// Copyright IBM Corp. 2014,2016. All Rights Reserved.
  // Node module: loopback-context-cls
  // This file is licensed under the MIT License.
  // License text available at https://opensource.org/licenses/MIT
  
  'use strict';
  
  var LoopBackContext = require('../current-context');
  
  module.exports = perRequestContextFactory;
  
  var name = 'loopback';
  
  /**
   * Context middleware.
   * ```js
   * var perRequestContext = require(
   *   'loopback-context/server/middleware/per-request-context.js');
   * var app = loopback();
   * app.use(perRequestContext(options);
   * app.use(loopback.rest());
   * app.listen();
   * ```
   * @options {Object} [options] Options for context
   * @property {String} name Context scope name.
   * @property {Boolean} enableHttpContext Whether HTTP context is enabled. Default is false.
   */
  
  function perRequestContextFactory(options) {
    options = options || {};
    var scope = options.name || name;
    var enableHttpContext = options.enableHttpContext || false;
    var ns = LoopBackContext.createContext(scope);
  
    // Return the middleware
    return function perRequestContext(req, res, next) {
      if (req.loopbackContext) {
        return next();
      }
  
      LoopBackContext.runInContext(function processRequestInContext(ns, domain) {
        req.loopbackContext = ns;
  
        // Bind req/res event emitters to the given namespace
        ns.bindEmitter(req);
        ns.bindEmitter(res);
  
        // Add req/res event emitters to the current domain
        domain.add(req);
        domain.add(res);
  
        // Run the code in the context of the namespace
        if (enableHttpContext) {
          // Set up the transport context
          ns.set('http', {req: req, res: res});
        }
        next();
      });
    };
  }