Add product category importer

app/services/product_categories_importer.rb

@@ -0,0 +1,68 @@
+class ProductCategoriesImporter
+  attr_reader :errors, :supplier, :skipped
+
+  def initialize(supplier)
+    @errors = Errors.new
+    @errors.importer = self
+    @supplier = supplier
+  end
+
+  def import(string)
+    h = YAML.load(string) rescue nil
+    return errors.add 'cannot_parse_yaml' unless h
+    return errors.add 'no_product_categories' unless h["product_categories"].is_a?(Array)
+    categories = supplier.product_categories
+    existing_products = supplier.products
+    @skipped = []
+    h["product_categories"].each do |product_category_spec|
+      skipped << {reason: 'empty_name', type: 'product_category'} and next unless product_category_spec['name'].present?
+      unless existing_category = categories.find{|pc| pc.name == product_category_spec['name']}
+        existing_category = ProductCategory.new
+        product_category_spec.each do |attribute, value|
+          existing_category.public_send "#{attribute}=", value if existing_category.respond_to? "#{attribute}="
+        end
+      end
+      existing_category.supplier = supplier # hard coded security
+      if existing_category.valid?
+        (product_category_spec['products'] || []).each do |product_spec|
+          skipped << {reason: 'empty_name', type: 'product'} and next unless product_spec['name'].present?
+
+          unless  existing_product = existing_products.find{|ep| ep.name == product_spec['name']}
+            existing_product = Product.new
+          end
+          product_spec.each do |product_attribute, product_value|
+            existing_product.public_send "#{product_attribute}=", product_value if existing_product.respond_to? "#{product_attribute}="
+          end
+
+          existing_product.supplier = supplier
+          if existing_product.save
+            existing_category.product_ids |= [existing_product.id]
+          else
+            skipped << {reason: 'could_not_save', type: 'product'}
+          end
+
+        end
+        existing_category.save
+      else
+        skipped << {reason: 'could_not_save', type: 'product_category'}
+      end
+    end
+    self
+  end
+
+  def success?
+    errors.empty?
+  end
+
+  class Errors < Hash
+    attr_accessor :importer
+    def add(message)
+      self[:message] = message
+      importer
+    end
+
+    def message
+      self[:message]
+    end
+  end
+end