3 files changed, 157 insertions, 0 deletions
diff --git a/lib/tom_tom/matrix.rb b/lib/tom_tom/matrix.rb
new file mode 100644
index 000000000..b0c8cc335
--- /dev/null
+++ b/lib/tom_tom/matrix.rb
@@ -0,0 +1,114 @@
+module TomTom
+  class Matrix
+    def initialize(connection)
+      @connection = connection
+    end
+
+    def matrix(way_costs)
+      points_with_ids = points_from_way_costs(way_costs)
+      points = points_as_params(points_with_ids)
+
+      Rails.logger.info "Invoke TomTom for #{points.size} points"
+
+      response = @connection.post do |req|
+        req.url '/routing/1/matrix/json'
+        req.headers['Content-Type'] = 'application/json'
+
+        req.params[:routeType] = 'shortest'
+        req.params[:travelMode] = 'bus'
+
+        req.body = build_request_body(points)
+      end
+
+      extract_costs_to_way_costs!(
+        way_costs,
+        points_with_ids,
+        JSON.parse(response.body)
+      )
+    end
+
+    def points_from_way_costs(way_costs)
+      points = []
+
+      way_costs.each do |way_cost|
+        departure_id, arrival_id = way_cost.id.split('-')
+
+        departure = TomTom::Matrix::Point.new(
+          way_cost.departure,
+          departure_id
+        )
+        arrival = TomTom::Matrix::Point.new(
+          way_cost.arrival,
+          arrival_id
+        )
+
+        # Don't add duplicate coordinates. This assumes that
+        # `way_costs` consists of an ordered route of points where
+        # each departure coordinate is the same as the preceding
+        # arrival coordinate.
+        if points.empty? ||
+            points.last.coordinates != departure.coordinates
+          points << departure
+        end
+
+        points << arrival
+      end
+
+      points
+    end
+
+    def points_as_params(points)
+      points.map do |point|
+        {
+          point: {
+            latitude: point.coordinates.lat,
+            longitude: point.coordinates.lng
+          }
+        }
+      end
+    end
+
+    def build_request_body(points)
+      # Serialize `BigDecimal` values as floats to please the TomTom API
+      RequestJSONSerializer.dump({
+        origins: points,
+        destinations: points
+      })
+    end
+
+    def extract_costs_to_way_costs!(way_costs, points, matrix_json)
+      way_costs = []
+
+      # `row` and `column` order is the same as `points`
+      matrix_json['matrix'].each_with_index do |row, row_i|
+        row.each_with_index do |column, column_i|
+          next if column['statusCode'] != 200
+
+          distance = column['response']['routeSummary']['lengthInMeters']
+
+          # Ignore costs between a point and itself (e.g. from A to A)
+          next if distance == 0
+
+          departure = points[row_i]
+          arrival = points[column_i]
+
+          way_costs << WayCost.new(
+            departure: Geokit::LatLng.new(
+              departure.coordinates.lat,
+              departure.coordinates.lng
+            ),
+            arrival: Geokit::LatLng.new(
+              arrival.coordinates.lat,
+              arrival.coordinates.lng
+            ),
+            distance: distance,
+            time: column['response']['routeSummary']['travelTimeInSeconds'],
+            id: "#{departure.id}-#{arrival.id}"
+          )
+        end
+      end
+
+      way_costs
+    end
+  end
+end
diff --git a/lib/tom_tom/matrix/point.rb b/lib/tom_tom/matrix/point.rb
new file mode 100644
index 000000000..435b4d4b0
--- /dev/null
+++ b/lib/tom_tom/matrix/point.rb
@@ -0,0 +1,18 @@
+module TomTom
+  class Matrix
+    class Point
+      attr_reader :coordinates, :id
+
+      def initialize(coordinates, id)
+        @coordinates = coordinates
+        @id = id
+      end
+
+      def ==(other)
+        other.is_a?(self.class) &&
+          @coordinates == other.coordinates &&
+          @id == other.id
+      end
+    end
+  end
+end
diff --git a/lib/tom_tom/matrix/request_json_serializer.rb b/lib/tom_tom/matrix/request_json_serializer.rb
new file mode 100644
index 000000000..f4d12e482
--- /dev/null
+++ b/lib/tom_tom/matrix/request_json_serializer.rb
@@ -0,0 +1,25 @@
+module TomTom
+  class Matrix
+    class RequestJSONSerializer
+      def self.dump(hash)
+        hash[:origins].map! do |point|
+          point_to_f(point)
+        end
+        hash[:destinations].map! do |point|
+          point_to_f(point)
+        end
+
+        JSON.dump(hash)
+      end
+
+      private
+
+      def self.point_to_f(point)
+        point[:point][:latitude] = point[:point][:latitude].to_f
+        point[:point][:longitude] = point[:point][:longitude].to_f
+
+        point
+      end
+    end
+  end
+end