/**
 * @license
 * Copyright 2017 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 { Path } from '../util/Path';
import { Index } from './indexes/Index';
/**
 * Node is an interface defining the common functionality for nodes in
 * a DataSnapshot.
 *
 * @interface
 */
export interface Node {
    /**
     * Whether this node is a leaf node.
     * @returns Whether this is a leaf node.
     */
    isLeafNode(): boolean;
    /**
     * Gets the priority of the node.
     * @returns The priority of the node.
     */
    getPriority(): Node;
    /**
     * Returns a duplicate node with the new priority.
     * @param newPriorityNode - New priority to set for the node.
     * @returns Node with new priority.
     */
    updatePriority(newPriorityNode: Node): Node;
    /**
     * Returns the specified immediate child, or null if it doesn't exist.
     * @param childName - The name of the child to retrieve.
     * @returns The retrieved child, or an empty node.
     */
    getImmediateChild(childName: string): Node;
    /**
     * Returns a child by path, or null if it doesn't exist.
     * @param path - The path of the child to retrieve.
     * @returns The retrieved child or an empty node.
     */
    getChild(path: Path): Node;
    /**
     * Returns the name of the child immediately prior to the specified childNode, or null.
     * @param childName - The name of the child to find the predecessor of.
     * @param childNode - The node to find the predecessor of.
     * @param index - The index to use to determine the predecessor
     * @returns The name of the predecessor child, or null if childNode is the first child.
     */
    getPredecessorChildName(childName: string, childNode: Node, index: Index): string | null;
    /**
     * Returns a duplicate node, with the specified immediate child updated.
     * Any value in the node will be removed.
     * @param childName - The name of the child to update.
     * @param newChildNode - The new child node
     * @returns The updated node.
     */
    updateImmediateChild(childName: string, newChildNode: Node): Node;
    /**
     * Returns a duplicate node, with the specified child updated.  Any value will
     * be removed.
     * @param path - The path of the child to update.
     * @param newChildNode - The new child node, which may be an empty node
     * @returns The updated node.
     */
    updateChild(path: Path, newChildNode: Node): Node;
    /**
     * True if the immediate child specified exists
     */
    hasChild(childName: string): boolean;
    /**
     * @returns True if this node has no value or children.
     */
    isEmpty(): boolean;
    /**
     * @returns The number of children of this node.
     */
    numChildren(): number;
    /**
     * Calls action for each child.
     * @param action - Action to be called for
     * each child.  It's passed the child name and the child node.
     * @returns The first truthy value return by action, or the last falsey one
     */
    forEachChild(index: Index, action: (a: string, b: Node) => void): unknown;
    /**
     * @param exportFormat - True for export format (also wire protocol format).
     * @returns Value of this node as JSON.
     */
    val(exportFormat?: boolean): unknown;
    /**
     * @returns hash representing the node contents.
     */
    hash(): string;
    /**
     * @param other - Another node
     * @returns -1 for less than, 0 for equal, 1 for greater than other
     */
    compareTo(other: Node): number;
    /**
     * @returns Whether or not this snapshot equals other
     */
    equals(other: Node): boolean;
    /**
     * @returns This node, with the specified index now available
     */
    withIndex(indexDefinition: Index): Node;
    isIndexed(indexDefinition: Index): boolean;
}
export declare class NamedNode {
    name: string;
    node: Node;
    constructor(name: string, node: Node);
    static Wrap(name: string, node: Node): NamedNode;
}