feat(provider): add ProviderManager to coordinate providers and cache health status

- Introduce `ProviderManager` for registering providers, routing generate calls, listing models, and refreshing health in parallel.
- Maintain a status cache to expose the last known health of each provider.
- Update `provider` module to re‑export the new manager alongside existing types.

crates/owlen-core/src/provider/manager.rs

@@ -0,0 +1,227 @@
+use std::collections::HashMap;
+use std::sync::Arc;
+
+use futures::stream::{FuturesUnordered, StreamExt};
+use log::{debug, warn};
+use tokio::sync::RwLock;
+
+use crate::config::Config;
+use crate::{Error, Result};
+
+use super::{GenerateRequest, GenerateStream, ModelInfo, ModelProvider, ProviderStatus};
+
+/// Model information annotated with the originating provider metadata.
+#[derive(Debug, Clone)]
+pub struct AnnotatedModelInfo {
+    pub provider_id: String,
+    pub provider_status: ProviderStatus,
+    pub model: ModelInfo,
+}
+
+/// Coordinates multiple [`ModelProvider`] implementations and tracks their
+/// health state.
+pub struct ProviderManager {
+    providers: RwLock<HashMap<String, Arc<dyn ModelProvider>>>,
+    status_cache: RwLock<HashMap<String, ProviderStatus>>,
+}
+
+impl ProviderManager {
+    /// Construct a new manager using the supplied configuration. Providers
+    /// defined in the configuration start with a `RequiresSetup` status so
+    /// that frontends can surface incomplete configuration to users.
+    pub fn new(config: &Config) -> Self {
+        let mut status_cache = HashMap::new();
+        for provider_id in config.providers.keys() {
+            status_cache.insert(provider_id.clone(), ProviderStatus::RequiresSetup);
+        }
+
+        Self {
+            providers: RwLock::new(HashMap::new()),
+            status_cache: RwLock::new(status_cache),
+        }
+    }
+
+    /// Register a provider instance with the manager.
+    pub async fn register_provider(&self, provider: Arc<dyn ModelProvider>) {
+        let provider_id = provider.metadata().id.clone();
+        debug!("registering provider {}", provider_id);
+
+        self.providers
+            .write()
+            .await
+            .insert(provider_id.clone(), provider);
+        self.status_cache
+            .write()
+            .await
+            .insert(provider_id, ProviderStatus::Unavailable);
+    }
+
+    /// Return a stream by routing the request to the designated provider.
+    pub async fn generate(
+        &self,
+        provider_id: &str,
+        request: GenerateRequest,
+    ) -> Result<GenerateStream> {
+        let provider = {
+            let guard = self.providers.read().await;
+            guard.get(provider_id).cloned()
+        }
+        .ok_or_else(|| Error::Config(format!("provider '{provider_id}' not registered")))?;
+
+        match provider.generate_stream(request).await {
+            Ok(stream) => {
+                self.status_cache
+                    .write()
+                    .await
+                    .insert(provider_id.to_string(), ProviderStatus::Available);
+                Ok(stream)
+            }
+            Err(err) => {
+                self.status_cache
+                    .write()
+                    .await
+                    .insert(provider_id.to_string(), ProviderStatus::Unavailable);
+                Err(err)
+            }
+        }
+    }
+
+    /// List models across all providers, updating provider status along the way.
+    pub async fn list_all_models(&self) -> Result<Vec<AnnotatedModelInfo>> {
+        let providers: Vec<(String, Arc<dyn ModelProvider>)> = {
+            let guard = self.providers.read().await;
+            guard
+                .iter()
+                .map(|(id, provider)| (id.clone(), Arc::clone(provider)))
+                .collect()
+        };
+
+        let mut tasks = FuturesUnordered::new();
+
+        for (provider_id, provider) in providers {
+            tasks.push(async move {
+                let log_id = provider_id.clone();
+                let mut status = ProviderStatus::Unavailable;
+                let mut models = Vec::new();
+
+                match provider.health_check().await {
+                    Ok(health) => {
+                        status = health;
+                        if matches!(status, ProviderStatus::Available) {
+                            match provider.list_models().await {
+                                Ok(list) => {
+                                    models = list;
+                                }
+                                Err(err) => {
+                                    status = ProviderStatus::Unavailable;
+                                    warn!("listing models failed for provider {}: {}", log_id, err);
+                                }
+                            }
+                        }
+                    }
+                    Err(err) => {
+                        warn!("health check failed for provider {}: {}", log_id, err);
+                    }
+                }
+
+                (provider_id, status, models)
+            });
+        }
+
+        let mut annotated = Vec::new();
+        let mut status_updates = HashMap::new();
+
+        while let Some((provider_id, status, models)) = tasks.next().await {
+            status_updates.insert(provider_id.clone(), status);
+            for model in models {
+                annotated.push(AnnotatedModelInfo {
+                    provider_id: provider_id.clone(),
+                    provider_status: status,
+                    model,
+                });
+            }
+        }
+
+        {
+            let mut guard = self.status_cache.write().await;
+            for (provider_id, status) in status_updates {
+                guard.insert(provider_id, status);
+            }
+        }
+
+        Ok(annotated)
+    }
+
+    /// Refresh the health of all registered providers in parallel, returning
+    /// the latest status snapshot.
+    pub async fn refresh_health(&self) -> HashMap<String, ProviderStatus> {
+        let providers: Vec<(String, Arc<dyn ModelProvider>)> = {
+            let guard = self.providers.read().await;
+            guard
+                .iter()
+                .map(|(id, provider)| (id.clone(), Arc::clone(provider)))
+                .collect()
+        };
+
+        let mut tasks = FuturesUnordered::new();
+        for (provider_id, provider) in providers {
+            tasks.push(async move {
+                let status = match provider.health_check().await {
+                    Ok(status) => status,
+                    Err(err) => {
+                        warn!("health check failed for provider {}: {}", provider_id, err);
+                        ProviderStatus::Unavailable
+                    }
+                };
+                (provider_id, status)
+            });
+        }
+
+        let mut updates = HashMap::new();
+        while let Some((provider_id, status)) = tasks.next().await {
+            updates.insert(provider_id, status);
+        }
+
+        {
+            let mut guard = self.status_cache.write().await;
+            for (provider_id, status) in &updates {
+                guard.insert(provider_id.clone(), *status);
+            }
+        }
+
+        updates
+    }
+
+    /// Return the provider instance for an identifier.
+    pub async fn get_provider(&self, provider_id: &str) -> Option<Arc<dyn ModelProvider>> {
+        let guard = self.providers.read().await;
+        guard.get(provider_id).cloned()
+    }
+
+    /// List the registered provider identifiers.
+    pub async fn provider_ids(&self) -> Vec<String> {
+        let guard = self.providers.read().await;
+        guard.keys().cloned().collect()
+    }
+
+    /// Retrieve the last known status for a provider.
+    pub async fn provider_status(&self, provider_id: &str) -> Option<ProviderStatus> {
+        let guard = self.status_cache.read().await;
+        guard.get(provider_id).copied()
+    }
+
+    /// Snapshot the currently cached statuses.
+    pub async fn provider_statuses(&self) -> HashMap<String, ProviderStatus> {
+        let guard = self.status_cache.read().await;
+        guard.clone()
+    }
+}
+
+impl Default for ProviderManager {
+    fn default() -> Self {
+        Self {
+            providers: RwLock::new(HashMap::new()),
+            status_cache: RwLock::new(HashMap::new()),
+        }
+    }
+}

crates/owlen-core/src/provider/mod.rs

@@ -2,8 +2,10 @@
 //!
 //! This module defines the async [`ModelProvider`] trait that all model
 //! backends implement, together with a small suite of shared data structures
-//! used for model discovery and streaming generation.
+//! used for model discovery and streaming generation. The [`ProviderManager`]
+//! orchestrates multiple providers and coordinates their health state.
 
+mod manager;
 mod types;
 
 use std::pin::Pin;
@@ -11,7 +13,7 @@ use std::pin::Pin;
 use async_trait::async_trait;
 use futures::Stream;
 
-pub use self::types::*;
+pub use self::{manager::*, types::*};
 
 use crate::Result;