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

# CASAN — Incident response (C7 / V23).
#
# Turns a detected security/ops event into a graded incident: classify severity,
# record a tamper-visible incident entry, and for HIGH/CRIT auto-engage the
# scoped kill-switch + fire an alert (reuses alert-dispatch.sh from H6 if present).
# Answers "when a gate catches an attack/spike/tamper — who is paged and what
# stops?" — severity, owner, kill-switch, runbook.
#
# Usage:
#   incident.sh raise <event-type> [detail] [--scope <s>] [--id <id>]
#   incident.sh status
# Exit: 0 recorded (LOW/MED) · 2 kill-switch engaged (HIGH/CRIT) · 64 usage.

SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
source "$SCRIPT_DIR/casan-paths.sh"
PROJECT_ROOT="$CASAN_APP_ROOT"
SEC_DIR="$CASAN_HARNESS_ROOT/security"
LOG="$CASAN_STATE_ROOT/logs/level5/incidents.jsonl"
RUNBOOK="$SEC_DIR/incident-runbook.md"
SEVMAP="$SEC_DIR/incident-severity.map"
mkdir -p "$(dirname "$LOG")"
# shellcheck source=casan-log.sh
source "$SCRIPT_DIR/casan-log.sh"

CMD="${1:-}"
ts() { date -u +"%Y-%m-%dT%H:%M:%SZ"; }

# owner routing by severity (production: on-call rota / IdP group).
owner_for() { case "$1" in CRIT) echo "security-oncall" ;; HIGH) echo "ops-oncall" ;; MED) echo "tech-lead" ;; *) echo "triage" ;; esac; }

if [[ "$CMD" == "status" ]]; then
  n=$(grep -c . "$LOG" 2>/dev/null || echo 0)
  echo "INCIDENTS total=$n log=$LOG"
  [[ -f "$LOG" ]] && tail -5 "$LOG"
  exit 0
fi
[[ "$CMD" == "raise" ]] || { echo "Usage: incident.sh raise <event-type> [detail] [--scope <s>] [--id <id>]" >&2; exit 64; }

EVENT="${2:-}"; DETAIL="${3:-}"
[[ -n "$EVENT" ]] || { echo "usage: incident.sh raise <event-type> [detail]" >&2; exit 64; }
SCOPE="project"; ID="${CASAN_PROJECT:-current}"
shift 2 2>/dev/null || true
while [[ "$#" -gt 0 ]]; do
  case "$1" in
    --scope) SCOPE="${2:-project}"; shift 2 ;;
    --id) ID="${2:-current}"; shift 2 ;;
    *) shift ;;
  esac
done

# Classify severity from the map (fallback to default).
SEV="$(awk -v e="$EVENT" '$1==e {print $2; exit}' "$SEVMAP" 2>/dev/null)"
[[ -n "$SEV" ]] || SEV="$(awk '$1=="default" {print $2; exit}' "$SEVMAP" 2>/dev/null)"
[[ -n "$SEV" ]] || SEV="MED"
OWNER="$(owner_for "$SEV")"
TS="$(ts)"
ACTION="recorded"

# HIGH/CRIT → engage the scoped kill-switch (stop the blast radius).
if [[ "$SEV" == "CRIT" || "$SEV" == "HIGH" ]]; then
  bash "$SCRIPT_DIR/kill-switch.sh" engage "$SCOPE" "$ID" "incident:$EVENT" >/dev/null 2>&1 || true
  ACTION="kill_switch_engaged"
  # Fire an alert through the H6 dispatcher if it is wired up.
  if [[ -x "$SCRIPT_DIR/alert-dispatch.sh" ]]; then
    bash "$SCRIPT_DIR/alert-dispatch.sh" "$SEV" "incident:$EVENT" "$DETAIL" >/dev/null 2>&1 || true
  fi
  casan_log error incident "INCIDENT sev=$SEV event=$EVENT scope=$SCOPE id=$ID → kill-switch ENGAGED owner=$OWNER"
else
  casan_log warn incident "INCIDENT sev=$SEV event=$EVENT scope=$SCOPE id=$ID owner=$OWNER"
fi

# SEC-05 (M-05): the keyless printf fallback below must not permit JSON injection
# either — strip quotes/backslashes/newlines from interpolated fields so a crafted
# EVENT/OWNER/SCOPE cannot forge a second incident record.
_json_strip() { local s="${1//\\/}"; s="${s//\"/}"; s="${s//$'\n'/ }"; s="${s//$'\r'/ }"; printf '%s' "$s"; }

# Record a structured incident entry.
python - "$LOG" "$TS" "$EVENT" "$SEV" "$OWNER" "$SCOPE" "$ID" "$ACTION" "$DETAIL" "$RUNBOOK" <<'PY' 2>/dev/null || \
  printf '{"timestamp":"%s","event":"%s","severity":"%s","owner":"%s","scope":"%s","id":"%s","action":"%s"}\n' \
    "$(_json_strip "$TS")" "$(_json_strip "$EVENT")" "$(_json_strip "$SEV")" "$(_json_strip "$OWNER")" "$(_json_strip "$SCOPE")" "$(_json_strip "$ID")" "$(_json_strip "$ACTION")" >> "$LOG"
import json, sys
log, ts, event, sev, owner, scope, iid, action, detail, runbook = sys.argv[1:11]
with open(log, "a", encoding="utf-8") as f:
    f.write(json.dumps({
        "timestamp": ts, "event": event, "severity": sev, "owner": owner,
        "scope": scope, "id": iid, "action": action, "detail": detail[:300],
        "runbook": runbook,
    }) + "\n")
PY

echo "INCIDENT_RAISED sev=$SEV event=$EVENT owner=$OWNER scope=$SCOPE id=$ID action=$ACTION runbook=$RUNBOOK"
[[ "$SEV" == "CRIT" || "$SEV" == "HIGH" ]] && exit 2 || exit 0