/*!
 * Copyright 2018 Google Inc. All Rights Reserved.
 *
 * 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 * as firestore from '@google-cloud/firestore';
import { QueryDocumentSnapshot } from './document';
export declare type DocumentChangeType = 'added' | 'removed' | 'modified';
/**
 * A DocumentChange represents a change to the documents matching a query.
 * It contains the document affected and the type of change that occurred.
 *
 * @class DocumentChange
 */
export declare class DocumentChange<T = firestore.DocumentData> implements firestore.DocumentChange<T> {
    private readonly _type;
    private readonly _document;
    private readonly _oldIndex;
    private readonly _newIndex;
    /**
     * @private
     *
     * @param {string} type 'added' | 'removed' | 'modified'.
     * @param {QueryDocumentSnapshot} document The document.
     * @param {number} oldIndex The index in the documents array prior to this
     * change.
     * @param {number} newIndex The index in the documents array after this
     * change.
     */
    constructor(type: DocumentChangeType, document: QueryDocumentSnapshot<T>, oldIndex: number, newIndex: number);
    /**
     * The type of change ('added', 'modified', or 'removed').
     *
     * @type {string}
     * @name DocumentChange#type
     * @readonly
     *
     * @example
     * ```
     * let query = firestore.collection('col').where('foo', '==', 'bar');
     * let docsArray = [];
     *
     * let unsubscribe = query.onSnapshot(querySnapshot => {
     *   for (let change of querySnapshot.docChanges) {
     *     console.log(`Type of change is ${change.type}`);
     *   }
     * });
     *
     * // Remove this listener.
     * unsubscribe();
     * ```
     */
    get type(): DocumentChangeType;
    /**
     * The document affected by this change.
     *
     * @type {QueryDocumentSnapshot}
     * @name DocumentChange#doc
     * @readonly
     *
     * @example
     * ```
     * let query = firestore.collection('col').where('foo', '==', 'bar');
     *
     * let unsubscribe = query.onSnapshot(querySnapshot => {
     *   for (let change of querySnapshot.docChanges) {
     *     console.log(change.doc.data());
     *   }
     * });
     *
     * // Remove this listener.
     * unsubscribe();
     * ```
     */
    get doc(): QueryDocumentSnapshot<T>;
    /**
     * The index of the changed document in the result set immediately prior to
     * this DocumentChange (i.e. supposing that all prior DocumentChange objects
     * have been applied). Is -1 for 'added' events.
     *
     * @type {number}
     * @name DocumentChange#oldIndex
     * @readonly
     *
     * @example
     * ```
     * let query = firestore.collection('col').where('foo', '==', 'bar');
     * let docsArray = [];
     *
     * let unsubscribe = query.onSnapshot(querySnapshot => {
     *   for (let change of querySnapshot.docChanges) {
     *     if (change.oldIndex !== -1) {
     *       docsArray.splice(change.oldIndex, 1);
     *     }
     *     if (change.newIndex !== -1) {
     *       docsArray.splice(change.newIndex, 0, change.doc);
     *     }
     *   }
     * });
     *
     * // Remove this listener.
     * unsubscribe();
     * ```
     */
    get oldIndex(): number;
    /**
     * The index of the changed document in the result set immediately after
     * this DocumentChange (i.e. supposing that all prior DocumentChange
     * objects and the current DocumentChange object have been applied).
     * Is -1 for 'removed' events.
     *
     * @type {number}
     * @name DocumentChange#newIndex
     * @readonly
     *
     * @example
     * ```
     * let query = firestore.collection('col').where('foo', '==', 'bar');
     * let docsArray = [];
     *
     * let unsubscribe = query.onSnapshot(querySnapshot => {
     *   for (let change of querySnapshot.docChanges) {
     *     if (change.oldIndex !== -1) {
     *       docsArray.splice(change.oldIndex, 1);
     *     }
     *     if (change.newIndex !== -1) {
     *       docsArray.splice(change.newIndex, 0, change.doc);
     *     }
     *   }
     * });
     *
     * // Remove this listener.
     * unsubscribe();
     * ```
     */
    get newIndex(): number;
    /**
     * Returns true if the data in this `DocumentChange` is equal to the provided
     * value.
     *
     * @param {*} other The value to compare against.
     * @return true if this `DocumentChange` is equal to the provided value.
     */
    isEqual(other: firestore.DocumentChange<T>): boolean;
}
