fetch client id from server for oauth

client/app/services/oauth.service.ts

@@ -0,0 +1,18 @@
+import { axios } from './axios.service';
+
+const redirectUrl = window.location.origin + '/oauth';
+
+const getClientID = async (): Promise<string> => {
+  const res = await axios.get('/api/config/client_id');
+  return res.data['id'];
+};
+
+const getOauthUrl = async (): Promise<string> => {
+  const clientID = await getClientID();
+  return `https://discordapp.com/api/oauth2/authorize?client_id=${clientID}&redirect_uri=${redirectUrl}&response_type=code&scope=email%20identify`;
+};
+
+export const OauthService = {
+  getClientID,
+  getOauthUrl,
+};