feat: add followers/following collection json methods

.gitignore

@@ -0,0 +1,2 @@
+/target
+Cargo.lock

src/lib.rs

@@ -1 +1,28 @@
-// placeholder — filled in Task 4
+pub mod activities;
+pub mod actor_handler;
+pub mod actors;
+pub mod content;
+pub mod data;
+pub mod error;
+pub mod federation;
+pub mod followers_handler;
+pub mod inbox;
+pub mod nodeinfo;
+pub mod outbox;
+pub mod repository;
+pub mod service;
+pub(crate) mod urls;
+pub mod user;
+pub mod webfinger;
+
+pub use urls::AS_PUBLIC;
+pub use activitypub_federation::kinds::object::NoteType;
+pub use content::ApObjectHandler;
+pub use data::FederationData;
+pub use error::Error;
+pub use federation::ApFederationConfig;
+pub use repository::{
+    BlockedDomain, FederationRepository, Follower, FollowerStatus, FollowingStatus, RemoteActor,
+};
+pub use service::ActivityPubService;
+pub use user::{ApProfileField, ApUser, ApUserRepository};

src/service.rs

@@ -32,6 +32,7 @@ const DELIVERY_INITIAL_DELAY_SECS: u64 = 1;
 const HTTP_FETCH_TIMEOUT_SECS: u64 = 30;
 const BATCH_FETCH_SLEEP_MS: u64 = 100;
 
+#[allow(dead_code)]
 fn content_to_html(text: &str) -> String {
     let escaped = text
         .replace('&', "&")
@@ -172,6 +173,10 @@ impl ActivityPubService {
         self.federation_config.to_request_data()
     }
 
+    pub fn base_url(&self) -> &str {
+        &self.base_url
+    }
+
     /// Returns `(local_actor, deduplicated_inboxes)` for all accepted followers,
     /// excluding blocked actors and blocked domains.
     /// Returns `None` if there are no eligible followers.
@@ -219,6 +224,98 @@ impl ActivityPubService {
         Ok(Some((local_actor, collect_inboxes(&accepted))))
     }
 
+    /// Build an OrderedCollection or OrderedCollectionPage JSON for the local
+    /// user's followers list.  Pass `page = None` for the root collection.
+    pub async fn followers_collection_json(
+        &self,
+        user_id: uuid::Uuid,
+        page: Option<u32>,
+    ) -> anyhow::Result<String> {
+        const AP_CONTEXT: &str = "https://www.w3.org/ns/activitystreams";
+        const PAGE_SIZE: usize = 20;
+        let data = self.federation_config.to_request_data();
+        let collection_id = format!("{}/users/{}/followers", self.base_url, user_id);
+        let total = data.federation_repo.count_followers(user_id).await?;
+        let obj = if let Some(p) = page {
+            let p = p.max(1);
+            let offset = (p.saturating_sub(1) as usize) * PAGE_SIZE;
+            let followers = data
+                .federation_repo
+                .get_followers_page(user_id, offset as u32, PAGE_SIZE)
+                .await?;
+            let has_next = offset + followers.len() < total;
+            let items: Vec<String> = followers.into_iter().map(|f| f.actor.url).collect();
+            let mut obj = serde_json::json!({
+                "@context": AP_CONTEXT,
+                "type": "OrderedCollectionPage",
+                "id": format!("{}?page={}", collection_id, p),
+                "partOf": collection_id,
+                "totalItems": total,
+                "orderedItems": items,
+            });
+            if has_next {
+                obj["next"] =
+                    serde_json::json!(format!("{}?page={}", collection_id, p + 1));
+            }
+            obj
+        } else {
+            serde_json::json!({
+                "@context": AP_CONTEXT,
+                "type": "OrderedCollection",
+                "id": collection_id,
+                "totalItems": total,
+                "first": format!("{}?page=1", collection_id),
+            })
+        };
+        Ok(serde_json::to_string(&obj)?)
+    }
+
+    /// Build an OrderedCollection or OrderedCollectionPage JSON for the local
+    /// user's following list.  Pass `page = None` for the root collection.
+    pub async fn following_collection_json(
+        &self,
+        user_id: uuid::Uuid,
+        page: Option<u32>,
+    ) -> anyhow::Result<String> {
+        const AP_CONTEXT: &str = "https://www.w3.org/ns/activitystreams";
+        const PAGE_SIZE: usize = 20;
+        let data = self.federation_config.to_request_data();
+        let collection_id = format!("{}/users/{}/following", self.base_url, user_id);
+        let total = data.federation_repo.count_following(user_id).await?;
+        let obj = if let Some(p) = page {
+            let p = p.max(1);
+            let offset = (p.saturating_sub(1) as usize) * PAGE_SIZE;
+            let following = data
+                .federation_repo
+                .get_following_page(user_id, offset as u32, PAGE_SIZE)
+                .await?;
+            let has_next = offset + following.len() < total;
+            let items: Vec<String> = following.into_iter().map(|a| a.url).collect();
+            let mut obj = serde_json::json!({
+                "@context": AP_CONTEXT,
+                "type": "OrderedCollectionPage",
+                "id": format!("{}?page={}", collection_id, p),
+                "partOf": collection_id,
+                "totalItems": total,
+                "orderedItems": items,
+            });
+            if has_next {
+                obj["next"] =
+                    serde_json::json!(format!("{}?page={}", collection_id, p + 1));
+            }
+            obj
+        } else {
+            serde_json::json!({
+                "@context": AP_CONTEXT,
+                "type": "OrderedCollection",
+                "id": collection_id,
+                "totalItems": total,
+                "first": format!("{}?page=1", collection_id),
+            })
+        };
+        Ok(serde_json::to_string(&obj)?)
+    }
+
     pub async fn actor_json(&self, user_id_str: &str) -> anyhow::Result<String> {
         use activitypub_federation::traits::Object;
         let uuid = uuid::Uuid::parse_str(user_id_str)?;
@@ -913,6 +1010,92 @@ impl ActivityPubService {
         Ok(())
     }
 
+    /// Fan out a Create(Note) activity to all accepted followers.
+    /// `note` is the fully-formed Note JSON (including id, type, content, etc.).
+    /// The activity ID is derived deterministically from the note's `id` field.
+    pub async fn broadcast_create_note(
+        &self,
+        local_user_id: uuid::Uuid,
+        note: serde_json::Value,
+    ) -> anyhow::Result<()> {
+        let data = self.federation_config.to_request_data();
+        let Some((local_actor, inboxes)) =
+            self.accepted_follower_inboxes(&data, local_user_id).await?
+        else {
+            return Ok(());
+        };
+
+        let note_id_str = note["id"].as_str().unwrap_or("");
+        let create_id = Url::parse(&format!(
+            "{}/activities/create/{}",
+            self.base_url,
+            uuid::Uuid::new_v5(&uuid::Uuid::NAMESPACE_URL, note_id_str.as_bytes())
+        ))
+        .map_err(|e| anyhow::anyhow!("{e}"))?;
+
+        let create = crate::activities::CreateActivity {
+            id: create_id,
+            kind: Default::default(),
+            actor: ObjectId::from(local_actor.ap_id.clone()),
+            object: note,
+            to: vec![crate::urls::AS_PUBLIC.to_string()],
+            cc: vec![local_actor.followers_url.to_string()],
+            bto: vec![],
+            bcc: vec![],
+        };
+        let sends = SendActivityTask::prepare(
+            &WithContext::new_default(create),
+            &local_actor,
+            inboxes,
+            &data,
+        )
+        .await?;
+        let failures = send_with_retry(sends, &data).await;
+        if !failures.is_empty() {
+            tracing::warn!(count = failures.len(), "some Create(Note) deliveries failed");
+        }
+        Ok(())
+    }
+
+    /// Fan out an Update(Note) activity to all accepted followers.
+    /// `note` is the fully-formed Note JSON.
+    pub async fn broadcast_update_note(
+        &self,
+        local_user_id: uuid::Uuid,
+        note: serde_json::Value,
+    ) -> anyhow::Result<()> {
+        let data = self.federation_config.to_request_data();
+        let Some((local_actor, inboxes)) =
+            self.accepted_follower_inboxes(&data, local_user_id).await?
+        else {
+            return Ok(());
+        };
+
+        let update_id = crate::urls::activity_url(&self.base_url)
+            .map_err(|e| anyhow::anyhow!("{e}"))?;
+
+        let update = crate::activities::UpdateActivity {
+            id: update_id,
+            kind: Default::default(),
+            actor: ObjectId::from(local_actor.ap_id.clone()),
+            object: note,
+            to: vec![crate::urls::AS_PUBLIC.to_string()],
+            cc: vec![local_actor.followers_url.to_string()],
+        };
+        let sends = SendActivityTask::prepare(
+            &WithContext::new_default(update),
+            &local_actor,
+            inboxes,
+            &data,
+        )
+        .await?;
+        let failures = send_with_retry(sends, &data).await;
+        if !failures.is_empty() {
+            tracing::warn!(count = failures.len(), "some Update(Note) deliveries failed");
+        }
+        Ok(())
+    }
+
     pub async fn broadcast_actor_update(&self, user_id: uuid::Uuid) -> anyhow::Result<()> {
         use activitypub_federation::traits::Object;