import {
  BUSINESS_DIRECTIVE_PREFIXES,
  firstNonEmptyLine,
  normalizeDirectiveText,
  resolveBusinessRoute
} from './business-routes.js';

/**
 * Business instruction prefixes that start an independent task.
 *
 * A message sent while another task is waiting for input is normally a
 * continuation. A unique registered directive anywhere in a structured block
 * is a new request and must get a new task/session instead of inheriting the
 * previous parser context. A field signature may select the parser mode for a
 * new task, but never changes continuation semantics by itself.
 */
function normalizedFirstLine(message: string): string {
  return normalizeDirectiveText(firstNonEmptyLine(message));
}

export function detectBusinessDirective(message: string): string | null {
  const line = normalizedFirstLine(message);
  if (!line) return null;
  const exactOrFuzzy = resolveBusinessRoute(message);
  if (exactOrFuzzy.routeId && exactOrFuzzy.match !== 'signature') {
    return exactOrFuzzy.matchedDirective || exactOrFuzzy.route?.directive || null;
  }
  return BUSINESS_DIRECTIVE_PREFIXES.find((prefix) => line.startsWith(normalizeDirectiveText(prefix))) || null;
}

export function isNewDirectiveMessage(message: string): boolean {
  return detectBusinessDirective(message) !== null;
}