#!/bin/bash
# =============================================================================
# uninstall-snmpsim-lab.sh
#
# Completely removes the SevOne SNMP Simulation Lab.
#
# Usage:
#   sudo ./uninstall-snmpsim-lab.sh [OPTIONS]
#
# Options:
#   --yes              Skip confirmation prompt
#   --keep-pip         Keep the snmpsim pip package installed
#   --keep-user        Keep the snmpsim system user
#   -h, --help         Show this help
# =============================================================================

set -euo pipefail

INSTALL_DIR="/opt/snmpsim"
SNMPSIM_USER="snmpsim"
PID_DIR="/var/run/snmpsim.commands.responder"
CACHE_DIR="/tmp/snmpsim"

SERVICES=(
  "snmpsim-agents.service"
  "snmpsim-netflow.service"
  "snmpsim-traps.timer"
  "snmpsim-traps.service"
)

SERVICE_FILES=(
  "/etc/systemd/system/snmpsim-agents.service"
  "/etc/systemd/system/snmpsim-netflow.service"
  "/etc/systemd/system/snmpsim-traps.service"
  "/etc/systemd/system/snmpsim-traps.timer"
)

# ── Colours ───────────────────────────────────────────────────────────────────
RED='\033[0;31m'
GREEN='\033[0;32m'
YELLOW='\033[1;33m'
BLUE='\033[0;34m'
CYAN='\033[0;36m'
NC='\033[0m'

info()    { echo -e "${CYAN}[INFO]${NC}  $*"; }
ok()      { echo -e "${GREEN}[OK]${NC}    $*"; }
skip()    { echo -e "${YELLOW}[SKIP]${NC}  $*"; }
section() { echo -e "\n${BLUE}══════════════════════════════════════════${NC}";
            echo -e "${BLUE}  $*${NC}";
            echo -e "${BLUE}══════════════════════════════════════════${NC}"; }

# ── Must run as root ──────────────────────────────────────────────────────────
if [[ $EUID -ne 0 ]]; then
  echo -e "${RED}[ERROR]${NC} This script must be run as root (sudo)"
  exit 1
fi

# ── Usage ─────────────────────────────────────────────────────────────────────
usage() {
  cat << EOF

Usage: $(basename "$0") [OPTIONS]

OPTIONS:
  --yes          Skip confirmation prompt
  --keep-pip     Keep the snmpsim pip package installed
  --keep-user    Keep the snmpsim system user
  -h, --help     Show this help

EXAMPLES:
  sudo $(basename "$0")                        # Full uninstall with prompt
  sudo $(basename "$0") --yes                  # Full uninstall, no prompt
  sudo $(basename "$0") --keep-pip --keep-user # Remove lab files only

EOF
  exit 0
}

# ── Parse arguments ───────────────────────────────────────────────────────────
SKIP_CONFIRM=0
KEEP_PIP=0
KEEP_USER=0

for arg in "$@"; do
  case "$arg" in
    --yes|-y)        SKIP_CONFIRM=1 ;;
    --keep-pip)      KEEP_PIP=1 ;;
    --keep-user)     KEEP_USER=1 ;;
    -h|--help)       usage ;;
    *) echo -e "${RED}[ERROR]${NC} Unknown option: $arg"; usage ;;
  esac
done

# ── Confirmation ──────────────────────────────────────────────────────────────
echo ""
echo -e "${RED}╔══════════════════════════════════════════════════╗${NC}"
echo -e "${RED}║    SevOne SNMP Lab Uninstaller                   ║${NC}"
echo -e "${RED}╚══════════════════════════════════════════════════╝${NC}"
echo ""
echo -e "  Will remove:"
echo -e "    ${CYAN}${INSTALL_DIR}/${NC}             (all data, scripts, binaries)"
echo -e "    ${CYAN}systemd services${NC}             (snmpsim-agents, netflow, traps)"
echo -e "    ${CYAN}${PID_DIR}/${NC}"
echo -e "    ${CYAN}${CACHE_DIR}/${NC}"

if [[ $KEEP_PIP -eq 0 ]]; then
  echo -e "    ${CYAN}snmpsim pip package${NC}"
else
  echo -e "    ${YELLOW}snmpsim pip package${NC}          (keeping -- --keep-pip)"
fi

if [[ $KEEP_USER -eq 0 ]]; then
  echo -e "    ${CYAN}snmpsim system user${NC}"
else
  echo -e "    ${YELLOW}snmpsim system user${NC}          (keeping -- --keep-user)"
fi

echo ""

if [[ $SKIP_CONFIRM -eq 0 ]]; then
  read -rp "Are you sure you want to uninstall? [y/N] " CONFIRM
  [[ "$CONFIRM" =~ ^[Yy]$ ]] || { echo "Aborted."; exit 0; }
fi

# ─────────────────────────────────────────────────────────────────────────────
section "Step 1: Stop and disable systemd services"
# ─────────────────────────────────────────────────────────────────────────────

for svc in "${SERVICES[@]}"; do
  if systemctl is-active --quiet "$svc" 2>/dev/null; then
    systemctl stop "$svc"
    ok "Stopped: $svc"
  else
    skip "Not running: $svc"
  fi

  if systemctl is-enabled --quiet "$svc" 2>/dev/null; then
    systemctl disable "$svc"
    ok "Disabled: $svc"
  else
    skip "Not enabled: $svc"
  fi
done

# ─────────────────────────────────────────────────────────────────────────────
section "Step 2: Kill any remaining processes"
# ─────────────────────────────────────────────────────────────────────────────

if pgrep -f snmpsim-command-responder &>/dev/null; then
  pkill -f snmpsim-command-responder
  ok "Killed remaining snmpsim processes"
else
  skip "No snmpsim processes running"
fi

if pgrep -f nflow-generator &>/dev/null; then
  pkill -f nflow-generator
  ok "Killed nflow-generator process"
else
  skip "No nflow-generator process running"
fi

# ─────────────────────────────────────────────────────────────────────────────
section "Step 3: Remove systemd unit files"
# ─────────────────────────────────────────────────────────────────────────────

for f in "${SERVICE_FILES[@]}"; do
  if [[ -f "$f" ]]; then
    rm -f "$f"
    ok "Removed: $f"
  else
    skip "Not found: $f"
  fi
done

systemctl daemon-reload
ok "systemd daemon reloaded"

# ─────────────────────────────────────────────────────────────────────────────
section "Step 4: Remove install directory"
# ─────────────────────────────────────────────────────────────────────────────

if [[ -d "$INSTALL_DIR" ]]; then
  rm -rf "$INSTALL_DIR"
  ok "Removed: $INSTALL_DIR"
else
  skip "Not found: $INSTALL_DIR"
fi

# ─────────────────────────────────────────────────────────────────────────────
section "Step 5: Remove PID directory and cache"
# ─────────────────────────────────────────────────────────────────────────────

if [[ -d "$PID_DIR" ]]; then
  rm -rf "$PID_DIR"
  ok "Removed: $PID_DIR"
else
  skip "Not found: $PID_DIR"
fi

if [[ -d "$CACHE_DIR" ]]; then
  rm -rf "$CACHE_DIR"
  ok "Removed: $CACHE_DIR"
else
  skip "Not found: $CACHE_DIR"
fi

# ─────────────────────────────────────────────────────────────────────────────
section "Step 6: snmpsim pip package"
# ─────────────────────────────────────────────────────────────────────────────

if [[ $KEEP_PIP -eq 1 ]]; then
  skip "Keeping snmpsim pip package (--keep-pip)"
else
  if pip3 show snmpsim-lextudio &>/dev/null 2>&1; then
    pip3 uninstall -y snmpsim-lextudio
    ok "Uninstalled: snmpsim-lextudio"
  elif pip3 show snmpsim &>/dev/null 2>&1; then
    pip3 uninstall -y snmpsim
    ok "Uninstalled: snmpsim"
  else
    skip "snmpsim pip package not found"
  fi

  # Remove leftover snmpsim binaries
  for bin in snmpsim-command-responder snmpsim-record-mibs; do
    path=$(command -v "$bin" 2>/dev/null || true)
    if [[ -n "$path" ]]; then
      rm -f "$path"
      ok "Removed binary: $path"
    fi
  done
fi

# ─────────────────────────────────────────────────────────────────────────────
section "Step 7: snmpsim system user"
# ─────────────────────────────────────────────────────────────────────────────

if [[ $KEEP_USER -eq 1 ]]; then
  skip "Keeping snmpsim user (--keep-user)"
else
  if id "$SNMPSIM_USER" &>/dev/null; then
    userdel "$SNMPSIM_USER"
    ok "Removed user: $SNMPSIM_USER"
  else
    skip "User not found: $SNMPSIM_USER"
  fi
fi

# ─────────────────────────────────────────────────────────────────────────────
section "Step 8: Remove cron entries (if any)"
# ─────────────────────────────────────────────────────────────────────────────

if crontab -l 2>/dev/null | grep -q "trap-generator"; then
  crontab -l 2>/dev/null | grep -v "trap-generator" | crontab -
  ok "Removed trap-generator cron entry"
else
  skip "No trap-generator cron entry found"
fi

# ─────────────────────────────────────────────────────────────────────────────
# Done
# ─────────────────────────────────────────────────────────────────────────────
echo ""
echo -e "${GREEN}╔══════════════════════════════════════════════════╗${NC}"
echo -e "${GREEN}║  Uninstall complete                              ║${NC}"
echo -e "${GREEN}╚══════════════════════════════════════════════════╝${NC}"
echo ""

KEPT=()
[[ $KEEP_PIP  -eq 1 ]] && KEPT+=("snmpsim pip package")
[[ $KEEP_USER -eq 1 ]] && KEPT+=("snmpsim system user")

if [[ ${#KEPT[@]} -gt 0 ]]; then
  echo -e "  Kept (by request):"
  for item in "${KEPT[@]}"; do
    echo -e "    ${YELLOW}${item}${NC}"
  done
  echo ""
fi

echo -e "  Not removed (system packages):"
echo -e "    Python 3, pip, Go, git, net-snmp-utils"
echo ""
echo -e "  Ready for a fresh install:"
echo -e "    ${CYAN}sudo ./install-snmpsim-lab.sh --vm-ip <IP> --trap-host <IP> --netflow-host <IP>${NC}"
echo ""