zephinzer/annams

const express = require('express');

const config = require('../../config')();

const readiness = require('./controller');
const utility = require('../utility');

module.exports = readinessRouteHandler;

/**
 * Factory function for an express.Router that handles the readiness check.
 *
 * @param {String} options.endpointPath
 * @param {String} options.basicAuthUsername
 * @param {String} options.basicAuthPassword
 * @param {Object} options
 *
 * @return {express.Router}
 */
function readinessRouteHandler({
  endpointPath = config.endpoint.ready,
  basicAuthUsername = config.authn.healthcheck.username,
  basicAuthPassword = config.authn.healthcheck.password,
} = {}) {
  const readinessRoute = new express.Router();
  readinessRoute.get(
    endpointPath,
    utility.basicAuth(basicAuthUsername, basicAuthPassword),
    readinessRouteHandler.createMiddleware(readiness)
  );
  return readinessRoute;
};

readinessRouteHandler.createMiddleware = (readiness) => (
  async (req, res) => {
    const status = await readiness.getStatus();
    (!status) && console.error(readiness.error);
    const alerts = Object.keys(readiness.warning).reduce((prev, curr) => {
      return (readiness.warning[curr]) ?
        Object.assign(prev, {[curr]: readiness.warning[curr]})
        : prev;
    }, {});
    console.error(alerts);
    const hasAlerts = Object.keys(alerts).length > 0;
    res
      .type('application/json')
      .status(status ? 200 : 503)
      .json(status ?
        (hasAlerts ? alerts :'ok')
        : readinessRouteHandler.createErrorResponse(readiness)
      );
  }
);

readinessRouteHandler.createErrorResponse = (readiness) => ({
  database: {
    status: readiness.status.database,
    data: readiness.error.database,
  },
  cache: {
    status: readiness.status.cache,
    data: readiness.error.cache,
  },
  pushGateway: {
    status: readiness.status.pushGateway,
    data: readiness.warning.pushGateway,
  },
});