import { GraphNode, NodeDefinition, NodeLike, StatefulGraphNode, StatefulNodeDefinition, StatefulNodeType } from '../../types/graph';
import { DisposeCallback } from '../../utils/store';
import { FieldSetDefinition } from './fields';
/**
 * An instance of the [[query]] node.
 * See the [[query]] documentation to find out more.
 */
export interface QueryNode extends StatefulGraphNode<'query', QueryNodeProperties> {
}
/**
 * A definition of the [[query]] node.
 * See the [[query]] documentation to find out more.
 */
export interface QueryNodeDefinition extends StatefulNodeDefinition<'query', QueryNodeProperties> {
}
export interface QueryNodeOptions {
    omitNils: boolean;
}
export interface QueryNodeProperties {
    keys: NodeDefinition;
    options: QueryNodeOptions;
    root: NodeDefinition;
}
export interface QueryNodeState {
    result: NodeDefinition | GraphNode;
}
export interface QueryNodeData {
    disposeQuerySetSubscription: DisposeCallback | undefined;
}
/**
 * The implementation of the [[query]] node.
 * See the [[query]] documentation to learn more.
 */
export declare const QueryNodeType: StatefulNodeType<'query', QueryNodeProperties>;
/**
 * Creates an instance of a [[query]] node, which is a node used to request values from multiple [[NodeDefinition]]s at a time.
 * This node is used internally by Muster-React when creating bindings between components and the graph.
 * See Muster-React for more information.
 *
 * By default, the [[query]] waits for every field to resolve to a non-dynamic node.
 * This behaviour can be modified through the use of the [[isPending]] and the [[defer]].
 *
 * A [[query]] resolves into a [[tree]], an [[array]] or a [[value]] (depending on
 * the type of the query made). These can be easily converted into plain JS objects
 * with the [[valueOf]] helper. This conversion is reversible through the use of
 * [[toNode]] helper.
 *
 *
 * @example **Basic query**
 * ```js
 * import muster, { key, query, root, valueOf } from '@dws/muster';
 *
 * const app = muster({
 *   firstName: 'Rosalind',
 *   lastName: 'Franklin',
 *   dateOfBirth: 1948,
 * });
 *
 * const user = await app.resolve(query(root(), {
 *   userFirstName: key('firstName'),
 *   lastName: key('lastName'),
 * }));
 * // user = {
 * //   userFirstName: 'Rosalind',
 * //   lastName: 'Franklin',
 * // }
 * ```
 * This example shows how to use a [[query]] to request two [[NodeDefinition]] at the same
 * time. The `query` call consists of: the first argument which defines the graph starting point from which
 * query should begin the traversal; and the second argument, an object (implicitly cast to a [[fields]]) which
 * defines a map of fields to retrieve from the graph. The name of each property in that map
 * corresponds to the name in the output [[tree]]. Note that this name does not have to be the same
 * as the name in the [[key]] on the right of that property. Take the `firstName` graph node
 * and its corresponding `userFirstName` name in the query. The ability to override the name of a
 * node is useful especially when a given [[NodeDefinition]] can be accessed in more than one way.
 * This behaviour is used extensively by the [[proxy]], and by extension the [[remote]], when
 * building a query to a remote node.
 *
 * The [[key]] used in this query defines the name of a given node in the graph. Additionally, the
 * [[key]] can define a map of child nodes to retrieve from that node. See the "**Getting values of
 * nested nodes**" example for more information.
 *
 * A [[query]] resolves into a combination of [[tree]]s, [[array]]s and [[value]]s.
 * This means an output of one query can be used as an input for another [[NodeDefinition]] and even
 * another [[query]].
 *
 *
 * @example **Getting async values**
 * ```js
 * import muster, { fromPromise, key, query, root } from '@dws/muster';
 *
 * let resolvePromise1;
 * const app = muster({
 *   name: 'sync name',
 *   asyncName: fromPromise(() =>
 *     new Promise((res) => resolvePromise1 = res)
 *       .then(() => 'async name'),
 *   ),
 * });
 *
 * console.log('Making the query');
 * app.resolve(query(root(), {
 *   name: key('name'),
 *   asyncName: key('asyncName'),
 * })).subscribe((res) => {
 *   console.log(res);
 * });
 *
 * console.log('Resolving the promise');
 * resolvePromise1();
 *
 * // Console output:
 * // Making the query
 * // Resolving the promise
 * // {
 * //   name: 'sync name',
 * //   asyncName: 'async name',
 * // }
 * ```
 * The [[query]] by default waits for every part of the query to resolve to a non-pending and
 * non-dynamic value. This example demonstrates this behaviour with the help of [[fromPromise]].
 * Note that the query output gets logged only once - after the promise is resolved. Muster can
 * also mark certain parts of the query with [[defer]]s. This instructs Muster
 * to return the query result even if that part of the query is loading. See the "**Defer part of the
 * query**" example for more information.
 *
 *
 * @example **Getting values of nested nodes**
 * ```js
 * import muster, { key, query, root } from '@dws/muster';
 *
 * const app = muster({
 *   user: {
 *     firstName: 'Rosalind',
 *     lastName: 'Franklin',
 *   },
 * });
 *
 * const user = await app.resolve(query(root(), {
 *   user: key('user', {
 *     firstName: key('firstName'),
 *   }),
 * }));
 * // user = {
 * //   user: {
 * //     firstName: 'Rosalind',
 * //   },
 * // }
 * ```
 * The [[query]] can extract values from nested [[NodeDefinition]]s. As shown
 * in the previous example, the [[query]] factory function performs an implicit conversion to a
 * [[fields]]. This saves developers from having to explicitly write unnecessarily verbose code.
 * The same functionality is available in the [[key]]. When the factory is
 * called with a pure JS object, it will recursively cast it to a [[fields]].
 *
 * Sometimes, the second argument to the [[key]] won't be a pure JS object. For
 * example, when a developer wants to get items from a collection. [[fields]] lets the
 * query know that a target [[NodeDefinition]] is expected to be a container-like node. This assumption
 * breaks apart when requesting a collection. To request items from collections, one has to make a
 * query with an [[entries]] instead of a [[fields]]. See the "**Getting atomic items from a
 * collection**" example to find out more.
 *
 *
 * @example **Getting atomic items from a collection**
 * ```js
 * import muster, { entries, key, query, root } from '@dws/muster';
 *
 * const app = muster({
 *   numbers: [1, 2, 3, 4],
 * });
 *
 * const numbers = await app.resolve(query(root(), {
 *   numbers: key('numbers', entries()),
 * }));
 * // numbers = {
 * //   numbers: [1, 2, 3, 4],
 * // }
 * ```
 * An [[entries]] can be provided instead of a [[fields]] to instruct the [[query]] to retrieve
 * all items from a given graph node. In this example, we had it easy: every item is an atomic
 * value. The fun with [[query]]s and collections does not end here. See the "**Getting specific
 * fields from items**" example to learn more about selecting certain fields from items.
 *
 *
 * @example **Getting specific fields from items**
 * ```js
 * import muster, { entries, key, query, ref } from '@dws/muster';
 *
 * const app = muster({
 *   books: [
 *     { name: 'The Expeditionary Force', author: 'Craig Alanson' },
 *     { name: 'Fear The Sky', author: 'Stephen Moss' },
 *     { name: 'After It Happened', author: 'Devon Ford' },
 *   ],
 * });
 *
 * const bookNames = await app.resolve(query(ref('books'), entries({
 *   name: key('name'),
 * })));
 * // bookNames = [
 * //   { name: 'The Expeditionary Force' },
 * //   { name: 'Fear The Sky' },
 * //   { name: 'After It Happened' },
 * // ]
 * ```
 * In this example, apart from getting just a selected field from each item in the collection, we
 * demonstrated another feature of the [[query]]: changing its starting point.
 * In all previous examples, we've used a [[root]] as the starting point of the query, but this time
 * to make the output shorter we've changed it to a `books` collection.
 *
 *
 * @example **Creating setters**
 * ```js
 * import muster, {
 *   createSetter,
 *   key,
 *   query,
 *   root,
 *   variable,
 * } from '@dws/muster';
 *
 * const app = muster({
 *   name: variable('initial'),
 * });
 *
 * console.log('Making a query for `name`');
 * app.resolve(query(root(), { name: key('name') })).subscribe((result) => {
 *   console.log(result);
 * });
 *
 * console.log('Making a query for setter function');
 * const result = await app.resolve(query(root(), {
 *   setName: createSetter('name'),
 * }));
 *
 * console.log('Calling a setter');
 * result.setName('updated');
 *
 * // Console output:
 * // Making a query for `name`
 * // initial
 * // Making a query for setter function
 * // Calling a setter
 * // updated
 * ```
 * This example shows how a [[query]] can be used when there's a need for imperative call
 * to a set method. This setter function can be used, for example,
 * when integrating with view frameworks such as React, Vue etc.
 * Muster-React uses this way of creating setters extensively. Similarly, there's a
 * [[createCaller]] node which allows for imperative calls to actions.
 *
 * [[createSetter]]s and [[createCaller]]s should be used only when the output of the query
 * is used outside the "Muster world". Inside Muster code, using [[call]]s
 * [[apply]]s and [[set]]s is recommended for these kinds of actions.
 *
 *
 * @example **Defer part of a query**
 * ```js
 * import muster, { defer, fromPromise, key, query, root } from '@dws/muster';
 *
 * let resolvePromise2;
 * const app = muster({
 *   name: 'sync name',
 *   asyncName: fromPromise(() =>
 *     new Promise((res) => resolvePromise2 = res)
 *       .then(() => 'async name'),
 *   ),
 * });
 *
 * console.log('Requesting the query');
 * app.resolve(query(root(), {
 *   name: key('name'),
 *   asyncName: defer('asyncName'),
 * })).subscribe((res) => {
 *   console.log(res);
 * });
 *
 * console.log('Resolving the promise');
 * resolvePromise2();
 *
 * // Console output:
 * // Requesting the query
 * // {
 * //   name: 'sync name',
 * //   asyncName: null,
 * // }
 * // Resolving the promise
 * // {
 * //   name: 'sync name',
 * //   asyncName: 'async name',
 * // }
 * ```
 * This example demonstrates how to instruct a [[query]] to return the output of its query
 * even if a given [[NodeDefinition]] is in a pending state. The query is built with a
 * [[defer]]. This example uses a shorthand syntax for the `defer(...)` node.
 * Internally, the node converts the argument to a [[key]]:
 * ```js
 * import { defer, key } from '@dws/muster';
 *
 * defer('asyncName');
 * // is equivalent to
 * defer(key('name'));
 * ```
 * The [[defer]] also enables the defer part of the query to return a previously loaded
 * (stale) value of the target node. See the "**Defer with previous value**" example for more
 * information.
 *
 *
 * @example **Check if defer part of the query is loading**
 * ```js
 * import muster, {
 *   defer,
 *   fromPromise,
 *   isPending,
 *   key,
 *   query,
 *   root,
 * } from '@dws/muster';
 *
 * let resolvePromise3;
 * const app = muster({
 *   name: 'sync name',
 *   asyncName: fromPromise(() =>
 *     new Promise((res) => resolvePromise3 = res)
 *       .then(() => 'async name'),
 *   ),
 * });
 *
 * console.log('Requesting the query');
 * app.resolve(query(root(), {
 *   name: key('name'),
 *   asyncName: defer('asyncName'),
 *   isLoadingAsyncName: isPending('asyncName'),
 * })).subscribe((res) => {
 *   console.log(res);
 * });
 *
 * console.log('Resolving the promise');
 * resolvePromise3();
 *
 * // Console output:
 * // Requesting the query
 * // {
 * //   name: 'sync name',
 * //   asyncName: null,
 * //   isLoadingAsyncName: true,
 * // }
 * // Resolving the promise
 * // {
 * //   name: 'sync name',
 * //   asyncName: 'async name',
 * //   isLoadingAsyncName: false,
 * // }
 * ```
 * This example presents the use of the [[isPending]]. When used in a query, this node checks if
 * a part of the query is currently loading. Similarly to the [[defer]],
 * the [[isPending]] factory function implicitly converts its argument to a [[key]].
 * ```js
 * import { isPending, key } from '@dws/muster';
 *
 * isPending('asyncName');
 * // is equivalent to
 * isPending(key('asyncName'))
 * ```
 */
export declare function query(root: NodeLike, keys: NodeDefinition | FieldSetDefinition, options?: Partial<QueryNodeOptions>): QueryNodeDefinition;
export declare function isQueryNodeDefinition(value: NodeDefinition): value is QueryNodeDefinition;