/**
 * Copyright (c) Meta Platforms, Inc. and affiliates.
 *
 * This source code is licensed under the MIT license found in the
 * LICENSE file in the root directory of this source tree.
 *
 * @flow strict-local
 * @format
 */

import type {HostComponent} from '../../Renderer/shims/ReactNativeTypes';
import type {EventSubscription} from '../../vendor/emitter/EventEmitter';
import type {ElementRef} from 'react';

// Events that are only supported on Android.
type AccessibilityEventDefinitionsAndroid = {
  accessibilityServiceChanged: [boolean],
};

// Events that are only supported on iOS.
type AccessibilityEventDefinitionsIOS = {
  announcementFinished: [{announcement: string, success: boolean}],
  boldTextChanged: [boolean],
  grayscaleChanged: [boolean],
  invertColorsChanged: [boolean],
  reduceTransparencyChanged: [boolean],
};

type AccessibilityEventDefinitions = {
  ...AccessibilityEventDefinitionsAndroid,
  ...AccessibilityEventDefinitionsIOS,
  change: [boolean], // screenReaderChanged
  reduceMotionChanged: [boolean],
  screenReaderChanged: [boolean],
};

type AccessibilityEventTypes = 'click' | 'focus';
/**
 * Sometimes it's useful to know whether or not the device has a screen reader
 * that is currently active. The `AccessibilityInfo` API is designed for this
 * purpose. You can use it to query the current state of the screen reader as
 * well as to register to be notified when the state of the screen reader
 * changes.
 *
 * See https://reactnative.dev/docs/accessibilityinfo
 */
export interface AccessibilityInfo {
  /**
   * Query whether bold text is currently enabled.
   *
   * Returns a promise which resolves to a boolean.
   * The result is `true` when bold text is enabled and `false` otherwise.
   *
   * See https://reactnative.dev/docs/accessibilityinfo#isBoldTextEnabled
   */
  isBoldTextEnabled: () => Promise<boolean>;

  /**
   * Query whether grayscale is currently enabled.
   *
   * Returns a promise which resolves to a boolean.
   * The result is `true` when grayscale is enabled and `false` otherwise.
   *
   * See https://reactnative.dev/docs/accessibilityinfo#isGrayscaleEnabled
   */
  isGrayscaleEnabled: () => Promise<boolean>;

  /**
   * Query whether inverted colors are currently enabled.
   *
   * Returns a promise which resolves to a boolean.
   * The result is `true` when invert color is enabled and `false` otherwise.
   *
   * See https://reactnative.dev/docs/accessibilityinfo#isInvertColorsEnabled
   */
  isInvertColorsEnabled: () => Promise<boolean>;

  /**
   * Query whether reduced motion is currently enabled.
   *
   * Returns a promise which resolves to a boolean.
   * The result is `true` when a reduce motion is enabled and `false` otherwise.
   *
   * See https://reactnative.dev/docs/accessibilityinfo#isReduceMotionEnabled
   */
  isReduceMotionEnabled: () => Promise<boolean>;

  /**
   * Query whether reduce motion and prefer cross-fade transitions settings are currently enabled.
   *
   * Returns a promise which resolves to a boolean.
   * The result is `true` when prefer cross-fade transitions is enabled and `false` otherwise.
   *
   * See https://reactnative.dev/docs/accessibilityinfo#prefersCrossFadeTransitions
   */
  prefersCrossFadeTransitions: () => Promise<boolean>;

  /**
   * Query whether reduced transparency is currently enabled.
   *
   * Returns a promise which resolves to a boolean.
   * The result is `true` when a reduce transparency is enabled and `false` otherwise.
   *
   * See https://reactnative.dev/docs/accessibilityinfo#isReduceTransparencyEnabled
   */
  isReduceTransparencyEnabled: () => Promise<boolean>;

  /**
   * Query whether a screen reader is currently enabled.
   *
   * Returns a promise which resolves to a boolean.
   * The result is `true` when a screen reader is enabled and `false` otherwise.
   *
   * See https://reactnative.dev/docs/accessibilityinfo#isScreenReaderEnabled
   */
  isScreenReaderEnabled: () => Promise<boolean>;

  /**
   * Query whether Accessibility Service is currently enabled.
   *
   * Returns a promise which resolves to a boolean.
   * The result is `true` when any service is enabled and `false` otherwise.
   *
   * @platform android
   *
   * See https://reactnative.dev/docs/accessibilityinfo/#isaccessibilityserviceenabled-android
   */
  isAccessibilityServiceEnabled: () => Promise<boolean>;

  /**
   * Add an event handler. Supported events:
   *
   * - `reduceMotionChanged`: Fires when the state of the reduce motion toggle changes.
   *   The argument to the event handler is a boolean. The boolean is `true` when a reduce
   *   motion is enabled (or when "Transition Animation Scale" in "Developer options" is
   *   "Animation off") and `false` otherwise.
   * - `screenReaderChanged`: Fires when the state of the screen reader changes. The argument
   *   to the event handler is a boolean. The boolean is `true` when a screen
   *   reader is enabled and `false` otherwise.
   *
   * These events are only supported on iOS:
   *
   * - `boldTextChanged`: iOS-only event. Fires when the state of the bold text toggle changes.
   *   The argument to the event handler is a boolean. The boolean is `true` when a bold text
   *   is enabled and `false` otherwise.
   * - `grayscaleChanged`: iOS-only event. Fires when the state of the gray scale toggle changes.
   *   The argument to the event handler is a boolean. The boolean is `true` when a gray scale
   *   is enabled and `false` otherwise.
   * - `invertColorsChanged`: iOS-only event. Fires when the state of the invert colors toggle
   *   changes. The argument to the event handler is a boolean. The boolean is `true` when a invert
   *   colors is enabled and `false` otherwise.
   * - `reduceTransparencyChanged`: iOS-only event. Fires when the state of the reduce transparency
   *   toggle changes.  The argument to the event handler is a boolean. The boolean is `true`
   *   when a reduce transparency is enabled and `false` otherwise.
   * - `announcementFinished`: iOS-only event. Fires when the screen reader has
   *   finished making an announcement. The argument to the event handler is a
   *   dictionary with these keys:
   *     - `announcement`: The string announced by the screen reader.
   *     - `success`: A boolean indicating whether the announcement was
   *       successfully made.
   *
   * See https://reactnative.dev/docs/accessibilityinfo#addeventlistener
   */
  addEventListener<K: $Keys<AccessibilityEventDefinitions>>(
    eventName: K,
    handler: (...$ElementType<AccessibilityEventDefinitions, K>) => void,
  ): EventSubscription;

  /**
   * Set accessibility focus to a React component.
   *
   * See https://reactnative.dev/docs/accessibilityinfo#setaccessibilityfocus
   */
  setAccessibilityFocus: (reactTag: number) => void;

  /**
   * Send a named accessibility event to a HostComponent.
   */
  sendAccessibilityEvent: (
    handle: ElementRef<HostComponent<mixed>>,
    eventType: AccessibilityEventTypes,
  ) => void;

  /**
   * Post a string to be announced by the screen reader.
   *
   * See https://reactnative.dev/docs/accessibilityinfo#announceforaccessibility
   */
  announceForAccessibility: (announcement: string) => void;

  /**
   * Post a string to be announced by the screen reader.
   * - `announcement`: The string announced by the screen reader.
   * - `options`: An object that configures the reading options.
   *   - `queue`: The announcement will be queued behind existing announcements. iOS only.
   */
  announceForAccessibilityWithOptions: (
    announcement: string,
    options: {queue?: boolean},
  ) => void;

  /**
   * Get the recommended timeout for changes to the UI needed by this user.
   *
   * See https://reactnative.dev/docs/accessibilityinfo#getrecommendedtimeoutmillis
   */
  getRecommendedTimeoutMillis: (originalTimeout: number) => Promise<number>;
}