'dt', 'em', 'h1', 'h2', 'h3', 'h4', 'h5',

                  'h6', 'hr', 'i', 'img', 'li', 'ol', 'p', 'pre', 'span',

                  'strong', 'sub', 'sup', 'table', 'tbody', 'td', 'th',

                  'thead', 'tr', 'ul'],

            attributes=['class', 'id', 'style', 'label', 'title', 'alt', 'href', 'src'],

            styles=['color'],

            protocols=['http', 'https', 'mailto'],

            )

    @classmethod

    def plain(cls, source, universal_newline=True):

        source = safe_str(source)

        if universal_newline:

            newline = '\n'

            source = newline.join(source.splitlines())

        def url_func(match_obj):

            url_full = match_obj.group(0)

            return '<a href="%(url)s">%(url)s</a>' % ({'url': url_full})

        source = url_re.sub(url_func, source)

        return '<br />' + source.replace("\n", '<br />')

    @classmethod

    def markdown(cls, source, safe=True, flavored=False):

        """

        Convert Markdown (possibly GitHub Flavored) to INSECURE HTML, possibly

        with "safe" fall-back to plaintext. Output from this method should be sanitized before use.

        >>> MarkupRenderer.markdown('''<img id="a" style="margin-top:-1000px;color:red" src="http://example.com/test.jpg">''')

        '<p><img id="a" style="margin-top:-1000px;color:red" src="http://example.com/test.jpg"></p>'

        >>> MarkupRenderer.markdown('''<img class="c d" src="file://localhost/test.jpg">''')

        '<p><img class="c d" src="file://localhost/test.jpg"></p>'

        >>> MarkupRenderer.markdown('''<a href="foo">foo</a>''')

        '<p><a href="foo">foo</a></p>'

        >>> MarkupRenderer.markdown('''<script>alert(1)</script>''')

        '<script>alert(1)</script>'

        >>> MarkupRenderer.markdown('''<div onclick="alert(2)">yo</div>''')

        '<div onclick="alert(2)">yo</div>'

        >>> MarkupRenderer.markdown('''<a href="javascript:alert(3)">yo</a>''')

        '<p><a href="javascript:alert(3)">yo</a></p>'

        >>> MarkupRenderer.markdown('''## Foo''')

        '<h2>Foo</h2>'

        >>> print(MarkupRenderer.markdown('''

        ...     #!/bin/bash

        ...     echo "hello"

        ... '''))

        <table class="code-highlighttable"><tr><td class="linenos"><div class="linenodiv"><pre>1

        2</pre></div></td><td class="code"><div class="code-highlight"><pre><span></span><span class="ch">#!/bin/bash</span>

        <span class="nb">echo</span> <span class="s2">&quot;hello&quot;</span>

        </pre></div>

        </td></tr></table>

        """

        source = safe_str(source)

        try:

            if flavored:

                source = cls._flavored_markdown(source)

            return markdown_mod.markdown(

                source,

                extensions=['markdown.extensions.codehilite', 'markdown.extensions.extra'],

                extension_configs={'markdown.extensions.codehilite': {'css_class': 'code-highlight'}})

        except Exception:

            log.error(traceback.format_exc())

            if safe:

                log.debug('Falling back to render in plain mode')

                return cls.plain(source)

            else:

                raise

    @classmethod

    def rst(cls, source, safe=True):

        source = safe_str(source)

        try:

            from docutils.core import publish_parts

            from docutils.parsers.rst import directives

            docutils_settings = dict([(alias, None) for alias in

                                cls.RESTRUCTUREDTEXT_DISALLOWED_DIRECTIVES])

            docutils_settings.update({'input_encoding': 'unicode',

                                      'report_level': 4})

            for k, v in docutils_settings.items():

                directives.register_directive(k, v)

            parts = publish_parts(source=source,

                                  writer_name="html4css1",

                                  settings_overrides=docutils_settings)