Move VNS implementation to the project

Gemfile

@@ -67,5 +67,4 @@ end
 gem "money"
 gem 'acts-as-taggable-on'
 
-gem "vns", path: "../vns"
 gem "rubytree"

Gemfile.lock

@@ -1,9 +1,3 @@
-PATH
-  remote: ../vns
-  specs:
-    vns (0.4.0.pre.rc.1)
-      activesupport
-
 GEM
   remote: https://rubygems.org/
   specs:
@@ -106,8 +100,6 @@ GEM
       factory_bot (~> 6.4)
       railties (>= 5.0.0)
     faker (3.1.1)
-    faker (3.4.2)
-      i18n (>= 1.8.11, < 2)
     globalid (1.2.1)
       activesupport (>= 6.1)
     i18n (1.14.5)
@@ -293,7 +285,6 @@ DEPENDENCIES
   stimulus-rails
   turbo-rails
   tzinfo-data
-  vns!
   web-console
 
 RUBY VERSION

app/services/vns/engine.rb

@@ -0,0 +1,48 @@
+module VNS
+  class Engine
+    def target_function(&function)
+      @target_function = function
+    end
+
+    def add_perturbation(klass)
+      @perturbations ||= Set.new
+      @perturbations << klass
+    end
+
+    attr_writer :initial_solution
+
+    def run
+      raise 'No target function defined' unless @target_function
+      raise 'No perturbations defined' unless @perturbations
+      raise 'No initial solution defined' unless @initial_solution
+
+      @best_solution = @initial_solution
+      @best_score = @target_function.call(@best_solution)
+
+      puts "Initial score: #{@best_score.to_f}"
+
+      @perturbations.each do |perturbation|
+        puts "Running perturbation: #{perturbation.name}"
+        optimize(perturbation.new(@best_solution))
+      end
+
+      @best_solution 
+    end
+
+    private
+
+    def optimize(perturbation)
+      perturbation.each do |alternative_solution|
+        score = @target_function.call(alternative_solution)
+        next if score >= @best_score
+
+        @best_solution = alternative_solution.deep_dup
+        @best_score = score
+
+        puts "New lowest score: #{@best_score.to_f}"
+
+        return optimize(perturbation.class.new(@best_solution))
+      end
+    end
+  end
+end

config/initializers/inflections.rb

@@ -11,6 +11,6 @@
 # end
 
 # These inflection rules are supported but not enabled by default:
-# ActiveSupport::Inflector.inflections(:en) do |inflect|
+ActiveSupport::Inflector.inflections(:en) do |inflect|
-#   inflect.acronym "RESTful"
+  inflect.acronym 'VNS'
-# end
+end