#!/bin/bash
set -euo pipefail

SCRIPT_PATH="$(readlink -f "$0" 2>/dev/null || realpath "$0" 2>/dev/null || echo "$0")"
SCRIPTNAME="$(basename "$SCRIPT_PATH")"
LOCKFILE="/var/lock/${SCRIPTNAME}.pid"

# ========= Configuration =========
CONTAINER_NAME="paperless-ai"
OLLAMA_HOST="192.168.222.12"
OLLAMA_PORT="11434"
ERROR_PATTERN="Error: \[ERROR\] Document analysis failed: connect EHOSTUNREACH $OLLAMA_HOST:$OLLAMA_PORT"

# Tools (adjust if your distro uses different names)
WOL_CMD="wakeonlan"                               # or "etherwake -i eth0 $WOL_MAC"
NC_CMD="nc"                                       # netcat
DOCKER="docker"

log() { printf '[%(%F %T)T] %s\n' -1 "$*"; }

# --- Single-instance using PID lockfile in /var/lock ---
# Read old PID (if any) and terminate that instance if it is our script.
if [[ -f "$LOCKFILE" ]]; then
  oldpid="$(cat "$LOCKFILE" 2>/dev/null || true)"
  if [[ "${oldpid:-}" =~ ^[0-9]+$ ]] && kill -0 "$oldpid" 2>/dev/null; then
    # Optional sanity check: ensure the old PID is this same script (best-effort).
    if grep -qa "$SCRIPTNAME" "/proc/$oldpid/cmdline" 2>/dev/null; then
      log "Found running instance (pid=$oldpid) → terminating"
      kill "$oldpid" 2>/dev/null || true
      # Give it a short grace period, then force if still alive.
      for _ in 1 2 3; do
        sleep 1
        kill -0 "$oldpid" 2>/dev/null || break
      done
      kill -KILL "$oldpid" 2>/dev/null || true
    fi
  fi
fi

# Write our own PID to the lockfile (best-effort atomic via temp + move).
tmp_lock="${LOCKFILE}.$$"
printf '%d\n' "$$" > "$tmp_lock"
mv -f "$tmp_lock" "$LOCKFILE"

# Clean up lockfile on exit.
cleanup() {
  [[ -f "$LOCKFILE" ]] && [[ "$(cat "$LOCKFILE" 2>/dev/null || true)" == "$$" ]] && rm -f "$LOCKFILE" || true
}
trap cleanup EXIT INT TERM

# Follow container logs and look for the error pattern
"$DOCKER" logs -f --since 0s "$CONTAINER_NAME" 2>&1 | \
while IFS= read -r line; do
  # echo "$line"   # uncomment for debugging
  if echo "$line" | grep -qE "$ERROR_PATTERN"; then
    log "Detected EHOSTUNREACH for Ollama (${OLLAMA_HOST}:${OLLAMA_PORT})."
  fi
done