const getCurrentScriptSource = require('./getCurrentScriptSource.js');

/**
 * @typedef {Object} SocketUrlParts
 * @property {string} [auth]
 * @property {string} hostname
 * @property {string} [protocol]
 * @property {string} pathname
 * @property {string} [port]
 */

/**
 * Parse current location and Webpack's `__resourceQuery` into parts that can create a valid socket URL.
 * @param {string} [resourceQuery] The Webpack `__resourceQuery` string.
 * @param {import('./getWDSMetadata').WDSMetaObj} [metadata] The parsed WDS metadata object.
 * @returns {SocketUrlParts} The parsed URL parts.
 * @see https://webpack.js.org/api/module-variables/#__resourcequery-webpack-specific
 */
function getSocketUrlParts(resourceQuery, metadata) {
  if (typeof metadata === 'undefined') {
    metadata = {};
  }

  /** @type {SocketUrlParts} */
  let urlParts = {};

  // If the resource query is available,
  // parse it and ignore everything we received from the script host.
  if (resourceQuery) {
    const parsedQuery = {};
    const searchParams = new URLSearchParams(resourceQuery.slice(1));
    searchParams.forEach(function (value, key) {
      parsedQuery[key] = value;
    });

    urlParts.hostname = parsedQuery.sockHost;
    urlParts.pathname = parsedQuery.sockPath;
    urlParts.port = parsedQuery.sockPort;

    // Make sure the protocol from resource query has a trailing colon
    if (parsedQuery.sockProtocol) {
      urlParts.protocol = parsedQuery.sockProtocol + ':';
    }
  } else {
    const scriptSource = getCurrentScriptSource();

    let url = {};
    try {
      // The placeholder `baseURL` with `window.location.href`,
      // is to allow parsing of path-relative or protocol-relative URLs,
      // and will have no effect if `scriptSource` is a fully valid URL.
      url = new URL(scriptSource, window.location.href);
    } catch (e) {
      // URL parsing failed, do nothing.
      // We will still proceed to see if we can recover using `resourceQuery`
    }

    // Parse authentication credentials in case we need them
    if (url.username) {
      // Since HTTP basic authentication does not allow empty username,
      // we only include password if the username is not empty.
      // Result: <username> or <username>:<password>
      urlParts.auth = url.username;
      if (url.password) {
        urlParts.auth += ':' + url.password;
      }
    }

    // `file://` URLs has `'null'` origin
    if (url.origin !== 'null') {
      urlParts.hostname = url.hostname;
    }

    urlParts.protocol = url.protocol;
    urlParts.port = url.port;
  }

  if (!urlParts.pathname) {
    if (metadata.version === 4) {
      // This is hard-coded in WDS v4
      urlParts.pathname = '/ws';
    } else {
      // This is hard-coded in WDS v3
      urlParts.pathname = '/sockjs-node';
    }
  }

  // Check for IPv4 and IPv6 host addresses that correspond to any/empty.
  // This is important because `hostname` can be empty for some hosts,
  // such as 'about:blank' or 'file://' URLs.
  const isEmptyHostname =
    urlParts.hostname === '0.0.0.0' || urlParts.hostname === '[::]' || !urlParts.hostname;
  // We only re-assign the hostname if it is empty,
  // and if we are using HTTP/HTTPS protocols.
  if (
    isEmptyHostname &&
    window.location.hostname &&
    window.location.protocol.indexOf('http') === 0
  ) {
    urlParts.hostname = window.location.hostname;
  }

  // We only re-assign `protocol` when `protocol` is unavailable,
  // or if `hostname` is available and is empty,
  // since otherwise we risk creating an invalid URL.
  // We also do this when 'https' is used as it mandates the use of secure sockets.
  if (
    !urlParts.protocol ||
    (urlParts.hostname && (isEmptyHostname || window.location.protocol === 'https:'))
  ) {
    urlParts.protocol = window.location.protocol;
  }

  // We only re-assign port when it is not available
  if (!urlParts.port) {
    urlParts.port = window.location.port;
  }

  if (!urlParts.hostname || !urlParts.pathname) {
    throw new Error(
      [
        '[React Refresh] Failed to get an URL for the socket connection.',
        "This usually means that the current executed script doesn't have a `src` attribute set.",
        'You should either specify the socket path parameters under the `devServer` key in your Webpack config, or use the `overlay` option.',
        'https://github.com/pmmmwh/react-refresh-webpack-plugin/blob/main/docs/API.md#overlay',
      ].join('\n')
    );
  }

  return {
    auth: urlParts.auth,
    hostname: urlParts.hostname,
    pathname: urlParts.pathname,
    protocol: urlParts.protocol,
    port: urlParts.port || undefined,
  };
}

module.exports = getSocketUrlParts;