Create chat modal UI & session login for WS auth

Backend: initialize a Django session on token obtain (login) so AuthMiddlewareStack can authenticate WebSocket connections; validate the token serializer and map TokenError -> InvalidToken; call django_logout on logout to destroy the session. Frontend: add a CreateChatModal component (DM/group creation) with user search, selection, validation, API mutation and cache invalidation; wire modal into ChatSidebar and add Czech translations for the new UI strings.

frontend/src/components/social/chat/ChatSidebar.tsx

@@ -7,10 +7,12 @@ import Avatar from "@/components/ui/Avatar";
 import Spinner from "@/components/ui/Spinner";
 import EmptyState from "@/components/ui/EmptyState";
 import IconButton from "@/components/ui/IconButton";
+import CreateChatModal from "./CreateChatModal";
 
 export default function ChatSidebar() {
   const { t } = useTranslation("social");
   const [query, setQuery] = useState("");
+  const [createOpen, setCreateOpen] = useState(false);
 
   const { data, isLoading } = useApiSocialChatsList(
     query ? { search: query } : undefined,
@@ -24,7 +26,11 @@ export default function ChatSidebar() {
         <h2 className="text-sm font-semibold text-brand-text">
           {t("chat.sidebar.title")}
         </h2>
-        <IconButton icon={<FiPlus size={16} />} label={t("chat.sidebar.new")} />
+        <IconButton
+          icon={<FiPlus size={16} />}
+          label={t("chat.sidebar.new")}
+          onClick={() => setCreateOpen(true)}
+        />
       </header>
 
       <div className="relative px-3 py-2">
@@ -86,6 +92,11 @@ export default function ChatSidebar() {
           ))}
         </ul>
       </div>
+
+      <CreateChatModal
+        open={createOpen}
+        onClose={() => setCreateOpen(false)}
+      />
     </aside>
   );
 }

frontend/src/components/social/chat/CreateChatModal.tsx

@@ -0,0 +1,332 @@
+import { useState, useRef, useEffect } from "react";
+import { useNavigate } from "react-router-dom";
+import { useTranslation } from "react-i18next";
+import { FiX, FiSearch, FiCheck } from "react-icons/fi";
+import { useQueryClient } from "@tanstack/react-query";
+import {
+  useApiSocialChatsCreate,
+  getApiSocialChatsListQueryKey,
+} from "@/api/generated/private/chat/chat";
+import { useApiAccountUsersList } from "@/api/generated/private/account/account";
+import type { CustomUser } from "@/api/generated/private/models";
+import { ChatTypeEnum } from "@/api/generated/private/models";
+import Button from "@/components/ui/Button";
+import Input from "@/components/ui/Input";
+import FormErrorBanner from "@/components/ui/FormErrorBanner";
+import Avatar from "@/components/ui/Avatar";
+import Spinner from "@/components/ui/Spinner";
+
+interface Props {
+  open: boolean;
+  onClose: () => void;
+}
+
+type ChatTab = "DM" | "GROUP";
+
+export default function CreateChatModal({ open, onClose }: Props) {
+  const { t } = useTranslation("social");
+  const navigate = useNavigate();
+  const queryClient = useQueryClient();
+
+  const [tab, setTab] = useState<ChatTab>("DM");
+  const [name, setName] = useState("");
+  const [userQuery, setUserQuery] = useState("");
+  const [debouncedQuery, setDebouncedQuery] = useState("");
+  const [selectedUsers, setSelectedUsers] = useState<CustomUser[]>([]);
+  const [showDropdown, setShowDropdown] = useState(false);
+  const [error, setError] = useState<string | null>(null);
+
+  const searchRef = useRef<HTMLDivElement>(null);
+
+  // Debounce the user search
+  useEffect(() => {
+    const t = setTimeout(() => setDebouncedQuery(userQuery.trim()), 300);
+    return () => clearTimeout(t);
+  }, [userQuery]);
+
+  // Close dropdown on outside click
+  useEffect(() => {
+    function handler(e: MouseEvent) {
+      if (searchRef.current && !searchRef.current.contains(e.target as Node)) {
+        setShowDropdown(false);
+      }
+    }
+    document.addEventListener("mousedown", handler);
+    return () => document.removeEventListener("mousedown", handler);
+  }, []);
+
+  // Reset form on tab change
+  const switchTab = (t: ChatTab) => {
+    setTab(t);
+    setName("");
+    setUserQuery("");
+    setDebouncedQuery("");
+    setSelectedUsers([]);
+    setError(null);
+  };
+
+  // User search query
+  const { data: usersData, isLoading: usersLoading } = useApiAccountUsersList(
+    debouncedQuery.length >= 2 ? { username: debouncedQuery } : undefined,
+    { query: { enabled: debouncedQuery.length >= 2 } },
+  );
+
+  const users = usersData?.results ?? [];
+  const filteredUsers = users.filter(
+    (u) => !selectedUsers.some((s) => s.id === u.id),
+  );
+
+  // Create mutation
+  const { mutate: createChat, isPending } = useApiSocialChatsCreate({
+    mutation: {
+      onSuccess: async (chat) => {
+        await queryClient.invalidateQueries({
+          queryKey: getApiSocialChatsListQueryKey(),
+        });
+        onClose();
+        navigate(`/social/chats/${chat.id}`);
+      },
+      onError: (err: unknown) => {
+        const msg =
+          (err as { response?: { data?: { detail?: string; name?: string[] } } })
+            ?.response?.data?.detail ??
+          (err as { response?: { data?: { name?: string[] } } })?.response?.data
+            ?.name?.[0] ??
+          t("chat.create.error");
+        setError(msg);
+      },
+    },
+  });
+
+  function toggleUser(user: CustomUser) {
+    setSelectedUsers((prev) =>
+      prev.some((u) => u.id === user.id)
+        ? prev.filter((u) => u.id !== user.id)
+        : [...prev, user],
+    );
+    setUserQuery("");
+    setShowDropdown(false);
+  }
+
+  function handleSubmit(e: React.FormEvent) {
+    e.preventDefault();
+    setError(null);
+
+    if (tab === "GROUP" && !name.trim()) {
+      setError(t("chat.create.nameRequired"));
+      return;
+    }
+    if (tab === "DM" && selectedUsers.length === 0) {
+      setError(t("chat.create.recipientRequired"));
+      return;
+    }
+
+    createChat({
+      data: {
+        chat_type: tab === "DM" ? ChatTypeEnum.DM : ChatTypeEnum.GROUP,
+        name: tab === "GROUP" ? name.trim() : undefined,
+        members: selectedUsers.map((u) => u.id),
+      },
+    });
+  }
+
+  // Close on Escape
+  useEffect(() => {
+    if (!open) return;
+    const handler = (e: KeyboardEvent) => {
+      if (e.key === "Escape") onClose();
+    };
+    window.addEventListener("keydown", handler);
+    return () => window.removeEventListener("keydown", handler);
+  }, [open, onClose]);
+
+  if (!open) return null;
+
+  return (
+    <div
+      className="fixed inset-0 z-50 flex items-center justify-center p-4"
+      role="dialog"
+      aria-modal="true"
+      aria-label={t("chat.create.title")}
+    >
+      {/* Backdrop */}
+      <div
+        className="absolute inset-0 bg-black/60 backdrop-blur-sm"
+        onClick={onClose}
+      />
+
+      {/* Dialog */}
+      <div className="relative z-10 w-full max-w-md rounded-2xl border border-brand-lines/20 bg-brand-bgLight shadow-2xl">
+        {/* Header */}
+        <div className="flex items-center justify-between border-b border-brand-lines/15 px-5 py-4">
+          <h2 className="text-base font-semibold text-brand-text">
+            {t("chat.create.title")}
+          </h2>
+          <button
+            type="button"
+            onClick={onClose}
+            className="inline-flex h-7 w-7 items-center justify-center rounded-full text-brand-text/60 hover:bg-brand-lines/15 hover:text-brand-text transition-colors"
+            aria-label={t("chat.create.close")}
+          >
+            <FiX size={16} />
+          </button>
+        </div>
+
+        {/* Tab switcher */}
+        <div className="flex border-b border-brand-lines/15 px-5 pt-4 gap-1">
+          {(["DM", "GROUP"] as ChatTab[]).map((type) => (
+            <button
+              key={type}
+              type="button"
+              onClick={() => switchTab(type)}
+              className={[
+                "px-4 py-2 text-sm font-medium rounded-t-lg transition-colors",
+                tab === type
+                  ? "border-b-2 border-brand-accent text-brand-accent"
+                  : "text-brand-text/60 hover:text-brand-text",
+              ].join(" ")}
+            >
+              {type === "DM"
+                ? t("chat.create.tabDM")
+                : t("chat.create.tabGroup")}
+            </button>
+          ))}
+        </div>
+
+        {/* Form */}
+        <form onSubmit={handleSubmit} className="px-5 py-5 space-y-4">
+          {/* Group name */}
+          {tab === "GROUP" && (
+            <Input
+              label={t("chat.create.nameLabel")}
+              placeholder={t("chat.create.namePlaceholder")}
+              value={name}
+              onChange={(e) => setName(e.target.value)}
+              maxLength={255}
+              autoFocus
+            />
+          )}
+
+          {/* User search */}
+          <div ref={searchRef} className="relative">
+            <label className="mb-1.5 block text-sm font-medium text-brand-text/90">
+              {tab === "DM"
+                ? t("chat.create.recipientLabel")
+                : t("chat.create.membersLabel")}
+            </label>
+
+            {/* Selected user chips */}
+            {selectedUsers.length > 0 && (
+              <div className="mb-2 flex flex-wrap gap-1.5">
+                {selectedUsers.map((u) => (
+                  <span
+                    key={u.id}
+                    className="inline-flex items-center gap-1.5 rounded-full bg-brand-accent/15 border border-brand-accent/30 px-2.5 py-1 text-xs text-brand-accent"
+                  >
+                    {u.username}
+                    <button
+                      type="button"
+                      onClick={() => toggleUser(u)}
+                      className="hover:text-brand-text transition-colors"
+                      aria-label={`Remove ${u.username}`}
+                    >
+                      <FiX size={11} />
+                    </button>
+                  </span>
+                ))}
+              </div>
+            )}
+
+            {/* Search input */}
+            {(tab === "GROUP" || selectedUsers.length === 0) && (
+              <div className="relative">
+                <FiSearch
+                  className="pointer-events-none absolute left-3 top-1/2 -translate-y-1/2 text-brand-text/40"
+                  size={14}
+                />
+                <input
+                  value={userQuery}
+                  onChange={(e) => {
+                    setUserQuery(e.target.value);
+                    setShowDropdown(true);
+                  }}
+                  onFocus={() => userQuery.length >= 2 && setShowDropdown(true)}
+                  placeholder={t("chat.create.searchPlaceholder")}
+                  className="w-full rounded-xl border border-brand-lines/25 bg-brand-bgLight/40 py-2.5 pl-8 pr-3 text-sm text-brand-text placeholder:text-brand-text/40 focus:border-brand-accent focus:outline-none focus:ring-2 focus:ring-brand-accent/30"
+                />
+              </div>
+            )}
+
+            {/* Dropdown */}
+            {showDropdown && debouncedQuery.length >= 2 && (
+              <div className="absolute left-0 right-0 top-full z-20 mt-1 max-h-52 overflow-y-auto rounded-xl border border-brand-lines/20 bg-brand-bg shadow-xl">
+                {usersLoading && (
+                  <div className="flex justify-center py-4">
+                    <Spinner size={18} />
+                  </div>
+                )}
+                {!usersLoading && filteredUsers.length === 0 && (
+                  <p className="px-4 py-3 text-sm text-brand-text/50">
+                    {t("chat.create.noUsers")}
+                  </p>
+                )}
+                {filteredUsers.map((user) => (
+                  <button
+                    key={user.id}
+                    type="button"
+                    onClick={() => toggleUser(user)}
+                    className="flex w-full items-center gap-3 px-4 py-2.5 text-left hover:bg-brand-lines/10 transition-colors"
+                  >
+                    <Avatar
+                      name={user.username}
+                      src={user.avatar ?? undefined}
+                      size={28}
+                    />
+                    <div className="min-w-0 flex-1">
+                      <div className="text-sm font-medium text-brand-text">
+                        {user.username}
+                      </div>
+                      {(user.first_name || user.last_name) && (
+                        <div className="truncate text-xs text-brand-text/50">
+                          {[user.first_name, user.last_name]
+                            .filter(Boolean)
+                            .join(" ")}
+                        </div>
+                      )}
+                    </div>
+                    {selectedUsers.some((s) => s.id === user.id) && (
+                      <FiCheck size={14} className="shrink-0 text-brand-accent" />
+                    )}
+                  </button>
+                ))}
+              </div>
+            )}
+          </div>
+
+          <FormErrorBanner message={error} />
+
+          {/* Footer */}
+          <div className="flex items-center justify-end gap-2 pt-1">
+            <Button
+              type="button"
+              variant="ghost"
+              size="sm"
+              onClick={onClose}
+              disabled={isPending}
+            >
+              {t("chat.create.cancel")}
+            </Button>
+            <Button
+              type="submit"
+              variant="primary"
+              size="sm"
+              loading={isPending}
+            >
+              {t("chat.create.submit")}
+            </Button>
+          </div>
+        </form>
+      </div>
+    </div>
+  );
+}

frontend/src/i18n/locales/cs/social.json

@@ -61,6 +61,23 @@
       "empty": "Zatím žádné konverzace.",
       "new": "Nová konverzace"
     },
+    "create": {
+      "title": "Nová konverzace",
+      "close": "Zavřít",
+      "tabDM": "Přímá zpráva",
+      "tabGroup": "Skupinový chat",
+      "nameLabel": "Název skupiny",
+      "namePlaceholder": "Zadejte název chatu...",
+      "nameRequired": "Název skupiny je povinný.",
+      "recipientLabel": "Příjemce",
+      "membersLabel": "Přidat členy",
+      "searchPlaceholder": "Hledat uživatele...",
+      "noUsers": "Žádní uživatelé nenalezeni.",
+      "recipientRequired": "Vyberte příjemce.",
+      "cancel": "Zrušit",
+      "submit": "Vytvořit",
+      "error": "Nepodařilo se vytvořit konverzaci."
+    },
     "room": {
       "selectChat": "Vyberte konverzaci nalevo",
       "typing": "{{user}} píše...",