Add expected_amount to Invoice

expected_amount returns the sum of all associated orders together with
the transport costs.

app/models/invoice.rb

@@ -41,6 +41,24 @@ class Invoice < ApplicationRecord
     amount - deposit + deposit_credit
   end
 
+  def orders_sum
+    orders
+      .joins(order_articles: [:article_price])
+      .sum("COALESCE(order_articles.units_received, order_articles.units_billed, order_articles.units_to_order)" \
+        + "* article_prices.unit_quantity" \
+        + "* ROUND((article_prices.price + article_prices.deposit) * (100 + article_prices.tax) / 100, 2)")
+  end
+
+  def orders_transport_sum
+    orders.sum(:transport)
+  end
+
+  def expected_amount
+    return net_amount unless orders.any?
+
+    orders_sum + orders_transport_sum
+  end
+
   protected
 
   def valid_attachment

app/views/finance/invoices/show.html.haml

@@ -29,10 +29,14 @@
         %dd><
           - @invoice.orders.order(:ends).each_with_index do |order, index|
             - sum = order.sum
-            - total += sum
+            - transport = order.transport || 0
+            - total += sum + transport
             = ', ' if index > 0
             = link_to format_date(order.ends), new_finance_order_path(order_id: order)
-            = ' (' + number_to_currency(sum) + ')'
+            = ' (' + number_to_currency(sum)
+            - if transport != 0
+              = ' + ' + number_to_currency(transport)
+            = ')'
 
       %dt= heading_helper(Invoice, :number) + ':'
       %dd= @invoice.number

app/views/finance/invoices/unpaid.html.haml

@@ -8,12 +8,17 @@
     - invoices_text = []
     %p
     - for invoice in invoices
+      - invoice_amount_diff = invoice.expected_amount - invoice.net_amount
       - invoices_sum += invoice.amount
       - invoices_text << invoice.number
       = link_to finance_invoice_path(invoice) do
         = format_date invoice.date
         = ' ' + invoice.number
       = ' ' + number_to_currency(invoice.amount)
+      - if invoice_amount_diff != 0
+        %span{style: "color:#{invoice_amount_diff < 0 ? 'red' : 'green'}"}
+          = invoice_amount_diff > 0 ? '+' : '-'
+          = number_to_currency(invoice_amount_diff.abs)
       - if invoice.attachment_data?
         = link_to finance_invoice_attachment_path(invoice) do
           = glyph :download

lib/invoices_csv.rb

@@ -11,6 +11,7 @@ class InvoicesCsv < RenderCSV
       Invoice.human_attribute_name(:supplier),
       Invoice.human_attribute_name(:number),
       Invoice.human_attribute_name(:amount),
+      Invoice.human_attribute_name(:total),
       Invoice.human_attribute_name(:deposit),
       Invoice.human_attribute_name(:deposit_credit),
       Invoice.human_attribute_name(:paid_on),
@@ -27,6 +28,7 @@ class InvoicesCsv < RenderCSV
         t.supplier.name,
         t.number,
         t.amount,
+        t.expected_amount,
         t.deposit,
         t.deposit_credit,
         t.paid_on,