KC-APP/backend/README.md

# KC-App Backend

NestJS API for the KC-App platform (see repo root README + plan for
architecture context).

## Setup

```bash
npm install
cp .env.example .env   # then fill in DATABASE_URL / AUTHENTIK_ISSUER_URL / GUEST_JWT_SECRET / TEAM_JWT_SECRET
npx prisma generate
npx prisma migrate dev --name init   # requires a running PostgreSQL instance
npm run start:dev
```

The API is served under `/api` (see `app.setGlobalPrefix('api')` in
`main.ts`); everything else (`/`, `/app.js`, ...) is served statically from
`../client/web` via `ServeStaticModule`, so the backend doubles as the web
client's host - no separate web server is needed.

## Auth model

- Leitungsteam and Gemeinde Verantwortliche are provisioned in Authentik
  (the "Konfi-Castle-ID"); this API acts as an OIDC **resource server**,
  verifying access tokens against Authentik's JWKS (`AuthentikStrategy`) and
  then resolving local `Membership` rows to determine role + KC/Gemeinde
  scope. Clients perform the actual Authorization Code + PKCE flow against
  Authentik directly.
- Gemeinde Teamer are **local accounts** (no Authentik): a `User` row with a
  `passwordHash` and `kcId` set, `authentikSub` left null. A Gemeinde
  Verantwortliche/r creates them directly or via a `TeamerInvite`
  (shareable group link or per-email invite). Login is `POST /auth/team-login`
  (email + password) or `POST /auth/teamer/register` (redeem an invite
  token); both return a JWT signed with `TEAM_JWT_SECRET` and carrying
  `typ: "team"`. `TeamJwtStrategy` (`AuthGuard('team')`) resolves it to the
  same shape as `AuthentikStrategy`, so guards/controllers treat both alike.
- Guests/Konfis get a temporary local account (first/last name required, no
  Authentik) created via `POST /auth/guest` with a KC invite code, returning
  a JWT signed with `GUEST_JWT_SECRET`.

## Modules implemented so far

- `prisma/` — shared `PrismaClient` provider.
- `auth/` — Authentik resource-server strategy (`AuthGuard('authentik')`),
  guest invite-code login (`AuthGuard('guest')`), and local Gemeinde Teamer
  auth (`AuthGuard('team')`): `POST /auth/team-login` and
  `POST /auth/teamer/register` (invite redemption), bcrypt hashes, tokens
  signed with `TEAM_JWT_SECRET`. `TokenVerificationService` (WS handshake)
  now accepts Authentik, team, or guest tokens.
- `kc/` — KC (event) creation/listing, Leitungsteam-only.
- `gemeinde/` — Gemeinde (congregation) CRUD per KC (`POST /gemeinde`,
  `GET /gemeinde?kcId=`, `GET/PATCH/DELETE /gemeinde/:id`), Leitungsteam-only.
  Gemeinde Verantwortliche/Teamer get their own Gemeinde from their
  `Membership`, not from this endpoint.
- `teamer/` — local Gemeinde Teamer accounts + invites, under
  `/gemeinde/:gemeindeId/...`: `POST/GET teamer`,
  `DELETE teamer/:userId`, `POST/GET teamer-invites`,
  `DELETE teamer-invites/:inviteId`. Callable by Leitungsteam (any Gemeinde)
  or a Verantwortliche/r for their own Gemeinde (enforced in `TeamerService`,
  since `RolesGuard` only scopes by `kcId`). Files/chat read endpoints accept
  `'team'` tokens too, so Teamer see non-Konfi files and chat.
- `wahl/` — Wahl/Workshop administration (Leitungsteam-only), guest
  Teilnehmer submission, Force-Zuteilung overrides, and `ZuteilungService`:
  a faithful port of the WP plugin's `kc_run_zuteilung` (force-assignments →
  up to 3 wish rounds → random fill → consolidation of workshops that stay
  below `minTeilnehmer`), plus CSV export (`GET /wahl/:id/zuteilung/csv`).
- `files/` — Leitungsteam-only upload (`POST /files/:kcId`, multipart) tagged
  with a `FileVisibility` tier; list/download (`GET /files/:kcId`,
  `GET /files/download/:fileId`) accept either an Authentik or a guest token
  and filter by the caller's allowed visibility tiers. Storage is behind a
  `StorageProvider` abstraction: defaults to Nextcloud via WebDAV
  (`WEBDAV_*` env vars), switchable to S3-compatible storage with
  `STORAGE_PROVIDER=s3` (`S3_*` env vars).
- `chat/` — Gemeinde-Gruppenchat, 1:1 Direktnachrichten, Leitungsteam-über-
  greifende Kanäle und Broadcast (Konfis lesen nur). Channel administration
  and message history are plain REST (`ChatController`); real-time send/
  receive is a raw `ws` gateway (`ChatGateway`, path `/chat`) since passport
  guards don't apply to WS upgrades — auth happens once via `?token=` at
  connect time (`TokenVerificationService` tries Authentik JWKS, then falls
  back to a guest token). Access rules live in `ChatService` and are shared
  between the REST and WS entry points.
- `sync/` — replicates mutations between the local (on-site) and cloud
  server. `SyncService.capture()` is called by feature services right after
  a write, appending an entry to the append-only `SyncLogEntry` log tagged
  with this server's `SERVER_ID`. The local server (set `SYNC_ENABLED=true`,
  `SYNC_PEER_URL`) periodically pushes its new entries to the cloud's
  `POST /sync/ingest` and pulls the cloud's via `GET /sync/export`
  (`SyncSchedulerService`, every 30s), both guarded by `SYNC_SHARED_SECRET`
  (`SyncSecretGuard`) rather than user auth. No conflict resolution is
  implemented by design — the local server is the sole source of truth
  while an event is live. `POST /sync/trigger` lets a Leitungsteam member
  force an immediate push+pull. Known gap: only entity metadata is
  replicated; uploaded file bytes only resolve on both sides if local and
  cloud share the same Nextcloud/S3 backend.
- `common/` — `Role` enum, `@Roles()` decorator, `RolesGuard` (KC-scoped,
  Leitungsteam roles are global across all KCs).

All planned backend phases are implemented. `npm test` runs Jest unit tests
(`ZuteilungService`, `TeamAuthService`, `TeamerService`; Prisma mocked).
Remaining work: the Flutter clients (see repo root README), Authentik
provisioning for LT/Verantwortliche, and the first real Prisma migration
(only `schema.prisma` exists so far).