add top-level routing_preferences with selection_policy and model metrics fetch

crates/brightstaff/src/main.rs

@@ -6,6 +6,7 @@ use brightstaff::handlers::llm::llm_chat;
 use brightstaff::handlers::models::list_models;
 use brightstaff::handlers::routing_service::routing_decision;
 use brightstaff::router::llm::RouterService;
+use brightstaff::router::model_metrics::ModelMetricsService;
 use brightstaff::router::orchestrator::OrchestratorService;
 use brightstaff::state::memory::MemoryConversationalStorage;
 use brightstaff::state::postgresql::PostgreSQLConversationStorage;
@@ -40,6 +41,17 @@ const DEFAULT_ROUTING_MODEL_NAME: &str = "Arch-Router";
 const DEFAULT_ORCHESTRATOR_LLM_PROVIDER: &str = "plano-orchestrator";
 const DEFAULT_ORCHESTRATOR_MODEL_NAME: &str = "Plano-Orchestrator";
 
+/// Parse a version string like `v0.4.0`, `v0.3.0`, `0.2.0` into a `(major, minor, patch)` tuple.
+/// Missing parts default to 0. Non-numeric parts are treated as 0.
+fn parse_semver(version: &str) -> (u32, u32, u32) {
+    let v = version.trim_start_matches('v');
+    let mut parts = v.splitn(3, '.').map(|p| p.parse::<u32>().unwrap_or(0));
+    let major = parts.next().unwrap_or(0);
+    let minor = parts.next().unwrap_or(0);
+    let patch = parts.next().unwrap_or(0);
+    (major, minor, patch)
+}
+
 /// CORS pre-flight response for the models endpoint.
 fn cors_preflight() -> Result<Response<BoxBody<Bytes, hyper::Error>>, hyper::Error> {
     let mut response = Response::new(empty());
@@ -162,8 +174,69 @@ async fn init_app_state(
         .map(|p| p.name.clone())
         .unwrap_or_else(|| DEFAULT_ROUTING_LLM_PROVIDER.to_string());
 
+    // Validate version-gated routing_preferences rules.
+    let config_version = parse_semver(&config.version);
+    let is_v040_plus = config_version >= (0, 4, 0);
+
+    if is_v040_plus {
+        // v0.4.0+: per-provider routing_preferences are forbidden.
+        let providers_with_per_provider_prefs: Vec<&str> = config
+            .model_providers
+            .iter()
+            .filter(|p| p.routing_preferences.is_some())
+            .filter_map(|p| p.model.as_deref())
+            .collect();
+        if !providers_with_per_provider_prefs.is_empty() {
+            return Err(format!(
+                "routing_preferences inside model_providers is not allowed in v0.4.0+. \
+                 Use the top-level routing_preferences instead. \
+                 Offending models: {}",
+                providers_with_per_provider_prefs.join(", ")
+            )
+            .into());
+        }
+    } else if config.routing_preferences.is_some() {
+        return Err(
+            "top-level routing_preferences requires version v0.4.0 or above. \
+             Update the version field or remove routing_preferences."
+                .into(),
+        );
+    }
+
+    // Validate that all models referenced in top-level routing_preferences exist in model_providers.
+    if let Some(ref route_prefs) = config.routing_preferences {
+        let provider_model_names: std::collections::HashSet<&str> = config
+            .model_providers
+            .iter()
+            .flat_map(|p| p.model.as_deref())
+            .collect();
+        for pref in route_prefs {
+            for model in &pref.models {
+                if !provider_model_names.contains(model.as_str()) {
+                    return Err(format!(
+                        "routing_preferences route '{}' references model '{}' \
+                         which is not declared in model_providers",
+                        pref.name, model
+                    )
+                    .into());
+                }
+            }
+        }
+    }
+
+    // Initialize ModelMetricsService if model_metrics_sources is configured.
+    let metrics_service: Option<Arc<ModelMetricsService>> =
+        if let Some(ref sources) = config.model_metrics_sources {
+            let svc = ModelMetricsService::new(sources, reqwest::Client::new()).await;
+            Some(Arc::new(svc))
+        } else {
+            None
+        };
+
     let router_service = Arc::new(RouterService::new(
         config.model_providers.clone(),
+        config.routing_preferences.clone(),
+        metrics_service,
         format!("{llm_provider_url}{CHAT_COMPLETIONS_PATH}"),
         routing_model_name,
         routing_llm_provider,