const version = process.env.VERSION || '[master]';
const source = process.env.SOURCE_LINK || 'https://github.com/productionwentdown/dri';

const defaultConfig = {
  merged: false,

  registryHost: process.env.VUE_APP_REGISTRY_HOST,
  registryAPI: process.env.VUE_APP_REGISTRY_API,

  repositoriesPerPage: process.env.VUE_APP_REPOSITORIES_PER_PAGE,
  tagsPerPage: process.env.VUE_APP_TAGS_PER_PAGE,

  usePortusExplore: process.env.VUE_APP_USE_PORTUS_EXPLORE,
};

async function config() {
  if (defaultConfig.merged) {
    return defaultConfig;
  }

  try {
    const response = await fetch('/config.json');
    const jsonConfig = await response.json();
    defaultConfig.merged = true;
    return Object.assign(defaultConfig, jsonConfig);
  } catch (_) {
    defaultConfig.merged = true;
    return defaultConfig;
  }
}

async function registryHost() {
  const c = await config();
  if (c.registryHost) {
    return c.registryHost;
  }
  return window.location.host;
}

async function registryAPI() {
  const c = await config();
  if (c.registryAPI) {
    return c.registryAPI;
  }
  const host = await registryHost();
  // assume API uses the same protocol as the page
  // this is because browsers don't allow mixed content
  // if a HTTPS API needs to be accessed over HTTP, configure registryAPI
  return `${window.location.protocol}//${host}`;
}

async function usePortusExplore() {
  const c = await config();
  if (c.registryAPI) {
    return c.registryAPI;
  }
  return false;
}

async function repositoriesPerPage() {
  const c = await config();
  try {
    const n = parseInt(c.repositoriesPerPage, 10);
    if (n > 0) return n;
  } catch (_) {
    return 0;
  }
  return 0;
}

async function tagsPerPage() {
  const c = await config();
  try {
    const n = parseInt(c.tagsPerPage, 10);
    if (n > 0) return n;
  } catch (_) {
    return 0;
  }
  return 0;
}

export {
  version,
  source,
  registryHost,
  registryAPI,
  repositoriesPerPage,
  tagsPerPage,
  usePortusExplore,
};