import { sourceFetchData } from '@wix/bex-core';
import type {
  FiltersMap,
  OffsetQuery,
  OffsetQueryResult,
  SchemaSource,
} from '@wix/bex-core';
import type { CollectionConfigWithConditionals } from '@wix/bex-core/react';

type FetchData<T> = (query: OffsetQuery) => Promise<OffsetQueryResult<T>>;

/**
 * The collection options a schema-entry hook accepts — everything the source
 * doesn't supply. Source-owned keys (`queryName`, `paginationMode`,
 * `fetchData`, `fetchTotal`, `itemKey`, `itemName`) don't exist here.
 */
export type SchemaCollectionOptions<T, F extends FiltersMap> = Omit<
  CollectionConfigWithConditionals<T, F>,
  | 'queryName'
  | 'paginationMode'
  | 'fetchData'
  | 'fetchTotal'
  | 'itemKey'
  | 'itemName'
> & {
  /** Wraps the source's fetch (filter/enrich results) without replacing it. */
  wrapFetchData?: (next: FetchData<T>) => FetchData<T>;
};

/** Builds the collection config from the source: the query fetches through the
 *  source's backend, identity and labels come from the source, and the
 *  consumer's options fill the rest.
 *  `options` is typed loosely — the hooks' option types already enforce the
 *  consumer surface, and TS can't infer `F` back through the conditional
 *  config type; callers pass the generics explicitly. */
export function schemaCollectionConfig<T, F extends FiltersMap>(
  source: SchemaSource<T>,
  options?: object,
): CollectionConfigWithConditionals<T, F> {
  const { wrapFetchData, ...rest } = (options ?? {}) as SchemaCollectionOptions<
    T,
    F
  >;
  const fetchData = sourceFetchData(source);
  return {
    ...rest,
    queryName: source.collectionId,
    paginationMode: source.paginationMode,
    fetchData: wrapFetchData ? wrapFetchData(fetchData) : fetchData,
    itemKey: source.itemKey,
    itemName: source.itemName,
  } as unknown as CollectionConfigWithConditionals<T, F>;
}