change all sale item

app/models/sale_item.rb

@@ -14,19 +14,42 @@ class SaleItem < ApplicationRecord
   # Add Sale Items
   def self.add_sale_items(sale_items)
     sale_items.each do|saleitemObj|
-      saleitemObj.remark = 'foc'
-      saleitemObj.save
       @newsaleitem = SaleItem.new
       @newsaleitem = saleitemObj.dup
       @newsaleitem.save
-      @newsaleitem.qty = saleitemObj.qty * -1
-      @newsaleitem.price = saleitemObj.price * -1
-      @newsaleitem.is_taxable = 1
+      @newsaleitem.qty = saleitemObj.qty * -1      
+      @newsaleitem.unit_price = saleitemObj.unit_price * -1
+      @newsaleitem.taxable_price = (saleitemObj.unit_price * saleitemObj.qty) * -1
+      @newsaleitem.price = (saleitemObj.unit_price * saleitemObj.qty) * -1      
       @newsaleitem.product_name = saleitemObj.product_name + ' (FOC)'
       @newsaleitem.save
     end    
   end
 
+  def self.update_existing_item(qty, item, sale_id, type, item_price)
+    sale_item = SaleItem.new
+    sale_item.product_code = item.item_code
+    sale_item.product_name = item.item_name + "(#{type})"
+    sale_item.product_alt_name = item.alt_name
+    sale_item.account_id = item.account_id
+    sale_item.remark = type
+    if type == "foc" || type == "promotion" || type == "void"
+      sale_item.qty = qty * (-1)
+    else
+      sale_item.qty = qty
+    end
+
+    sale_item.unit_price = item_price # * (-1)
+    sale_item.taxable_price = (qty * item_price) * (-1)
+    sale_item.price = (qty * item_price) * (-1)
+
+    sale_item.is_taxable = 1
+    sale_item.sale_id = sale_id
+    sale_item.save
+    sale =  Sale.find(sale_id)
+    sale.compute_by_sale_items(sale.id, sale.sale_items, sale.total_discount)
+  end
+
   def self.get_order_items_details(sale_id)
     order_details = SaleItem.select("sales.total_tax as tax_amount, sales.grand_total as grand_total_amount , sales.total_discount as discount_amount,sales.receipt_date as receipt_date,
                       sales.cashier_name,sales.receipt_no,sale_items.product_name as item_name,sale_items.qty,sale_items.price,sale_items.unit_price as total_price")