# Data Layer

NextGraph-backed local-first data with fallback to local state for demo/disconnected mode.

## Overview

The app has two data modes:
1. **Connected** — NextGraph ORM shapes (P2P, encrypted, local-first)
2. **Disconnected/Demo** — Local React state seeded from `seedData.ts`

All screens use `useFestipodData()` hook regardless of mode.

## NextGraph Stack

```
@ng-org/web          # Browser WASM runtime
@ng-org/orm          # RDF shape-based ORM
@ng-org/shex-orm     # SHEX → TypeScript code generation
@ng-org/alien-deepsignals  # Reactive signals bridge
```

Packages installed from local tarballs in `.ng-tarballs/`.

## SHEX Shapes

`src/shared/shapes/shex/festipodShapes.shex` defines:
- **Event** — title, description, dates, location, themes, participants
- **UserProfile** — name, username, bio, city, visibility
- **Participation** — links event + user, confirmation status

ORM bindings in `src/shared/shapes/orm/`:
- `festipodShapes.schema.ts` — Schema registration
- `festipodShapes.shapeTypes.ts` — Shape type constants
- `festipodShapes.typings.ts` — TypeScript interfaces

Regenerate with `bun run build:orm`.

## Context Providers

### NextGraphContext (`src/shared/context/NextGraphContext.tsx`)
- Connection lifecycle: `disconnected` → `connecting` → `connected` | `error`
- Auto-initializes via `initNg()` from `src/shared/utils/ngSession.ts`
- Provides session with store IDs (private, protected, public)

### FestipodDataContext (`src/shared/context/FestipodDataContext.tsx`)
- Wraps NextGraph shapes with `useShapeWithDefaults()` hook
- CRUD: `createEvent()`, `updateEvent()`, `joinEvent()`, `leaveEvent()`, etc.
- Exposes `useFestipodData()` hook consumed by all screens
- `selectedEventId` state for cross-screen event navigation
- Falls back to seed data when disconnected

## Data Types

`src/shared/data/types.ts`:
- `FpEventData` — id, title, date, location, distance, themes, etc.
- `FpUserData` — id, name, username, bio, city, counts
- `FpParticipationData` — eventId + userId + confirmed
- `FpMeetingPointData` — eventId, location, time, host (local-only)
- `FpFriendshipData` — userId + friendId (local-only)

## Seed Data

`src/shared/data/seedData.ts`:
- 10 users (Marie Dupont = current user, `user-1`)
- Multiple events with dates, locations, themes
- Participations, meeting points, friendships
- `CURRENT_USER_ID = 'user-1'`