#!/usr/bin/env bash
set -euo pipefail

# Simple TCP healthcheck against the first server in NATS_SERVERS
# Accepts schemes nats:// or tls://
first_server=$(awk '{print $1}' <<< "${NATS_SERVERS:-}")
if [[ -z "${first_server}" ]]; then
  echo "NATS_SERVERS not set" >&2
  exit 1
fi

# Extract host and port
scheme="${first_server%%://*}"
rest="${first_server#*://}"

host="${rest%:*}"
port="${rest##*:}"

# If rest still contains '/', strip path
host="${host%%/*}"
port="${port%%/*}"

: "${port:=4222}"

# Try TCP connect (bash /dev/tcp)
timeout 3 bash -c "cat < /dev/null > /dev/tcp/${host}/${port}" 2>/dev/null || {
  echo "Cannot connect to ${host}:${port}" >&2
  exit 1
}

# Optionally add more checks later (e.g., NATS /varz on 8222)
exit 0