/**
 * 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 VirtualizedList from './';
import * as React from 'react';
import { useMemo, useContext } from 'react';
const __DEV__ = process.env.NODE_ENV !== 'production';
type Frame = $ReadOnly<{
  offset: number,
  length: number,
  index: number,
  inLayout: boolean,
}>;
export type ChildListState = $ReadOnly<{
  first: number,
  last: number,
  frames: {
    [key: number]: Frame
  },
}>;

// Data propagated through nested lists (regardless of orientation) that is
// useful for producing diagnostics for usage errors involving nesting (e.g
// missing/duplicate keys).
export type ListDebugInfo = $ReadOnly<{
  cellKey: string,
  listKey: string,
  parent: ?ListDebugInfo,
  // We include all ancestors regardless of orientation, so this is not always
  // identical to the child's orientation.
  horizontal: boolean,
}>;
type Context = $ReadOnly<{
  cellKey: ?string,
  getScrollMetrics: () => {
    contentLength: number,
    dOffset: number,
    dt: number,
    offset: number,
    timestamp: number,
    velocity: number,
    visibleLength: number,
  },
  horizontal: ?boolean,
  getOutermostParentListRef: () => VirtualizedList,
  getNestedChildState: (string) => ?ChildListState,
  registerAsNestedChild: ({
    cellKey: string,
    key: string,
    ref: VirtualizedList,
    parentDebugInfo: ListDebugInfo,
  }) => ?ChildListState,
  unregisterAsNestedChild: ({
    key: string,
    state: ChildListState,
  }) => void,
  debugInfo: ListDebugInfo,
}>;
export const VirtualizedListContext: React.Context<?Context> = React.createContext(null);
if (__DEV__) {
  VirtualizedListContext.displayName = 'VirtualizedListContext';
}

/**
 * Resets the context. Intended for use by portal-like components (e.g. Modal).
 */
declare export function VirtualizedListContextResetter(arg0: {
  children: React.Node
}): React.Node;
/**
 * Sets the context with memoization. Intended to be used by `VirtualizedList`.
 */
declare export function VirtualizedListContextProvider(arg0: {
  children: React.Node,
  value: Context,
}): React.Node;
/**
 * Sets the `cellKey`. Intended to be used by `VirtualizedList` for each cell.
 */
declare export function VirtualizedListCellContextProvider(arg0: {
  cellKey: string,
  children: React.Node,
}): React.Node;