refactor: introduce TransportActor abstraction

server/crates/arbiter-useragent/Cargo.toml

@@ -12,4 +12,4 @@ tonic.workspace = true
 tracing.workspace = true
 ed25519-dalek.workspace = true
 smlang.workspace = true
-x25519-dalek.workspace = true
+x25519-dalek.workspace = true

server/crates/arbiter-useragent/src/lib.rs

@@ -1,13 +1,67 @@
+use arbiter_proto::proto::UserAgentRequest;
 use ed25519_dalek::SigningKey;
-use kameo::Actor;
+use kameo::{
+    Actor, Reply,
+    actor::{ActorRef, WeakActorRef},
+    prelude::Message,
+};
+use smlang::statemachine;
+use tokio::sync::mpsc;
 use tonic::transport::CertificateDer;
+use tracing::{debug, error};
 
 struct Storage {
     pub identity: SigningKey,
     pub server_ca_cert: CertificateDer<'static>,
 }
 
-#[derive(Actor)]
-pub struct UserAgent {
+#[derive(Debug)]
+pub enum InitError {
+    StorageError,
+    Other(String),
+}
 
-}
+statemachine! {
+    name: UserAgentStateMachine,
+    custom_error: false,
+    transitions: {
+        *Init + SendAuthChallenge = WaitingForAuthSolution
+    }
+}
+
+
+
+pub struct UserAgentActor<A: TransportActor<UserAgentRequest>> {
+    key: SigningKey,
+    server_ca_cert: CertificateDer<'static>,
+    sender: ActorRef<A>,
+}
+impl<A: TransportActor<UserAgentRequest>> Actor for UserAgentActor<A> {
+    type Args = Self;
+
+    type Error = InitError;
+
+    async fn on_start(args: Self::Args, actor_ref: ActorRef<Self>) -> Result<Self, Self::Error> {
+        todo!()
+    }
+
+    async fn on_link_died(
+        &mut self,
+        _: WeakActorRef<Self>,
+        id: kameo::prelude::ActorId,
+        _: kameo::prelude::ActorStopReason,
+    ) -> Result<std::ops::ControlFlow<kameo::prelude::ActorStopReason>, Self::Error> {
+        if id == self.sender.id() {
+            error!("Transport actor died, stopping UserAgentActor");
+            Ok(std::ops::ControlFlow::Break(
+                kameo::prelude::ActorStopReason::Normal,
+            ))
+        } else {
+            debug!(
+                "Linked actor {} died, but it's not the transport actor, ignoring",
+                id
+            );
+            Ok(std::ops::ControlFlow::Continue(()))
+        }
+    }
+}