def create_realm(request, creation_key=None):
    # type: (HttpRequest, Optional[Text]) -> HttpResponse
    if not settings.OPEN_REALM_CREATION:
        if creation_key is None:
            return render_to_response("zerver/realm_creation_failed.html",
                                      {'message': _('New organization creation disabled.')})
        elif not check_key_is_valid(creation_key):
            return render_to_response("zerver/realm_creation_failed.html",
                                      {'message': _('The organization creation link has expired'
                                                    ' or is not valid.')})

    # When settings.OPEN_REALM_CREATION is enabled, anyone can create a new realm,
    # subject to a few restrictions on their email address.
    if request.method == 'POST':
        form = RealmCreationForm(request.POST)
        if form.is_valid():
            email = form.cleaned_data['email']
            confirmation_key = send_registration_completion_email(email, request, realm_creation=True).confirmation_key
            if settings.DEVELOPMENT:
                request.session['confirmation_key'] = {'confirmation_key': confirmation_key}
            if (creation_key is not None and check_key_is_valid(creation_key)):
                RealmCreationKey.objects.get(creation_key=creation_key).delete()
            return HttpResponseRedirect(reverse('send_confirm', kwargs={'email': email}))
        try:
            email = request.POST['email']
            user_email_is_unique(email)
        except ValidationError:
            # Maybe the user is trying to log in
            return redirect_to_email_login_url(email)
    else:
        form = RealmCreationForm()
    return render_to_response('zerver/create_realm.html',
                              {'form': form, 'current_url': request.get_full_path},
                              request=request)

def create_realm(request, creation_key=None):
    # type: (HttpRequest, Optional[text_type]) -> HttpResponse
    if not settings.OPEN_REALM_CREATION:
        if creation_key is None:
            return render_to_response("zerver/realm_creation_failed.html",
                                      {'message': _('New organization creation disabled.')})
        elif not check_key_is_valid(creation_key):
            return render_to_response("zerver/realm_creation_failed.html",
                                      {'message': _('The organization creation link has been expired'
                                                    ' or is not valid.')})

    if request.method == 'POST':
        form = RealmCreationForm(request.POST, domain=request.session.get("domain"))
        if form.is_valid():
            email = form.cleaned_data['email']
            confirmation_key = send_registration_completion_email(email, request, realm_creation=True).confirmation_key
            if settings.DEVELOPMENT:
                 request.session['confirmation_key'] = {'confirmation_key': confirmation_key}
            if (creation_key is not None and check_key_is_valid(creation_key)):
                RealmCreationKey.objects.get(creation_key=creation_key).delete()
            return HttpResponseRedirect(reverse('send_confirm', kwargs={'email': email}))
        try:
            email = request.POST['email']
            user_email_is_unique(email)
        except ValidationError:
            # if the user user is already registered he can't create a new realm as a realm
            # with the same domain as user's email already exists
            return redirect_to_email_login_url(email)
    else:
        form = RealmCreationForm(domain=request.session.get("domain"))
    return render_to_response('zerver/create_realm.html',
                              {'form': form, 'current_url': request.get_full_path},
                              request=request)

def process_unsubscribe(token, subscription_type, unsubscribe_function):
    # type: (HttpRequest, str, Callable[[UserProfile], None]) -> HttpResponse
    try:
        confirmation = Confirmation.objects.get(confirmation_key=token)
    except Confirmation.DoesNotExist:
        return render_to_response('zerver/unsubscribe_link_error.html')

    user_profile = confirmation.content_object
    unsubscribe_function(user_profile)
    context = common_context(user_profile)
    context.update({"subscription_type": subscription_type})
    return render_to_response('zerver/unsubscribe_success.html', context)

def api_endpoint_docs(request):
    # type: (HttpRequest) -> HttpResponse
    context = {} # type: Dict[str, Any]
    add_api_uri_context(context, request)

    raw_calls = open('templates/zerver/api_content.json', 'r').read()
    calls = ujson.loads(raw_calls)
    langs = set()
    for call in calls:
        call["endpoint"] = "%s/v1/%s" % (context["external_api_uri_subdomain"],
                                         call["endpoint"])
        call["example_request"]["curl"] = call["example_request"]["curl"].replace("https://api.zulip.com",
                                                                                  context["external_api_uri_subdomain"])
        response = call['example_response']
        if '\n' not in response:
            # For 1-line responses, pretty-print them
            extended_response = response.replace(", ", ",\n ")
        else:
            extended_response = response
        call['rendered_response'] = bugdown.convert("~~~ .py\n" + extended_response + "\n~~~\n",
                                                    realm_filters_key=bugdown.DEFAULT_BUGDOWN_KEY)
        for example_type in ('request', 'response'):
            for lang in call.get('example_' + example_type, []):
                langs.add(lang)
    return render_to_response(
            'zerver/api_endpoints.html', {
                'content': calls,
                'langs': langs,
                },
            request=request)

def maybe_send_to_registration(request, email, full_name=''):
    # type: (HttpRequest, text_type, text_type) -> HttpResponse
    form = create_homepage_form(request, user_info={'email': email})
    request.verified_email = None
    if form.is_valid():
        # Construct a PreregistrationUser object and send the user over to
        # the confirmation view.
        prereg_user = None
        if settings.ONLY_SSO:
            try:
                prereg_user = PreregistrationUser.objects.filter(email__iexact=email).latest("invited_at")
            except PreregistrationUser.DoesNotExist:
                prereg_user = create_preregistration_user(email, request)
        else:
            prereg_user = create_preregistration_user(email, request)

        return redirect("".join((
            settings.EXTERNAL_URI_SCHEME,
            request.get_host(),
            "/",
            # Split this so we only get the part after the /
            Confirmation.objects.get_link_for_object(prereg_user).split("/", 3)[3],
            '?full_name=',
            # urllib does not handle Unicode, so coerece to encoded byte string
            # Explanation: http://stackoverflow.com/a/5605354/90777
            urllib.parse.quote_plus(full_name.encode('utf8')))))
    else:
        url = reverse('register')
        return render_to_response('zerver/accounts_home.html',
                                  {'form': form, 'current_url': lambda: url},
                                  request=request)

def find_my_team(request):
    # type: (HttpRequest) -> HttpResponse
    url = reverse('zerver.views.registration.find_my_team')

    emails = []  # type: List[Text]
    if request.method == 'POST':
        form = FindMyTeamForm(request.POST)
        if form.is_valid():
            emails = form.cleaned_data['emails']
            for user_profile in UserProfile.objects.filter(email__in=emails):
                send_find_my_team_emails(user_profile)

            # Note: Show all the emails in the result otherwise this
            # feature can be used to ascertain which email addresses
            # are associated with Zulip.
            data = urllib.parse.urlencode({'emails': ','.join(emails)})
            return redirect(url + "?" + data)
    else:
        form = FindMyTeamForm()
        result = request.GET.get('emails')
        if result:
            for email in result.split(','):
                try:
                    validators.validate_email(email)
                    emails.append(email)
                except ValidationError:
                    pass

    return render_to_response('zerver/find_my_team.html',
                              {'form': form, 'current_url': lambda: url,
                               'emails': emails},
                              request=request)

def process_unsubscribe(token, subscription_type, unsubscribe_function):
    # type: (HttpRequest, str, Callable[[UserProfile], None]) -> HttpResponse
    try:
        confirmation = Confirmation.objects.get(confirmation_key=token)
    except Confirmation.DoesNotExist:
        return render_to_response('zerver/unsubscribe_link_error.html')

    user_profile = confirmation.content_object
    unsubscribe_function(user_profile)
    return render_to_response('zerver/unsubscribe_success.html',
                              {"subscription_type": subscription_type,
                               "external_host": settings.EXTERNAL_HOST,
                               'external_uri_scheme': settings.EXTERNAL_URI_SCHEME,
                               'server_uri': settings.SERVER_URI,
                               'realm_uri': user_profile.realm.uri,
                              })

def email_unsubscribe(request, type, token):
    # type: (HttpRequest, str, str) -> HttpResponse
    if type in email_unsubscribers:
        display_name, unsubscribe_function = email_unsubscribers[type]
        return process_unsubscribe(token, display_name, unsubscribe_function)

    return render_to_response('zerver/unsubscribe_link_error.html', {},
                              request=request)

def home(request):
    # type: (HttpRequest) -> HttpResponse
    if settings.DEVELOPMENT and os.path.exists('var/handlebars-templates/compile.error'):
        response = render_to_response('zerver/handlebars_compilation_failed.html',
                                      request=request)
        response.status_code = 500
        return response
    if not settings.SUBDOMAINS_HOMEPAGE:
        return home_real(request)

    # If settings.SUBDOMAINS_HOMEPAGE, sends the user the landing
    # page, not the login form, on the root domain

    subdomain = get_subdomain(request)
    if subdomain != "":
        return home_real(request)

    return render_to_response('zerver/hello.html',
                              request=request)

def authors_view(request):
    # type: (HttpRequest) -> HttpResponse

    with open(settings.CONTRIBUTORS_DATA) as f:
        data = json.load(f)

    return render_to_response(
        'zerver/authors.html',
        data,
        request=request
    )

    def process_response(self, request, response):
        # type: (HttpRequest, HttpResponse) -> HttpResponse
        if settings.REALMS_HAVE_SUBDOMAINS:
            if (not request.path.startswith("/static/") and not request.path.startswith("/api/")
                and not request.path.startswith("/json/")):
                subdomain = get_subdomain(request)
                if (request.get_host() == "127.0.0.1:9991" or request.get_host() == "localhost:9991"):
                    return redirect("%s%s" % (settings.EXTERNAL_URI_SCHEME,
                                              settings.EXTERNAL_HOST))
                if subdomain != "":
                    realm = resolve_subdomain_to_realm(subdomain)
                    if (realm is None):
                        return render_to_response("zerver/invalid_realm.html")
        """
        If request.session was modified, or if the configuration is to save the
        session every time, save the changes and set a session cookie.
        """
        try:
            accessed = request.session.accessed
            modified = request.session.modified
        except AttributeError:
            pass
        else:
            if accessed:
                patch_vary_headers(response, ('Cookie',))
            if modified or settings.SESSION_SAVE_EVERY_REQUEST:
                if request.session.get_expire_at_browser_close():
                    max_age = None
                    expires = None
                else:
                    max_age = request.session.get_expiry_age()
                    expires_time = time.time() + max_age
                    expires = cookie_date(expires_time)
                # Save the session data and refresh the client cookie.
                # Skip session save for 500 responses, refs #3881.
                if response.status_code != 500:
                    request.session.save()
                    host = request.get_host().split(':')[0]

                    session_cookie_domain = settings.SESSION_COOKIE_DOMAIN
                    # The subdomains feature overrides the
                    # SESSION_COOKIE_DOMAIN setting, since the setting
                    # is a fixed value and with subdomains enabled,
                    # the session cookie domain has to vary with the
                    # subdomain.
                    if settings.REALMS_HAVE_SUBDOMAINS:
                        session_cookie_domain = host
                    response.set_cookie(settings.SESSION_COOKIE_NAME,
                            request.session.session_key, max_age=max_age,
                            expires=expires, domain=session_cookie_domain,
                            path=settings.SESSION_COOKIE_PATH,
                            secure=settings.SESSION_COOKIE_SECURE or None,
                            httponly=settings.SESSION_COOKIE_HTTPONLY or None)
        return response

def home(request):
    # type: (HttpRequest) -> HttpResponse
    if not settings.SUBDOMAINS_HOMEPAGE:
        return home_real(request)

    # If settings.SUBDOMAINS_HOMEPAGE, sends the user the landing
    # page, not the login form, on the root domain

    subdomain = get_subdomain(request)
    if subdomain != "":
        return home_real(request)

    return render_to_response('zerver/hello.html',
                              request=request)

def accounts_accept_terms(request):
    # type: (HttpRequest) -> HttpResponse
    if request.method == "POST":
        form = ToSForm(request.POST)
        if form.is_valid():
            do_change_tos_version(request.user, settings.TOS_VERSION)
            return redirect(home)
    else:
        form = ToSForm()

    email = request.user.email
    special_message_template = None
    if request.user.tos_version is None and settings.FIRST_TIME_TOS_TEMPLATE is not None:
        special_message_template = 'zerver/' + settings.FIRST_TIME_TOS_TEMPLATE
    return render_to_response('zerver/accounts_accept_terms.html',
        {'form': form, 'email': email, 'special_message_template': special_message_template},
        request=request)

def get_activity(request):
    # type: (HttpRequest) -> HttpResponse
    duration_content, realm_minutes = user_activity_intervals() # type: Tuple[mark_safe, Dict[str, float]]
    counts_content = realm_summary_table(realm_minutes) # type: str
    data = [
        ('Counts', counts_content),
        ('Durations', duration_content),
    ]
    for page in ad_hoc_queries():
        data.append((page['title'], page['content']))

    title = 'Activity'

    return render_to_response(
        'analytics/activity.html',
        dict(data=data, title=title, is_home=True),
        request=request
    )

def accounts_home(request):
    # type: (HttpRequest) -> HttpResponse
    if request.method == 'POST':
        form = create_homepage_form(request, user_info=request.POST)
        if form.is_valid():
            email = form.cleaned_data['email']
            send_registration_completion_email(email, request)
            return HttpResponseRedirect(reverse('send_confirm', kwargs={'email': email}))
        try:
            email = request.POST['email']
            # Note: We don't check for uniqueness
            is_inactive(email)
        except ValidationError:
            return redirect_to_email_login_url(email)
    else:
        form = create_homepage_form(request)
    return render_to_response('zerver/accounts_home.html',
                              {'form': form, 'current_url': request.get_full_path},
                              request=request)

def get_user_activity(request, email):
    # type: (HttpRequest, str) -> HttpResponse
    records = get_user_activity_records_for_email(email)

    data = [] # type: List[Tuple[str, str]]
    user_summary = get_user_activity_summary(records)
    content = user_activity_summary_table(user_summary)

    data += [('Summary', content)]

    content = raw_user_activity_table(records)
    data += [('Info', content)]

    title = email
    return render_to_response(
        'analytics/activity.html',
        dict(data=data, title=title),
        request=request
    )

def get_realm_activity(request, realm_str):
    # type: (HttpRequest, str) -> HttpResponse
    data = [] # type: List[Tuple[str, str]]
    all_user_records = {} # type: Dict[str, Any]

    try:
        admins = Realm.objects.get(string_id=realm_str).get_admin_users()
    except Realm.DoesNotExist:
        return HttpResponseNotFound("Realm %s does not exist" % (realm_str,))

    admin_emails = {admin.email for admin in admins}

    for is_bot, page_title in [(False, 'Humans'), (True, 'Bots')]:
        all_records = list(get_user_activity_records_for_realm(realm_str, is_bot))

        user_records, content = realm_user_summary_table(all_records, admin_emails)
        all_user_records.update(user_records)

        data += [(page_title, content)]

    page_title = 'Clients'
    content = realm_client_table(all_user_records)
    data += [(page_title, content)]

    page_title = 'History'
    content = sent_messages_report(realm_str)
    data += [(page_title, content)]

    realm_link = 'https://stats1.zulip.net:444/render/?from=-7days'
    realm_link += '&target=stats.gauges.staging.users.active.%s.0_16hr' % (realm_str,)

    title = realm_str
    return render_to_response(
        'analytics/activity.html',
        dict(data=data, realm_link=realm_link, title=title),
        request=request
    )

def accounts_register(request):
    # type: (HttpRequest) -> HttpResponse
    key = request.POST['key']
    confirmation = Confirmation.objects.get(confirmation_key=key)
    prereg_user = confirmation.content_object
    email = prereg_user.email
    realm_creation = prereg_user.realm_creation
    try:
        existing_user_profile = get_user_profile_by_email(email)
    except UserProfile.DoesNotExist:
        existing_user_profile = None

    validators.validate_email(email)
    # If OPEN_REALM_CREATION is enabled all user sign ups should go through the
    # special URL with domain name so that REALM can be identified if multiple realms exist
    unique_open_realm = get_unique_open_realm()
    if unique_open_realm is not None:
        realm = unique_open_realm
        domain = realm.domain
    elif prereg_user.referred_by:
        # If someone invited you, you are joining their realm regardless
        # of your e-mail address.
        realm = prereg_user.referred_by.realm
        domain = realm.domain
        if not email_allowed_for_realm(email, realm):
            return render_to_response("zerver/closed_realm.html", {"closed_domain_name": realm.name})
    elif prereg_user.realm:
        # You have a realm set, even though nobody referred you. This
        # happens if you sign up through a special URL for an open
        # realm.
        domain = prereg_user.realm.domain
        realm = get_realm(domain)
    else:
        domain = resolve_email_to_domain(email)
        realm = get_realm(domain)

    if realm and realm.deactivated:
        # The user is trying to register for a deactivated realm. Advise them to
        # contact support.
        return render_to_response("zerver/deactivated.html",
                                  {"deactivated_domain_name": realm.name,
                                   "zulip_administrator": settings.ZULIP_ADMINISTRATOR})

    try:
        if existing_user_profile is not None and existing_user_profile.is_mirror_dummy:
            # Mirror dummy users to be activated must be inactive
            is_inactive(email)
        else:
            # Other users should not already exist at all.
            user_email_is_unique(email)
    except ValidationError:
        return HttpResponseRedirect(reverse('django.contrib.auth.views.login') + '?email=' +
                                    urllib.parse.quote_plus(email))

    name_validated = False
    full_name = None

    if request.POST.get('from_confirmation'):
        try:
            del request.session['authenticated_full_name']
        except KeyError:
            pass
        if realm is not None and realm.is_zephyr_mirror_realm and domain == "mit.edu":
            # for MIT users, we can get an authoritative name from Hesiod
            hesiod_name = compute_mit_user_fullname(email)
            form = RegistrationForm(
                    initial={'full_name': hesiod_name if "@" not in hesiod_name else ""})
            name_validated = True
        elif settings.POPULATE_PROFILE_VIA_LDAP:
            for backend in get_backends():
                if isinstance(backend, LDAPBackend):
                    ldap_attrs = _LDAPUser(backend, backend.django_to_ldap_username(email)).attrs
                    try:
                        ldap_full_name = ldap_attrs[settings.AUTH_LDAP_USER_ATTR_MAP['full_name']][0]
                        request.session['authenticated_full_name'] = ldap_full_name
                        name_validated = True
                        # We don't use initial= here, because if the form is
                        # complete (that is, no additional fields need to be
                        # filled out by the user) we want the form to validate,
                        # so they can be directly registered without having to
                        # go through this interstitial.
                        form = RegistrationForm({'full_name': ldap_full_name})
                        # FIXME: This will result in the user getting
                        # validation errors if they have to enter a password.
                        # Not relevant for ONLY_SSO, though.
                        break
                    except TypeError:
                        # Let the user fill out a name and/or try another backend
                        form = RegistrationForm()
        elif 'full_name' in request.POST:
            form = RegistrationForm(
                initial={'full_name': request.POST.get('full_name')}
            )
        else:
            form = RegistrationForm()
    else:
        postdata = request.POST.copy()
        if name_changes_disabled(realm):
            # If we populate profile information via LDAP and we have a
            # verified name from you on file, use that. Otherwise, fall
#.........这里部分代码省略.........

#.........这里部分代码省略.........
        enter_sends           = user_profile.enter_sends,
        user_id               = user_profile.id,
        left_side_userlist    = register_ret['left_side_userlist'],
        default_language      = register_ret['default_language'],
        default_language_name = get_language_name(register_ret['default_language']),
        language_list_dbl_col = get_language_list_for_templates(register_ret['default_language']),
        language_list         = get_language_list(),
        referrals             = register_ret['referrals'],
        realm_emoji           = register_ret['realm_emoji'],
        needs_tutorial        = needs_tutorial,
        first_in_realm        = first_in_realm,
        prompt_for_invites    = prompt_for_invites,
        notifications_stream  = notifications_stream,
        cross_realm_user_emails = list(get_cross_realm_users()),

        # Stream message notification settings:
        stream_desktop_notifications_enabled =
            user_profile.enable_stream_desktop_notifications,
        stream_sounds_enabled = user_profile.enable_stream_sounds,

        # Private message and @-mention notification settings:
        desktop_notifications_enabled = desktop_notifications_enabled,
        sounds_enabled =
            user_profile.enable_sounds,
        enable_offline_email_notifications =
            user_profile.enable_offline_email_notifications,
        enable_offline_push_notifications =
            user_profile.enable_offline_push_notifications,
        enable_online_push_notifications =
            user_profile.enable_online_push_notifications,
        twenty_four_hour_time = register_ret['twenty_four_hour_time'],

        enable_digest_emails  = user_profile.enable_digest_emails,
        event_queue_id        = register_ret['queue_id'],
        last_event_id         = register_ret['last_event_id'],
        max_message_id        = register_ret['max_message_id'],
        unread_count          = approximate_unread_count(user_profile),
        furthest_read_time    = sent_time_in_epoch_seconds(latest_read),
        save_stacktraces      = settings.SAVE_FRONTEND_STACKTRACES,
        alert_words           = register_ret['alert_words'],
        muted_topics          = register_ret['muted_topics'],
        realm_filters         = register_ret['realm_filters'],
        realm_default_streams = register_ret['realm_default_streams'],
        is_admin              = user_profile.is_realm_admin,
        can_create_streams    = user_profile.can_create_streams(),
        name_changes_disabled = name_changes_disabled(user_profile.realm),
        has_mobile_devices    = num_push_devices_for_user(user_profile) > 0,
        autoscroll_forever = user_profile.autoscroll_forever,
        default_desktop_notifications = user_profile.default_desktop_notifications,
        avatar_url            = avatar_url(user_profile),
        avatar_url_medium     = avatar_url(user_profile, medium=True),
        mandatory_topics      = user_profile.realm.mandatory_topics,
        show_digest_email     = user_profile.realm.show_digest_email,
        presence_disabled     = user_profile.realm.presence_disabled,
        is_zephyr_mirror_realm = user_profile.realm.is_zephyr_mirror_realm,
    )

    if narrow_stream is not None:
        # In narrow_stream context, initial pointer is just latest message
        recipient = get_recipient(Recipient.STREAM, narrow_stream.id)
        try:
            initial_pointer = Message.objects.filter(recipient=recipient).order_by('id').reverse()[0].id
        except IndexError:
            initial_pointer = -1
        page_params["narrow_stream"] = narrow_stream.name
        if narrow_topic is not None:
            page_params["narrow_topic"] = narrow_topic
        page_params["narrow"] = [dict(operator=term[0], operand=term[1]) for term in narrow]
        page_params["max_message_id"] = initial_pointer
        page_params["initial_pointer"] = initial_pointer
        page_params["have_initial_messages"] = (initial_pointer != -1)

    statsd.incr('views.home')
    show_invites = True

    # Some realms only allow admins to invite users
    if user_profile.realm.invite_by_admins_only and not user_profile.is_realm_admin:
        show_invites = False

    product_name = "Zulip"
    page_params['product_name'] = product_name
    request._log_data['extra'] = "[%s]" % (register_ret["queue_id"],)
    response = render_to_response('zerver/index.html',
                                  {'user_profile': user_profile,
                                   'page_params' : simplejson.encoder.JSONEncoderForHTML().encode(page_params),
                                   'nofontface': is_buggy_ua(request.META.get("HTTP_USER_AGENT", "Unspecified")),
                                   'avatar_url': avatar_url(user_profile),
                                   'show_debug':
                                       settings.DEBUG and ('show_debug' in request.GET),
                                   'pipeline': settings.PIPELINE_ENABLED,
                                   'show_invites': show_invites,
                                   'is_admin': user_profile.is_realm_admin,
                                   'show_webathena': user_profile.realm.webathena_enabled,
                                   'enable_feedback': settings.ENABLE_FEEDBACK,
                                   'embedded': narrow_stream is not None,
                                   'product_name': product_name
                                   },
                                  request=request)
    patch_cache_control(response, no_cache=True, no_store=True, must_revalidate=True)
    return response

def stats(request):
    # type: (HttpRequest) -> HttpResponse
    return render_to_response('analytics/stats.html',
                              context=dict(realm_name = request.user.realm.name))