From 6dc3fd0f45d9a06bb1aaa65dbdcf08701eca45a1 Mon Sep 17 00:00:00 2001
From: Yang Luo <hsluoyz@qq.com>
Date: Fri, 18 Jun 2021 23:25:24 +0800
Subject: [PATCH] Avoid linking the same account twice.

---
 controllers/auth.go | 11 +++++++++++
 object/user_util.go |  4 ++++
 2 files changed, 15 insertions(+)

diff --git a/controllers/auth.go b/controllers/auth.go
index 1647e318..9df14fb7 100644
--- a/controllers/auth.go
+++ b/controllers/auth.go
@@ -304,6 +304,17 @@ func (c *ApiController) Login() {
 				return
 			}
 
+			oldUser := object.GetUserByField(application.Organization, provider.Type, userInfo.Id)
+			if oldUser == nil {
+				oldUser = object.GetUserByField(application.Organization, provider.Type, userInfo.Username)
+			}
+			if oldUser != nil {
+				resp = &Response{Status: "error", Msg: fmt.Sprintf("The account for provider: %s and username: %s (%s) is already linked to another account", provider.Type, userInfo.Username, userInfo.DisplayName)}
+				c.Data["json"] = resp
+				c.ServeJSON()
+				return
+			}
+
 			user := object.GetUser(userId)
 
 			// sync info from 3rd-party if possible
diff --git a/object/user_util.go b/object/user_util.go
index 5d1c5217..54956eca 100644
--- a/object/user_util.go
+++ b/object/user_util.go
@@ -24,6 +24,10 @@ import (
 )
 
 func GetUserByField(organizationName string, field string, value string) *User {
+	if field == "" || value == "" {
+		return nil
+	}
+
 	user := User{Owner: organizationName}
 	existed, err := adapter.Engine.Where(fmt.Sprintf("%s=?", field), value).Get(&user)
 	if err != nil {