app.js

/*
 * Copyright (c) 2017 TopCoder, Inc. All rights reserved.
 */

/**
 * Main app script.
 *
 * @author TCSCODER
 * @version 1.0
 */
const Path = require('path');
const _ = require('lodash');
const cors = require('cors');
const express = require('express');
const bodyParser = require('body-parser');
const session = require('express-session');
const cookieParser = require('cookie-parser');
const jwtDecode = require('jwt-decode');
// const secure = require('ssl-express-www');
const config = require('./config');
const routes = require('./routes');
const logger = require('./common/logger');
const errors = require('./common/errors');
const constants = require('./common/constants');
const {getAppHealth} = require('./controllers/AppHealthController');

const app = express();
app.use(cors());
// app.use(secure);
app.use(bodyParser.json());
app.use(bodyParser.urlencoded({ extended: true }));
app.use(session({ secret: config.SESSION_SECRET, resave: false, saveUninitialized: true }));
app.use(cookieParser());

// Load routes
_.forEach(routes, (verbs, path) => {
  _.forEach(verbs, (def, verb) => {
    const controllerPath = Path.join(__dirname, `./controllers/${def.controller}`);
    const method = require(controllerPath)[def.method]; // eslint-disable-line global-require
    if (!method) {
      throw new Error(`${def.method} is undefined`);
    }
    const actions = [];
    if (!def.allowAnonymous) {
      actions.push((req, res, next) => {
        const v3jwt = _.get(req.cookies, constants.JWT_V3_NAME);
        if (v3jwt) {
          const decoded = jwtDecode(v3jwt);
          req.currentUser = {
            handle: decoded.handle.toLowerCase(),
            roles: decoded.roles,
          };
        }
        req.signature = `${def.controller}#${def.method}`;
        next();
      });
    }
    if (def.tcLogin) {
      // middleware to handle TC login
      actions.push((req, res, next) => {
        if (req.session.tcLoginDone) {
          req.session.tcLoginDone = null;
          return next();
        }
        req.session.tcLoginReturnUrl = req.originalUrl;
        const callbackUri = `${config.WEBSITE}${constants.TC_LOGIN_CALLBACK_URL}`;
        return res.redirect(`${config.TOPCODER_VALUES[config.TOPCODER_ENV].TC_LOGIN_URL}?retUrl=${encodeURIComponent(callbackUri)}`);
      });
    }
    if (!def.allowNormalUser) {
      actions.push((req, res, next) => {
        // check if any allowed role is matched with user's roles
        if (_(req.currentUser.roles).map((i) => i.toLowerCase())
          .intersection(_.map(config.ALLOWED_TOPCODER_ROLES, (j) => j.toLowerCase())).size() === 0) {
          const statusCode = 403;
          return res.status(statusCode).json({
            code: 'Forbidden',
            message: 'You are not allowed to access this resource.',
          });
        }
        return next();
      });
    }
    if (def.allowedRoles) {
      actions.push((req, res, next) => {
        // check if user has allowed roles
        if (_(req.currentUser.roles).map((i) => i.toLowerCase())
          .intersection(_.map(def.allowedRoles, (j) => j.toLowerCase())).size() === 0) {
          const statusCode = 403;
          return res.status(statusCode).json({
            code: 'Forbidden',
            message: 'You are not allowed to access this resource.',
          });
        }
        return next();
      });
    }
    actions.push(method);
    app[verb](`/api/${config.API_VERSION}${path}`, actions);
  });
});

app.get(`/api/${config.API_VERSION}/health`, getAppHealth);

// static content
app.use(express.static(Path.join(__dirname, 'public')));
app.use('*', (req, res) => {
  res.redirect('/');
});

// Error handler
app.use((err, req, res, next) => {
  if (res.headersSent) {
    next(err);
    return;
  }
  logger.logFullError(err, req.signature);
  let resultErr = err;
  if (err.isJoi) {
    resultErr = new errors.ValidationError('Invalid request parameters',
      _.map(err.details, (detail) => ({ message: detail.message, path: detail.path })));
  }
  // from express-jwt
  if (err.name === 'UnauthorizedError') {
    err.statusCode = 401; // eslint-disable-line no-magic-numbers
  }

  const resObj = { message: resultErr.message };
  if (resultErr.code) {
    resObj.code = resultErr.code;
  }
  if (resultErr.details) {
    resObj.details = resultErr.details;
  }
  res.status(resultErr.statusCode || 500).json(resObj); // eslint-disable-line no-magic-numbers
});

process.on('uncaughtException', (err) => {
  // Check if error related to Dynamodb conn
  if (err.code === 'NetworkingError' && err.region) {
    logger.error('DynamoDB connection failed.');
  }
  logger.logFullError(err, 'system');
});

// handle and log unhanled rejection
process.on('unhandledRejection', (err) => {
  logger.logFullError(err, 'system');
});

const port = config.PORT;
app.listen(port, '0.0.0.0');
logger.info('Topcoder X server listening on port %d', port);

module.exports = app;