add cancan for authorization

app/controllers/users_controller.rb

@@ -1,26 +1,20 @@
 # frozen_string_literal: true
 
 class UsersController < ApplicationController
-  before_action :load_user, only: %i[edit update destroy]
+  load_and_authorize_resource :user, only: %i[index edit new update destroy]
+
+  before_action :build_user, only: :create
+  authorize_resource :user, only: :create
 
   def index
-    @pagy, @users = pagy(current_account.users.active.order(id: :desc))
+    @pagy, @users = pagy(@users.active.order(id: :desc))
   end
 
-  def new
-    @user = current_account.users.new
-  end
+  def new; end
 
   def edit; end
 
   def create
-    @user = current_account.users.find_by(email: user_params[:email])&.tap do |user|
-      user.assign_attributes(user_params)
-      user.deleted_at = nil
-    end
-
-    @user ||= current_account.users.new(user_params)
-
     if @user.save
       UserMailer.invitation_email(@user).deliver_later!
 
@@ -33,7 +27,7 @@ class UsersController < ApplicationController
   def update
     return redirect_to settings_users_path, notice: 'Unable to update user.' if Docuseal.demo?
 
-    if @user.update(user_params.compact_blank)
+    if @user.update(user_params.compact_blank.except(current_user == @user ? :role : nil))
       redirect_to settings_users_path, notice: 'User has been updated'
     else
       render turbo_stream: turbo_stream.replace(:modal, template: 'users/edit'), status: :unprocessable_entity
@@ -52,11 +46,18 @@ class UsersController < ApplicationController
 
   private
 
-  def load_user
-    @user = current_account.users.find(params[:id])
+  def build_user
+    @user = current_account.users.find_by(email: user_params[:email])&.tap do |user|
+      user.assign_attributes(user_params)
+      user.deleted_at = nil
+    end
+
+    @user ||= current_account.users.new(user_params)
+
+    @user
   end
 
   def user_params
-    params.require(:user).permit(:email, :first_name, :last_name, :password)
+    params.require(:user).permit(:email, :first_name, :last_name, :password, :role)
   end
 end