#!/usr/bin/env bash
# Passive monitor for a misbehaving unit.  Every INTERVAL seconds, attempts
# a single short TCP probe + storage_range read and logs the result.  Designed
# to run unattended for hours/days and tell you when the unit comes back.
#
# Usage:
#   ./watch_unit.sh <host> [tcp_port]
#
# Env:
#   INTERVAL    Seconds between checks (default 300 = 5 min)
#   LOG_FILE    Append results here (default /tmp/watch_<host>.log)
#   SFM_BASE_URL  Default: http://localhost:8200

set -u

host="${1:-}"
tcp_port="${2:-9034}"
if [[ -z "$host" ]]; then
  echo "usage: $0 <host> [tcp_port]" >&2
  exit 2
fi

interval="${INTERVAL:-300}"
log_file="${LOG_FILE:-/tmp/watch_${host}.log}"
base="${SFM_BASE_URL:-http://localhost:8200}"

url="${base}/device/events/storage_range?host=${host}&tcp_port=${tcp_port}"

echo "watch_unit: target ${host}:${tcp_port}  interval=${interval}s  log=${log_file}"
echo "watch_unit: Ctrl-C to stop"

while true; do
  ts=$(date '+%Y-%m-%d %H:%M:%S')
  http_code=$(curl -sS -o /tmp/watch_resp.$$ -w "%{http_code}" \
    --max-time 20 "$url" || echo "000")
  body=$(cat /tmp/watch_resp.$$ 2>/dev/null || true)
  rm -f /tmp/watch_resp.$$

  case "$http_code" in
    200|201)
      # Strip the raw_hex for readability
      summary=$(echo "$body" | sed 's/"raw_hex":"[^"]*",*//; s/,*$//' | head -c 200)
      echo "$ts  REACHABLE  $summary" | tee -a "$log_file"
      ;;
    502|503)
      err=$(echo "$body" | head -c 150)
      echo "$ts  ERROR_$http_code  $err" | tee -a "$log_file"
      ;;
    000)
      echo "$ts  CURL_FAIL  (network/timeout)" | tee -a "$log_file"
      ;;
    *)
      echo "$ts  HTTP_$http_code  $(echo "$body" | head -c 150)" | tee -a "$log_file"
      ;;
  esac

  sleep "$interval"
done