/**
 * Canonical JSON serialization: sorted keys at every level, 2-space indent, trailing newline.
 */

export type JsonPrimitive = string | number | boolean | null;
export type JsonValue = JsonPrimitive | JsonValue[] | { [key: string]: JsonValue };

function sortKeys(value: unknown): unknown {
  if (value === null || typeof value !== 'object') return value;
  if (Array.isArray(value)) return value.map(sortKeys);
  const sorted: Record<string, unknown> = {};
  for (const key of Object.keys(value as Record<string, unknown>).sort()) {
    sorted[key] = sortKeys((value as Record<string, unknown>)[key]);
  }
  return sorted;
}

export function stringifyCanonical(value: unknown): string {
  return JSON.stringify(sortKeys(value), null, 2) + '\n';
}