On #47 Adapt unit ratio export/import to be interpreted as a conversi…

…on chain instead of a conversion table

app/lib/articles_csv.rb

@@ -44,13 +44,20 @@ def data
         article.minimum_order_quantity,
         ArticleUnitsLib.get_translated_name_for_code(article.billing_unit),
         article.article_category.try(:name),
-        article.article_unit_ratios.map do |ratio|
-          "#{ratio.quantity} #{escape_csv_ratio(ArticleUnitsLib.get_translated_name_for_code(ratio.unit))}"
-        end.join(', ')
+        get_csv_ratios(article)
       ]
     end
   end
 
+  def get_csv_ratios(article)
+    previous_quantity = nil
+    article.article_unit_ratios.each_with_index.map do |ratio, _index|
+      quantity = previous_quantity.nil? ? ratio.quantity : ratio.quantity / previous_quantity
+      previous_quantity = ratio.quantity
+      "#{quantity} #{escape_csv_ratio(ArticleUnitsLib.get_translated_name_for_code(ratio.unit))}"
+    end.join(', ')
+  end
+
   def escape_csv_ratio(str)
     str.gsub('\\', '\\\\').gsub(',', '\\,')
   end

app/lib/foodsoft_file.rb

@@ -35,11 +35,15 @@ def self.parse(file, options = {})
   def self.parse_ratios_cell(ratios_cell)
     return [] if ratios_cell.blank?
 
+    previous_quantity = nil
     ratios = ratios_cell.split(/(?<!\\), /).each_with_index.map do |ratio_str, index|
       md = ratio_str.gsub('\\\\', '\\').gsub('\\,', ',').match(/(?<quantity>[+-]?(?:[0-9]*[.])?[0-9]+) (?<unit_name>.*)/)
+      quantity = md[:quantity].to_d
+      calculated_quantity = previous_quantity.nil? ? quantity : quantity * previous_quantity
+      previous_quantity = calculated_quantity
       {
         sort: index + 1,
-        quantity: md[:quantity],
+        quantity: calculated_quantity,
         unit: ArticleUnitsLib.get_code_for_unit_name(md[:unit_name])
       }
     end