# EventSnap — User Journeys

This document walks through every supported user scenario step-by-step. For a quick "who
can do what" overview, see [FEATURES.md](FEATURES.md). For manual QA, see
[TEST_GUIDE.md](../TEST_GUIDE.md).

---

## 1. First-time guest (the happy path)

1. Guest scans the QR code / opens the event link.
2. Lands on the **join page** (`/join`), sees the event name. A small
   *"Ich habe bereits einen Account"* link is visible below the form for returning users
   — it routes to `/recover`.
3. Types display name → taps **Beitreten**.
4. Server creates the account, generates a 4-digit PIN, stores `bcrypt(PIN)`, signs a
   30-day JWT.
5. A **PIN modal** appears: large monospace digits, a **Kopieren** button, a warning that
   this PIN is the only way to sign in on another device. PIN is also written to
   `localStorage`.
6. Guest taps **Weiter zur Galerie** → lands in the feed (`/feed`).
7. The **first-visit onboarding overlay** appears: six dismissible steps (welcome, upload,
   hashtags, long-press for more actions, hell/dunkel design pick, and PIN — the PIN step
   also points at the **Datenschutzhinweis** in My Account when the admin has set one).
   `localStorage('eventsnap_guide_seen') = 'true'` after dismiss.
8. Guest sees the bottom nav: **🏠 Feed · [📷+ FAB] · 👤 Account**.

## 2. Returning guest, same device

1. App finds a valid JWT in `localStorage`.
2. Redirected straight to `/feed`, no input required.

## 3. Returning guest, new device or cleared storage

1. Guest opens the event link on the new device → join page.
2. Types the **same name** they used before.
3. Server detects the existing account → the join page transforms into a recovery prompt:
   *"„Name" ist bereits vergeben"* with a **PIN input** and an **Anmelden** button, plus
   an **Anderen Namen wählen** escape hatch.
4. Guest types their PIN → `bcrypt.verify` succeeds → new JWT issued for the existing
   `user_id`. PIN is written to `localStorage` on this device too.
5. Wrong PIN: up to 3 attempts. After the third, the account is locked for 15 minutes
   (`pin_locked_until` is set; further attempts return HTTP 429 with a localized message).

## 4. PIN forgotten — Host or Admin resets it

The PIN is visible in **My Account** as long as `localStorage` is intact on at least one
of the user's devices. If lost everywhere, the user asks a Host (or Admin) for a reset.

1. Guest approaches the Host: *"I can't sign in on my new phone."*
2. Host opens the **Host Dashboard → Nutzerverwaltung** and finds the user.
3. Host taps **PIN zurücksetzen** on that row.
4. A confirmation prompt explains what happens; on confirm the server generates a fresh
   4-digit PIN, replaces `recovery_pin_hash` with the new bcrypt, clears any active
   `pin_locked_until`, and returns the new plaintext PIN in the response.
5. A **modal shows the new PIN ONCE** — large, with a copy button. The Host shows the
   screen to the guest or sends it via another channel (SMS, slip of paper, …). Closing
   the modal forgets the plaintext on the operator's device too.
6. Guest goes to `/recover` (or taps "Ich habe bereits einen Account" on `/join`), enters
   their name + the new PIN, signs in, and the PIN is persisted to `localStorage` on
   their device — exactly like a fresh join.

**Permission rules:**
- Host can reset PINs for **guests** only.
- Admin can reset PINs for **hosts and guests** (not other admins; admins use the
  password login).
- Anyone whose PIN was reset retains all their uploads, comments, and likes — only the
  PIN changes.

**If no Host or Admin is reachable**, the guest can still re-join under a new name (a
clean account; their previous uploads remain attributed to the abandoned account, which
the Host can clean up later).

## 5. Posting a photo / video

1. Guest taps the central **📷+ FAB** in the bottom nav.
2. A **bottom sheet** slides up offering **Kamera** (in-app capture) or **Galerie** (file
   picker, multi-select).
3a. **Camera path** — [CameraCapture](../frontend/src/lib/components/CameraCapture.svelte)
    opens the back camera (`facingMode: 'environment'`), with toggle for front camera,
    photo button, and a video-record button using `MediaRecorder`.
3b. **Gallery path** — native picker, multiple selection.
4. **Preview screen** (`/upload`) shows staged files as horizontal thumbnails. The user can:
   - Remove individual files.
   - Type a caption with `#hashtags`.
   - Tap quick-tag chips (derived from the caption) to copy a hashtag into the caption.
5. Taps **Hochladen** → returns immediately to the feed (optimistic UX). The slim progress
   bar above the bottom nav and the red badge on the FAB indicate active uploads.
6. The client uploads files **one at a time** (XHR with progress) from an IndexedDB queue.
7. Each upload triggers a server-side compression job; once the preview is ready the feed
   updates via `upload-processed` SSE — placeholders swap for actual previews.

## 6. Posting under rate limits

1. Hit the per-hour upload limit (default 10 / hour, configurable).
2. Server returns **HTTP 429** with a `Retry-After` header on the next upload attempt.
3. Client parks pending items in **Wartend** state and shows an amber banner:
   *"Upload-Limit erreicht. Wird in Xs automatisch fortgesetzt."*
4. Countdown ticks down. When it reaches 0, the queue resumes automatically.

## 7. Liking and commenting

1. Tap the heart icon on a card or in the lightbox → like is recorded; count increments
   optimistically; server returns the canonical count via `like-update` SSE.
2. Tap the comment icon → opens the lightbox with the comments list.
3. Type a comment → `POST /api/v1/upload/{id}/comment`. Hashtags inside the comment are
   parsed and attached.
4. The user can delete their own comments (trash icon next to them).

## 8. Filtering the gallery

1. Toggle to **grid view** (icon top-right of the feed header).
2. A search bar appears below the header (auto-focused).
3. Type a name or `#hashtag` — autocomplete suggestions are derived **in memory** from the
   loaded uploads.
4. Tap a suggestion → it becomes an **active filter chip** and the search bar clears.
5. Filter logic:
   - Multiple hashtag chips: OR
   - Multiple uploader chips: OR
   - One uploader + one hashtag: AND
6. Open a post → swipe in the lightbox navigates the **filtered set**, not the full feed.

## 9. Hosting the event — moderation

1. Host opens **My Account** → taps **⭐ Host-Dashboard**.
2. **Stats section** — guest count, upload count, lock status, release status.
3. **Event settings** — toggle to lock new uploads (likes / comments / browsing stay open;
   broadcasts `event-closed` SSE so all clients show a "uploads are locked" banner).
4. **Galerie freigeben** — releases the export. Enqueues two export jobs (ZIP + HTML
   viewer). Progress is visible on the Host dashboard *and* in the Admin dashboard's Export
   tab; SSE `export-progress` keeps it live; `export-available` notifies all guests when
   ready. Once released the button is disabled and reads *"Galerie bereits freigegeben"* —
   a second release is a 409. If a keepsake half fails, both dashboards show the reason and
   offer **Erneut versuchen** (rebuild); a ready keepsake can also be rebuilt behind a
   confirm, during which guest downloads are briefly unavailable.
5. **Nutzerverwaltung** — search users; per-user controls:
   - **Sperren** opens a confirmation modal. Banning **always hides** the user's existing
     uploads (a banned user's content is "gone" everywhere) — there is no opt-out. Submitting
     calls `POST /host/users/{id}/ban` (no body).
   - **Entsperren** lifts the ban — and does two further things the confirm sheet now spells
     out, because both are visible to the whole party: it clears `uploads_hidden`, so **all**
     of that user's previously hidden uploads reappear in the gallery, the diashow and the
     export; and it invalidates and rebuilds a released keepsake (`invalidate_and_arm`), so
     every guest's download is unavailable for as long as that takes. A ban does the mirror
     image of both. Same authority boundary as ban: a plain Host may only unban Guests; only
     an Admin may unban a Host.
   - **Host** promotes a guest to host (Hosts and Admins may do this).
   - **Degradieren** — demote a Host back to guest. **Only an Admin may change a Host's
     role.** A plain Host may *not* demote a peer Host: doing so would let them then ban or
     PIN-reset (→ `/recover` account-takeover) that ex-peer, since those guards key off the
     target's *current* role. So the backend rejects it (403) and the button is hidden for
     non-admin Hosts. Nobody may change their own role (self-lockout / self-escalation guard),
     and Admins are un-demotable and un-bannable by anyone. (This tightens an earlier
     "Hosts may demote other Hosts" design — see the F1 security fix.)
   - **Sperren / PIN zurücksetzen** — a plain Host may act on Guests only; an Admin may act on
     Guests + Hosts; nobody may act on an Admin. The buttons are hidden where they'd 403.
     PIN reset generates a new PIN, shows it once in a modal, and revokes the target's
     existing sessions (forcing re-auth with the new PIN). See journey §4.
6. **Deleting content** — Host can delete any upload or comment via the moderation routes
   (`DELETE /host/upload/{id}`, `DELETE /host/comment/{id}`). On mobile this is also
   reachable by long-pressing the content (planned, see §15).

## 10. Banned-guest experience

1. The ban takes effect immediately on the banned user's existing session — the auth
   layer re-reads the live `is_banned` flag on every request rather than trusting the
   JWT, so there's no 30-day token-lifetime window.
2. Their next authenticated *write* request returns HTTP 403 with a clear message
   ("Du bist gesperrt."). Ban enforcement lives on the write handlers and the
   host/admin extractors, not the base auth extractor.
3. They can still browse the read-only feed (and download the export once it's released).
   Their sessions are **not** revoked — this is a read-only ban, not a logout. Their own
   live SSE stream is dropped by the `is_banned` revalidation (no live pushes), but plain
   feed reads still work.
4. They cannot upload, like, or comment; a banned host also loses all host/admin
   actions (including unbanning themselves).
5. Banning **always hides**: the user's existing uploads are filtered out of the feed for
   everyone (`v_feed`, `find_visible_media`, and the export query all enforce
   `is_banned = FALSE`), and a live `user-hidden` SSE event evicts their cards from every
   open feed + the diashow without a reload. A client that was offline/disconnected during
   the live event doesn't miss the eviction: `uploads_hidden_at` is stamped at ban time
   (migration 013) and the reconnect delta (`GET /feed/delta`) returns the banned users in
   `hidden_user_ids`, so the feed and diashow replay the eviction on the next reconnect —
   the projector-missed-the-live-push case is exactly why this exists.

## 11. Admin — instance configuration

1. Admin opens `/admin/login`, types the admin password (compared against
   `ADMIN_PASSWORD_HASH`). Receives a separate 1-day admin JWT (in `sessionStorage`).
2. Admin dashboard has four inner tabs:
   - **Stats**: live counts and disk-usage widget (via `sysinfo`).
   - **Config**: per-file limits (image MB / video MB), rate limits (upload / feed /
     export), quota tolerance, estimated guest count, compression-worker concurrency,
     plus the colour-theme picker, the **Datenschutzhinweis** free-text editor and
     **on/off toggles** for the rate limiters and quotas (see §18). Whitelist on the
     server side rejects unknown keys. Values are read from the `config` table on each
     request — no restart needed.
   - **Export**: the gallery-release control plus the list of export jobs with status
     badges (pending / running / done / failed) and progress bars; refresh button
     re-polls. The release control mirrors the Host dashboard exactly — disabled once
     released (a second tap would only 409), live keepsake status with progress and the
     failure reason, and a **Neu erstellen / Erneut versuchen** rebuild as the recovery
     path for a failed or stale keepsake.
   - **Nutzer**: same user list as Host, with the additional Demote action (admin-only,
     see §9) and PIN-reset on host rows.

## 12. Releasing the export and downloading

1. Host (or Admin) taps **Galerie freigeben** in the dashboard.
2. Server sets `event.export_released_at`, locks uploads, **bumps `event.export_epoch`**, and
   enqueues two background jobs — all in ONE transaction (workers spawn after it commits, so a
   client disconnecting mid-request can never leave the event released with no export to build).

   The **epoch** is the whole generation model (migration 014). It is bumped in the same UPDATE as
   any change to `export_released_at` — release and reopen are its only writers — and each
   `export_job` row carries a copy of the epoch it was enqueued for. An export is downloadable
   **iff** `released AND job.epoch = event.export_epoch AND job.status = 'done'`. Readiness is
   therefore *derived*, never stored: it cannot drift, and a worker whose epoch has been retired
   (by a reopen, a re-release, or a takedown) is inert — anything it writes is simply invisible.
   A reopen retires the current keepsake instantly, which is why a reopened event serves no export
   until the host releases again.
3. ZIP job: streams `Gallery.zip` (`Photos/` + `Videos/`, full-quality originals) directly
   to disk via `async-zip`. Progress updates via `export-progress` SSE.
4. HTML-viewer job: copies the pre-built viewer assets from
   [backend/static/export-viewer/](../backend/static/export-viewer/) (embedded via
   `include_dir!`), generates `data.json` from the database, processes `_thumb`/`_full`
   variants for each upload, and assembles `Memories.zip`.
5. Both jobs complete → server broadcasts `export-available` SSE.
   **Takedowns:** if a host deletes an upload (or a comment) while the gallery is released, the
   epoch is bumped and the keepsake is REGENERATED without it. Otherwise a photo removed on request
   would live on forever in the already-generated archive — the one place it most needs to be gone.
   The download 404s for the few seconds it takes to rebuild, which is the correct answer: serving
   the old archive would serve the deleted photo.
6. Any user opens `/export`:
   - Before release: friendly "Export not yet available" banner.
   - During generation: progress bars per artifact.
   - After completion: two cards (**ZIP-Archiv** and **HTML-Viewer**) with download
     buttons. Tapping the HTML download first shows an in-app guide modal explaining:
     "Entpacke die ZIP, öffne `index.html`". Tapping **Herunterladen** triggers the
     browser download.
7. Downloads are rate-limited **per user** (default 3 / day), keyed on the user id in
   `enforce_export_rate` — deliberately not per IP. At a venue where a hundred guests share
   one NAT'd wifi, a per-IP budget would be exhausted by the third person to tap
   **Herunterladen** and lock everyone else out of their own keepsake.

## 13. Diashow

See [CONCEPT_DIASHOW.md](CONCEPT_DIASHOW.md). Summary of the flow:

1. User taps a **Diashow / Präsentation** action (feed header on tablet/desktop, Account
   on mobile).
2. Navigates to `/diashow` — fullscreen, bottom nav hidden, screen wake-lock acquired.
3. Initial pool fetched from `GET /api/v1/feed`. Slides crossfade every ~6 s.
4. New uploads (`upload-processed` SSE) push to a live queue; the next slide transition
   pops from the live queue first, otherwise from a shuffled queue.
5. `upload-deleted` removes that ID from both queues; if it's the current slide, advance
   immediately.
6. Tap or Escape reveals an overlay (pause, dwell selector, exit).

## 14. Picking a data mode

1. Guest opens **My Account** → scrolls to **Datennutzung**.
2. Two options: **Datensparer (empfohlen)** and **Original**. Saver is the default.
3. Selecting **Original** shows a one-time warning bottom-sheet:
   *"Original-Dateien werden geladen — das kann deine mobile Datennutzung deutlich
   erhöhen. Trotzdem aktivieren?"* with **Abbrechen** / **Aktivieren** buttons.
4. Choice persists in `localStorage` (per-device). The feed, lightbox, and diashow all
   read this flag and load originals instead of compressed previews when Original is on.
5. The viewer (offline HTML export) is unaffected — it already ships with its own pre-
   bundled `_thumb` / `_full` variants.

## 15. Signing out

The wording matters here: nothing is *left* and nothing is deleted. The account, the PIN
and every uploaded photo survive — the user signs back in with name + PIN whenever they
like. ("Event verlassen" read as leaving for good, which the confirmation sheet then
contradicted by saying you can come back.)

1. User opens **My Account** → Konto section. Two separate actions:
   - **Abmelden** — this device only (`DELETE /api/v1/session`).
   - **Auf allen Geräten abmelden** — every session of theirs (`DELETE /api/v1/sessions`),
     for a lost or borrowed phone.
2. Bottom-sheet confirmation naming which of the two it is, with **Abmelden** / **Abbrechen**.
3. Confirming invalidates the session row(s), wipes the local JWT, PIN and the IndexedDB
   upload queue (so the next guest on a shared phone doesn't inherit pending uploads), and
   redirects to the join page. The session-delete call is best-effort: the token is gone
   locally either way, so a network failure never traps the user on the page.

## 16. Reading the Datenschutzhinweis

1. User opens **My Account** → scrolls to **Datenschutzhinweis**.
2. The note is rendered inside a preformatted block (`<pre>`-style: monospace, whitespace
   and newlines preserved exactly as the Admin typed them). No HTML, no markdown — the
   admin's plain text is shown verbatim.
3. The first-visit onboarding overlay carries a one-line reminder of where to find this:
   *"Datenschutzhinweis findest du in deinem Account."*
4. Admin sets / edits the note in **Admin Dashboard → Config → Datenschutzhinweis**: a
   tall textarea with a save button. Saved to a single `config` key.

## 17. Mobile-first gestures (partly shipped)

EventSnap's UI is mobile-first; gestures replace explicit buttons where they're more
ergonomic. Buttons are always present as fallback for desktop and accessibility.

Shipped today: long-press context sheets on posts and comments, and lightbox navigation
(on-screen prev/next controls, ← / → arrow keys, and left/right swipe). The remaining rows
below are still planned.

| Gesture                                   | Action                                                |
|-------------------------------------------|-------------------------------------------------------|
| Long-press on a post (own)                | Bottom sheet → Löschen, Original anzeigen, Teilen     |
| Long-press on a post (other)              | Bottom sheet → Original anzeigen, Teilen, Melden (planned) |
| Long-press on a comment (own)             | Bottom sheet → Löschen                                |
| Long-press on a comment (other)           | Bottom sheet → Kopieren                               |
| Long-press on a user row (Host)           | Bottom sheet → Sperren, Promote/Demote, PIN zurücksetzen |
| Swipe left/right in the lightbox          | Navigate the filtered set                             |
| Swipe down on any bottom sheet            | Dismiss                                               |
| Pull-to-refresh on the feed               | Force a delta-fetch                                   |
| Double-tap on a post                      | Like (heart-burst animation)                          |

On desktop the same actions surface as kebab/⋯ menus, click-able icons in card corners,
and keyboard shortcuts in the lightbox (← → for navigate, Esc to close).

Inspiration: Instagram (double-tap heart, swipe stories), WhatsApp (long-press for
context), Telegram (swipe-to-reply on messages — could inform comment threads if those
land).

## 18. Admin toggles a rate limit or quota off

1. Admin opens **Admin Dashboard → Config**.
2. **Rate-Limits** section: a master switch and per-endpoint switches (upload / feed /
   export / join).
3. Admin flips, e.g., **Upload-Limit aktiv** off. The numeric input for "uploads per hour"
   stays visible but greyed out (still editable for when the toggle goes back on).
4. **Speichern** persists to the `config` table. The next upload request bypasses the
   limiter entirely.
5. **Quoten** section mirrors the pattern: master toggle plus per-area toggles (storage
   bytes / upload count).
6. When the storage-quota toggle is off, the **"Speicher: X / Y"** widget in My Account and
   on the upload screen hides itself (no quota → no number to show). That widget is
   staff-only in any case — guests never see it.

Suggested defaults at deploy time: all toggles **on**, sensible numeric limits.
Toggling off is the explicit escape hatch for testing or trusted internal events.

---

## Edge cases worth knowing

| Case                                                  | Behaviour                                                                       |
|-------------------------------------------------------|---------------------------------------------------------------------------------|
| Browser tab backgrounded for > 5 min                  | SSE closes on `visibilitychange: hidden`; reopens on visible                    |
| Upload finishes while user is on `/account`           | Feed updates anyway — the queue + SSE are global stores                         |
| Event "closed" while files are still in the queue     | Server rejects with a friendly error; client surfaces it in the queue UI        |
| Network drops mid-upload                              | Queue retries the file; retry button available on permanent failure             |
| New device but the PIN was lost                       | Either re-join under a new name, or Host manually re-links (no self-service)    |
| Two guests pick the same name                         | Second one is offered the PIN-recovery form (case-insensitive UNIQUE, mig. 007) |
| Compression fails for a file                          | Server emits `upload-error` SSE; the upload is still listed but marked degraded |
| User deletes their own post (once UI is shipped)      | Soft delete (`deleted_at`); SSE `upload-deleted`; vanishes from feed everywhere |
