FxAccountsProfileClient.jsm

/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

/**
 * A client to fetch profile information for a Firefox Account.
 */
 "use strict;"

this.EXPORTED_SYMBOLS = ["FxAccountsProfileClient", "FxAccountsProfileClientError"];

const {classes: Cc, interfaces: Ci, utils: Cu, results: Cr} = Components;

Cu.import("resource://gre/modules/Promise.jsm");
Cu.import("resource://gre/modules/Log.jsm");
Cu.import("resource://gre/modules/FxAccountsCommon.js");
Cu.import("resource://gre/modules/FxAccounts.jsm");
Cu.import("resource://gre/modules/Task.jsm");
Cu.import("resource://services-common/rest.js");

Cu.importGlobalProperties(["URL"]);

/**
 * Create a new FxAccountsProfileClient to be able to fetch Firefox Account profile information.
 *
 * @param {Object} options Options
 *   @param {String} options.serverURL
 *   The URL of the profile server to query.
 *   Example: https://profile.accounts.firefox.com/v1
 *   @param {String} options.token
 *   The bearer token to access the profile server
 * @constructor
 */
this.FxAccountsProfileClient = function(options) {
  if (!options || !options.serverURL) {
    throw new Error("Missing 'serverURL' configuration option");
  }

  this.fxa = options.fxa || fxAccounts;
  // This is a work-around for loop that manages its own oauth tokens.
  // * If |token| is in options we use it and don't attempt any token refresh
  //  on 401. This is for loop.
  // * If |token| doesn't exist we will fetch our own token. This is for the
  //   normal FxAccounts methods for obtaining the profile.
  // We should nuke all |this.token| support once loop moves closer to FxAccounts.
  this.token = options.token;

  try {
    this.serverURL = new URL(options.serverURL);
  } catch (e) {
    throw new Error("Invalid 'serverURL'");
  }
  this.oauthOptions = {
    scope: "profile",
  };
  log.debug("FxAccountsProfileClient: Initialized");
};

this.FxAccountsProfileClient.prototype = {
  /**
   * {nsIURI}
   * The server to fetch profile information from.
   */
  serverURL: null,

  /**
   * Interface for making remote requests.
   */
  _Request: RESTRequest,

  /**
   * Remote request helper which abstracts authentication away.
   *
   * @param {String} path
   *        Profile server path, i.e "/profile".
   * @param {String} [method]
   *        Type of request, i.e "GET".
   * @param {String} [etag]
   *        Optional ETag used for caching purposes.
   * @return Promise
   *         Resolves: {body: Object, etag: Object} Successful response from the Profile server.
   *         Rejects: {FxAccountsProfileClientError} Profile client error.
   * @private
   */
  _createRequest: Task.async(function* (path, method = "GET", etag = null) {
    let token = this.token;
    if (!token) {
      // tokens are cached, so getting them each request is cheap.
      token = yield this.fxa.getOAuthToken(this.oauthOptions);
    }
    try {
      return (yield this._rawRequest(path, method, token, etag));
    } catch (ex) {
      if (!(ex instanceof FxAccountsProfileClientError) || ex.code != 401) {
        throw ex;
      }
      // If this object was instantiated with a token then we don't refresh it.
      if (this.token) {
        throw ex;
      }
      // it's an auth error - assume our token expired and retry.
      log.info("Fetching the profile returned a 401 - revoking our token and retrying");
      yield this.fxa.removeCachedOAuthToken({token});
      token = yield this.fxa.getOAuthToken(this.oauthOptions);
      // and try with the new token - if that also fails then we fail after
      // revoking the token.
      try {
        return (yield this._rawRequest(path, method, token, etag));
      } catch (ex) {
        if (!(ex instanceof FxAccountsProfileClientError) || ex.code != 401) {
          throw ex;
        }
        log.info("Retry fetching the profile still returned a 401 - revoking our token and failing");
        yield this.fxa.removeCachedOAuthToken({token});
        throw ex;
      }
    }
  }),

  /**
   * Remote "raw" request helper - doesn't handle auth errors and tokens.
   *
   * @param {String} path
   *        Profile server path, i.e "/profile".
   * @param {String} method
   *        Type of request, i.e "GET".
   * @param {String} token
   * @param {String} etag
   * @return Promise
   *         Resolves: {body: Object, etag: Object} Successful response from the Profile server
                        or null if 304 is hit (same ETag).
   *         Rejects: {FxAccountsProfileClientError} Profile client error.
   * @private
   */
  _rawRequest(path, method, token, etag) {
    return new Promise((resolve, reject) => {
      let profileDataUrl = this.serverURL + path;
      let request = new this._Request(profileDataUrl);
      method = method.toUpperCase();

      request.setHeader("Authorization", "Bearer " + token);
      request.setHeader("Accept", "application/json");
      if (etag) {
        request.setHeader("If-None-Match", etag);
      }

      request.onComplete = function(error) {
        if (error) {
          reject(new FxAccountsProfileClientError({
            error: ERROR_NETWORK,
            errno: ERRNO_NETWORK,
            message: error.toString(),
          }));
          return;
        }

        let body = null;
        try {
          if (request.response.status == 304) {
            resolve(null);
            return;
          }
          body = JSON.parse(request.response.body);
        } catch (e) {
          reject(new FxAccountsProfileClientError({
            error: ERROR_PARSE,
            errno: ERRNO_PARSE,
            code: request.response.status,
            message: request.response.body,
          }));
          return;
        }

        // "response.success" means status code is 200
        if (request.response.success) {
          resolve({
            body,
            etag: request.response.headers["etag"]
          });
          return;
        }
        reject(new FxAccountsProfileClientError({
          error: body.error || ERROR_UNKNOWN,
          errno: body.errno || ERRNO_UNKNOWN_ERROR,
          code: request.response.status,
          message: body.message || body,
        }));
      };

      if (method === "GET") {
        request.get();
      } else {
        // method not supported
        reject(new FxAccountsProfileClientError({
          error: ERROR_NETWORK,
          errno: ERRNO_NETWORK,
          code: ERROR_CODE_METHOD_NOT_ALLOWED,
          message: ERROR_MSG_METHOD_NOT_ALLOWED,
        }));
      }
    });
  },

  /**
   * Retrieve user's profile from the server
   *
   * @param {String} [etag]
   *        Optional ETag used for caching purposes. (may generate a 304 exception)
   * @return Promise
   *         Resolves: {body: Object, etag: Object} Successful response from the '/profile' endpoint.
   *         Rejects: {FxAccountsProfileClientError} profile client error.
   */
  fetchProfile(etag) {
    log.debug("FxAccountsProfileClient: Requested profile");
    return this._createRequest("/profile", "GET", etag);
  }
};

/**
 * Normalized profile client errors
 * @param {Object} [details]
 *        Error details object
 *   @param {number} [details.code]
 *          Error code
 *   @param {number} [details.errno]
 *          Error number
 *   @param {String} [details.error]
 *          Error description
 *   @param {String|null} [details.message]
 *          Error message
 * @constructor
 */
this.FxAccountsProfileClientError = function(details) {
  details = details || {};

  this.name = "FxAccountsProfileClientError";
  this.code = details.code || null;
  this.errno = details.errno || ERRNO_UNKNOWN_ERROR;
  this.error = details.error || ERROR_UNKNOWN;
  this.message = details.message || null;
};

/**
 * Returns error object properties
 *
 * @returns {{name: *, code: *, errno: *, error: *, message: *}}
 * @private
 */
FxAccountsProfileClientError.prototype._toStringFields = function() {
  return {
    name: this.name,
    code: this.code,
    errno: this.errno,
    error: this.error,
    message: this.message,
  };
};

/**
 * String representation of a profile client error
 *
 * @returns {String}
 */
FxAccountsProfileClientError.prototype.toString = function() {
  return this.name + "(" + JSON.stringify(this._toStringFields()) + ")";
};