first commit

app/middlewares/user.js

@@ -0,0 +1,38 @@
+'use strict';
+
+const CdbRequest = require('../models/cartodb_request');
+
+module.exports = function user(metadataBackend) {
+    const cdbRequest = new CdbRequest();
+
+    return function userMiddleware (req, res, next) {
+        res.locals.user = getUserNameFromRequest(req, cdbRequest);
+
+        checkUserExists(metadataBackend, res.locals.user, function(err, userExists) {
+            if (err || !userExists) {
+                const error = new Error('Unauthorized');
+                error.type = 'auth';
+                error.subtype = 'user-not-found';
+                error.http_status = 404;
+                error.message = errorUserNotFoundMessageTemplate(res.locals.user);
+                next(error);
+            }
+
+            return next();
+        });
+    };
+};
+
+function getUserNameFromRequest(req, cdbRequest) {
+    return cdbRequest.userByReq(req);
+}
+
+function checkUserExists(metadataBackend, userName, callback) {
+    metadataBackend.getUserId(userName, function(err) {
+        callback(err, !err);
+    });
+}
+
+function errorUserNotFoundMessageTemplate(user) {
+    return `Sorry, we can't find CARTO user '${user}'. Please check that you have entered the correct domain.`;
+}