import toArray from 'tui-code-snippet/collection/toArray';

import { HookCallback } from '@t/editor';
import { Emitter } from '@t/event';

export function addDefaultImageBlobHook(eventEmitter: Emitter) {
  eventEmitter.listen('addImageBlobHook', (blob: File, callback: HookCallback) => {
    const reader = new FileReader();

    reader.onload = ({ target }) => callback(target!.result as string);
    reader.readAsDataURL(blob);
  });
}

export function emitImageBlobHook(eventEmitter: Emitter, blob: File, type: string) {
  const hook: HookCallback = (imageUrl, altText) => {
    eventEmitter.emit('command', 'addImage', {
      imageUrl,
      altText: altText || blob.name || 'image',
    });
  };

  eventEmitter.emit('addImageBlobHook', blob, hook, type);
}

export function pasteImageOnly(items: DataTransferItemList) {
  const images = toArray(items).filter(({ type }) => type.indexOf('image') !== -1);

  if (images.length === 1) {
    const [item] = images;

    if (item) {
      return item.getAsFile();
    }
  }

  return null;
}