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

SELF_DIR="$(cd "$(dirname "$0")" && pwd)"
INSTALL_TAG="${INSTALL_TAG:-neko-ip-watch}"
. "$SELF_DIR/lib/common.sh"

reload_watch_env() {
  unset ENABLE_NEKO NEKO_IP_WATCH_INTERVAL
  if [ -f "$STACK_ENV" ]; then
    set -a
    . "$STACK_ENV"
    set +a
  fi
  ENABLE_NEKO="${ENABLE_NEKO:-1}"
  NEKO_IP_WATCH_INTERVAL="${NEKO_IP_WATCH_INTERVAL:-15}"
}

normalize_interval() {
  local value="${1:-15}"
  case "$value" in
    ''|*[!0-9]*)
      value=15
      ;;
  esac
  if [ "$value" -lt 5 ]; then
    value=5
  fi
  printf '%s\n' "$value"
}

running_neko_nat1to1_values() {
  local name value
  docker ps --format '{{.Names}}' 2>/dev/null | grep -E '^live-neko-[0-9]+$' | sort -V | while read -r name; do
    [ -n "$name" ] || continue
    value="$(
      docker inspect "$name" --format '{{range .Config.Env}}{{println .}}{{end}}' 2>/dev/null |
        awk -F= '/^NEKO_WEBRTC_NAT1TO1=/{print $2; exit}'
    )"
    if [ -n "$value" ]; then
      printf '%s\n' "$value"
    fi
  done
}

maybe_refresh_neko_for_ip_change() {
  local preferred active interval cooldown active_value

  if [ "${ENABLE_NEKO:-1}" != "1" ] || ! have docker; then
    return 0
  fi
  if ! docker ps --format '{{.Names}}' 2>/dev/null | grep -Eq '^live-neko-[0-9]+$'; then
    return 0
  fi

  preferred="$(detect_preferred_lan_ip || true)"
  if [ -z "$preferred" ]; then
    return 0
  fi

  active=""
  for active_value in $(running_neko_nat1to1_values || true); do
    [ -n "$active_value" ] || continue
    if [ "$active_value" != "$preferred" ]; then
      active="$active_value"
      break
    fi
  done
  if [ -z "$active" ]; then
    return 0
  fi

  interval="$(normalize_interval "${NEKO_IP_WATCH_INTERVAL:-15}")"
  cooldown="$interval"
  if [ "$cooldown" -lt 15 ]; then
    cooldown=15
  fi

  log "Detected Neko LAN IP drift: container=${active} current=${preferred}; restarting Neko"
  if bash "$SERVICE_CTL" neko restart; then
    log "Neko restart finished; refreshed NAT1TO1=${preferred}"
  else
    log "WARN: Neko restart failed after LAN IP drift"
  fi
  sleep "$cooldown"
}

main() {
  load_env
  reload_watch_env
  log "Watching Neko LAN IP changes"
  while true; do
    reload_watch_env
    maybe_refresh_neko_for_ip_change
    sleep "$(normalize_interval "${NEKO_IP_WATCH_INTERVAL:-15}")"
  done
}

main "$@"