#!/bin/bash
# Setup NUT client on a Proxmox slave node.
# Usage:
#   ./setup-nut-slave.sh <MASTER_IP> [UPS_NAME] [NUT_USER] [NUT_PASS]
#
# Example:
#   ./setup-nut-slave.sh 192.168.1.10 cyberpower remote remotepass
#
# MASTER_IP  = IP of the NUT master (the host with the USB UPS)
# UPS_NAME   = NUT UPS name defined on the master (default: cyberpower)
# NUT_USER   = user defined in /etc/nut/upsd.users on master (default: remote)
# NUT_PASS   = that user's password (default: remotepass)

set -euo pipefail

MASTER_IP="${1:-}"
UPS_NAME="${2:-cyberpower}"
NUT_USER="${3:-remote}"
NUT_PASS="${4:-remotepass}"

NUT_CONF="/etc/nut/nut.conf"
UPSMON_CONF="/etc/nut/upsmon.conf"

if [[ -z "${MASTER_IP}" ]]; then
  echo "Usage: $0 <MASTER_IP> [UPS_NAME] [NUT_USER] [NUT_PASS]"
  exit 1
fi

if [[ "$(id -u)" -ne 0 ]]; then
  echo "This script must be run as root."
  exit 1
fi

echo "=== NUT slave setup on Proxmox node ==="
echo "Master IP : ${MASTER_IP}"
echo "UPS name  : ${UPS_NAME}"
echo "NUT user  : ${NUT_USER}"

install_nut_client() {
  echo
  echo ">>> Installing NUT client..."
  apt-get update -y
  apt-get install -y nut-client
}

configure_nut_mode() {
  echo
  echo ">>> Configuring NUT mode (netclient) in ${NUT_CONF}..."
  if [[ -f "${NUT_CONF}" ]]; then
    cp "${NUT_CONF}" "${NUT_CONF}.bak.$(date +%s)"
    echo "Backup created: ${NUT_CONF}.bak.*"
  fi

  cat > "${NUT_CONF}" <<EOF
# Generated by setup-nut-slave.sh
MODE=netclient
EOF
}

configure_upsmon() {
  echo
  echo ">>> Configuring upsmon in ${UPSMON_CONF}..."
  if [[ -f "${UPSMON_CONF}" ]]; then
    cp "${UPSMON_CONF}" "${UPSMON_CONF}.bak.$(date +%s)"
    echo "Backup created: ${UPSMON_CONF}.bak.*"
  fi

  cat > "${UPSMON_CONF}" <<EOF
# Generated by setup-nut-slave.sh

# Run as the 'nut' user (default on Debian/Proxmox)
RUN_AS_USER nut

# We only have one UPS to satisfy
MINSUPPLIES 1

# Proxmox-friendly shutdown command: this will stop VMs/CTs and power off the node
SHUTDOWNCMD "/sbin/poweroff"

# Flag file used by NUT to signal powerdown
POWERDOWNFLAG /etc/killpower

# This node is a SLAVE, connecting to the master NUT server
MONITOR ${UPS_NAME}@${MASTER_IP} 1 ${NUT_USER} ${NUT_PASS} slave

# Basic notifications
NOTIFYFLAG ONLINE   SYSLOG
NOTIFYFLAG ONBATT   SYSLOG+WALL
NOTIFYFLAG LOWBATT  SYSLOG+WALL
NOTIFYFLAG FSD      SYSLOG+WALL
NOTIFYFLAG COMMOK   SYSLOG
NOTIFYFLAG COMMBAD  SYSLOG+WALL
NOTIFYFLAG SHUTDOWN SYSLOG+WALL

# Notification messages (optional, defaults used if omitted)
# NOTIFYMSG ONLINE  "UPS ${UPS_NAME} on line power"
# NOTIFYMSG ONBATT  "UPS ${UPS_NAME} on battery"
# NOTIFYMSG LOWBATT "UPS ${UPS_NAME} low battery"
EOF
}

enable_services() {
  echo
  echo ">>> Enabling and restarting nut-client..."
  systemctl enable nut-client || true
  systemctl restart nut-client

  echo ">>> nut-client status:"
  systemctl --no-pager status nut-client || true
}

test_connectivity() {
  echo
  echo "=== TEST: NUT connectivity from this slave ==="

  echo
  echo "1) Testing raw UPS status from master with 'upsc'..."
  if command -v upsc >/dev/null 2>&1; then
    if upsc "${UPS_NAME}@${MASTER_IP}" ups.status 2>/dev/null; then
      echo "OK: Successfully queried UPS status from master."
    else
      echo "ERROR: Could not query UPS status from master."
      echo " - Check firewall between this node and ${MASTER_IP}:3493"
      echo " - Check that master has LISTEN 0.0.0.0 3493 in /etc/nut/upsd.conf"
      echo " - Check MONITOR user/password and UPS name."
    fi
  else
    echo "Command 'upsc' not found (should be installed with nut-client)."
  fi

  echo
  echo "2) Testing upsmon status locally..."
  if command -v upsmon >/dev/null 2>&1; then
    if upsmon -c status 2>/dev/null; then
      echo "OK: upsmon is running and sees the UPS."
    else
      echo "WARNING: upsmon status failed. Check /etc/nut/upsmon.conf and nut-client service."
    fi
  else
    echo "Command 'upsmon' not found."
  fi

  echo
  echo "3) OPTIONAL: Simulate a forced shutdown (fsd) test"
  echo "   This will cause this node to initiate a real shutdown if everything is wired correctly."
  echo "   ONLY do this if you're prepared for the node to go down."
  read -r -p "Run 'upsmon -c fsd' now on THIS NODE? [y/N]: " ans
  case "${ans}" in
    y|Y)
      echo ">>> Running 'upsmon -c fsd' (this may trigger a shutdown)..."
      upsmon -c fsd || echo "upsmon fsd command failed."
      ;;
    *)
      echo "Skipped FSD test."
      ;;
  esac
}

main() {
  install_nut_client
  configure_nut_mode
  configure_upsmon
  enable_services
  test_connectivity

  echo
  echo "=== Done. This Proxmox node is now configured as a NUT SLAVE. ==="
  echo "When the master detects LOWBATT, it will signal this node to shut down via upsmon."
  echo "Backups of original configs (if any) are in:"
  echo "  - ${NUT_CONF}.bak.*"
  echo "  - ${UPSMON_CONF}.bak.*"
}

main