Route: Add `#calculate_costs!` to populate `#costs` with `WayCost`s

This new method will launch a worker that takes the route's `StopArea`s,
converts them to `WayCost`s, sends them to the TomTom API to calculate
distance and time costs, and saves those costs to the route's `costs`
field.

Refs #6095

4 files changed, 55 insertions, 0 deletions

diff --git a/app/models/chouette/route.rb b/app/models/chouette/route.rb
index d0d776bc6..a1d44f53f 100644
--- a/app/models/chouette/route.rb
+++ b/app/models/chouette/route.rb
@@ -188,6 +188,10 @@ module Chouette
       journey_pattern
     end
 
+    def calculate_costs!
+      RouteWayCostWorker.perform_async(id)
+    end
+
     protected
 
     def self.vehicle_journeys_timeless(stop_point_id)
diff --git a/app/services/route_way_cost_calculator.rb b/app/services/route_way_cost_calculator.rb
new file mode 100644
index 000000000..2e30c94fc
--- /dev/null
+++ b/app/services/route_way_cost_calculator.rb
@@ -0,0 +1,12 @@
+class RouteWayCostCalculator
+  def initialize(route)
+    @route = route
+  end
+
+  def calculate!
+    way_costs = StopAreasToWayCostsConverter.new(@route.stop_areas).convert
+    way_costs = TomTom.batch(way_costs)
+    way_costs = WayCostCollectionJSONSerializer.dump(way_costs)
+    @route.update(costs: way_costs)
+  end
+end
diff --git a/app/workers/route_way_cost_worker.rb b/app/workers/route_way_cost_worker.rb
new file mode 100644
index 000000000..adb10957b
--- /dev/null
+++ b/app/workers/route_way_cost_worker.rb
@@ -0,0 +1,8 @@
+class RouteWayCostWorker
+  include Sidekiq::Worker
+
+  def perform(route_id)
+    route = Chouette::Route.find(route_id)
+    RouteWayCostCalculator.new(route).calculate!
+  end
+end
diff --git a/spec/services/route_way_cost_calculator_spec.rb b/spec/services/route_way_cost_calculator_spec.rb
new file mode 100644
index 000000000..d5358fcf6
--- /dev/null
+++ b/spec/services/route_way_cost_calculator_spec.rb
@@ -0,0 +1,31 @@
+RSpec.describe RouteWayCostCalculator do
+  describe "#calculate!" do
+    it "calculates and stores WayCosts in the given route's #cost field" do
+      route = create(:route)
+
+      # Fake the request to the TomTom API, but don't actually send the right
+      # things in the request or response. This is just to fake the request so
+      # we don't actually call their API in tests. The test doesn't test
+      # anything given in the response.
+      stub_request(:post, "https://api.tomtom.com/routing/1/batch/json?key")
+        .with(
+          headers: {
+            'Accept'=>'*/*',
+            'Accept-Encoding'=>'gzip;q=1.0,deflate;q=0.6,identity;q=0.3',
+            'Content-Type'=>'application/json',
+            'User-Agent'=>'Faraday v0.9.2'
+          }
+        )
+        .to_return(
+          status: 200,
+          body: "{\"formatVersion\":\"0.0.1\",\"batchItems\":[{\"statusCode\":200,\"response\":{\"routes\":[{\"summary\":{\"lengthInMeters\":117947,\"travelTimeInSeconds\":7969,\"trafficDelayInSeconds\":0,\"departureTime\":\"2018-03-12T12:32:26+01:00\",\"arrivalTime\":\"2018-03-12T14:45:14+01:00\"}}]}}]}",
+          headers: {}
+        )
+
+      RouteWayCostCalculator.new(route).calculate!
+
+      expect(route.costs).not_to be_nil
+      expect { JSON.parse(JSON.dump(route.costs)) }.not_to raise_error
+    end
+  end
+end