Add button to easily upgrade user promo

ui/src/lib/users.js

@@ -16,10 +16,45 @@ export async function getUsers() {
   }
 }
 
+export class User {
+  constructor(res) {
+    if (res) {
+      this.update(res);
+    }
+  }
+
+  update({ id, login, email, firstname, lastname, time, promo, groups, is_admin }) {
+    this.id = id;
+    this.login = login;
+    this.email = email;
+    this.firstname = firstname;
+    this.lastname = lastname;
+    this.time = time;
+    this.promo = promo;
+    this.groups = groups;
+    this.is_admin = is_admin;
+  }
+
+  async save() {
+    const res = await fetch(this.id?`api/users/${this.id}`:'api/users', {
+      method: this.id?'PUT':'POST',
+      headers: {'Accept': 'application/json'},
+      body: JSON.stringify(this),
+    });
+    if (res.status == 200) {
+      const data = await res.json()
+      this.update(data);
+      return data;
+    } else {
+      throw new Error((await res.json()).errmsg);
+    }
+  }
+}
+
 export async function getUser(uid) {
   const res = await fetch(`api/users/${uid}`, {headers: {'Accept': 'application/json'}})
   if (res.status == 200) {
-    return await res.json();
+    return new User(await res.json());
   } else {
     throw new Error((await res.json()).errmsg);
   }