# -*- 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/>.

"""

Helper functions

Consists of functions to typically be used within templates, but also

available to Controllers. This module is available to both as 'h'.

"""

import hashlib

import json

import StringIO

import logging

import re

import urlparse

import textwrap

from beaker.cache import cache_region

from pygments.formatters.html import HtmlFormatter

from pygments import highlight as code_highlight

from tg.i18n import ugettext as _

from webhelpers.html import literal, HTML, escape

from webhelpers.html.tags import checkbox, end_form, hidden, link_to, \

    select, submit, text, password, textarea, radio, form as insecure_form

from webhelpers.number import format_byte_size

from webhelpers.pylonslib import Flash as _Flash

from webhelpers.pylonslib.secure_form import secure_form, authentication_token

from webhelpers.text import chop_at, truncate, wrap_paragraphs

from webhelpers.html.tags import _set_input_attrs, _set_id_attr, \

    convert_boolean_attrs, NotGiven, _make_safe_id_component

from kallithea.config.routing import url

from kallithea.lib.annotate import annotate_highlight

from kallithea.lib.pygmentsutils import get_custom_lexer

from kallithea.lib.utils2 import str2bool, safe_unicode, safe_str, \

    time_to_datetime, AttributeDict, safe_int, MENTIONS_REGEX

from kallithea.lib.markup_renderer import url_re

from kallithea.lib.vcs.exceptions import ChangesetDoesNotExistError

from kallithea.lib.vcs.backends.base import BaseChangeset, EmptyChangeset

log = logging.getLogger(__name__)

def canonical_url(*args, **kargs):

    '''Like url(x, qualified=True), but returns url that not only is qualified

    but also canonical, as configured in canonical_url'''

    from kallithea import CONFIG

    try:

        parts = CONFIG.get('canonical_url', '').split('://', 1)

        kargs['host'] = parts[1].split('/', 1)[0]

        kargs['protocol'] = parts[0]

    except IndexError:

        kargs['qualified'] = True

    return url(*args, **kargs)

def canonical_hostname():

    '''Return canonical hostname of system'''

    from kallithea import CONFIG

    try:

        parts = CONFIG.get('canonical_url', '').split('://', 1)

        return parts[1].split('/', 1)[0]

    except IndexError:

        parts = url('home', qualified=True).split('://', 1)

        return parts[1].split('/', 1)[0]

def html_escape(s):

    """Return string with all html escaped.

    This is also safe for javascript in html but not necessarily correct.

    """

    return (s

        .replace('&', '&')

        .replace(">", ">")

        .replace("<", "&lt;")

        .replace('"', """)

        .replace("'", "'")

        )

def js(value):

    """Convert Python value to the corresponding JavaScript representation.

    This is necessary to safely insert arbitrary values into HTML <script>

    sections e.g. using Mako template expression substitution.

    Note: Rather than using this function, it's preferable to avoid the

    insertion of values into HTML <script> sections altogether. Instead,

    data should (to the extent possible) be passed to JavaScript using

    data attributes or AJAX calls, eliminating the need for JS specific

    escaping.

    Note: This is not safe for use in attributes (e.g. onclick), because

    quotes are not escaped.

    Because the rules for parsing <script> varies between XHTML (where

    normal rules apply for any special characters) and HTML (where

    entities are not interpreted, but the literal string "</script>"

    is forbidden), the function ensures that the result never contains

    '&', '<' and '>', thus making it safe in both those contexts (but

    not in attributes).

    """

    return literal(

        ('(' + json.dumps(value) + ')')

        # In JSON, the following can only appear in string literals.

        .replace('&', r'\x26')

        .replace('<', r'\x3c')

        .replace('>', r'\x3e')

    )

def jshtml(val):

    """HTML escapes a string value, then converts the resulting string

    to its corresponding JavaScript representation (see `js`).

    This is used when a plain-text string (possibly containing special

    HTML characters) will be used by a script in an HTML context (e.g.

    element.innerHTML or jQuery's 'html' method).

    If in doubt, err on the side of using `jshtml` over `js`, since it's

    better to escape too much than too little.

    """

    return js(escape(val))

def shorter(s, size=20, firstline=False, postfix='...'):

    """Truncate s to size, including the postfix string if truncating.

    If firstline, truncate at newline.

    """

    if firstline:

        s = s.split('\n', 1)[0].rstrip()

    if len(s) > size:

        return s[:size - len(postfix)] + postfix

    return s

def _reset(name, value=None, id=NotGiven, type="reset", **attrs):

    """

    Reset button

    """

    _set_input_attrs(attrs, type, name, value)

    _set_id_attr(attrs, id, name)

    convert_boolean_attrs(attrs, ["disabled"])

    return HTML.input(**attrs)

reset = _reset

safeid = _make_safe_id_component

def FID(raw_id, path):

    """

    Creates a unique ID for filenode based on it's hash of path and revision

    it's safe to use in urls

    :param raw_id:

    :param path:

    """

    return 'C-%s-%s' % (short_id(raw_id), hashlib.md5(safe_str(path)).hexdigest()[:12])

class _FilesBreadCrumbs(object):

    def __call__(self, repo_name, rev, paths):

        if isinstance(paths, str):

            paths = safe_unicode(paths)

        url_l = [link_to(repo_name, url('files_home',

                                        repo_name=repo_name,

                                        revision=rev, f_path=''),

                         class_='ypjax-link')]

        paths_l = paths.split('/')

        for cnt, p in enumerate(paths_l):

            if p != '':

                url_l.append(link_to(p,

                                     url('files_home',

                                         repo_name=repo_name,

                                         revision=rev,

                                         f_path='/'.join(paths_l[:cnt + 1])

                                         ),

                                     class_='ypjax-link'

                                     )

                             )

        return literal('/'.join(url_l))

files_breadcrumbs = _FilesBreadCrumbs()

class CodeHtmlFormatter(HtmlFormatter):

    """

    My code Html Formatter for source codes

    """

    def wrap(self, source, outfile):

        return self._wrap_div(self._wrap_pre(self._wrap_code(source)))

    def _wrap_code(self, source):

        for cnt, it in enumerate(source):

            i, t = it

            t = '<span id="L%s">%s</span>' % (cnt + 1, t)

            yield i, t

    def _wrap_tablelinenos(self, inner):

        dummyoutfile = StringIO.StringIO()

        lncount = 0

        for t, line in inner:

            if t:

                lncount += 1

            dummyoutfile.write(line)

        fl = self.linenostart

        mw = len(str(lncount + fl - 1))

        sp = self.linenospecial

        st = self.linenostep

        la = self.lineanchors

        aln = self.anchorlinenos

        nocls = self.noclasses

        if sp:

            lines = []

            for i in range(fl, fl + lncount):

                if i % st == 0:

                    if i % sp == 0:

                        if aln:

                            lines.append('<a href="#%s%d" class="special">%*d</a>' %

                                         (la, i, mw, i))

                        else:

                            lines.append('<span class="special">%*d</span>' % (mw, i))

                    else:

                        if aln:

                            lines.append('<a href="#%s%d">%*d</a>' % (la, i, mw, i))

                        else:

                            lines.append('%*d' % (mw, i))

                else:

                    lines.append('')

            ls = '\n'.join(lines)

        else:

            lines = []

            for i in range(fl, fl + lncount):

                if i % st == 0:

                    if aln:

                        lines.append('<a href="#%s%d">%*d</a>' % (la, i, mw, i))

                    else:

                        lines.append('%*d' % (mw, i))

                else:

                    lines.append('')

            ls = '\n'.join(lines)

        # in case you wonder about the seemingly redundant <div> here: since the

        # content in the other cell also is wrapped in a div, some browsers in

        # some configurations seem to mess up the formatting...

        if nocls:

            yield 0, ('<table class="%stable">' % self.cssclass +

                      '<tr><td><div class="linenodiv">'

                      '<pre>' + ls + '</pre></div></td>'

                      '<td id="hlcode" class="code">')

        else:

            yield 0, ('<table class="%stable">' % self.cssclass +

                      '<tr><td class="linenos"><div class="linenodiv">'

                      '<pre>' + ls + '</pre></div></td>'

                      '<td id="hlcode" class="code">')

        yield 0, dummyoutfile.getvalue()

        yield 0, '</td></tr></table>'

_whitespace_re = re.compile(r'(\t)|( )(?=\n|</div>)')

def _markup_whitespace(m):

    groups = m.groups()

    if groups[0]:

        return '<u>\t</u>'

    if groups[1]:

        return ' <i></i>'

def markup_whitespace(s):

    return _whitespace_re.sub(_markup_whitespace, s)

def pygmentize(filenode, **kwargs):

    """

    pygmentize function using pygments

    :param filenode:

    """

    lexer = get_custom_lexer(filenode.extension) or filenode.lexer

    return literal(markup_whitespace(

        code_highlight(filenode.content, lexer, CodeHtmlFormatter(**kwargs))))

def pygmentize_annotation(repo_name, filenode, **kwargs):

    """

    pygmentize function for annotation

    :param filenode:

    """

    color_dict = {}

    def gen_color(n=10000):

        """generator for getting n of evenly distributed colors using

        hsv color and golden ratio. It always return same order of colors

        :returns: RGB tuple

        """

        def hsv_to_rgb(h, s, v):

            if s == 0.0:

                return v, v, v

            i = int(h * 6.0)  # XXX assume int() truncates!

            f = (h * 6.0) - i

            p = v * (1.0 - s)

            q = v * (1.0 - s * f)

            t = v * (1.0 - s * (1.0 - f))

            i = i % 6

            if i == 0:

                return v, t, p

            if i == 1:

                return q, v, p

            if i == 2:

                return p, v, t

            if i == 3:

                return p, q, v

            if i == 4:

                return t, p, v

            if i == 5:

                return v, p, q

        golden_ratio = 0.618033988749895

        h = 0.22717784590367374

        for _unused in xrange(n):

            h += golden_ratio

            h %= 1

            HSV_tuple = [h, 0.95, 0.95]

            RGB_tuple = hsv_to_rgb(*HSV_tuple)

            yield map(lambda x: str(int(x * 256)), RGB_tuple)

    cgenerator = gen_color()

    def get_color_string(cs):

        if cs in color_dict:

            col = color_dict[cs]

        else:

            col = color_dict[cs] = cgenerator.next()

        return "color: rgb(%s)! important;" % (', '.join(col))

    def url_func(repo_name):

        def _url_func(changeset):

            author = escape(changeset.author)

            date = changeset.date

            message = escape(changeset.message)

            tooltip_html = ("<b>Author:</b> %s<br/>"

                            "<b>Date:</b> %s</b><br/>"

                            "<b>Message:</b> %s") % (author, date, message)

            lnk_format = show_id(changeset)

            uri = link_to(

                    lnk_format,

                    url('changeset_home', repo_name=repo_name,

                        revision=changeset.raw_id),

                    style=get_color_string(changeset.raw_id),

                    **{'data-toggle': 'popover',

                       'data-content': tooltip_html}

                  )

            uri += '\n'

            return uri

        return _url_func

    return literal(markup_whitespace(annotate_highlight(filenode, url_func(repo_name), **kwargs)))

class _Message(object):

    """A message returned by ``Flash.pop_messages()``.

    Converting the message to a string returns the message text. Instances

    also have the following attributes:

    * ``message``: the message text.

    * ``category``: the category specified when the message was created.

    """

    def __init__(self, category, message):

        self.category = category

        self.message = message

    def __str__(self):

        return self.message

    __unicode__ = __str__

    def __html__(self):

        return escape(safe_unicode(self.message))

class Flash(_Flash):

    def __call__(self, message, category=None, ignore_duplicate=False, logf=None):

        """

        Show a message to the user _and_ log it through the specified function

        category: notice (default), warning, error, success

        logf: a custom log function - such as log.debug

        logf defaults to log.info, unless category equals 'success', in which

        case logf defaults to log.debug.

        """

        if logf is None:

            logf = log.info

            if category == 'success':

                logf = log.debug

        logf('Flash %s: %s', category, message)

        super(Flash, self).__call__(message, category, ignore_duplicate)

    def pop_messages(self):

        """Return all accumulated messages and delete them from the session.

        The return value is a list of ``Message`` objects.

        """

        from tg import session

        messages = session.pop(self.session_key, [])

        session.save()

        return [_Message(*m) for m in messages]

flash = Flash()

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

# SCM FILTERS available via h.

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

from kallithea.lib.vcs.utils import author_name, author_email

from kallithea.lib.utils2 import credentials_filter, age as _age

age = lambda  x, y=False: _age(x, y)

capitalize = lambda x: x.capitalize()

email = author_email

short_id = lambda x: x[:12]

hide_credentials = lambda x: ''.join(credentials_filter(x))

def show_id(cs):

    """

    Configurable function that shows ID

    by default it's r123:fffeeefffeee

    :param cs: changeset instance

    """

    from kallithea import CONFIG

    def_len = safe_int(CONFIG.get('show_sha_length', 12))

    show_rev = str2bool(CONFIG.get('show_revision_number', False))

    raw_id = cs.raw_id[:def_len]

    if show_rev:

        return 'r%s:%s' % (cs.revision, raw_id)

    else:

        return raw_id

def fmt_date(date):

    if date:

        return date.strftime("%Y-%m-%d %H:%M:%S").decode('utf8')

    return ""

def is_git(repository):

    if hasattr(repository, 'alias'):

        _type = repository.alias

    elif hasattr(repository, 'repo_type'):

        _type = repository.repo_type

    else:

        _type = repository

    return _type == 'git'

def is_hg(repository):

    if hasattr(repository, 'alias'):

        _type = repository.alias

    elif hasattr(repository, 'repo_type'):

        _type = repository.repo_type

    else:

        _type = repository

    return _type == 'hg'

@cache_region('long_term', 'user_or_none')

def user_or_none(author):

    """Try to match email part of VCS committer string with a local user - or return None"""

    from kallithea.model.db import User

    email = author_email(author)

    if email:

        return User.get_by_email(email, cache=True) # cache will only use sql_cache_short

    return None

def email_or_none(author):

    """Try to match email part of VCS committer string with a local user.

    Return primary email of user, email part of the specified author name, or None."""

    if not author:

        return None

    user = user_or_none(author)

    if user is not None:

        return user.email # always use main email address - not necessarily the one used to find user

    # extract email from the commit string

    email = author_email(author)

    if email:

        return email

    # No valid email, not a valid user in the system, none!

    return None

def person(author, show_attr="username"):

    """Find the user identified by 'author', return one of the users attributes,

    default to the username attribute, None if there is no user"""

    from kallithea.model.db import User

    # attr to return from fetched user

    person_getter = lambda usr: getattr(usr, show_attr)

    # if author is already an instance use it for extraction

    if isinstance(author, User):

        return person_getter(author)

    user = user_or_none(author)

    if user is not None:

        return person_getter(user)

    # Still nothing?  Just pass back the author name if any, else the email

    return author_name(author) or email(author)

def person_by_id(id_, show_attr="username"):

    from kallithea.model.db import User

    # attr to return from fetched user

    person_getter = lambda usr: getattr(usr, show_attr)

    #maybe it's an ID ?

    if str(id_).isdigit() or isinstance(id_, int):

        id_ = int(id_)

        user = User.get(id_)

        if user is not None:

            return person_getter(user)

    return id_

def boolicon(value):

    """Returns boolean value of a value, represented as small html image of true/false

    icons

    :param value: value

    """

    if value:

        return HTML.tag('i', class_="icon-ok")

    else:

        return HTML.tag('i', class_="icon-minus-circled")

def action_parser(user_log, feed=False, parse_cs=False):

    """

    This helper will action_map the specified string action into translated

    fancy names with icons and links

    :param user_log: user log instance

    :param feed: use output for feeds (no html and fancy icons)

    :param parse_cs: parse Changesets into VCS instances

    """

    action = user_log.action

    action_params = ' '

    x = action.split(':')

    if len(x) > 1:

        action, action_params = x

    def get_cs_links():

        revs_limit = 3  # display this amount always

        revs_top_limit = 50  # show upto this amount of changesets hidden

        revs_ids = action_params.split(',')

        deleted = user_log.repository is None

        if deleted:

            return ','.join(revs_ids)

        repo_name = user_log.repository.repo_name

        def lnk(rev, repo_name):

            lazy_cs = False

            title_ = None

            url_ = '#'

            if isinstance(rev, BaseChangeset) or isinstance(rev, AttributeDict):

                if rev.op and rev.ref_name:

                    if rev.op == 'delete_branch':

                        lbl = _('Deleted branch: %s') % rev.ref_name

                    elif rev.op == 'tag':

                        lbl = _('Created tag: %s') % rev.ref_name

                    else:

                        lbl = 'Unknown operation %s' % rev.op

                else:

                    lazy_cs = True

                    lbl = rev.short_id[:8]

                    url_ = url('changeset_home', repo_name=repo_name,

                               revision=rev.raw_id)

            else:

                # changeset cannot be found - it might have been stripped or removed

                lbl = rev[:12]

                title_ = _('Changeset %s not found') % lbl

            if parse_cs:

                return link_to(lbl, url_, title=title_, **{'data-toggle': 'tooltip'})

            return link_to(lbl, url_, class_='lazy-cs' if lazy_cs else '',

                           **{'data-raw_id':rev.raw_id, 'data-repo_name':repo_name})

        def _get_op(rev_txt):

            _op = None

            _name = rev_txt

            if len(rev_txt.split('=>')) == 2:

                _op, _name = rev_txt.split('=>')

            return _op, _name

        revs = []

        if len(filter(lambda v: v != '', revs_ids)) > 0:

            repo = None

            for rev in revs_ids[:revs_top_limit]:

                _op, _name = _get_op(rev)

                # we want parsed changesets, or new log store format is bad

                if parse_cs:

                    try:

                        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]

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

# PERMS

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

from kallithea.lib.auth import HasPermissionAny, \

    HasRepoPermissionLevel, HasRepoGroupPermissionLevel

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

# GRAVATAR URL

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

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

    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)))

                   (''.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 = ('<img alt="" class="{cls}" style="width: {size}px; height: {size}px" src="{src}"/>'

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

    else: