# Shared

Shared infrastructure, models, contracts, services, and templates used by all five Rose Ash microservices (blog, market, cart, events, federation). Included as a git submodule in each app.

## Structure

```
shared/
  db/
    base.py                 # SQLAlchemy declarative Base
    session.py              # Async session factory (get_session, register_db)
  models/                   # Canonical domain models
    user.py                 # User
    magic_link.py           # MagicLink (auth tokens)
    (domain_event.py removed — table dropped, see migration n4l2i8j0k1)
    kv.py                   # KeyValue (key-value store)
    menu_item.py            # MenuItem (deprecated — use MenuNode)
    menu_node.py            # MenuNode (navigation tree)
    container_relation.py   # ContainerRelation (parent-child content)
    ghost_membership_entities.py  # GhostNewsletter, UserNewsletter
    federation.py           # ActorProfile, APActivity, APFollower, APFollowing,
                            # RemoteActor, APRemotePost, APLocalPost,
                            # APInteraction, APNotification, APAnchor, IPFSPin
  contracts/
    dtos.py                 # Frozen dataclasses for cross-domain data transfer
    protocols.py            # Service protocols (Blog, Calendar, Market, Cart, Federation)
    widgets.py              # Widget types (NavWidget, CardWidget, AccountPageWidget)
  services/
    registry.py             # Typed singleton: services.blog, .calendar, .market, .cart, .federation
    blog_impl.py            # SqlBlogService
    calendar_impl.py        # SqlCalendarService
    market_impl.py          # SqlMarketService
    cart_impl.py            # SqlCartService
    federation_impl.py      # SqlFederationService
    federation_publish.py   # try_publish() — inline AP publication helper
    stubs.py                # No-op stubs for absent domains
    navigation.py           # get_navigation_tree()
    relationships.py        # attach_child, get_children, detach_child
    widget_registry.py      # Widget registry singleton
    widgets/                # Per-domain widget registration
  infrastructure/
    factory.py              # create_base_app() — Quart app factory
    cart_identity.py        # current_cart_identity() (user_id or session_id)
    cart_loader.py          # Cart data loader for context processors
    context.py              # Jinja2 context processors
    jinja_setup.py          # Jinja2 template environment setup
    urls.py                 # URL helpers (blog_url, market_url, etc.)
    user_loader.py          # Load current user from session
    http_utils.py           # HTTP utility functions
  events/
    bus.py                  # emit_activity(), register_activity_handler()
    processor.py            # EventProcessor (polls ap_activities, runs handlers)
    handlers/               # Shared activity handlers
      container_handlers.py #   Navigation rebuild on attach/detach
      login_handlers.py     #   Cart/entry adoption on login
      order_handlers.py     #   Order lifecycle events
      ap_delivery_handler.py #  AP activity delivery to follower inboxes (wildcard)
  utils/
    __init__.py
    calendar_helpers.py     # Calendar period/entry utilities
    http_signatures.py      # RSA keypair generation, HTTP signature signing/verification
    ipfs_client.py          # Async IPFS client (add_bytes, add_json, pin_cid)
    anchoring.py            # Merkle trees + OpenTimestamps Bitcoin anchoring
    webfinger.py            # WebFinger actor resolution
  browser/
    app/                    # Middleware, CSRF, errors, Redis caching, authz, filters
    templates/              # ~300 Jinja2 templates shared across all apps
  containers.py             # ContainerType, container_filter, content_filter helpers
  config.py                 # YAML config loader
  log_config/setup.py       # Logging configuration (JSON formatter)
  static/                   # Shared static assets (CSS, JS, images, FontAwesome)
  editor/                   # Koenig (Ghost) rich text editor build
  alembic/                  # Database migrations
```

## Key Patterns

- **App factory:** All apps call `create_base_app()` which sets up DB sessions, CSRF, error handling, event processing, logging, widget registration, and domain service wiring.
- **Service contracts:** Cross-domain communication via typed Protocols + frozen DTO dataclasses. Apps call `services.calendar.method()`, never import models from other domains.
- **Service registry:** Typed singleton (`services.blog`, `.calendar`, `.market`, `.cart`, `.federation`). Apps wire their own domain + stubs for others via `register_domain_services()`.
- **Activity bus:** `emit_activity()` writes to `ap_activities` table in the caller's transaction. `EventProcessor` polls pending activities and dispatches to registered handlers. Internal events use `visibility="internal"`; federation activities use `visibility="public"` and are delivered to follower inboxes by the wildcard delivery handler.
- **Widget registry:** Domain services register widgets (nav, card, account); templates consume via `widgets.container_nav`, `widgets.container_cards`.
- **Cart identity:** `current_cart_identity()` returns `{"user_id": int|None, "session_id": str|None}` from the request session.

## Alembic Migrations

All apps share one PostgreSQL database. Migrations are managed here and run from the blog app's entrypoint (other apps skip migrations on startup).

```bash
alembic -c shared/alembic.ini upgrade head
```