#!/usr/bin/env bash
# Liveness check for the CoAP server. Exits 0 if healthy, 1 if not.
#   ./healthcheck.sh          quiet, for cron/systemd/monitoring
#   ./healthcheck.sh -v       print what it found
# Retargets with COAP_HOST / COAP_PORT.

CLIENT=${CLIENT:-$(dirname "$0")/target/release/client}
verbose=false; [[ $1 == -v ]] && verbose=true
say() { $verbose && echo "$@"; }

host=${COAP_HOST:-127.0.0.1}; port=${COAP_PORT:-5683}

[[ -x $CLIENT ]] || { echo "healthcheck: no client binary at $CLIENT (cargo build --release)"; exit 1; }

reply=$("$CLIENT" get /health 2>&1)

# A bound socket proves nothing on UDP - the round trip is the real test.
if [[ $reply != "<- 2.05 "* ]]; then
  echo "UNHEALTHY: coap://$host:$port/health -> ${reply:-no reply}"
  exit 1
fi

body=${reply#<- 2.05 }
if [[ $body != *'"status":"ok"'* ]]; then
  echo "UNHEALTHY: unexpected body from coap://$host:$port/health -> $body"
  exit 1
fi

uptime=$(sed -n 's/.*"uptime":\([0-9]*\).*/\1/p' <<<"$body")
say "HEALTHY: coap://$host:$port up ${uptime}s (code 2.05)"
exit 0