def incr_login_failed_attempts(username=None, ip=None):
    """Increase login failed attempts by 1 for both username and ip.

    Arguments:
    - `username`:
    - `ip`:

    Returns new value of failed attempts.
    """
    timeout = settings.LOGIN_ATTEMPT_TIMEOUT
    username_attempts = 1
    ip_attempts = 1

    if username:
        cache_key = normalize_cache_key(username, prefix=LOGIN_ATTEMPT_PREFIX)
        try:
            username_attempts = cache.incr(cache_key)
        except ValueError:
            cache.set(cache_key, 1, timeout)

    if ip:
        cache_key = normalize_cache_key(ip, prefix=LOGIN_ATTEMPT_PREFIX)
        try:
            ip_attempts = cache.incr(cache_key)
        except ValueError:
            cache.set(cache_key, 1, timeout)

    return max(username_attempts, ip_attempts)

def clear_login_failed_attempts(request, username):
    """Clear login failed attempts records.

    Arguments:
    - `request`:
    """
    ip = get_remote_ip(request)

    cache.delete(normalize_cache_key(username, prefix=LOGIN_ATTEMPT_PREFIX))
    cache.delete(normalize_cache_key(ip, prefix=LOGIN_ATTEMPT_PREFIX))
    p = Profile.objects.get_profile_by_user(username)
    if p and p.login_id:
        cache.delete(normalize_cache_key(p.login_id, prefix=LOGIN_ATTEMPT_PREFIX))

def refresh_cache(username):
    """
    Function to be called when change user nickname.
    """
    profile = get_first_object_or_none(Profile.objects.filter(user=username))
    nickname = profile.nickname if profile else username.split('@')[0]
    contactemail = profile.contact_email if profile else ''

    key = normalize_cache_key(username, NICKNAME_CACHE_PREFIX)
    cache.set(key, nickname, NICKNAME_CACHE_TIMEOUT)
    
    contact_key = normalize_cache_key(username, CONTACT_CACHE_PREFIX)
    cache.set(contact_key, contactemail, CONTACT_CACHE_TIMEOUT)

def _get_cache_key(request, prefix):
    """Return cache key of certain ``prefix``. If user is logged in, use
    username, otherwise use combination of request ip and user agent.

    Arguments:
    - `prefix`:
    """
    if request.user.is_authenticated():
        key = normalize_cache_key(request.user.username, 'SharedLink_')
    else:
        ip = get_remote_ip(request)
        # Memcached key length limit is 250 chars, and user agent somethings may
        # be long which will cause error.
        agent = request.META.get('HTTP_USER_AGENT', '')[:150]
        key = normalize_cache_key(ip + agent, 'SharedLink_')

    return key

def char2pinyin(value):
    """Convert Chinese character to pinyin."""

    key = normalize_cache_key(value, 'CHAR2PINYIN_')
    py = cache.get(key)
    if not py:
        py = cc.convert(value)
        cache.set(key, py, 365 * 24 * 60 * 60)

    return py

def get_login_failed_attempts(username=None, ip=None):
    """Get login failed attempts base on username and ip.
    If both username and ip are provided, return the max value.

    Arguments:
    - `username`:
    - `ip`:
    """
    if username is None and ip is None:
        return 0

    username_attempts = ip_attempts = 0

    if username:
        cache_key = normalize_cache_key(username, prefix=LOGIN_ATTEMPT_PREFIX)
        username_attempts = cache.get(cache_key, 0)

    if ip:
        cache_key = normalize_cache_key(ip, prefix=LOGIN_ATTEMPT_PREFIX)
        ip_attempts = cache.get(cache_key, 0)

    return max(username_attempts, ip_attempts)

def email2nickname(value):
    """
    Return nickname or short email.
    """
    if not value:
        return ''

    key = normalize_cache_key(value, NICKNAME_CACHE_PREFIX)
    nickname = cache.get(key)
    if not nickname:
        profile = get_first_object_or_none(Profile.objects.filter(user=value))
        nickname = profile.nickname if profile else value.split('@')[0]
        cache.set(key, nickname, NICKNAME_CACHE_TIMEOUT)
    return nickname

def ajax_get_link_audit_code(request):
    """
    Generate a token, and record that token with email in cache, expires in
    one hour, send token to that email address.

    User provide token and email at share link page, if the token and email
    are valid, record that email in session.
    """
    content_type = 'application/json; charset=utf-8'

    token = request.POST.get('token')
    email = request.POST.get('email')
    if not is_valid_email(email):
        return HttpResponse(json.dumps({
            'error': _('Email address is not valid')
        }), status=400, content_type=content_type)

    dfs = FileShare.objects.get_valid_file_link_by_token(token)
    ufs = UploadLinkShare.objects.get_valid_upload_link_by_token(token)

    fs = dfs if dfs else ufs
    if fs is None:
        return HttpResponse(json.dumps({
            'error': _('Share link is not found')
        }), status=400, content_type=content_type)

    cache_key = normalize_cache_key(email, 'share_link_audit_')
    timeout = 60 * 60           # one hour
    code = gen_token(max_length=6)
    cache.set(cache_key, code, timeout)

    # send code to user via email
    subject = _("Verification code for visiting share links")
    c = {
        'code': code,
    }
    try:
        send_html_email_with_dj_template(
            email, dj_template='share/audit_code_email.html',
            context=c, subject=subject, priority=MAIL_PRIORITY.now
        )
        return HttpResponse(json.dumps({'success': True}), status=200,
                            content_type=content_type)
    except Exception as e:
        logger.error('Failed to send audit code via email to %s')
        logger.error(e)
        return HttpResponse(json.dumps({
            "error": _("Failed to send a verification code, please try again later.")
        }), status=500, content_type=content_type)

def email2contact_email(value):
    """
    Return contact_email if it exists and it's not an empty string,
    otherwise return username(login email).
    """
    if not value:
        return ''

    key = normalize_cache_key(value, CONTACT_CACHE_PREFIX)
    contact_email = cache.get(key)
    if contact_email and contact_email.strip():
        return contact_email

    contact_email = Profile.objects.get_contact_email_by_user(value)
    cache.set(key, contact_email, CONTACT_CACHE_TIMEOUT) 
    return contact_email

    def _decorated(request, token, *args, **kwargs):
        assert token is not None    # Checked by URLconf

        fileshare = FileShare.objects.get_valid_file_link_by_token(token) or \
                    FileShare.objects.get_valid_dir_link_by_token(token) or \
                    UploadLinkShare.objects.get_valid_upload_link_by_token(token)

        if fileshare is None:
            raise Http404

        if not is_pro_version() or not settings.ENABLE_SHARE_LINK_AUDIT:
            return func(request, fileshare, *args, **kwargs)

        # no audit for authenticated user, since we've already got email address
        if request.user.is_authenticated():
            return func(request, fileshare, *args, **kwargs)

        # anonymous user
        if request.session.get('anonymous_email') is not None:
            request.user.username = request.session.get('anonymous_email')
            return func(request, fileshare, *args, **kwargs)

        if request.method == 'GET':
            return render_to_response('share/share_link_audit.html', {
                'token': token,
            }, context_instance=RequestContext(request))
        elif request.method == 'POST':
            code = request.POST.get('code', '')
            email = request.POST.get('email', '')

            cache_key = normalize_cache_key(email, 'share_link_audit_')
            if code == cache.get(cache_key):
                # code is correct, add this email to session so that he will
                # not be asked again during this session, and clear this code.
                request.session['anonymous_email'] = email
                request.user.username = request.session.get('anonymous_email')
                cache.delete(cache_key)
                return func(request, fileshare, *args, **kwargs)
            else:
                return render_to_response('share/share_link_audit.html', {
                    'err_msg': 'Invalid token, please try again.',
                    'email': email,
                    'code': code,
                    'token': token,
                }, context_instance=RequestContext(request))
        else:
            assert False, 'TODO'

def group_id_to_name(group_id):

    group_id = str(group_id)

    key = normalize_cache_key(group_id, GROUP_ID_CACHE_PREFIX)
    cached_group_name = cache.get(key)
    if cached_group_name:
        return cached_group_name

    group = ccnet_api.get_group(int(group_id))
    if not group:
        return ''

    group_name = group.group_name
    cache.set(key, group_name, GROUP_ID_CACHE_TIMEOUT)

    return group_name

    def test_anonymous_user_post_correct_token(self, mock_is_pro_version):
        """
        Check that anonnymous user input email and correct verification code.
        """
        mock_is_pro_version.return_value = True

        code = gen_token(max_length=6)
        email = '[email protected]'
        cache_key = normalize_cache_key(email, 'share_link_audit_')
        cache.set(cache_key, code, timeout=60)
        assert cache.get(cache_key) == code

        anon_req = self._anon_post_request(data={'code': code, 'email': email})
        self.assertEqual(anon_req.session.get('anonymous_email'), None)
        resp = self._fake_view_shared_file(anon_req, self.fs.token)

        self.assertEqual(resp.status_code, 200)
        self.assertEqual(anon_req.session.get('anonymous_email'), email)  # email is set in session
        assert cache.get(cache_key) is None  # token is delete after used

def email2id(value):
    """
    Return the user id of an email. User id can be 0(ldap user),
    positive(registered user) or negtive(unregistered user).
    
    """
    if not value:
        return -1

    key = normalize_cache_key(value, EMAIL_ID_CACHE_PREFIX)
    user_id = cache.get(key)
    if not user_id:
        try:
            user = User.objects.get(email=value)
            user_id = user.id
        except User.DoesNotExist:
            user_id = -1
        cache.set(key, user_id, EMAIL_ID_CACHE_TIMEOUT)
    return user_id

def email2nickname(value):
    """
    Return nickname if it exists and it's not an empty string,
    otherwise return short email.
    """
    if not value:
        return ''

    key = normalize_cache_key(value, NICKNAME_CACHE_PREFIX)
    cached_nickname = cache.get(key)
    if cached_nickname and cached_nickname.strip():
        return cached_nickname.strip()

    profile = get_first_object_or_none(Profile.objects.filter(user=value))
    if profile is not None and profile.nickname and profile.nickname.strip():
        nickname = profile.nickname.strip()
    else:
        nickname = value.split('@')[0]

    cache.set(key, nickname, NICKNAME_CACHE_TIMEOUT)
    return nickname

def clean_email_id_cache(sender, **kwargs):
    from seahub.utils import normalize_cache_key
    
    user = kwargs['user']
    key = normalize_cache_key(user.email, EMAIL_ID_CACHE_PREFIX)
    cache.set(key, user.id, EMAIL_ID_CACHE_TIMEOUT)

def update_user_info(request, user):

    # update basic user info
    password = request.data.get("password")
    if password:
        user.set_password(password)

    is_staff = request.data.get("is_staff")
    if is_staff:
        is_staff = to_python_boolean(is_staff)
        user.is_staff = is_staff

    is_active = request.data.get("is_active")
    if is_active:
        is_active = to_python_boolean(is_active)
        user.is_active = is_active

    # update user
    user.save()

    email = user.username

    # update additional user info
    if is_pro_version():
        role = request.data.get("role")
        if role:
            User.objects.update_role(email, role)

    nickname = request.data.get("name", None)
    if nickname is not None:
        Profile.objects.add_or_update(email, nickname)

    # update account login_id
    login_id = request.data.get("login_id", None)
    if login_id is not None:
        Profile.objects.add_or_update(email, login_id=login_id)

    # update account contact email
    contact_email = request.data.get('contact_email', None)
    if contact_email is not None:
        Profile.objects.add_or_update(email, contact_email=contact_email)
        key = normalize_cache_key(email, CONTACT_CACHE_PREFIX)
        cache.set(key, contact_email, CONTACT_CACHE_TIMEOUT)

    reference_id = request.data.get("reference_id", None)
    if reference_id is not None:
        if reference_id.strip():
            ccnet_api.set_reference_id(email, reference_id.strip())
        else:
            # remove reference id
            ccnet_api.set_reference_id(email, None)

    department = request.data.get("department")
    if department:
        d_profile = DetailedProfile.objects.get_detailed_profile_by_user(email)
        if d_profile is None:
            d_profile = DetailedProfile(user=email)

        d_profile.department = department
        d_profile.save()

    quota_total_mb = request.data.get("quota_total")
    if quota_total_mb:
        quota_total = int(quota_total_mb) * get_file_size_unit('MB')
        if is_org_context(request):
            org_id = request.user.org.org_id
            seafile_api.set_org_user_quota(org_id, email, quota_total)
        else:
            seafile_api.set_user_quota(email, quota_total)

def get_cache_key_of_unseen_notifications(username):
    return normalize_cache_key(username,
            USER_NOTIFICATION_COUNT_CACHE_PREFIX)