//! Heartbeat and TTL management
//!
//! Keeps sessions alive through cooperative heartbeats.

const std = @import("std");
const Session = @import("session.zig").Session;

/// Heartbeat manager
pub const Heartbeat = struct {
    /// Send a heartbeat to the peer
    pub fn send(session: *Session, ctx: anytype) !void {
        // TODO: Implement heartbeat sending
        _ = session;
        _ = ctx;
    }
    
    /// Process received heartbeat
    pub fn receive(session: *Session, ctx: anytype) !void {
        // TODO: Update last_activity, reset missed count
        _ = session;
        _ = ctx;
    }
    
    /// Check if heartbeat is due
    pub fn isDue(session: *Session, now: i64) bool {
        const elapsed = now - session.last_activity;
        return elapsed >= session.config.heartbeat_interval.seconds();
    }
    
    /// Handle missed heartbeat
    pub fn handleMissed(session: *Session) void {
        session.missed_heartbeats += 1;
        
        if (session.missed_heartbeats >= session.config.heartbeat_tolerance) {
            // Transition to degraded state
            session.state = .degraded;
        }
    }
};