import {QueryConstraint} from 'firebase/firestore';

/**
 * For Listening to a Document and multiple sub Collections in that Document
 */

export interface SubCollectionQuery {

  /** the name of the subCollection to be read. */
  name: string;

  /** Specified Document name if multiple documents in collection is not used */
  docId?: string;

  /** Any SubCollections to be read in the Collection */
  subCollections?: SubCollectionQuery[];

  /**
   *
   * The Collection QueryConstraint.
   *
   * In Firebase v.9 the queryFn was replaced with QueryConstraint
   *
   * Firebase v.9 Example:
   * queryConstraints: [
   *    where('type', '==', 'Book'),
   *    where('price', '>' 18.00),
   *    where(price', '<' 100.00),
   *    where('category', '==', 'Fiction'),
   *    where('publisher', '==', 'BigPublisher'),
   *    orderBy('price'),
   * ]
   *
   *
   * Old Example < Firebase v.9 version:
   * queryFn = ref.where('type', '==', 'Book')
   *              .where('price', '>' 18.00)
   *              .where('price', '<' 100.00)
   *              .where('category', '==', 'Fiction')
   *              .where('publisher', '==', 'BigPublisher')
   *
   */
  queryConstraints?: QueryConstraint[];
}