payment api

app/controllers/api/discounts_controller.rb

@@ -0,0 +1,19 @@
+class Api::DiscountsController < ActionController::API
+  def  create
+    @invoice = Sale.find(params[:invoice_id])
+  end
+
+  #Update sale item - Price | Qty |
+  def update
+  end
+
+  #destroy - Remove items form invoice
+  def destroy
+    @sale.remove_item(params[:sale_item_id])
+  end
+
+  private
+  def set_invoice_params
+    @sale = Sale.find(params[:invoice_id])
+  end
+end