/**

 * 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

 */

import type {ReactNodeList, OffscreenMode, Wakeable} from 'shared/ReactTypes';

import type {Lanes} from './ReactFiberLane';

import type {SpawnedCachePool} from './ReactFiberCacheComponent';

import type {Fiber} from './ReactInternalTypes';

import type {

  Transition,

  TracingMarkerInstance,

} from './ReactFiberTracingMarkerComponent';

import type {RetryQueue} from './ReactFiberSuspenseComponent';

export type OffscreenProps = {

  // TODO: Pick an API before exposing the Offscreen type. I've chosen an enum

  // for now, since we might have multiple variants. For example, hiding the

  // content without changing the layout.

  //

  // Default mode is visible. Kind of a weird default for a component

  // called "Offscreen." Possible alt: <Visibility />?

  mode?: OffscreenMode | null | void,

  children?: ReactNodeList,

};

// We use the existence of the state object as an indicator that the component

// is hidden.

export type OffscreenState = {

  // TODO: This doesn't do anything, yet. It's always NoLanes. But eventually it

  // will represent the pending work that must be included in the render in

  // order to unhide the component.

  baseLanes: Lanes,

  cachePool: SpawnedCachePool | null,

};

export type OffscreenQueue = {

  transitions: Array<Transition> | null,

  markerInstances: Array<TracingMarkerInstance> | null,

  retryQueue: RetryQueue | null,

};

type OffscreenVisibility = number;

export const OffscreenVisible = /*                     */ 0b001;

export const OffscreenDetached = /*                    */ 0b010;

export const OffscreenPassiveEffectsConnected = /*     */ 0b100;

export type OffscreenInstance = {

  _pendingVisibility: OffscreenVisibility,

  _visibility: OffscreenVisibility,

  _pendingMarkers: Set<TracingMarkerInstance> | null,

  _transitions: Set<Transition> | null,

  _retryCache: WeakSet<Wakeable> | Set<Wakeable> | null,

  // Represents the current Offscreen fiber

  _current: Fiber | null,

  detach: () => void,

  attach: () => void,

};

export function isOffscreenManual(offscreenFiber: Fiber): boolean {

  return (

    offscreenFiber.memoizedProps !== null &&

    offscreenFiber.memoizedProps.mode === 'manual'

  );

}