Add reconcile loop scheduler (#69)

crates/arr-daemon/src/main.rs

@@ -1,6 +1,7 @@
 //! arr — reconcile loop and process entry point. See DESIGN.md §8.
 
 mod config;
+pub mod reconcile;
 mod web;
 
 use std::process::ExitCode;
@@ -11,6 +12,7 @@ use arr_compat::CompatState;
 use arr_db::Db;
 use arr_meta::TmdbClient;
 use config::Config;
+use reconcile::ReconcileLoop;
 use tower_http::trace::TraceLayer;
 
 /// Dump the `OpenAPI` document and exit, instead of serving. `just gen-client`
@@ -72,12 +74,15 @@ enum Error {
     },
     #[error("serve: {0}")]
     Serve(std::io::Error),
+    #[error("reconcile task: {0}")]
+    ReconcileTask(#[from] tokio::task::JoinError),
 }
 
 async fn run() -> Result<(), Error> {
     let config = Config::load()?;
     let database = Db::connect(&config.database_path).await?;
     database.migrate().await?;
+    let reconcile = ReconcileLoop::new(database.clone());
 
     // Jellyseerr's Radarr shim (DESIGN.md §9.4) reads the same database and
     // needs its own TMDB client for `movie/lookup`.
@@ -112,10 +117,30 @@ async fn run() -> Result<(), Error> {
 
     tracing::info!(addr = %config.bind_addr, docs = arr_api::DOCS_PATH, "listening");
 
-    axum::serve(listener, app)
-        .with_graceful_shutdown(shutdown())
-        .await
-        .map_err(Error::Serve)
+    let (shutdown_tx, shutdown_rx) = tokio::sync::watch::channel(false);
+    let mut reconcile_task = tokio::spawn(reconcile.run(shutdown_rx));
+    let signal_tx = shutdown_tx.clone();
+    let server = async move {
+        axum::serve(listener, app)
+            .with_graceful_shutdown(async move {
+                shutdown().await;
+                let _ = signal_tx.send(true);
+            })
+            .await
+    };
+    tokio::pin!(server);
+
+    tokio::select! {
+        result = &mut server => {
+            let _ = shutdown_tx.send(true);
+            reconcile_task.await?;
+            result.map_err(Error::Serve)
+        }
+        result = &mut reconcile_task => {
+            result?;
+            server.await.map_err(Error::Serve)
+        }
+    }
 }
 
 /// Stop accepting on Ctrl-C, or on the SIGTERM a service manager sends.