:return: repo_name if matched else None

    """

    _repo_id = _extract_id_from_repo_name(repo_name)

    if _repo_id:

        from kallithea.model.db import Repository

        repo = Repository.get(_repo_id)

        if repo:

            # TODO: return repo instead of reponame? or would that be a layering violation?

            return repo.repo_name

    return None

def action_logger(user, action, repo, ipaddr='', sa=None, commit=False):

    """

    Action logger for various actions made by users

    :param user: user that made this action, can be a unique username string or

        object containing user_id attribute

    :param action: action to log, should be on of predefined unique actions for

        easy translations

    :param repo: string name of repository or object containing repo_id,

        that action was made on

    :param ipaddr: optional IP address from what the action was made

    :param sa: optional sqlalchemy session

    """

    if not sa:

        sa = meta.Session()

    # if we don't get explicit IP address try to get one from registered user

    # in tmpl context var

    if not ipaddr:

        ipaddr = getattr(get_current_authuser(), 'ip_addr', '')

    if getattr(user, 'user_id', None):

        user_obj = User.get(user.user_id)

    elif isinstance(user, basestring):

        user_obj = User.get_by_username(user)

    else:

        raise Exception('You have to provide a user object or a username')

    if getattr(repo, 'repo_id', None):

        repo_obj = Repository.get(repo.repo_id)

        repo_name = repo_obj.repo_name

    elif isinstance(repo, basestring):

        repo_name = repo.lstrip('/')

        repo_obj = Repository.get_by_repo_name(repo_name)

    else:

        repo_obj = None

        repo_name = u''

    user_log = UserLog()

    user_log.user_id = user_obj.user_id

    user_log.username = user_obj.username

    user_log.action = safe_unicode(action)

    user_log.repository = repo_obj

    user_log.repository_name = repo_name

    user_log.action_date = datetime.datetime.now()

    user_log.user_ip = ipaddr

    sa.add(user_log)

    log.info('Logging action:%s on %s by user:%s ip:%s',

             action, safe_unicode(repo), user_obj, ipaddr)

    if commit:

        sa.commit()

def get_filesystem_repos(path):

    """

    Scans given path for repos and return (name,(type,path)) tuple

    :param path: path to scan for repositories

    :param recursive: recursive search and return names with subdirs in front

    """

    # remove ending slash for better results

    path = safe_str(path.rstrip(os.sep))

    log.debug('now scanning in %s', path)

    def isdir(*n):

        return os.path.isdir(os.path.join(*n))

    for root, dirs, _files in os.walk(path):

        recurse_dirs = []

        for subdir in dirs:

            # skip removed repos

            if REMOVED_REPO_PAT.match(subdir):

                continue

            #skip .<something> dirs TODO: rly? then we should prevent creating them ...

            if subdir.startswith('.'):

                continue

            cur_path = os.path.join(root, subdir)

            if (isdir(cur_path, '.hg') or

                isdir(cur_path, '.svn') or

                isdir(cur_path, 'objects') and (isdir(cur_path, 'refs') or

                                                os.path.isfile(os.path.join(cur_path, 'packed-refs')))):

                if not os.access(cur_path, os.R_OK) or not os.access(cur_path, os.X_OK):

                    log.warning('ignoring repo path without access: %s', cur_path)

                    continue

                if not os.access(cur_path, os.W_OK):

                    log.warning('repo path without write access: %s', cur_path)

                try:

                    scm_info = get_scm(cur_path)

                    assert cur_path.startswith(path)

                    repo_path = cur_path[len(path) + 1:]

                    yield repo_path, scm_info

                    continue # no recursion

                except VCSError:

                    # We should perhaps ignore such broken repos, but especially

                    # the bare git detection is unreliable so we dive into it

                    pass

            recurse_dirs.append(subdir)

        dirs[:] = recurse_dirs

def is_valid_repo(repo_name, base_path, scm=None):

    """

    Returns True if given path is a valid repository False otherwise.

    If scm param is given also compare if given scm is the same as expected

    from scm parameter

    :param repo_name:

    :param base_path:

    :param scm:

    :return True: if given path is a valid repository

    """

    full_path = os.path.join(safe_str(base_path), safe_str(repo_name))

    try:

        scm_ = get_scm(full_path)

        if scm:

            return scm_[0] == scm

        return True

    except VCSError:

        return False

def is_valid_repo_group(repo_group_name, base_path, skip_path_check=False):

    """

    Returns True if given path is a repository group False otherwise

    :param repo_name:

    :param base_path:

    """

    full_path = os.path.join(safe_str(base_path), safe_str(repo_group_name))

    # check if it's not a repo

    if is_valid_repo(repo_group_name, base_path):

        return False

    try:

        # we need to check bare git repos at higher level

        # since we might match branches/hooks/info/objects or possible

        # other things inside bare git repo

        get_scm(os.path.dirname(full_path))

        return False

    except VCSError:

        pass

    # check if it's a valid path

    if skip_path_check or os.path.isdir(full_path):

        return True

    return False

#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, clear_session=True):

    """

    A function that will read python rc files or database

    and make an mercurial ui object from read options