/**
 * @license
 * Copyright 2024 Google LLC
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
import { DataConnectError } from '../core/error';
import { DataConnect } from './DataConnect';
import { OperationRef, QUERY_STR, DataConnectResult, SerializedRef } from './Reference';
/**
 * Signature for `OnResultSubscription` for `subscribe`
 */
export type OnResultSubscription<Data, Variables> = (res: QueryResult<Data, Variables>) => void;
/**
 * Signature for `OnErrorSubscription` for `subscribe`
 */
export type OnErrorSubscription = (err?: DataConnectError) => void;
/**
 * Signature for unsubscribe from `subscribe`
 */
export type QueryUnsubscribe = () => void;
/**
 * Representation of user provided subscription options.
 */
export interface DataConnectSubscription<Data, Variables> {
    userCallback: OnResultSubscription<Data, Variables>;
    errCallback?: (e?: DataConnectError) => void;
    unsubscribe: () => void;
}
/**
 * QueryRef object
 */
export interface QueryRef<Data, Variables> extends OperationRef<Data, Variables> {
    refType: typeof QUERY_STR;
}
/**
 * Result of `executeQuery`
 */
export interface QueryResult<Data, Variables> extends DataConnectResult<Data, Variables> {
    ref: QueryRef<Data, Variables>;
    toJSON: () => SerializedRef<Data, Variables>;
}
/**
 * Promise returned from `executeQuery`
 */
export interface QueryPromise<Data, Variables> extends Promise<QueryResult<Data, Variables>> {
}
/**
 * Execute Query
 * @param queryRef query to execute.
 * @returns `QueryPromise`
 */
export declare function executeQuery<Data, Variables>(queryRef: QueryRef<Data, Variables>): QueryPromise<Data, Variables>;
/**
 * Execute Query
 * @param dcInstance Data Connect instance to use.
 * @param queryName Query to execute
 * @returns `QueryRef`
 */
export declare function queryRef<Data>(dcInstance: DataConnect, queryName: string): QueryRef<Data, undefined>;
/**
 * Execute Query
 * @param dcInstance Data Connect instance to use.
 * @param queryName Query to execute
 * @param variables Variables to execute with
 * @returns `QueryRef`
 */
export declare function queryRef<Data, Variables>(dcInstance: DataConnect, queryName: string, variables: Variables): QueryRef<Data, Variables>;
/**
 * Converts serialized ref to query ref
 * @param serializedRef ref to convert to `QueryRef`
 * @returns `QueryRef`
 */
export declare function toQueryRef<Data, Variables>(serializedRef: SerializedRef<Data, Variables>): QueryRef<Data, Variables>;
/**
 * `OnCompleteSubscription`
 */
export type OnCompleteSubscription = () => void;
/**
 * Representation of full observer options in `subscribe`
 */
export interface SubscriptionOptions<Data, Variables> {
    onNext?: OnResultSubscription<Data, Variables>;
    onErr?: OnErrorSubscription;
    onComplete?: OnCompleteSubscription;
}