'use strict';

let GitHubishSource = module.exports;

/**
 * Lists GitHub-Like Releases (source tarball & zip)
 *
 * @param {Object} opts
 * @param {String} opts.owner
 * @param {String} opts.repo
 * @param {String} opts.baseurl
 * @param {String} [opts.username]
 * @param {String} [opts.token]
 */
GitHubishSource.getDistributables = async function ({
  owner,
  repo,
  baseurl,
  username = '',
  token = '',
}) {
  if (!owner) {
    throw new Error('missing owner for repo');
  }
  if (!repo) {
    throw new Error('missing repo name');
  }
  if (!baseurl) {
    throw new Error('missing baseurl');
  }

  let url = `${baseurl}/repos/${owner}/${repo}/releases`;
  let opts = {
    headers: {
      'Content-Type': 'appplication/json',
    },
  };

  if (token) {
    let userpass = `${username}:${token}`;
    let basicAuth = btoa(userpass);
    Object.assign(opts.headers, {
      Authorization: `Basic ${basicAuth}`,
    });
  }

  let resp = await fetch(url, opts);
  if (!resp.ok) {
    let headers = Array.from(resp.headers);
    console.error('Bad Resp Headers:', headers);
    let text = await resp.text();
    console.error('Bad Resp Body:', text);
    let msg = `failed to fetch releases from '${baseurl}' with user '${username}'`;
    throw new Error(msg);
  }

  let respText = await resp.text();
  let gHubResp;
  try {
    gHubResp = JSON.parse(respText);
  } catch (e) {
    console.error('Bad Resp JSON:', respText);
    console.error(e.message);
    let msg = `failed to parse releases from '${baseurl}' with user '${username}'`;
    throw new Error(msg);
  }

  let all = {
    releases: [],
    // TODO make this ':baseurl' + ':releasename'
    download: '',
  };

  for (let release of gHubResp) {
    let dists = GitHubishSource.releaseToDistributables(release);
    for (let dist of dists) {
      let updates =
        await GitHubishSource.followDistributableDownloadAttachment(dist);
      Object.assign(dist, updates);
      all.releases.push(dist);
    }
  }

  return all;
};

GitHubishSource.releaseToDistributables = function (ghRelease) {
  let ghTag = ghRelease['tag_name']; // TODO tags aren't always semver / sensical
  let lts = /(\b|_)(lts)(\b|_)/.test(ghRelease['tag_name']);
  let channel = 'stable';
  if (ghRelease['prerelease']) {
    channel = 'beta';
  }
  let date = ghRelease['published_at'] || '';
  date = date.replace(/T.*/, '');

  let urls = [ghRelease.tarball_url, ghRelease.zipball_url];
  let dists = [];
  for (let url of urls) {
    dists.push({
      name: '',
      version: ghTag,
      lts: lts,
      channel: channel,
      date: date,
      os: '*',
      arch: '*',
      libc: '',
      ext: '',
      download: url,
    });
  }

  return dists;
};

GitHubishSource.followDistributableDownloadAttachment = async function (dist) {
  let abortCtrl = new AbortController();
  let resp = await fetch(dist.download, {
    method: 'HEAD',
    redirect: 'follow',
    signal: abortCtrl.signal,
  });
  let headers = Object.fromEntries(resp.headers);

  // Workaround for bug where METHOD changes to GET
  abortCtrl.abort();
  await resp.text().catch(function (err) {
    if (err.name !== 'AbortError') {
      throw err;
    }
  });

  // ex: content-disposition: attachment; filename=BeyondCodeBootcamp-DuckDNS.sh-v1.0.1-0-ga2f4bde.zip
  //  => BeyondCodeBootcamp-DuckDNS.sh-v1.0.1-0-ga2f4bde.zip
  let name = headers['content-disposition'].replace(
    /.*filename=([^;]+)(;|$)/,
    '$1',
  );
  let download = resp.url;

  return { name, download };
};

if (module === require.main) {
  GitHubishSource.getDistributables({
    owner: 'BeyondCodeBootcamp',
    repo: 'DuckDNS.sh',
    baseurl: 'https://api.github.com',
  }).then(function (all) {
    console.info(JSON.stringify(all, null, 2));
  });
}