// src/shared/prop-schema.ts

/** One field of a block's prop schema. */
export interface PropSchemaEntry {
  /** Default value, used when the incoming data omits this key. */
  default: unknown;
  /** Optional allowed values (advisory; not enforced at runtime in v1). */
  values?: readonly unknown[];
}

/**
 * Declarative data shape. The keys here are EXACTLY the keys `save()` returns to
 * Yjs — this closes the per-key-sync key-resurrection gap (a cleared field is
 * written as its explicit default, never dropped).
 */
export type PropSchema = Record<string, PropSchemaEntry>;

/**
 * Fill a data object against the schema: every schema key present, incoming
 * value when defined else the schema default, and ONLY schema keys (so `save()`
 * is never partial). Returns a frozen plain object — safe to hand straight to
 * core's per-key Yjs sync.
 */
export const fillDefaults = <Data>(
  schema: PropSchema,
  data: Record<string, unknown>
): Readonly<Data> => {
  const result: Record<string, unknown> = {};

  for (const key of Object.keys(schema)) {
    result[key] = data[key] !== undefined ? data[key] : schema[key].default;
  }

  return Object.freeze(result) as Readonly<Data>;
};