import { type EditorProps as DraftEditorProps, EditorState } from 'draft-js';
import { useCallback } from 'react';
import addNewBlockAt from '../utils/addNewBlockAt.js';
import getCurrentBlock from '../utils/getCurrentBlock.js';

type UseReturnHandlerRes = NonNullable<DraftEditorProps['handleReturn']>;

/**
 * Adds a new unstyled block if the user presses the return key.
 */
const useReturnHandler = (
  onChange: (value: EditorState) => void,
  handler: UseReturnHandlerRes
): UseReturnHandlerRes =>
  useCallback<UseReturnHandlerRes>(
    (e, editorState) => {
      const currentBlock = getCurrentBlock(editorState);
      const currentBlockType = currentBlock.getType();

      if (
        currentBlockType.startsWith('atomic') ||
        currentBlockType.startsWith('header')
      ) {
        const nextEditorState = addNewBlockAt(
          editorState,
          currentBlock.getKey()
        );
        onChange(nextEditorState);
        return 'handled';
      }

      return handler(e, editorState);
    },
    [onChange, handler]
  );

export default useReturnHandler;