import { normalizeLowercaseStringOrEmpty } from "../shared/string-coerce.js";

const TOOL_CALL_NAME_MAX_CHARS = 64;
const TOOL_CALL_NAME_RE = /^[A-Za-z0-9_:.-]+$/;

export function normalizeAllowedToolNames(allowedToolNames?: Iterable<string>): Set<string> | null {
  if (!allowedToolNames) {
    return null;
  }
  const normalized = new Set<string>();
  for (const name of allowedToolNames) {
    if (typeof name !== "string") {
      continue;
    }
    const trimmed = name.trim();
    if (!trimmed) {
      continue;
    }
    normalized.add(normalizeLowercaseStringOrEmpty(trimmed));
  }
  return normalized.size > 0 ? normalized : null;
}

export function isAllowedToolCallName(
  name: unknown,
  allowedToolNames: Set<string> | null,
): boolean {
  if (typeof name !== "string") {
    return false;
  }
  const trimmed = name.trim();
  if (!trimmed) {
    return false;
  }
  if (trimmed.length > TOOL_CALL_NAME_MAX_CHARS || !TOOL_CALL_NAME_RE.test(trimmed)) {
    return false;
  }
  if (!allowedToolNames) {
    return true;
  }
  return allowedToolNames.has(normalizeLowercaseStringOrEmpty(trimmed));
}