Improve bus stops sort order in bus route page

app/controllers/bus_routes_controller.rb

@@ -1,5 +1,6 @@
 class BusRoutesController < ApplicationController
   def show
-    @bus_route = BusRoute.preload(:bus_route_tracks, bus_stops: [:bus_routes]).find(params[:id])
+    # Don't use preload for keeping bus stop order (Use fragment cache)
+    @bus_route = BusRoute.find(params[:id])
   end
 end

app/models/bus_route.rb

@@ -1,7 +1,7 @@
 class BusRoute < ActiveRecord::Base
   has_many :bus_route_tracks
-  has_many :bus_route_bus_stops
-  has_many :bus_stops, -> { order('name, latitude DESC') }, through: :bus_route_bus_stops
+  has_many :bus_route_bus_stops, -> { order(:bus_stop_number) }
+  has_many :bus_stops, through: :bus_route_bus_stops
 
   enum bus_type: { private_bus: 1, public_bus: 2, community_bus: 3, demand_bus: 4, other: 5 }
 

db/seeds.rb

@@ -76,7 +76,34 @@ def load_bus_stops
   end
 end
 
+def order_bus_stops
+  BusRouteBusStop.update_all(bus_stop_number: nil)
+
+  order_progress = ProgressBar.create(title: "Ordering", total: BusRoute.count, format: '%t: %J%% |%B|')
+  BusRoute.all.each do |bus_route|
+    index = 0
+    bus_route.bus_route_tracks.sort_by{|t| t.coordinates[0][1] }.each do |track|
+      track.coordinates.each do |coordinate|
+        latitude = coordinate[0]
+        longitude = coordinate[1]
+        bus_route.bus_route_bus_stops.each do |bus_route_bus_stop|
+          next if bus_route_bus_stop.bus_stop_number
+          bus_stop = bus_route_bus_stop.bus_stop
+          distance = (bus_stop.latitude - latitude) ** 2 + (bus_stop.longitude - longitude) ** 2
+          if distance < 0.000001 then
+            bus_route_bus_stop.bus_stop_number = index += 1
+            bus_route_bus_stop.save
+            break
+          end
+        end
+      end
+    end
+    order_progress.increment
+  end
+end
+
 ActiveRecord::Base.transaction do
   load_bus_routes
   load_bus_stops
+  order_bus_stops
 end