odin-protocol 1.0.0

//! Core protocol types and implementations for ODIN Protocol

use serde::{Deserialize, Serialize};
use std::collections::HashMap;
use std::time::{SystemTime, UNIX_EPOCH};
use tokio::sync::{broadcast, mpsc};
use async_trait::async_trait;
use crate::{Result, OdinError};
use crate::message::{OdinMessage, MessageType, MessagePriority};
use crate::config::OdinConfig;
use crate::metrics::MetricsCollector;

/// Main ODIN Protocol instance for AI-to-AI communication
#[derive(Debug)]
pub struct OdinProtocol {
    /// Configuration
    config: OdinConfig,
    /// Node identifier
    node_id: String,
    /// Network connections
    connections: HashMap<String, Connection>,
    /// Message broadcast channel
    message_tx: broadcast::Sender<OdinMessage>,
    /// Message receiver
    message_rx: broadcast::Receiver<OdinMessage>,
    /// Control channel
    control_tx: mpsc::Sender<ControlMessage>,
    /// Metrics collector
    metrics: MetricsCollector,
    /// Running state
    is_running: bool,
}

impl OdinProtocol {
    /// Create a new ODIN Protocol instance
    pub fn new(config: OdinConfig) -> Result<Self> {
        config.validate()?;
        
        let (message_tx, message_rx) = broadcast::channel(1024);
        let (control_tx, _control_rx) = mpsc::channel(256);
        let metrics = MetricsCollector::new();
        
        Ok(Self {
            node_id: config.node_id.clone(),
            config,
            connections: HashMap::new(),
            message_tx,
            message_rx,
            control_tx,
            metrics,
            is_running: false,
        })
    }
    
    /// Start the protocol instance
    pub async fn start(&mut self) -> Result<()> {
        if self.is_running {
            return Err(OdinError::Protocol("Protocol already running".to_string()));
        }
        
        self.is_running = true;
        self.metrics.record_startup();
        
        // Initialize network connections
        self.initialize_network().await?;
        
        // Start heartbeat
        self.start_heartbeat().await?;
        
        Ok(())
    }
    
    /// Stop the protocol instance
    pub async fn stop(&mut self) -> Result<()> {
        if !self.is_running {
            return Ok(());
        }
        
        self.is_running = false;
        
        // Close all connections
        for (_, mut connection) in self.connections.drain() {
            connection.close().await?;
        }
        
        self.metrics.record_shutdown();
        Ok(())
    }
    
    /// Send a message to a specific node
    pub async fn send_message(&self, target_node: &str, content: &str, priority: MessagePriority) -> Result<String> {
        if !self.is_running {
            return Err(OdinError::Protocol("Protocol not running".to_string()));
        }
        
        let message = OdinMessage::new(
            MessageType::Standard,
            &self.node_id,
            target_node,
            content,
            priority,
        );
        
        self.metrics.record_message_sent();
        
        // Send through broadcast channel
        self.message_tx.send(message.clone()).map_err(|e| {
            OdinError::Network(format!("Failed to send message: {}", e))
        })?;
        
        Ok(message.id.clone())
    }
    
    /// Broadcast a message to all connected nodes
    pub async fn broadcast_message(&self, content: &str, priority: MessagePriority) -> Result<String> {
        if !self.is_running {
            return Err(OdinError::Protocol("Protocol not running".to_string()));
        }
        
        let message = OdinMessage::new(
            MessageType::Broadcast,
            &self.node_id,
            "all",
            content,
            priority,
        );
        
        self.metrics.record_broadcast_sent();
        
        self.message_tx.send(message.clone()).map_err(|e| {
            OdinError::Network(format!("Failed to broadcast message: {}", e))
        })?;
        
        Ok(message.id.clone())
    }
    
    /// Subscribe to messages
    pub fn subscribe_to_messages(&self) -> broadcast::Receiver<OdinMessage> {
        self.message_tx.subscribe()
    }
    
    /// Get protocol metrics
    pub fn get_metrics(&self) -> HashMap<String, f64> {
        self.metrics.get_metrics()
    }
    
    /// Get node status
    pub fn get_status(&self) -> NodeStatus {
        NodeStatus {
            node_id: self.node_id.clone(),
            is_running: self.is_running,
            connection_count: self.connections.len(),
            uptime: self.metrics.get_uptime(),
            messages_sent: self.metrics.get_messages_sent(),
            messages_received: self.metrics.get_messages_received(),
        }
    }
    
    /// Initialize network connections
    async fn initialize_network(&mut self) -> Result<()> {
        // TODO: Implement actual network connection logic
        // For now, create a mock connection
        let connection = Connection::new(&self.config.network_endpoint).await?;
        self.connections.insert("default".to_string(), connection);
        Ok(())
    }
    
    /// Start heartbeat mechanism
    async fn start_heartbeat(&self) -> Result<()> {
        let interval = self.config.heartbeat_interval;
        let tx = self.message_tx.clone();
        let node_id = self.node_id.clone();
        
        tokio::spawn(async move {
            let mut interval_timer = tokio::time::interval(interval);
            
            loop {
                interval_timer.tick().await;
                
                let heartbeat = OdinMessage::new(
                    MessageType::Heartbeat,
                    &node_id,
                    "all",
                    "heartbeat",
                    MessagePriority::Low,
                );
                
                if tx.send(heartbeat).is_err() {
                    break; // Channel closed, stop heartbeat
                }
            }
        });
        
        Ok(())
    }
}

/// Network connection wrapper
#[derive(Debug)]
pub struct Connection {
    endpoint: String,
    is_connected: bool,
}

impl Connection {
    /// Create a new connection
    pub async fn new(endpoint: &str) -> Result<Self> {
        // TODO: Implement actual WebSocket connection
        Ok(Self {
            endpoint: endpoint.to_string(),
            is_connected: true,
        })
    }
    
    /// Close the connection
    pub async fn close(&mut self) -> Result<()> {
        self.is_connected = false;
        Ok(())
    }
}

/// Control messages for internal protocol management
#[derive(Debug, Clone)]
pub enum ControlMessage {
    Connect(String),
    Disconnect(String),
    Shutdown,
}

/// Node status information
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct NodeStatus {
    pub node_id: String,
    pub is_running: bool,
    pub connection_count: usize,
    pub uptime: f64,
    pub messages_sent: u64,
    pub messages_received: u64,
}

/// Trait for protocol handlers
#[async_trait]
pub trait ProtocolHandler: Send + Sync {
    /// Handle incoming message
    async fn handle_message(&self, message: &OdinMessage) -> Result<Option<OdinMessage>>;
    
    /// Handle connection events
    async fn handle_connection_event(&self, event: ConnectionEvent) -> Result<()>;
}

/// Connection events
#[derive(Debug, Clone)]
pub enum ConnectionEvent {
    Connected(String),
    Disconnected(String),
    Error(String, String),
}

#[cfg(test)]
mod tests {
    use super::*;
    use crate::config::OdinConfig;
    use tokio::time::{timeout, Duration};
    
    #[tokio::test]
    async fn test_protocol_creation() {
        let config = OdinConfig::default();
        let protocol = OdinProtocol::new(config).unwrap();
        
        assert!(!protocol.is_running);
        assert_eq!(protocol.connections.len(), 0);
    }
    
    #[tokio::test]
    async fn test_message_sending() {
        let config = OdinConfig::default();
        let mut protocol = OdinProtocol::new(config).unwrap();
        
        protocol.start().await.unwrap();
        
        let message_id = protocol
            .send_message("target-node", "test message", MessagePriority::Normal)
            .await
            .unwrap();
            
        assert!(!message_id.is_empty());
        
        protocol.stop().await.unwrap();
    }
    
    #[tokio::test]
    async fn test_message_subscription() {
        let config = OdinConfig::default();
        let mut protocol = OdinProtocol::new(config).unwrap();
        
        protocol.start().await.unwrap();
        
        let mut rx = protocol.subscribe_to_messages();
        
        // Send a message
        protocol
            .send_message("target-node", "test message", MessagePriority::Normal)
            .await
            .unwrap();
        
        // Receive the message
        let received = timeout(Duration::from_millis(100), rx.recv()).await;
        assert!(received.is_ok());
        
        let message = received.unwrap().unwrap();
        assert_eq!(message.content, "test message");
        assert_eq!(message.target_node, "target-node");
        
        protocol.stop().await.unwrap();
    }
    
    #[tokio::test]
    async fn test_protocol_status() {
        let config = OdinConfig::default();
        let protocol = OdinProtocol::new(config).unwrap();
        
        let status = protocol.get_status();
        assert!(!status.is_running);
        assert_eq!(status.connection_count, 0);
        assert_eq!(status.messages_sent, 0);
    }
}