kiteticker-async-manager 0.4.0

use crate::manager::{ConnectionStats, ManagerStats};
use std::sync::Arc;
use std::time::{Duration, Instant};
use tokio::sync::RwLock;
use tokio::task::JoinHandle;
use tokio::time::sleep;

/// Health monitor for tracking connection and system health
#[derive(Debug)]
pub struct HealthMonitor {
  pub connection_stats: Vec<Arc<RwLock<ConnectionStats>>>,
  pub manager_start_time: Instant,
  pub monitoring_task: Option<JoinHandle<()>>,
  pub health_check_interval: Duration,
}

impl HealthMonitor {
  /// Create a new health monitor
  pub fn new(
    connection_stats: Vec<Arc<RwLock<ConnectionStats>>>,
    health_check_interval: Duration,
  ) -> Self {
    Self {
      connection_stats,
      manager_start_time: Instant::now(),
      monitoring_task: None,
      health_check_interval,
    }
  }

  /// Start the health monitoring task
  pub fn start(&mut self) {
    let connection_stats = self.connection_stats.clone();
    let health_check_interval = self.health_check_interval;
    let manager_start_time = self.manager_start_time;

    let handle = tokio::spawn(async move {
      Self::monitoring_loop(
        connection_stats,
        health_check_interval,
        manager_start_time,
      )
      .await;
    });

    self.monitoring_task = Some(handle);
  }

  /// Health monitoring loop
  async fn monitoring_loop(
    connection_stats: Vec<Arc<RwLock<ConnectionStats>>>,
    health_check_interval: Duration,
    manager_start_time: Instant,
  ) {
    log::info!(
      "Health monitor started with interval: {:?}",
      health_check_interval
    );

    loop {
      sleep(health_check_interval).await;

      // Collect health information
      let mut healthy_connections = 0;
      let mut total_symbols = 0;
      let mut total_messages = 0;
      let mut total_errors = 0;

      for (i, stats_arc) in connection_stats.iter().enumerate() {
        let mut stats = stats_arc.write().await;

        // Update connection uptime
        if stats.is_connected {
          stats.connection_uptime = manager_start_time.elapsed();
          healthy_connections += 1;
        }

        total_symbols += stats.symbol_count;
        total_messages += stats.messages_received;
        total_errors += stats.errors_count;

        // Log individual connection health
        log::debug!(
          "Connection {}: healthy={}, symbols={}, messages={}, errors={}",
          i,
          stats.is_connected,
          stats.symbol_count,
          stats.messages_received,
          stats.errors_count
        );
      }

      // Log overall health
      log::info!(
                "Health Check: {}/{} connections healthy, {} total symbols, {} messages, {} errors",
                healthy_connections,
                connection_stats.len(),
                total_symbols,
                total_messages,
                total_errors
            );

      // Alert on issues
      if healthy_connections == 0 {
        log::error!("CRITICAL: All connections are unhealthy!");
      } else if healthy_connections < connection_stats.len() {
        log::warn!(
          "WARNING: {}/{} connections are unhealthy",
          connection_stats.len() - healthy_connections,
          connection_stats.len()
        );
      }
    }
  }

  /// Get comprehensive manager statistics
  pub async fn get_manager_stats(&self) -> ManagerStats {
    let mut manager_stats = ManagerStats {
      uptime: self.manager_start_time.elapsed(),
      ..Default::default()
    };

    let mut active_connections = 0;

    for stats_arc in &self.connection_stats {
      let stats = stats_arc.read().await;

      if stats.is_connected {
        active_connections += 1;
      }

      manager_stats.total_symbols += stats.symbol_count;
      manager_stats.total_messages_received += stats.messages_received;
      manager_stats.total_errors += stats.errors_count;
      manager_stats.connection_stats.push(stats.clone());
    }

    manager_stats.active_connections = active_connections;
    manager_stats
  }

  /// Get health summary
  pub async fn get_health_summary(&self) -> HealthSummary {
    let mut summary = HealthSummary::default();

    for (i, stats_arc) in self.connection_stats.iter().enumerate() {
      let stats = stats_arc.read().await;

      if stats.is_connected {
        summary.healthy_connections += 1;
      } else {
        summary.unhealthy_connections.push(i);
      }

      summary.total_symbols += stats.symbol_count;
      summary.total_messages += stats.messages_received;
      summary.total_errors += stats.errors_count;

      // Calculate message rate (messages per second over last minute)
      if let Some(last_msg_time) = stats.last_message_time {
        if last_msg_time.elapsed() < Duration::from_secs(60) {
          summary.active_message_flows += 1;
        }
      }
    }

    summary.uptime = self.manager_start_time.elapsed();
    summary
  }

  /// Stop the health monitor
  pub async fn stop(&mut self) {
    if let Some(handle) = self.monitoring_task.take() {
      handle.abort();
      let _ = handle.await;
    }
  }
}

/// Health summary for quick status checks
#[derive(Debug, Clone, Default)]
pub struct HealthSummary {
  pub healthy_connections: usize,
  pub unhealthy_connections: Vec<usize>,
  pub total_symbols: usize,
  pub total_messages: u64,
  pub total_errors: u64,
  pub active_message_flows: usize,
  pub uptime: Duration,
}

impl HealthSummary {
  /// Check if the system is healthy
  pub fn is_healthy(&self) -> bool {
    self.unhealthy_connections.is_empty() && self.total_errors == 0
  }

  /// Check if the system is degraded (some connections unhealthy)
  pub fn is_degraded(&self) -> bool {
    !self.unhealthy_connections.is_empty() && self.healthy_connections > 0
  }

  /// Check if the system is critical (all connections unhealthy)
  pub fn is_critical(&self) -> bool {
    self.healthy_connections == 0
  }

  /// Get health percentage (0-100)
  pub fn health_percentage(&self) -> f64 {
    let total_connections =
      self.healthy_connections + self.unhealthy_connections.len();
    if total_connections == 0 {
      100.0
    } else {
      (self.healthy_connections as f64 / total_connections as f64) * 100.0
    }
  }
}