rvoip-sip 0.2.3

//! Server-side REGISTER request handler
//!
//! This adapter orchestrates authentication between dialog-core (protocol layer)
//! and registrar-core (storage/validation layer) via the global event bus.
//!
//! ## Architecture
//!
//! ```text
//! dialog-core → IncomingRegister event → RegistrationAdapter → registrar-core
//!            ← SendRegisterResponse event ← RegistrationAdapter ←
//! ```

use crate::errors::{Result, SessionError};
use rvoip_infra_common::events::{
    coordinator::GlobalEventCoordinator,
    cross_crate::{DialogToSessionEvent, RvoipCrossCrateEvent, SessionToDialogEvent},
};
use rvoip_sip_registrar::{
    AddressOfRecord, ContactInfo, ContactReachability, RegistrarService, Transport,
};
use std::sync::Arc;
use tracing::{debug, info, warn};

/// Handles server-side REGISTER requests by coordinating authentication
pub struct RegistrationAdapter {
    registrar: Arc<RegistrarService>,
    global_coordinator: Arc<GlobalEventCoordinator>,
}

impl RegistrationAdapter {
    /// Create a new registration adapter
    pub fn new(
        registrar: Arc<RegistrarService>,
        global_coordinator: Arc<GlobalEventCoordinator>,
    ) -> Self {
        Self {
            registrar,
            global_coordinator,
        }
    }

    /// Handle incoming REGISTER request from dialog-core
    async fn handle_incoming_register(
        &self,
        transaction_id: String,
        from_uri: String,
        contact_uri: String,
        expires: u32,
        authorization: Option<String>,
    ) -> Result<()> {
        info!("🔐 Handling incoming REGISTER from {}", from_uri);

        let aor = Self::extract_aor(&from_uri)?;
        let username = aor.user().to_string();
        debug!("Extracted username: {}", username);

        // Call registrar-core to authenticate
        let (should_register, www_auth_challenge) = self
            .registrar
            .authenticate_register(&username, authorization.as_deref(), "REGISTER", &from_uri)
            .await
            .map_err(|e| SessionError::RegistrationFailed(e.to_string()))?;

        if should_register {
            // Valid credentials - register user
            info!("✅ Authentication successful for {}", username);

            // Build ContactInfo
            let contact = ContactInfo {
                uri: contact_uri.clone(),
                instance_id: uuid::Uuid::new_v4().to_string(),
                transport: Transport::UDP,
                user_agent: "rvoip-sip".to_string(),
                expires: chrono::Utc::now()
                    + chrono::Duration::try_seconds(expires as i64)
                        .unwrap_or_else(|| chrono::Duration::seconds(3600)),
                q_value: 1.0,
                received: None,
                path: Vec::new(),
                methods: vec!["INVITE".to_string(), "ACK".to_string(), "BYE".to_string()],
                reg_id: None,
                flow_id: None,
                reachability: ContactReachability::Unknown,
            };

            // Register the full AOR in registrar-core so domains do not collide.
            self.registrar
                .register_aor(&aor, contact, Some(expires))
                .await
                .map_err(|e| SessionError::RegistrationFailed(e.to_string()))?;

            // Publish 200 OK response event
            let response_event =
                RvoipCrossCrateEvent::SessionToDialog(SessionToDialogEvent::SendRegisterResponse {
                    transaction_id,
                    status_code: 200,
                    reason: "OK".to_string(),
                    www_authenticate: None,
                    contact: Some(contact_uri),
                    expires: Some(expires),
                    min_expires: None,
                    service_route: Vec::new(),
                    path_echo: false,
                    associated_uri: Vec::new(),
                    extra_headers: Vec::new(),
                });

            self.global_coordinator
                .publish(Arc::new(response_event))
                .await
                .map_err(|e| {
                    SessionError::InternalError(format!("Failed to publish 200 OK: {}", e))
                })?;

            info!("✅ User {} registered, sent 200 OK", username);
        } else {
            // Need authentication - send 401 challenge
            info!("🔐 Sending 401 challenge for {}", username);

            let response_event =
                RvoipCrossCrateEvent::SessionToDialog(SessionToDialogEvent::SendRegisterResponse {
                    transaction_id,
                    status_code: 401,
                    reason: "Unauthorized".to_string(),
                    www_authenticate: www_auth_challenge,
                    contact: None,
                    expires: None,
                    min_expires: None,
                    service_route: Vec::new(),
                    path_echo: false,
                    associated_uri: Vec::new(),
                    extra_headers: Vec::new(),
                });

            self.global_coordinator
                .publish(Arc::new(response_event))
                .await
                .map_err(|e| {
                    SessionError::InternalError(format!("Failed to publish 401: {}", e))
                })?;

            info!("✅ Sent 401 challenge for {}", username);
        }

        Ok(())
    }

    /// Subscribe to IncomingRegister events and start handling them
    pub async fn start(self: Arc<Self>) -> Result<()> {
        info!("🎬 Starting RegistrationAdapter - subscribing to dialog_to_session events");

        // Subscribe to dialog-to-session events
        let mut receiver = self
            .global_coordinator
            .subscribe("dialog_to_session")
            .await
            .map_err(|e| SessionError::InternalError(format!("Subscribe failed: {}", e)))?;

        let handler = self.clone();

        tokio::spawn(async move {
            info!("🔔 RegistrationAdapter event loop started");

            loop {
                // Receive event from bus
                match receiver.recv().await {
                    Some(event_arc) => {
                        // Use trait-based downcasting via as_any()
                        if let Some(concrete) =
                            event_arc.as_any().downcast_ref::<RvoipCrossCrateEvent>()
                        {
                            // Check if it's an IncomingRegister event
                            if let RvoipCrossCrateEvent::DialogToSession(
                                DialogToSessionEvent::IncomingRegister {
                                    transaction_id,
                                    from_uri,
                                    contact_uri,
                                    expires,
                                    authorization,
                                    ..
                                },
                            ) = concrete
                            {
                                debug!("📩 Received IncomingRegister for {}", from_uri);

                                if let Err(e) = handler
                                    .handle_incoming_register(
                                        transaction_id.clone(),
                                        from_uri.clone(),
                                        contact_uri.clone(),
                                        *expires,
                                        authorization.clone(),
                                    )
                                    .await
                                {
                                    warn!("Failed to handle REGISTER: {}", e);
                                }
                            }
                        }
                    }
                    None => {
                        debug!("RegistrationAdapter event channel closed");
                        break;
                    }
                }
            }

            info!("🛑 RegistrationAdapter event loop stopped");
        });

        info!("✅ RegistrationAdapter started and subscribed to dialog_to_session events");
        Ok(())
    }

    fn extract_aor(uri: &str) -> Result<AddressOfRecord> {
        AddressOfRecord::parse(uri)
            .map_err(|error| SessionError::InvalidInput(format!("Invalid AOR: {error}")))
    }
}