import type { PlayAuthoringInputContract } from './authoring-contract';

function freezeInputSchema(
  schema: Record<string, unknown>,
): Record<string, unknown> {
  const visited = new WeakSet<object>();
  const freeze = (value: unknown): void => {
    if (value === null || typeof value !== 'object' || visited.has(value)) {
      return;
    }
    visited.add(value);
    for (const child of Object.values(value)) freeze(child);
    Object.freeze(value);
  };
  freeze(schema);
  return schema;
}

export function createPlayInputContract<TInput>(
  schema: Record<string, unknown>,
): PlayAuthoringInputContract<TInput> {
  if (!schema || typeof schema !== 'object' || Array.isArray(schema)) {
    throw new Error(
      'defineInput<T>(schema) requires a JSON-schema-like object.',
    );
  }
  return Object.freeze({ schema: freezeInputSchema(schema) });
}