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

"""

    rhodecode.controllers.admin.repos

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

    Admin controller for RhodeCode

    :created_on: Apr 7, 2010

    :author: marcink

    :copyright: (C) 2009-2011 Marcin Kuzminski <marcin@python-works.com>

    :license: GPLv3, see COPYING for more details.

"""

# 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/>.

import logging

import traceback

import formencode

from operator import itemgetter

from formencode import htmlfill

from paste.httpexceptions import HTTPInternalServerError

from pylons import request, response, session, tmpl_context as c, url

from pylons.controllers.util import abort, redirect

from pylons.i18n.translation import _

from rhodecode.lib import helpers as h

from rhodecode.lib.auth import LoginRequired, HasPermissionAllDecorator, \

    HasPermissionAnyDecorator

from rhodecode.lib.base import BaseController, render

from rhodecode.lib.utils import invalidate_cache, action_logger, repo_name_slug

from rhodecode.lib.helpers import get_token

from rhodecode.model.db import User, Repository, UserFollowing, Group

from rhodecode.model.forms import RepoForm

from rhodecode.model.scm import ScmModel

from rhodecode.model.repo import RepoModel

log = logging.getLogger(__name__)

class ReposController(BaseController):

    """

    REST Controller styled on the Atom Publishing Protocol"""

    # To properly map this controller, ensure your config/routing.py

    # file has a resource setup:

    #     map.resource('repo', 'repos')

    @LoginRequired()

    @HasPermissionAnyDecorator('hg.admin', 'hg.create.repository')

    def __before__(self):

        c.admin_user = session.get('admin_user')

        c.admin_username = session.get('admin_username')

        super(ReposController, self).__before__()

    def __load_defaults(self):

        repo_model = RepoModel()

        c.repo_groups = [('', '')]

        parents_link = lambda k: h.literal('»'.join(

                                    map(lambda k: k.group_name,

                                        k.parents + [k])

                                    )

                                )

        c.repo_groups.extend([(x.group_id, parents_link(x)) for \

                                            x in self.sa.query(Group).all()])

        c.repo_groups = sorted(c.repo_groups,

                               key=lambda t: t[1].split('»')[0])

        c.repo_groups_choices = map(lambda k: unicode(k[0]), c.repo_groups)

        c.users_array = repo_model.get_users_js()

        c.users_groups_array = repo_model.get_users_groups_js()

    def __load_data(self, repo_name=None):

        """

        Load defaults settings for edit, and update

        :param repo_name:

        """

        self.__load_defaults()

        repo, dbrepo = ScmModel().get(repo_name, retval='repo')

        repo_model = RepoModel()

        c.repo_info = repo_model.get_by_repo_name(repo_name)

        if c.repo_info is None:

            h.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')

            return redirect(url('repos'))

        c.default_user_id = User.by_username('default').user_id

        c.in_public_journal = self.sa.query(UserFollowing)\

            .filter(UserFollowing.user_id == c.default_user_id)\

            .filter(UserFollowing.follows_repository == c.repo_info).scalar()

        if c.repo_info.stats:

            last_rev = c.repo_info.stats.stat_on_revision

        else:

            last_rev = 0

        c.stats_revision = last_rev

        c.repo_last_rev = repo.count() - 1 if repo.revisions else 0

        if last_rev == 0 or c.repo_last_rev == 0:

            c.stats_percentage = 0

        else:

            c.stats_percentage = '%.2f' % ((float((last_rev)) /

                                            c.repo_last_rev) * 100)

        defaults = c.repo_info.get_dict()

        group, repo_name = c.repo_info.groups_and_repo

        defaults['repo_name'] = repo_name

        defaults['repo_group'] = getattr(group[-1] if group else None,

                                         'group_id', None)

        #fill owner

        if c.repo_info.user:

            defaults.update({'user': c.repo_info.user.username})

        else:

            replacement_user = self.sa.query(User)\

            .filter(User.admin == True).first().username

            defaults.update({'user': replacement_user})

        #fill repository users

        for p in c.repo_info.repo_to_perm:

            defaults.update({'u_perm_%s' % p.user.username:

                             p.permission.permission_name})

        #fill repository groups

        for p in c.repo_info.users_group_to_perm:

            defaults.update({'g_perm_%s' % p.users_group.users_group_name:

                             p.permission.permission_name})

        return defaults

    @HasPermissionAllDecorator('hg.admin')

    def index(self, format='html'):

        """GET /repos: All items in the collection"""

        # url('repos')

        all_repos = [r.repo_name for r in Repository.query().all()]

        cached_repo_list = ScmModel().get_repos(all_repos)

        c.repos_list = sorted(cached_repo_list, key=itemgetter('name_sort'))

        return render('admin/repos/repos.html')

    @HasPermissionAnyDecorator('hg.admin', 'hg.create.repository')

    def create(self):

        """

        POST /repos: Create a new item"""

        # url('repos')

        repo_model = RepoModel()

        self.__load_defaults()

        form_result = {}

        try:

            form_result = RepoForm(repo_groups=c.repo_groups_choices)()\

                            .to_python(dict(request.POST))

            repo_model.create(form_result, self.rhodecode_user)

            if form_result['clone_uri']:

                h.flash(_('created repository %s from %s') \

                    % (form_result['repo_name'], form_result['clone_uri']),

                    category='success')

            else:

                h.flash(_('created repository %s') % form_result['repo_name'],

                    category='success')

            if request.POST.get('user_created'):

                action_logger(self.rhodecode_user, 'user_created_repo',

            else:

                action_logger(self.rhodecode_user, 'admin_created_repo',

        except formencode.Invalid, errors:

            c.new_repo = errors.value['repo_name']

            if request.POST.get('user_created'):

                r = render('admin/repos/repo_add_create_repository.html')

            else:

                r = render('admin/repos/repo_add.html')

            return htmlfill.render(

                r,

                defaults=errors.value,

                errors=errors.error_dict or {},

                prefix_error=False,

                encoding="UTF-8")

        except Exception:

            log.error(traceback.format_exc())

            msg = _('error occurred during creation of repository %s') \

                    % form_result.get('repo_name')

            h.flash(msg, category='error')

        if request.POST.get('user_created'):

            return redirect(url('home'))

        return redirect(url('repos'))

    @HasPermissionAllDecorator('hg.admin')

    def new(self, format='html'):

        """GET /repos/new: Form to create a new item"""

        new_repo = request.GET.get('repo', '')

        c.new_repo = repo_name_slug(new_repo)

        self.__load_defaults()

        return render('admin/repos/repo_add.html')

    @HasPermissionAllDecorator('hg.admin')

    def update(self, repo_name):

        """

        PUT /repos/repo_name: Update an existing item"""

        # Forms posted to this method should contain a hidden field:

        #    <input type="hidden" name="_method" value="PUT" />

        # Or using helpers:

        #    h.form(url('repo', repo_name=ID),

        #           method='put')

        # url('repo', repo_name=ID)

        self.__load_defaults()

        repo_model = RepoModel()

        changed_name = repo_name

        _form = RepoForm(edit=True, old_data={'repo_name': repo_name},

                         repo_groups=c.repo_groups_choices)()

        try:

            form_result = _form.to_python(dict(request.POST))

            repo_model.update(repo_name, form_result)

            invalidate_cache('get_repo_cached_%s' % repo_name)

            h.flash(_('Repository %s updated successfully' % repo_name),

                    category='success')

            changed_name = form_result['repo_name_full']

            action_logger(self.rhodecode_user, 'admin_updated_repo',

                              changed_name, '', self.sa)

        except formencode.Invalid, errors:

            defaults = self.__load_data(repo_name)

            defaults.update(errors.value)

            return htmlfill.render(

                render('admin/repos/repo_edit.html'),

                defaults=defaults,

                errors=errors.error_dict or {},

                prefix_error=False,

                encoding="UTF-8")

        except Exception:

            log.error(traceback.format_exc())

            h.flash(_('error occurred during update of repository %s') \

                    % repo_name, category='error')

        return redirect(url('edit_repo', repo_name=changed_name))

    @HasPermissionAllDecorator('hg.admin')

    def delete(self, repo_name):

        """

        DELETE /repos/repo_name: Delete an existing item"""

        # Forms posted to this method should contain a hidden field:

        #    <input type="hidden" name="_method" value="DELETE" />

        # Or using helpers:

        #    h.form(url('repo', repo_name=ID),

        #           method='delete')

        # url('repo', repo_name=ID)

        repo_model = RepoModel()

        repo = repo_model.get_by_repo_name(repo_name)

        if not repo:

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

                      ' it was moved or renamed  from the filesystem'

                      ' please run the application again'

                      ' in order to rescan repositories') % repo_name,

                      category='error')

            return redirect(url('repos'))

        try:

            action_logger(self.rhodecode_user, 'admin_deleted_repo',

                              repo_name, '', self.sa)

            repo_model.delete(repo)

            invalidate_cache('get_repo_cached_%s' % repo_name)

            h.flash(_('deleted repository %s') % repo_name, category='success')

        except Exception, e:

            log.error(traceback.format_exc())

            h.flash(_('An error occurred during deletion of %s') % repo_name,

                    category='error')

        return redirect(url('repos'))

    @HasPermissionAllDecorator('hg.admin')

    def delete_perm_user(self, repo_name):

        """

        DELETE an existing repository permission user

        :param repo_name:

        """

        try:

            repo_model = RepoModel()

            repo_model.delete_perm_user(request.POST, repo_name)

        except Exception, e:

            h.flash(_('An error occurred during deletion of repository user'),

                    category='error')

            raise HTTPInternalServerError()

    @HasPermissionAllDecorator('hg.admin')

    def delete_perm_users_group(self, repo_name):

        """

        DELETE an existing repository permission users group

        :param repo_name:

        """

        try:

            repo_model = RepoModel()

            repo_model.delete_perm_users_group(request.POST, repo_name)

        except Exception, e:

            h.flash(_('An error occurred during deletion of repository'

                      ' users groups'),

                    category='error')

            raise HTTPInternalServerError()

    @HasPermissionAllDecorator('hg.admin')

    def repo_stats(self, repo_name):

        """

        DELETE an existing repository statistics

        :param repo_name:

        """

        try:

            repo_model = RepoModel()

            repo_model.delete_stats(repo_name)

        except Exception, e:

            h.flash(_('An error occurred during deletion of repository stats'),

                    category='error')

        return redirect(url('edit_repo', repo_name=repo_name))

    @HasPermissionAllDecorator('hg.admin')

    def repo_cache(self, repo_name):

        """

        INVALIDATE existing repository cache

        :param repo_name:

        """

        try:

            ScmModel().mark_for_invalidation(repo_name)

        except Exception, e:

            h.flash(_('An error occurred during cache invalidation'),

                    category='error')

        return redirect(url('edit_repo', repo_name=repo_name))

    @HasPermissionAllDecorator('hg.admin')

    def repo_public_journal(self, repo_name):

        """

        Set's this repository to be visible in public journal,

        in other words assing default user to follow this repo

        :param repo_name:

        """

        cur_token = request.POST.get('auth_token')

        token = get_token()

        if cur_token == token:

            try:

                repo_id = Repository.by_repo_name(repo_name).repo_id

                user_id = User.by_username('default').user_id

                self.scm_model.toggle_following_repo(repo_id, user_id)

                h.flash(_('Updated repository visibility in public journal'),

                        category='success')

            except:

                h.flash(_('An error occurred during setting this'

                          ' repository in public journal'),

                        category='error')

        else:

            h.flash(_('Token mismatch'), category='error')

        return redirect(url('edit_repo', repo_name=repo_name))

    @HasPermissionAllDecorator('hg.admin')

    def repo_pull(self, repo_name):

        """

        Runs task to update given repository with remote changes,

        ie. make pull on remote location

        :param repo_name:

        """

        try:

            ScmModel().pull_changes(repo_name, self.rhodecode_user.username)

            h.flash(_('Pulled from remote location'), category='success')

        except Exception, e:

            h.flash(_('An error occurred during pull from remote location'),

                    category='error')

        return redirect(url('edit_repo', repo_name=repo_name))

    @HasPermissionAllDecorator('hg.admin')

    def show(self, repo_name, format='html'):

        """GET /repos/repo_name: Show a specific item"""

        # url('repo', repo_name=ID)

    @HasPermissionAllDecorator('hg.admin')

    def edit(self, repo_name, format='html'):

        """GET /repos/repo_name/edit: Form to edit an existing item"""

        # url('edit_repo', repo_name=ID)

        defaults = self.__load_data(repo_name)

        return htmlfill.render(

            render('admin/repos/repo_edit.html'),

            defaults=defaults,

            encoding="UTF-8",

            force_defaults=False

        )

def check_repo(repo_name, base_path, verify=True):

    repo_path = os.path.join(base_path, repo_name)

    try:

        if not check_repo_fast(repo_name, base_path):

            return False

        r = hg.repository(ui.ui(), repo_path)

        if verify:

            hg.verify(r)

        #here we hnow that repo exists it was verified

        log.info('%s repo is already created', repo_name)

        return False

    except RepoError:

        #it means that there is no valid repo there...

        log.info('%s repo is free for creation', repo_name)

        return True

def ask_ok(prompt, retries=4, complaint='Yes or no, please!'):

    while True:

        ok = raw_input(prompt)

        if ok in ('y', 'ye', 'yes'):

            return True

        if ok in ('n', 'no', 'nop', 'nope'):

            return False

        retries = retries - 1

        if retries < 0:

            raise IOError

        print complaint

#propagated from mercurial documentation

ui_sections = ['alias', 'auth',

                'decode/encode', 'defaults',

                'diff', 'email',

                'extensions', 'format',

                'merge-patterns', 'merge-tools',

                'hooks', 'http_proxy',

                'smtp', 'patch',

                'paths', 'profiling',

                'server', 'trusted',

                'ui', 'web', ]

def make_ui(read_from='file', path=None, checkpaths=True):

    """A function that will read python rc files or database

    and make an mercurial ui object from read options

    :param path: path to mercurial config file

    :param checkpaths: check the path

    :param read_from: read from 'file' or 'db'

    """

    baseui = ui.ui()

    #clean the baseui object

    baseui._ocfg = config.config()

    baseui._ucfg = config.config()

    baseui._tcfg = config.config()

    if read_from == 'file':

        if not os.path.isfile(path):

            log.warning('Unable to read config file %s' % path)

            return False

        log.debug('reading hgrc from %s', path)

        cfg = config.config()

        cfg.read(path)

        for section in ui_sections:

            for k, v in cfg.items(section):

                log.debug('settings ui from file[%s]%s:%s', section, k, v)

                baseui.setconfig(section, k, v)

    elif read_from == 'db':

        sa = meta.Session()

        ret = sa.query(RhodeCodeUi)\

            .options(FromCache("sql_cache_short",

                               "get_hg_ui_settings")).all()

        hg_ui = ret

        for ui_ in hg_ui:

            if ui_.ui_active:

                log.debug('settings ui from db[%s]%s:%s', ui_.ui_section,

                          ui_.ui_key, ui_.ui_value)

                baseui.setconfig(ui_.ui_section, ui_.ui_key, ui_.ui_value)

        meta.Session.remove()

    return baseui

def set_rhodecode_config(config):

    """Updates pylons config with new settings from database

    :param config:

    """

    hgsettings = RhodeCodeSettings.get_app_settings()

    for k, v in hgsettings.items():

        config[k] = v

def invalidate_cache(cache_key, *args):

    """Puts cache invalidation task into db for

    further global cache invalidation

    """

    from rhodecode.model.scm import ScmModel

    if cache_key.startswith('get_repo_cached_'):

        name = cache_key.split('get_repo_cached_')[-1]

        ScmModel().mark_for_invalidation(name)

class EmptyChangeset(BaseChangeset):

    """

    An dummy empty changeset. It's possible to pass hash when creating

    an EmptyChangeset

    """

    def __init__(self, cs='0' * 40, repo=None):

        self._empty_cs = cs

        self.revision = -1

        self.message = ''

        self.author = ''

        self.date = ''

        self.repository = repo

    @LazyProperty

    def raw_id(self):

        """Returns raw string identifying this changeset, useful for web

        representation.

        """

        return self._empty_cs

    @LazyProperty

    def short_id(self):

        return self.raw_id[:12]

    def get_file_changeset(self, path):

        return self

    def get_file_content(self, path):

        return u''

    def get_file_size(self, path):

        return 0

def map_groups(groups):

    """Checks for groups existence, and creates groups structures.

    It returns last group in structure

    :param groups: list of groups structure

    """

    sa = meta.Session()

    parent = None

    group = None

    for lvl, group_name in enumerate(groups[:-1]):

        group = sa.query(Group).filter(Group.group_name == group_name).scalar()

        if group is None:

            group = Group(group_name, parent)

            sa.add(group)

            sa.commit()

        parent = group

    return group

def repo2db_mapper(initial_repo_list, remove_obsolete=False):

    """maps all repos given in initial_repo_list, non existing repositories

    are created, if remove_obsolete is True it also check for db entries

    that are not in initial_repo_list and removes them.

    :param initial_repo_list: list of repositories found by scanning methods

    :param remove_obsolete: check for obsolete entries in database

    """

    sa = meta.Session()

    rm = RepoModel()

    user = sa.query(User).filter(User.admin == True).first()

    added = []

    for name, repo in initial_repo_list.items():

        group = map_groups(name.split('/'))

        if not rm.get_by_repo_name(name, cache=False):

            log.info('repository %s not found creating default', name)

            added.append(name)

            form_data = {

                         'repo_name': name,

                         'repo_type': repo.alias,

                         'description': repo.description \

                            if repo.description != 'unknown' else \

                                        '%s repository' % name,

                         'private': False,

                         'group_id': getattr(group, 'group_id', None)

                         }

            rm.create(form_data, user, just_db=True)

    removed = []

    if remove_obsolete:

        #remove from database those repositories that are not in the filesystem

        for repo in sa.query(Repository).all():

            if repo.repo_name not in initial_repo_list.keys():

                removed.append(repo.repo_name)

                sa.delete(repo)

                sa.commit()

    return added, removed

#set cache regions for beaker so celery can utilise it

def add_cache(settings):

    cache_settings = {'regions': None}

    for key in settings.keys():

        for prefix in ['beaker.cache.', 'cache.']:

            if key.startswith(prefix):

                name = key.split(prefix)[1].strip()

                cache_settings[name] = settings[key].strip()

    if cache_settings['regions']:

        for region in cache_settings['regions'].split(','):

            region = region.strip()

            region_settings = {}

            for key, value in cache_settings.items():

                if key.startswith(region):

                    region_settings[key.split('.')[1]] = value

            region_settings['expire'] = int(region_settings.get('expire',

                                                                60))

            region_settings.setdefault('lock_dir',

                                       cache_settings.get('lock_dir'))

            region_settings.setdefault('data_dir',

                                       cache_settings.get('data_dir'))

            if 'type' not in region_settings:

                region_settings['type'] = cache_settings.get('type',

                                                             'memory')

            beaker.cache.cache_regions[region] = region_settings

def get_current_revision():

    """Returns tuple of (number, id) from repository containing this package

    or None if repository could not be found.

    """

    try:

        from vcs import get_repo

        from vcs.utils.helpers import get_scm

        from vcs.exceptions import RepositoryError, VCSError

        repopath = os.path.join(os.path.dirname(__file__), '..', '..')

        scm = get_scm(repopath)[0]

        repo = get_repo(path=repopath, alias=scm)

        tip = repo.get_changeset()

        return (tip.revision, tip.short_id)

    except (ImportError, RepositoryError, VCSError), err:

        logging.debug("Cannot retrieve rhodecode's revision. Original error "

                      "was: %s" % err)

        return None

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

# TEST FUNCTIONS AND CREATORS

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

def create_test_index(repo_location, full_index):

    """Makes default test index

    :param repo_location:

    :param full_index:

    """

    from rhodecode.lib.indexers.daemon import WhooshIndexingDaemon

    from rhodecode.lib.pidlock import DaemonLock, LockHeld

    import shutil

    index_location = os.path.join(repo_location, 'index')

    if os.path.exists(index_location):

        shutil.rmtree(index_location)

    try:

        l = DaemonLock(file=jn(dn(dn(index_location)), 'make_index.lock'))

        WhooshIndexingDaemon(index_location=index_location,

                             repo_location=repo_location)\

            .run(full_index=full_index)

        l.release()

    except LockHeld:

        pass

def create_test_env(repos_test_path, config):

    """Makes a fresh database and

    install test repository into tmp dir

    """

    from rhodecode.lib.db_manage import DbManage

    from rhodecode.tests import HG_REPO, GIT_REPO, NEW_HG_REPO, NEW_GIT_REPO, \

        HG_FORK, GIT_FORK, TESTS_TMP_PATH

    import tarfile

    import shutil

    from os.path import dirname as dn, join as jn, abspath

    log = logging.getLogger('TestEnvCreator')

    # create logger

    log.setLevel(logging.DEBUG)

    log.propagate = True

    # create console handler and set level to debug

    ch = logging.StreamHandler()

    ch.setLevel(logging.DEBUG)

    # create formatter

    formatter = logging.Formatter("%(asctime)s - %(name)s -"

                                  " %(levelname)s - %(message)s")

    # add formatter to ch

    ch.setFormatter(formatter)

    # add ch to logger

    log.addHandler(ch)

    #PART ONE create db

    dbconf = config['sqlalchemy.db1.url']

    log.debug('making test db %s', dbconf)

    dbmanage = DbManage(log_sql=True, dbconf=dbconf, root=config['here'],

                        tests=True)

    dbmanage.create_tables(override=True)

    dbmanage.create_settings(dbmanage.config_prompt(repos_test_path))

    dbmanage.create_default_user()

    dbmanage.admin_prompt()

    dbmanage.create_permissions()

    dbmanage.populate_default_permissions()

    #PART TWO make test repo

    log.debug('making test vcs repositories')

    #remove old one from previos tests

    for r in [HG_REPO, GIT_REPO, NEW_HG_REPO, NEW_GIT_REPO, HG_FORK, GIT_FORK]:

        if os.path.isdir(jn(TESTS_TMP_PATH, r)):

            log.debug('removing %s', r)

            shutil.rmtree(jn(TESTS_TMP_PATH, r))

    #CREATE DEFAULT HG REPOSITORY

    cur_dir = dn(dn(abspath(__file__)))

    tar = tarfile.open(jn(cur_dir, 'tests', "vcs_test_hg.tar.gz"))

    tar.extractall(jn(TESTS_TMP_PATH, HG_REPO))

    tar.close()

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

# PASTER COMMANDS

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

class BasePasterCommand(Command):

    """

    Abstract Base Class for paster commands.

    The celery commands are somewhat aggressive about loading

    celery.conf, and since our module sets the `CELERY_LOADER`

    environment variable to our loader, we have to bootstrap a bit and

    make sure we've had a chance to load the pylons config off of the

    command line, otherwise everything fails.

    """

    min_args = 1

    min_args_error = "Please provide a paster config file as an argument."

    takes_config_file = 1

    requires_config_file = True

    def notify_msg(self, msg, log=False):

        """Make a notification to user, additionally if logger is passed

        it logs this action using given logger

        :param msg: message that will be printed to user

        :param log: logging instance, to use to additionally log this message

        """

        if log and isinstance(log, logging):

            log(msg)

    def run(self, args):

        """

        Overrides Command.run

        Checks for a config file argument and loads it.

        """

        if len(args) < self.min_args:

            raise BadCommand(

                self.min_args_error % {'min_args': self.min_args,

                                       'actual_args': len(args)})

from rhodecode.model.user import UserModel

from rhodecode.model.repo import RepoModel

from rhodecode.model.db import User, UsersGroup, Group

from rhodecode import BACKENDS

log = logging.getLogger(__name__)

#this is needed to translate the messages using _() in validators

class State_obj(object):

    _ = staticmethod(_)

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

# VALIDATORS

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

class ValidAuthToken(formencode.validators.FancyValidator):

    messages = {'invalid_token':_('Token mismatch')}

    def validate_python(self, value, state):

        if value != authentication_token():

            raise formencode.Invalid(self.message('invalid_token', state,

                                            search_number=value), value, state)

def ValidUsername(edit, old_data):

    class _ValidUsername(formencode.validators.FancyValidator):

        def validate_python(self, value, state):

            if value in ['default', 'new_user']:

                raise formencode.Invalid(_('Invalid username'), value, state)

            #check if user is unique

            old_un = None

            if edit:

                old_un = UserModel().get(old_data.get('user_id')).username

            if old_un != value or not edit:

                if UserModel().get_by_username(value, cache=False,

                                               case_insensitive=True):

                    raise formencode.Invalid(_('This username already '

                                               'exists') , value, state)

            if re.match(r'^[a-zA-Z0-9]{1}[a-zA-Z0-9\-\_\.]+$', value) is None:

                raise formencode.Invalid(_('Username may only contain '

                                           'alphanumeric characters '

                                           'underscores, periods or dashes '

                                           'and must begin with alphanumeric '

                                           'character'), value, state)