# 07 — Guest PWA

Goal
- Delight guests with a frictionless, installable photo experience that works offline, respects privacy, and requires no account.

Non-Goals (MVP)
- No comments or chat. No facial recognition. No public profiles. No videos.

Personas
- Guest (attendee) — scans QR, uploads photos, browses and likes.
- Host (tenant) — optionally shares event PIN with guests; moderates via Tenant Admin PWA.

Top Journeys
- Join: Scan QR → Open event → Accept terms → Optional PIN → Land on Gallery.
- Upload: Add photos → Review → Submit → Background upload → Success/Retry.
- Browse: Infinite gallery → Filter (emotion/task) → Open photo → Like/Share → Back.

Core Features
- Event access
  - Access token embedded in QR/link (short-lived, event-scoped); optional PIN challenge.
  - Token refresh if event remains open; server can revoke/close event at any time.
- Offline-first
  - App shell + last N gallery items cached; uploads queued with Background Sync.
  - Conflict-safe retries; user can pause/cancel queued uploads.
- Capture & upload
  - Choose from camera or library; limit file size; show remaining upload cap.
  - Client-side resize to sane max (e.g., 2560px longest edge); EXIF stripped client-side if available.
  - Assign optional emotion/task before submit; default to “Uncategorized”.
  - Upload screen shows quota cards (Photos, Guests) with traffic-light styling and friendly copy when nearing limits.
  - When the backend blocks uploads (limit reached, device blocked, gallery expired), surface localized dialogs with actionable hints.
- Gallery
  - Masonry grid, lazy-load, pull-to-refresh; open photo lightbox with swipe.
  - Like (heart) with optimistic UI; share system sheet (URL to CDN variant).
  - Filters: emotion, featured, mine (local-only tag for items uploaded from this device).
- Public share: host can hand out `https://app.domain/g/\{token\}`; guests see a themed, read-only gallery with per-photo downloads.
  - Banner on gallery header highlights approaching expiry (D-7/D-1) and offers CTA to upload remaining shots before the deadline.
- Safety & abuse controls
  - Rate limits per device and IP; content-length checks; mime/type sniffing.
  - Upload moderation state: pending → approved/hidden; show local status.
- Notification Center
  - Header bell opens a drawer that merges upload queue stats with server-driven notifications (photo highlights, major achievements, host broadcasts, upload failure hints, feedback reminders).
- Data fetched from `/api/v1/events/\{token\}/notifications` with `X-Device-Id` for per-device read receipts; guests can mark items as read/dismissed and follow CTAs (internal routes or external links).
  - Pull-to-refresh + background poll every 90s to keep single-day events reactive without WS infrastructure.
  - When push is available (VAPID keys configured) the drawer surfaces a push toggle, persists subscriptions via `/push-subscriptions`, and the service worker refreshes notifications after every push message.
  - Operations playbook: see `docs/ops/guest-notification-ops.md` for enabling push, required queues, and cron health checks.
- Privacy & legal
  - First run shows legal links (imprint/privacy); consent for push if enabled.
  - No PII stored; guest name is optional free text and not required by default.

Screens
- Splash/Loading: event lookup + token validation; friendly skeleton.
- Slug-based deep links are no longer accepted; guests must enter or scan a join token QR.
- Terms & PIN: legal links, optional PIN input; remember choice per event.
- Gallery: grid of approved photos; toolbar with filter, upload, settings.
- Upload Picker: camera/library, selection preview, emotion/task tagging.
- Upload Queue: items with progress, retry, remove; background sync toggle.
- Photo Lightbox: zoom, like, share; show emotion tags.
- Settings Sheet: Gear-Icon im Header oeffnet eine Sheet-Ansicht mit editierbarem Gastnamen, eingebetteten Rechtsdokumenten (inkl. Zurueck-Navigation) und Cache-Leeren; Theme-Umschalter bleibt im Header.

Wireframes
- See wireframes file at docs/wireframes/guest-pwa.md for low-fidelity layouts and flows.

Core Pages (Pflichtseiten)
- Landing / Einstieg
  - Purpose: Entry to event via QR/PIN; lowest friction.
  - UI: Single input (QR deep link preferred, fallback PIN field) and Join button.
  - States: invalid/expired token, event closed, offline (allow PIN entry and queue attempt).
- Profil-Setup (Name/Avatar)
  - Purpose: Optional personalisation fuer Likes/Statistiken; Name wird lokal im Browser gespeichert.
  - UI: Name-Feld mit Sofort-Validierung; Avatar folgt spaeter.
  - Behavior: Nicht verpflichtend, aber empfohlen; Name kann jederzeit im Settings Sheet angepasst oder geloescht werden.
- Startseite (Home/Feed)
  - Purpose: Central hub; begruesst Gaeste mit ihrem hinterlegten Namen und fuehrt zu den wichtigsten Aktionen.
- Header: Eventtitel plus Live-Kennzahlen (online Gaeste, geloeste Aufgaben); hero-card zeigt "Hey \{Name\}!".
  - Highlights: Drei CTA-Karten fuer Aufgabe ziehen, Direkt-Upload und Galerie sowie ein Button fuer die Upload-Warteschlange.
  - Content: EmotionPicker und GalleryPreview bilden weiterhin den Einstieg in Spielstimmung und aktuelle Fotos.
- Aufgaben-Flow
  - Aufgaben-Picker: Choose random task or emotion mood.
  - Aufgaben-Detail (Karte): Task text, emoji tag, estimated duration, suggested group size; actions: take photo, new task (same mood), change mood.
- Foto-Interaktion
  - Kamera/Upload: Capture or pick; progress + success message on completion; background sync.
  - Galerie/Ãœbersicht: Grid/Feed; filters: Neueste, Beliebt, Meine; Like hearts.
  - Foto-Detailansicht: Fullscreen; likes/reactions; linked task + (optional) uploader name.
- Motivation & Spiel
  - Achievements/Erfolge: Badges (e.g., Erstes Foto, 5 Aufgaben, Beliebtestes Foto); personal progress.
- Optionale Ergänzungen
  - Slideshow/Präsentationsmodus: Auto-rotating gallery for TV/Beamer with likes/task overlay.
  - Onboarding: 1–2 “So funktioniert das Spiel” hints the first time.
  - Event-Abschluss: “Danke fürs Mitmachen”, summary stats, link/QR to online gallery.

Technical Notes
- Installability: PWA manifest + service worker; prompt A2HS on supported browsers.
- Storage: IndexedDB for queue + cache; `CacheStorage` for shell/assets.
- Background Sync: use Background Sync API when available; fallback to retry on app open.
- Accessibility: large tap targets, high contrast, keyboard support, reduced motion.
- i18n: react-i18next with JSON files (`public/lang/\{locale\}/guest.json`); default `de`, fallback `en`; path-based detection (/de/, /en/); RTL not in MVP. Strings for UI (e.g., gallery, upload, tasks) extracted via i18next-scanner; integrate with prefixed routing and middleware.
- Media types: Photos only (no videos) — decision locked for MVP and v1.
- Realtime model: periodic polling (no WebSockets). Home counters every 10s; gallery delta every 30s with exponential backoff when tab hidden or offline.

API Touchpoints
- GET `/api/v1/events/\{token\}` — public event metadata (when open) + theme.
- GET `/api/v1/events/\{token\}/photos` — paginated gallery (approved only).
- POST `/api/v1/events/\{token\}/photos` — signed upload initiation; returns URL + fields.
- POST (S3) — direct upload to object storage; then backend finalize call.
- POST `/api/v1/photos/\{id\}/like` — idempotent like with device token.
- GET `/api/v1/events/\{token\}/notifications` — list guest notifications (requires `X-Device-Id`).
- POST `/api/v1/events/\{token\}/notifications/\{notification\}/read|dismiss` — mark/dismiss notification with device identity.
- POST `/api/v1/events/\{token\}/push-subscriptions` — register a browser push subscription (requires `X-Device-Id` + VAPID public key).
- DELETE `/api/v1/events/\{token\}/push-subscriptions` — revoke a stored push subscription by endpoint.

Limits (MVP defaults)
- Max uploads per device per event: 50
- Max file size (after client resize): 6 MB per photo
- Max resolution: 2560px longest edge per photo

Edge Cases
- Token expired/invalid → Show “Event closed/invalid link”; link to retry.
- No connectivity → Queue actions; show badge; retry policy with backoff.
- Storage full → Offer to clear cache or deselect files.
- Permission denied (camera/photos) → Explain and offer system shortcut.

Decisions
- Videos are not supported (capture/upload strictly photos).

Appendix: Page-to-Feature Mapping
- Landing: Access, validation, join; deep-link handling.
- Profile Setup: Local profile persistence; optional avatar assets.
- Home: Header, info bar, CTAs, feed preview.
- Tasks: Picker (random/emotion), detail card actions.
- Capture/Upload: Camera permissions, client resize, queue handling.
- Gallery: Filters, pagination, lightbox.
- Achievements: Local badges (MVP), server-backed later.
- Slideshow (optional): Read-only, auto-advance, idle-safe.