Add needed quantities to existing line items

app/jobs/backorder_job.rb

@@ -4,10 +4,6 @@ class BackorderJob < ApplicationJob
   FDC_BASE_URL =  "https://env-0105831.jcloud-ver-jpe.ik-server.com/api/dfc/Enterprises/test-hodmedod"
   FDC_CATALOG_URL = "#{FDC_BASE_URL}/SuppliedProducts".freeze
   FDC_ORDERS_URL = "#{FDC_BASE_URL}/Orders".freeze
-  FDC_SALE_SESSION_URL = "#{FDC_BASE_URL}/SalesSession/#".freeze
-
-  # The FDC implementation needs special ids for new objects:
-  FDC_ORDER_LINES_URL = "#{FDC_ORDERS_URL}/#/OrderLines".freeze
 
   queue_as :default
 
@@ -35,17 +31,15 @@ class BackorderJob < ApplicationJob
     backorder = orderer.find_or_build_order(order)
     catalog = load_catalog(order.distributor.owner)
 
-    linked_variants.each_with_index do |variant, index|
+    linked_variants.each do |variant|
       needed_quantity = -1 * variant.on_hand
       offer = best_offer(catalog, variant)
 
-      # Order lines are enumerated in the FDC API:
-      line = build_order_line(offer, needed_quantity)
-      line.semanticId = "#{FDC_ORDER_LINES_URL}/#{index}"
-      backorder.lines << line
+      line = orderer.find_or_build_order_line(backorder, offer)
+      line.quantity = line.quantity.to_i + needed_quantity
     end
 
-    backorderer.send_order(order, backorder)
+    orderer.send_order(order, backorder)
 
     # Once we have transformations and know the quantities in bulk products
     # we will need to increase on_hand by the ordered quantity.
@@ -54,16 +48,6 @@ class BackorderJob < ApplicationJob
     end
   end
 
-  def self.build_order_line(offer, quantity)
-    OrderLineBuilder.build(offer, quantity)
-  end
-
-  def self.build_sale_session(order)
-    SaleSessionBuilder.build(order.order_cycle).tap do |session|
-      session.semanticId = FDC_SALE_SESSION_URL
-    end
-  end
-
   def self.best_offer(catalog, variant)
     link = variant.semantic_links[0]
 

app/services/fdc_backorderer.rb

@@ -5,6 +5,7 @@ class FdcBackorderer
   FDC_BASE_URL = "https://env-0105831.jcloud-ver-jpe.ik-server.com/api/dfc/Enterprises/test-hodmedod"
   FDC_ORDERS_URL = "#{FDC_BASE_URL}/Orders".freeze
   FDC_NEW_ORDER_URL = "#{FDC_ORDERS_URL}/#".freeze
+  FDC_SALE_SESSION_URL = "#{FDC_BASE_URL}/SalesSession/#".freeze
 
   def find_or_build_order(ofn_order)
     remote_order = find_open_order(ofn_order.distributor.owner)
@@ -44,6 +45,33 @@ class FdcBackorderer
     end
   end
 
+  def find_or_build_order_line(order, offer)
+    find_order_line(order, offer) || build_order_line(order, offer)
+  end
+
+  def build_order_line(order, offer)
+    # Order lines are enumerated in the FDC API and we must assign a unique
+    # semantic id. We need to look at current ids to avoid collisions.
+    # existing_ids = order.lines.map do |line|
+    #   line.semanticId.match(/[0-9]+$/).to_s.to_i
+    # end
+    # next_id = existing_ids.max.to_i + 1
+
+    # Suggested by FDC team:
+    next_id = order.lines.count + 1
+
+    OrderLineBuilder.build(offer, 0).tap do |line|
+      line.semanticId = "#{order.semanticId}/OrderLines/#{next_id}"
+      order.lines << line
+    end
+  end
+
+  def find_order_line(order, offer)
+    order.lines.find do |line|
+      line.offer.offeredItem.semanticId == offer.offeredItem.semanticId
+    end
+  end
+
   def import(user, url)
     api = DfcRequest.new(user)
     json = api.call(url)
@@ -54,17 +82,24 @@ class FdcBackorderer
     lines = backorder.lines
     offers = lines.map(&:offer)
     products = offers.map(&:offeredItem)
-    session = build_sale_session(ofn_order)
-    json = DfcIo.export(backorder, *lines, *offers, *products, session)
 
     api = DfcRequest.new(ofn_order.distributor.owner)
 
     if backorder.semanticId == FDC_NEW_ORDER_URL
       # Create order via POST:
+      session = build_sale_session(ofn_order)
+      json = DfcIo.export(backorder, *lines, *offers, *products, session)
       api.call(FDC_ORDERS_URL, json)
     else
       # Update existing:
-      api.call(backorder.semanticId, json)
+      json = DfcIo.export(backorder, *lines, *offers, *products)
+      api.call(backorder.semanticId, json, method: :put)
+    end
+  end
+
+  def build_sale_session(order)
+    SaleSessionBuilder.build(order.order_cycle).tap do |session|
+      session.semanticId = FDC_SALE_SESSION_URL
     end
   end
 end

engines/dfc_provider/app/services/dfc_request.rb

@@ -13,15 +13,15 @@ class DfcRequest
     @user = user
   end
 
-  def call(url, data = nil)
+  def call(url, data = nil, method: nil)
     begin
-      response = request(url, data)
+      response = request(url, data, method:)
     rescue Faraday::UnauthorizedError, Faraday::ForbiddenError
       raise unless token_stale?
 
       # If access was denied and our token is stale then refresh and retry:
       refresh_access_token!
-      response = request(url, data)
+      response = request(url, data, method:)
     end
 
     response.body
@@ -29,9 +29,11 @@ class DfcRequest
 
   private
 
-  def request(url, data = nil)
+  def request(url, data = nil, method: nil)
     only_public_connections do
-      if data
+      if method == :put
+        connection.put(url, data)
+      elsif data
         connection.post(url, data)
       else
         connection.get(url)

spec/jobs/backorder_job_spec.rb

@@ -31,6 +31,8 @@ RSpec.describe BackorderJob do
         semantic_id: product_link
       )
       BackorderJob.check_stock(order)
+
+      expect(variant.on_hand).to eq 0
     end
   end
 

spec/services/fdc_backorderer_spec.rb

@@ -35,4 +35,33 @@ RSpec.describe FdcBackorderer do
       expect(backorder.lines.count).to eq 1
     end
   end
+
+  describe "#find_or_build_order_line" do
+    it "add quantity to an existing line item", vcr: true do
+      catalog = BackorderJob.load_catalog(order.distributor.owner)
+      backorder = subject.find_or_build_order(order)
+      existing_line = backorder.lines[0]
+
+      # The FDC API returns different ids for the same offer.
+      # In order to test that we can still match it, we are retrieving
+      # the catalog offer here which is different to the offer on the
+      # existing order line.
+      ordered_product = existing_line.offer.offeredItem
+      catalog_product = catalog.find do |i|
+        i.semanticId == ordered_product.semanticId
+      end
+      catalog_offer = BackorderJob.offer_of(catalog_product)
+
+      # The API response is missing this connection:
+      catalog_offer.offeredItem = catalog_product
+
+      # Just confirm that we got good test data from the API:
+      expect(backorder.semanticId).to match %r{^https.*/[0-9]+$}
+      expect(backorder.lines.count).to eq 1
+
+      found_line = subject.find_or_build_order_line(backorder, catalog_offer)
+
+      expect(found_line).to eq existing_line
+    end
+  end
 end