make login page date different depending on auth type

auth/token.go

@@ -1 +1,32 @@
 package auth
+
+import (
+	"encoding/json"
+	"os"
+
+	"golang.org/x/oauth2"
+)
+
+type TokenStore struct {
+	filePath string
+}
+
+func (ts *TokenStore) Save(token *oauth2.Token) error {
+	data, err := json.Marshal(token)
+	if err != nil {
+		return err
+	}
+	return os.WriteFile(ts.filePath, data, 0600)
+}
+
+func (ts *TokenStore) Load() (*oauth2.Token, error) {
+	data, err := os.ReadFile(ts.filePath)
+	if err != nil {
+		return nil, err
+	}
+	var token oauth2.Token
+	if err := json.Unmarshal(data, &token); err != nil {
+		return nil, err
+	}
+	return &token, nil
+}