merge automatic group order invoice generation

see https://github.com/foodcoops/foodsoft/pull/907 for reference
and original work by viehlieb

Co-authored-by: viehlieb <pf@pragma-shift.net>

fix PDF Pdf

make explicit deposit in invoices work

add ordergroupname to invoice file name

mark bold sum for vat exempt foodcoops

download multiple group order invoice as zip

app/models/group_order_invoice.rb

@@ -0,0 +1,58 @@
+class GroupOrderInvoice < ApplicationRecord
+  belongs_to :group_order
+  validates_presence_of :group_order
+  validates_uniqueness_of :invoice_number
+  validate :tax_number_set
+  after_initialize :init, unless: :persisted?
+
+  def generate_invoice_number(count)
+    trailing_number = count.to_s.rjust(4, '0')
+    if GroupOrderInvoice.find_by(invoice_number: self.invoice_date.strftime("%Y%m%d") + trailing_number)
+      generate_invoice_number(count.to_i + 1)
+    else
+      self.invoice_date.strftime("%Y%m%d") + trailing_number
+    end
+  end
+
+  def tax_number_set
+    if FoodsoftConfig[:contact][:tax_number].blank?
+      errors.add(:group_order_invoice, "Keine Steuernummer in FoodsoftConfig :contact gesetzt")
+    end
+  end
+
+  def init
+    self.invoice_date = Time.now unless invoice_date
+    self.invoice_number = generate_invoice_number(1) unless self.invoice_number
+    self.payment_method = FoodsoftConfig[:group_order_invoices]&.[](:payment_method) || I18n.t('activerecord.attributes.group_order_invoice.payment_method') unless self.payment_method
+  end
+
+  def name
+    I18n.t('activerecord.attributes.group_order_invoice.name') + "_#{invoice_number}"
+  end
+
+  def load_data_for_invoice
+    invoice_data = {}
+    order = group_order.order
+    invoice_data[:supplier] = order.supplier.name
+    invoice_data[:ordergroup] = group_order.ordergroup
+    invoice_data[:group_order] = group_order
+    invoice_data[:invoice_number] = invoice_number
+    invoice_data[:invoice_date] = invoice_date
+    invoice_data[:tax_number] = FoodsoftConfig[:contact][:tax_number]
+    invoice_data[:payment_method] = payment_method
+    invoice_data[:order_articles] = {}
+    group_order.order_articles.each do |order_article|
+      # Get the result of last time ordering, if possible
+      goa = group_order.group_order_articles.detect { |tmp_goa| tmp_goa.order_article_id == order_article.id }
+
+      # Build hash with relevant data
+      invoice_data[:order_articles][order_article.id] = {
+        :price => order_article.article.fc_price,
+        :quantity => (goa ? goa.quantity : 0),
+        :total_price => (goa ? goa.total_price : 0),
+        :tax => order_article.article.tax
+      }
+    end
+    invoice_data
+  end
+end