"""

    Returns True if request's target is mercurial server - header

    ``HTTP_ACCEPT`` of such request would start with ``application/mercurial``.

    """

    http_accept = environ.get('HTTP_ACCEPT')

    if http_accept and http_accept.startswith('application/mercurial'):

        return True

    return False

def is_git(environ):

    """

    Returns True if request's target is git server. ``HTTP_USER_AGENT`` would

    then have git client version given.

    :param environ:

    """

    http_user_agent = environ.get('HTTP_USER_AGENT')

    if http_user_agent.startswith('git'):

        return True

    return False

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

    """

    Action logger for various action made by users

    """

    if not sa:

        sa = meta.Session

    try:

        if hasattr(user, 'user_id'):

            user_id = user.user_id

        elif isinstance(user, basestring):

            user_id = sa.query(User).filter(User.username == user).one()

        else:

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

        repo_name = repo.lstrip('/')

        user_log = UserLog()

        user_log.user_id = user_id

        user_log.action = action

        user_log.repository_name = repo_name

        user_log.repository = sa.query(Repository)\

            .filter(Repository.repo_name == repo_name).one()

        user_log.action_date = datetime.datetime.now()

        user_log.user_ip = ipaddr

        sa.add(user_log)

        sa.commit()

        log.info('Adding user %s, action %s on %s',

                                        user.username, action, repo)

    except Exception, e:

        sa.rollback()

        log.error('could not log user action:%s', str(e))

def check_repo_dir(paths):

    repos_path = paths[0][1].split('/')

    if repos_path[-1] in ['*', '**']:

        repos_path = repos_path[:-1]

    if repos_path[0] != '/':

        repos_path[0] = '/'

    if not os.path.isdir(os.path.join(*repos_path)):

        raise Exception('Not a valid repository in %s' % paths[0][1])

def check_repo_fast(repo_name, base_path):

    if os.path.isdir(os.path.join(base_path, repo_name)):return False

    return True

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

@cache_region('super_short_term', 'cached_hg_ui')

def get_hg_ui_cached():

    try:

        sa = meta.Session

        ret = sa.query(RhodeCodeUi).all()