/* eslint-disable import/no-duplicates */
/*
 * Copyright (c) 2016-present Invertase Limited & Contributors
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this library 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 type { ReactNativeFirebaseModule } from '@react-native-firebase/app-types/index.js.flow';

/**
 * An immutable object representing an array of bytes.
 */
export class Blob {
  /**
   * Creates a new Blob from the given Base64 string, converting it to bytes.
   *
   * @param base64 The Base64 string used to create the Blob object.
   */
  static fromBase64String: (base64: string) => Blob;

  /**
   * Creates a new Blob from the given Uint8Array.
   *
   * @param array The Uint8Array used to create the Blob object.
   */
  static fromUint8Array: (array: Uint8Array) => Blob;

  /**
   * Returns true if this `Blob` is equal to the provided one.
   *
   * @param other The `Blob` to compare against.
   */
  isEqual: (other: Blob) => boolean;

  /**
   * Returns the bytes of a Blob as a Base64-encoded string.
   */
  toBase64: () => string;

  /**
   * Returns the bytes of a Blob in a new Uint8Array.
   */
  toUint8Array: () => Uint8Array;
}

/**
 * A `CollectionReference` object can be used for adding documents, getting document references, and querying for
 * documents (using the methods inherited from `Query`).
 */
export interface CollectionReference extends Query {
  /**
   * The collection's identifier.
   */
  id: string;

  /**
   * A reference to the containing `DocumentReference` if this is a subcollection. If this isn't a
   * subcollection, the reference is null.
   */
  parent: DocumentReference | null;

  /**
   * A string representing the path of the referenced collection (relative to the root of the database).
   */
  path: string;

  /**
   * Add a new document to this collection with the specified data, assigning it a document ID automatically.
   *
   * #### Example
   *
   * ```js
   * const documentRef = await firebase.firestore().collection('users').add({
   *   name: 'Ada Lovelace',
   *   age: 30,
   * });
   * ```
   *
   * @param data An Object containing the data for the new document.
   */
  add(data: { [key]: value }): Promise<DocumentReference>;

  /**
   * Get a DocumentReference for the document within the collection at the specified path. If no
   * path is specified, an automatically-generated unique ID will be used for the returned DocumentReference.
   *
   * #### Example
   *
   * ```js
   * await firebase.firestore().collection('users').doc('alovelace').set({
   *   name: 'Ada Lovelace',
   *   age: 30,
   * });
   * ```
   *
   * @param documentPath A slash-separated path to a document.
   */
  doc(documentPath?: string): DocumentReference;
}

/**
 * A DocumentChange represents a change to the documents matching a query. It contains the document affected and the
 * type of change that occurred.
 */
export interface DocumentChange {
  /**
   * The document affected by this change.
   */
  doc: DocumentSnapshot;

  /**
   * 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.
   */
  newIndex: number;

  /**
   * 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.
   */
  oldIndex: number;

  /**
   * The type of change ('added', 'modified', or 'removed').
   */
  type: DocumentChangeType;
}

/**
 * The type of a DocumentChange may be 'added', 'removed', or 'modified'.
 */
export type DocumentChangeType = 'added' | 'removed' | 'modified';

/**
 * A `DocumentReference` refers to a document location in a Firestore database and can be used to write, read, or listen
 * to the location. The document at the referenced location may or may not exist. A `DocumentReference` can also be used
 * to create a `CollectionReference` to a subcollection.
 */
export interface DocumentReference {
  /**
   * The Firestore instance the document is in. This is useful for performing transactions, for example.
   */
  firestore: Module;

  /**
   * The document's identifier within its collection.
   */
  id: string;

  /**
   * The Collection this `DocumentReference` belongs to.
   */
  parent: CollectionReference;

  /**
   * A string representing the path of the referenced document (relative to the root of the database).
   */
  path: string;

  /**
   * Gets a `CollectionReference` instance that refers to the collection at the specified path.
   *
   * #### Example
   *
   * ```js
   * const collectionRef = firebase.firestore().doc('users/alovelace').collection('orders');
   * ```
   *
   * @param collectionPath A slash-separated path to a collection.
   */
  collection(collectionPath: string): CollectionReference;

  /**
   * Deletes the document referred to by this DocumentReference.
   *
   * #### Example
   *
   * ```js
   * await firebase.firestore().doc('users/alovelace').delete();
   * ```
   *
   * The Promise is resolved once the document has been successfully deleted from the backend
   * (Note that it won't resolve while you're offline).
   */
  delete(): Promise<void>;

  /**
   * Reads the document referred to by this DocumentReference.
   *
   * Note: By default, get() attempts to provide up-to-date data when possible by waiting for data
   * from the server, but it may return cached data or fail if you are offline and the server cannot
   * be reached. This behavior can be altered via the GetOptions parameter.
   *
   * #### Example
   *
   * ```js
   * await firebase.firestore().doc('users/alovelace').get({
   *   source: 'server',
   * });
   * ```
   *
   * @param options An object to configure the get behavior.
   */
  get(options?: GetOptions): Promise<DocumentSnapshot>;

  /**
   * Returns true if this DocumentReference is equal to the provided one.
   *
   * #### Example
   *
   * ```js
   * const alovelace = firebase.firestore().doc('users/alovelace');
   * const dsmith = firebase.firestore().doc('users/dsmith');
   *
   * // false
   * alovelace.isEqual(dsmith);
   * ``
   *
   * @param other The `DocumentReference` to compare against.
   */
  isEqual(other: DocumentReference): boolean;

  /**
   * Attaches a listener for DocumentSnapshot events.
   *
   * NOTE: Although an complete callback can be provided, it will never be called because the snapshot stream is never-ending.
   *
   * Returns an unsubscribe function to stop listening to events.
   *
   * #### Example
   *
   * ```js
   * const unsubscribe = firebase.firestore().doc('users/alovelace')
   *   .onSnapshot({
   *     error: (e) => console.error(e),
   *     next: (documentSnapshot) => {},
   *   });
   *
   * unsubscribe();
   * ```
   *
   * @param observer A single object containing `next` and `error` callbacks.
   */
  onSnapshot(observer: { complete?: Function, error?: Function, next?: Function }): Function;

  /**
   * Attaches a listener for DocumentSnapshot events with snapshot listener options.
   *
   * NOTE: Although an complete callback can be provided, it will never be called because the snapshot stream is never-ending.
   *
   * Returns an unsubscribe function to stop listening to events.
   *
   * #### Example
   *
   * ```js
   * const unsubscribe = firebase.firestore().doc('users/alovelace')
   *   .onSnapshot({
   *     includeMetadataChanges: true,
   *   }, {
   *     error: (e) => console.error(e),
   *     next: (documentSnapshot) => {},
   *   });
   *
   * unsubscribe();
   * ```
   *
   * @param options Options controlling the listen behavior.
   * @param observer A single object containing `next` and `error` callbacks.
   */
  onSnapshot(
    options: SnapshotListenOptions,
    observer: { complete?: Function, error?: Function, next?: Function },
  ): Function;

  /**
   * Attaches a listener for DocumentSnapshot events.
   *
   * NOTE: Although an onCompletion callback can be provided, it will never be called because the snapshot stream is never-ending.
   *
   * Returns an unsubscribe function to stop listening to events.
   *
   * #### Example
   *
   * ```js
   * const unsubscribe = firebase.firestore().doc('users/alovelace')
   *   .onSnapshot(
   *     (documentSnapshot) => {}, // onNext
   *     (error) => console.error(error), // onError
   *   );
   *
   * unsubscribe();
   * ```
   * @param onNext A callback to be called every time a new `DocumentSnapshot` is available.
   * @param onError A callback to be called if the listen fails or is cancelled. No further callbacks will occur.
   * @param onCompletion An optional function which will never be called.
   */
  onSnapshot(onNext: Function, onError?: Function, onCompletion?: Function): Function;

  /**
   * Attaches a listener for DocumentSnapshot events with snapshot listener options.
   *
   * NOTE: Although an onCompletion callback can be provided, it will never be called because the snapshot stream is never-ending.
   *
   * Returns an unsubscribe function to stop listening to events.
   *
   * #### Example
   *
   * ```js
   * const unsubscribe = firebase.firestore().doc('users/alovelace')
   *   .onSnapshot(
   *     { includeMetadataChanges: true }, // SnapshotListenerOptions
   *     (documentSnapshot) => {}, // onNext
   *     (error) => console.error(error), // onError
   *   );
   *
   * unsubscribe();
   * ```
   * @param options Options controlling the listen behavior.
   * @param onNext A callback to be called every time a new `DocumentSnapshot` is available.
   * @param onError A callback to be called if the listen fails or is cancelled. No further callbacks will occur.
   * @param onCompletion An optional function which will never be called.
   */
  onSnapshot(
    options: SnapshotListenOptions,
    onNext: Function,
    onError?: Function,
    onCompletion?: Function,
  ): Function;

  /**
   * Writes to the document referred to by this DocumentReference. If the document does not yet
   * exist, it will be created. If you pass SetOptions, the provided data can be merged into an
   * existing document.
   *
   * #### Example
   *
   * ```js
   * const user = firebase.firestore().doc('users/alovelace');
   *
   * // Set new data
   * await user.set({
   *   name: 'Ada Lovelace',
   *   age: 30,
   *   city: 'LON',
   * });
   * ``
   *
   * @param data A map of the fields and values for the document.
   * @param options An object to configure the set behavior.
   */
  set(data: { [key]: value }, options?: SetOptions): Promise<void>;

  /**
   * Updates fields in the document referred to by this `DocumentReference`. The update will fail
   * if applied to a document that does not exist.
   *
   * #### Example
   *
   * ```
   * const user = firebase.firestore().doc('users/alovelace');
   *
   * // Update age but leave other fields untouched
   * await user.update({
   *   age: 31,
   * });
   * ```
   *
   * @param data An object containing the fields and values with which to update the document. Fields can contain dots to reference nested fields within the document.
   */
  update(data: { [key]: value }): Promise<void>;

  /**
   * Updates fields in the document referred to by this DocumentReference. The update will fail if
   * applied to a document that does not exist.
   *
   * #### Example
   *
   * ```
   * const user = firebase.firestore().doc('users/alovelace');
   *
   * // Update age & city but leve other fields untouched
   * await user.update('age', 31, 'city', 'SF');
   * ```
   *
   * @param field The first field to update.
   * @param value The first value.
   * @param moreFieldsAndValues Additional key value pairs.
   */
  update(field: string | FieldPath, value: any, ...moreFieldsAndValues: any[]): Promise<void>;
}

/**
 * A DocumentSnapshot contains data read from a document in your Firestore database. The data can be extracted with
 * .`data()` or `.get(<field>)` to get a specific field.
 *
 * For a DocumentSnapshot that points to a non-existing document, any data access will return 'undefined'.
 * You can use the `exists` property to explicitly verify a document's existence.
 */
export interface DocumentSnapshot {
  /**
   * Property of the `DocumentSnapshot` that signals whether or not the data exists. True if the document exists.
   */
  exists: boolean;

  /**
   * Property of the `DocumentSnapshot` that provides the document's ID.
   */
  id: string;

  /**
   * Metadata about the `DocumentSnapshot`, including information about its source and local modifications.
   */
  metadata: SnapshotMetadata;

  /**
   * The `DocumentReference` for the document included in the `DocumentSnapshot`.
   */
  ref: DocumentReference;

  /**
   * Retrieves all fields in the document as an Object. Returns 'undefined' if the document doesn't exist.
   *
   * #### Example
   *
   * ```js
   * const user = await firebase.firestore().doc('users/alovelace').get();
   *
   * console.log('User', user.data());
   * ```
   */
  data(): { [key]: value } | undefined;

  /**
   * Retrieves the field specified by fieldPath. Returns undefined if the document or field doesn't exist.
   *
   * #### Example
   *
   * ```js
   * const user = await firebase.firestore().doc('users/alovelace').get();
   *
   * console.log('Address ZIP Code', user.get('address.zip'));
   * ```
   *
   * @param fieldPath The path (e.g. 'foo' or 'foo.bar') to a specific field.
   */
  get(fieldPath: string | FieldPath): any;

  /**
   * Returns true if this `DocumentSnapshot` is equal to the provided one.
   *
   * #### Example
   *
   * ```js
   * const user1 = await firebase.firestore().doc('users/alovelace').get();
   * const user2 = await firebase.firestore().doc('users/dsmith').get();
   *
   * // false
   * user1.isEqual(user2);
   * ```
   *
   * @param other The `DocumentSnapshot` to compare against.
   */
  isEqual(other: DocumentSnapshot): boolean;
}

/**
 * A FieldPath refers to a field in a document. The path may consist of a single field name (referring to a
 * top-level field in the document), or a list of field names (referring to a nested field in the document).
 *
 * Create a FieldPath by providing field names. If more than one field name is provided, the path will point to a nested field in a document.
 *
 * #### Example
 *
 * ```js
 * const user = await firebase.firestore().doc('users/alovelace').get();
 *
 * // Create a new field path
 * const fieldPath = new firebase.firestore.FieldPath('address', 'zip');
 *
 * console.log('Address ZIP Code', user.get(fieldPath));
 * ```
 */
export class FieldPath {
  /**
   * Returns a special sentinel FieldPath to refer to the ID of a document. It can be used in queries to sort or filter by the document ID.
   */
  static documentId: () => FieldPath;

  /**
   * Creates a FieldPath from the provided field names. If more than one field name is provided, the path will point to a nested field in a document.
   *
   * #### Example
   *
   * ```js
   * const fieldPath = new firebase.firestore.FieldPath('address', line', 'one');
   * ```
   *
   * @param fieldNames A list of field names.
   */
  // TODO don't think this is possible on flow?
  // constructor(...fieldNames: string[]);

  /**
   * Returns true if this `FieldPath` is equal to the provided one.
   *
   * #### Example
   *
   * ```js
   * const fieldPath1 = new firebase.firestore.FieldPath('address', 'zip');
   * const fieldPath2 = new firebase.firestore.FieldPath('address', line', 'one');
   *
   * // false
   * fieldPath1.isEqual(fieldPath2);
   * ```
   *
   * @param other The `FieldPath` to compare against.
   */
  isEqual: (other: FieldPath) => boolean;
}

/**
 * Sentinel values that can be used when writing document fields with `set()` or `update()`.
 *
 * #### Example
 *
 * ```js
 * const increment = firebase.firestore.FieldValue.increment(1);
 *
 * await firebase.firestore().doc('users/alovelace).update({
 *   age: increment, // increment age by 1
 * });
 * ```
 */
export class FieldValue {
  /**
   * Returns a special value that can be used with `set()` or `update()` that tells the server to remove the given elements
   * from any array value that already exists on the server. All instances of each element specified will be removed from
   * the array. If the field being modified is not already an array it will be overwritten with an empty array.
   *
   * #### Example
   *
   * ```js
   * const arrayRemove = firebase.firestore.FieldValue.arrayRemove(2, '3');
   *
   * // Removes the values 2 & '3' from the values array on the document
   * await docRef.update({
   *   values: arrayRemove,
   * });
   * ```
   *
   * @param elements The elements to remove from the array.
   */
  static arrayRemove: (...elements: any[]) => FieldValue;

  /**
   * Returns a special value that can be used with `set()` or `update()` that tells the server to union the given
   * elements with any array value that already exists on the server. Each specified element that doesn't already exist
   * in the array will be added to the end. If the field being modified is not already an array it will be overwritten
   * with an array containing exactly the specified elements.
   *
   * #### Example
   *
   * ```js
   * const arrayUnion = firebase.firestore.FieldValue.arrayUnion(2, '3');
   *
   * // Appends the values 2 & '3' onto the values array on the document
   * await docRef.update({
   *   values: arrayUnion,
   * });
   * ```
   *
   * @param elements The elements to union into the array.
   */
  static arrayUnion: (...elements: any[]) => FieldValue;

  /**
   * Returns a sentinel for use with update() to mark a field for deletion.
   *
   * #### Example
   *
   * ```js
   * const delete = firebase.firestore.FieldValue.delete();
   *
   * // Deletes the name field on the document
   * await docRef.update({
   *   name: delete,
   * });
   * ```
   */
  static delete: () => FieldValue;

  /**
   * Returns a special value that can be used with `set()` or `update()` that tells the server to increment the field's current value by the given value.
   *
   * If either the operand or the current field value uses floating point precision, all arithmetic follows IEEE 754 semantics.
   * If both values are integers, values outside of JavaScript's safe number range (`Number.MIN_SAFE_INTEGER` to `Number.MAX_SAFE_INTEGER`)
   * are also subject to precision loss. Furthermore, once processed by the Firestore backend, all integer operations are
   * capped between -2^63 and 2^63-1.
   *
   * If the current field value is not of type `number`, or if the field does not yet exist, the transformation sets the field to the given value.
   *
   * #### Example
   *
   * ```js
   * const increment = firebase.firestore.FieldValue.increment(1);
   *
   * // Increment the loginCount field by 1 on the document
   * await docRef.update({
   *   loginCount: increment,
   * });
   * ```
   *
   * @param n The value to increment by.
   */
  static increment: (n: number) => FieldValue;

  /**
   * Returns a sentinel used with set() or update() to include a server-generated timestamp in the written data.
   *
   * #### Example
   *
   * ```js
   * const timestamp = firebase.firestore.FieldValue.serverTimestamp();
   *
   * // Set the updatedAt field to the current server time
   * await docRef.update({
   *   updatedAt: timestamp,
   * });
   * ```
   */
  static serverTimestamp: () => FieldValue;

  /**
   * Returns true if this FieldValue is equal to the provided one.
   *
   * #### Example
   *
   * ```js
   * const increment = firebase.firestore.FieldValue.increment(1);
   * const timestamp = firebase.firestore.FieldValue.serverTimestamp();
   *
   * // false
   * increment.isEqual(timestamp);
   * ```
   *
   * @param other The FieldValue to compare against.
   */
  isEqual: (other: FieldValue) => boolean;
}

/**
 * An immutable object representing a geo point in Firestore. The geo point is represented as latitude/longitude pair.
 *
 * Latitude values are in the range of [-90, 90]. Longitude values are in the range of [-180, 180].
 */
export class GeoPoint {
  /**
   * Creates a new immutable GeoPoint object with the provided latitude and longitude values.
   *
   * #### Example
   *
   * ```js
   * const geoPoint = new firebase.firestore.GeoPoint(60, -40);
   * ```
   *
   * @param latitude The latitude as number between -90 and 90.
   * @param longitude The longitude as number between -180 and 180.
   */
  // TODO don't think this is possible on flow?
  // constructor(latitude: number, longitude: number);

  /**
   * The latitude of this `GeoPoint` instance.
   */
  latitude: number;

  /**
   * The longitude of this `GeoPoint` instance.
   */
  longitude: number;

  /**
   * Returns true if this `GeoPoint` is equal to the provided one.
   *
   * #### Example
   *
   * ```js
   * const geoPoint1 = new firebase.firestore.GeoPoint(60, -40);
   * const geoPoint2 = new firebase.firestore.GeoPoint(60, -20);
   *
   * // false
   * geoPoint1.isEqual(geoPoint2);
   * ```
   *
   * @param other The `GeoPoint` to compare against.
   */
  isEqual: (other: GeoPoint) => boolean;
}

/**
 * An options object that configures the behavior of get() calls on DocumentReference and Query.
 * By providing a GetOptions object, these methods can be configured to fetch results only from the
 * server, only from the local cache or attempt to fetch results from the server and fall back to the
 * cache (which is the default).
 */
export interface GetOptions {
  /**
   * Describes whether we should get from server or cache.
   *
   * Setting to `default` (or not setting at all), causes Firestore to try to retrieve an up-to-date (server-retrieved)
   * snapshot, but fall back to returning cached data if the server can't be reached.
   *
   * Setting to `server` causes Firestore to avoid the cache, generating an error if the server cannot be reached. Note
   * that the cache will still be updated if the server request succeeds. Also note that latency-compensation still
   * takes effect, so any pending write operations will be visible in the returned data (merged into the server-provided data).
   *
   * Setting to `cache` causes Firestore to immediately return a value from the cache, ignoring the server completely
   * (implying that the returned value may be stale with respect to the value on the server.) If there is no data in the
   * cache to satisfy the `get()` call, `DocumentReference.get()` will return an error and `QuerySnapshot.get()` will return an
   * empty `QuerySnapshot` with no documents.
   */
  source: 'default' | 'server' | 'cache';
}

/**
 * A Query refers to a `Query` which you can read or listen to. You can also construct refined `Query` objects by
 * adding filters and ordering.
 */
export interface Query {
  /**
   * Creates and returns a new Query that ends at the provided document (inclusive). The end
   * position is relative to the order of the query. The document must contain all of the
   * fields provided in the orderBy of this query.
   *
   * #### Example
   *
   * ```js
   * const user = await firebase.firestore().doc('users/alovelace').get();
   *
   * // Get all users up to a specific user in order of age
   * const querySnapshot = await firebase.firestore()
   *   .collection('users')
   *   .orderBy('age')
   *   .endAt(user);
   * ```
   *
   * > Cursor snapshot queries have limitations. Please see [Query limitations](/) for more information.
   *
   * @param snapshot The snapshot of the document to end at.
   */
  endAt(snapshot: DocumentSnapshot): Query;

  /**
   * Creates and returns a new Query that ends at the provided fields relative to the order of the query.
   * The order of the field values must match the order of the order by clauses of the query.
   *
   * #### Example
   *
   * ```js
   * // Get all users who's age is 30 or less
   * const querySnapshot = await firebase.firestore()
   *   .collection('users')
   *   .orderBy('age')
   *   .endAt(30);
   * ```
   *
   * @param fieldValues The field values to end this query at, in order of the query's order by.
   */
  endAt(...fieldValues: any[]): Query;

  /**
   * Creates and returns a new Query that ends before the provided document (exclusive). The end
   * position is relative to the order of the query. The document must contain all of the fields
   * provided in the orderBy of this query.
   *
   * #### Example
   *
   * ```js
   * const user = await firebase.firestore().doc('users/alovelace').get();
   *
   * // Get all users up to, but not including, a specific user in order of age
   * const querySnapshot = await firebase.firestore()
   *   .collection('users')
   *   .orderBy('age')
   *   .endBefore(user);
   * ```
   *
   * > Cursor snapshot queries have limitations. Please see [Query limitations](/) for more information.
   *
   * @param snapshot The snapshot of the document to end before.
   */
  endBefore(snapshot: DocumentSnapshot): Query;

  /**
   * Creates and returns a new Query that ends before the provided fields relative to the order of
   * the query. The order of the field values must match the order of the order by clauses of the query.
   *
   * #### Example
   *
   * ```js
   * // Get all users who's age is 29 or less
   * const querySnapshot = await firebase.firestore()
   *   .collection('users')
   *   .orderBy('age')
   *   .endBefore(30);
   * ```
   *
   * @param fieldValues The field values to end this query before, in order of the query's order by.
   */
  endBefore(...fieldValues: any[]): Query;

  /**
   * Executes the query and returns the results as a QuerySnapshot.
   *
   * Note: By default, get() attempts to provide up-to-date data when possible by waiting for data from the server,
   * but it may return cached data or fail if you are offline and the server cannot be reached. This behavior can be
   * altered via the `GetOptions` parameter.
   *
   * #### Example
   *
   * ```js
   * const querySnapshot = await firebase.firestore()
   *   .collection('users')
   *   .orderBy('age')
   *   .get({
   *     source: 'server',
   *   });
   * ```
   *
   * @param options An object to configure the get behavior.
   */
  get(options?: GetOptions): Promise<QuerySnapshot>;

  /**
   * Returns true if this Query is equal to the provided one.
   *
   * #### Example
   *
   * ```js
   * const query = firebase.firestore()
   *   .collection('users')
   *   .orderBy('age');
   *
   * // false
   * query.isEqual(
   *   firebase.firestore()
   *     .collection('users')
   *     .orderBy('name')
   * );
   * ```
   *
   * @param other The `Query` to compare against.
   */
  isEqual(other: Query): boolean;

  /**
   * Creates and returns a new Query where the results are limited to the specified number of documents.
   *
   * #### Example
   *
   * ```js
   * // Get 10 users in order of age
   * const querySnapshot = firebase.firestore()
   *   .collection('users')
   *   .orderBy('age')
   *   .limit(10)
   *   .get();
   * ```
   *
   * @param limit The maximum number of items to return.
   */
  limit(limit: number): Query;

  /**
   * Attaches a listener for `QuerySnapshot` events.
   *
   * NOTE: Although an complete callback can be provided, it will never be called because the snapshot stream is never-ending.
   *
   * Returns an unsubscribe function to stop listening to events.
   *
   * #### Example
   *
   * ```js
   * const unsubscribe = firebase.firestore().collection('users')
   *   .onSnapshot({
   *     error: (e) => console.error(e),
   *     next: (querySnapshot) => {},
   *   });
   *
   * unsubscribe();
   * ```
   *
   * @param observer A single object containing `next` and `error` callbacks.
   */
  onSnapshot(observer: { complete?: Function, error?: Function, next?: Function }): Function;

  /**
   * Attaches a listener for `QuerySnapshot` events with snapshot listener options.
   *
   * NOTE: Although an complete callback can be provided, it will never be called because the snapshot stream is never-ending.
   *
   * Returns an unsubscribe function to stop listening to events.
   *
   * #### Example
   *
   * ```js
   * const unsubscribe = firebase.firestore().collection('users')
   *   .onSnapshot({
   *     includeMetadataChanges: true,
   *   }, {
   *     error: (e) => console.error(e),
   *     next: (querySnapshot) => {},
   *   });
   *
   * unsubscribe();
   * ```
   *
   * @param options Options controlling the listen behavior.
   * @param observer A single object containing `next` and `error` callbacks.
   */
  onSnapshot(
    options: SnapshotListenOptions,
    observer: { complete?: Function, error?: Function, next?: Function },
  ): Function;

  /**
   * Attaches a listener for `QuerySnapshot` events.
   *
   * NOTE: Although an onCompletion callback can be provided, it will never be called because the snapshot stream is never-ending.
   *
   * Returns an unsubscribe function to stop listening to events.
   *
   * #### Example
   *
   * ```js
   * const unsubscribe = firebase.firestore().collection('users')
   *   .onSnapshot(
   *     (querySnapshot) => {}, // onNext
   *     (error) => console.error(error), // onError
   *   );
   *
   * unsubscribe();
   * ```
   * @param onNext A callback to be called every time a new `QuerySnapshot` is available.
   * @param onError A callback to be called if the listen fails or is cancelled. No further callbacks will occur.
   * @param onCompletion An optional function which will never be called.
   */
  onSnapshot(onNext: Function, onError?: Function, onCompletion?: Function): Function;

  /**
   * Attaches a listener for `QuerySnapshot` events with snapshot listener options.
   *
   * NOTE: Although an onCompletion callback can be provided, it will never be called because the snapshot stream is never-ending.
   *
   * Returns an unsubscribe function to stop listening to events.
   *
   * #### Example
   *
   * ```js
   * const unsubscribe = firebase.firestore().collection('users')
   *   .onSnapshot(
   *     { includeMetadataChanges: true }, // SnapshotListenerOptions
   *     (querySnapshot) => {}, // onNext
   *     (error) => console.error(error), // onError
   *   );
   *
   * unsubscribe();
   * ```
   * @param options Options controlling the listen behavior.
   * @param onNext A callback to be called every time a new `QuerySnapshot` is available.
   * @param onError A callback to be called if the listen fails or is cancelled. No further callbacks will occur.
   * @param onCompletion An optional function which will never be called.
   */
  onSnapshot(
    options: SnapshotListenOptions,
    onNext: Function,
    onError?: Function,
    onCompletion?: Function,
  ): Function;

  /**
   * Creates and returns a new Query that's additionally sorted by the specified field, optionally in descending order instead of ascending.
   *
   * * #### Example
   *
   * #### Example
   *
   * ```js
   * // Get users in order of age, descending
   * const querySnapshot = firebase.firestore()
   *   .collection('users')
   *   .orderBy('age', 'desc')
   *   .get();
   * ```
   *
   * @param fieldPath The field to sort by. Either a string or FieldPath instance.
   * @param directionStr Optional direction to sort by (`asc` or `desc`). If not specified, order will be ascending.
   */
  orderBy(fieldPath: string | FieldPath, directionStr?: 'asc' | 'desc'): Query;

  /**
   * Creates and returns a new Query that starts after the provided document (exclusive). The start
   * position is relative to the order of the query. The document must contain all of the fields
   * provided in the orderBy of this query.
   *
   * #### Example
   *
   * ```js
   * const user = await firebase.firestore().doc('users/alovelace').get();
   *
   * // Get all users up to, but not including, a specific user in order of age
   * const querySnapshot = await firebase.firestore()
   *   .collection('users')
   *   .orderBy('age')
   *   .startAfter(user);
   * ```
   *
   * > Cursor snapshot queries have limitations. Please see [Query limitations](/) for more information.
   *
   * @param snapshot The snapshot of the document to start after.
   */
  startAfter(snapshot: DocumentSnapshot): Query;

  /**
   * Creates and returns a new Query that starts after the provided fields relative to the order of
   * the query. The order of the field values must match the order of the order by clauses of the query.
   *
   * #### Example
   *
   * ```js
   * // Get all users who's age is above 30
   * const querySnapshot = await firebase.firestore()
   *   .collection('users')
   *   .orderBy('age')
   *   .startAfter(30);
   * ```
   *
   * @param fieldValues The field values to start this query after, in order of the query's order by.
   */
  startAfter(...fieldValues: any[]): Query;

  /**
   * Creates and returns a new Query that starts at the provided document (inclusive). The start
   * position is relative to the order of the query. The document must contain all of the
   * fields provided in the orderBy of this query.
   *
   * #### Example
   *
   * ```js
   * const user = await firebase.firestore().doc('users/alovelace').get();
   *
   * // Get all users up to a specific user in order of age
   * const querySnapshot = await firebase.firestore()
   *   .collection('users')
   *   .orderBy('age')
   *   .startAt(user);
   * ```
   *
   * > Cursor snapshot queries have limitations. Please see [Query limitations](/) for more information.
   *
   * @param snapshot The snapshot of the document to start at.
   */
  startAt(snapshot: DocumentSnapshot): Query;

  /**
   * Creates and returns a new Query that starts at the provided fields relative to the order of the query.
   * The order of the field values must match the order of the order by clauses of the query.
   *
   * #### Example
   *
   * ```js
   * // Get all users who's age is 30 or above
   * const querySnapshot = await firebase.firestore()
   *   .collection('users')
   *   .orderBy('age')
   *   .startAt(30);
   * ```
   *
   * @param fieldValues The field values to start this query at, in order of the query's order by.
   */
  startAt(...fieldValues: any[]): Query;
}

/**
 * A `QuerySnapshot` contains zero or more `DocumentSnapshot` objects representing the results of a query. The documents
 * can be accessed as an array via the `docs` property or enumerated using the `forEach` method. The number of documents
 * can be determined via the `empty` and `size` properties.
 */
export interface QuerySnapshot {
  /**
   * An array of all the documents in the `QuerySnapshot`.
   */
  docs: DocumentSnapshot[];

  /**
   * True if there are no documents in the `QuerySnapshot`.
   */
  empty: boolean;

  /**
   * Metadata about this snapshot, concerning its source and if it has local modifications.
   */
  metadata: SnapshotMetadata;

  /**
   * The query on which you called get or `onSnapshot` in order to `get` this `QuerySnapshot`.
   */
  query: Query;

  /**
   * The number of documents in the `QuerySnapshot`.
   */
  size: number;

  /**
   * Returns an array of the documents changes since the last snapshot. If this is the first snapshot, all documents
   * will be in the list as added changes.
   *
   * To include metadata changes, ensure that the `onSnapshot()` method includes metadata changes.
   *
   * #### Example
   *
   * ```js
   * firebase.firestore().collection('users')
   *   .onSnapshot((querySnapshot) => {
   *     console.log('Metadata Changes', querySnapshot.docChanges());
   *   });
   * ```
   *
   * #### Example - With metadata changes
   *
   * ```js
   * firebase.firestore().collection('users')
   *   .onSnapshot({ includeMetadataChanges: true }, (querySnapshot) => {
   *     console.log('Metadata Changes', querySnapshot.docChanges({
   *       includeMetadataChanges: true,
   *     }));
   *   });
   * ```
   *
   * @param options `SnapshotListenOptions` that control whether metadata-only changes (i.e. only `DocumentSnapshot.metadata` changed) should trigger snapshot events.
   */
  docChanges(options?: SnapshotListenOptions): DocumentChange[];

  /**
   * Enumerates all of the documents in the `QuerySnapshot`.
   *
   * #### Example
   *
   * ```js
   * const querySnapshot = await firebase.firestore().collection('users').get();
   *
   * querySnapshot.forEach((documentSnapshot) => {
   *   console.log('User', documentSnapshot.data());
   * })
   * ```
   *
   * @param callback A callback to be called with a `DocumentSnapshot` for each document in the snapshot.
   * @param thisArg The this binding for the callback.
   */
  forEach(callback: Function, thisArg?: any): void;

  /**
   * Returns true if this `QuerySnapshot` is equal to the provided one.
   *
   * #### Example
   *
   * ```js
   * const querySnapshot1 = await firebase.firestore().collection('users').limit(5).get();
   * const querySnapshot2 = await firebase.firestore().collection('users').limit(10).get();
   *
   * // false
   * querySnapshot1.isEqual(querySnapshot2);
   * ```
   *
   * > This operation can be resource intensive when dealing with large datasets.
   *
   * @param other The `QuerySnapshot` to compare against.
   */
  isEqual(other: QuerySnapshot): boolean;
}

/**
 * An options object that configures the behavior of set() calls in `DocumentReference`, `WriteBatch` and `Transaction`.
 * These calls can be configured to perform granular merges instead of overwriting the target documents in their entirety
 * by providing a `SetOptions` with `merge: true`.
 *
 * Using both `merge` and `mergeFields` together will throw an error.
 */
export interface SetOptions {
  /**
   * Changes the behavior of a `set()` call to only replace the values specified in its data argument.
   * Fields omitted from the `set()` call remain untouched.
   */
  merge: boolean;

  /**
   * Changes the behavior of `set()` calls to only replace the specified field paths.
   * Any field path that is not specified is ignored and remains untouched.
   */
  mergeField: (string | FieldPath)[];
}

/**
 * Specifies custom configurations for your Cloud Firestore instance. You must set these before invoking any other methods.
 *
 * Used with `firebase.firestore().settings()`.
 */
export interface Settings {
  /**
   * Enables or disables local persistent storage.
   */
  persistence: boolean;

  /**
   * An approximate cache size threshold for the on-disk data. If the cache grows beyond this size, Firestore will start
   * removing data that hasn't been recently used. The size is not a guarantee that the cache will stay below that size,
   * only that if the cache exceeds the given size, cleanup will be attempted.
   *
   * To disable garbage collection and set an unlimited cache size, use `firebase.firestore.CACHE_SIZE_UNLIMITED`.
   */
  cacheSizeBytes: number;

  /**
   * The hostname to connect to.
   */
  host: string;

  /**
   * Whether to use SSL when connecting.
   */
  ssl: boolean;
}

/**
 * An options object that can be passed to `DocumentReference.onSnapshot()`, `Query.onSnapshot()` and `QuerySnapshot.docChanges()`
 * to control which types of changes to include in the result set.
 */
export interface SnapshotListenOptions {
  /**
   * Include a change even if only the metadata of the query or of a document changed. Default is false.
   */
  includeMetadataChanges: boolean;
}

/**
 * Metadata about a snapshot, describing the state of the snapshot.
 */
export interface SnapshotMetadata {
  /**
   * True if the snapshot includes local writes (`set()` or `update()` calls) that haven't been committed to the backend yet.
   * If your listener has opted into metadata updates (via `SnapshotListenOptions`) you will receive another snapshot with
   * `fromCache` equal to false once the client has received up-to-date data from the backend.
   */
  fromCache: boolean;

  /**
   * True if the snapshot contains the result of local writes (e.g. `set()` or `update()` calls) that have not yet been
   * committed to the backend. If your listener has opted into metadata updates (via `SnapshotListenOptions`) you will
   * receive another snapshot with `hasPendingWrites` equal to false once the writes have been committed to the backend.
   */
  hasPendingWrites: boolean;

  /**
   * Returns true if this `SnapshotMetadata` is equal to the provided one.
   *
   * @param other The `SnapshotMetadata` to compare against.
   */
  isEqual(other: SnapshotMetadata): boolean;
}

/**
 * A Timestamp represents a point in time independent of any time zone or calendar, represented as seconds and
 * fractions of seconds at nanosecond resolution in UTC Epoch time.
 *
 * It is encoded using the Proleptic Gregorian Calendar which extends the Gregorian calendar backwards to year one.
 * It is encoded assuming all minutes are 60 seconds long, i.e. leap seconds are "smeared" so that no leap second table
 * is needed for interpretation. Range is from 0001-01-01T00:00:00Z to 9999-12-31T23:59:59.999999999Z.
 */
export class Timestamp {
  /**
   * Creates a new timestamp from the given JavaScript [Date](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Date).
   *
   * @param date The date to initialize the `Timestamp` from.
   */
  static fromDate: (date: Date) => Timestamp;

  /**
   * Creates a new timestamp from the given number of milliseconds.
   *
   * @param milliseconds Number of milliseconds since Unix epoch 1970-01-01T00:00:00Z.
   */
  static fromMillis: (milliseconds: number) => Timestamp;

  /**
   * Creates a new timestamp with the current date, with millisecond precision.
   */
  static now: () => Timestamp;

  /**
   * Creates a new timestamp.
   *
   * @param seconds The number of seconds of UTC time since Unix epoch 1970-01-01T00:00:00Z. Must be from 0001-01-01T00:00:00Z to 9999-12-31T23:59:59Z inclusive.
   * @param nanoseconds The non-negative fractions of a second at nanosecond resolution. Negative second values with fractions must still have non-negative nanoseconds values that count forward in time. Must be from 0 to 999,999,999 inclusive.
   */
  // TODO don't think this is possible on flow?
  // constructor(seconds: number, nanoseconds: number);

  /**
   * The number of nanoseconds of this `Timestamp`;
   */
  nanoseconds: number;

  /**
   * The number of seconds of this `Timestamp`.
   */
  seconds: number;

  /**
   * Returns true if this `Timestamp` is equal to the provided one.
   *
   * @param other The `Timestamp` to compare against.
   */
  isEqual: (other: Timestamp) => boolean;

  /**
   * Convert a Timestamp to a JavaScript Date object. This conversion causes a loss of precision since Date objects
   * only support millisecond precision.
   *
   * Returns a JavaScript [Date](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Date) with
   * millseconds precision.
   */
  toDate: () => Date;

  /**
   * Convert a timestamp to a numeric timestamp (in milliseconds since epoch). This operation causes a loss of precision.
   *
   * The point in time corresponding to this timestamp, represented as the number of milliseconds since Unix epoch 1970-01-01T00:00:00Z.
   */
  toMillis: () => number;
}

/**
 * A reference to a transaction. The `Transaction` object passed to a transaction's updateFunction provides the methods to
 * read and write data within the transaction context. See `Firestore.runTransaction()`.
 *
 * A transaction consists of any number of `get()` operations followed by any number of write operations such as set(),
 * `update()`, or `delete()`. In the case of a concurrent edit, Cloud Firestore runs the entire transaction again. For example,
 * if a transaction reads documents and another client modifies any of those documents, Cloud Firestore retries the transaction.
 * This feature ensures that the transaction runs on up-to-date and consistent data.
 *
 * Transactions never partially apply writes. All writes execute at the end of a successful transaction.
 *
 * When using transactions, note that:
 *   - Read operations must come before write operations.
 *   - A function calling a transaction (transaction function) might run more than once if a concurrent edit affects a document that the transaction reads.
 *   - Transaction functions should not directly modify application state (return a value from the `updateFunction`).
 *   - Transactions will fail when the client is offline.
 */
export interface Transaction {
  /**
   * Deletes the document referred to by the provided `DocumentReference`.
   *
   * #### Example
   *
   * ```js
   * const docRef = firebase.firestore().doc('users/alovelace');
   *
   * await firebase.firestore().runTransaction((transaction) => {
   *   return transaction.delete(docRef);
   * });
   * ```
   *
   * @param documentRef A reference to the document to be deleted.
   */
  delete(documentRef: DocumentReference): Transaction;

  /**
   * Reads the document referenced by the provided `DocumentReference`.
   *
   * #### Example
   *
   * ```js
   * const docRef = firebase.firestore().doc('users/alovelace');
   *
   * await firebase.firestore().runTransaction(async (transaction) => {
   *   const snapshot = await transaction.get(docRef);
   *    // use snapshot with transaction (see set() or update())
   *    ...
   * });
   * ```
   *
   * @param documentRef A reference to the document to be read.
   */
  get(documentRef: DocumentReference): Promise<DocumentSnapshot>;

  /**
   * Writes to the document referred to by the provided `DocumentReference`. If the document does not exist yet,
   * it will be created. If you pass `SetOptions`, the provided data can be merged into the existing document.
   *
   * #### Example
   *
   * ```js
   * const docRef = firebase.firestore().doc('users/alovelace');
   *
   * await firebase.firestore().runTransaction((transaction) => {
   *   const snapshot = await transaction.get(docRef);
   *   const snapshotData = snapshot.data();
   *
   *   return transaction.set(docRef, {
   *     ...data,
   *     age: 30, // new field
   *   });
   * });
   * ```
   *
   * @param documentRef A reference to the document to be set.
   * @param data An object of the fields and values for the document.
   * @param options An object to configure the set behavior.
   */
  set(documentRef: DocumentReference, data: { [key]: value }, options?: SetOptions): Transaction;

  /**
   * Updates fields in the document referred to by the provided `DocumentReference`. The update will fail if applied
   * to a document that does not exist.
   *
   * #### Example
   *
   * ```js
   * const docRef = firebase.firestore().doc('users/alovelace');
   *
   * await firebase.firestore().runTransaction((transaction) => {
   *   const snapshot = await transaction.get(docRef);
   *
   *   return transaction.update(docRef, {
   *     age: snapshot.data().age + 1,
   *   });
   * });
   * ```
   *
   * @param documentRef A reference to the document to be updated.
   * @param data An object containing the fields and values with which to update the document. Fields can contain dots to reference nested fields within the document.
   */
  update(documentRef: DocumentReference, data: { [key]: value }): Transaction;

  /**
   * Updates fields in the document referred to by the provided DocumentReference. The update will fail if applied to
   * a document that does not exist.
   *
   * Nested fields can be updated by providing dot-separated field path strings or by providing FieldPath objects.
   *
   * #### Example
   *
   * ```js
   * const docRef = firebase.firestore().doc('users/alovelace');
   *
   * await firebase.firestore().runTransaction((transaction) => {
   *   const snapshot = await transaction.get(docRef);
   *
   *   return transaction.update(docRef, 'age', snapshot.data().age + 1);
   * });
   * ```
   *
   * @param documentRef A reference to the document to be updated.
   * @param field The first field to update.
   * @param value The first value.
   * @param moreFieldsAndValues Additional key/value pairs.
   */
  update(
    documentRef: DocumentReference,
    field: string | FieldPath,
    value: any,
    ...moreFieldsAndValues: any[]
  ): Transaction;
}

/**
 * A write batch, used to perform multiple writes as a single atomic unit.
 *
 * A WriteBatch object can be acquired by calling `firestore.batch()`. It provides methods for adding
 * writes to the write batch. None of the writes will be committed (or visible locally) until
 * `WriteBatch.commit()` is called.
 *
 * Unlike transactions, write batches are persisted offline and therefore are preferable when you don't need to
 * condition your writes on read data.
 */
export interface WriteBatch {
  /**
   * Commits all of the writes in this write batch as a single atomic unit.
   *
   * Returns a Promise resolved once all of the writes in the batch have been successfully written
   * to the backend as an atomic unit. Note that it won't resolve while you're offline.
   *
   * #### Example
   *
   * ```js
   * const batch = firebase.firestore().batch();
   *
   * // Perform batch operations...
   *
   * await batch.commit();
   * ```
   */
  commit(): Promise<void>;

  /**
   * Deletes the document referred to by the provided `DocumentReference`.
   *
   * #### Example
   *
   * ```js
   * const batch = firebase.firestore().batch();
   * const docRef = firebase.firestore().doc('users/alovelace');
   *
   * batch.delete(docRef);
   * ```
   *
   * @param documentRef A reference to the document to be deleted.
   */
  delete(documentRef: DocumentReference): WriteBatch;

  /**
   * Writes to the document referred to by the provided DocumentReference. If the document does
   * not exist yet, it will be created. If you pass SetOptions, the provided data can be merged
   * into the existing document.
   *
   * #### Example
   *
   * ```js
   * const batch = firebase.firestore().batch();
   * const docRef = firebase.firestore().doc('users/dsmith');
   *
   * batch.set(docRef, {
   *   name: 'David Smith',
   *   age: 25,
   * });
   * ```
   *
   * @param documentRef A reference to the document to be set.
   * @param data An object of the fields and values for the document.
   * @param options An object to configure the set behavior.
   */
  set(documentRef: DocumentReference, data: { [key]: value }, options?: SetOptions): WriteBatch;

  /**
   * Updates fields in the document referred to by the provided DocumentReference. The update will fail if applied to a document that does not exist.
   *
   * #### Example
   *
   * ```js
   * const batch = firebase.firestore().batch();
   * const docRef = firebase.firestore().doc('users/alovelace');
   *
   * batch.update(docRef, {
   *   city: 'SF',
   * });
   * ```
   *
   * @param documentRef A reference to the document to be updated.
   * @param data An object containing the fields and values with which to update the document. Fields can contain dots to reference nested fields within the document.
   */
  update(documentRef: DocumentReference, data: { [key]: value }): WriteBatch;

  /**
   * Updates fields in the document referred to by this DocumentReference. The update will fail if applied to a document that does not exist.
   *
   * Nested fields can be update by providing dot-separated field path strings or by providing FieldPath objects.
   *
   * #### Example
   *
   * ```js
   * const batch = firebase.firestore().batch();
   * const docRef = firebase.firestore().doc('users/alovelace');
   *
   * batch.update(docRef, 'city', 'SF', 'age', 31);
   * ```
   *
   * @param documentRef A reference to the document to be updated.
   * @param field The first field to update.
   * @param value The first value.
   * @param moreFieldAndValues Additional key value pairs.
   */
  update(
    documentRef: DocumentReference,
    field: string | FieldPath,
    value: any,
    ...moreFieldAndValues: any[]
  ): WriteBatch;
}

export interface Statics {
  /**
   * Returns the `Blob` class.
   */
  Blob: Blob;

  /**
   * Returns the `FieldPath` class.
   */
  FieldPath: FieldPath;

  /**
   * Returns the `FieldValue` class.
   */
  FieldValue: FieldValue;

  /**
   * Returns the `GeoPoint` class.
   */
  GeoPoint: GeoPoint;

  /**
   * Returns the `Timestamp` class.
   */
  Timestamp: Timestamp;

  /**
   * Used to set the cache size to unlimited when passing to `cacheSizeBytes` in
   * `firebase.firestore().settings()`.
   */
  CACHE_SIZE_UNLIMITED: number;

  /**
   * Sets the verbosity of Cloud Firestore native device logs (debug, error, or silent).
   *
   * - `debug`: the most verbose logging level, primarily for debugging.
   * - `error`: logs only error events.
   * - `silent`: turn off logging.
   *
   * #### Example
   *
   * ```js
   * firebase.firestore.setLogLevel('silent');
   * ```
   *
   * @param logLevel The verbosity you set for activity and error logging.
   */
  setLogLevel(logLevel: 'debug' | 'error' | 'silent'): void;
}

/**
 * The Firebase Cloud Firestore service is available for the default app or a given app.
 *
 * #### Example 1
 *
 * Get the firestore instance for the **default app**:
 *
 * ```js
 * const firestoreForDefaultApp = firebase.firestore();
 * ```
 *
 * #### Example 2
 *
 * Get the firestore instance for a **secondary app**:
 *
 * ```js
 * const otherApp = firebase.app('otherApp');
 * const firestoreForOtherApp = firebase.firestore(otherApp);
 * ```
 *
 */
export interface Module extends ReactNativeFirebaseModule {
  /**
   * Creates a write batch, used for performing multiple writes as a single atomic operation.
   * The maximum number of writes allowed in a single WriteBatch is 500, but note that each usage
   * of `FieldValue.serverTimestamp()`, `FieldValue.arrayUnion()`, `FieldValue.arrayRemove()`, or `FieldValue.increment()`
   * inside a WriteBatch counts as an additional write.
   *
   * #### Example
   *
   * ```js
   * const batch = firebase.firestore().batch();
   * batch.delete(...);
   * ```
   */
  batch(): WriteBatch;

  /**
   * Gets a `CollectionReference` instance that refers to the collection at the specified path.
   *
   * #### Example
   *
   * ```js
   * const collectionReference = firebase.firestore().collection('users');
   * ```
   *
   * @param collectionPath A slash-separated path to a collection.
   */
  collection(collectionPath: string): CollectionReference;

  /**
   * Creates and returns a new Query that includes all documents in the database that are contained
   * in a collection or subcollection with the given collectionId.
   *
   * #### Example
   *
   * ```js
   * const collectionGroup = firebase.firestore().collection('orders');
   * ```
   *
   * @param collectionId Identifies the collections to query over. Every collection or subcollection with this ID as the last segment of its path will be included. Cannot contain a slash.
   */
  collectionGroup(collectionId: string): Query;

  /**
   * Disables network usage for this instance. It can be re-enabled via `enableNetwork()`. While the
   * network is disabled, any snapshot listeners or get() calls will return results from cache, and any
   * write operations will be queued until the network is restored.
   *
   * Returns a promise that is resolved once the network has been disabled.
   *
   * #### Example
   *
   * ```js
   * await firebase.firestore().disableNetwork();
   * ```
   */
  disableNetwork(): Promise<void>;

  /**
   * Gets a `DocumentReference` instance that refers to the document at the specified path.
   *
   * #### Example
   *
   * ```js
   * const documentReference = firebase.firestore().doc('users/alovelace');
   * ```
   *
   * @param documentPath A slash-separated path to a document.
   */
  doc(documentPath: string): DocumentReference;

  /**
   * Re-enables use of the network for this Firestore instance after a prior call to `disableNetwork()`.
   */
  enableNetwork(): Promise<void>;

  /**
   * Executes the given `updateFunction` and then attempts to commit the changes applied within the transaction.
   * If any document read within the transaction has changed, Cloud Firestore retries the `updateFunction`.
   * If it fails to commit after 5 attempts, the transaction fails.
   *
   * The maximum number of writes allowed in a single transaction is 500, but note that each usage of
   * `FieldValue.serverTimestamp()`, `FieldValue.arrayUnion()`, `FieldValue.arrayRemove()`, or `FieldValue.increment()`
   * inside a transaction counts as an additional write.
   *
   * #### Example
   *
   * ```js
   * const cityRef = firebase.firestore().doc('cities/SF');
   *
   * await firebase.firestore()
   *   .runTransaction(async (transaction) => {
   *     const snapshot = await transaction.get(cityRef);
   *     await transaction.update(cityRef, {
   *       population: snapshot.data().population + 1,
   *     });
   *   });
   * ```
   */
  runTransaction(updateFunction: (transaction: Transaction) => Promise): Promise<any>;

  /**
   * Specifies custom settings to be used to configure the Firestore instance. Must be set before invoking any other methods.
   *
   * #### Example
   *
   * ```js
   * const settings = {
   *   cacheSizeBytes: firebase.firestore.CACHE_SIZE_UNLIMITED,
   * };
   *
   * await firebase.firestore().settings(settings);
   * ```
   *
   * @param settings A `Settings` object.
   */
  settings(settings: Settings): Promise<void>;
}

declare module '@react-native-firebase/firestore' {
  import type {
    ReactNativeFirebaseNamespace,
    ReactNativeFirebaseModuleAndStatics,
  } from '@react-native-firebase/app-types/index.js.flow';
  /**
   * @example
   * ```js
   * import { firebase } from '@react-native-firebase/firestore';
   * firebase.firestore().X(...);
   * ```
   */
  declare export var firebase: {} & ReactNativeFirebaseNamespace;

  /**
   * @example
   * ```js
   * import firestore from '@react-native-firebase/firestore';
   * firestore().X(...);
   * ```
   */
  declare export default ReactNativeFirebaseModuleAndStatics<Module, Statics>;
}

/**
 * Attach namespace to `firebase.` and `FirebaseApp.`.
 */
declare module '@react-native-firebase/app-types' {
  import type { ReactNativeFirebaseModuleAndStatics } from '@react-native-firebase/app-types/index.js.flow';

  declare interface ReactNativeFirebaseNamespace {
    /**
     * Firestore
     */
    firestore: ReactNativeFirebaseModuleAndStatics<Module, Statics>;
  }

  declare interface FirebaseApp {
    /**
     * Firestore
     */
    firestore(): Module;
  }
}