Partial inbox handler

bin/pupctl/src/main.rs

@@ -1,7 +1,12 @@
 //! Control program for the ActivityPub federated social media server.
 #![feature(iterator_try_collect)]
 
-use puppy::{actor::Actor, config::Config, Context};
+use puppy::{
+    actor::Actor,
+    config::Config,
+    data::{FollowRequest, Object, Profile},
+    Context,
+};
 
 #[tokio::main]
 async fn main() -> puppy::Result<()> {
@@ -14,8 +19,19 @@ async fn main() -> puppy::Result<()> {
     };
     let cx = Context::load(config)?;
     let riley = get_or_create_actor(&cx, "riley")?;
-    let post = puppy::post::create_post(&cx, riley.key, "i like boys")?;
+    cx.run(|tx| {
-    puppy::post::federate_post(&cx, post).await
+        println!("\nRiley's following:");
+        for FollowRequest { id, origin, .. } in
+            riley.pending_requests(&tx).try_collect::<Vec<_>>()?
+        {
+            let Profile { account_name, .. } = tx.get_mixin(origin)?.unwrap();
+            let Object { id, .. } = tx.get_mixin(id)?.unwrap();
+            println!("- @{account_name} ({origin}) (request url = {id})");
+        }
+        Ok(())
+    })
+    // let post = puppy::post::create_post(&cx, riley.key, "i like boys")?;
+    // puppy::post::federate_post(&cx, post).await
 
     // let linen = get_or_create_actor(&cx, "linen")?;
     // if true {

bin/server/src/api.rs

@@ -1,6 +1,6 @@
 //! API endpoints and request handlers.
 
-use std::convert::Infallible;
+use std::{convert::Infallible, future::Future};
 use std::net::SocketAddr;
 use std::sync::Arc;
 
@@ -164,6 +164,7 @@ async fn handle(req: Request, verifier: &Verifier, cx: Context) -> Result<Respon
     };
     // Simplified representation of a request, so we can pattern match on it more easily in the dispatchers.
     let req = Req::simplify(&request);
+    println!("{} {}", request.method(), request.uri());
     // We'll use the path to pick where specifically to send the request.
     // Check request signature at the door. Even if it isn't needed for a particular endpoint, failing fast
     // with a clear error message will save anyone trying to get *their* signatures implementation a major
@@ -185,7 +186,17 @@ async fn handle(req: Request, verifier: &Verifier, cx: Context) -> Result<Respon
     };
     // If one of the endpoints gave us an error message, we convert that into a response and then
     // serve it to the client. In either case, we just serve a response.
-    Ok(res.unwrap_or_else(|msg| req.error(msg)))
+    let response = res.unwrap_or_else(|msg| {
+        println!("{} {}: [error] {msg}", request.method(), request.uri());
+        req.error(msg)
+    });
+    println! {
+        "{} {}: {}",
+        request.method(),
+        request.uri(),
+        response.status()
+    };
+    Ok(response)
 }
 
 const POST: &Method = &Method::POST;
@@ -208,11 +219,9 @@ async fn dispatch_signed(
         // verification actor lives.
         (GET, ["o", ulid]) => ap::serve_object(&cx, ulid),
         // POSTs to an actor's inbox need to be signed to prevent impersonation.
-        (POST, ["o", ulid, "inbox"]) => with_json(&req.body, |json| try {
+        (POST, ["o", ulid, "inbox"]) => {
-            // We only handle the intermediate parsing of the json, full resolution of the
+            with_json(&req.body, |json| ap::inbox(&cx, ulid, sig, json)).await
-            // activity object will happen inside the inbox handler itself.
+        }
-            ap::inbox(&cx, ulid, sig, json)
-        }),
         // Try the resources for which no signature is required as well.
         _ => dispatch_public(cx, verifier, req).await,
     }
@@ -236,12 +245,12 @@ async fn dispatch_public(
     }
 }
 
-fn with_json(
+async fn with_json<F>(body: &[u8], f: impl FnOnce(Value) -> F) -> Result<Response, Message>
-    body: &[u8],
+where
-    f: impl FnOnce(Value) -> Result<Response, Message>,
+    F: Future<Output = Result<Response, Message>>,
-) -> Result<Response, Message> {
+{
     match from_slice(body) {
-        Ok(json) => f(json),
+        Ok(json) => f(json).await,
         Err(e) => fuck!(400: "could not decode json: {e}"),
     }
 }
@@ -262,6 +271,12 @@ mod error {
         pub status: u16,
     }
 
+    impl std::fmt::Display for Message {
+        fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+            self.error.fmt(f)
+        }
+    }
+
     impl super::Req<'_> {
         /// Generate an error response for the request.
         pub fn error(&self, err: Message) -> Response {

bin/server/src/api/ap.rs

@@ -4,6 +4,7 @@ use http_body_util::Full;
 use hyper::body::Bytes;
 use puppy::{
     actor::{get_signing_key, Actor},
+    fetch::object::Activity,
     get_local_ap_object, Context, Error, Key,
 };
 use serde_json::Value;
@@ -62,8 +63,23 @@ pub async fn outbox(cx: &Context, params: &[(&str, &str)]) -> Result<Response, M
 }
 
 /// Handle POSTs to actor inboxes. Requires request signature.
-pub fn inbox(cx: &Context, actor_id: &str, sig: Signer, body: Value) -> Response {
+pub async fn inbox(
-    todo!()
+    cx: &Context,
+    actor_id: &str,
+    sig: Signer,
+    body: Value,
+) -> Result<Response, Message> {
+    let receiver = actor_id.parse::<Key>().unwrap();
+    match Activity::from_json(body) {
+        Ok(activity) => {
+            puppy::ingest(&cx, receiver, &activity).await.unwrap();
+            match puppy::interpret(&cx, activity) {
+                Ok(_) => Ok(respond!(code: 202)),
+                Err(err) => fuck!(400: "error interpreting activity: {err}"),
+            }
+        }
+        Err(err) => fuck!(400: "invalid payload: {err}"),
+    }
 }
 
 /// Serve an ActivityPub object as json-ld.

lib/fetch/src/client.rs

@@ -23,6 +23,7 @@ pub const VERSION: &str = "0.0.1-dev";
 pub const ACTIVITYPUB_TYPE: &str = "application/activity+json";
 
 /// A client for sending ActivityPub and WebFinger requests with.
+#[derive(Clone)]
 pub struct Client {
     inner: reqwest::Client,
 }
@@ -53,12 +54,8 @@ impl Client {
             .expect("signature generation to work")
             .commit(&mut req);
 
-        let req = dbg!(req);
-
         let request = req.map(Body::from).try_into().unwrap();
-        let response = self.inner.execute(request).await.unwrap();
+        self.inner.execute(request).await.unwrap();
-        let body = dbg!(response).text().await.unwrap();
-        dbg!(body);
     }
     /// A high-level function to resolve a single ActivityPub ID using a signed request.
     pub async fn resolve(&self, key: &SigningKey, url: &str) -> Result<Value, FetchError> {
@@ -103,7 +100,6 @@ impl Client {
             .body(())
             .unwrap();
 
-        println!("[{system}]: using modern config");
         key.sign(Options::LEGACY, &req)
             .expect("signing error")
             .commit(&mut req);
@@ -130,13 +126,13 @@ enum Subsystem {
     /// The subsystem that dereferences ActivityPub URLs to JSON values.
     ///
     /// In addition, the resolver is used for resolving webfinger handles to ActivityPub actors.
-    #[display = "resolver"]
+    #[display(fmt = "resolver")]
     Resolver,
     /// The subsystem responsible for delivering activities to inboxes.
-    #[display = "delivery"]
+    #[display(fmt = "delivery")]
     Delivery,
     /// For testing the resolver and signatures.
-    #[display = "devproxy"]
+    #[display(fmt = "devproxy")]
     DevProxy,
 }
 

lib/fetch/src/lib.rs

@@ -16,7 +16,7 @@ pub use client::Client;
 mod client;
 
 /// Deliver an activity to an inbox.
-pub async fn deliver(key: &SigningKey, activity: Activity, inbox: &str) {
+pub async fn deliver(key: &SigningKey, activity: &Activity, inbox: &str) {
     Client::new().deliver(key, &activity, inbox).await
 }
 
@@ -55,6 +55,9 @@ pub enum FetchError {
     /// message produced by the JSON deserializer.
     #[display(fmt = "deserialization error: {}", self.0)]
     BadJson(String),
+    /// A JSON-LD document could not be deserialized because it does not conform to our expectations.
+    #[display(fmt = "parsing error: {}", self.0)]
+    BadObject(String),
     /// An error that occurred while generating a signature for a a request.
     #[display(fmt = "signing error: {}", self.0)]
     Sig(String),

lib/fetch/src/object.rs

@@ -1,6 +1,7 @@
 //! ActivityPub vocabulary as interpreted by ActivityPuppy.
 
 use serde_json::{json, Value};
+use derive_more::From;
 
 pub use crate::signatures::Key as PublicKey;
 
@@ -11,11 +12,11 @@ pub struct Activity<T = String> {
     pub kind: T,
 }
 
-impl<K> Activity<K>
+impl<K> Activity<K> {
-where
+    pub fn to_json_ld(&self) -> Value
-    K: ToString,
+    where
-{
+        K: ToString,
-    pub fn to_json_ld(&self) -> Value {
+    {
         json!({
             "@context": [
                 "https://www.w3.org/ns/activitystreams",
@@ -28,6 +29,33 @@ where
         })
     }
 }
+impl Activity {
+    pub fn from_json(mut json: Value) -> Result<Activity, String> {
+        let Some(map) = json.as_object() else {
+            do yeet "expected an object"
+        };
+        let Some(id) = map.get("id").and_then(|s| s.as_str()).map(str::to_owned) else {
+            do yeet "missing `id` property"
+        };
+        let Some(actor) = map.get("actor").and_then(|s| s.as_str()).map(str::to_owned) else {
+            do yeet format!("missing `actor` property for activity {id}")
+        };
+        let Some(kind) = map.get("type").and_then(|s| s.as_str()).map(str::to_owned) else {
+            do yeet format!("missing `type` property for activity {id}")
+        };
+        // TODO: make this behave gracefully when we only get an ID.
+        let Some(object) = json
+            .get_mut("object")
+            .map(Value::take)
+            .map(Object::from_json)
+            .transpose()?
+            .map(Box::new)
+        else {
+            do yeet format!("missing or invalid `object` property for activity {id}")
+        };
+        Ok(Activity { id, actor, object, kind })
+    }
+}
 
 /// An actor is an entity capable of producing Takes.
 pub struct Actor {
@@ -64,11 +92,48 @@ impl Actor {
             }
         })
     }
+    pub fn from_json(json: Value) -> Result<Actor, String> {
+        let Value::Object(map) = json else {
+            do yeet format!("expected json object")
+        };
+        Ok(Actor {
+            id: map
+                .get("id")
+                .ok_or("id is required")?
+                .as_str()
+                .ok_or("id must be a str")?
+                .to_string(),
+            inbox: map
+                .get("inbox")
+                .ok_or("inbox is required")?
+                .as_str()
+                .ok_or("inbox must be a str")?
+                .to_string(),
+            account_name: map
+                .get("preferredUsername")
+                .ok_or("preferredUsername is required")?
+                .as_str()
+                .ok_or("preferredUsername must be a str")?
+                .to_string(),
+            display_name: map.get("name").and_then(|v| v.as_str()).map(str::to_owned),
+            public_key: map
+                .get("publicKey")
+                .cloned()
+                .and_then(PublicKey::from_json)
+                .ok_or("publicKey property could not be parsed")?,
+        })
+    }
 }
 
+#[derive(From)]
 pub enum Object {
+    #[from(ignore)]
+    Id {
+        id: String,
+    },
     Activity(Activity),
     Actor(Actor),
+    #[from(ignore)]
     Other {
         id: String,
         kind: String,
@@ -84,10 +149,52 @@ impl Object {
             Object::Activity(a) => &a.id,
             Object::Actor(a) => &a.id,
             Object::Other { id, .. } => id,
+            Object::Id { id } => id,
+        }
+    }
+    pub fn from_json(json: Value) -> Result<Object, String> {
+        if let Value::String(id) = json {
+            Ok(Object::Id { id })
+        } else if let Value::Object(ref map) = json {
+            match map.get("type").and_then(Value::as_str) {
+                Some("System" | "Application" | "Person" | "Service") => {
+                    Actor::from_json(json).map(Object::Actor)
+                }
+                Some("Create" | "Follow" | "Accept" | "Reject" | "Bite") => {
+                    Activity::from_json(json).map(Object::Activity)
+                }
+                Some(kind) => Ok(Object::Other {
+                    id: map
+                        .get("id")
+                        .ok_or("id is required")?
+                        .as_str()
+                        .ok_or("id must be a str")?
+                        .to_string(),
+                    kind: kind.to_string(),
+                    author: map
+                        .get("attributedTo")
+                        .ok_or("attributedTo is required")?
+                        .as_str()
+                        .ok_or("attributedTo must be a str")?
+                        .to_string(),
+                    content: map
+                        .get("content")
+                        .and_then(|v| v.as_str())
+                        .map(str::to_owned),
+                    summary: map
+                        .get("summary")
+                        .and_then(|v| v.as_str())
+                        .map(str::to_owned),
+                }),
+                None => do yeet "could not determine type of object",
+            }
+        } else {
+            Err(format!("expected a json object or an id, got {json:#?}"))
         }
     }
     pub fn to_json_ld(&self) -> Value {
         match self {
+            Object::Id { id } => json!(id),
             Object::Activity(a) => a.to_json_ld(),
             Object::Actor(a) => a.to_json_ld(),
             Object::Other {

lib/fetch/src/signatures.rs

@@ -649,8 +649,6 @@ mod new {
             .filter_map(|(k, v)| v.strip_prefix('"')?.strip_suffix('"').map(|v| (k, v)))
             .collect();
 
-        let table = dbg!(table);
-
         let Some(headers) = get(&table, "headers") else {
             do yeet "Missing `headers` field";
         };

lib/puppy/src/context.rs

@@ -1,3 +1,4 @@
+use fetch::Client;
 use store::{Key, Store, Transaction};
 
 use crate::{config::Config, Result};
@@ -8,17 +9,16 @@ use crate::{config::Config, Result};
 #[derive(Clone)]
 pub struct Context {
     config: Config,
+    client: Client,
     store: Store,
 }
 
 impl Context {
-    fn new(config: Config, store: Store) -> Context {
-        Context { config, store }
-    }
     /// Load the server context from the configuration.
     pub fn load(config: Config) -> Result<Context> {
         let store = Store::open(&config.state_dir, crate::data::schema())?;
-        Ok(Context { config, store })
+        let client = Client::new();
+        Ok(Context { config, store, client })
     }
     /// Do a data store [transaction][store::Transaction].
     pub fn run<T>(&self, f: impl FnOnce(&Transaction<'_>) -> Result<T>) -> Result<T> {
@@ -36,6 +36,10 @@ impl Context {
     pub fn mk_url(&self, key: Key) -> String {
         format!("https://{}/o/{key}", self.config.ap_domain)
     }
+    /// Access the federation client.
+    pub fn resolver(&self) -> &Client {
+        &self.client
+    }
 }
 
 /// Load a context for running tests in.
@@ -45,5 +49,6 @@ pub fn test_context<T>(
     schema: store::types::Schema,
     test: impl FnOnce(Context) -> Result<T>,
 ) -> Result<T> {
-    Store::test(schema, |store| test(Context { config, store }))
+    let client = Client::new();
+    Store::test(schema, |store| test(Context { config, store, client }))
 }

lib/puppy/src/interact.rs

@@ -11,7 +11,7 @@ use crate::{
 /// Interactions with other objects.
 impl Actor {
     /// Create a [`Bite`].
-    pub fn bite(&self, victim: &Actor) -> Bite {
+    pub fn bite(&self, victim: Actor) -> Bite {
         Bite {
             victim: victim.key,
             biter: self.key,
@@ -19,7 +19,7 @@ impl Actor {
         }
     }
     /// Construct a [`FollowRequest`].
-    pub fn follow_request(&self, target: &Actor) -> FollowRequest {
+    pub fn follow_request(&self, target: Actor) -> FollowRequest {
         FollowRequest {
             origin: self.key,
             target: target.key,
@@ -27,13 +27,13 @@ impl Actor {
         }
     }
     /// Makes `biter` bite `victim` and inserts the records into the database.
-    pub fn do_bite(&self, cx: &Context, victim: &Actor) -> Result<Bite> {
+    pub fn do_bite(&self, cx: &Context, victim: Actor) -> Result<Bite> {
         let bite = self.bite(victim);
-        cx.run(|tx| try { tx.create(bite) })?;
+        cx.run(|tx| tx.create(bite).map_err(Error::Store))?;
         Ok(bite)
     }
     /// Creates a follow request from `self` to `target`.
-    pub fn do_follow_request(&self, cx: &Context, target: &Actor) -> Result<FollowRequest> {
+    pub fn do_follow_request(&self, cx: &Context, target: Actor) -> Result<FollowRequest> {
         let req = self.follow_request(target);
         cx.run(|tx| {
             tx.create(req)?;
@@ -70,7 +70,7 @@ impl Actor {
             self.key == req.target,
             "only the target of a follow request may accept it"
         };
-        cx.run(|tx| try { tx.update(req.id, |_| Status::Rejected) })?;
+        cx.run(|tx| try { tx.update(req.id, |_| Status::Rejected)? })?;
         Ok(())
     }
     /// Get all pending follow request for `self`.
@@ -156,7 +156,7 @@ mod tests {
     fn create_fr() -> Result<()> {
         test_context(test_config(), schema(), |cx| {
             let (alice, bob) = make_test_actors(&cx)?;
-            alice.do_follow_request(&cx, &bob)?;
+            alice.do_follow_request(&cx, bob)?;
             assert!(
                 cx.store().exists::<FollowRequest>(alice.key, bob.key)?,
                 "(alice -> bob) ∈ follow-requested"
@@ -180,7 +180,7 @@ mod tests {
         test_context(test_config(), schema(), |cx| {
             let db = cx.store();
             let (alice, bob) = make_test_actors(&cx)?;
-            let req = alice.do_follow_request(&cx, &bob)?;
+            let req = alice.do_follow_request(&cx, bob)?;
             bob.do_accept_request(&cx, req)?;
 
             assert!(
@@ -210,7 +210,7 @@ mod tests {
     fn listing_follow_relations() -> Result<()> {
         test_context(test_config(), schema(), |cx| try {
             let (alice, bob) = make_test_actors(&cx)?;
-            let req = alice.do_follow_request(&cx, &bob)?;
+            let req = alice.do_follow_request(&cx, bob)?;
             bob.do_accept_request(&cx, req)?;
 
             cx.run(|tx| try {

lib/puppy/src/lib.rs

@@ -12,14 +12,16 @@
 // but that would make every type signature ever 100x more complicated, so we're not doing it.
 #![deny(clippy::disallowed_methods, clippy::disallowed_types)]
 
+use std::hint::unreachable_unchecked;
+
+use actor::{get_signing_key, Actor};
 pub use context::Context;
 #[cfg(test)]
 pub use context::test_context;
 
-use data::{
+use data::{ActivityKind, AuthorOf, Channel, Content, Create, Id, ObjectKind, Profile, PublicKey};
-    ActivityKind, AuthorOf, Channel, Content, Create, Id, Object, ObjectKind, Profile, PublicKey,
-};
 
+use fetch::object::{Activity, Object};
 use store::Transaction;
 pub use store::{self, Key, StoreError};
 pub use fetch::{self, FetchError};
@@ -30,11 +32,13 @@ pub mod data;
 pub mod post;
 mod interact;
 
+use derive_more::{From, Display};
+
 /// Retrieve an ActivityPub object from the database.
 ///
 /// Fails with `Error::Missing` if the required properties are not present.
 pub fn get_local_ap_object(tx: &Transaction<'_>, key: Key) -> Result<fetch::object::Object> {
-    let Some(obj) = tx.get_mixin::<Object>(key)? else {
+    let Some(obj) = tx.get_mixin::<data::Object>(key)? else {
         // We need this data in order to determine the object type. If the passed key does not
         // have this data, it must not be an ActivityPub object.
         return Err(Error::MissingData { node: key, prop: "Object" });
@@ -97,7 +101,10 @@ pub fn get_local_ap_object(tx: &Transaction<'_>, key: Key) -> Result<fetch::obje
 }
 
 pub mod actor {
-    use fetch::signatures::{Private, SigningKey};
+    use fetch::{
+        object,
+        signatures::{Private, SigningKey},
+    };
     use store::{Key, StoreError, Transaction};
 
     use crate::{
@@ -106,7 +113,7 @@ pub mod actor {
     };
 
     /// A reference to an actor.
-    #[derive(Clone, Eq, PartialEq, Debug)]
+    #[derive(Clone, Copy, Eq, PartialEq, Debug)]
     pub struct Actor {
         /// The key identifying the actor in the data store.
         pub key: Key,
@@ -118,7 +125,6 @@ pub mod actor {
             let maybe_key = tx
                 .lookup(Username(username.to_string()))
                 .map_err(Error::Store)?;
-            // For now, we only have local actors.
             Ok(maybe_key.map(|key| Actor { key }))
         }
     }
@@ -144,7 +150,33 @@ pub mod actor {
         })
     }
 
-    /// Add properties related to ActivityPub actors to a vertex.
+    /// Register an actor from another server.
+    pub fn create_remote(cx: &Context, object: object::Actor) -> Result<Actor> {
+        let key = Key::gen();
+        cx.run(|tx| {
+            tx.add_alias(key, Id(object.id.clone()))?;
+            tx.add_mixin(key, Channel { inbox: object.inbox })?;
+            tx.add_mixin(key, Object {
+                kind: ObjectKind::Actor,
+                id: Id(object.id),
+                local: false,
+            })?;
+            tx.add_mixin(key, Profile {
+                post_count: 0,
+                account_name: Username(object.account_name),
+                display_name: object.display_name,
+                about_string: None,
+                about_fields: Vec::new(),
+            })?;
+            tx.add_mixin(key, PublicKey {
+                key_id: object.public_key.id,
+                key_pem: object.public_key.inner,
+            })?;
+            Ok(Actor { key })
+        })
+    }
+
+    /// Add properties related to local ActivityPub actors to a vertex.
     pub fn mixin_ap_actor(
         tx: &Transaction<'_>,
         vertex: Key,
@@ -189,13 +221,16 @@ pub mod actor {
 
 pub type Result<T, E = Error> = std::result::Result<T, E>;
 
-#[derive(derive_more::From, Debug)]
+#[derive(From, Debug, Display)]
 pub enum Error {
     /// An error internal to the store.
+    #[display(fmt = "{}", self.0)]
     Store(StoreError),
     /// An error generated by the [fetch] subsystem.
+    #[display(fmt = "{}", self.0)]
     Fetch(FetchError),
     /// Expected `node` to have some property that it doesn't have.
+    #[display(fmt = "missing data: {node} is missing {prop}")]
     MissingData {
         /// The node that is missing the data.
         node: Key,
@@ -213,3 +248,99 @@ pub mod config {
         pub port: u16,
     }
 }
+
+/// Interpret an *incoming* activity. Outgoing activities are *never* interpreted through this function,
+/// because their changes are already in the database.
+// TODO: figure out if that is the behavior we actually want
+pub fn interpret(cx: &Context, activity: Activity) -> Result<()> {
+    // Fetch our actor from the database
+    let Some(actor) = cx.store().lookup(Id(activity.actor.clone()))? else {
+        panic!(
+            "actor {} does not exist in the database (id={})",
+            activity.actor, activity.id
+        )
+    };
+
+    // Fetch our object from the database. The object must already exist in the database.
+    let id = activity.object.id();
+    let Some(object) = cx.store().lookup(Id(id.to_owned()))? else {
+        panic!(
+            "object {} does not exist in the database (id={})",
+            activity.object.id(),
+            activity.id
+        )
+    };
+
+    let actor = actor::Actor { key: actor };
+    let (key, tag) = match activity.kind.as_str() {
+        "Bite" => {
+            let object = actor::Actor { key: object };
+            (actor.do_bite(&cx, object)?.id, ActivityKind::Bite)
+        }
+        "Create" => {
+            todo!()
+        }
+        "Follow" => {
+            let object = actor::Actor { key: object };
+
+            let req = actor.do_follow_request(&cx, object)?;
+            (req.id, ActivityKind::Follow)
+        }
+        tag @ ("Accept" | "Reject") => {
+            // Follow requests are multi-arrows in our graph, and they have their own activitypub id.
+            let Some(req) = cx.store().get_arrow(object)? else {
+                panic!(
+                    "follow request does not exist: {object} (id={})",
+                    activity.id
+                )
+            };
+            // Dispatch to the actual method based on the tag
+            let tag = match tag {
+                "Accept" => actor
+                    .do_accept_request(&cx, req)
+                    .map(|_| ActivityKind::Accept)?,
+                "Reject" => actor
+                    .do_reject_request(&cx, req)
+                    .map(|_| ActivityKind::Reject)?,
+                _ => unsafe {
+                    // SAFETY: this branch of the outer match only matches if the tag is either "Accept" or "Reject",
+                    // so this inner branch is truly unreachable.
+                    unreachable_unchecked()
+                },
+            };
+            (Key::gen(), tag)
+        }
+        k => panic!("unsupported activity type {k} (id={})", activity.id),
+    };
+    cx.run(|tx| {
+        tx.add_alias(key, Id(activity.id.clone()))?;
+        tx.add_mixin(key, data::Object {
+            id: Id(activity.id.clone()),
+            kind: ObjectKind::Activity(tag),
+            local: false,
+        })?;
+        Ok(())
+    })
+}
+
+/// Make sure all the interesting bits of an activity are here.
+pub async fn ingest(cx: &Context, auth: Key, activity: &Activity) -> Result<()> {
+    let key = cx.run(|tx| get_signing_key(tx, actor::Actor { key: auth }).map_err(Error::Store))?;
+    for id in [activity.actor.as_str(), activity.object.id()] {
+        if cx.store().lookup(Id(id.to_owned()))?.is_some() {
+            // Skip ingesting if we already know this ID.
+            continue;
+        }
+        let json = cx.resolver().resolve(&key, &id).await?;
+        let object = Object::from_json(json).unwrap();
+        match object {
+            Object::Activity(a) => interpret(&cx, a)?,
+            Object::Actor(a) => actor::create_remote(cx, a).map(void)?,
+            _ => todo!(),
+        }
+    }
+    Ok(())
+}
+
+/// Discard the argument.
+fn void<T>(_: T) -> () {}

lib/puppy/src/post.rs

@@ -13,8 +13,8 @@ use store::{util::IterExt as _, Key, Store, StoreError, Transaction};
 use crate::{
     actor::{get_signing_key, Actor},
     data::{
-        self, ActivityKind, AuthorOf, Content, Create, Id, ObjectKind, PrivateKey, Profile,
+        self, ActivityKind, AuthorOf, Channel, Content, Create, Follows, Id, ObjectKind,
-        PublicKey,
+        PrivateKey, Profile, PublicKey,
     },
     Context, Error,
 };
@@ -153,13 +153,14 @@ pub fn create_post(cx: &Context, author: Key, content: impl Into<Content>) -> cr
 
 pub async fn federate_post(cx: &Context, post: Post) -> crate::Result<()> {
     // Obtain all the data we need to construct our activity
-    let (Content { content, warning }, url, author, signing_key) = cx.run(|tx| try {
+    let (Content { content, warning }, url, author, signing_key, followers) = cx.run(|tx| try {
         let Some(AuthorOf { author, .. }) = tx.incoming(post.key).next().transpose()? else {
-            panic!()
+            panic!("can't federate post without author: {post:?}")
         };
         let signing_key = get_signing_key(tx, Actor { key: author })?;
         let (c, data::Object { id, .. }) = tx.get_mixin_many(post.key)?;
-        (c, id, author, signing_key)
+        let targets = tx.join_on::<Channel, _>(|a| a.follower, tx.incoming::<Follows>(author))?;
+        (c, id, author, signing_key, targets)
     })?;
 
     let activity_key = Key::gen();
@@ -194,12 +195,15 @@ pub async fn federate_post(cx: &Context, post: Post) -> crate::Result<()> {
         kind: "Create".to_string(),
     };
 
-    fetch::deliver(
+    for inbox in followers
-        &signing_key,
+        .into_iter()
-        activity,
+        .filter_map(|(_, c)| c.map(|t| t.inbox))
-        "https://crimew.gay/users/ezri/inbox",
+        // FIXME: remove this when im done testing
-    )
+        .chain(["https://crimew.gay/users/riley/inbox".to_string()])
-    .await;
+    {
+        fetch::deliver(&signing_key, &activity, &inbox).await;
+    }
+
     Ok(())
 }
 

lib/store/src/lib.rs

@@ -15,7 +15,7 @@
 
 use std::{cell::RefCell, path::Path, sync::Arc};
 
-use derive_more::From;
+use derive_more::{From, Display};
 use rocksdb::{Options, TransactionDBOptions, WriteBatchWithTransaction};
 use types::Schema;
 
@@ -139,7 +139,7 @@ pub const OK: Result<()> = Ok(());
 pub type Result<T, E = StoreError> = std::result::Result<T, E>;
 
 /// Errors from the data store.
-#[derive(From, Debug)]
+#[derive(From, Display, Debug)]
 pub enum StoreError {
     /// The requested value was expected to exist in a particular keyspace, but does not actually
     /// exist there. This can occur on updates for example.