feat(api): add library sync background task

k-tv-backend/api/src/library_scheduler.rs

@@ -0,0 +1,64 @@
+//! Background library sync task.
+//! Fires 10 seconds after startup, then every N hours (read from app_settings).
+
+use std::sync::Arc;
+use std::time::Duration;
+
+use domain::IProviderRegistry;
+
+const STARTUP_DELAY_SECS: u64 = 10;
+const DEFAULT_INTERVAL_HOURS: u64 = 6;
+
+pub async fn run_library_sync(
+    sync_adapter: Arc<dyn domain::LibrarySyncAdapter>,
+    registry: Arc<tokio::sync::RwLock<Arc<infra::ProviderRegistry>>>,
+    app_settings_repo: Arc<dyn domain::IAppSettingsRepository>,
+) {
+    tokio::time::sleep(Duration::from_secs(STARTUP_DELAY_SECS)).await;
+
+    loop {
+        tick(&sync_adapter, &registry).await;
+
+        let interval_hours = load_interval_hours(&app_settings_repo).await;
+        tokio::time::sleep(Duration::from_secs(interval_hours * 3600)).await;
+    }
+}
+
+async fn load_interval_hours(repo: &Arc<dyn domain::IAppSettingsRepository>) -> u64 {
+    repo.get("library_sync_interval_hours")
+        .await
+        .ok()
+        .flatten()
+        .and_then(|v| v.parse::<u64>().ok())
+        .unwrap_or(DEFAULT_INTERVAL_HOURS)
+}
+
+async fn tick(
+    sync_adapter: &Arc<dyn domain::LibrarySyncAdapter>,
+    registry: &Arc<tokio::sync::RwLock<Arc<infra::ProviderRegistry>>>,
+) {
+    let reg = registry.read().await;
+    let provider_ids: Vec<String> = reg.provider_ids();
+    drop(reg);
+
+    for provider_id in provider_ids {
+        let reg = registry.read().await;
+        let provider = match reg.get_provider(&provider_id) {
+            Some(p) => p,
+            None => continue,
+        };
+        drop(reg);
+
+        tracing::info!("library-sync: syncing provider '{}'", provider_id);
+        let result = sync_adapter.sync_provider(provider.as_ref(), &provider_id).await;
+
+        if let Some(ref err) = result.error {
+            tracing::warn!("library-sync: provider '{}' failed: {}", provider_id, err);
+        } else {
+            tracing::info!(
+                "library-sync: provider '{}' done — {} items in {}ms",
+                provider_id, result.items_found, result.duration_ms
+            );
+        }
+    }
+}