declare module 'vue-gtag-next' {
  import { Route } from 'vue-router/types/router';
  import VueRouter from 'vue-router';
  import { App, Ref } from 'vue';

  /**
   * Types copied from @types/gtag.js.
   *
   * @see https://www.npmjs.com/package/@types/gtag.js
   */
  namespace Gtag {
    interface Gtag {
      (
        command: 'config',
        targetId: string,
        config?: ControlParams | EventParams | CustomParams
      ): void;
      (command: 'set', config: CustomParams): void;
      (command: 'js', config: Date): void;
      (
        command: 'event',
        eventName: EventNames | string,
        eventParams?: ControlParams | EventParams | CustomParams
      ): void;
    }

    interface CustomParams {
      [key: string]: any;
    }

    interface ControlParams {
      groups?: string | string[];
      send_to?: string | string[];
      event_callback?: () => void;
      event_timeout?: number;
    }

    type EventNames =
      | 'add_payment_info'
      | 'add_to_cart'
      | 'add_to_wishlist'
      | 'begin_checkout'
      | 'checkout_progress'
      | 'exception'
      | 'generate_lead'
      | 'login'
      | 'page_view'
      | 'purchase'
      | 'refund'
      | 'remove_from_cart'
      | 'screen_view'
      | 'search'
      | 'select_content'
      | 'set_checkout_option'
      | 'share'
      | 'sign_up'
      | 'timing_complete'
      | 'view_item'
      | 'view_item_list'
      | 'view_promotion'
      | 'view_search_results';

    interface EventParams {
      checkout_option?: string;
      checkout_step?: number;
      content_id?: string;
      content_type?: string;
      coupon?: string;
      currency?: string;
      description?: string;
      fatal?: boolean;
      items?: Item[];
      method?: string;
      number?: string;
      promotions?: Promotion[];
      screen_name?: string;
      search_term?: string;
      shipping?: Currency;
      tax?: Currency;
      transaction_id?: string;
      value?: number;
      event_label?: string;
      event_category?: string;
    }

    type Currency = string | number;

    interface Item {
      brand?: string;
      category?: string;
      creative_name?: string;
      creative_slot?: string;
      id?: string;
      location_id?: string;
      name?: string;
      price?: Currency;
      quantity?: number;
    }

    interface Promotion {
      creative_name?: string;
      creative_slot?: string;
      id?: string;
      name?: string;
    }
  }

  export interface PageView {
    /** The page's title. */
    page_title?: string;
    /** The page's URL. */
    page_location?: string;
    /** The path portion of location. This value must start with a slash (/) character. */
    page_path?: string;
  }

  export interface ScreenView {
    /** The name of the screen. */
    screen_name: string;
    /** The name of the application. */
    app_name: string;
  }

  /**
   * @see https://developers.google.com/analytics/devguides/collection/gtagjs/enhanced-ecommerce#action_data
   */
  export interface EcommerceAction {
    /** Unique ID for the transaction. */
    transaction_id: string;
    /** The store or affiliation from which this transaction occurred */
    affiliation?: string;
    /** Value (i.e., revenue) associated with the event */
    value?: number;
    /** Tax amount */
    tax?: number;
    /** Shipping cost */
    shipping?: number;
    /** The array containing the associated products */
    items?: Gtag.Item[];
    /** The step (a number) in the checkout process */
    checkout_step?: number;
    /** Checkout option (i.e. selected payment method) */
    checkout_option?: string;
  }

  export interface Linker {
    domains: string[];
    decorate_forms?: boolean;
    accept_incoming?: boolean;
    url_position?: 'fragment' | 'query';
  }

  export interface Exception {
    /** A description of the error. */
    description?: string;
    /** true if the error was fatal. */
    fatal?: boolean;
  }

  export interface Timing {
    /** A string to identify the variable being recorded (e.g. 'load'). */
    name: string;
    /** The number of milliseconds in elapsed time to report to Google Analytics (e.g. 20). */
    value: number;
    /** A string for categorizing all user timing variables into logical groups (e.g. 'JS Dependencies'). */
    event_category?: string;
    /** A string that can be used to add flexibility in visualizing user timings in the reports (e.g. 'Google CDN'). */
    event_label?: string;
  }

  export type Dictionary<T> = { [key: string]: T };

  export interface VueGtag {
    /**
     * Initialize and configure settings for a particular product account.
     *
     * @see https://developers.google.com/gtagjs/devguide/configure
     */
    config(
      config?: Gtag.ControlParams | Gtag.EventParams | Gtag.CustomParams
    ): void;

    /**
     * Configure a map of custom dimensions and metrics.
     *
     * @see https://developers.google.com/analytics/devguides/collection/gtagjs/custom-dims-mets
     */
    customMap(map: Dictionary<string>): void;

    disable(value?: boolean): void;

    /**
     * Send a Google Analytics Event.
     *
     * @see https://developers.google.com/analytics/devguides/collection/gtagjs/events
     *
     * @param action string that will appear as the event action in Google Analytics Event reports
     * @param eventParams
     */
    event(
      action: Gtag.EventNames | string,
      eventParams?: Gtag.ControlParams | Gtag.EventParams | Gtag.CustomParams
    ): void;

    /**
     * Measure an exception.
     *
     * @see https://developers.google.com/analytics/devguides/collection/gtagjs/exceptions
     */
    exception(ex: Exception): void;

    /**
     * Automatically link domains.
     *
     * @see https://developers.google.com/analytics/devguides/collection/gtagjs/cross-domain#automatically_link_domains
     */
    linker(config: Linker): void;

    /**
     * Send an ad-hoc Google Analytics pageview.
     *
     * @see https://developers.google.com/analytics/devguides/collection/gtagjs/pages
     */
    pageview(pageView: PageView | string): void;

    /**
     * Measure a transaction.
     *
     * @see https://developers.google.com/analytics/devguides/collection/gtagjs/enhanced-ecommerce#measure_purchases
     */
    purchase(purchase: EcommerceAction): void;

    /**
     * Measure a full refund of a transaction.
     *
     * @see https://developers.google.com/analytics/devguides/collection/gtagjs/enhanced-ecommerce#measure_refunds
     */
    refund(refund: EcommerceAction): void;

    /**
     * Send a Google Analytics screen view.
     *
     * @see https://developers.google.com/analytics/devguides/collection/gtagjs/screens
     */
    screenview(screenView: ScreenView): void;

    /**
     * Set parameters that will be associated with every subsequent event on the page.
     *
     * @see https://developers.google.com/gtagjs/devguide/configure#send_data_on_every_event_with_set
     */
    set(config: Gtag.CustomParams): void;

    /**
     * Send user timing information to Google Analytics.
     *
     * @see https://developers.google.com/analytics/devguides/collection/gtagjs/user-timings
     */
    time(timing: Timing): void;
  }

  export interface DomainConfig {
    id: string;
    params?: Gtag.ControlParams | Gtag.EventParams | Gtag.CustomParams;
  }

  export interface Options {
    property?: DomainConfig | DomainConfig[];
    /** defaults to true */
    isEnabled?: boolean;
    /** defaults to false */
    disableScriptLoader?: boolean;
    /** defaults to false */
    useDebugger?: boolean;
    /** defaults to 'gtag' */
    globalObjectName?: string;
    /** defaults to 'dataLayer' */
    dataLayerName?: string;
    /** defaults to 'https://www.googletagmanager.com/gtag/js' */
    resourceURL?: string;
    /** defaults to 'https://www.googletagmanager.com' */
    preconnectOrigin?: string;
    appName?: string;
    appId?: string;
    appVersion?: string;
  }

  export interface RouterOptions {
    template?: (to: Route, from?: Route) => PageView;
    /** defaults to false */
    useScreenview?: boolean;
    /** defaults to true */
    skipSamePath?: boolean;
  }

  export const isReady: Ref<boolean>;

  export const isTracking: Ref<boolean>;

  export function useState(): {
    [K in keyof Options]: Ref<Options[K]>;
  };

  export function useGtag(): VueGtag;

  export function trackRouter(router: VueRouter, options?: RouterOptions): void;

  export default class VueGtagPlugin {
    static install(app: App, options: Options): void;
  }

  module '@vue/runtime-core' {
    interface ComponentCustomProperties {
      $gtag: VueGtag;
    }
  }
}