From 1880b300291c8574998952cad59ccd579e5fe3ea Mon Sep 17 00:00:00 2001
From: "Lin, Hung-Shin" <wancat@wancat.cc>
Date: Thu, 5 Oct 2023 11:50:00 +0800
Subject: [PATCH] feat: use google to login

---
 server/src/auth/googleStrategy.js | 34 ++++++++++++++++++++++++++++++-
 server/src/models/user.js         |  7 ++++++-
 2 files changed, 39 insertions(+), 2 deletions(-)

diff --git a/server/src/auth/googleStrategy.js b/server/src/auth/googleStrategy.js
index c126893..f901c43 100644
--- a/server/src/auth/googleStrategy.js
+++ b/server/src/auth/googleStrategy.js
@@ -1,6 +1,7 @@
 import GoogleStrategy from 'passport-google-oidc'
 
 import config from '../config.js'
+import User from '../models/user.js'
 
 console.log('Google config:', config.google)
 
@@ -13,6 +14,37 @@ export default new GoogleStrategy(
   },
   function verify(issuer, profile, cb) {
     console.log('Get a google login:', profile)
-    return cb(null, profile)
+
+    process.nextTick(async () => {
+      const email = profile.emails[0]?.value
+      if (!email) {
+        cb(new Error('No email found'))
+        return
+      }
+
+      let user = await User.findOne({ 'google.id': profile.id })
+      if (!user) {
+        user = await User.findOne({ email })
+        const google = {
+          id: profile.id,
+          displayName: profile.displayName,
+        }
+        console.log('Existing user:', user)
+        if (!user) {
+          user = new User({
+            email,
+            google,
+          })
+        } else if (user.google?.id) {
+          cb(new Error('Email already used and binded to another account'))
+          return
+        } else {
+          user.google = google
+        }
+        await user.save()
+      }
+
+      cb(null, user)
+    })
   }
 )
diff --git a/server/src/models/user.js b/server/src/models/user.js
index 5899e90..1c3b891 100644
--- a/server/src/models/user.js
+++ b/server/src/models/user.js
@@ -4,7 +4,8 @@ const User = model('User', {
   username: {
     type: String,
     unique: true,
-    required: true,
+    required: false, // should be required,
+    // but need to let social login users to pick one after login
   },
   email: {
     type: String,
@@ -12,6 +13,10 @@ const User = model('User', {
     required: true,
   },
   hashedPassword: String,
+  google: {
+    id: String,
+    displayName: String,
+  },
 })
 
 export default User