const gh = (path) => new URL(path, 'https://nobsdelivr.private.coffee/gh');

const getJson = (url) =>
  fetch(url, { headers: { Accept: "application/json" } })
    .then((response) => response.json())
    .catch((error) => {
      console.error(error);
    });

async function fetchInstances() {
  const targetTypes = [
    'anonymousoverflow',
    'breezewiki',
    'dumb',
    'eddrit',
    'intellectual',
    'invidious',
    'libmedium',
    'nerdsfornerds',
    'neuters',
    'nitter',
    'photon-reddit',
    'priviblur',
    'quetre',
    'redlib',
    'ruraldictionary',
    'scribe',
  ];

  const instances = targetTypes.reduce((out, type) => {
    out[type] = [];
    return out;
  }, Object.create(null));

  const providers = {
    libredirect: {
      source: 'libredirect/instances/data.json',
      normalize: (result) =>
        Object.entries(result).map(([name, instances]) => ({
          type: name.toLowerCase(),
          instances: instances.clearnet,
        })),
    },

    farside: {
      source: 'benbusby/farside/services.json',
      normalize: (result) =>
        result.map((service) => ({
          type: service.type,
          instances: service.instances
            .filter((instance) => !instance.endsWith('.onion'))
            .concat(service.fallback),
        })),
    },

    fastside: {
      source: 'cofob/fastside/services.json',
      normalize: (result) =>
        result.services.map((service) => ({
          type: service.type,
          instances: service.instances
            .filter((instance) => instance.tags.includes('clearnet'))
            .map((instance) => instance.url),
        })),
    },
  };

  const promises = Object.values(providers).map(async (provider) => {
    const result = await getJson(gh(provider.source));

    if (!result) {
      return [];
    }

    return provider.normalize(result);
  });

  const sources = await Promise.all(promises);

  for (const source of sources.flat()) {
    if (!(source.type in instances)) continue;

    const list = instances[source.type];

    for (const instance of source.instances) {
      const { href } = new URL(instance);

      if (!list.includes(href)) {
        list.push(href);
        list.sort();
      }
    }
  }

  return instances;
}

async function testBackups() {
  const backups = [
    'https://api.npoint.io/6ee2cb1b5a1aa6f10be5',
  ];

  const results = await Promise.all(backups.map((backup) => getJson(backup)));

  for (const index of results.keys()) {
    const result = results[index];

    if (!result) {
      const backup = backups[index];
      console.warn(`Stale backup: ${backup}`);
    }
  }
}