"""The base Controller API

Provides the BaseController class for subclassing.

"""

import logging

import time

import traceback

from paste.auth.basic import AuthBasicAuthenticator

from paste.httpexceptions import HTTPUnauthorized, HTTPForbidden

from paste.httpheaders import WWW_AUTHENTICATE, AUTHORIZATION

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

from pylons.controllers import WSGIController

from pylons.controllers.util import redirect

from pylons.templating import render_mako as render

from rhodecode import __version__, BACKENDS

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

    safe_str, safe_int

from rhodecode.lib.auth import AuthUser, get_container_username, authfunc,\

    HasPermissionAnyMiddleware, CookieStoreWrapper

from rhodecode.lib.utils import get_repo_slug, invalidate_cache

from rhodecode.model import meta

from rhodecode.model.db import Repository, RhodeCodeUi, User, RhodeCodeSetting

from rhodecode.model.notification import NotificationModel

from rhodecode.model.scm import ScmModel

from rhodecode.model.meta import Session

log = logging.getLogger(__name__)

def _get_ip_addr(environ):

    proxy_key = 'HTTP_X_REAL_IP'

    proxy_key2 = 'HTTP_X_FORWARDED_FOR'

    def_key = 'REMOTE_ADDR'

    ip = environ.get(proxy_key)

    if ip:

        return ip

    ip = environ.get(proxy_key2)

    if ip:

        return ip

    ip = environ.get(def_key, '0.0.0.0')

    # HEADERS can have mutliple ips inside

    # the left-most being the original client, and each successive proxy

    # that passed the request adding the IP address where it received the

    # request from.

    if ',' in ip:

        ip = ip.split(',')[0].strip()

    return ip

def _get_access_path(environ):

    path = environ.get('PATH_INFO')

    org_req = environ.get('pylons.original_request')

    if org_req:

        path = org_req.environ.get('PATH_INFO')

    return path

class BasicAuth(AuthBasicAuthenticator):

    def __init__(self, realm, authfunc, auth_http_code=None):

        self.realm = realm

        self.authfunc = authfunc

        self._rc_auth_http_code = auth_http_code

    def build_authentication(self):

        head = WWW_AUTHENTICATE.tuples('Basic realm="%s"' % self.realm)

        if self._rc_auth_http_code and self._rc_auth_http_code == '403':

            # return 403 if alternative http return code is specified in

            # RhodeCode config

            return HTTPForbidden(headers=head)

        return HTTPUnauthorized(headers=head)

    def authenticate(self, environ):

        authorization = AUTHORIZATION(environ)

        if not authorization:

            return self.build_authentication()

        (authmeth, auth) = authorization.split(' ', 1)

        if 'basic' != authmeth.lower():

            return self.build_authentication()

        auth = auth.strip().decode('base64')

        _parts = auth.split(':', 1)

        if len(_parts) == 2:

            username, password = _parts

            if self.authfunc(environ, username, password):

                return username

        return self.build_authentication()

    __call__ = authenticate

class BaseVCSController(object):

    def __init__(self, application, config):

        self.application = application

        self.config = config

        # base path of repo locations

        self.basepath = self.config['base_path']

        #authenticate this mercurial request using authfunc

        self.authenticate = BasicAuth('', authfunc,

                                      config.get('auth_ret_code'))

        self.ip_addr = '0.0.0.0'

    def _handle_request(self, environ, start_response):

        raise NotImplementedError()

    def _get_by_id(self, repo_name):

        """

        Get's a special pattern _<ID> from clone url and tries to replace it

        with a repository_name for support of _<ID> non changable urls

        :param repo_name:

        """

        try:

            data = repo_name.split('/')

            if len(data) >= 2:

                by_id = data[1].split('_')

                if len(by_id) == 2 and by_id[1].isdigit():

                    _repo_name = Repository.get(by_id[1]).repo_name

                    data[1] = _repo_name

        except:

            log.debug('Failed to extract repo_name from id %s' % (

                      traceback.format_exc()

                      )

            )

        return '/'.join(data)

    def _invalidate_cache(self, repo_name):

        """

        Set's cache for this repository for invalidation on next access

        :param repo_name: full repo name, also a cache key

        """

        invalidate_cache('get_repo_cached_%s' % repo_name)

    def _check_permission(self, action, user, repo_name, ip_addr=None):

        """

        Checks permissions using action (push/pull) user and repository

        name

        :param action: push or pull action

        :param user: user instance

        :param repo_name: repository name

        """

        #check IP

        authuser = AuthUser(user_id=user.user_id, ip_addr=ip_addr)

        if not authuser.ip_allowed:

            return False

        else:

            log.info('Access for IP:%s allowed' % (ip_addr))

        if action == 'push':

            if not HasPermissionAnyMiddleware('repository.write',

                                              'repository.admin')(user,

                                                                  repo_name):

                return False

        else:

            #any other action need at least read permission

            if not HasPermissionAnyMiddleware('repository.read',

                                              'repository.write',

                                              'repository.admin')(user,

                                                                  repo_name):

                return False

        return True

    def _get_ip_addr(self, environ):

        return _get_ip_addr(environ)

    def _check_ssl(self, environ, start_response):

        """

        Checks the SSL check flag and returns False if SSL is not present

        and required True otherwise

        """

        org_proto = environ['wsgi._org_proto']

        #check if we have SSL required  ! if not it's a bad request !

        require_ssl = str2bool(RhodeCodeUi.get_by_key('push_ssl').ui_value)

        if require_ssl and org_proto == 'http':

            log.debug('proto is %s and SSL is required BAD REQUEST !'

                      % org_proto)

            return False

        return True

    def _check_locking_state(self, environ, action, repo, user_id):

        """

        Checks locking on this repository, if locking is enabled and lock is

        present returns a tuple of make_lock, locked, locked_by.

        make_lock can have 3 states None (do nothing) True, make lock

        False release lock, This value is later propagated to hooks, which

        do the locking. Think about this as signals passed to hooks what to do.

        """

        locked = False  # defines that locked error should be thrown to user

        make_lock = None

        repo = Repository.get_by_repo_name(repo)

        user = User.get(user_id)

        # this is kind of hacky, but due to how mercurial handles client-server

        # server see all operation on changeset; bookmarks, phases and

        # obsolescence marker in different transaction, we don't want to check

        # locking on those

        obsolete_call = environ['QUERY_STRING'] in ['cmd=listkeys',]

        locked_by = repo.locked

        if repo and repo.enable_locking and not obsolete_call:

            if action == 'push':

                #check if it's already locked !, if it is compare users

                user_id, _date = repo.locked

                if user.user_id == user_id:

                    log.debug('Got push from user %s, now unlocking' % (user))

                    # unlock if we have push from user who locked

                    make_lock = False

                else:

                    # we're not the same user who locked, ban with 423 !

                    locked = True

            if action == 'pull':

                if repo.locked[0] and repo.locked[1]:

                    locked = True

                else:

                    log.debug('Setting lock on repo %s by %s' % (repo, user))

                    make_lock = True

        else:

            log.debug('Repository %s do not have locking enabled' % (repo))

        log.debug('FINAL locking values make_lock:%s,locked:%s,locked_by:%s'

                  % (make_lock, locked, locked_by))

        return make_lock, locked, locked_by

    def __call__(self, environ, start_response):

        start = time.time()

        try:

            return self._handle_request(environ, start_response)

        finally:

            log = logging.getLogger('rhodecode.' + self.__class__.__name__)

            log.debug('Request time: %.3fs' % (time.time() - start))

            meta.Session.remove()

class BaseController(WSGIController):

    def __before__(self):

        """

        __before__ is called before controller methods and after __call__

        """

        c.rhodecode_version = __version__

        c.rhodecode_instanceid = config.get('instance_id')

        c.rhodecode_name = config.get('rhodecode_title')

        c.use_gravatar = str2bool(config.get('use_gravatar'))

        c.ga_code = config.get('rhodecode_ga_code')

        # Visual options

        c.visual = AttributeDict({})

        rc_config = RhodeCodeSetting.get_app_settings()

        c.visual.show_public_icon = str2bool(rc_config.get('rhodecode_show_public_icon'))

        c.visual.show_private_icon = str2bool(rc_config.get('rhodecode_show_private_icon'))

        c.visual.stylify_metatags = str2bool(rc_config.get('rhodecode_stylify_metatags'))

        c.visual.lightweight_dashboard = str2bool(rc_config.get('rhodecode_lightweight_dashboard'))

        c.visual.lightweight_dashboard_items = safe_int(config.get('dashboard_items', 100))

        c.visual.repository_fields = str2bool(rc_config.get('rhodecode_repository_fields'))

        c.repo_name = get_repo_slug(request)

        c.backends = BACKENDS.keys()

        c.unread_notifications = NotificationModel()\

                        .get_unread_cnt_for_user(c.rhodecode_user.user_id)

        self.cut_off_limit = int(config.get('cut_off_limit'))

        self.sa = meta.Session

        self.scm_model = ScmModel(self.sa)

    def __call__(self, environ, start_response):

        """Invoke the Controller"""

        # WSGIController.__call__ dispatches to the Controller method

        # the request is routed to. This routing information is

        # available in environ['pylons.routes_dict']

        try:

            self.ip_addr = _get_ip_addr(environ)

            # make sure that we update permissions each time we call controller

            api_key = request.GET.get('api_key')

            cookie_store = CookieStoreWrapper(session.get('rhodecode_user'))

            user_id = cookie_store.get('user_id', None)

            username = get_container_username(environ, config)

            auth_user = AuthUser(user_id, api_key, username, self.ip_addr)

            request.user = auth_user

            self.rhodecode_user = c.rhodecode_user = auth_user

            if not self.rhodecode_user.is_authenticated and \

                       self.rhodecode_user.user_id is not None:

                self.rhodecode_user.set_authenticated(

                    cookie_store.get('is_authenticated')

                )

            log.info('IP: %s User: %s accessed %s' % (

               self.ip_addr, auth_user, safe_unicode(_get_access_path(environ)))

            )

            return WSGIController.__call__(self, environ, start_response)

        finally:

            meta.Session.remove()

class BaseRepoController(BaseController):

    """

    Base class for controllers responsible for loading all needed data for

    repository loaded items are

    c.rhodecode_repo: instance of scm repository

    c.rhodecode_db_repo: instance of db

    c.repository_followers: number of followers

    c.repository_forks: number of forks

    c.repository_following: weather the current user is following the current repo

    """

    def __before__(self):

        super(BaseRepoController, self).__before__()

        if c.repo_name:

            dbr = c.rhodecode_db_repo = Repository.get_by_repo_name(c.repo_name)

            c.rhodecode_repo = c.rhodecode_db_repo.scm_instance

            # update last change according to VCS data

            dbr.update_changeset_cache(dbr.get_changeset())

            if c.rhodecode_repo is None:

                log.error('%s this repository is present in database but it '

                          'cannot be created as an scm instance', c.repo_name)

                redirect(url('home'))

            # some globals counter for menu

            c.repository_followers = self.scm_model.get_followers(dbr)

            c.repository_forks = self.scm_model.get_forks(dbr)

            c.repository_pull_requests = self.scm_model.get_pull_requests(dbr)

            c.repository_following = self.scm_model.is_following_repo(c.repo_name,

                                                self.rhodecode_user.user_id)

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

"""

    rhodecode.lib.utils

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

    Some simple helper functions

    :created_on: Jan 5, 2011

    :author: marcink

    :copyright: (C) 2011-2012 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 re

import time

import datetime

import webob

from pylons.i18n.translation import _, ungettext

from rhodecode.lib.vcs.utils.lazy import LazyProperty

def __get_lem():

    """

    Get language extension map based on what's inside pygments lexers

    """

    from pygments import lexers

    from string import lower

    from collections import defaultdict

    d = defaultdict(lambda: [])

    def __clean(s):

        s = s.lstrip('*')

        s = s.lstrip('.')

        if s.find('[') != -1:

            exts = []

            start, stop = s.find('['), s.find(']')

            for suffix in s[start + 1:stop]:

                exts.append(s[:s.find('[')] + suffix)

            return map(lower, exts)

        else:

            return map(lower, [s])

    for lx, t in sorted(lexers.LEXERS.items()):

        m = map(__clean, t[-2])

        if m:

            m = reduce(lambda x, y: x + y, m)

            for ext in m:

                desc = lx.replace('Lexer', '')

                d[ext].append(desc)

    return dict(d)

def str2bool(_str):

    """

    returs True/False value from given string, it tries to translate the

    string into boolean

    :param _str: string value to translate into boolean

    :rtype: boolean

    :returns: boolean from given string

    """

    if _str is None:

        return False

    if _str in (True, False):

        return _str

    _str = str(_str).strip().lower()

    return _str in ('t', 'true', 'y', 'yes', 'on', '1')

def aslist(obj, sep=None, strip=True):

    """

    Returns given string separated by sep as list

    :param obj:

    :param sep:

    :param strip:

    """

    if isinstance(obj, (basestring)):

        lst = obj.split(sep)

        if strip:

            lst = [v.strip() for v in lst]

        return lst

    elif isinstance(obj, (list, tuple)):

        return obj

    elif obj is None:

        return []

    else:

        return [obj]

def convert_line_endings(line, mode):

    """

    Converts a given line  "line end" accordingly to given mode

    Available modes are::

        0 - Unix

        1 - Mac

        2 - DOS

    :param line: given line to convert

    :param mode: mode to convert to

    :rtype: str

    :return: converted line according to mode

    """

    from string import replace

    if mode == 0:

            line = replace(line, '\r\n', '\n')

            line = replace(line, '\r', '\n')

    elif mode == 1:

            line = replace(line, '\r\n', '\r')

            line = replace(line, '\n', '\r')

    elif mode == 2:

            line = re.sub("\r(?!\n)|(?<!\r)\n", "\r\n", line)

    return line

def detect_mode(line, default):

    """

    Detects line break for given line, if line break couldn't be found

    given default value is returned

    :param line: str line

    :param default: default

    :rtype: int

    :return: value of line end on of 0 - Unix, 1 - Mac, 2 - DOS

    """

    if line.endswith('\r\n'):

        return 2

    elif line.endswith('\n'):

        return 0

    elif line.endswith('\r'):

        return 1

    else:

        return default

def generate_api_key(username, salt=None):

    """

    Generates unique API key for given username, if salt is not given

    it'll be generated from some random string

    :param username: username as string

    :param salt: salt to hash generate KEY

    :rtype: str

    :returns: sha1 hash from username+salt

    """

    from tempfile import _RandomNameSequence

    import hashlib

    if salt is None:

        salt = _RandomNameSequence().next()

    return hashlib.sha1(username + salt).hexdigest()

def safe_int(val, default=None):

    """

    Returns int() of val if val is not convertable to int use default

    instead

    :param val:

    :param default:

    """

    try:

        val = int(val)

    except (ValueError, TypeError):

        val = default

    return val

def safe_unicode(str_, from_encoding=None):

    """

    safe unicode function. Does few trick to turn str_ into unicode

    In case of UnicodeDecode error we try to return it with encoding detected

    by chardet library if it fails fallback to unicode with errors replaced

    :param str_: string to decode

    :rtype: unicode

    :returns: unicode object

    """

    if isinstance(str_, unicode):

        return str_

    if not from_encoding:

        import rhodecode

        DEFAULT_ENCODINGS = aslist(rhodecode.CONFIG.get('default_encoding',

                                                        'utf8'), sep=',')

        from_encoding = DEFAULT_ENCODINGS

    if not isinstance(from_encoding, (list, tuple)):

        from_encoding = [from_encoding]

    try:

        return unicode(str_)

    except UnicodeDecodeError:

        pass

    for enc in from_encoding:

        try:

            return unicode(str_, enc)

        except UnicodeDecodeError:

            pass

    try:

        import chardet

        encoding = chardet.detect(str_)['encoding']

        if encoding is None:

            raise Exception()

        return str_.decode(encoding)

    except (ImportError, UnicodeDecodeError, Exception):

        return unicode(str_, from_encoding[0], 'replace')

def safe_str(unicode_, to_encoding=None):

    """

    safe str function. Does few trick to turn unicode_ into string

    In case of UnicodeEncodeError we try to return it with encoding detected

    by chardet library if it fails fallback to string with errors replaced

    :param unicode_: unicode to encode

    :rtype: str

    :returns: str object

    """

    # if it's not basestr cast to str

    if not isinstance(unicode_, basestring):

        return str(unicode_)

    if isinstance(unicode_, str):

        return unicode_

    if not to_encoding:

        import rhodecode

        DEFAULT_ENCODINGS = aslist(rhodecode.CONFIG.get('default_encoding',

                                                        'utf8'), sep=',')

        to_encoding = DEFAULT_ENCODINGS

    if not isinstance(to_encoding, (list, tuple)):

        to_encoding = [to_encoding]

    for enc in to_encoding:

        try:

            return unicode_.encode(enc)

        except UnicodeEncodeError:

            pass

    try:

        import chardet

        encoding = chardet.detect(unicode_)['encoding']

        if encoding is None:

            raise UnicodeEncodeError()

        return unicode_.encode(encoding)

    except (ImportError, UnicodeEncodeError):

        return unicode_.encode(to_encoding[0], 'replace')

    return safe_str

def remove_suffix(s, suffix):

    if s.endswith(suffix):

        s = s[:-1 * len(suffix)]

    return s

def remove_prefix(s, prefix):

    if s.startswith(prefix):

        s = s[len(prefix):]

    return s

def engine_from_config(configuration, prefix='sqlalchemy.', **kwargs):

    """

    Custom engine_from_config functions that makes sure we use NullPool for

    file based sqlite databases. This prevents errors on sqlite. This only

    applies to sqlalchemy versions < 0.7.0

    """

    import sqlalchemy

    from sqlalchemy import engine_from_config as efc

    import logging

    if int(sqlalchemy.__version__.split('.')[1]) < 7:

        # This solution should work for sqlalchemy < 0.7.0, and should use

        # proxy=TimerProxy() for execution time profiling

        from sqlalchemy.pool import NullPool

        url = configuration[prefix + 'url']

        if url.startswith('sqlite'):

            kwargs.update({'poolclass': NullPool})

        return efc(configuration, prefix, **kwargs)

    else:

        import time

        from sqlalchemy import event

        from sqlalchemy.engine import Engine

        log = logging.getLogger('sqlalchemy.engine')

        BLACK, RED, GREEN, YELLOW, BLUE, MAGENTA, CYAN, WHITE = xrange(30, 38)

        engine = efc(configuration, prefix, **kwargs)

        def color_sql(sql):

            COLOR_SEQ = "\033[1;%dm"

            COLOR_SQL = YELLOW

            normal = '\x1b[0m'

            return ''.join([COLOR_SEQ % COLOR_SQL, sql, normal])

        if configuration['debug']:

            #attach events only for debug configuration

            def before_cursor_execute(conn, cursor, statement,

                                    parameters, context, executemany):

                context._query_start_time = time.time()

                log.info(color_sql(">>>>> STARTING QUERY >>>>>"))

            def after_cursor_execute(conn, cursor, statement,

                                    parameters, context, executemany):

                total = time.time() - context._query_start_time

                log.info(color_sql("<<<<< TOTAL TIME: %f <<<<<" % total))

            event.listen(engine, "before_cursor_execute",

                         before_cursor_execute)

            event.listen(engine, "after_cursor_execute",

                         after_cursor_execute)

    return engine

def age(prevdate, show_short_version=False):

    """

    turns a datetime into an age string.

    If show_short_version is True, then it will generate a not so accurate but shorter string,

    example: 2days ago, instead of 2 days and 23 hours ago.

    :param prevdate: datetime object

    :param show_short_version: if it should aproximate the date and return a shorter string

    :rtype: unicode

    :returns: unicode words describing age

    """

    now = datetime.datetime.now()

    now = now.replace(microsecond=0)

    order = ['year', 'month', 'day', 'hour', 'minute', 'second']

    deltas = {}

    future = False

    if prevdate > now:

        now, prevdate = prevdate, now

        future = True

    # Get date parts deltas

    for part in order:

        if future:

            from dateutil import relativedelta

            d = relativedelta.relativedelta(now, prevdate)

            deltas[part] = getattr(d, part + 's')

        else:

            deltas[part] = getattr(now, part) - getattr(prevdate, part)

    # Fix negative offsets (there is 1 second between 10:59:59 and 11:00:00,

    # not 1 hour, -59 minutes and -59 seconds)

    for num, length in [(5, 60), (4, 60), (3, 24)]:  # seconds, minutes, hours

        part = order[num]

        carry_part = order[num - 1]

        if deltas[part] < 0:

            deltas[part] += length

            deltas[carry_part] -= 1

    # Same thing for days except that the increment depends on the (variable)

    # number of days in the month

    month_lengths = [31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31]

    if deltas['day'] < 0:

        if prevdate.month == 2 and (prevdate.year % 4 == 0 and

            (prevdate.year % 100 != 0 or prevdate.year % 400 == 0)):

            deltas['day'] += 29

        else:

            deltas['day'] += month_lengths[prevdate.month - 1]

        deltas['month'] -= 1

    if deltas['month'] < 0:

        deltas['month'] += 12

        deltas['year'] -= 1

    # Format the result

    fmt_funcs = {

        'year': lambda d: ungettext(u'%d year', '%d years', d) % d,

        'month': lambda d: ungettext(u'%d month', '%d months', d) % d,

        'day': lambda d: ungettext(u'%d day', '%d days', d) % d,

        'hour': lambda d: ungettext(u'%d hour', '%d hours', d) % d,

        'minute': lambda d: ungettext(u'%d minute', '%d minutes', d) % d,

        'second': lambda d: ungettext(u'%d second', '%d seconds', d) % d,

    }

    for i, part in enumerate(order):

        value = deltas[part]

        if value == 0:

            continue

        if i < 5:

            sub_part = order[i + 1]

            sub_value = deltas[sub_part]

        else:

            sub_value = 0

        if sub_value == 0 or show_short_version:

            if future:

                return _(u'in %s') % fmt_funcs[part](value)

            else:

                return _(u'%s ago') % fmt_funcs[part](value)

        if future:

            return _(u'in %s and %s') % (fmt_funcs[part](value),

                fmt_funcs[sub_part](sub_value))

        else:

            return _(u'%s and %s ago') % (fmt_funcs[part](value),

                fmt_funcs[sub_part](sub_value))

    return _(u'just now')

def uri_filter(uri):

    """

    Removes user:password from given url string

    :param uri:

    :rtype: unicode

    :returns: filtered list of strings

    """

    if not uri:

        return ''

    proto = ''

    for pat in ('https://', 'http://'):

        if uri.startswith(pat):

            uri = uri[len(pat):]

            proto = pat

            break

    # remove passwords and username

    uri = uri[uri.find('@') + 1:]

    # get the port

    cred_pos = uri.find(':')

    if cred_pos == -1:

        host, port = uri, None

    else:

        host, port = uri[:cred_pos], uri[cred_pos + 1:]

    return filter(None, [proto, host, port])

def credentials_filter(uri):

    """

    Returns a url with removed credentials

    :param uri:

    """

    uri = uri_filter(uri)

    #check if we have port

    if len(uri) > 2 and uri[2]:

        uri[2] = ':' + uri[2]

    return ''.join(uri)

def get_changeset_safe(repo, rev):

    """

    Safe version of get_changeset if this changeset doesn't exists for a

    repo it returns a Dummy one instead

    :param repo:

    :param rev:

    """

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

    from rhodecode.lib.vcs.exceptions import RepositoryError

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

    if not isinstance(repo, BaseRepository):

        raise Exception('You must pass an Repository '

                        'object as first argument got %s', type(repo))

    try:

        cs = repo.get_changeset(rev)

    except RepositoryError:

        cs = EmptyChangeset(requested_revision=rev)

    return cs

def datetime_to_time(dt):

    if dt:

        return time.mktime(dt.timetuple())

def time_to_datetime(tm):

    if tm:

        if isinstance(tm, basestring):

            try:

                tm = float(tm)

            except ValueError:

                return

        return datetime.datetime.fromtimestamp(tm)

MENTIONS_REGEX = r'(?:^@|\s@)([a-zA-Z0-9]{1}[a-zA-Z0-9\-\_\.]+)(?:\s{1})'