middlewares.js

const q = require('q');
const uuid = require('uuid');
const winston = require('winston');
const apiTracker = require('./database-connect/apiTracker');
const utilHelper = require('./helpers/util');
const sessionHelper = require('./helpers/session');
const appService = require('./services/app');


function ignoreUrl(requestUrl) {
  try {
    const ignoreUrls = [ // for the routes to check whether the particular service is active/not
      '/api/userService',
      '/api/customService',
      '/api/roleService',
      '/api/status',
      '/file',
      '/api/createIndex',
      '/pages',
      '/status',
    ];

    for (let i = 0; i < ignoreUrls.length; i++) {
      if (requestUrl.indexOf(ignoreUrls[i]) >= 0) {
        return true;
      }
    }
    return false;
  } catch (err) {
    winston.log('error', {
      error: String(err),
      stack: new Error().stack,
    });
    throw err;
  }
}

function _setSession(req, res) {
  try {
    if (!req.session) {
      req.session = {};
      req.session.id = uuid.v1();
    }

    res.header('sessionID', req.session.id);

    const obj = {
      id: req.session.id,
      userId: null,
      loggedIn: false,
      appId: null,
      email: null,
      roles: null,
    };

    req.session = obj;
    const expireDays = 30; // Default
    sessionHelper.saveSession(obj, expireDays);
  } catch (err) {
    winston.log('error', {
      error: String(err),
      stack: new Error().stack,
    });
  }
}

module.exports = (app) => {
  app.use((req, res, next) => {
    if (req.is('text/*')) {
      req.text = '';
      req.setEncoding('utf8');
      req.on('data', (chunk) => {
        req.text += chunk;
      });
      req.on('end', next);
    } else {
      next();
    }
  });

  // This middleware converts text to JSON.
  app.use((req, res, next) => {
    try {
      if (req.text && utilHelper._isJSON(req.text)) {
        req.body = JSON.parse(req.text);
      }

      if (req.body && typeof (req.body) === 'string' && utilHelper._isJSON(req.body)) {
        req.body = JSON.parse(req.body);
      }

      // INVALIDATE CACHE FOR API
      res.setHeader('Cache-Control', 'no-cache, no-store, must-revalidate'); // HTTP 1.1.
      res.setHeader('Pragma', 'no-cache'); // HTTP 1.0.
      res.setHeader('Expires', '0'); // Proxies.

      next();
    } catch (e) {
      winston.log('error', {
        error: String(e),
        stack: new Error().stack,
      });
      // cannot convert to JSON.
      next();
    }
  });

  app.use([
    '/file/:appId',
    '/data/:appId',
    '/app/:appId/:tableName',
    '/user/:appId',
  ], (req, res, next) => {
    // This is the Middleware for authenticating the app access using appID and key
    // check if all the services are loaded first.

    try {
      if (req.text && utilHelper._isJSON(req.text)) {
        req.body = JSON.parse(req.text);
      }

      if (req.body && typeof (req.body) === 'string' && utilHelper._isJSON(req.body)) {
        req.body = JSON.parse(req.body);
      }

      const requestRecvd = req.originalUrl; // this is the relative url.
      if (ignoreUrl(requestRecvd)) {
        next();
      } else {
        const appKey = req.body.key || req.params.key; // key is extracted from body/url parameters

        const { appId } = req.params;
        if (!appKey) {
          res.status(401).send({
            status: 'error',
            // eslint-disable-next-line max-len
            message: "Key not found. You need to have your Client Key or Master Key in the body or url parameter 'key' when you make this request",
          });
        }

        // check if app is in the plan.
        const promises = [];
        promises.push(apiTracker.isInPlanLimit(appId));
        promises.push(appService.isKeyValid(appId, appKey));
        q.all(promises).then((result) => {
          const isAppKeyValid = result[1];
          const isInPlan = result[0];
          if (!isInPlan) {
            // check if the appIsReleased.
            apiTracker.log(appId, 'isReleased/isReleased', '', 'JavaScript', true);
            res.status(402).send('Reached Plan Limit. Upgrade Plan.');
          } else if (!isAppKeyValid) {
            res.status(401).send('App ID or App Key is invalid.');
          } else {
            next();
          }
        }, err => res.status(500).send(err.message));
      }
    } catch (err) {
      winston.log('error', {
        error: String(err),
        stack: new Error().stack,
      });
    }
  });

  app.use((req, res, next) => {
    try {
      // Middleware for retrieving sessions

      res.header('Access-Control-Expose-Headers', 'sessionID');

      if (req.headers.sessionid) {
        res.header('sessionID', req.headers.sessionid);
        sessionHelper.getSession(req.headers.sessionid, (err, session) => {
          if (!err) {
            req.session = session;
            next();
          } else {
            req.session = {};
            req.session.id = req.header.sessionid;
            next();
          }
        });
      } else {
        _setSession(req, res);
        next();
      }
    } catch (err) {
      winston.log('error', {
        error: String(err),
        stack: new Error().stack,
      });
    }
  });
};