feat: Generic OAuth2 authentication implementation (#3094)

* OAuth2 authentication implementation

This PR shoul fix #2392. Used `passport-oauth2` strategy.

* indentations cleanup

* cleanup code

server/modules/authentication/oauth2/authentication.js

@@ -0,0 +1,54 @@
+const _ = require('lodash')
+
+/* global WIKI */
+
+// ------------------------------------
+// OAuth2 Connect Account
+// ------------------------------------
+
+const OAuth2Strategy = require('passport-oauth2').Strategy
+
+module.exports = {
+  init (passport, conf) {
+    var client = new OAuth2Strategy({
+      authorizationURL: conf.authorizationURL,
+      tokenURL: conf.tokenURL,
+      clientID: conf.clientId,
+      clientSecret: conf.clientSecret,
+      userInfoURL: conf.userInfoURL,
+      callbackURL: conf.callbackURL,
+      passReqToCallback: true,
+    }, async (req, accessToken, refreshToken, profile, cb) => {
+      try {
+        const user = await WIKI.models.users.processProfile({
+          providerKey: req.params.strategy,
+          profile: {
+            ...profile,
+            id: _.get(profile, conf.userId),
+            displayName: _.get(profile, conf.displayName, ''),
+            email: _.get(profile, conf.emailClaim)
+          }
+        })
+        cb(null, user)
+      } catch (err) {
+        cb(err, null)
+      }
+    })
+
+    client.userProfile = function (accesstoken, done) {
+      this._oauth2._useAuthorizationHeaderForGET = true;
+      this._oauth2.get(conf.userInfoURL, accesstoken, (err, data) => {
+        if (err) {
+          return done(err)
+        }
+        try {
+          data = JSON.parse(data)
+        } catch(e) {
+          return done(e)
+        }
+        done(null, data)
+      })
+    }
+    passport.use('oauth2', client)
+  }
+}