refactor(app.js, auth.js): Extract all auth method to individual modules

lib/web/auth/utils.js

@@ -0,0 +1,53 @@
+'use strict'
+
+const models = require('../../models')
+const config = require('../../config')
+const logger = require('../../logger')
+
+exports.setReturnToFromReferer = function setReturnToFromReferer (req) {
+  var referer = req.get('referer')
+  if (!req.session) req.session = {}
+  req.session.returnTo = referer
+}
+
+exports.passportGeneralCallback = function callback (accessToken, refreshToken, profile, done) {
+  var stringifiedProfile = JSON.stringify(profile)
+  models.User.findOrCreate({
+    where: {
+      profileid: profile.id.toString()
+    },
+    defaults: {
+      profile: stringifiedProfile,
+      accessToken: accessToken,
+      refreshToken: refreshToken
+    }
+  }).spread(function (user, created) {
+    if (user) {
+      var needSave = false
+      if (user.profile !== stringifiedProfile) {
+        user.profile = stringifiedProfile
+        needSave = true
+      }
+      if (user.accessToken !== accessToken) {
+        user.accessToken = accessToken
+        needSave = true
+      }
+      if (user.refreshToken !== refreshToken) {
+        user.refreshToken = refreshToken
+        needSave = true
+      }
+      if (needSave) {
+        user.save().then(function () {
+          if (config.debug) { logger.info('user login: ' + user.id) }
+          return done(null, user)
+        })
+      } else {
+        if (config.debug) { logger.info('user login: ' + user.id) }
+        return done(null, user)
+      }
+    }
+  }).catch(function (err) {
+    logger.error('auth callback failed: ' + err)
+    return done(err, null)
+  })
+}