import { DocumentSnapshot, QuerySnapshot } from '../snapshot';
import { MetaType } from '../metaTypeCreator';
import { Query, DocumentReference, CollectionGroup } from '../refs';
import { Unsubscribe } from '../alias';
export type OnSnapshot = {
    /**
     * listen to filtered collection, entire collection or single document
     *
     * Attaches a listener for {@link DocumentSnapshot} Or {@link QuerySnapshot} events. You may either pass
     * individual {@link onNext} and {@link onError} callbacks. The listener can be cancelled by
     * calling the function that is returned when {@link OnSnapshot} is called.
     *
     * related documentation:
     *  - {@link https://firelordjs.com/firelord/quick_start#onsnapshot}
     *
     * @param reference
     *
     * Type 1: {@link Query} eg: query(example.collection(...), ...) listen to filtered collection
     *
     * Type 2: {@link CollectionGroup} eg: query(example.collectionGroup(...), ...) listen to filtered {@link Query}
     *
     * Type 3: {@link CollectionReference} eg: example.collection(...) listen to entire collection
     *
     * Type 4: {@link CollectionGroup} reference eg: example.collectionGroup(...) listen to entire {@link Query}
     *
     * Type 5: {@link DocumentReference} eg: example.doc(...) listen to a single document
     * @param onNext - A callback to be called every time a new {@link DocumentSnapshot} or {@link QuerySnapshot} is available.
     *
     * Type 1: receive {@link DocumentSnapshot} if {@link reference} is {@link DocumentReference} eg: (value: {@link DocumentSnapshot}) => { handle data here }
     *
     * Type 2: receive {@link QuerySnapshot} if {@link reference} is {@link CollectionGroup} or {@link Query} or {@link CollectionReference} eg: (value: {@link QuerySnapshot}) => { handle data here }
     *
     * @param onError - optional parameter. A callback to be called if the listen fails or is cancelled. No further callbacks will occur. Eg: (error: {@link FirestoreError})=> { handle error here}
     *
     * @returns An unsubscribe function that can be called to cancel
     * the snapshot listener.
     */
    <T extends MetaType, Ref extends Query<T> | DocumentReference<T>>(reference: Ref extends never ? Ref : Query<T> | DocumentReference<T>, onNext: (snapshot: Ref extends DocumentReference<T> ? DocumentSnapshot<T> : QuerySnapshot<T>) => void | Promise<void>, onError?: (error: Error) => void | Promise<void>): Unsubscribe;
};
export type DummyOnSnapshot = CollectionGroup<MetaType>;