feat(desktop): add CallPreviewPanel — Discord-DM-style join surface

apps/desktop/src/components/CallPreviewPanel.tsx

@@ -0,0 +1,118 @@
+import type { ConversationSummary } from '@chat-app/shared/chat';
+import { useState } from 'react';
+import { useTranslation } from 'react-i18next';
+
+import { useAuth } from '../context/AuthContext';
+import { useCall } from '../context/CallContext';
+import { useCallPresence } from '../lib/useCallPresence';
+import { Avatar } from './Avatar';
+import { PhoneIcon, SpinnerIcon, XIcon } from './icons';
+
+interface Props {
+  conversation: ConversationSummary;
+}
+
+const MAX_TILES = 7;
+
+/**
+ * Discord-DM-style call preview panel. Renders only while peers are in the
+ * conversation's active call and the local user is NOT in it. Provides large
+ * avatar tiles plus a single "Beitreten" call-to-action. Calls are still
+ * STARTED via the topbar phone icon (`ConversationHeader.startCall`); this
+ * component never initiates — only joins.
+ */
+export function CallPreviewPanel({ conversation }: Props) {
+  const { t } = useTranslation(['app']);
+  const { session } = useAuth();
+  const { state, joinActiveCall } = useCall();
+  const presentIds = useCallPresence(conversation.id);
+  const [collapsed, setCollapsed] = useState(false);
+
+  const myId = session?.user.id ?? null;
+  const iAmIn =
+    (state.kind === 'connected' ||
+      state.kind === 'connecting' ||
+      state.kind === 'reconnecting') &&
+    state.conversationId === conversation.id;
+
+  const others = presentIds.filter((u) => u !== myId);
+  if (iAmIn || others.length === 0) return null;
+
+  const visibleTiles = others.slice(0, MAX_TILES);
+  const overflow = Math.max(0, others.length - MAX_TILES);
+  const busy = state.kind !== 'idle';
+
+  const handleJoin = () => {
+    if (busy) return;
+    void joinActiveCall(conversation.id, 'audio');
+  };
+
+  return (
+    <div className="border-b border-line bg-surface-3/70">
+      <div className="flex items-center gap-2 px-5 py-2 text-xs">
+        <PhoneIcon className="h-3.5 w-3.5 text-emerald-500" />
+        <span className="font-semibold uppercase tracking-[0.12em] text-fg-muted">
+          {t('app:call.active_in_conv', {
+            defaultValue: 'Laufender Anruf · {{count}} im Raum',
+            count: others.length,
+          })}
+        </span>
+        <button
+          type="button"
+          onClick={() => setCollapsed((c) => !c)}
+          aria-label={collapsed ? 'Anrufvorschau ausklappen' : 'Anrufvorschau einklappen'}
+          className="ml-auto inline-flex h-6 w-6 cursor-pointer items-center justify-center rounded-md text-fg-muted hover:bg-surface-2 hover:text-fg"
+        >
+          <XIcon className="h-3.5 w-3.5" />
+        </button>
+      </div>
+
+      {!collapsed && (
+        <div className="flex flex-col items-center gap-4 px-5 pb-4 pt-1">
+          <div className="grid w-full max-w-2xl grid-cols-2 gap-3 md:grid-cols-3">
+            {visibleTiles.map((id) => {
+              const member = conversation.members.find((m) => m.userId === id);
+              const name = member?.profile?.displayName ?? '?';
+              return (
+                <div
+                  key={id}
+                  title={name}
+                  className="flex aspect-square flex-col items-center justify-center gap-2 rounded-lg border border-line bg-surface-2 p-3"
+                >
+                  <div className="h-16 w-16 overflow-hidden rounded-full">
+                    <Avatar
+                      url={member?.profile?.avatarUrl ?? null}
+                      displayName={name}
+                      className="h-full w-full text-base"
+                    />
+                  </div>
+                  <span className="line-clamp-1 text-xs font-medium text-fg">{name}</span>
+                </div>
+              );
+            })}
+            {overflow > 0 && (
+              <div className="flex aspect-square flex-col items-center justify-center gap-2 rounded-lg border border-dashed border-line bg-surface-2 p-3 text-fg-muted">
+                <span className="text-xl font-semibold">+{overflow}</span>
+                <span className="text-xs">weitere</span>
+              </div>
+            )}
+          </div>
+
+          <button
+            type="button"
+            onClick={handleJoin}
+            disabled={busy}
+            className="inline-flex w-full max-w-xs cursor-pointer items-center justify-center gap-2 rounded-lg bg-emerald-600 px-4 py-3 text-sm font-semibold text-white transition hover:bg-emerald-500 focus:outline-none focus-visible:ring-2 focus-visible:ring-emerald-400/40 disabled:cursor-not-allowed disabled:opacity-60"
+          >
+            {busy ? (
+              <SpinnerIcon className="h-4 w-4" />
+            ) : (
+              <PhoneIcon className="h-4 w-4" />
+            )}
+            <span>{t('app:call.join', { defaultValue: 'Beitreten' })}</span>
+          </button>
+        </div>
+      )}
+    </div>
+  );
+}