import axios from 'axios';
import AbortController from 'abort-controller';
import FileType from 'file-type';

export const allowedFormats = ['jpg', 'jpeg', 'png'];
export const requestWaitingTimeInMs = 3 * 1000;

/**
 * This function checks does an image available by url
 */
export const checkImageUrl = async (url: string): Promise<boolean | null> =>
  new Promise((resolve) => {
    try {
      (async () => {
        const controller = new AbortController();
        const { signal } = controller;

        const timeout = setTimeout(() => {
          controller.abort();
        }, requestWaitingTimeInMs);

        signal.addEventListener('abort', () => {
          console.log(
            `Request to URL ${url} cancelled due to server not responding`
          );

          resolve(null);
        });

        const req = await axios.get(url, {
          responseType: 'arraybuffer',
          signal,
        });

        clearTimeout(timeout);

        const buffer = Buffer.from(req.data, 'binary');

        const fileData = await FileType.fromBuffer(buffer);

        const { ext, mime } = fileData ?? {};

        if (ext === undefined || mime === undefined) {
          return resolve(false);
        }

        const fileType = mime.split('/')[0];

        if (fileType !== 'image') {
          return resolve(false);
        }

        if (allowedFormats.includes(ext) === false) {
          return resolve(false);
        }

        return resolve(true);
      })();
    } catch (error) {
      console.error(error);

      return resolve(null);
    }
  });