feat: v2 rewrite — hexagonal arch, ActivityPub federation, NATS, deployment-ready (#1)

crates/worker/src/main.rs

@@ -0,0 +1,97 @@
+mod dlq;
+mod factory;
+mod handlers;
+mod outbox_relay;
+
+use domain::ports::EventConsumer;
+use futures::StreamExt;
+use nats::CONSUMER_MAX_DELIVER;
+
+#[tokio::main]
+async fn main() {
+    dotenvy::dotenv().ok();
+    tracing_subscriber::fmt()
+        .with_env_filter(tracing_subscriber::EnvFilter::from_default_env())
+        .init();
+
+    let database_url = std::env::var("DATABASE_URL").expect("DATABASE_URL required");
+    let nats_url = std::env::var("NATS_URL").unwrap_or_else(|_| "nats://localhost:4222".into());
+    let base_url = std::env::var("BASE_URL").expect("BASE_URL required");
+
+    tracing::info!("Building worker...");
+    let infra = factory::build(&database_url, &base_url, &nats_url).await;
+
+    // Spawn DLQ processor as a background task.
+    tokio::spawn(dlq::run_dlq_processor(
+        infra.dlq_store.clone(),
+        infra.event_publisher.clone(),
+    ));
+
+    // Spawn outbox relay — polls DB for undelivered events and publishes them.
+    tokio::spawn(
+        outbox_relay::OutboxRelay {
+            pool: infra.pool.clone(),
+            publisher: infra.event_publisher.clone(),
+            poll_interval: std::time::Duration::from_secs(5),
+        }
+        .run(),
+    );
+
+    tracing::info!("Worker started, consuming events...");
+    let mut stream = infra.consumer.consume();
+    while let Some(result) = stream.next().await {
+        match result {
+            Ok(envelope) => {
+                let event = &envelope.event;
+                tracing::debug!(?event, "received event");
+
+                let n = infra.handlers.notification.handle(event).await;
+                let f = infra.handlers.federation.handle(event).await;
+
+                if n.is_ok() && f.is_ok() {
+                    (envelope.ack)();
+                } else {
+                    if let Err(e) = &n {
+                        tracing::error!("notification handler: {e}");
+                    }
+                    if let Err(e) = &f {
+                        tracing::error!("federation handler: {e}");
+                    }
+
+                    // Last delivery attempt -> move to DLQ then ack.
+                    // Earlier attempts -> nack so NATS retries.
+                    if envelope.delivery_count >= CONSUMER_MAX_DELIVER as u64 {
+                        let error_msg = n
+                            .err()
+                            .or(f.err())
+                            .map(|e| e.to_string())
+                            .unwrap_or_else(|| "unknown error".into());
+
+                        // Serialize event back to payload for storage.
+                        let ep = event_payload::EventPayload::from(event);
+                        let event_type = ep.subject().to_string();
+                        let payload = serde_json::to_value(&ep).unwrap_or(serde_json::Value::Null);
+
+                        if let Err(e) = infra
+                            .dlq_store
+                            .insert(&event_type, &payload, &error_msg)
+                            .await
+                        {
+                            tracing::error!("DLQ insert failed: {e} — message lost");
+                        } else {
+                            tracing::warn!(
+                                event_type,
+                                delivery_count = envelope.delivery_count,
+                                "event exhausted — moved to DLQ"
+                            );
+                        }
+                        (envelope.ack)(); // ack from NATS — DLQ owns it now
+                    } else {
+                        (envelope.nack)();
+                    }
+                }
+            }
+            Err(e) => tracing::error!("consumer error: {e}"),
+        }
+    }
+}