# Enterprise Notification & Task Management System

## Anforderungsanalyse

### Was wird gebaut?
Ein mehrstufiges Notification- und Task-Management-System, das die bestehende Notification-Infrastruktur (Prisma-Model, Bell-Icon, SSE, SMTP) zu einem vollwertigen Enterprise-System ausbaut. Vier Kernfähigkeiten:

1. **Personal Reminders** — User legen eigene Erinnerungen an (Datum/Zeit, optionale Wiederholung, verknüpft mit Entity)
2. **Targeted Notifications** — Admins/Manager senden Notifications an User, Rollen, Projektbeteiligte, OrgUnits
3. **Task Management** — Actionable Tasks mit Status-Tracking, Dashboard-Widget, Entity-Verknüpfung
4. **AI Assistant Integration** — Assistent liest offene Tasks, führt sie aus (Urlaub genehmigen, Allokation erstellen, etc.)

### Bestehende Infrastruktur (wiederverwendbar)
| Komponente | Status | Datei |
|------------|--------|-------|
| `Notification` Prisma-Model | Vorhanden (einfach) | `packages/db/prisma/schema.prisma:1291` |
| Notification tRPC-Router | list, unreadCount, markRead, create | `packages/api/src/router/notification.ts` |
| NotificationBell + Drawer | Bell-Icon mit Badge, Dropdown-Panel | `apps/web/src/components/notifications/NotificationBell.tsx` |
| SSE EventBus (Redis Pub/Sub) | `NOTIFICATION_CREATED` Event | `packages/api/src/sse/event-bus.ts` |
| SMTP Email | `sendEmail()` + SystemSettings | `packages/api/src/lib/email.ts` |
| AI Assistant Tools | `list_notifications`, `mark_notification_read` | `packages/api/src/router/assistant-tools.ts` |
| Dashboard Widget-Registry | 8 Widgets, Pattern etabliert | `apps/web/src/components/dashboard/widgets/` |

### Betroffene Pakete
- **packages/db** — Schema-Erweiterung (Notification -> Task-Felder, neues Broadcast-Model)
- **packages/shared** — Enums, Typen, Zod-Schemas
- **packages/api** — Router-Erweiterung (notification.ts, assistant-tools.ts), Targeting-Logik, Scheduler
- **apps/web** — UI (Task-Widget, Reminder-UI, Notification-Center, Admin-Panel)

---

## Datenmodell-Design

### Erweiterung des bestehenden `Notification`-Models
Das bestehende Model wird um Task-/Reminder-/Targeting-Felder erweitert. Kein neues Model nötig — ein einheitliches System für Notifications + Tasks + Reminders.

```prisma
model Notification {
  id         String    @id @default(cuid())
  userId     String

  // -- Typ & Kategorie --
  category   NotificationCategory @default(NOTIFICATION)  // NEU
  type       String               // z.B. "VACATION_REQUESTED", "TASK_ASSIGNED", "REMINDER"
  priority   NotificationPriority @default(NORMAL)         // NEU

  // -- Inhalt --
  title      String
  body       String?
  entityId   String?
  entityType String?
  link       String?              // NEU: Deep-Link zur relevanten Seite

  // -- Task-Felder (nur fuer category TASK / APPROVAL) --
  taskStatus   TaskStatus?        // NEU: OPEN / IN_PROGRESS / DONE / DISMISSED
  taskAction   String?            // NEU: maschinenlesbare Aktion z.B. "approve_vacation:clxyz123"
  assigneeId   String?            // NEU: wem der Task zugewiesen ist
  dueDate      DateTime?          // NEU: Faelligkeitsdatum
  completedAt  DateTime?          // NEU: Zeitpunkt der Erledigung
  completedBy  String?            // NEU: wer hat erledigt (User-ID, oder "ai-assistant")

  // -- Reminder-Felder --
  remindAt     DateTime?          // NEU: wann soll erinnert werden
  recurrence   String?            // NEU: "daily" | "weekly" | "monthly" | null
  nextRemindAt DateTime?          // NEU: naechster Erinnerungszeitpunkt (berechnet)

  // -- Targeting-Metadaten (fuer Bulk-Sends) --
  sourceId     String?            // NEU: Referenz auf die urspruengliche Broadcast-Nachricht
  senderId     String?            // NEU: wer hat die Notification erstellt (User-ID)
  channel      String  @default("in_app") // NEU: "in_app" | "email" | "both"

  // -- Timestamps --
  readAt     DateTime?
  createdAt  DateTime  @default(now())
  updatedAt  DateTime  @updatedAt       // NEU

  user     User  @relation(fields: [userId], references: [id], onDelete: Cascade)
  assignee User? @relation("taskAssignee", fields: [assigneeId], references: [id])
  sender   User? @relation("notificationSender", fields: [senderId], references: [id])

  @@index([userId, readAt])
  @@index([userId, category, taskStatus])           // NEU: Task-Queries
  @@index([nextRemindAt])                            // NEU: Reminder-Scheduler
  @@index([assigneeId, taskStatus])                  // NEU: Assigned-Tasks
  @@map("notifications")
}

enum NotificationCategory {
  NOTIFICATION  // System/Admin-Benachrichtigung (read-only)
  REMINDER      // Persoenliche Erinnerung (self-created)
  TASK          // Actionable Task mit Status-Tracking
  APPROVAL      // Genehmigungsworkflow (approve/reject)
}

enum NotificationPriority {
  LOW
  NORMAL
  HIGH
  URGENT
}

enum TaskStatus {
  OPEN
  IN_PROGRESS
  DONE
  DISMISSED
}
```

### Broadcast-Model (fuer Gruppen-Notifications)

```prisma
model NotificationBroadcast {
  id            String   @id @default(cuid())
  senderId      String
  title         String
  body          String?
  link          String?
  category      NotificationCategory @default(NOTIFICATION)
  priority      NotificationPriority @default(NORMAL)
  channel       String   @default("in_app")

  // -- Targeting --
  targetType    String   // "user" | "role" | "project" | "orgUnit" | "all"
  targetValue   String?  // Role-Name, Project-ID, OrgUnit-ID, oder null fuer "all"

  // -- Scheduling --
  scheduledAt   DateTime?  // null = sofort
  sentAt        DateTime?
  recipientCount Int @default(0)

  createdAt     DateTime @default(now())

  sender User @relation(fields: [senderId], references: [id])

  @@index([senderId])
  @@index([scheduledAt, sentAt])
  @@map("notification_broadcasts")
}
```

### Task-Action Registry (Enterprise-Pattern)

Maschinenlesbare Aktionen ermoeglichen dem AI-Assistenten, Tasks direkt zu erledigen:

```typescript
// packages/api/src/lib/task-actions.ts
const TASK_ACTION_REGISTRY: Record<string, TaskActionHandler> = {
  "approve_vacation":  { permission: "manageVacations",    execute: ... },
  "reject_vacation":   { permission: "manageVacations",    execute: ... },
  "fill_demand":       { permission: "manageAllocations",  execute: ... },
  "confirm_allocation":{ permission: "manageAllocations",  execute: ... },
  "review_budget":     { permission: "manageProjects",     execute: ... },
};
```

Format: `"action_name:entity_id"` — einfach parsbar, erweiterbar.

---

## Betroffene Pakete & Dateien

| Paket | Dateien | Art |
|-------|---------|-----|
| `packages/db` | `prisma/schema.prisma` | edit — Notification erweitern, Enums, Broadcast-Model |
| `packages/shared` | `src/types/notification.ts` | create — Typen, Enums, Zod-Schemas |
| `packages/shared` | `src/types/enums.ts` | edit — re-exportieren |
| `packages/api` | `src/router/notification.ts` | edit — Task-CRUD, Reminder-CRUD, Broadcast, Targeting |
| `packages/api` | `src/router/index.ts` | edit — ggf. neuen Router registrieren |
| `packages/api` | `src/router/assistant-tools.ts` | edit — neue Tools: list_tasks, execute_task_action, etc. |
| `packages/api` | `src/router/assistant.ts` | edit — TOOL_PERMISSION_MAP + System-Prompt |
| `packages/api` | `src/sse/event-bus.ts` | edit — neue Event-Types |
| `packages/api` | `src/lib/email.ts` | edit — Notification-Email-Templates |
| `packages/api` | `src/lib/notification-targeting.ts` | create — Recipient-Aufloesung |
| `packages/api` | `src/lib/task-actions.ts` | create — Action-Registry |
| `packages/api` | `src/lib/reminder-scheduler.ts` | create — Reminder-Dispatcher |
| `apps/web` | `src/components/notifications/NotificationBell.tsx` | edit — Tabs, Task-Badge |
| `apps/web` | `src/components/notifications/NotificationCenter.tsx` | create — Full-Page |
| `apps/web` | `src/components/notifications/ReminderModal.tsx` | create |
| `apps/web` | `src/components/notifications/BroadcastModal.tsx` | create |
| `apps/web` | `src/components/notifications/TaskCard.tsx` | create |
| `apps/web` | `src/components/dashboard/widgets/TaskWidget.tsx` | create |
| `apps/web` | `src/app/(app)/notifications/page.tsx` | create |
| `apps/web` | `src/app/(app)/admin/notifications/page.tsx` | create |
| `apps/web` | `src/components/layout/AppShell.tsx` | edit — Nav-Links |
| `apps/web` | `src/hooks/useTimelineSSE.ts` | edit — Task-Events |

---

## Task-Liste (atomare Schritte)

### Phase N.1 — Datenmodell & Shared Types

- [ ] **Task 1:** Shared-Typen erstellen -> `packages/shared/src/types/notification.ts`
  - NotificationCategory, NotificationPriority, TaskStatus Enums
  - CreateReminderSchema, CreateBroadcastSchema, UpdateTaskStatusSchema (Zod)
  - TaskAction Interface

- [ ] **Task 2:** Prisma-Schema erweitern -> `packages/db/prisma/schema.prisma`
  - Notification-Model: category, priority, taskStatus, taskAction, assigneeId, dueDate, completedAt, completedBy, remindAt, recurrence, nextRemindAt, sourceId, senderId, channel, link, updatedAt
  - Enums: NotificationCategory, NotificationPriority, TaskStatus
  - Model: NotificationBroadcast
  - User-Relations: taskAssignee, notificationSender, broadcasts
  - Indexes: [userId, category, taskStatus], [nextRemindAt], [assigneeId, taskStatus]

- [ ] **Task 3:** `pnpm db:push` + Dev-Server neu starten

### Phase N.2 — API: Router + Targeting + Scheduler

- [ ] **Task 4:** SSE Event-Types erweitern -> `packages/api/src/sse/event-bus.ts`
  - TASK_ASSIGNED, TASK_COMPLETED, TASK_STATUS_CHANGED, REMINDER_DUE, BROADCAST_SENT
  - Emit-Helper: emitTaskAssigned(), emitTaskCompleted(), emitReminderDue()

- [ ] **Task 5:** Notification-Router erweitern -> `packages/api/src/router/notification.ts`
  - list: Filter nach category, taskStatus, priority
  - listTasks (protectedProcedure): offene Tasks + zugewiesene Tasks
  - taskCounts (protectedProcedure): Counts nach Status
  - updateTaskStatus (protectedProcedure): OPEN->IN_PROGRESS->DONE/DISMISSED
  - createReminder (protectedProcedure): eigene Erinnerung anlegen
  - updateReminder / deleteReminder (protectedProcedure)
  - createBroadcast (managerProcedure): Targeted Notification an Gruppe
  - listBroadcasts (managerProcedure)
  - createTask (managerProcedure): Task fuer User/Gruppe
  - assignTask (managerProcedure): Task zuweisen
  - delete (protectedProcedure): eigene Notifications loeschen

- [ ] **Task 6:** Broadcast-Targeting -> `packages/api/src/lib/notification-targeting.ts` (create)
  - resolveRecipients(targetType, targetValue, db): User-IDs aufloesen
    - "user" -> einzelner User
    - "role" -> alle User mit SystemRole
    - "project" -> Ressourcen mit aktiver Allokation -> verknuepfte User
    - "orgUnit" -> Ressourcen in OrgUnit -> verknuepfte User
    - "all" -> alle aktiven User

- [ ] **Task 7:** Email-Templates -> `packages/api/src/lib/email.ts` (edit)
  - sendNotificationEmail(userId, notification): HTML mit Title, Body, Deep-Link
  - sendTaskEmail(userId, task): Template mit Task-Details + Action-Link

- [ ] **Task 8:** Task-Action-Registry -> `packages/api/src/lib/task-actions.ts` (create)
  - Registry-Pattern: action_name -> { permission, execute(entityId, ctx) }
  - Initiale Actions: approve_vacation, reject_vacation, fill_demand, confirm_allocation

- [ ] **Task 9:** Reminder-Scheduler -> `packages/api/src/lib/reminder-scheduler.ts` (create)
  - Intervall (60s): WHERE nextRemindAt <= NOW()
  - Fuer jeden faelligen Reminder: In-App Notification + optional Email
  - nextRemindAt neu berechnen oder null setzen
  - Catch-up bei Start (ueberfaellige sofort ausloesen)

### Phase N.3 — AI Assistant Integration

- [ ] **Task 10:** Neue Tool-Definitionen -> `packages/api/src/router/assistant-tools.ts`
  - list_tasks: offene Tasks/Approvals mit Filter
  - get_task_detail: Details inkl. verknuepfter Entity
  - update_task_status: Status aendern
  - execute_task_action: maschinenlesbare Aktion ausfuehren
  - create_reminder: Erinnerung anlegen
  - create_task_for_user: Task fuer anderen User (Manager-only)
  - send_broadcast: Notification an Gruppe (Manager-only)

- [ ] **Task 11:** Tool-Executors implementieren -> `packages/api/src/router/assistant-tools.ts`
  - execute_task_action: parst taskAction-String, dispatcht an Action-Registry
  - Permission-Check pro Action (nicht pauschal)

- [ ] **Task 12:** Permission-Map + Prompt -> `packages/api/src/router/assistant.ts`
  - TOOL_PERMISSION_MAP erweitern
  - System-Prompt: Tasks/Reminders als Faehigkeit beschreiben

### Phase N.4 — Frontend

- [ ] **Task 13:** NotificationBell erweitern -> `apps/web/src/components/notifications/NotificationBell.tsx`
  - Zweiter Badge: Task-Count (orange) neben Notification-Count (rot)
  - Tabs: "Alle" | "Tasks" | "Erinnerungen"
  - Task-Items mit Quick-Actions (Done/Dismiss)
  - Link zu "/notifications"

- [ ] **Task 14:** TaskCard-Komponente -> `apps/web/src/components/notifications/TaskCard.tsx` (create)
  - Titel, Body, Due-Date, Priority-Badge, Entity-Link
  - Aktionen: "Start" / "Done" / "Dismiss"
  - Approval-Variante: "Approve" / "Reject"
  - Priority-farbcodiert (URGENT=rot, HIGH=orange, NORMAL=blau, LOW=grau)

- [ ] **Task 15:** ReminderModal -> `apps/web/src/components/notifications/ReminderModal.tsx` (create)
  - Titel, Body, Datum/Uhrzeit, Wiederholung (keine/taeglich/woechentlich/monatlich)
  - Optional: Entity-Verknuepfung (Projekt/Ressource Dropdown)

- [ ] **Task 16:** BroadcastModal -> `apps/web/src/components/notifications/BroadcastModal.tsx` (create)
  - Manager/Admin-only
  - Targeting: Dropdown (Alle/Rolle/Projekt/OrgUnit) + Wert-Auswahl
  - Inhalt: Titel, Body, Priority, Kategorie
  - Kanal: In-App / Email / Beides
  - Scheduling: Sofort / Zeitgesteuert
  - Vorschau: "Wird an X Empfaenger gesendet"

- [ ] **Task 17:** NotificationCenter -> `apps/web/src/app/(app)/notifications/page.tsx` (create)
  - Tabs: Alle | Notifications | Tasks | Reminders | Approvals
  - Filter: Status, Priority, Zeitraum
  - Bulk: "Alle lesen", "Alle erledigt"
  - "Neue Erinnerung" Button

- [ ] **Task 18:** TaskWidget -> `apps/web/src/components/dashboard/widgets/TaskWidget.tsx` (create)
  - Kompakte Liste offener Tasks (max 5-7)
  - Sortiert: Priority -> Due-Date
  - Quick-Actions: Done/Dismiss
  - Footer: "X offene Tasks — Alle anzeigen"
  - In Widget-Registry eintragen

- [ ] **Task 19:** Admin Broadcast-Seite -> `apps/web/src/app/(app)/admin/notifications/page.tsx` (create)
  - Liste gesendeter Broadcasts
  - "Neue Benachrichtigung senden" Button
  - Statistiken: gesendet/gelesen pro Broadcast

- [ ] **Task 20:** AppShell Navigation -> `apps/web/src/components/layout/AppShell.tsx` (edit)
  - "Notifications" fuer alle Rollen
  - "Broadcast" unter Admin (ADMIN/MANAGER)

- [ ] **Task 21:** SSE-Hook -> `apps/web/src/hooks/useTimelineSSE.ts` (edit)
  - Auf TASK_ASSIGNED, TASK_COMPLETED, REMINDER_DUE reagieren
  - React-Query invalidieren: notification.listTasks, notification.taskCounts

### Phase N.5 — Auto-Tasks & Audit

- [ ] **Task 22:** Automatische Task-Erzeugung bei Business-Events
  - vacation.create -> Task "Urlaubsantrag genehmigen" an Manager (APPROVAL)
  - Ueberallokation -> Task "Ueberallokation aufloesen" an Manager
  - Projekt-Deadline < 30 Tage + offene Demands -> Task "Demands besetzen"
  - demand.create -> Task "Demand besetzen" an Manager

- [ ] **Task 23:** Audit-Trail -> `packages/api/src/lib/audit.ts` (create)
  - logTaskAction(taskId, userId, action, details)
  - completedBy: "ai-assistant" fuer AI-erledigte Tasks

---

## Abhaengigkeiten

```
Task 1 (Shared Types) ---+
Task 2 (Schema) ---------+--> Task 3 (db:push)
                          |
Task 3 --> Task 4 (SSE)  |
Task 3 --> Task 5 (Router)|
Task 3 --> Task 6 (Targeting)
Task 3 --> Task 7 (Email) |
Task 3 --> Task 8 (Actions)|
                          |
Task 5 + 6 --> Task 9 (Scheduler)
Task 5 + 8 --> Task 10-12 (AI)
                          |
Task 5 --> Task 13-21 (Frontend, parallel moeglich)
Task 5 --> Task 22 (Auto-Tasks)
```

**Parallel:**
- Task 4 + 5 + 6 + 7 + 8 (verschiedene Dateien)
- Task 13-21 (verschiedene Dateien, 13+14 vor 17+18 empfohlen)

**Sequentiell:**
- Task 1 -> 2 -> 3 (Schema)
- Task 5 -> 10 -> 11 (Router -> Tools -> Executors)

---

## Akzeptanzkriterien

- [ ] `pnpm db:push` ohne Fehler
- [ ] `pnpm --filter @planarchy/api exec tsc --noEmit` — 0 Errors
- [ ] `pnpm --filter @planarchy/web exec tsc --noEmit` — 0 Errors
- [ ] `pnpm test:unit` — alle Tests gruen
- [ ] User kann eigene Erinnerung anlegen (Datum, Wiederholung, Entity)
- [ ] Admin/Manager kann Broadcast an Rolle/Projekt/OrgUnit senden
- [ ] Broadcast erzeugt individuelle Notifications pro Empfaenger
- [ ] Tasks im Dashboard-Widget, sortiert nach Priority + Due-Date
- [ ] Task-Status aenderbar ueber UI (Open -> In Progress -> Done/Dismissed)
- [ ] AI-Assistent kann list_tasks aufrufen und offene Tasks anzeigen
- [ ] AI-Assistent kann execute_task_action ausfuehren (z.B. Urlaub genehmigen)
- [ ] Erledigte Tasks zeigen completedBy (User oder "AI-Assistent")
- [ ] Email-Versand bei channel "email" oder "both"
- [ ] SSE-Events invalidieren React-Query-Caches
- [ ] Reminder-Scheduler erzeugt puenktlich Notifications
- [ ] RBAC: User sehen nur eigene; Manager zugewiesene; Admin Broadcasts

---

## Risiken & offene Fragen

### Risiken
1. **Reminder-Scheduler Zuverlaessigkeit**: Node.js-setInterval kann bei Restart verpassen. Mitigation: Catch-up bei Start (alle ueberfaelligen sofort ausloesen).
2. **Broadcast-Skalierung**: "An alle" mit 500 Usern = 500 Rows. Mitigation: Batch-Insert (createMany).
3. **Task-Action-Sicherheit**: Permissions pro Action pruefen, nicht pauschal. Mitigation: Action-Registry mit Permission pro Handler.
4. **Schema-Migration**: Neue Felder nullable oder mit Default -> bestehende Notifications funktionieren weiter.

### Offene Fragen
1. **Scheduler**: setInterval im SSE-Handler oder separater Worker/Cron? Empfehlung: setInterval (reicht fuer <1000 User)
2. **Task-Delegation**: User duerfen Tasks an andere weiterdelegieren? Empfehlung: Ja (Manager-only)
3. **Retention**: Wie lange alte Notifications aufbewahren? Empfehlung: 90 Tage Auto-Cleanup
4. **Recurring Tasks**: Tasks wiederkehrend wie Reminders? Empfehlung: Phase 2
5. **Approval-Chains**: Mehrstufige Genehmigung? Empfehlung: Phase 2, erstmal einstufig