//! Service registry — the global lookup table for service proxies.

use crate::{proxy::ServiceProxy, ServiceError, ServiceResult};
use std::collections::HashMap;
use std::sync::{Arc, RwLock};

/// Global registry of all service proxies.
///
/// The framework maintains one registry per application. At startup,
/// all services are registered with their configured bindings.
/// Components call `registry.get("UserService")` to get the proxy.
#[derive(Default)]
pub struct ServiceRegistry {
    services: RwLock<HashMap<String, Arc<ServiceProxy>>>,
}

impl ServiceRegistry {
    pub fn new() -> Self {
        Self::default()
    }

    /// Register a service proxy.
    pub fn register(&self, proxy: ServiceProxy) {
        let name = proxy.service_name.clone();
        self.services
            .write()
            .expect("lock poisoned")
            .insert(name, Arc::new(proxy));
    }

    /// Get a service proxy by name.
    pub fn get(&self, name: &str) -> ServiceResult<Arc<ServiceProxy>> {
        self.services
            .read()
            .expect("lock poisoned")
            .get(name)
            .cloned()
            .ok_or_else(|| ServiceError::NotFound(name.to_string()))
    }

    /// List all registered service names.
    pub fn service_names(&self) -> Vec<String> {
        self.services
            .read()
            .expect("lock poisoned")
            .keys()
            .cloned()
            .collect()
    }

    /// Number of registered services.
    pub fn len(&self) -> usize {
        self.services.read().expect("lock poisoned").len()
    }

    pub fn is_empty(&self) -> bool {
        self.len() == 0
    }
}