import { client } from 'App/mstore'

const ALLOWED_404 = 'No-file-and-this-is-ok';
const NO_BACKUP_FILE = 'No-efs-file';
export const NO_URLS = 'No-urls-provided';

export async function loadFiles(
  urls: string[],
  onData: (data: Uint8Array) => void,
  canSkip: boolean = false
): Promise<void> {
  if (!urls.length) {
    throw NO_URLS;
  }
  try {
    for (let url of urls) {
      await loadFile(url, onData, urls.length > 1 ? url !== urls[0] : canSkip);
    }
    return Promise.resolve();
  } catch (e) {
    return Promise.reject(e);
  }
}

export async function loadFile(
  url: string,
  onData: (data: Uint8Array) => void,
  canSkip: boolean = false
): Promise<void> {
  return window
    .fetch(url)
    .then((response) => processAPIStreamResponse(response, canSkip))
    .then((data) => onData(data))
    .catch((e) => {
      if (e === ALLOWED_404) {
        return;
      } else {
        throw e;
      }
    });
}

export async function requestEFSDom(sessionId: string) {
  return await requestEFSMobFile(sessionId + '/dom.mob');
}

export async function requestEFSDevtools(sessionId: string) {
  return await requestEFSMobFile(sessionId + '/devtools.mob');
}

export async function requestTarball(url: string) {
  const res = await window.fetch(url);
  if (res.ok) {
    const buf = await res.arrayBuffer();
    return new Uint8Array(buf);
  } else {
    throw new Error(res.status.toString());
  }
}

const urlPattern = /https?:\/\/[a-zA-Z0-9.-]+(:\d+)?\/(\d+)\/session\/\d+/;

function getSiteId(url) {
  const match = url.match(urlPattern);
  return match ? match[2] : null; // match[2] contains the siteId
}

async function requestEFSMobFile(filename: string) {
  const siteId = getSiteId(document.location.href)
  if (siteId) {
    client.forceSiteId(siteId);
    client.setSiteIdCheck(() => ({ siteId }));
  }

  const res = await client.fetch('/unprocessed/' + filename);
  if (res.status >= 400) {
    throw NO_BACKUP_FILE;
  }
  return await processAPIStreamResponse(res, false);
}

const processAPIStreamResponse = (response: Response, skippable: boolean) => {
  return new Promise<ArrayBuffer>((res, rej) => {
    if (response.status === 404 && skippable) {
      return rej(ALLOWED_404);
    }
    if (response.status >= 400) {
      return rej(
        `Bad file status code ${response.status}. Url: ${response.url}`
      );
    }
    res(response.arrayBuffer());
  }).then(async (buf) => new Uint8Array(buf));
};