# Remote Actor Profile Design

Display full profiles for remote ActivityPub actors: metadata (avatar, bio, banner, profile fields) plus their public posts, fetched in the background via the NATS worker.

## Data Flow

1. User navigates to `/users/@gabrielkaszewski@mastodon.social`
2. Frontend detects `@user@domain` format, calls in parallel:
   - `GET /users/lookup?handle=@user@instance` → enriched profile metadata
   - `GET /federation/actors/{handle}/posts?page=1` → cached posts (empty on first visit)
3. Posts endpoint: looks up interned local `UserId`, queries `feed.user_feed`, **then** publishes `DomainEvent::FetchRemoteActorPosts { actor_ap_url, outbox_url }` fire-and-forget
4. Worker receives event → fetches remote outbox page via HTTP → stores public notes via `ap_repo.accept_note`
5. On next visit/refresh posts are populated

## Domain Changes

### Extend `domain/src/models/remote_actor.rs`

Add fields:
```rust
pub struct RemoteActor {
    pub url: String,
    pub handle: String,
    pub display_name: Option<String>,
    pub inbox_url: String,
    pub shared_inbox_url: Option<String>,
    pub public_key: String,
    pub avatar_url: Option<String>,
    pub last_fetched_at: DateTime<Utc>,
    // new:
    pub bio: Option<String>,
    pub banner_url: Option<String>,
    pub also_known_as: Option<String>,
    pub outbox_url: Option<String>,
    pub attachment: Vec<(String, String)>,  // (name, value)
}
```

### New `domain/src/models/remote_note.rs`

```rust
pub struct RemoteNote {
    pub ap_id: String,
    pub content: String,
    pub published: chrono::DateTime<chrono::Utc>,
    pub sensitive: bool,
    pub content_warning: Option<String>,
}
```

### New `DomainEvent` variant (`domain/src/events.rs`)

```rust
FetchRemoteActorPosts {
    actor_ap_url: String,
    outbox_url: String,
}
```

### New `FederationActionPort` method (`domain/src/ports.rs`)

```rust
async fn fetch_outbox_page(
    &self,
    outbox_url: &str,
    page: u32,
) -> Result<Vec<RemoteNote>, DomainError>;
```

`TestStore` stub returns `Ok(vec![])`.

## activitypub-base Implementation

### `lookup_actor` — populate new `RemoteActor` fields

Map from `DbActor`:
```rust
bio: actor.bio.clone(),
banner_url: actor.banner_url.as_ref().map(|u| u.to_string()),
also_known_as: actor.also_known_as.clone(),
outbox_url: Some(actor.outbox_url.to_string()),
attachment: actor.attachment.iter().map(|f| (f.name.clone(), f.value.clone())).collect(),
```

### `fetch_outbox_page` impl on `ActivityPubService`

```rust
async fn fetch_outbox_page(&self, outbox_url: &str, page: u32) -> Result<Vec<RemoteNote>, DomainError> {
    let url = format!("{}?page={}", outbox_url, page);
    let resp: serde_json::Value = reqwest::Client::new()
        .get(&url)
        .header("Accept", "application/activity+json, application/ld+json")
        .send().await
        .map_err(|e| DomainError::ExternalService(e.to_string()))?
        .json().await
        .map_err(|e| DomainError::ExternalService(e.to_string()))?;

    let items = resp["orderedItems"].as_array().cloned().unwrap_or_default();
    Ok(items.iter().filter_map(|item| {
        // Items are Create activities or Notes directly
        let note = if item["type"].as_str() == Some("Create") {
            &item["object"]
        } else if item["type"].as_str() == Some("Note") {
            item
        } else {
            return None;
        };
        // Only public notes
        let to = note["to"].as_array()?;
        let is_public = to.iter().any(|t| {
            t.as_str() == Some("https://www.w3.org/ns/activitystreams#Public")
        });
        if !is_public { return None; }
        Some(RemoteNote {
            ap_id: note["id"].as_str()?.to_string(),
            content: note["content"].as_str().unwrap_or("").to_string(),
            published: chrono::DateTime::parse_from_rfc3339(
                note["published"].as_str()?
            ).ok()?.with_timezone(&chrono::Utc),
            sensitive: note["sensitive"].as_bool().unwrap_or(false),
            content_warning: note["summary"].as_str().map(|s| s.to_string()),
        })
    }).collect())
}
```

## AppState + Bootstrap

Add `ap_repo: Arc<dyn ActivityPubRepository>` to `presentation/src/state.rs`.

Wire in `bootstrap/src/factory.rs`:
```rust
ap_repo: Arc::new(PgActivityPubRepository::new(pool.clone())),
```

## event-payload

Add to `EventPayload` enum:
```rust
FetchRemoteActorPosts {
    actor_ap_url: String,
    outbox_url: String,
}
```

Add subject (`"fetch_remote_actor_posts"`), mapping from/to `DomainEvent`, and a sample in the uniqueness test.

## REST Endpoint

**`GET /federation/actors/{handle}/posts?page=1`** (new handler in `presentation/src/handlers/federation_actors.rs`):

```rust
pub async fn remote_actor_posts_handler(
    State(s): State<AppState>,
    Path(handle): Path<String>,
    Query(q): Query<PaginationQuery>,
    OptionalAuthUser(viewer): OptionalAuthUser,
) -> Result<Json<serde_json::Value>, ApiError> {
    let actor = s.federation.lookup_actor(&handle).await?;
    let ap_url = url::Url::parse(&actor.url)
        .map_err(|e| ApiError::BadRequest(e.to_string()))?;

    // Get or create interned local UserId for this remote actor
    let author_id = match s.ap_repo.find_remote_actor_id(&ap_url).await? {
        Some(id) => id,
        None => s.ap_repo.intern_remote_actor(&ap_url).await?,
    };

    // Return cached posts
    let page = PageParams { page: q.page(), per_page: q.per_page() };
    let result = s.feed.user_feed(&author_id, &page, viewer.as_ref()).await?;

    // Trigger background fetch (fire and forget)
    if let Some(outbox_url) = &actor.outbox_url {
        let _ = s.events.publish(&DomainEvent::FetchRemoteActorPosts {
            actor_ap_url: actor.url.clone(),
            outbox_url: outbox_url.clone(),
        }).await;
    }

    Ok(Json(serde_json::json!({
        "total": result.total,
        "page": result.page,
        "per_page": result.per_page,
        "items": result.items.iter().map(to_thought_response).collect::<Vec<_>>(),
    })))
}
```

Mount at `GET /federation/actors/{handle}/posts` in `routes.rs`.

Add `pub mod federation_actors;` to `handlers/mod.rs`.

Make `to_thought_response` in `feed.rs` `pub` so `federation_actors.rs` can import it.

## api-types

Extend `RemoteActorResponse`:
```rust
pub struct RemoteActorResponse {
    pub handle: String,
    pub display_name: Option<String>,
    pub avatar_url: Option<String>,
    pub url: String,
    // new:
    pub bio: Option<String>,
    pub banner_url: Option<String>,
    pub also_known_as: Option<String>,
    pub outbox_url: Option<String>,
    pub attachment: Vec<ProfileField>,
}

pub struct ProfileField {
    pub name: String,
    pub value: String,
}
```

Update `lookup_handler` in `users.rs` to populate all new fields.

## Worker

### `FederationEventService` new deps

Add `federation: Arc<dyn FederationActionPort>` and `ap_repo: Arc<dyn ActivityPubRepository>` to `FederationEventService`. Handle the new event:

```rust
DomainEvent::FetchRemoteActorPosts { actor_ap_url, outbox_url } => {
    let notes = match self.federation.fetch_outbox_page(outbox_url, 1).await {
        Ok(n) => n,
        Err(e) => { tracing::warn!("failed to fetch outbox: {e}"); return Ok(()); }
    };
    let actor_url = url::Url::parse(actor_ap_url)
        .map_err(|e| DomainError::ExternalService(e.to_string()))?;
    let author_id = self.ap_repo.intern_remote_actor(&actor_url).await?;
    for note in notes {
        let ap_id = match url::Url::parse(&note.ap_id) {
            Ok(u) => u,
            Err(_) => continue,
        };
        // accept_note is idempotent — ignore duplicate errors
        let _ = self.ap_repo.accept_note(
            &ap_id, &author_id, &note.content, note.published,
            note.sensitive, note.content_warning, "public",
        ).await;
    }
    Ok(())
}
```

Wire new deps in `worker/src/factory.rs`.

## Frontend

### `lib/api.ts`

```typescript
// Enriched RemoteActorSchema (same endpoint, more fields)
export const ProfileFieldSchema = z.object({
  name: z.string(),
  value: z.string(),
});

export const RemoteActorSchema = z.object({
  handle: z.string(),
  displayName: z.string().nullable(),
  avatarUrl: z.string().nullable(),
  url: z.string(),
  bio: z.string().nullable(),
  bannerUrl: z.string().nullable(),
  alsoKnownAs: z.string().nullable(),
  outboxUrl: z.string().nullable(),
  attachment: z.array(ProfileFieldSchema),
});

export const getRemoteActorPosts = (handle: string, page: number, token: string | null) =>
  apiFetch(
    `/federation/actors/${encodeURIComponent(handle)}/posts?page=${page}&per_page=20`,
    {},
    z.object({ total: z.number(), page: z.number(), per_page: z.number(), items: z.array(ThoughtSchema) }),
    token
  );
```

### `app/users/[username]/page.tsx`

Detect `@user@domain` regex. If handle: call `lookupRemoteActor` + `getRemoteActorPosts` in parallel; render `<RemoteUserProfile>`. Otherwise: existing local profile.

### New `components/remote-user-profile.tsx`

Client component showing:
- Banner (`bannerUrl`) — full-width image or placeholder
- Avatar + display name + handle (`@user@instance`)
- Bio (rendered as text)
- Profile fields (`attachment`) — key-value table
- "Also known as" link (if present)
- External profile link button → `url` in new tab
- Follow button (reuse `followUser(handle, token)`)
- Posts list using `ThoughtList` or similar, with empty state "Posts are loading, check back soon"
- Pagination controls