feat(broadcasts): add admin broadcast page and user opt-out switch

Admin page /admin/broadcasts to write, test and send broadcasts in both
languages; confirms the recipient count before send. History shows the
counts. A new switch in settings lets users opt out of platform mails;
account mails always come. Subject and body are plain text only.

src/App.jsx

@@ -9,6 +9,7 @@ import Dashboard from "./pages/Dashboard.jsx";
 import RegistrationPage from './pages/RegistrationPage.jsx';
 import SettingsPage from './pages/SettingsPage.jsx';
 import AdminHintsPage from './pages/AdminHintsPage.jsx';
+import AdminBroadcastPage from './pages/AdminBroadcastPage.jsx';
 import AdminNewsPage from './pages/AdminNewsPage.jsx';
 import WhatsNewPage from './pages/WhatsNewPage.jsx';
 import WelcomePage from './pages/WelcomePage.jsx';
@@ -82,6 +83,7 @@ function App() {
                             <Route path="/admin/users" element={<AdminUsersPage/>}/>
                             <Route path="/admin/hints" element={<AdminHintsPage/>}/>
                             <Route path="/admin/news" element={<AdminNewsPage/>}/>
+                            <Route path="/admin/broadcasts" element={<AdminBroadcastPage/>}/>
                         </Route>
                         <Route path="/u/:name" element={<PublicProfilePage/>}/>
                         <Route path="/impressum" element={<ImprintPage/>}/>

src/components/AppHeader.jsx

@@ -1,7 +1,7 @@
 import {useEffect, useState} from 'react';
 import {Link, NavLink, useLocation, useNavigate} from 'react-router-dom';
 import {useTranslation} from 'react-i18next';
-import {ChartColumn, Coins, Dices, Eye, Languages, LayoutDashboard, Library, LogOut, Megaphone, Moon, Newspaper, Settings, Shield, Sun} from 'lucide-react';
+import {ChartColumn, Coins, Dices, Eye, Languages, LayoutDashboard, Library, LogOut, Mail, Megaphone, Moon, Newspaper, Settings, Shield, Sun} from 'lucide-react';
 import {toast} from 'sonner';
 
 import {Badge} from '@/components/ui/badge';
@@ -169,6 +169,9 @@ export default function AppHeader({isAuthenticated, onLogout}) {
                                         <DropdownMenuItem asChild>
                                             <Link to="/admin/news"><Newspaper/>{t('NAV.ADMIN_NEWS')}</Link>
                                         </DropdownMenuItem>
+                                        <DropdownMenuItem asChild>
+                                            <Link to="/admin/broadcasts"><Mail/>{t('NAV.ADMIN_BROADCASTS')}</Link>
+                                        </DropdownMenuItem>
                                     </>
                                 )}
                                 {isAdmin && (

src/components/AppHeader.test.jsx

@@ -55,6 +55,7 @@ describe('AppHeader', () => {
 
         expect(await screen.findByText('NAV.ADMIN')).toBeTruthy();
         expect(screen.getByText('NAV.ADMIN_NEWS')).toBeTruthy();
+        expect(screen.getByText('NAV.ADMIN_BROADCASTS')).toBeTruthy();
         expect(screen.getByText('NAV.VIEW_AS.MENU')).toBeTruthy();
         expect(screen.queryByText('NAV.VIEW_AS.BADGE')).toBeNull();
         expect(screen.queryByLabelText('NAV.PENDING_REQUESTS:0')).toBeNull();
@@ -84,6 +85,7 @@ describe('AppHeader', () => {
         openMenu();
         expect(await screen.findByText('NAV.VIEW_AS.MENU')).toBeTruthy();
         expect(screen.queryByText('NAV.ADMIN')).toBeNull();
+        expect(screen.queryByText('NAV.ADMIN_BROADCASTS')).toBeNull();
     });
 
     it('offers nothing of that to a user', async () => {
@@ -96,6 +98,7 @@ describe('AppHeader', () => {
         expect(screen.getByText('NAV.WHATS_NEW')).toBeTruthy();
         expect(screen.queryByText('NAV.ADMIN')).toBeNull();
         expect(screen.queryByText('NAV.ADMIN_NEWS')).toBeNull();
+        expect(screen.queryByText('NAV.ADMIN_BROADCASTS')).toBeNull();
         expect(screen.queryByText('NAV.VIEW_AS.MENU')).toBeNull();
     });
 });

src/components/PreferencesCard.jsx

@@ -11,7 +11,7 @@ import {usePreferences} from '../context/PreferencesContext.jsx';
 import usePersistSettings from '../hooks/usePersistSettings.js';
 import useSaveResponse from '../hooks/useSaveResponse.js';
 import {FAVORITE_PLATFORMS, saveFavoritePlatform} from '../utils/platforms.js';
-import {LANGUAGES, saveSettings} from '../utils/settings.js';
+import {LANGUAGES, savePlatformMails, saveSettings} from '../utils/settings.js';
 
 // Radix Select has no empty value.
 const NO_FAVORITE = 'NONE';
@@ -41,6 +41,13 @@ export default function PreferencesCard() {
         }
     };
 
+    const handlePlatformMailsChange = async (next) => {
+        if (await runSave(() => savePlatformMails(next))) {
+            updateProfile((p) => ({...p, settings: {...p.settings, platformMails: next}}));
+            toast.success(t('SETTINGS.SAVED'));
+        }
+    };
+
     return (
         <Card>
             <CardHeader>
@@ -83,6 +90,14 @@ export default function PreferencesCard() {
                         </SelectContent>
                     </Select>
                 </div>
+                <div className="flex items-center justify-between gap-4">
+                    <div className="space-y-1">
+                        <Label htmlFor="platformMails">{t('SETTINGS.PLATFORM_MAILS')}</Label>
+                        <p className="text-xs text-muted-foreground">{t('SETTINGS.PLATFORM_MAILS_HINT')}</p>
+                    </div>
+                    <Switch id="platformMails" checked={profile?.settings?.platformMails ?? true}
+                            onCheckedChange={handlePlatformMailsChange}/>
+                </div>
             </CardContent>
         </Card>
     );

src/pages/AdminBroadcastPage.jsx

@@ -0,0 +1,322 @@
+import {useCallback, useEffect, useState} from 'react';
+import {useTranslation} from 'react-i18next';
+import {Loader2, Search, Send, X} from 'lucide-react';
+import {toast} from 'sonner';
+
+import {Button} from '@/components/ui/button';
+import {Card, CardContent, CardHeader, CardTitle} from '@/components/ui/card';
+import {
+    Dialog,
+    DialogClose,
+    DialogContent,
+    DialogDescription,
+    DialogFooter,
+    DialogHeader,
+    DialogTitle,
+} from '@/components/ui/dialog';
+import {Input} from '@/components/ui/input';
+import {Label} from '@/components/ui/label';
+import {Textarea} from '@/components/ui/textarea';
+import PageContainer from '../components/PageContainer.jsx';
+import {fetchUsers} from '../utils/admin.js';
+import {fetchBroadcasts, fetchRecipientCount, sendBroadcast, sendTestBroadcast} from '../utils/broadcasts.js';
+import {formatDateTime} from '../utils/format.js';
+import {MAX_BROADCAST_BODY_LENGTH, MAX_BROADCAST_SUBJECT_LENGTH} from '../utils/limits.js';
+
+const emptyForm = () => ({subjectEn: '', subjectDe: '', bodyEn: '', bodyDe: ''});
+const SEARCH_SIZE = 20;
+
+/**
+ * PLATFORM_ADMIN only: write a mail in both languages, send it to all active users or to picked ones, and see the
+ * history with the counts. Auth checks the role.
+ */
+export default function AdminBroadcastPage() {
+    const {t, i18n} = useTranslation();
+    const [entries, setEntries] = useState([]);
+    const [status, setStatus] = useState('loading');
+    const [form, setForm] = useState(emptyForm);
+    const [mode, setMode] = useState('all');
+    const [picked, setPicked] = useState([]);
+    const [query, setQuery] = useState('');
+    const [found, setFound] = useState([]);
+    const [confirm, setConfirm] = useState(null);
+    const [busy, setBusy] = useState(false);
+
+    const load = useCallback(async () => {
+        try {
+            const response = await fetchBroadcasts();
+            if (response.status === 401) return;
+            if (response.status === 403) {
+                setStatus('forbidden');
+                return;
+            }
+            if (!response.ok) {
+                setStatus('error');
+                return;
+            }
+            setEntries((await response.json()).results);
+            setStatus('ready');
+        } catch (err) {
+            console.error('Admin broadcast error:', err);
+            setStatus('error');
+        }
+    }, []);
+
+    useEffect(() => {
+        load();
+    }, [load]);
+
+    const trimmed = () => ({
+        subjectEn: form.subjectEn.trim(),
+        subjectDe: form.subjectDe.trim(),
+        bodyEn: form.bodyEn.trim(),
+        bodyDe: form.bodyDe.trim(),
+    });
+
+    const incomplete = Object.values(trimmed()).some((value) => !value);
+    const userIds = () => (mode === 'all' ? null : picked.map((user) => user.id));
+    const change = (field) => (event) => setForm({...form, [field]: event.target.value});
+
+    const sendTest = async () => {
+        setBusy(true);
+        try {
+            const response = await sendTestBroadcast(trimmed());
+            if (response.status === 401) return;
+            if (response.ok) toast.success(t('ADMIN_BROADCAST.TEST_SENT'));
+            else toast.error(t('ADMIN_BROADCAST.ERROR'));
+        } catch (err) {
+            console.error('Admin broadcast test error:', err);
+            toast.error(t('INFO.ERROR.NETWORK_FAILURE'));
+        } finally {
+            setBusy(false);
+        }
+    };
+
+    const submit = async (event) => {
+        event.preventDefault();
+        setConfirm({count: null});
+        try {
+            const response = await fetchRecipientCount(userIds());
+            if (response.status === 401) return;
+            if (!response.ok) throw new Error(`count ${response.status}`);
+            const {count} = await response.json();
+            setConfirm((current) => (current ? {count} : current));
+        } catch (err) {
+            console.error('Admin broadcast count error:', err);
+            toast.error(t('ADMIN_BROADCAST.ERROR'));
+            setConfirm(null);
+        }
+    };
+
+    const send = async () => {
+        setBusy(true);
+        try {
+            const response = await sendBroadcast({...trimmed(), userIds: userIds()});
+            if (response.status === 401) return;
+            if (response.ok) {
+                const data = await response.json();
+                toast.success(t('ADMIN_BROADCAST.SENT', {count: data.recipientCount}));
+                setConfirm(null);
+                setForm(emptyForm());
+                setPicked([]);
+                setFound([]);
+                await load();
+            } else {
+                toast.error(t(response.status === 409 ? 'ADMIN_BROADCAST.NO_RECIPIENTS' : 'ADMIN_BROADCAST.ERROR'));
+            }
+        } catch (err) {
+            console.error('Admin broadcast send error:', err);
+            toast.error(t('INFO.ERROR.NETWORK_FAILURE'));
+        } finally {
+            setBusy(false);
+        }
+    };
+
+    const search = async () => {
+        try {
+            const response = await fetchUsers(query.trim(), 'ACTIVE', 0, SEARCH_SIZE);
+            if (response.status === 401) return;
+            if (!response.ok) throw new Error(`search ${response.status}`);
+            const {content} = await response.json();
+            setFound(content.filter((user) => !user.blocked && !user.deletedAt));
+        } catch (err) {
+            console.error('Admin broadcast search error:', err);
+            toast.error(t('ADMIN_BROADCAST.ERROR'));
+        }
+    };
+
+    const toggle = (user) => setPicked((current) => (current.some((p) => p.id === user.id)
+        ? current.filter((p) => p.id !== user.id)
+        : [...current, {id: user.id, email: user.email, displayName: user.displayName}]));
+
+    if (status === 'forbidden') {
+        return (
+            <PageContainer className="px-4 py-6 md:px-8">
+                <p className="text-sm text-muted-foreground">{t('ADMIN_BROADCAST.NO_ACCESS')}</p>
+            </PageContainer>
+        );
+    }
+
+    return (
+        <PageContainer className="space-y-4 px-4 py-6 md:px-8">
+            <Card>
+                <CardHeader>
+                    <CardTitle>{t('ADMIN_BROADCAST.NEW')}</CardTitle>
+                </CardHeader>
+                <CardContent>
+                    <form onSubmit={submit} className="space-y-4">
+                        <div className="space-y-2">
+                            <Label htmlFor="broadcastSubjectEn">{t('ADMIN_BROADCAST.SUBJECT_EN')}</Label>
+                            <Input id="broadcastSubjectEn" required maxLength={MAX_BROADCAST_SUBJECT_LENGTH}
+                                   value={form.subjectEn} onChange={change('subjectEn')}/>
+                        </div>
+                        <div className="space-y-2">
+                            <Label htmlFor="broadcastBodyEn">{t('ADMIN_BROADCAST.BODY_EN')}</Label>
+                            <Textarea id="broadcastBodyEn" required maxLength={MAX_BROADCAST_BODY_LENGTH}
+                                      value={form.bodyEn} onChange={change('bodyEn')}/>
+                        </div>
+                        <div className="space-y-2">
+                            <Label htmlFor="broadcastSubjectDe">{t('ADMIN_BROADCAST.SUBJECT_DE')}</Label>
+                            <Input id="broadcastSubjectDe" required maxLength={MAX_BROADCAST_SUBJECT_LENGTH}
+                                   value={form.subjectDe} onChange={change('subjectDe')}/>
+                        </div>
+                        <div className="space-y-2">
+                            <Label htmlFor="broadcastBodyDe">{t('ADMIN_BROADCAST.BODY_DE')}</Label>
+                            <Textarea id="broadcastBodyDe" required maxLength={MAX_BROADCAST_BODY_LENGTH}
+                                      value={form.bodyDe} onChange={change('bodyDe')}/>
+                            <p className="text-xs text-muted-foreground">{t('ADMIN_BROADCAST.TEXT_HELP')}</p>
+                        </div>
+
+                        <div className="space-y-2">
+                            <p className="text-sm font-medium">{t('ADMIN_BROADCAST.RECIPIENTS')}</p>
+                            <div className="flex gap-2">
+                                {['all', 'picked'].map((value) => (
+                                    <Button key={value} type="button" variant={mode === value ? 'default' : 'outline'}
+                                            aria-pressed={mode === value} onClick={() => setMode(value)}>
+                                        {t(`ADMIN_BROADCAST.${value.toUpperCase()}`)}
+                                    </Button>
+                                ))}
+                            </div>
+                        </div>
+
+                        {mode === 'picked' && (
+                            <div className="space-y-3">
+                                <div className="flex gap-2">
+                                    <Input aria-label={t('ADMIN_BROADCAST.SEARCH')} placeholder={t('ADMIN_BROADCAST.SEARCH')}
+                                           value={query} onChange={(event) => setQuery(event.target.value)}
+                                           onKeyDown={(event) => {
+                                               if (event.key === 'Enter') {
+                                                   event.preventDefault();
+                                                   search();
+                                               }
+                                           }}/>
+                                    <Button type="button" variant="outline" size="icon"
+                                            aria-label={t('ADMIN_BROADCAST.SEARCH')} onClick={search}>
+                                        <Search/>
+                                    </Button>
+                                </div>
+                                {found.length > 0 && (
+                                    <ul className="space-y-1">
+                                        {found.map((user) => (
+                                            <li key={user.id}>
+                                                <label className="flex items-center gap-2 text-sm">
+                                                    <input type="checkbox" className="accent-primary"
+                                                           checked={picked.some((p) => p.id === user.id)}
+                                                           onChange={() => toggle(user)}/>
+                                                    {[user.email, user.displayName].filter(Boolean).join(' · ')}
+                                                </label>
+                                            </li>
+                                        ))}
+                                    </ul>
+                                )}
+                                <p className="text-sm text-muted-foreground">
+                                    {t('ADMIN_BROADCAST.PICKED_COUNT', {count: picked.length})}
+                                </p>
+                                {picked.length > 0 && (
+                                    <ul className="flex flex-wrap gap-2">
+                                        {picked.map((user) => (
+                                            <li key={user.id} className="flex items-center gap-1 rounded-md border px-2 py-1 text-sm">
+                                                {user.email}
+                                                <button type="button" aria-label={`${t('ADMIN_BROADCAST.REMOVE')} ${user.email}`}
+                                                        onClick={() => toggle(user)}>
+                                                    <X className="size-3"/>
+                                                </button>
+                                            </li>
+                                        ))}
+                                    </ul>
+                                )}
+                            </div>
+                        )}
+
+                        <div className="flex flex-wrap gap-2">
+                            <Button type="button" variant="outline" disabled={busy || incomplete} onClick={sendTest}>
+                                {t('ADMIN_BROADCAST.TEST')}
+                            </Button>
+                            <Button type="submit" disabled={busy || incomplete || (mode === 'picked' && picked.length === 0)}>
+                                <Send/>{t('ADMIN_BROADCAST.SEND')}
+                            </Button>
+                        </div>
+                    </form>
+                </CardContent>
+            </Card>
+
+            <Card>
+                <CardHeader>
+                    <CardTitle>{t('ADMIN_BROADCAST.LIST')}</CardTitle>
+                </CardHeader>
+                <CardContent>
+                    {status === 'loading' && <Loader2 className="size-5 animate-spin text-muted-foreground"/>}
+                    {status === 'error' && <p className="text-sm text-destructive">{t('ADMIN_BROADCAST.LOAD_ERROR')}</p>}
+                    {status === 'ready' && entries.length === 0 && (
+                        <p className="text-sm text-muted-foreground">{t('ADMIN_BROADCAST.EMPTY')}</p>
+                    )}
+                    {status === 'ready' && entries.length > 0 && (
+                        <ul className="divide-y">
+                            {entries.map((entry) => (
+                                <li key={entry.id} className="space-y-1 py-3">
+                                    <p className="text-xs text-muted-foreground">
+                                        {formatDateTime(entry.createdAt, i18n.language)}
+                                        {' · '}
+                                        {t('ADMIN_BROADCAST.COUNTS', {
+                                            recipients: entry.recipientCount, sent: entry.sentCount, failed: entry.failedCount,
+                                        })}
+                                    </p>
+                                    <p className="font-medium">{entry.subjectEn}</p>
+                                    <p className="font-medium">{entry.subjectDe}</p>
+                                    <p className="whitespace-pre-line break-words text-sm text-muted-foreground">{entry.bodyEn}</p>
+                                    <p className="whitespace-pre-line break-words text-sm text-muted-foreground">{entry.bodyDe}</p>
+                                </li>
+                            ))}
+                        </ul>
+                    )}
+                </CardContent>
+            </Card>
+
+            <Dialog open={!!confirm} onOpenChange={(open) => { if (!open && !busy) setConfirm(null); }}>
+                {confirm && (
+                    <DialogContent>
+                        <DialogHeader>
+                            <DialogTitle>{t('ADMIN_BROADCAST.CONFIRM_TITLE')}</DialogTitle>
+                            <DialogDescription asChild>
+                                <div>
+                                    {confirm.count === null && <Loader2 className="size-5 animate-spin"/>}
+                                    {confirm.count === 0 && t('ADMIN_BROADCAST.NO_RECIPIENTS')}
+                                    {confirm.count > 0 && t('ADMIN_BROADCAST.CONFIRM_TEXT', {count: confirm.count})}
+                                </div>
+                            </DialogDescription>
+                        </DialogHeader>
+                        <DialogFooter>
+                            <DialogClose asChild>
+                                <Button type="button" variant="outline">{t('ADMIN_BROADCAST.CANCEL')}</Button>
+                            </DialogClose>
+                            <Button type="button" disabled={busy || !confirm.count} onClick={send}>
+                                {busy && <Loader2 className="animate-spin"/>}
+                                {t('ADMIN_BROADCAST.CONFIRM')}
+                            </Button>
+                        </DialogFooter>
+                    </DialogContent>
+                )}
+            </Dialog>
+        </PageContainer>
+    );
+}

src/pages/AdminBroadcastPage.test.jsx

@@ -0,0 +1,161 @@
+// @vitest-environment jsdom
+import {afterEach, beforeEach, describe, expect, it, vi} from 'vitest';
+import {cleanup, fireEvent, render, screen, waitFor} from '@testing-library/react';
+import {MemoryRouter} from 'react-router-dom';
+import {toast} from 'sonner';
+import AdminBroadcastPage from './AdminBroadcastPage.jsx';
+import {PreferencesProvider} from '../context/PreferencesContext.jsx';
+import {fetchRoutes, json} from '../test/fetchRoutes.js';
+
+vi.mock('react-i18next', () => import('../test/i18n-mock.js'));
+vi.mock('sonner', () => ({toast: {success: vi.fn(), error: vi.fn()}}));
+
+const ENTRY = {id: 1, subjectEn: 'Maintenance', subjectDe: 'Wartung', bodyEn: 'We pause.', bodyDe: 'Wir pausieren.',
+    createdBy: 1, createdAt: '2026-10-01T10:00:00Z', recipientCount: 5, sentCount: 4, failedCount: 1};
+const USERS = {content: [
+    {id: 7, email: 'ann@example.com', displayName: 'Ann', blocked: false, deletedAt: null},
+    {id: 8, email: 'bob@example.com', displayName: 'Bob', blocked: true, deletedAt: null},
+]};
+
+const withRoutes = (routes) => fetchRoutes({
+    'GET /api/admin/broadcasts': json(200, {results: [ENTRY]}),
+    'GET /api/admin/broadcasts/recipient-count': json(200, {count: 42}),
+    'POST /api/admin/broadcasts': json(201, {recipientCount: 42}),
+    'POST /api/admin/broadcasts/test': json(204),
+    'GET /api/admin/users': json(200, USERS),
+    ...routes,
+});
+const posts = (suffix) => fetch.mock.calls.filter(([url, init]) => init?.method === 'POST' && url.endsWith(suffix));
+const body = (call) => JSON.parse(call[1].body);
+
+const renderPage = () => render(<MemoryRouter><PreferencesProvider><AdminBroadcastPage/></PreferencesProvider></MemoryRouter>);
+
+const fill = () => {
+    fireEvent.change(screen.getByLabelText('ADMIN_BROADCAST.SUBJECT_EN'), {target: {value: ' Hello '}});
+    fireEvent.change(screen.getByLabelText('ADMIN_BROADCAST.BODY_EN'), {target: {value: ' Body en '}});
+    fireEvent.change(screen.getByLabelText('ADMIN_BROADCAST.SUBJECT_DE'), {target: {value: ' Hallo '}});
+    fireEvent.change(screen.getByLabelText('ADMIN_BROADCAST.BODY_DE'), {target: {value: ' Inhalt '}});
+};
+const TRIMMED = {subjectEn: 'Hello', subjectDe: 'Hallo', bodyEn: 'Body en', bodyDe: 'Inhalt'};
+
+describe('AdminBroadcastPage', () => {
+    beforeEach(() => {
+        localStorage.setItem('tbp_session', '1');
+        withRoutes({});
+    });
+
+    afterEach(() => {
+        cleanup();
+        localStorage.clear();
+        vi.clearAllMocks();
+    });
+
+    it('lists the history with the counts', async () => {
+        renderPage();
+
+        expect(await screen.findByText('Maintenance')).toBeTruthy();
+        expect(screen.getByText('Wartung')).toBeTruthy();
+        expect(screen.getByText(/ADMIN_BROADCAST\.COUNTS/)).toBeTruthy();
+    });
+
+    it('sends the trimmed test mail and keeps the form', async () => {
+        renderPage();
+        await screen.findByText('Maintenance');
+        const test = screen.getByText('ADMIN_BROADCAST.TEST').closest('button');
+        expect(test.disabled).toBe(true);
+
+        fill();
+        fireEvent.click(test);
+
+        await waitFor(() => expect(toast.success).toHaveBeenCalledWith('ADMIN_BROADCAST.TEST_SENT'));
+        expect(body(posts('/test')[0])).toEqual(TRIMMED);
+        expect(screen.getByLabelText('ADMIN_BROADCAST.SUBJECT_EN').value).toBe(' Hello ');
+    });
+
+    it('sends to all after the confirmation with the count, then empties the form', async () => {
+        renderPage();
+        await screen.findByText('Maintenance');
+        fill();
+
+        fireEvent.click(screen.getByText('ADMIN_BROADCAST.SEND'));
+
+        expect(await screen.findByText('ADMIN_BROADCAST.CONFIRM_TEXT:42')).toBeTruthy();
+        expect(posts('/broadcasts')).toEqual([]);
+        fireEvent.click(screen.getByText('ADMIN_BROADCAST.CONFIRM'));
+
+        await waitFor(() => expect(toast.success).toHaveBeenCalledWith('ADMIN_BROADCAST.SENT:42'));
+        expect(body(posts('/broadcasts')[0])).toEqual({...TRIMMED, userIds: null});
+        await waitFor(() => expect(screen.getByLabelText('ADMIN_BROADCAST.SUBJECT_EN').value).toBe(''));
+        expect(screen.queryByText('ADMIN_BROADCAST.CONFIRM_TEXT:42')).toBeNull();
+    });
+
+    it('sends to the picked users only and leaves a blocked one out of the list', async () => {
+        renderPage();
+        await screen.findByText('Maintenance');
+        fill();
+        const send = screen.getByText('ADMIN_BROADCAST.SEND').closest('button');
+
+        fireEvent.click(screen.getByText('ADMIN_BROADCAST.PICKED'));
+        expect(send.disabled).toBe(true);
+        fireEvent.change(screen.getByRole('textbox', {name: 'ADMIN_BROADCAST.SEARCH'}), {target: {value: 'a'}});
+        fireEvent.click(screen.getByRole('button', {name: 'ADMIN_BROADCAST.SEARCH'}));
+        const ann = await screen.findByLabelText(/ann@example\.com/);
+        expect(screen.queryByLabelText(/bob@example\.com/)).toBeNull();
+        fireEvent.click(ann);
+
+        expect(screen.getByText('ADMIN_BROADCAST.PICKED_COUNT:1')).toBeTruthy();
+        fireEvent.click(send);
+        await screen.findByText('ADMIN_BROADCAST.CONFIRM_TEXT:42');
+        expect(fetch.mock.calls.some(([url]) => url.includes('/recipient-count?userIds=7'))).toBe(true);
+        fireEvent.click(screen.getByText('ADMIN_BROADCAST.CONFIRM'));
+
+        await waitFor(() => expect(posts('/broadcasts')).toHaveLength(1));
+        expect(body(posts('/broadcasts')[0]).userIds).toEqual([7]);
+    });
+
+    it('cannot send when nobody would get the mail', async () => {
+        withRoutes({'GET /api/admin/broadcasts/recipient-count': json(200, {count: 0})});
+        renderPage();
+        await screen.findByText('Maintenance');
+        fill();
+
+        fireEvent.click(screen.getByText('ADMIN_BROADCAST.SEND'));
+
+        expect(await screen.findByText('ADMIN_BROADCAST.NO_RECIPIENTS')).toBeTruthy();
+        expect(screen.getByText('ADMIN_BROADCAST.CONFIRM').closest('button').disabled).toBe(true);
+    });
+
+    it('keeps the confirmation closed when it was cancelled before the count arrived', async () => {
+        let answer;
+        withRoutes({'GET /api/admin/broadcasts/recipient-count': () => new Promise((resolve) => { answer = resolve; })});
+        renderPage();
+        await screen.findByText('Maintenance');
+        fill();
+
+        fireEvent.click(screen.getByText('ADMIN_BROADCAST.SEND'));
+        fireEvent.click(await screen.findByText('ADMIN_BROADCAST.CANCEL'));
+        await waitFor(() => expect(screen.queryByText('ADMIN_BROADCAST.CANCEL')).toBeNull());
+        answer(json(200, {count: 42}));
+
+        await waitFor(() => expect(fetch.mock.calls.some(([url]) => url.includes('/recipient-count'))).toBe(true));
+        await new Promise((resolve) => setTimeout(resolve, 20));
+        expect(screen.queryByText('ADMIN_BROADCAST.CONFIRM_TEXT:42')).toBeNull();
+    });
+
+    it('does not offer the send while a field is blank', async () => {
+        renderPage();
+        await screen.findByText('Maintenance');
+        fill();
+        fireEvent.change(screen.getByLabelText('ADMIN_BROADCAST.BODY_DE'), {target: {value: '   '}});
+
+        expect(screen.getByText('ADMIN_BROADCAST.SEND').closest('button').disabled).toBe(true);
+    });
+
+    it('shows "no access" to a non-admin', async () => {
+        withRoutes({'GET /api/admin/broadcasts': json(403, {})});
+        renderPage();
+
+        expect(await screen.findByText('ADMIN_BROADCAST.NO_ACCESS')).toBeTruthy();
+        expect(screen.queryByText('ADMIN_BROADCAST.SEND')).toBeNull();
+    });
+});

src/pages/SettingsPage.test.jsx

@@ -31,6 +31,7 @@ const authRoutes = (me) => ({
     'PUT /api/users/settings/appearance': noBody,
     'PUT /api/users/settings/profile-style': noBody,
     'PUT /api/users/settings/favorite-platform': noBody,
+    'PUT /api/users/settings/platform-mails': noBody,
     'GET /api/version': json(404, {}),
 });
 
@@ -247,6 +248,29 @@ describe('SettingsPage favorite platform', () => {
     });
 });
 
+describe('SettingsPage platform mails', () => {
+    beforeEach(() => localStorage.setItem('tbp_session', '1'));
+
+    afterEach(() => {
+        cleanup();
+        localStorage.clear();
+    });
+
+    it('is on by default and saves the opt-out', async () => {
+        toast.success.mockClear();
+        renderPage(profile());
+
+        const mails = await screen.findByRole('switch', {name: 'SETTINGS.PLATFORM_MAILS'});
+        expect(mails.getAttribute('aria-checked')).toBe('true');
+        fireEvent.click(mails);
+
+        await waitFor(() => expect(puts()).toEqual([{enabled: false}]));
+        expect(fetch.mock.calls.find(([, init]) => init?.method === 'PUT')[0]).toContain('/api/users/settings/platform-mails');
+        await waitFor(() => expect(toast.success).toHaveBeenCalledWith('SETTINGS.SAVED'));
+        expect(mails.getAttribute('aria-checked')).toBe('false');
+    });
+});
+
 describe('SettingsPage session', () => {
     beforeEach(() => localStorage.setItem('tbp_session', '1'));
 

src/utils/broadcasts.js

@@ -0,0 +1,30 @@
+import {apiFetch} from './api.js';
+
+const AUTH = () => import.meta.env.VITE_API_URL;
+const JSON_HEADERS = {'Content-Type': 'application/json'};
+
+/**
+ * PLATFORM_ADMIN only (403 otherwise): {results: [{id, subjectEn, subjectDe, bodyEn, bodyDe, createdBy, createdAt,
+ * recipientCount, sentCount, failedCount}]}, newest first.
+ */
+export const fetchBroadcasts = () => apiFetch(`${AUTH()}/api/admin/broadcasts`);
+
+/**
+ * {count}: the active users with platform mails on, among `userIds`; all of them when `userIds` is null.
+ */
+export const fetchRecipientCount = (userIds) =>
+    apiFetch(`${AUTH()}/api/admin/broadcasts/recipient-count${userIds ? `?userIds=${userIds.join(',')}` : ''}`);
+
+/**
+ * `broadcast` is {subjectEn, subjectDe, bodyEn, bodyDe, userIds}. 201 {recipientCount}, 409 NO_RECIPIENTS, or 400 for a
+ * blank or too long field.
+ */
+export const sendBroadcast = (broadcast) =>
+    apiFetch(`${AUTH()}/api/admin/broadcasts`, {method: 'POST', headers: JSON_HEADERS, body: JSON.stringify(broadcast)});
+
+/**
+ * 204: the draft goes to the admin's own address only, in the admin's language.
+ */
+export const sendTestBroadcast = (broadcast) =>
+    apiFetch(`${AUTH()}/api/admin/broadcasts/test`,
+        {method: 'POST', headers: JSON_HEADERS, body: JSON.stringify(broadcast)});

src/utils/limits.js

@@ -33,3 +33,6 @@ export const MAX_HINT_LENGTH = 500;
 // Auth NewsRequest @Size(max = 100) and @Size(max = 2000)
 export const MAX_NEWS_TITLE_LENGTH = 100;
 export const MAX_NEWS_TEXT_LENGTH = 2000;
+// Auth BroadcastRequest @Size(max = 150) and @Size(max = 5000)
+export const MAX_BROADCAST_SUBJECT_LENGTH = 150;
+export const MAX_BROADCAST_BODY_LENGTH = 5000;

src/utils/settings.js

@@ -58,3 +58,11 @@ export const markWelcomeSeen = () =>
         method: 'PUT',
         signal: AbortSignal.timeout(REQUEST_TIMEOUT_MS),
     });
+
+/** PUT on Auth, 204: turns the broadcast mails on or off. The caller handles the response status. */
+export const savePlatformMails = (enabled) =>
+    apiFetch(`${import.meta.env.VITE_API_URL}/api/users/settings/platform-mails`, {
+        method: 'PUT',
+        headers: {'Content-Type': 'application/json'},
+        body: JSON.stringify({enabled}),
+    });