messaging-api.ts

/*!
 * @license
 * Copyright 2021 Google Inc.
 *
 * 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 { FirebaseArrayIndexError, FirebaseError } from '../app/index';

export interface BaseMessage {
  data?: { [key: string]: string };
  notification?: Notification;
  android?: AndroidConfig;
  webpush?: WebpushConfig;
  apns?: ApnsConfig;
  fcmOptions?: FcmOptions;
}

export interface TokenMessage extends BaseMessage {
  token: string;
}

export interface TopicMessage extends BaseMessage {
  topic: string;
}

export interface ConditionMessage extends BaseMessage {
  condition: string;
}

/**
 * Payload for the {@link Messaging.send} operation. The payload contains all the fields
 * in the BaseMessage type, and exactly one of token, topic or condition.
 */
export type Message = TokenMessage | TopicMessage | ConditionMessage;

/**
 * Payload for the {@link Messaging.sendEachForMulticast} method. The payload contains all the fields
 * in the BaseMessage type, and a list of tokens.
 */
export interface MulticastMessage extends BaseMessage {
  tokens: string[];
}

/**
   * A notification that can be included in {@link Message}.
   */
export interface Notification {
  /**
   * The title of the notification.
   */
  title?: string;
  /**
   * The notification body
   */
  body?: string;
  /**
   * URL of an image to be displayed in the notification.
   */
  imageUrl?: string;
}

/**
 * Represents platform-independent options for features provided by the FCM SDKs.
 */
export interface FcmOptions {
  /**
   * The label associated with the message's analytics data.
   */
  analyticsLabel?: string;
}

/**
 * Represents the WebPush protocol options that can be included in an
 * {@link Message}.
 */
export interface WebpushConfig {

  /**
   * A collection of WebPush headers. Header values must be strings.
   *
   * See {@link https://tools.ietf.org/html/rfc8030#section-5 | WebPush specification}
   * for supported headers.
   */
  headers?: { [key: string]: string };

  /**
   * A collection of data fields.
   */
  data?: { [key: string]: string };

  /**
   * A WebPush notification payload to be included in the message.
   */
  notification?: WebpushNotification;

  /**
   * Options for features provided by the FCM SDK for Web.
   */
  fcmOptions?: WebpushFcmOptions;
}

/** Represents options for features provided by the FCM SDK for Web
 * (which are not part of the Webpush standard).
 */
export interface WebpushFcmOptions {

  /**
   * The link to open when the user clicks on the notification.
   * For all URL values, HTTPS is required.
   */
  link?: string;
}

/**
 * Represents the WebPush-specific notification options that can be included in
 * {@link WebpushConfig}. This supports most of the standard
 * options as defined in the Web Notification
 * {@link https://developer.mozilla.org/en-US/docs/Web/API/notification/Notification | specification}.
 */
export interface WebpushNotification {

  /**
   * Title text of the notification.
   */
  title?: string;

  /**
   * An array of notification actions representing the actions
   * available to the user when the notification is presented.
   */
  actions?: Array<{

    /**
     * An action available to the user when the notification is presented
     */
    action: string;

    /**
     * Optional icon for a notification action.
     */
    icon?: string;

    /**
     * Title of the notification action.
     */
    title: string;
  }>;

  /**
   * URL of the image used to represent the notification when there is
   * not enough space to display the notification itself.
   */
  badge?: string;

  /**
   * Body text of the notification.
   */
  body?: string;

  /**
   * Arbitrary data that you want associated with the notification.
   * This can be of any data type.
   */
  data?: any;

  /**
   * The direction in which to display the notification. Must be one
   * of `auto`, `ltr` or `rtl`.
   */
  dir?: 'auto' | 'ltr' | 'rtl';

  /**
   * URL to the notification icon.
   */
  icon?: string;

  /**
   * URL of an image to be displayed in the notification.
   */
  image?: string;

  /**
   * The notification's language as a BCP 47 language tag.
   */
  lang?: string;

  /**
   * A boolean specifying whether the user should be notified after a
   * new notification replaces an old one. Defaults to false.
   */
  renotify?: boolean;

  /**
   * Indicates that a notification should remain active until the user
   * clicks or dismisses it, rather than closing automatically.
   * Defaults to false.
   */
  requireInteraction?: boolean;

  /**
   * A boolean specifying whether the notification should be silent.
   * Defaults to false.
   */
  silent?: boolean;

  /**
   * An identifying tag for the notification.
   */
  tag?: string;

  /**
   * Timestamp of the notification. Refer to
   * https://developer.mozilla.org/en-US/docs/Web/API/notification/timestamp
   * for details.
   */
  timestamp?: number;

  /**
   * A vibration pattern for the device's vibration hardware to emit
   * when the notification fires.
   */
  vibrate?: number | number[];
  [key: string]: any;
}

/**
 * Represents the APNs-specific options that can be included in an
 * {@link Message}. Refer to
 * {@link https://developer.apple.com/library/content/documentation/NetworkingInternet/Conceptual/RemoteNotificationsPG/CommunicatingwithAPNs.html |
 * Apple documentation} for various headers and payload fields supported by APNs.
 */
export interface ApnsConfig {
  /**
   * APN `live_activity_push_to_start_token` or `live_activity_push_token` to start or update live activities.
   */
  live_activity_token?: string;
  /**
   * A collection of APNs headers. Header values must be strings.
   */
  headers?: { [key: string]: string };

  /**
   * An APNs payload to be included in the message.
   */
  payload?: ApnsPayload;

  /**
   * Options for features provided by the FCM SDK for iOS.
   */
  fcmOptions?: ApnsFcmOptions;
}

/**
 * Represents the payload of an APNs message. Mainly consists of the `aps`
 * dictionary. But may also contain other arbitrary custom keys.
 */
export interface ApnsPayload {

  /**
   * The `aps` dictionary to be included in the message.
   */
  aps: Aps;
  [customData: string]: any;
}

/**
 * Represents the {@link https://developer.apple.com/library/content/documentation/NetworkingInternet/Conceptual/RemoteNotificationsPG/PayloadKeyReference.html |
 * aps dictionary} that is part of APNs messages.
 */
export interface Aps {

  /**
   * Alert to be included in the message. This may be a string or an object of
   * type `admin.messaging.ApsAlert`.
   */
  alert?: string | ApsAlert;

  /**
   * Badge to be displayed with the message. Set to 0 to remove the badge. When
   * not specified, the badge will remain unchanged.
   */
  badge?: number;

  /**
   * Sound to be played with the message.
   */
  sound?: string | CriticalSound;

  /**
   * Specifies whether to configure a background update notification.
   */
  contentAvailable?: boolean;

  /**
   * Specifies whether to set the `mutable-content` property on the message
   * so the clients can modify the notification via app extensions.
   */
  mutableContent?: boolean;

  /**
   * Type of the notification.
   */
  category?: string;

  /**
   * An app-specific identifier for grouping notifications.
   */
  threadId?: string;
  [customData: string]: any;
}

export interface ApsAlert {
  title?: string;
  subtitle?: string;
  body?: string;
  locKey?: string;
  locArgs?: string[];
  titleLocKey?: string;
  titleLocArgs?: string[];
  subtitleLocKey?: string;
  subtitleLocArgs?: string[];
  actionLocKey?: string;
  launchImage?: string;
}

/**
 * Represents a critical sound configuration that can be included in the
 * `aps` dictionary of an APNs payload.
 */
export interface CriticalSound {

  /**
   * The critical alert flag. Set to `true` to enable the critical alert.
   */
  critical?: boolean;

  /**
   * The name of a sound file in the app's main bundle or in the `Library/Sounds`
   * folder of the app's container directory. Specify the string "default" to play
   * the system sound.
   */
  name: string;

  /**
   * The volume for the critical alert's sound. Must be a value between 0.0
   * (silent) and 1.0 (full volume).
   */
  volume?: number;
}

/**
 * Represents options for features provided by the FCM SDK for iOS.
 */
export interface ApnsFcmOptions {

  /**
   * The label associated with the message's analytics data.
   */
  analyticsLabel?: string;

  /**
   * URL of an image to be displayed in the notification.
   */
  imageUrl?: string;
}


/**
 * Represents the Android-specific options that can be included in an
 * {@link Message}.
 */
export interface AndroidConfig {

  /**
   * Collapse key for the message. Collapse key serves as an identifier for a
   * group of messages that can be collapsed, so that only the last message gets
   * sent when delivery can be resumed. A maximum of four different collapse keys
   * may be active at any given time.
   */
  collapseKey?: string;

  /**
   * Priority of the message. Must be either `normal` or `high`.
   */
  priority?: ('high' | 'normal');

  /**
   * Time-to-live duration of the message in milliseconds.
   */
  ttl?: number;

  /**
   * Package name of the application where the registration tokens must match
   * in order to receive the message.
   */
  restrictedPackageName?: string;

  /**
   * A collection of data fields to be included in the message. All values must
   * be strings. When provided, overrides any data fields set on the top-level
   * {@link Message}.
   */
  data?: { [key: string]: string };

  /**
   * Android notification to be included in the message.
   */
  notification?: AndroidNotification;

  /**
   * Options for features provided by the FCM SDK for Android.
   */
  fcmOptions?: AndroidFcmOptions;

  /**
  * A boolean indicating whether messages will be allowed to be delivered to
  * the app while the device is in direct boot mode.
  */
  directBootOk?: boolean;
}

/**
  * Represents the Android-specific notification options that can be included in
  * {@link AndroidConfig}.
  */
export interface AndroidNotification {
  /**
   * Title of the Android notification. When provided, overrides the title set via
   * `admin.messaging.Notification`.
   */
  title?: string;

  /**
   * Body of the Android notification. When provided, overrides the body set via
   * `admin.messaging.Notification`.
   */
  body?: string;

  /**
   * Icon resource for the Android notification.
   */
  icon?: string;

  /**
   * Notification icon color in `#rrggbb` format.
   */
  color?: string;

  /**
   * File name of the sound to be played when the device receives the
   * notification.
   */
  sound?: string;

  /**
   * Notification tag. This is an identifier used to replace existing
   * notifications in the notification drawer. If not specified, each request
   * creates a new notification.
   */
  tag?: string;

  /**
   * URL of an image to be displayed in the notification.
   */
  imageUrl?: string;

  /**
   * Action associated with a user click on the notification. If specified, an
   * activity with a matching Intent Filter is launched when a user clicks on the
   * notification.
   */
  clickAction?: string;

  /**
   * Key of the body string in the app's string resource to use to localize the
   * body text.
   *
   */
  bodyLocKey?: string;

  /**
   * An array of resource keys that will be used in place of the format
   * specifiers in `bodyLocKey`.
   */
  bodyLocArgs?: string[];

  /**
   * Key of the title string in the app's string resource to use to localize the
   * title text.
   */
  titleLocKey?: string;

  /**
   * An array of resource keys that will be used in place of the format
   * specifiers in `titleLocKey`.
   */
  titleLocArgs?: string[];

  /**
   * The Android notification channel ID (new in Android O). The app must create
   * a channel with this channel ID before any notification with this channel ID
   * can be received. If you don't send this channel ID in the request, or if the
   * channel ID provided has not yet been created by the app, FCM uses the channel
   * ID specified in the app manifest.
   */
  channelId?: string;

  /**
   * Sets the "ticker" text, which is sent to accessibility services. Prior to
   * API level 21 (Lollipop), sets the text that is displayed in the status bar
   * when the notification first arrives.
   */
  ticker?: string;

  /**
   * When set to `false` or unset, the notification is automatically dismissed when
   * the user clicks it in the panel. When set to `true`, the notification persists
   * even when the user clicks it.
   */
  sticky?: boolean;

  /**
   * For notifications that inform users about events with an absolute time reference, sets
   * the time that the event in the notification occurred. Notifications
   * in the panel are sorted by this time.
   */
  eventTimestamp?: Date;

  /**
   * Sets whether or not this notification is relevant only to the current device.
   * Some notifications can be bridged to other devices for remote display, such as
   * a Wear OS watch. This hint can be set to recommend this notification not be bridged.
   * See {@link https://developer.android.com/training/wearables/notifications/bridger#existing-method-of-preventing-bridging |
   * Wear OS guides}.
   */
  localOnly?: boolean;

  /**
   * Sets the relative priority for this notification. Low-priority notifications
   * may be hidden from the user in certain situations. Note this priority differs
   * from `AndroidMessagePriority`. This priority is processed by the client after
   * the message has been delivered. Whereas `AndroidMessagePriority` is an FCM concept
   * that controls when the message is delivered.
   */
  priority?: ('min' | 'low' | 'default' | 'high' | 'max');

  /**
   * Sets the vibration pattern to use. Pass in an array of milliseconds to
   * turn the vibrator on or off. The first value indicates the duration to wait before
   * turning the vibrator on. The next value indicates the duration to keep the
   * vibrator on. Subsequent values alternate between duration to turn the vibrator
   * off and to turn the vibrator on. If `vibrateTimingsMillis` is set and `defaultVibrateTimings`
   * is set to `true`, the default value is used instead of the user-specified `vibrateTimingsMillis`.
   */
  vibrateTimingsMillis?: number[];

  /**
   * If set to `true`, use the Android framework's default vibrate pattern for the
   * notification. Default values are specified in {@link https://android.googlesource.com/platform/frameworks/base/+/master/core/res/res/values/config.xml |
   * config.xml}. If `defaultVibrateTimings` is set to `true` and `vibrateTimingsMillis` is also set,
   * the default value is used instead of the user-specified `vibrateTimingsMillis`.
   */
  defaultVibrateTimings?: boolean;

  /**
   * If set to `true`, use the Android framework's default sound for the notification.
   * Default values are specified in {@link https://android.googlesource.com/platform/frameworks/base/+/master/core/res/res/values/config.xml |
   * config.xml}.
   */
  defaultSound?: boolean;

  /**
   * Settings to control the notification's LED blinking rate and color if LED is
   * available on the device. The total blinking time is controlled by the OS.
   */
  lightSettings?: LightSettings;

  /**
   * If set to `true`, use the Android framework's default LED light settings
   * for the notification. Default values are specified in {@link https://android.googlesource.com/platform/frameworks/base/+/master/core/res/res/values/config.xml |
   * config.xml}.
   * If `default_light_settings` is set to `true` and `light_settings` is also set,
   * the user-specified `light_settings` is used instead of the default value.
   */
  defaultLightSettings?: boolean;

  /**
   * Sets the visibility of the notification. Must be either `private`, `public`,
   * or `secret`. If unspecified, it remains undefined in the Admin SDK, and
   * defers to the FCM backend's default mapping.
   */
  visibility?: ('private' | 'public' | 'secret');

  /**
   * Sets the number of items this notification represents. May be displayed as a
   * badge count for Launchers that support badging. See {@link https://developer.android.com/training/notify-user/badges |
   * NotificationBadge}.
   * For example, this might be useful if you're using just one notification to
   * represent multiple new messages but you want the count here to represent
   * the number of total new messages. If zero or unspecified, systems
   * that support badging use the default, which is to increment a number
   * displayed on the long-press menu each time a new notification arrives.
   */
  notificationCount?: number;

  /**
   * Sets if this notification should attempt to be proxied. Must be either
   * `allow`, `deny` or `if_priority_lowered`. If unspecified, it remains
   * undefined in the Admin SDK, and defers to the FCM backend's default mapping.
   */
  proxy?: ('allow' | 'deny' | 'if_priority_lowered');
}

/**
  * Represents settings to control notification LED that can be included in
  * {@link AndroidNotification}.
  */
export interface LightSettings {
  /**
   * Required. Sets color of the LED in `#rrggbb` or `#rrggbbaa` format.
   */
  color: string;

  /**
   * Required. Along with `light_off_duration`, defines the blink rate of LED flashes.
   */
  lightOnDurationMillis: number;

  /**
   * Required. Along with `light_on_duration`, defines the blink rate of LED flashes.
   */
  lightOffDurationMillis: number;
}

/**
  * Represents options for features provided by the FCM SDK for Android.
  */
export interface AndroidFcmOptions {

  /**
   * The label associated with the message's analytics data.
   */
  analyticsLabel?: string;
}

/**
 * Interface representing an FCM legacy API data message payload. Data
 * messages let developers send up to 4KB of custom key-value pairs. The
 * keys and values must both be strings. Keys can be any custom string,
 * except for the following reserved strings:
 *
 * <ul>
 *   <li><code>from</code></li>
 *   <li>Anything starting with <code>google.</code></li>
 * </ul>
 *
 * See {@link https://firebase.google.com/docs/cloud-messaging/send-message | Build send requests}
 * for code samples and detailed documentation.
 */
export interface DataMessagePayload {
  [key: string]: string;
}

/**
 * Interface representing an FCM legacy API notification message payload.
 * Notification messages let developers send up to 4KB of predefined
 * key-value pairs. Accepted keys are outlined below.
 *
 * See {@link https://firebase.google.com/docs/cloud-messaging/send-message | Build send requests}
 * for code samples and detailed documentation.
 */
export interface NotificationMessagePayload {

  /**
   * Identifier used to replace existing notifications in the notification drawer.
   *
   * If not specified, each request creates a new notification.
   *
   * If specified and a notification with the same tag is already being shown,
   * the new notification replaces the existing one in the notification drawer.
   *
   * **Platforms:** Android
   */
  tag?: string;

  /**
   * The notification's body text.
   *
   * **Platforms:** iOS, Android, Web
   */
  body?: string;

  /**
   * The notification's icon.
   *
   * **Android:** Sets the notification icon to `myicon` for drawable resource
   * `myicon`. If you don't send this key in the request, FCM displays the
   * launcher icon specified in your app manifest.
   *
   * **Web:** The URL to use for the notification's icon.
   *
   * **Platforms:** Android, Web
   */
  icon?: string;

  /**
   * The value of the badge on the home screen app icon.
   *
   * If not specified, the badge is not changed.
   *
   * If set to `0`, the badge is removed.
   *
   * **Platforms:** iOS
   */
  badge?: string;

  /**
   * The notification icon's color, expressed in `#rrggbb` format.
   *
   * **Platforms:** Android
   */
  color?: string;

  /**
   * The sound to be played when the device receives a notification. Supports
   * "default" for the default notification sound of the device or the filename of a
   * sound resource bundled in the app.
   * Sound files must reside in `/res/raw/`.
   *
   * **Platforms:** Android
   */
  sound?: string;

  /**
   * The notification's title.
   *
   * **Platforms:** iOS, Android, Web
   */
  title?: string;

  /**
   * The key to the body string in the app's string resources to use to localize
   * the body text to the user's current localization.
   *
   * **iOS:** Corresponds to `loc-key` in the APNs payload. See
   * {@link https://developer.apple.com/library/content/documentation/NetworkingInternet/Conceptual/RemoteNotificationsPG/PayloadKeyReference.html |
   * Payload Key Reference} and
   * {@link https://developer.apple.com/library/content/documentation/NetworkingInternet/Conceptual/RemoteNotificationsPG/CreatingtheNotificationPayload.html#//apple_ref/doc/uid/TP40008194-CH10-SW9 |
   * Localizing the Content of Your Remote Notifications} for more information.
   *
   * **Android:** See
   * {@link http://developer.android.com/guide/topics/resources/string-resource.html | String Resources}
   * for more information.
   *
   * **Platforms:** iOS, Android
   */
  bodyLocKey?: string;

  /**
   * Variable string values to be used in place of the format specifiers in
   * `body_loc_key` to use to localize the body text to the user's current
   * localization.
   *
   * The value should be a stringified JSON array.
   *
   * **iOS:** Corresponds to `loc-args` in the APNs payload. See
   * {@link https://developer.apple.com/library/content/documentation/NetworkingInternet/Conceptual/RemoteNotificationsPG/PayloadKeyReference.html |
   * Payload Key Reference} and
   * {@link https://developer.apple.com/library/content/documentation/NetworkingInternet/Conceptual/RemoteNotificationsPG/CreatingtheNotificationPayload.html#//apple_ref/doc/uid/TP40008194-CH10-SW9 |
   * Localizing the Content of Your Remote Notifications} for more information.
   *
   * **Android:** See
   * {@link http://developer.android.com/guide/topics/resources/string-resource.html#FormattingAndStyling |
   * Formatting and Styling} for more information.
   *
   * **Platforms:** iOS, Android
   */
  bodyLocArgs?: string;

  /**
   * Action associated with a user click on the notification. If specified, an
   * activity with a matching Intent Filter is launched when a user clicks on the
   * notification.
   *
   *   * **Platforms:** Android
   */
  clickAction?: string;

  /**
   * The key to the title string in the app's string resources to use to localize
   * the title text to the user's current localization.
   *
   * **iOS:** Corresponds to `title-loc-key` in the APNs payload. See
   * {@link https://developer.apple.com/library/content/documentation/NetworkingInternet/Conceptual/RemoteNotificationsPG/PayloadKeyReference.html |
   * Payload Key Reference} and
   * {@link https://developer.apple.com/library/content/documentation/NetworkingInternet/Conceptual/RemoteNotificationsPG/CreatingtheNotificationPayload.html#//apple_ref/doc/uid/TP40008194-CH10-SW9 |
   * Localizing the Content of Your Remote Notifications} for more information.
   *
   * **Android:** See
   * {@link http://developer.android.com/guide/topics/resources/string-resource.html | String Resources}
   * for more information.
   *
   * **Platforms:** iOS, Android
   */
  titleLocKey?: string;

  /**
   * Variable string values to be used in place of the format specifiers in
   * `title_loc_key` to use to localize the title text to the user's current
   * localization.
   *
   * The value should be a stringified JSON array.
   *
   * **iOS:** Corresponds to `title-loc-args` in the APNs payload. See
   * {@link https://developer.apple.com/library/content/documentation/NetworkingInternet/Conceptual/RemoteNotificationsPG/PayloadKeyReference.html |
   * Payload Key Reference} and
   * {@link https://developer.apple.com/library/content/documentation/NetworkingInternet/Conceptual/RemoteNotificationsPG/CreatingtheNotificationPayload.html#//apple_ref/doc/uid/TP40008194-CH10-SW9 |
   * Localizing the Content of Your Remote Notifications} for more information.
   *
   * **Android:** See
   * {@link http://developer.android.com/guide/topics/resources/string-resource.html#FormattingAndStyling |
   * Formatting and Styling} for more information.
   *
   * **Platforms:** iOS, Android
   */
  titleLocArgs?: string;
  [key: string]: string | undefined;
}

/**
 * Interface representing a Firebase Cloud Messaging message payload. One or
 * both of the `data` and `notification` keys are required.
 *
 * See {@link https://firebase.google.com/docs/cloud-messaging/send-message | Build send requests}
 * for code samples and detailed documentation.
 */
export interface MessagingPayload {

  /**
   * The data message payload.
   */
  data?: DataMessagePayload;

  /**
   * The notification message payload.
   */
  notification?: NotificationMessagePayload;
}

/**
 * Interface representing the options that can be provided when sending a
 * message via the FCM legacy APIs.
 *
 * See {@link https://firebase.google.com/docs/cloud-messaging/send-message | Build send requests}
 * for code samples and detailed documentation.
 */
export interface MessagingOptions {

  /**
   * Whether or not the message should actually be sent. When set to `true`,
   * allows developers to test a request without actually sending a message. When
   * set to `false`, the message will be sent.
   *
   * **Default value:** `false`
   */
  dryRun?: boolean;

  /**
   * The priority of the message. Valid values are `"normal"` and `"high".` On
   * iOS, these correspond to APNs priorities `5` and `10`.
   *
   * By default, notification messages are sent with high priority, and data
   * messages are sent with normal priority. Normal priority optimizes the client
   * app's battery consumption and should be used unless immediate delivery is
   * required. For messages with normal priority, the app may receive the message
   * with unspecified delay.
   *
   * When a message is sent with high priority, it is sent immediately, and the
   * app can wake a sleeping device and open a network connection to your server.
   *
   * For more information, see
   * {@link https://firebase.google.com/docs/cloud-messaging/concept-options#setting-the-priority-of-a-message |
   * Setting the priority of a message}.
   *
   * **Default value:** `"high"` for notification messages, `"normal"` for data
   * messages
   */
  priority?: string;

  /**
   * How long (in seconds) the message should be kept in FCM storage if the device
   * is offline. The maximum time to live supported is four weeks, and the default
   * value is also four weeks. For more information, see
   * {@link https://firebase.google.com/docs/cloud-messaging/concept-options#ttl | Setting the lifespan of a message}.
   *
   * **Default value:** `2419200` (representing four weeks, in seconds)
   */
  timeToLive?: number;

  /**
   * String identifying a group of messages (for example, "Updates Available")
   * that can be collapsed, so that only the last message gets sent when delivery
   * can be resumed. This is used to avoid sending too many of the same messages
   * when the device comes back online or becomes active.
   *
   * There is no guarantee of the order in which messages get sent.
   *
   * A maximum of four different collapse keys is allowed at any given time. This
   * means FCM server can simultaneously store four different
   * send-to-sync messages per client app. If you exceed this number, there is no
   * guarantee which four collapse keys the FCM server will keep.
   *
   * **Default value:** None
   */
  collapseKey?: string;

  /**
   * On iOS, use this field to represent `mutable-content` in the APNs payload.
   * When a notification is sent and this is set to `true`, the content of the
   * notification can be modified before it is displayed, using a
   * {@link https://developer.apple.com/reference/usernotifications/unnotificationserviceextension |
   * Notification Service app extension}.
   *
   * On Android and Web, this parameter will be ignored.
   *
   * **Default value:** `false`
   */
  mutableContent?: boolean;

  /**
   * On iOS, use this field to represent `content-available` in the APNs payload.
   * When a notification or data message is sent and this is set to `true`, an
   * inactive client app is awoken. On Android, data messages wake the app by
   * default. On Chrome, this flag is currently not supported.
   *
   * **Default value:** `false`
   */
  contentAvailable?: boolean;

  /**
   * The package name of the application which the registration tokens must match
   * in order to receive the message.
   *
   * **Default value:** None
   */
  restrictedPackageName?: string;
  [key: string]: any | undefined;
}

/**
 * Interface representing the server response from the
 * {@link Messaging.subscribeToTopic} and {@link Messaging.unsubscribeFromTopic}
 * methods.
 *
 * See
 * {@link https://firebase.google.com/docs/cloud-messaging/manage-topics |
 * Manage topics from the server} for code samples and detailed documentation.
 */
export interface MessagingTopicManagementResponse {
  /**
   * The number of registration tokens that could not be subscribed to the topic
   * and resulted in an error.
   */
  failureCount: number;

  /**
   * The number of registration tokens that were successfully subscribed to the
   * topic.
   */
  successCount: number;

  /**
   * An array of errors corresponding to the provided registration token(s). The
   * length of this array will be equal to {@link MessagingTopicManagementResponse.failureCount}.
   */
  errors: FirebaseArrayIndexError[];
}

/**
 * Interface representing the server response from the
 * {@link Messaging.sendEach} and {@link Messaging.sendEachForMulticast} methods.
 */
export interface BatchResponse {

  /**
   * An array of responses, each corresponding to a message.
   */
  responses: SendResponse[];

  /**
   * The number of messages that were successfully handed off for sending.
   */
  successCount: number;

  /**
   * The number of messages that resulted in errors when sending.
   */
  failureCount: number;
}

/**
 * Interface representing the status of an individual message that was sent as
 * part of a batch request.
 */
export interface SendResponse {
  /**
   * A boolean indicating if the message was successfully handed off to FCM or
   * not. When true, the `messageId` attribute is guaranteed to be set. When
   * false, the `error` attribute is guaranteed to be set.
   */
  success: boolean;

  /**
   * A unique message ID string, if the message was handed off to FCM for
   * delivery.
   *
   */
  messageId?: string;

  /**
   * An error, if the message was not handed off to FCM successfully.
   */
  error?: FirebaseError;
}