/**
 * 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
 */

import type {ReadonlySignal, Signal} from '@lexical/extension/signals';
import type {EditorState, LexicalEditor, LexicalExtension} from 'lexical';

export type HotContext = {
  readonly data: {[string]: unknown},
};

interface HMRInit {
  restoreCount: Signal<number>;
}

export type HMROutput = {
  restoreCount: ReadonlySignal<number>,
};

export type HMRConfig = {
  hot: HotContext | null,
  id?: string,
};

export interface HMRHistoryStateEntry {
  editor: LexicalEditor;
  editorState: EditorState;
}

export interface HMRHistoryState {
  current: null | HMRHistoryStateEntry;
  redoStack: HMRHistoryStateEntry[];
  undoStack: HMRHistoryStateEntry[];
}

declare export var HMRExtension: LexicalExtension<
  HMRConfig,
  '@lexical/extension/HMR',
  HMROutput,
  {restoreCount: Signal<number>},
>;