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

# Usage:
#   scripts/send-wazuh-proposal-required-events.sh [selector] [count] [delay_seconds]
#
# selector:
#   all | a1 | a2 | a3 | a4 | <usecase_id>
#   example usecase_id: A2-01, A3-05, A4-24

SELECTOR="${1:-all}"
COUNT="${2:-1}"
DELAY="${3:-0.3}"
EVENT_DELAY="${EVENT_DELAY:-0.05}"
DRY_RUN="${DRY_RUN:-0}"
FOREVER="false"
PROFILE="${PROFILE:-simulation}"

for arg in "${@:4}"; do
  case "${arg}" in
    --forever)
      FOREVER="true"
      ;;
    --profile=*)
      PROFILE="${arg#*=}"
      ;;
    *)
      echo "error: unexpected argument '${arg}'"
      echo "usage: scripts/send-wazuh-proposal-required-events.sh [selector] [count] [delay_seconds] [--forever] [--profile=simulation|production]"
      exit 1
      ;;
  esac
done

WAZUH_SYSLOG_HOST="${WAZUH_SYSLOG_HOST:-127.0.0.1}"
WAZUH_SYSLOG_PORT="${WAZUH_SYSLOG_PORT:-514}"

FGT_DEVNAME="${FGT_DEVNAME:-FGT80F-Branch01}"
FGT_DEVID="${FGT_DEVID:-FGT80FTK20000001}"
WIN_HOST="${WIN_HOST:-win-dc01}"
DNS_HOST="${DNS_HOST:-dns-fw-01}"
SIM_VPN_USER="${SIM_VPN_USER:-remote.user}"

if ! [[ "${COUNT}" =~ ^[0-9]+$ ]] || [[ "${COUNT}" -lt 1 ]]; then
  echo "error: count must be a positive integer"
  exit 1
fi

if ! [[ "${DELAY}" =~ ^[0-9]+([.][0-9]+)?$ ]]; then
  echo "error: delay must be numeric"
  exit 1
fi

if ! [[ "${EVENT_DELAY}" =~ ^[0-9]+([.][0-9]+)?$ ]]; then
  echo "error: EVENT_DELAY must be numeric"
  exit 1
fi

if [[ "${PROFILE}" != "simulation" && "${PROFILE}" != "production" ]]; then
  echo "error: profile must be simulation or production"
  exit 1
fi

rand_public_ip() {
  if [[ $((RANDOM % 2)) -eq 0 ]]; then
    echo "198.51.100.$((RANDOM % 240 + 10))"
  else
    echo "203.0.113.$((RANDOM % 240 + 10))"
  fi
}

rand_private_ip() {
  echo "10.$((RANDOM % 20 + 10)).$((RANDOM % 200 + 1)).$((RANDOM % 240 + 10))"
}

rand_domain() {
  echo "ioc-$((RANDOM % 9000 + 1000)).malicious.example"
}

emit_syslog() {
  local msg="$1"
  local sent="false"

  if [[ "${DRY_RUN}" == "1" ]]; then
    echo "[DRY_RUN $(date -u +'%Y-%m-%dT%H:%M:%SZ')] ${msg}"
    return 0
  fi

  if command -v nc >/dev/null 2>&1; then
    if printf "%s\n" "${msg}" | nc -u -w1 "${WAZUH_SYSLOG_HOST}" "${WAZUH_SYSLOG_PORT}"; then
      sent="true"
    fi
  fi

  if [[ "${sent}" != "true" ]]; then
    if printf "%s\n" "${msg}" >"/dev/udp/${WAZUH_SYSLOG_HOST}/${WAZUH_SYSLOG_PORT}" 2>/dev/null; then
      sent="true"
    fi
  fi

  if [[ "${sent}" != "true" ]]; then
    echo "error: failed to send syslog event to ${WAZUH_SYSLOG_HOST}:${WAZUH_SYSLOG_PORT}/udp"
    return 1
  fi

  echo "[$(date -u +'%Y-%m-%dT%H:%M:%SZ')] sent: ${msg}"
}

selector_matches() {
  local id="$1"
  local section="$2"
  local sel
  sel="$(echo "${SELECTOR}" | tr '[:upper:]' '[:lower:]')"
  local idl
  idl="$(echo "${id}" | tr '[:upper:]' '[:lower:]')"
  local sec
  sec="$(echo "${section}" | tr '[:upper:]' '[:lower:]')"

  [[ "${sel}" == "all" || "${sel}" == "${sec}" || "${sel}" == "${idl}" ]]
}

emit_fgt_usecase() {
  local id="$1"
  local section="$2"
  local severity="$3"
  local usecase="$4"
  local body="$5"

  selector_matches "${id}" "${section}" || return 0

  local tags
  if [[ "${PROFILE}" == "production" ]]; then
    tags="soc_mvp_test=true source=fortigate severity=${severity}"
  else
    tags="soc_mvp_test=true source=fortigate section=${section} usecase_id=${id} severity=${severity} usecase=\"${usecase}\""
  fi
  emit_syslog "<190>date=$(date '+%Y-%m-%d') time=$(date '+%H:%M:%S') devname=\"${FGT_DEVNAME}\" devid=\"${FGT_DEVID}\" eventtime=$(date +%s) vd=\"root\" ${tags} ${body}"
  sleep "${EVENT_DELAY}"
}

emit_dns_usecase() {
  local id="$1"
  local section="$2"
  local severity="$3"
  local usecase="$4"
  local body="$5"

  selector_matches "${id}" "${section}" || return 0

  local tags
  if [[ "${PROFILE}" == "production" ]]; then
    tags="soc_mvp_test=true source=dns severity=${severity}"
  else
    tags="soc_mvp_test=true source=dns section=${section} usecase_id=${id} severity=${severity} usecase=\"${usecase}\""
  fi
  emit_syslog "<189>$(date '+%b %d %H:%M:%S') ${DNS_HOST} ${tags} ${body}"
  sleep "${EVENT_DELAY}"
}

emit_windows_usecase() {
  local id="$1"
  local section="$2"
  local severity="$3"
  local usecase="$4"
  local body="$5"

  selector_matches "${id}" "${section}" || return 0

  local tags
  if [[ "${PROFILE}" == "production" ]]; then
    tags="soc_mvp_test=true source=windows severity=${severity}"
  else
    tags="soc_mvp_test=true source=windows section=${section} usecase_id=${id} severity=${severity} usecase=\"${usecase}\""
  fi
  emit_syslog "<182>$(date '+%b %d %H:%M:%S') ${WIN_HOST} ${tags} ${body}"
  sleep "${EVENT_DELAY}"
}

emit_a1() {
  local sip
  local domain
  local mip
  sip="$(rand_private_ip)"
  domain="$(rand_domain)"
  mip="$(rand_public_ip)"

  emit_dns_usecase "A1-01" "A1" "medium" \
    "DNS Network Traffic Communicate to Malicious Domain" \
    "event_type=ioc_dns_traffic src_ip=${sip} query=${domain} resolved_ip=${mip} action=blocked"

  emit_dns_usecase "A1-02" "A1" "medium" \
    "DNS Network Traffic Malicious Domain IOCs Detection" \
    "event_type=ioc_domain_match src_ip=${sip} ioc_type=domain ioc_value=${domain} feed=threatintel_main confidence=high action=alert"
}

emit_a2() {
  local pub
  local sip
  pub="$(rand_public_ip)"
  sip="$(rand_private_ip)"

  emit_fgt_usecase "A2-01" "A2" "high" "IPS IDS Network Traffic Allowed RDP from Public IPs" \
    "logid=\"0000000013\" type=\"traffic\" subtype=\"forward\" srcip=${pub} dstip=${sip} dstport=3389 service=\"RDP\" action=\"accept\" policyid=44"

  emit_fgt_usecase "A2-02" "A2" "high" "IPS IDS Firewall Account Admin Password Change" \
    "logid=\"0100044547\" type=\"event\" subtype=\"system\" user=\"admin\" action=\"password-change\" target_account=\"admin\""

  emit_fgt_usecase "A2-03" "A2" "high" "IPS IDS Firewall Account Create Add Admin Account" \
    "logid=\"0100044548\" type=\"event\" subtype=\"system\" user=\"admin\" action=\"create-admin\" target_account=\"secops_admin\""

  emit_fgt_usecase "A2-04" "A2" "high" "IPS IDS Firewall Configure Disabled Email Notification" \
    "logid=\"0100044551\" type=\"event\" subtype=\"system\" action=\"config-change\" config_item=\"alertemail\" config_value=\"disable\""

  emit_fgt_usecase "A2-05" "A2" "low" "IPS IDS Firewall Configure Download Configure FW" \
    "logid=\"0100044552\" type=\"event\" subtype=\"system\" action=\"download-config\" user=\"admin\""

  emit_fgt_usecase "A2-06" "A2" "medium" "IPS IDS IDS Alert Multiple Critical High" \
    "logid=\"0720018432\" type=\"utm\" subtype=\"ips\" action=\"detected\" attack=\"Multiple.Critical.High.Signatures\" severity=\"high\" count=7"

  emit_fgt_usecase "A2-07" "A2" "low" "IPS IDS Network Traffic Port Scanning" \
    "logid=\"0720018433\" type=\"utm\" subtype=\"anomaly\" attack=\"TCP.Port.Scan\" srcip=${pub} dstip=${sip} action=\"detected\""

  emit_fgt_usecase "A2-08" "A2" "medium" "IPS IDS Network Traffic IOC Detection" \
    "logid=\"0720018434\" type=\"utm\" subtype=\"ips\" ioc_type=ip ioc_value=$(rand_public_ip) action=\"blocked\""

  emit_fgt_usecase "A2-09" "A2" "medium" "IPS IDS Network Traffic Port Scanning from Private IP" \
    "logid=\"0720018435\" type=\"utm\" subtype=\"anomaly\" attack=\"Internal.Port.Scan\" srcip=$(rand_private_ip) dstip=$(rand_private_ip) action=\"detected\""

  emit_fgt_usecase "A2-10" "A2" "medium" "IPS IDS Network Traffic Communicate to Malicious IP" \
    "logid=\"0000000013\" type=\"traffic\" subtype=\"forward\" srcip=$(rand_private_ip) dstip=$(rand_public_ip) threat_label=\"known-c2\" action=\"accept\""
}

emit_a3() {
  local out_th
  out_th="$(rand_public_ip)"

  emit_fgt_usecase "A3-01" "A3" "high" "VPN Authentication Success from Guest Account" \
    "logid=\"0101037131\" type=\"event\" subtype=\"vpn\" action=\"ssl-login-success\" user=\"guest\" srcip=${out_th} country=\"TH\""

  emit_fgt_usecase "A3-02" "A3" "high" "VPN Authentication Success from Multiple Country" \
    "logid=\"0101037132\" type=\"event\" subtype=\"vpn\" action=\"ssl-login-success\" user=\"${SIM_VPN_USER}\" srcip=${out_th} country=\"US\" previous_country=\"TH\""

  emit_fgt_usecase "A3-03" "A3" "high" "VPN Authentication Brute Force Success" \
    "logid=\"0101037133\" type=\"event\" subtype=\"vpn\" action=\"ssl-login-success\" user=\"${SIM_VPN_USER}\" srcip=${out_th} failed_attempts_before_success=18"

  emit_fgt_usecase "A3-04" "A3" "low" "VPN Authentication Multiple Fail Many Accounts from One Source" \
    "logid=\"0101037134\" type=\"event\" subtype=\"vpn\" action=\"ssl-login-fail\" srcip=${out_th} failed_accounts=12"

  emit_fgt_usecase "A3-05" "A3" "high" "VPN Authentication Success from Outside Thailand" \
    "logid=\"0101037135\" type=\"event\" subtype=\"vpn\" action=\"ssl-login-success\" user=\"${SIM_VPN_USER}\" srcip=${out_th} country=\"US\" expected_country=\"TH\""
}

emit_a4() {
  emit_windows_usecase "A4-01" "A4" "medium" "Windows Authentication Multiple Fail from Privileged Account" \
    "event_id=4625 account=\"administrator\" src_ip=$(rand_private_ip) fail_count=9"
  emit_windows_usecase "A4-02" "A4" "medium" "Windows Authentication Multiple Fail from Service Account" \
    "event_id=4625 account=\"svc_backup\" src_ip=$(rand_private_ip) fail_count=11"
  emit_windows_usecase "A4-03" "A4" "medium" "Windows AD Enumeration with Malicious Tools" \
    "event_id=4688 process=\"adfind.exe\" user=\"user1\" host=\"${WIN_HOST}\""
  emit_windows_usecase "A4-04" "A4" "medium" "Windows Authentication Fail from Public IPs" \
    "event_id=4625 account=\"user1\" src_ip=$(rand_public_ip) fail_count=4"
  emit_windows_usecase "A4-05" "A4" "medium" "Windows File Share Enumeration to Single Destination" \
    "event_id=5145 account=\"user1\" src_ip=$(rand_private_ip) share=\"\\\\\\\\fileserver\\\\finance\" object_count=87"
  emit_windows_usecase "A4-06" "A4" "high" "Windows Authentication Success from Public IPs" \
    "event_id=4624 account=\"user2\" src_ip=$(rand_public_ip) logon_type=10"
  emit_windows_usecase "A4-07" "A4" "high" "Windows Authentication Privileged Account Impersonation" \
    "event_id=4624 account=\"administrator\" impersonation=true source_account=\"user2\""
  emit_windows_usecase "A4-08" "A4" "high" "Windows Authentication Successful Pass the Hash RDP" \
    "event_id=4624 account=\"administrator\" logon_type=10 auth_package=\"NTLM\" pth_indicator=true"
  emit_windows_usecase "A4-09" "A4" "high" "Windows Authentication Success from Guest Account" \
    "event_id=4624 account=\"guest\" logon_type=3"
  emit_windows_usecase "A4-10" "A4" "high" "Windows Authentication Interactive Logon Success by Service Account" \
    "event_id=4624 account=\"svc_backup\" logon_type=2"
  emit_windows_usecase "A4-11" "A4" "high" "Windows Account Added to Privileged Custom Group" \
    "event_id=4732 account=\"user3\" target_group=\"SOC-Privileged-Custom\""
  emit_windows_usecase "A4-12" "A4" "high" "Windows Account Added to Privileged Group" \
    "event_id=4728 account=\"user3\" target_group=\"Domain Admins\""
  emit_windows_usecase "A4-13" "A4" "high" "Windows Domain Configure DSRM Password Reset" \
    "event_id=4794 account=\"administrator\" action=\"dsrm-password-reset\""
  emit_windows_usecase "A4-14" "A4" "low" "Windows Authentication Multiple Fail One Account from Many Sources" \
    "event_id=4625 account=\"user4\" src_count=15 fail_count=28"
  emit_windows_usecase "A4-15" "A4" "low" "Windows Authentication Multiple Fail Many Accounts from One Source" \
    "event_id=4625 src_ip=$(rand_private_ip) account_count=18 fail_count=42"
  emit_windows_usecase "A4-16" "A4" "low" "Windows Authentication Multiple Fail from Guest Account" \
    "event_id=4625 account=\"guest\" fail_count=9"
  emit_windows_usecase "A4-17" "A4" "low" "Windows Authentication Multiple Fail One Account from One Source" \
    "event_id=4625 account=\"user5\" src_ip=$(rand_private_ip) fail_count=10"
  emit_windows_usecase "A4-18" "A4" "low" "Windows Authentication Multiple Interactive Logon Denied" \
    "event_id=4625 account=\"user6\" logon_type=2 fail_count=7"
  emit_windows_usecase "A4-19" "A4" "low" "Windows Authentication Password Spray" \
    "event_id=4625 spray=true src_ip=$(rand_public_ip) attempted_accounts=25"
  emit_windows_usecase "A4-20" "A4" "low" "Windows Authentication Attempt from Disabled Account" \
    "event_id=4625 account=\"disabled.user\" status=\"0xC0000072\""
  emit_windows_usecase "A4-21" "A4" "low" "Windows Domain Account Created" \
    "event_id=4720 account=\"new.domain.user\" account_type=\"domain\""
  emit_windows_usecase "A4-22" "A4" "low" "Windows Local Account Re Enabled" \
    "event_id=4722 account=\"local.user\" account_type=\"local\""
  emit_windows_usecase "A4-23" "A4" "low" "Windows Local Account Created" \
    "event_id=4720 account=\"local.new\" account_type=\"local\""
  emit_windows_usecase "A4-24" "A4" "low" "Windows Domain Account Re Enabled" \
    "event_id=4722 account=\"domain.reenabled\" account_type=\"domain\""
}

emit_selected_set() {
  local sel
  sel="$(echo "${SELECTOR}" | tr '[:upper:]' '[:lower:]')"

  case "${sel}" in
    all)
      emit_a1
      emit_a2
      emit_a3
      emit_a4
      ;;
    a1|a1-*)
      emit_a1
      ;;
    a2|a2-*)
      emit_a2
      ;;
    a3|a3-*)
      emit_a3
      ;;
    a4|a4-*)
      emit_a4
      ;;
    *)
      # Exact usecase selectors (e.g. A3-05) are handled by selector_matches.
      emit_a1
      emit_a2
      emit_a3
      emit_a4
      ;;
  esac
}

echo "starting proposal-required log simulator"
echo "selector=${SELECTOR} count=${COUNT} delay=${DELAY}s event_delay=${EVENT_DELAY}s dry_run=${DRY_RUN} profile=${PROFILE}"
echo "target=${WAZUH_SYSLOG_HOST}:${WAZUH_SYSLOG_PORT}/udp"

if [[ "${FOREVER}" == "true" ]]; then
  echo "running forever with interval ${DELAY}s (Ctrl+C to stop)"
  trap 'echo; echo "stopped"; exit 0' INT TERM
  while true; do
    emit_selected_set
    sleep "${DELAY}"
  done
else
  for ((i=1; i<=COUNT; i++)); do
    emit_selected_set
    if [[ "${i}" -lt "${COUNT}" ]]; then
      sleep "${DELAY}"
    fi
  done
  echo "done"
fi