['1-2.a_X', '1234', 'ddd', 'ee', 'ff', 'gg', 'gg', 'hh', 'zz']

    """

    return MENTIONS_REGEX.findall(text)

def extract_mentioned_users(text):

    """ Returns set of actual database Users @mentioned in given text. """

    from kallithea.model.db import User

    result = set()

    for name in extract_mentioned_usernames(text):

        user = User.get_by_username(name, case_insensitive=True)

        if user is not None and not user.is_default_user:

            result.add(user)

    return result

class AttributeDict(dict):

    def __getattr__(self, attr):

        return self.get(attr, None)

    __setattr__ = dict.__setitem__

    __delattr__ = dict.__delitem__

def obfuscate_url_pw(engine):

    from sqlalchemy.engine import url as sa_url

    from sqlalchemy.exc import ArgumentError

    try:

        _url = sa_url.make_url(engine or '')

    except ArgumentError:

        return engine

    if _url.password:

        _url.password = 'XXXXX'

    return str(_url)

class HookEnvironmentError(Exception): pass

def get_hook_environment():

    """

    Get hook context by deserializing the global KALLITHEA_EXTRAS environment

    variable.

    Called early in Git out-of-process hooks to get .ini config path so the

    basic environment can be configured properly. Also used in all hooks to get

    information about the action that triggered it.

    """

    try:

        kallithea_extras = os.environ['KALLITHEA_EXTRAS']

    except KeyError:

        raise HookEnvironmentError("Environment variable KALLITHEA_EXTRAS not found")

    extras = json.loads(kallithea_extras)

    for k in ['username', 'repository', 'scm', 'action', 'ip', 'config']:

        try:

            extras[k]

        except KeyError:

            raise HookEnvironmentError('Missing key %s in KALLITHEA_EXTRAS %s' % (k, extras))

    return AttributeDict(extras)

def set_hook_environment(username, ip_addr, repo_name, repo_alias, action=None):

    """Prepare global context for running hooks by serializing data in the

    global KALLITHEA_EXTRAS environment variable.

    Most importantly, this allow Git hooks to do proper logging and updating of

    caches after pushes.

    Must always be called before anything with hooks are invoked.

    """

    from kallithea import CONFIG

    extras = {

        'ip': ip_addr, # used in log_push/pull_action action_logger

        'username': username,

        'action': action or 'push_local', # used in log_push_action_raw_ids action_logger

        'repository': repo_name,

        'scm': repo_alias, # used to pick hack in log_push_action_raw_ids

        'config': CONFIG['__file__'], # used by git hook to read config

    }

    os.environ['KALLITHEA_EXTRAS'] = json.dumps(extras)

def get_current_authuser():

    """

    Gets kallithea user from threadlocal tmpl_context variable if it's

    defined, else returns None.

    """

    from tg import tmpl_context

    try:

        return getattr(tmpl_context, 'authuser', None)

    except TypeError:  # No object (name: context) has been registered for this thread

        return None

class Optional(object):

    """

    Defines an optional parameter::

        param = param.getval() if isinstance(param, Optional) else param

        param = param() if isinstance(param, Optional) else param

    is equivalent of::

        param = Optional.extract(param)

    """

    def __init__(self, type_):

        self.type_ = type_

    def __repr__(self):

        return '<Optional:%s>' % self.type_.__repr__()

    def __call__(self):

        return self.getval()

    def getval(self):

        """

        returns value from this Optional instance

        """

        return self.type_

    @classmethod

    def extract(cls, val):

        """

        Extracts value from Optional() instance

        :param val:

        :return: original value if it's not Optional instance else

            value of instance

        """

        if isinstance(val, cls):

            return val.getval()

        return val

def urlreadable(s, _cleanstringsub=re.compile('[^-a-zA-Z0-9./]+').sub):

    return _cleanstringsub('_', s).rstrip('_')

def recursive_replace(str_, replace=' '):

    """

    Recursive replace of given sign to just one instance

    :param str_: given string

    :param replace: char to find and replace multiple instances

    Examples::

    >>> recursive_replace("Mighty---Mighty-Bo--sstones",'-')

    'Mighty-Mighty-Bo-sstones'

    """

    if str_.find(replace * 2) == -1:

        return str_

    else:

        str_ = str_.replace(replace * 2, replace)

        return recursive_replace(str_, replace)

def repo_name_slug(value):

    """

    Return slug of name of repository

    This function is called on each creation/modification

    of repository to prevent bad names in repo

    """

    slug = remove_formatting(value)

    slug = strip_tags(slug)

    for c in r"""`?=[]\;'"<>,/~!@#$%^&*()+{}|: """:

        slug = slug.replace(c, '-')

    slug = recursive_replace(slug, '-')

    slug = collapse(slug, '-')

    return slug

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

    while True:

        ok = 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)

    Builds API data with given random ID

    For convenience, the json is returned as str

    """

    random_id = random.randrange(1, 9999)

    return random_id, ext_json.dumps({

        "id": random_id,

        "api_key": apikey,

        "method": method,

        "args": kw

    })

jsonify = lambda obj: ext_json.loads(ext_json.dumps(obj))

def api_call(test_obj, params):

    response = test_obj.app.post(API_URL, content_type='application/json',

                                 params=params)

    return response

## helpers

def make_user_group(name=TEST_USER_GROUP):

    gr = fixture.create_user_group(name, cur_user=base.TEST_USER_ADMIN_LOGIN)

    UserGroupModel().add_user_to_group(user_group=gr,

                                       user=base.TEST_USER_ADMIN_LOGIN)

    Session().commit()

    return gr

def make_repo_group(name=TEST_REPO_GROUP):

    gr = fixture.create_repo_group(name, cur_user=base.TEST_USER_ADMIN_LOGIN)

    Session().commit()

    return gr

class _BaseTestApi(object):

    REPO = None

    REPO_TYPE = None

    @classmethod

    def setup_class(cls):

        cls.usr = User.get_by_username(base.TEST_USER_ADMIN_LOGIN)

        cls.apikey = cls.usr.api_key

        cls.test_user = UserModel().create_or_update(

            username='test-api',

            password='test',

            email='test@example.com',

            firstname='first',

            lastname='last'

        )

        Session().commit()

        cls.TEST_USER_LOGIN = cls.test_user.username

        cls.apikey_regular = cls.test_user.api_key

    @classmethod

    def teardown_class(cls):

        pass

    def setup_method(self, method):

        make_user_group()

        make_repo_group()

    def teardown_method(self, method):

        fixture.destroy_user_group(TEST_USER_GROUP)

        fixture.destroy_gists()

        fixture.destroy_repo_group(TEST_REPO_GROUP)

    def _compare_ok(self, id_, expected, given):

        expected = jsonify({

            'id': id_,

            'error': None,

            'result': expected

        })

        given = ext_json.loads(given)

        assert expected == given, (expected, given)

    def _compare_error(self, id_, expected, given):

        expected = jsonify({

            'id': id_,

            'error': expected,

            'result': None

        })

        given = ext_json.loads(given)

        assert expected == given, (expected, given)

    def test_Optional_object(self):

        from kallithea.controllers.api.api import Optional

        option1 = Optional(None)

        assert '<Optional:%s>' % None == repr(option1)

        assert option1() is None

        assert 1 == Optional.extract(Optional(1))

        assert 'trololo' == Optional.extract('trololo')

    def test_api_wrong_key(self):

        id_, params = _build_data('trololo', 'get_user')

        response = api_call(self, params)

        expected = 'Invalid API key'

        self._compare_error(id_, expected, given=response.body)

    def test_api_missing_non_optional_param(self):

        id_, params = _build_data(self.apikey, 'get_repo')

        response = api_call(self, params)

        expected = 'Missing non optional `repoid` arg in JSON DATA'

        self._compare_error(id_, expected, given=response.body)

    def test_api_missing_non_optional_param_args_null(self):

        id_, params = _build_data(self.apikey, 'get_repo')

        params = params.replace('"args": {}', '"args": null')

        response = api_call(self, params)

        expected = 'Missing non optional `repoid` arg in JSON DATA'

        self._compare_error(id_, expected, given=response.body)

    def test_api_missing_non_optional_param_args_bad(self):

        id_, params = _build_data(self.apikey, 'get_repo')

        params = params.replace('"args": {}', '"args": 1')

        response = api_call(self, params)

        expected = 'Missing non optional `repoid` arg in JSON DATA'

        self._compare_error(id_, expected, given=response.body)

    def test_api_args_is_null(self):

        id_, params = _build_data(self.apikey, 'get_users', )

        params = params.replace('"args": {}', '"args": null')

        response = api_call(self, params)

        assert response.status == '200 OK'

    def test_api_args_is_bad(self):

        id_, params = _build_data(self.apikey, 'get_users', )

        params = params.replace('"args": {}', '"args": 1')

        response = api_call(self, params)

        assert response.status == '200 OK'

    def test_api_args_different_args(self):

        import string

        expected = {

            'ascii_letters': string.ascii_letters,

            'ws': string.whitespace,

            'printables': string.printable

        }

        id_, params = _build_data(self.apikey, 'test', args=expected)

        response = api_call(self, params)

        assert response.status == '200 OK'

        self._compare_ok(id_, expected, response.body)

    def test_api_get_users(self):

        id_, params = _build_data(self.apikey, 'get_users', )

        response = api_call(self, params)

        ret_all = []

        _users = User.query().filter_by(is_default_user=False) \

            .order_by(User.username).all()

        for usr in _users:

            ret = usr.get_api_data()

            ret_all.append(jsonify(ret))

        expected = ret_all

        self._compare_ok(id_, expected, given=response.body)

    def test_api_get_user(self):

        id_, params = _build_data(self.apikey, 'get_user',

                                  userid=base.TEST_USER_ADMIN_LOGIN)

        response = api_call(self, params)

        usr = User.get_by_username(base.TEST_USER_ADMIN_LOGIN)

        ret = usr.get_api_data()

        ret['permissions'] = AuthUser(dbuser=usr).permissions

        expected = ret

        self._compare_ok(id_, expected, given=response.body)

    def test_api_get_user_that_does_not_exist(self):

        id_, params = _build_data(self.apikey, 'get_user',

                                  userid='trololo')

        response = api_call(self, params)

        expected = "user `%s` does not exist" % 'trololo'

        self._compare_error(id_, expected, given=response.body)

    def test_api_get_user_without_giving_userid(self):

        id_, params = _build_data(self.apikey, 'get_user')

        response = api_call(self, params)

        usr = User.get_by_username(base.TEST_USER_ADMIN_LOGIN)

        ret = usr.get_api_data()

        ret['permissions'] = AuthUser(dbuser=usr).permissions

        expected = ret

        self._compare_ok(id_, expected, given=response.body)