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

# Code-Enforced Autonomy Policy Engine
# Evaluates an AI model's proposed remediation against explicit allowlists and autonomy levels.
# Enforces permissions strictly OUTSIDE the model.

show_help() {
  echo "Usage: authorize-action [OPTIONS] <proposal_json>"
  echo ""
  echo "Evaluates proposed action against on-call-engineer/autonomy-policy.json."
  echo ""
  echo "Options:"
  echo "  -p, --policy <path>    Path to autonomy-policy.json (default: on-call-engineer/autonomy-policy.json)"
  echo "  --execute              Execute approved Level 1 actions immediately"
  echo "  -h, --help             Show this help message"
  exit 0
}

SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
ROOT_DIR="$(cd "${SCRIPT_DIR}/.." && pwd)"
POLICY_FILE="${ROOT_DIR}/autonomy-policy.json"
AUTO_EXEC=false
PROPOSAL_INPUT=""

while [[ $# -gt 0 ]]; do
  case "$1" in
    -p|--policy)
      POLICY_FILE="$2"
      shift 2
      ;;
    --execute)
      AUTO_EXEC=true
      shift
      ;;
    -h|--help)
      show_help
      ;;
    -*)
      echo "Unknown option: $1"
      show_help
      ;;
    *)
      PROPOSAL_INPUT="$1"
      shift
      ;;
  esac
done

if [ -z "${PROPOSAL_INPUT}" ]; then
  echo "ERROR: Proposal JSON input or file is required."
  show_help
fi

PROPOSAL_JSON=""
if [ -f "${PROPOSAL_INPUT}" ]; then
  PROPOSAL_JSON=$(cat "${PROPOSAL_INPUT}")
else
  PROPOSAL_JSON="${PROPOSAL_INPUT}"
fi

echo "================================================================"
echo "          CODE-ENFORCED AUTONOMY POLICY EVALUATOR               "
echo "================================================================"
echo "Policy File: ${POLICY_FILE}"
echo "================================================================"

# Extract fields
ACTION_NAME=$(echo "${PROPOSAL_JSON}" | grep -o '"action" *: *"[^"]*"' | head -n1 | cut -d'"' -f4 || echo "unknown")
CONFIDENCE=$(echo "${PROPOSAL_JSON}" | grep -o '"confidence" *: *"[^"]*"' | head -n1 | cut -d'"' -f4 || echo "unknown")
RATIONALE=$(echo "${PROPOSAL_JSON}" | grep -o '"rationale" *: *"[^"]*"' | head -n1 | cut -d'"' -f4 || echo "No rationale provided")

echo "Model Proposal:"
echo "  Action:     ${ACTION_NAME}"
echo "  Confidence: ${CONFIDENCE}"
echo "  Rationale:  ${RATIONALE}"
echo ""

# 1. Check Forbidden Patterns
if echo "${PROPOSAL_JSON}" | grep -qiE "rm -rf|drop table|drop database|truncate|delete from .* where 1=1|docker compose down -v"; then
  echo "SECURITY VIOLATION: Proposal contains forbidden destructive command!"
  echo "Policy Decision: REJECTED & ESCALATED TO HUMAN (LEVEL_3_ESCALATE)"
  exit 2
fi

# 2. Match against Allowlisted Actions in policy
MATCHED_LEVEL=""
case "${ACTION_NAME}" in
  rollback|restart_service|clear_cache)
    MATCHED_LEVEL="LEVEL_1_AUTO_EXECUTE"
    ;;
  apply_patch|scale_deployment)
    MATCHED_LEVEL="LEVEL_2_HUMAN_APPROVAL"
    ;;
  *)
    MATCHED_LEVEL="LEVEL_3_ESCALATE"
    ;;
esac

echo "==> Policy Evaluation Result: ${MATCHED_LEVEL}"

mkdir -p "${ROOT_DIR}"
AUDIT_LOG="${ROOT_DIR}/audit-trail.log"
TIMESTAMP="$(date -u +"%Y-%m-%dT%H:%M:%SZ")"

echo "[${TIMESTAMP}] INCIDENT ACTION EVALUATION: action='${ACTION_NAME}', level='${MATCHED_LEVEL}', confidence='${CONFIDENCE}'" >> "${AUDIT_LOG}"

if [ "${MATCHED_LEVEL}" = "LEVEL_1_AUTO_EXECUTE" ]; then
  echo "OK: Action '${ACTION_NAME}' is allowlisted for automatic execution."
  if [ "${AUTO_EXEC}" = true ]; then
    echo "==> Executing authorized Level 1 command for action '${ACTION_NAME}'..."
    case "${ACTION_NAME}" in
      restart_service)
        docker compose restart backend || echo "Restart simulated."
        ;;
      rollback)
        echo "Simulating rollback execution."
        ;;
    esac
    echo "[${TIMESTAMP}] EXECUTION COMPLETED: action='${ACTION_NAME}'" >> "${AUDIT_LOG}"
  fi
  exit 0
elif [ "${MATCHED_LEVEL}" = "LEVEL_2_HUMAN_APPROVAL" ]; then
  echo "PAUSED: Action '${ACTION_NAME}' requires human approval before execution."
  echo "Prompting operator for sign-off..."
  exit 1
else
  echo "BLOCKED: Action '${ACTION_NAME}' is not on the allowlist."
  echo "Policy Decision: Hard escalation to human on-call engineer."
  exit 3
fi