import { useCallback } from 'react';

import * as Events from '../utils/events';
import { emitter } from '../EditorEvent';
import type { EditorEvents, ToolbarEvents } from '../constants';

type SubscribableEvent = ToolbarEvents | EditorEvents;

type EventData = {
  [EditorEvents.UpsertLink]: {
    text: string;
    url: string;
  };
  [EditorEvents.EditorChange]: {
    value: string;
    toolbarState: Record<string, boolean>;
  };
  [ToolbarEvents.ApplyLink]: {
    text: string;
    url: string;
  };
};

type EventDataByEventName<T> = T extends keyof EventData ? EventData[T] : void;

/**
 * Hook to subscribe to events for a rich text editor
 * @param editorName - The name of the editor to subscribe to events for
 * @returns An object with two functions: emitEvent and subscribeToEvents
 * @example
 * const { emitEvent, subscribeToEvents } = useRichTextEditorEvents('editorName');
 * subscribeToEvents(EditorEvents.EditorFocus, () => {
 *   console.log('Editor focused');
 * });
 * emitEvent({ type: EditorEvents.EditorFocus, data: null });
 */
const useRichTextEditorEvents = (editorName: string) => {
  const normalizeEventName = useCallback(
    (event: string) => `${editorName}/${event}`,
    [editorName]
  );

  const subscribeToEvents = useCallback(
    <TEventName extends SubscribableEvent>(
      eventName: TEventName,
      onEvent: (data: EventDataByEventName<TEventName>) => void
    ) =>
      Events.on(
        emitter,
        normalizeEventName(eventName),
        (eventData: EventDataByEventName<TEventName>) => {
          onEvent(eventData);
        }
      ),
    [normalizeEventName]
  );

  const emitEvent = useCallback(
    <TEventName extends ToolbarEvents>({
      type,
      data,
    }: {
      type: TEventName;
      data: TEventName extends keyof EventData
        ? EventData[TEventName]
        : unknown;
    }) => {
      Events.emit(emitter, normalizeEventName(type), data);
    },
    [normalizeEventName]
  );

  return {
    emitEvent,
    subscribeToEvents,
  };
};

export default useRichTextEditorEvents;