#!/bin/bash
# =============================================================================
# install-snmpsim-lab.sh
#
# Installs the SevOne SNMP Simulation Lab into /opt/snmpsim
# All 10 devices use SNMPv2c (community: public)
#
# Components:
#   - snmpsim-lextudio  : 10 faux Cisco SNMP agents
#   - trap-generator.sh : Random SNMP trap sender
#   - nflow-generator   : Synthetic NetFlow v5 exporter
#
# Usage:
#   ./install-snmpsim-lab.sh [OPTIONS]
#
# Options:
#   -v, --vm-ip        IP address of this VM (SNMP agents bind to this IP)
#   -t, --trap-host    IP address of the SNMP trap destination (SevOne)
#   -n, --netflow-host IP address of the NetFlow collector (SevOne)
#   -p, --netflow-port UDP port for NetFlow (default: 9996)
#   -T, --trap-port    UDP port for SNMP traps (default: 162)
#   -h, --help         Show this help message
#
# Example:
#   ./install-snmpsim-lab.sh \
#       --vm-ip 9.60.154.118 \
#       --trap-host 9.60.151.170 \
#       --netflow-host 9.60.151.170
#
# =============================================================================

set -euo pipefail

# ── Defaults ─────────────────────────────────────────────────────────────────
INSTALL_DIR="/opt/snmpsim"
SNMPSIM_USER="snmpsim"
NETFLOW_PORT="9996"
TRAP_PORT="162"
VM_IP=""
TRAP_HOST=""
NETFLOW_HOST=""

# ── Colours for output ────────────────────────────────────────────────────────
RED='\033[0;31m'
GREEN='\033[0;32m'
YELLOW='\033[1;33m'
BLUE='\033[0;34m'
CYAN='\033[0;36m'
NC='\033[0m' # No Colour

info()    { echo -e "${CYAN}[INFO]${NC}  $*"; }
ok()      { echo -e "${GREEN}[OK]${NC}    $*"; }
warn()    { echo -e "${YELLOW}[WARN]${NC}  $*"; }
error()   { echo -e "${RED}[ERROR]${NC} $*" >&2; }
section() { echo -e "\n${BLUE}══════════════════════════════════════════${NC}"; \
            echo -e "${BLUE}  $*${NC}"; \
            echo -e "${BLUE}══════════════════════════════════════════${NC}"; }

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

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

OPTIONS:
  -v, --vm-ip        IP address of this VM that SNMP agents will bind to  [REQUIRED]
  -t, --trap-host    Destination IP for SNMP traps (SevOne)               [REQUIRED]
  -n, --netflow-host Destination IP for NetFlow (SevOne)                  [REQUIRED]
  -p, --netflow-port UDP port for NetFlow collector (default: 9996)
  -T, --trap-port    UDP port for SNMP trap receiver (default: 162)
  -h, --help         Show this help

EXAMPLE:
  $(basename "$0") \\
      --vm-ip 9.60.154.118 \\
      --trap-host 9.60.151.170 \\
      --netflow-host 9.60.151.170

EOF
  exit 0
}

# ── Parse arguments ───────────────────────────────────────────────────────────
if [[ $# -eq 0 ]]; then usage; fi

while [[ $# -gt 0 ]]; do
  case "$1" in
    -v|--vm-ip)        VM_IP="$2";        shift 2 ;;
    -t|--trap-host)    TRAP_HOST="$2";    shift 2 ;;
    -n|--netflow-host) NETFLOW_HOST="$2"; shift 2 ;;
    -p|--netflow-port) NETFLOW_PORT="$2"; shift 2 ;;
    -T|--trap-port)    TRAP_PORT="$2";    shift 2 ;;
    -h|--help)         usage ;;
    *) error "Unknown option: $1"; usage ;;
  esac
done

# ── Validate required arguments ───────────────────────────────────────────────
MISSING=0
[[ -z "$VM_IP"        ]] && { error "--vm-ip is required";        MISSING=1; }
[[ -z "$TRAP_HOST"    ]] && { error "--trap-host is required";    MISSING=1; }
[[ -z "$NETFLOW_HOST" ]] && { error "--netflow-host is required"; MISSING=1; }
[[ $MISSING -eq 1 ]] && { echo ""; usage; }

# ── Must run as root ──────────────────────────────────────────────────────────
if [[ $EUID -ne 0 ]]; then
  error "This script must be run as root (sudo)"
  exit 1
fi

# ── Summary ───────────────────────────────────────────────────────────────────
echo ""
echo -e "${BLUE}╔══════════════════════════════════════════════════╗${NC}"
echo -e "${BLUE}║    SevOne SNMP Lab Installer                     ║${NC}"
echo -e "${BLUE}╚══════════════════════════════════════════════════╝${NC}"
echo ""
echo -e "  Install directory  : ${CYAN}${INSTALL_DIR}${NC}"
echo -e "  VM IP (SNMP bind)  : ${CYAN}${VM_IP}${NC}"
echo -e "  Trap destination   : ${CYAN}${TRAP_HOST}:${TRAP_PORT}${NC}"
echo -e "  NetFlow destination: ${CYAN}${NETFLOW_HOST}:${NETFLOW_PORT}${NC}"
echo ""
read -rp "Proceed with installation? [y/N] " CONFIRM
[[ "$CONFIRM" =~ ^[Yy]$ ]] || { echo "Aborted."; exit 0; }

# ─────────────────────────────────────────────────────────────────────────────
section "Step 1: System dependencies"
# ─────────────────────────────────────────────────────────────────────────────

# Detect package manager
if command -v apt-get &>/dev/null; then
  PKG_MGR="apt"
elif command -v dnf &>/dev/null; then
  PKG_MGR="dnf"
elif command -v yum &>/dev/null; then
  PKG_MGR="yum"
else
  error "Cannot detect package manager (apt/dnf/yum). Install dependencies manually."
  exit 1
fi

info "Package manager: $PKG_MGR"

install_pkg() {
  info "Installing: $*"
  case $PKG_MGR in
    apt) DEBIAN_FRONTEND=noninteractive NEEDRESTART_MODE=a apt-get install -y -qq -o Dpkg::Options::="--force-confdef" -o Dpkg::Options::="--force-confold" "$@" ;;
    dnf) dnf install -y "$@" -q ;;
    yum) yum install -y "$@" -q ;;
  esac
}

# Update package index
case $PKG_MGR in
  apt)
    DEBIAN_FRONTEND=noninteractive apt-get update -qq
    DEBIAN_FRONTEND=noninteractive NEEDRESTART_MODE=a apt-get upgrade -y -qq -o Dpkg::Options::="--force-confdef" -o Dpkg::Options::="--force-confold"
    ;;
  dnf|yum) : ;; # no-op, dnf/yum update on install
esac

# Core dependencies
install_pkg python3 python3-pip
install_pkg snmp snmp-mibs-downloader 2>/dev/null || install_pkg net-snmp-utils 2>/dev/null || \
  warn "Could not install net-snmp-utils — snmpwalk/snmptrap may be unavailable"
install_pkg git curl wget

# Go (for nflow-generator)
if ! command -v go &>/dev/null; then
  info "Installing Go..."
  case $PKG_MGR in
    apt) install_pkg golang-go ;;
    dnf|yum) install_pkg golang ;;
  esac
else
  ok "Go already installed: $(go version)"
fi

ok "System dependencies installed"

# ─────────────────────────────────────────────────────────────────────────────
section "Step 2: Create snmpsim user and directory structure"
# ─────────────────────────────────────────────────────────────────────────────

if id "$SNMPSIM_USER" &>/dev/null; then
  ok "User '$SNMPSIM_USER' already exists"
else
  useradd -r -s /sbin/nologin "$SNMPSIM_USER"
  ok "Created user: $SNMPSIM_USER"
fi

# Main directories
mkdir -p "${INSTALL_DIR}"/{data,logs,run}
for port in $(seq 10000 10009); do
  mkdir -p "${INSTALL_DIR}/data/port-${port}"
done

# PID file directory
mkdir -p /var/run/snmpsim.commands.responder

# Ownership
chown -R "${SNMPSIM_USER}:${SNMPSIM_USER}" "${INSTALL_DIR}"
chown "${SNMPSIM_USER}:${SNMPSIM_USER}" /var/run/snmpsim.commands.responder

ok "Directory structure created: ${INSTALL_DIR}"

# ─────────────────────────────────────────────────────────────────────────────
section "Step 3: Install snmpsim-lextudio"
# ─────────────────────────────────────────────────────────────────────────────

if command -v pip3 &>/dev/null; then
  pip3 install --quiet snmpsim
elif command -v pip &>/dev/null; then
  pip install --quiet snmpsim-lextudio
else
  error "pip not found. Cannot install snmpsim."
  exit 1
fi

# Find the installed binary
SNMPSIM_BIN=$(command -v snmpsim-command-responder 2>/dev/null || \
              find /usr /root ~/.local -name "snmpsim-command-responder" 2>/dev/null | head -1)

if [[ -z "$SNMPSIM_BIN" ]]; then
  error "snmpsim-command-responder not found after install. Check pip output above."
  exit 1
fi

ok "snmpsim installed: $SNMPSIM_BIN"

# ─────────────────────────────────────────────────────────────────────────────
section "Step 4: Generate SNMP device data files"
# ─────────────────────────────────────────────────────────────────────────────

cat > "${INSTALL_DIR}/generate_devices.py" << PYEOF
#!/usr/bin/env python3
"""
Generate 10 Cisco .snmprec files for snmpsim lab.
Each device gets a port-NNNNN/public.snmprec file.
Counters use the snmpsim numeric variation module for live incrementing.
"""
import os, random

BASE_OUTPUT_DIR = "${INSTALL_DIR}/data"

DEVICES = [
    ("core-sw-01",   "Cisco IOS Software, Catalyst 6500 Software (s72033_rp-ADVENTERPRISEK9_WAN-M), Version 15.1(2)SY14", "1.3.6.1.4.1.9.1.282",  10000),
    ("core-sw-02",   "Cisco IOS Software, Catalyst 6500 Software (s72033_rp-ADVENTERPRISEK9_WAN-M), Version 15.1(2)SY14", "1.3.6.1.4.1.9.1.282",  10001),
    ("dist-sw-01",   "Cisco IOS Software, Catalyst 4500 Software (cat4500e-UNIVERSALK9-M), Version 15.2(4)E10",            "1.3.6.1.4.1.9.1.659",  10002),
    ("dist-sw-02",   "Cisco IOS Software, Catalyst 4500 Software (cat4500e-UNIVERSALK9-M), Version 15.2(4)E10",            "1.3.6.1.4.1.9.1.659",  10003),
    ("access-sw-01", "Cisco IOS Software, Catalyst 3750 Software (C3750E-UNIVERSALK9-M), Version 15.2(4)E9",               "1.3.6.1.4.1.9.1.516",  10004),
    ("access-sw-02", "Cisco IOS Software, Catalyst 3750 Software (C3750E-UNIVERSALK9-M), Version 15.2(4)E9",               "1.3.6.1.4.1.9.1.516",  10005),
    ("access-sw-03", "Cisco IOS Software, Catalyst 3750 Software (C3750E-UNIVERSALK9-M), Version 15.2(4)E9",               "1.3.6.1.4.1.9.1.516",  10006),
    ("rtr-01",       "Cisco IOS Software, Version 15.7(3)M8, RELEASE SOFTWARE (fc2) ISR 4321",                            "1.3.6.1.4.1.9.1.1861", 10007),
    ("rtr-02",       "Cisco IOS Software, Version 15.7(3)M8, RELEASE SOFTWARE (fc2) ISR 4321",                            "1.3.6.1.4.1.9.1.1861", 10008),
    ("fw-01",        "Cisco Adaptive Security Appliance Software Version 9.16(4)19",                                       "1.3.6.1.4.1.9.1.1902", 10009),
]

SWITCH_IFACES = [
    ("GigabitEthernet0/1",    1000000000),
    ("GigabitEthernet0/2",    1000000000),
    ("GigabitEthernet0/3",    1000000000),
    ("GigabitEthernet0/4",    1000000000),
    ("GigabitEthernet0/5",    1000000000),
    ("TenGigabitEthernet1/1", 10000000000),
    ("TenGigabitEthernet1/2", 10000000000),
]
ROUTER_IFACES = [
    ("GigabitEthernet0/0/0", 1000000000),
    ("GigabitEthernet0/0/1", 1000000000),
    ("Serial0/1/0",          1544000),
]
FW_IFACES = [
    ("GigabitEthernet0/0",  1000000000),
    ("GigabitEthernet0/1",  1000000000),
    ("GigabitEthernet0/2",  1000000000),
    ("Management0/0",       1000000000),
]

MAX32 = 4294967295

def rand_mac(seed):
    random.seed(seed)
    return "".join(f"{random.randint(0,255):02x}" for _ in range(6))

def counter(initial, offset, deviation=0):
    p = f"initial={initial},offset={offset},cumulative=1,min=0,max={MAX32},wrap=1"
    if deviation: p += f",deviation={deviation}"
    return ("65:numeric", p)

def gauge(initial, lo, hi, deviation):
    return ("66:numeric", f"initial={initial},min={lo},max={hi},deviation={deviation},rate=0")

def timeticks(initial):
    return ("67:numeric", f"initial={initial},offset=100,cumulative=1,min=0,max={MAX32}")

def ln(oid, tv):
    return f"{oid}|{tv[0]}|{tv[1]}"

def make_snmprec(idx, hostname, descr, sysoid, ifaces):
    random.seed(idx * 1000)
    uptime   = random.randint(500_000, 80_000_000)
    cpu_base = random.randint(5, 35)
    mem_used = random.randint(50_000_000, 200_000_000)
    mem_free = random.randint(20_000_000, 100_000_000)
    lines = []

    lines.append(f"1.3.6.1.2.1.1.1.0|4|{descr}")
    lines.append(f"1.3.6.1.2.1.1.2.0|6|{sysoid}")
    lines.append(ln("1.3.6.1.2.1.1.3.0", timeticks(uptime)))
    lines.append(f"1.3.6.1.2.1.1.4.0|4|noc@lab.local")
    lines.append(f"1.3.6.1.2.1.1.5.0|4|{hostname}.lab.local")
    lines.append(f"1.3.6.1.2.1.1.6.0|4|Lab - Rack A")
    lines.append(f"1.3.6.1.2.1.1.7.0|2|78")
    lines.append(f"1.3.6.1.2.1.2.1.0|2|{len(ifaces)}")

    for i, (ifdescr, ifspeed) in enumerate(ifaces, start=1):
        random.seed(idx * 200 + i)
        mac         = rand_mac(idx * 100 + i)
        oper        = 1 if i < len(ifaces) else 2
        in_oct      = random.randint(10_000_000, 999_000_000)
        out_oct     = random.randint(10_000_000, 999_000_000)
        in_pkt      = in_oct  // random.randint(64, 512)
        out_pkt     = out_oct // random.randint(64, 512)
        err         = random.randint(0, 50)
        disc        = random.randint(0, 30)
        if ifspeed >= 10_000_000_000:
            oo, od = random.randint(5_000_000, 20_000_000), random.randint(5_000, 20_000)
        elif ifspeed >= 1_000_000_000:
            oo, od = random.randint(500_000, 5_000_000),   random.randint(500, 5_000)
        else:
            oo, od = random.randint(10_000, 100_000),      random.randint(10, 100)

        lines += [
            f"1.3.6.1.2.1.2.2.1.1.{i}|2|{i}",
            f"1.3.6.1.2.1.2.2.1.2.{i}|4|{ifdescr}",
            f"1.3.6.1.2.1.2.2.1.3.{i}|2|6",
            f"1.3.6.1.2.1.2.2.1.4.{i}|2|1500",
            f"1.3.6.1.2.1.2.2.1.5.{i}|66|{ifspeed}",
            f"1.3.6.1.2.1.2.2.1.6.{i}|4x|{mac}",
            f"1.3.6.1.2.1.2.2.1.7.{i}|2|1",
            f"1.3.6.1.2.1.2.2.1.8.{i}|2|{oper}",
            ln(f"1.3.6.1.2.1.2.2.1.10.{i}", counter(in_oct,  oo, int(oo*0.1))),
            ln(f"1.3.6.1.2.1.2.2.1.11.{i}", counter(in_pkt,  od, int(od*0.1))),
            ln(f"1.3.6.1.2.1.2.2.1.13.{i}", counter(disc, 0, 1)),
            ln(f"1.3.6.1.2.1.2.2.1.14.{i}", counter(err,  0, 1)),
            ln(f"1.3.6.1.2.1.2.2.1.16.{i}", counter(out_oct, oo, int(oo*0.1))),
            ln(f"1.3.6.1.2.1.2.2.1.17.{i}", counter(out_pkt, od, int(od*0.1))),
            ln(f"1.3.6.1.2.1.2.2.1.19.{i}", counter(disc, 0, 1)),
            ln(f"1.3.6.1.2.1.2.2.1.20.{i}", counter(err,  0, 1)),
        ]

    cpu_lo = max(1, cpu_base - 10); cpu_hi = min(99, cpu_base + 20)
    cpu_dev = max(3, cpu_base // 3)
    lines += [
        f"1.3.6.1.4.1.9.9.109.1.1.1.1.2.1|2|1",
        ln("1.3.6.1.4.1.9.9.109.1.1.1.1.3.1", gauge(cpu_base, cpu_lo, cpu_hi, cpu_dev)),
        ln("1.3.6.1.4.1.9.9.109.1.1.1.1.4.1", gauge(cpu_base, cpu_lo, cpu_hi, cpu_dev)),
        ln("1.3.6.1.4.1.9.9.109.1.1.1.1.5.1", gauge(cpu_base, cpu_lo, cpu_hi, cpu_dev)),
        ln("1.3.6.1.4.1.9.2.1.57.0",           gauge(cpu_base, cpu_lo, cpu_hi, cpu_dev)),
        ln("1.3.6.1.4.1.9.2.1.58.0",           gauge(cpu_base, cpu_lo, cpu_hi, cpu_dev)),
        f"1.3.6.1.4.1.9.9.48.1.1.1.2.1|4|Processor",
        ln("1.3.6.1.4.1.9.9.48.1.1.1.5.1", gauge(mem_free, mem_free-5_000_000, mem_free+5_000_000, 2_000_000)),
        ln("1.3.6.1.4.1.9.9.48.1.1.1.6.1", gauge(mem_used, mem_used-5_000_000, mem_used+5_000_000, 2_000_000)),
        f"1.3.6.1.4.1.9.9.48.1.1.1.2.2|4|I/O",
        ln("1.3.6.1.4.1.9.9.48.1.1.1.5.2", gauge(mem_free//4, mem_free//4-1_000_000, mem_free//4+1_000_000, 500_000)),
        ln("1.3.6.1.4.1.9.9.48.1.1.1.6.2", gauge(mem_used//8, mem_used//8-500_000,   mem_used//8+500_000,   250_000)),
    ]
    return "\n".join(lines) + "\n"

for idx, (hostname, descr, sysoid, port) in enumerate(DEVICES):
    ifaces = ROUTER_IFACES if "rtr" in hostname else (FW_IFACES if "fw" in hostname else SWITCH_IFACES)
    content = make_snmprec(idx, hostname, descr, sysoid, ifaces)
    out_dir = os.path.join(BASE_OUTPUT_DIR, f"port-{port}")
    os.makedirs(out_dir, exist_ok=True)
    with open(os.path.join(out_dir, "public.snmprec"), "w") as f:
        f.write(content)
    print(f"  port-{port}/public.snmprec  ({hostname}, {len(ifaces)} interfaces)")

print("Done.")
PYEOF

info "Generating device data files..."
python3 "${INSTALL_DIR}/generate_devices.py"
chown -R "${SNMPSIM_USER}:${SNMPSIM_USER}" "${INSTALL_DIR}/data"
ok "Device data files generated"

# ─────────────────────────────────────────────────────────────────────────────
section "Step 5: Create start / stop scripts"
# ─────────────────────────────────────────────────────────────────────────────

cat > "${INSTALL_DIR}/start-sim.sh" << EOF
#!/bin/bash
# =============================================================================
# Start 10 Cisco SNMP agents — all SNMPv2c, community: public
# =============================================================================

SNMPSIM_BIN="${SNMPSIM_BIN}"
BASE_DATA_DIR="${INSTALL_DIR}/data"
LOGFILE="${INSTALL_DIR}/logs/snmpsim.log"
PID_DIR="/var/run/snmpsim.commands.responder"
VM_IP="${VM_IP}"

declare -A DEVICES=(
  [10000]="core-sw-01"
  [10001]="core-sw-02"
  [10002]="dist-sw-01"
  [10003]="dist-sw-02"
  [10004]="access-sw-01"
  [10005]="access-sw-02"
  [10006]="access-sw-03"
  [10007]="rtr-01"
  [10008]="rtr-02"
  [10009]="fw-01"
)

echo "Starting 10 Cisco SNMP agents on \${VM_IP} (SNMPv2c, community: public)..."
> "\${LOGFILE}"

for PORT in \$(echo "\${!DEVICES[@]}" | tr ' ' '\n' | sort -n); do
  NAME="\${DEVICES[\$PORT]}"
  \${SNMPSIM_BIN} \\
    --agent-udpv4-endpoint=\${VM_IP}:\${PORT} \\
    --data-dir="\${BASE_DATA_DIR}/port-\${PORT}" \\
    --process-user=${SNMPSIM_USER} \\
    --process-group=${SNMPSIM_USER} \\
    --pid-file="\${PID_DIR}/\${PORT}.pid" \\
    --daemonize \\
    --logging-method=file:\${LOGFILE}
  echo "  Started: \${NAME} on \${VM_IP}:\${PORT}"
done

echo ""
echo "Done. 10 agents running (SNMPv2c, community: public)"
echo "Verify: snmpwalk -v2c -c public \${VM_IP}:10000 1.3.6.1.2.1.1"
EOF

cat > "${INSTALL_DIR}/stop-sim.sh" << 'EOF'
#!/bin/bash
PID_DIR="/var/run/snmpsim.commands.responder"
echo "Stopping snmpsim agents..."
STOPPED=0
for pidfile in "${PID_DIR}"/*.pid; do
  [[ -f "$pidfile" ]] || continue
  PID=$(cat "$pidfile" 2>/dev/null)
  PORT=$(basename "$pidfile" .pid)
  if kill "$PID" 2>/dev/null; then
    echo "  Stopped port $PORT (PID $PID)"
    STOPPED=$((STOPPED+1))
  fi
  rm -f "$pidfile"
done
if [[ $STOPPED -eq 0 ]]; then
  pkill -f snmpsim-command-responder 2>/dev/null && echo "  Stopped via pkill" || echo "  No snmpsim process found."
fi
echo "Done."
EOF

cat > "${INSTALL_DIR}/restart-sim.sh" << 'EOF'
#!/bin/bash
cd "$(dirname "$0")"
./stop-sim.sh
sleep 2
rm -rf /tmp/snmpsim/*
./start-sim.sh
EOF

chmod +x "${INSTALL_DIR}"/{start-sim.sh,stop-sim.sh,restart-sim.sh}
ok "start-sim.sh, stop-sim.sh, restart-sim.sh created"

# ─────────────────────────────────────────────────────────────────────────────
section "Step 6: Create trap generator"
# ─────────────────────────────────────────────────────────────────────────────

cat > "${INSTALL_DIR}/trap-generator.sh" << EOF
#!/bin/bash
# =============================================================================
# trap-generator.sh
# Sends one random SNMP trap to the configured destination.
# Run manually or via cron.
#
# Usage:  ./trap-generator.sh [--host <IP>] [--port <PORT>]
#         Defaults to compiled-in values if no args given.
# =============================================================================

SEVONE_IP="\${1:-${TRAP_HOST}}"
SEVONE_PORT="\${2:-${TRAP_PORT}}"
COMMUNITY="public"

declare -A DEVICES
DEVICES["core-sw-01"]="${VM_IP}:10000:1.3.6.1.4.1.9.1.282"
DEVICES["core-sw-02"]="${VM_IP}:10001:1.3.6.1.4.1.9.1.282"
DEVICES["dist-sw-01"]="${VM_IP}:10002:1.3.6.1.4.1.9.1.659"
DEVICES["dist-sw-02"]="${VM_IP}:10003:1.3.6.1.4.1.9.1.659"
DEVICES["access-sw-01"]="${VM_IP}:10004:1.3.6.1.4.1.9.1.516"
DEVICES["access-sw-02"]="${VM_IP}:10005:1.3.6.1.4.1.9.1.516"
DEVICES["access-sw-03"]="${VM_IP}:10006:1.3.6.1.4.1.9.1.516"
DEVICES["rtr-01"]="${VM_IP}:10007:1.3.6.1.4.1.9.1.1861"
DEVICES["rtr-02"]="${VM_IP}:10008:1.3.6.1.4.1.9.1.1861"
DEVICES["fw-01"]="${VM_IP}:10009:1.3.6.1.4.1.9.1.1902"

SWITCH_IFACES=("GigabitEthernet0/1" "GigabitEthernet0/2" "GigabitEthernet0/3" "GigabitEthernet0/4" "GigabitEthernet0/5" "TenGigabitEthernet1/1" "TenGigabitEthernet1/2")
ROUTER_IFACES=("GigabitEthernet0/0/0" "GigabitEthernet0/0/1" "Serial0/1/0")
FW_IFACES=("GigabitEthernet0/0" "GigabitEthernet0/1" "GigabitEthernet0/2" "Management0/0")

random_element() { local a=("\$@"); echo "\${a[\$RANDOM % \${#a[@]}]}"; }
random_device()  { local k=("\${!DEVICES[@]}"); echo "\${k[\$RANDOM % \${#k[@]}]}"; }

get_ifaces() {
  case "\$1" in
    rtr*) echo "\${ROUTER_IFACES[@]}" ;;
    fw*)  echo "\${FW_IFACES[@]}" ;;
    *)    echo "\${SWITCH_IFACES[@]}" ;;
  esac
}

send_linkDown() {
  local dev="\$1"; local ifaces=(\$(get_ifaces "\$dev"))
  local iface=\$(random_element "\${ifaces[@]}"); local idx=\$((RANDOM % \${#ifaces[@]} + 1))
  echo "[\$(date '+%H:%M:%S')] linkDown          | \$dev | \$iface"
  snmptrap -v2c -c "\$COMMUNITY" "\$SEVONE_IP:\$SEVONE_PORT" "" 1.3.6.1.6.3.1.1.5.3 \\
    1.3.6.1.2.1.2.2.1.1.\$idx i \$idx 1.3.6.1.2.1.2.2.1.2.\$idx s "\$iface" \\
    1.3.6.1.2.1.2.2.1.7.\$idx i 2 1.3.6.1.2.1.2.2.1.8.\$idx i 2
}

send_linkUp() {
  local dev="\$1"; local ifaces=(\$(get_ifaces "\$dev"))
  local iface=\$(random_element "\${ifaces[@]}"); local idx=\$((RANDOM % \${#ifaces[@]} + 1))
  echo "[\$(date '+%H:%M:%S')] linkUp            | \$dev | \$iface"
  snmptrap -v2c -c "\$COMMUNITY" "\$SEVONE_IP:\$SEVONE_PORT" "" 1.3.6.1.6.3.1.1.5.4 \\
    1.3.6.1.2.1.2.2.1.1.\$idx i \$idx 1.3.6.1.2.1.2.2.1.2.\$idx s "\$iface" \\
    1.3.6.1.2.1.2.2.1.7.\$idx i 1 1.3.6.1.2.1.2.2.1.8.\$idx i 1
}

send_coldStart() {
  echo "[\$(date '+%H:%M:%S')] coldStart         | \$1"
  snmptrap -v2c -c "\$COMMUNITY" "\$SEVONE_IP:\$SEVONE_PORT" "" 1.3.6.1.6.3.1.1.5.1
}

send_warmStart() {
  echo "[\$(date '+%H:%M:%S')] warmStart         | \$1"
  snmptrap -v2c -c "\$COMMUNITY" "\$SEVONE_IP:\$SEVONE_PORT" "" 1.3.6.1.6.3.1.1.5.2
}

send_ospfNbrStateChange() {
  [[ "\$1" != rtr* ]] && return
  local peer="10.\$((RANDOM%255)).\$((RANDOM%255)).\$((RANDOM%255))"
  local state=\$((RANDOM%8+1))
  echo "[\$(date '+%H:%M:%S')] ospfNbrStateChange| \$1 | peer \$peer state \$state"
  snmptrap -v2c -c "\$COMMUNITY" "\$SEVONE_IP:\$SEVONE_PORT" "" 1.3.6.1.4.1.9.10.99.0.1 \\
    1.3.6.1.2.1.14.10.1.1.\$peer a "\$peer" 1.3.6.1.2.1.14.10.1.6.\$peer i \$state \\
    1.3.6.1.2.1.14.4.1.2.0 s "0.0.0.0"
}

send_bgpEstablished() {
  [[ "\$1" != rtr* ]] && return
  local peer="192.168.\$((RANDOM%255)).\$((RANDOM%255))"
  local as=\$((RANDOM%65000+1000))
  echo "[\$(date '+%H:%M:%S')] bgpEstablished    | \$1 | peer \$peer AS\$as"
  snmptrap -v2c -c "\$COMMUNITY" "\$SEVONE_IP:\$SEVONE_PORT" "" 1.3.6.1.2.1.15.7.1 \\
    1.3.6.1.2.1.15.3.1.7.\$peer i 6 1.3.6.1.2.1.15.3.1.9.\$peer i \$as
}

send_bgpBackwardTransition() {
  [[ "\$1" != rtr* ]] && return
  local peer="192.168.\$((RANDOM%255)).\$((RANDOM%255))"
  local as=\$((RANDOM%65000+1000)); local state=\$((RANDOM%5+1))
  echo "[\$(date '+%H:%M:%S')] bgpBackward       | \$1 | peer \$peer state \$state"
  snmptrap -v2c -c "\$COMMUNITY" "\$SEVONE_IP:\$SEVONE_PORT" "" 1.3.6.1.2.1.15.7.2 \\
    1.3.6.1.2.1.15.3.1.7.\$peer i \$state 1.3.6.1.2.1.15.3.1.9.\$peer i \$as
}

send_cpuThreshold() {
  local cpu=\$((RANDOM%40+60))
  echo "[\$(date '+%H:%M:%S')] cpuThreshold      | \$1 | CPU \${cpu}%"
  snmptrap -v2c -c "\$COMMUNITY" "\$SEVONE_IP:\$SEVONE_PORT" "" 1.3.6.1.4.1.9.9.109.0.1 \\
    1.3.6.1.4.1.9.9.109.1.1.1.1.3.1 i \$cpu \\
    1.3.6.1.4.1.9.9.109.1.1.1.1.4.1 i \$((cpu-RANDOM%10)) \\
    1.3.6.1.4.1.9.9.109.1.1.1.1.5.1 i \$((cpu-RANDOM%15))
}

TRAP_TYPES=(linkDown linkDown linkDown linkUp linkUp linkUp coldStart warmStart
            ospfNbrStateChange ospfNbrStateChange bgpEstablished
            bgpBackwardTransition cpuThreshold)

trap_type=\$(random_element "\${TRAP_TYPES[@]}")
device=\$(random_device)

echo "--- \$(date '+%Y-%m-%d %H:%M:%S') | \$trap_type from \$device -> \$SEVONE_IP:\$SEVONE_PORT ---"
case "\$trap_type" in
  linkDown)              send_linkDown "\$device" ;;
  linkUp)                send_linkUp "\$device" ;;
  coldStart)             send_coldStart "\$device" ;;
  warmStart)             send_warmStart "\$device" ;;
  ospfNbrStateChange)    send_ospfNbrStateChange "\$device" ;;
  bgpEstablished)        send_bgpEstablished "\$device" ;;
  bgpBackwardTransition) send_bgpBackwardTransition "\$device" ;;
  cpuThreshold)          send_cpuThreshold "\$device" ;;
esac
EOF

chmod +x "${INSTALL_DIR}/trap-generator.sh"
ok "trap-generator.sh created"

# ─────────────────────────────────────────────────────────────────────────────
section "Step 7: Build and install nflow-generator"
# ─────────────────────────────────────────────────────────────────────────────

NFLOW_BIN="${INSTALL_DIR}/nflow-generator"

if [[ -f "$NFLOW_BIN" ]]; then
  ok "nflow-generator already present — skipping build"
else
  info "Cloning and building nflow-generator..."
  TMPDIR=$(mktemp -d)
  git clone --quiet https://github.com/nerdalert/nflow-generator.git "$TMPDIR/nflow-generator"
  cd "$TMPDIR/nflow-generator"
  go build -o "$NFLOW_BIN" .
  cd /
  rm -rf "$TMPDIR"
  ok "nflow-generator built: $NFLOW_BIN"
fi

# ─────────────────────────────────────────────────────────────────────────────
section "Step 8: Create systemd services"
# ─────────────────────────────────────────────────────────────────────────────

# NetFlow systemd service
cat > /etc/systemd/system/snmpsim-netflow.service << EOF
[Unit]
Description=SevOne Lab NetFlow Generator
After=network.target

[Service]
ExecStart=${INSTALL_DIR}/nflow-generator -t ${NETFLOW_HOST} -p ${NETFLOW_PORT}
Restart=always
RestartSec=5
StandardOutput=journal
StandardError=journal

[Install]
WantedBy=multi-user.target
EOF

# Trap generator systemd timer (every 5 minutes)
cat > /etc/systemd/system/snmpsim-traps.service << EOF
[Unit]
Description=SevOne Lab Trap Generator (single run)

[Service]
Type=oneshot
ExecStart=${INSTALL_DIR}/trap-generator.sh ${TRAP_HOST} ${TRAP_PORT}
StandardOutput=journal
StandardError=journal
EOF

cat > /etc/systemd/system/snmpsim-traps.timer << EOF
[Unit]
Description=SevOne Lab Trap Generator — every 5 minutes

[Timer]
OnBootSec=60
OnUnitActiveSec=5min
Unit=snmpsim-traps.service

[Install]
WantedBy=timers.target
EOF

# SNMP simulator systemd service
# Type=oneshot + RemainAfterExit=yes is correct for a script that launches
# background daemons and exits. HOME must be set so snmpsim can find its
# variation modules path (~/.snmpsim/variation).
cat > /etc/systemd/system/snmpsim-agents.service << EOF
[Unit]
Description=SevOne Lab SNMP Simulator (10 Cisco agents)
After=network.target

[Service]
Type=oneshot
RemainAfterExit=yes
Environment=HOME=/root
ExecStart=${INSTALL_DIR}/start-sim.sh
ExecStop=${INSTALL_DIR}/stop-sim.sh
ExecReload=${INSTALL_DIR}/restart-sim.sh

[Install]
WantedBy=multi-user.target
EOF

systemctl daemon-reload
systemctl enable --now snmpsim-agents.service
systemctl enable --now snmpsim-netflow.service
systemctl enable --now snmpsim-traps.timer

ok "systemd services created, enabled, and started:"
ok "  snmpsim-agents.service   (SNMP    -> ${VM_IP}:10000-10009, community: public)"
ok "  snmpsim-netflow.service  (NetFlow -> ${NETFLOW_HOST}:${NETFLOW_PORT})"
ok "  snmpsim-traps.timer      (Traps   -> ${TRAP_HOST}:${TRAP_PORT} every 5 min)"

# ─────────────────────────────────────────────────────────────────────────────
section "Step 9: Fix ownership"
# ─────────────────────────────────────────────────────────────────────────────

chown -R "${SNMPSIM_USER}:${SNMPSIM_USER}" "${INSTALL_DIR}"
chown root:root "${INSTALL_DIR}/start-sim.sh" "${INSTALL_DIR}/stop-sim.sh" "${INSTALL_DIR}/restart-sim.sh"
chmod +x "${INSTALL_DIR}/start-sim.sh" "${INSTALL_DIR}/stop-sim.sh" "${INSTALL_DIR}/restart-sim.sh"

# ─────────────────────────────────────────────────────────────────────────────
section "Step 10: Verify installation"
# ─────────────────────────────────────────────────────────────────────────────

sleep 3
PASS=0; FAIL=0

check() {
  local desc="$1"; local cmd="$2"
  if eval "$cmd" &>/dev/null; then
    ok "$desc"
    PASS=$((PASS+1))
  else
    error "$desc"
    FAIL=$((FAIL+1))
  fi
}

check "snmpsim-agents service active"   "systemctl is-active --quiet snmpsim-agents"
check "Port 10000 bound (core-sw-01)"   "ss -ulnp | grep -q ':10000'"
check "Port 10007 bound (rtr-01)"       "ss -ulnp | grep -q ':10007'"
check "SNMPv2c response (port 10000)"   "snmpget -v2c -c public ${VM_IP}:10000 1.3.6.1.2.1.1.5.0 2>/dev/null"
check "SNMPv2c response (port 10005)"   "snmpget -v2c -c public ${VM_IP}:10005 1.3.6.1.2.1.1.5.0 2>/dev/null"
check "SNMPv2c response (port 10009)"   "snmpget -v2c -c public ${VM_IP}:10009 1.3.6.1.2.1.1.5.0 2>/dev/null"
check "nflow-generator service active"  "systemctl is-active --quiet snmpsim-netflow"
check "trap timer active"               "systemctl is-active --quiet snmpsim-traps.timer"

echo ""
echo -e "${BLUE}═══════════════════════════════════════════════════════${NC}"
echo -e "  Checks passed: ${GREEN}${PASS}${NC}   Checks failed: ${RED}${FAIL}${NC}"
echo -e "${BLUE}═══════════════════════════════════════════════════════${NC}"

# ─────────────────────────────────────────────────────────────────────────────
# Final summary
# ─────────────────────────────────────────────────────────────────────────────
echo ""
echo -e "${BLUE}╔══════════════════════════════════════════════════════════╗${NC}"
echo -e "${BLUE}║  Installation complete                                   ║${NC}"
echo -e "${BLUE}╚══════════════════════════════════════════════════════════╝${NC}"
echo ""
echo -e "  Install directory : ${CYAN}${INSTALL_DIR}${NC}"
echo -e "  VM IP             : ${CYAN}${VM_IP}${NC}"
echo -e "  Trap destination  : ${CYAN}${TRAP_HOST}:${TRAP_PORT}${NC}"
echo -e "  NetFlow dest      : ${CYAN}${NETFLOW_HOST}:${NETFLOW_PORT}${NC}"
echo ""
  echo -e "  SNMP devices      : ${CYAN}${VM_IP}:10000 - ${VM_IP}:10009${NC}"
  echo -e "  SNMP version      : ${CYAN}v2c${NC}"
  echo -e "  Community string  : ${CYAN}public${NC}"
echo ""
echo -e "  ${YELLOW}Add each device to SevOne:${NC}"
echo -e "    IP: ${VM_IP}, SNMP Version: v2c, Community: public, Port: 10000 through 10009"
echo ""
echo -e "  ${YELLOW}Useful commands:${NC}"
echo -e "    ${INSTALL_DIR}/start-sim.sh"
echo -e "    ${INSTALL_DIR}/stop-sim.sh"
echo -e "    ${INSTALL_DIR}/restart-sim.sh"
echo -e "    ${INSTALL_DIR}/trap-generator.sh       # send one trap now"
echo -e "    systemctl status snmpsim-netflow"
echo -e "    systemctl status snmpsim-traps.timer"
echo -e "    tail -f ${INSTALL_DIR}/logs/snmpsim.log"
echo ""