#!/bin/sh
# healthcheck.sh — RouterOS container health check for mdns-reflector
#
# Returns 0 (healthy) if:
#   1. Health file exists and is younger than 30 seconds
#   2. mdns-repeater process is running
#   3. At least one interface socket is alive
#
# Returns 1 (unhealthy) otherwise.

HEALTH_FILE="/tmp/mdns-health"

# 1. Check health file exists
if [ ! -f "$HEALTH_FILE" ]; then
    echo "unhealthy: no health file"
    exit 1
fi

# 2. Check health file freshness (must be < 30s old)
now=$(date +%s)
file_ts=$(awk -F= '/^ts=/{print $2}' "$HEALTH_FILE" 2>/dev/null)
if [ -z "$file_ts" ]; then
    echo "unhealthy: no timestamp in health file"
    exit 1
fi

age=$((now - file_ts))
if [ "$age" -gt 30 ]; then
    echo "unhealthy: health file stale (${age}s old)"
    exit 1
fi

# 3. Check process is running
pid=$(pidof mdns-repeater 2>/dev/null)
if [ -z "$pid" ]; then
    echo "unhealthy: mdns-repeater not running"
    exit 1
fi

# 4. Check at least one interface has a socket (fd4 or fd6 open)
n_ifaces=$(awk -F= '/^n_ifaces=/ {print $2}' "$HEALTH_FILE" 2>/dev/null)
if [ -z "$n_ifaces" ] || [ "$n_ifaces" -eq 0 ]; then
    echo "unhealthy: no interfaces configured"
    exit 1
fi

# 5. Verify sockets are actually bound to port 5353
ss -lupn 2>/dev/null | grep -q ":5353"
if [ $? -ne 0 ]; then
    echo "unhealthy: no UDP socket on port 5353"
    exit 1
fi

echo "healthy: ${n_ifaces} interfaces, age=${age}s"
exit 0