from rhodecode.lib.dbmigrate.migrate.versioning import api

        from rhodecode.lib.dbmigrate.migrate.exceptions import \

            DatabaseNotControlledError

        if 'sqlite' in self.dburi:

            print (

               '********************** WARNING **********************\n'

               'Make sure your version of sqlite is at least 3.7.X.  \n'

               'Earlier versions are known to fail on some migrations\n'

               '*****************************************************\n'

            )

        upgrade = ask_ok('You are about to perform database upgrade, make '

                         'sure You backed up your database before. '

                         'Continue ? [y/n]')

        if not upgrade:

            sys.exit('Nothing done')

        repository_path = jn(dn(dn(dn(os.path.realpath(__file__)))),

                             'rhodecode/lib/dbmigrate')

        db_uri = self.dburi

        try:

            curr_version = api.db_version(db_uri, repository_path)

            msg = ('Found current database under version'

                 ' control with version %s' % curr_version)

        except (RuntimeError, DatabaseNotControlledError):

            curr_version = 1

            msg = ('Current database is not under version control. Setting'

                   ' as version %s' % curr_version)

            api.version_control(db_uri, repository_path, curr_version)

        print (msg)

        if curr_version == __dbversion__:

            sys.exit('This database is already at the newest version')

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

        # UPGRADE STEPS

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

        class UpgradeSteps(object):

            """

            Those steps follow schema versions so for example schema

            for example schema with seq 002 == step_2 and so on.

            """

            def __init__(self, klass):

                self.klass = klass

            def step_0(self):

                # step 0 is the schema upgrade, and than follow proper upgrades

                print ('attempting to do database upgrade to version %s' \

                                % __dbversion__)

                api.upgrade(db_uri, repository_path, __dbversion__)

                print ('Schema upgrade completed')

            def step_1(self):

                pass

            def step_2(self):

                print ('Patching repo paths for newer version of RhodeCode')

                self.klass.fix_repo_paths()

                print ('Patching default user of RhodeCode')

                self.klass.fix_default_user()

                log.info('Changing ui settings')

                self.klass.create_ui_settings()

            def step_3(self):

                print ('Adding additional settings into RhodeCode db')

                self.klass.fix_settings()

                print ('Adding ldap defaults')

                self.klass.create_ldap_options(skip_existing=True)

            def step_4(self):

                print ('create permissions and fix groups')

                self.klass.create_permissions()

                self.klass.fixup_groups()

            def step_5(self):

                pass

            def step_6(self):

                pass

        upgrade_steps = [0] + range(curr_version + 1, __dbversion__ + 1)

        # CALL THE PROPER ORDER OF STEPS TO PERFORM FULL UPGRADE

        for step in upgrade_steps:

            print ('performing upgrade step %s' % step)

            getattr(UpgradeSteps(self), 'step_%s' % step)()

            self.sa.commit()

    def fix_repo_paths(self):

        """

        Fixes a old rhodecode version path into new one without a '*'

        """

        paths = self.sa.query(RhodeCodeUi)\

                .filter(RhodeCodeUi.ui_key == '/')\

                .scalar()

        paths.ui_value = paths.ui_value.replace('*', '')

        try:

            self.sa.add(paths)

            self.sa.commit()

        except:

            self.sa.rollback()

            raise

    def fix_default_user(self):

        """

        Fixes a old default user with some 'nicer' default values,

        used mostly for anonymous access

        """

        def_user = self.sa.query(User)\

                .filter(User.username == 'default')\

                .one()

        def_user.name = 'Anonymous'

        def_user.lastname = 'User'

        def_user.email = 'anonymous@rhodecode.org'

        try:

            self.sa.add(def_user)

            self.sa.commit()

        except:

            self.sa.rollback()

            raise

    def fix_settings(self):

        """

        Fixes rhodecode settings adds ga_code key for google analytics

        """

        hgsettings3 = RhodeCodeSetting('ga_code', '')

        try:

            self.sa.add(hgsettings3)

            self.sa.commit()

        except:

            self.sa.rollback()

            raise

    def admin_prompt(self, second=False, defaults={}):

        if not self.tests:

            import getpass

            # defaults

            username = defaults.get('username')

            password = defaults.get('password')

            email = defaults.get('email')

            def get_password():

                password = getpass.getpass('Specify admin password '

                                           '(min 6 chars):')

                confirm = getpass.getpass('Confirm password:')

                if password != confirm:

                    log.error('passwords mismatch')

                    return False

                if len(password) < 6:

                    log.error('password is to short use at least 6 characters')

                    return False

                return password

            if username is None:

                username = raw_input('Specify admin username:')

            if password is None:

                password = get_password()

                if not password:

                    #second try

                    password = get_password()

                    if not password:

                        sys.exit()

            if email is None:

                email = raw_input('Specify admin email:')

            self.create_user(username, password, email, True)

        else:

            log.info('creating admin and regular test users')

            from rhodecode.tests import TEST_USER_ADMIN_LOGIN,\

            TEST_USER_ADMIN_PASS, TEST_USER_ADMIN_EMAIL,\

            TEST_USER_REGULAR_LOGIN, TEST_USER_REGULAR_PASS,\

            TEST_USER_REGULAR_EMAIL, TEST_USER_REGULAR2_LOGIN, \

            TEST_USER_REGULAR2_PASS, TEST_USER_REGULAR2_EMAIL

            self.create_user(TEST_USER_ADMIN_LOGIN, TEST_USER_ADMIN_PASS,

                             TEST_USER_ADMIN_EMAIL, True)

            self.create_user(TEST_USER_REGULAR_LOGIN, TEST_USER_REGULAR_PASS,

                             TEST_USER_REGULAR_EMAIL, False)

            self.create_user(TEST_USER_REGULAR2_LOGIN, TEST_USER_REGULAR2_PASS,

                             TEST_USER_REGULAR2_EMAIL, False)

    def create_ui_settings(self):

        """

        Creates ui settings, fills out hooks

        and disables dotencode

        """

        #HOOKS

        hooks1_key = RhodeCodeUi.HOOK_UPDATE

        hooks1_ = self.sa.query(RhodeCodeUi)\

            .filter(RhodeCodeUi.ui_key == hooks1_key).scalar()

        hooks1 = RhodeCodeUi() if hooks1_ is None else hooks1_

        hooks1.ui_section = 'hooks'

        hooks1.ui_key = hooks1_key

        hooks1.ui_value = 'hg update >&2'

        hooks1.ui_active = False

        hooks2_key = RhodeCodeUi.HOOK_REPO_SIZE

        hooks2_ = self.sa.query(RhodeCodeUi)\

            .filter(RhodeCodeUi.ui_key == hooks2_key).scalar()

        hooks2 = RhodeCodeUi() if hooks2_ is None else hooks2_

        hooks2.ui_section = 'hooks'

        hooks2.ui_key = hooks2_key

        hooks2.ui_value = 'python:rhodecode.lib.hooks.repo_size'

        hooks3 = RhodeCodeUi()

        hooks3.ui_section = 'hooks'

        hooks3.ui_key = RhodeCodeUi.HOOK_PUSH

        hooks3.ui_value = 'python:rhodecode.lib.hooks.log_push_action'

        hooks4 = RhodeCodeUi()

        hooks4.ui_section = 'hooks'

        hooks4.ui_key = RhodeCodeUi.HOOK_PULL

        hooks4.ui_value = 'python:rhodecode.lib.hooks.log_pull_action'

        # For mercurial 1.7 set backward comapatibility with format

        dotencode_disable = RhodeCodeUi()

        dotencode_disable.ui_section = 'format'

        dotencode_disable.ui_key = 'dotencode'

        dotencode_disable.ui_value = 'false'

        # enable largefiles

        largefiles = RhodeCodeUi()

        largefiles.ui_section = 'extensions'

        largefiles.ui_key = 'largefiles'

        largefiles.ui_value = ''

        self.sa.add(hooks1)

        self.sa.add(hooks2)

        self.sa.add(hooks3)

        self.sa.add(hooks4)

        self.sa.add(largefiles)

    def create_ldap_options(self, skip_existing=False):

        """Creates ldap settings"""

        for k, v in [('ldap_active', 'false'), ('ldap_host', ''),

                    ('ldap_port', '389'), ('ldap_tls_kind', 'PLAIN'),

                    ('ldap_tls_reqcert', ''), ('ldap_dn_user', ''),

                    ('ldap_dn_pass', ''), ('ldap_base_dn', ''),

                    ('ldap_filter', ''), ('ldap_search_scope', ''),

                    ('ldap_attr_login', ''), ('ldap_attr_firstname', ''),

                    ('ldap_attr_lastname', ''), ('ldap_attr_email', '')]:

            if skip_existing and RhodeCodeSetting.get_by_name(k) != None:

                log.debug('Skipping option %s' % k)

                continue

            setting = RhodeCodeSetting(k, v)

            self.sa.add(setting)

    def fixup_groups(self):

        def_usr = User.get_by_username('default')

        for g in RepoGroup.query().all():

            g.group_name = g.get_new_name(g.name)

            self.sa.add(g)

            # get default perm

            default = UserRepoGroupToPerm.query()\

                .filter(UserRepoGroupToPerm.group == g)\

                .filter(UserRepoGroupToPerm.user == def_usr)\

                .scalar()

            if default is None:

                log.debug('missing default permission for group %s adding' % g)

                ReposGroupModel()._create_default_perms(g)

    def config_prompt(self, test_repo_path='', retries=3, defaults={}):

        _path = defaults.get('repos_location')

        if retries == 3:

            log.info('Setting up repositories config')

        if _path is not None:

            path = _path

        elif not self.tests and not test_repo_path:

            path = raw_input(

                 'Enter a valid absolute path to store repositories. '

                 'All repositories in that path will be added automatically:'

            )

        else:

            path = test_repo_path

        path_ok = True

        # check proper dir

        if not os.path.isdir(path):

            path_ok = False

            log.error('Given path %s is not a valid directory' % path)

        elif not os.path.isabs(path):

            path_ok = False

            log.error('Given path %s is not an absolute path' % path)

        # check write access

        elif not os.access(path, os.W_OK) and path_ok:

            path_ok = False

            log.error('No write permission to given path %s' % path)

        if retries == 0:

            sys.exit('max retries reached')

        if path_ok is False:

            retries -= 1

            return self.config_prompt(test_repo_path, retries)

        return path

    def create_settings(self, path):

        self.create_ui_settings()

        #HG UI OPTIONS

        web1 = RhodeCodeUi()

        web1.ui_section = 'web'

        web1.ui_key = 'push_ssl'

        web1.ui_value = 'false'

        web2 = RhodeCodeUi()

        web2.ui_section = 'web'

        web2.ui_key = 'allow_archive'

        web2.ui_value = 'gz zip bz2'

        web3 = RhodeCodeUi()

        web3.ui_section = 'web'

        web3.ui_key = 'allow_push'

        web3.ui_value = '*'

        web4 = RhodeCodeUi()

        web4.ui_section = 'web'

        web4.ui_key = 'baseurl'

        web4.ui_value = '/'

        paths = RhodeCodeUi()

        paths.ui_section = 'paths'

        paths.ui_key = '/'

        paths.ui_value = path

        hgsettings1 = RhodeCodeSetting('realm', 'RhodeCode authentication')

        hgsettings2 = RhodeCodeSetting('title', 'RhodeCode')

        hgsettings3 = RhodeCodeSetting('ga_code', '')

        self.sa.add(web1)

        self.sa.add(web2)

        self.sa.add(web3)

        self.sa.add(web4)

        self.sa.add(paths)

        self.sa.add(hgsettings1)

        self.sa.add(hgsettings2)

        self.sa.add(hgsettings3)

        self.create_ldap_options()

        log.info('created ui config')

    def create_user(self, username, password, email='', admin=False):

        log.info('creating user %s' % username)

        UserModel().create_or_update(username, password, email,

                                     firstname='RhodeCode', lastname='Admin',

                                     active=True, admin=admin)

    def create_default_user(self):

        log.info('creating default user')

        # create default user for handling default permissions.

        UserModel().create_or_update(username='default',

                              password=str(uuid.uuid1())[:8],

                              email='anonymous@rhodecode.org',

                              firstname='Anonymous', lastname='User')

    def create_permissions(self):

        # module.(access|create|change|delete)_[name]

        # module.(none|read|write|admin)

            if not Permission.get_by_key(p[0]):

                new_perm = Permission()

                new_perm.permission_name = p[0]

                self.sa.add(new_perm)

    def populate_default_permissions(self):

        log.info('creating default user permissions')

        default_user = self.sa.query(User)\

        .filter(User.username == 'default').scalar()

        reg_perm = UserToPerm()

        reg_perm.user = default_user

        reg_perm.permission = self.sa.query(Permission)\

        .filter(Permission.permission_name == 'hg.register.manual_activate')\

        .scalar()

        create_repo_perm = UserToPerm()

        create_repo_perm.user = default_user

        create_repo_perm.permission = self.sa.query(Permission)\

        .filter(Permission.permission_name == 'hg.create.repository')\

        .scalar()

        default_repo_perm = UserToPerm()

        default_repo_perm.user = default_user

        default_repo_perm.permission = self.sa.query(Permission)\

        .filter(Permission.permission_name == 'repository.read')\

        .scalar()

        self.sa.add(reg_perm)

        self.sa.add(create_repo_perm)

        self.sa.add(default_repo_perm)

"""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 random

import hashlib

import StringIO

import urllib

import math

import logging

from datetime import datetime

from pygments.formatters.html import HtmlFormatter

from pygments import highlight as code_highlight

from pylons import url, request, config

from pylons.i18n.translation import _, ungettext

from hashlib import md5

from webhelpers.html import literal, HTML, escape

from webhelpers.html.tools import *

from webhelpers.html.builder import make_tag

from webhelpers.html.tags import auto_discovery_link, checkbox, css_classes, \

    end_form, file, form, hidden, image, javascript_link, link_to, \

    link_to_if, link_to_unless, ol, required_legend, select, stylesheet_link, \

    submit, text, password, textarea, title, ul, xml_declaration, radio

from webhelpers.html.tools import auto_link, button_to, highlight, \

    js_obfuscate, mail_to, strip_links, strip_tags, tag_re

from webhelpers.number import format_byte_size, format_bit_size

from webhelpers.pylonslib import Flash as _Flash

from webhelpers.pylonslib.secure_form import secure_form

from webhelpers.text import chop_at, collapse, convert_accented_entities, \

    convert_misc_entities, lchop, plural, rchop, remove_formatting, \

    replace_whitespace, urlify, truncate, wrap_paragraphs

from webhelpers.date import time_ago_in_words

from webhelpers.paginate import Page

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

    convert_boolean_attrs, NotGiven, _make_safe_id_component

from rhodecode.lib.annotate import annotate_highlight

from rhodecode.lib.utils import repo_name_slug

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

    get_changeset_safe

from rhodecode.lib.markup_renderer import MarkupRenderer

from rhodecode.lib.vcs.exceptions import ChangesetDoesNotExistError

from rhodecode.lib.vcs.backends.base import BaseChangeset

from rhodecode.config.conf import DATE_FORMAT, DATETIME_FORMAT

from rhodecode.model.changeset_status import ChangesetStatusModel

log = logging.getLogger(__name__)

html_escape_table = {

    "&": "&",

    '"': """,

    "'": "'",

    ">": ">",

    "<": "&lt;",

}

def html_escape(text):

    """Produce entities within text."""

    return "".join(html_escape_table.get(c,c) for c in text)

def shorter(text, size=20):

    postfix = '...'

    if len(text) > size:

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

    return text

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 uniqe 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), md5(safe_str(path)).hexdigest()[:12])

def get_token():

    """Return the current authentication token, creating one if one doesn't

    already exist.

    """

    token_key = "_authentication_token"

    from pylons import session

    if not token_key in session:

        try:

            token = hashlib.sha1(str(random.getrandbits(128))).hexdigest()

        except AttributeError:  # Python < 2.4

            token = hashlib.sha1(str(random.randrange(2 ** 128))).hexdigest()

        session[token_key] = token

        if hasattr(session, 'save'):

            session.save()

    return session[token_key]

class _GetError(object):

    """Get error from form_errors, and represent it as span wrapped error

    message

    :param field_name: field to fetch errors for

    :param form_errors: form errors dict

    """

    def __call__(self, field_name, form_errors):

        tmpl = """<span class="error_msg">%s</span>"""

        if form_errors and field_name in form_errors:

            return literal(tmpl % form_errors.get(field_name))

get_error = _GetError()

class _ToolTip(object):

    def __call__(self, tooltip_title, trim_at=50):

        """

        Special function just to wrap our text into nice formatted

        autowrapped text

        :param tooltip_title:

        """

        tooltip_title = escape(tooltip_title)

        tooltip_title = tooltip_title.replace('<', '&lt;').replace('>', '&gt;')

        return tooltip_title

tooltip = _ToolTip()

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=''))]

        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])

                                         )

                                     )

                             )

        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 = '<div id="L%s">%s</div>' % (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" '

                      'style="background-color: #f0f0f0; padding-right: 10px">'

                      '<pre style="line-height: 125%">' +

                      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>'

def pygmentize(filenode, **kwargs):

    """pygmentize function using pygments

    :param filenode:

    """

    return literal(code_highlight(filenode.content,

                                  filenode.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 _ 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 = changeset.author

            date = changeset.date

            message = tooltip(changeset.message)

            tooltip_html = ("<div style='font-size:0.8em'><b>Author:</b>"

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

                            "</b> %s<br/></div>")

            tooltip_html = tooltip_html % (author, date, message)

            lnk_format = '%5s:%s' % ('r%s' % changeset.revision,

                                     short_id(changeset.raw_id))

            uri = link_to(

                    lnk_format,

                    url('changeset_home', repo_name=repo_name,

                        revision=changeset.raw_id),

                    style=get_color_string(changeset.raw_id),

                    class_='tooltip',

                    title=tooltip_html

                  )

            uri += '\n'

            return uri

        return _url_func

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

def is_following_repo(repo_name, user_id):

    from rhodecode.model.scm import ScmModel

    return ScmModel().is_following_repo(repo_name, user_id)

flash = _Flash()

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

# SCM FILTERS available via h.

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

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

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

from rhodecode.model.db import User, ChangesetStatus

age = lambda  x: _age(x)

capitalize = lambda x: x.capitalize()

email = author_email

short_id = lambda x: x[:12]

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

def fmt_date(date):

    if date:

        _fmt = _(u"%a, %d %b %Y %H:%M:%S").encode('utf8')

        return date.strftime(_fmt).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'

def email_or_none(author):

    _email = email(author)

    if _email != '':

        return _email

    # See if it contains a username we can get an email from

    user = User.get_by_username(author_name(author), case_insensitive=True,

                                cache=True)

    if user is not None:

        return user.email

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

    return None

def person(author):

    # attr to return from fetched user

    person_getter = lambda usr: usr.username

    # Valid email in the attribute passed, see if they're in the system

    _email = email(author)

    if _email != '':

        user = User.get_by_email(_email, case_insensitive=True, cache=True)

        if user is not None:

            return person_getter(user)

        return _email

    # Maybe it's a username?

    _author = author_name(author)

    user = User.get_by_username(_author, case_insensitive=True,

                                cache=True)

    if user is not None:

        return person_getter(user)