From e1a5e4f73e0e7da204847021bd06e92be20bbcb3 Mon Sep 17 00:00:00 2001
From: Manuel Bustillo <bustikiller@bustikiller.com>
Date: Tue, 22 Jul 2025 15:39:30 +0200
Subject: [PATCH 01/10] Rename perturbation -> optimization to reflect the
 nature of swap and shift operations

---
 app/jobs/table_simulator_job.rb |  4 ++--
 app/services/vns/engine.rb      | 16 ++++++++--------
 lib/tasks/vns.rake              |  4 ++--
 3 files changed, 12 insertions(+), 12 deletions(-)

diff --git a/app/jobs/table_simulator_job.rb b/app/jobs/table_simulator_job.rb
index 51b7256..0471795 100644
--- a/app/jobs/table_simulator_job.rb
+++ b/app/jobs/table_simulator_job.rb
@@ -12,8 +12,8 @@ class TableSimulatorJob < ApplicationJob
     ActsAsTenant.with_tenant(Wedding.find(wedding_id)) do
       engine = VNS::Engine.new
 
-      engine.add_perturbation(Tables::Swap)
-      engine.add_perturbation(Tables::Shift)
+      engine.add_optimization(Tables::Swap)
+      engine.add_optimization(Tables::Shift)
 
       initial_solution = Tables::Distribution.new(min_per_table: MIN_PER_TABLE, max_per_table: MAX_PER_TABLE)
       initial_solution.random_distribution(Guest.potential.shuffle)
diff --git a/app/services/vns/engine.rb b/app/services/vns/engine.rb
index d66c80b..075ad1a 100644
--- a/app/services/vns/engine.rb
+++ b/app/services/vns/engine.rb
@@ -15,23 +15,23 @@ module VNS
       @target_function = function
     end
 
-    def add_perturbation(klass)
-      @perturbations ||= Set.new
-      @perturbations << klass
+    def add_optimization(klass)
+      @optimizations ||= Set.new
+      @optimizations << klass
     end
 
     attr_writer :initial_solution
 
     def run
       raise 'No target function defined' unless @target_function
-      raise 'No perturbations defined' unless @perturbations
+      raise 'No optimizations defined' unless @optimizations
       raise 'No initial solution defined' unless @initial_solution
 
       @best_solution = @initial_solution
       @best_score = @target_function.call(@best_solution)
 
-      self.class.sequence(@perturbations).each do |perturbation|
-        optimize(perturbation)
+      self.class.sequence(@optimizations).each do |optimization|
+        optimize(optimization)
       end
 
       @best_solution
@@ -39,11 +39,11 @@ module VNS
 
     private
 
-    def optimize(perturbation_klass)
+    def optimize(optimization_klass)
       loop do
         optimized = false
 
-        perturbation_klass.new(@best_solution).each do |alternative_solution|
+        optimization_klass.new(@best_solution).each do |alternative_solution|
           score = @target_function.call(alternative_solution)
           next if score >= @best_score
 
diff --git a/lib/tasks/vns.rake b/lib/tasks/vns.rake
index b8c7b3a..9554a76 100644
--- a/lib/tasks/vns.rake
+++ b/lib/tasks/vns.rake
@@ -8,8 +8,8 @@ namespace :vns do
 
       engine = VNS::Engine.new
 
-      engine.add_perturbation(Tables::Swap)
-      engine.add_perturbation(Tables::Shift)
+      engine.add_optimization(Tables::Swap)
+      engine.add_optimization(Tables::Shift)
 
       hierarchy = AffinityGroupsHierarchy.new
       initial_solution = Tables::Distribution.new(min_per_table: 8, max_per_table: 10, hierarchy:)

From 543b53d93858a548086113507b24a98010ac5a4c Mon Sep 17 00:00:00 2001
From: Manuel Bustillo <bustikiller@bustikiller.com>
Date: Tue, 22 Jul 2025 15:53:06 +0200
Subject: [PATCH 02/10] Initialize empty set of perturbations and add debug
 messages

---
 app/services/vns/engine.rb | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/app/services/vns/engine.rb b/app/services/vns/engine.rb
index 075ad1a..ff8758b 100644
--- a/app/services/vns/engine.rb
+++ b/app/services/vns/engine.rb
@@ -20,6 +20,11 @@ module VNS
       @optimizations << klass
     end
 
+    def add_perturbation(klass)
+      @perturbations ||= Set.new
+      @perturbations << klass
+    end
+
     attr_writer :initial_solution
 
     def run
@@ -27,13 +32,18 @@ module VNS
       raise 'No optimizations defined' unless @optimizations
       raise 'No initial solution defined' unless @initial_solution
 
+      @perturbations ||= Set.new
+
       @best_solution = @initial_solution
       @best_score = @target_function.call(@best_solution)
 
       self.class.sequence(@optimizations).each do |optimization|
         optimize(optimization)
+        Rails.logger.debug { "Finished optimization phase: #{optimization.name}" }
       end
 
+      Rails.logger.debug { "Finished all optimization phases" }
+
       @best_solution
     end
 

From 185f35994217f073f19cb8cad4cb511b4cb04580 Mon Sep 17 00:00:00 2001
From: Manuel Bustillo <bustikiller@bustikiller.com>
Date: Tue, 22 Jul 2025 15:56:25 +0200
Subject: [PATCH 03/10] Include additional debugging messages

---
 app/services/vns/engine.rb | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/app/services/vns/engine.rb b/app/services/vns/engine.rb
index ff8758b..f76ec14 100644
--- a/app/services/vns/engine.rb
+++ b/app/services/vns/engine.rb
@@ -39,7 +39,7 @@ module VNS
 
       self.class.sequence(@optimizations).each do |optimization|
         optimize(optimization)
-        Rails.logger.debug { "Finished optimization phase: #{optimization.name}" }
+        Rails.logger.debug { "Finished optimization phase: #{optimization}" }
       end
 
       Rails.logger.debug { "Finished all optimization phases" }
@@ -60,6 +60,7 @@ module VNS
           @best_solution = alternative_solution.deep_dup
           @best_score = score
           optimized = true
+          Rails.logger.debug { "[#{optimization_klass}] Found better solution with score: #{score}" }
 
           break
         end

From e8a88b50e2750abfa4198d317e990a5583379183 Mon Sep 17 00:00:00 2001
From: Manuel Bustillo <bustikiller@bustikiller.com>
Date: Tue, 22 Jul 2025 16:26:28 +0200
Subject: [PATCH 04/10] Initialize Tables::WheelSwap class

---
 app/services/tables/wheel_swap.rb       | 16 ++++++++++++++++
 spec/services/tables/wheel_swap_spec.rb | 21 +++++++++++++++++++++
 2 files changed, 37 insertions(+)
 create mode 100644 app/services/tables/wheel_swap.rb
 create mode 100644 spec/services/tables/wheel_swap_spec.rb

diff --git a/app/services/tables/wheel_swap.rb b/app/services/tables/wheel_swap.rb
new file mode 100644
index 0000000..d932537
--- /dev/null
+++ b/app/services/tables/wheel_swap.rb
@@ -0,0 +1,16 @@
+# Copyright (C) 2024-2025 LibreWeddingPlanner contributors
+
+# frozen_string_literal: true
+
+module Tables
+  class WheelSwap
+    private attr_reader :initial_solution
+    def initialize(initial_solution)
+      @initial_solution = initial_solution
+    end
+
+    def call
+      @initial_solution.deep_dup
+    end
+  end
+end
\ No newline at end of file
diff --git a/spec/services/tables/wheel_swap_spec.rb b/spec/services/tables/wheel_swap_spec.rb
new file mode 100644
index 0000000..19c6b0b
--- /dev/null
+++ b/spec/services/tables/wheel_swap_spec.rb
@@ -0,0 +1,21 @@
+require 'rails_helper'
+
+module Tables
+  RSpec.describe WheelSwap do
+    context "when the solution has three tables" do
+      let(:initial_solution) do
+        Distribution.new(min_per_table: 3, max_per_table: 3).tap do |distribution|
+          distribution.tables << Set[:a, :b, :c].to_table
+          distribution.tables << Set[:d, :e, :f].to_table
+          distribution.tables << Set[:g, :h, :i].to_table
+        end
+      end
+    
+      it "swaps a random guest from each table with a guest from another table", :aggregate_failures do
+        result = described_class.new(initial_solution).call
+        
+        expect(result.tables.size).to eq(3)
+      end
+    end
+  end
+end
\ No newline at end of file

From a1f06dae5bb0b1d3ff4f9c3193f6ab8ba21c02ba Mon Sep 17 00:00:00 2001
From: bustikiller <bustikiller@bustikiller.com>
Date: Wed, 23 Jul 2025 10:22:41 +0200
Subject: [PATCH 05/10] Define a WheelSwap class that randomly swaps one guest
 from each table

---
 app/services/tables/wheel_swap.rb       | 7 ++++++-
 config/initializers/ruby_extensions.rb  | 6 ++++++
 spec/services/tables/wheel_swap_spec.rb | 7 +++++++
 3 files changed, 19 insertions(+), 1 deletion(-)

diff --git a/app/services/tables/wheel_swap.rb b/app/services/tables/wheel_swap.rb
index d932537..b5171a1 100644
--- a/app/services/tables/wheel_swap.rb
+++ b/app/services/tables/wheel_swap.rb
@@ -10,7 +10,12 @@ module Tables
     end
 
     def call
-      @initial_solution.deep_dup
+      new_solution = @initial_solution.deep_dup
+      
+      selected_guests = new_solution.tables.map(&:pop).cycle.tap(&:next)
+      new_solution.tables.each { |table| table << selected_guests.next }
+
+      new_solution
     end
   end
 end
\ No newline at end of file
diff --git a/config/initializers/ruby_extensions.rb b/config/initializers/ruby_extensions.rb
index 47091de..594fa59 100644
--- a/config/initializers/ruby_extensions.rb
+++ b/config/initializers/ruby_extensions.rb
@@ -10,4 +10,10 @@ class Set
   def to_table
     Tables::Table.new(self)
   end
+
+  def pop
+    element = self.to_a.sample
+    self.delete(element)
+    element
+  end
 end
\ No newline at end of file
diff --git a/spec/services/tables/wheel_swap_spec.rb b/spec/services/tables/wheel_swap_spec.rb
index 19c6b0b..20913fd 100644
--- a/spec/services/tables/wheel_swap_spec.rb
+++ b/spec/services/tables/wheel_swap_spec.rb
@@ -15,6 +15,13 @@ module Tables
         result = described_class.new(initial_solution).call
         
         expect(result.tables.size).to eq(3)
+        expect(result.tables.map(&:size)).to all(eq(3))
+
+        expect(result.tables).not_to include(initial_solution.tables[0])
+        expect(result.tables).not_to include(initial_solution.tables[1])
+        expect(result.tables).not_to include(initial_solution.tables[2])
+
+        expect(result.tables.map(&:to_a).flatten).to contain_exactly(*(:a..:i).to_a)
       end
     end
   end

From b1df5d2f53644ea2179cf2f4098cf8444546abf9 Mon Sep 17 00:00:00 2001
From: bustikiller <bustikiller@bustikiller.com>
Date: Wed, 23 Jul 2025 11:01:38 +0200
Subject: [PATCH 06/10] Shuffle guests in WheelSwap before assigning them to
 new tables

---
 app/services/tables/wheel_swap.rb | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/app/services/tables/wheel_swap.rb b/app/services/tables/wheel_swap.rb
index b5171a1..fea238b 100644
--- a/app/services/tables/wheel_swap.rb
+++ b/app/services/tables/wheel_swap.rb
@@ -11,9 +11,10 @@ module Tables
 
     def call
       new_solution = @initial_solution.deep_dup
-      
-      selected_guests = new_solution.tables.map(&:pop).cycle.tap(&:next)
+
+      selected_guests = new_solution.tables.map(&:pop).shuffle.cycle
       new_solution.tables.each { |table| table << selected_guests.next }
+      new_solution.tables.each(&:reset)
 
       new_solution
     end

From 4befb8505b6fe33126e015332be5b21d3d500791 Mon Sep 17 00:00:00 2001
From: bustikiller <bustikiller@bustikiller.com>
Date: Wed, 23 Jul 2025 11:02:32 +0200
Subject: [PATCH 07/10] Run perturbation on top of the best solution so far

---
 app/services/vns/engine.rb | 37 ++++++++++++++++++++++++++++---------
 1 file changed, 28 insertions(+), 9 deletions(-)

diff --git a/app/services/vns/engine.rb b/app/services/vns/engine.rb
index f76ec14..40adbfc 100644
--- a/app/services/vns/engine.rb
+++ b/app/services/vns/engine.rb
@@ -34,30 +34,49 @@ module VNS
 
       @perturbations ||= Set.new
 
-      @best_solution = @initial_solution
-      @best_score = @target_function.call(@best_solution)
+      @current_solution = @initial_solution
+      @best_score = @target_function.call(@current_solution)
 
+      run_all_optimizations
+
+      best_solution = @current_solution
+
+      50.times do
+        @current_solution = Tables::WheelSwap.new(best_solution).call
+        @best_score = @target_function.call(@current_solution)
+        Rails.logger.debug { "After perturbation: #{@best_score}" }
+
+        run_all_optimizations
+
+        if best_solution.discomfort > @current_solution.discomfort
+          best_solution = @current_solution 
+          Rails.logger.debug { "Found better solution after perturbation optimization: #{@current_solution.discomfort}" }
+        end
+      end
+
+
+      best_solution
+    end
+
+    private
+
+    def run_all_optimizations
       self.class.sequence(@optimizations).each do |optimization|
         optimize(optimization)
         Rails.logger.debug { "Finished optimization phase: #{optimization}" }
       end
-
       Rails.logger.debug { "Finished all optimization phases" }
-
-      @best_solution
     end
 
-    private
-
     def optimize(optimization_klass)
       loop do
         optimized = false
 
-        optimization_klass.new(@best_solution).each do |alternative_solution|
+        optimization_klass.new(@current_solution).each do |alternative_solution|
           score = @target_function.call(alternative_solution)
           next if score >= @best_score
 
-          @best_solution = alternative_solution.deep_dup
+          @current_solution = alternative_solution.deep_dup
           @best_score = score
           optimized = true
           Rails.logger.debug { "[#{optimization_klass}] Found better solution with score: #{score}" }

From db85580c1faec0a4beb659e9f41c8857c718541f Mon Sep 17 00:00:00 2001
From: bustikiller <bustikiller@bustikiller.com>
Date: Thu, 24 Jul 2025 13:41:01 +0200
Subject: [PATCH 08/10] Introduce a wheel swap perturbation as part of the VNS
 engine process

---
 app/services/tables/wheel_swap.rb       | 19 +++++++++++++++----
 app/services/vns/engine.rb              | 14 ++++++++------
 spec/services/tables/wheel_swap_spec.rb | 20 +++++++++++---------
 3 files changed, 34 insertions(+), 19 deletions(-)

diff --git a/app/services/tables/wheel_swap.rb b/app/services/tables/wheel_swap.rb
index fea238b..b7d21b8 100644
--- a/app/services/tables/wheel_swap.rb
+++ b/app/services/tables/wheel_swap.rb
@@ -9,14 +9,25 @@ module Tables
       @initial_solution = initial_solution
     end
 
-    def call
+    def call(size = 1)
+      Rails.logger.debug { "WheelSwap with size: #{size}" }
       new_solution = @initial_solution.deep_dup
 
-      selected_guests = new_solution.tables.map(&:pop).shuffle.cycle
-      new_solution.tables.each { |table| table << selected_guests.next }
+      selected_guests = []
+
+      size.times do
+        selected_guests += new_solution.tables.map(&:pop)
+      end
+
+      selected_guests.shuffle!
+
+      tables = new_solution.tables.cycle
+
+      tables.next << selected_guests.pop while selected_guests.any?
+
       new_solution.tables.each(&:reset)
 
       new_solution
     end
   end
-end
\ No newline at end of file
+end
diff --git a/app/services/vns/engine.rb b/app/services/vns/engine.rb
index 40adbfc..dc0feff 100644
--- a/app/services/vns/engine.rb
+++ b/app/services/vns/engine.rb
@@ -4,6 +4,7 @@
 
 module VNS
   class Engine
+    PERTURBATION_SIZES = [1, 1, 1, 2, 2, 3].freeze
     class << self
       def sequence(elements)
         elements = elements.to_a
@@ -42,19 +43,20 @@ module VNS
       best_solution = @current_solution
 
       50.times do
-        @current_solution = Tables::WheelSwap.new(best_solution).call
+        @current_solution = Tables::WheelSwap.new(best_solution).call(PERTURBATION_SIZES.sample)
         @best_score = @target_function.call(@current_solution)
         Rails.logger.debug { "After perturbation: #{@best_score}" }
 
         run_all_optimizations
 
-        if best_solution.discomfort > @current_solution.discomfort
-          best_solution = @current_solution 
-          Rails.logger.debug { "Found better solution after perturbation optimization: #{@current_solution.discomfort}" }
+        next unless best_solution.discomfort > @current_solution.discomfort
+
+        best_solution = @current_solution
+        Rails.logger.debug do
+          "Found better solution after perturbation optimization: #{@current_solution.discomfort}"
         end
       end
 
-
       best_solution
     end
 
@@ -65,7 +67,7 @@ module VNS
         optimize(optimization)
         Rails.logger.debug { "Finished optimization phase: #{optimization}" }
       end
-      Rails.logger.debug { "Finished all optimization phases" }
+      Rails.logger.debug { 'Finished all optimization phases' }
     end
 
     def optimize(optimization_klass)
diff --git a/spec/services/tables/wheel_swap_spec.rb b/spec/services/tables/wheel_swap_spec.rb
index 20913fd..e30c5fc 100644
--- a/spec/services/tables/wheel_swap_spec.rb
+++ b/spec/services/tables/wheel_swap_spec.rb
@@ -1,8 +1,10 @@
+# frozen_string_literal: true
+
 require 'rails_helper'
 
 module Tables
   RSpec.describe WheelSwap do
-    context "when the solution has three tables" do
+    context 'when the solution has three tables' do
       let(:initial_solution) do
         Distribution.new(min_per_table: 3, max_per_table: 3).tap do |distribution|
           distribution.tables << Set[:a, :b, :c].to_table
@@ -10,19 +12,19 @@ module Tables
           distribution.tables << Set[:g, :h, :i].to_table
         end
       end
-    
-      it "swaps a random guest from each table with a guest from another table", :aggregate_failures do
+
+      it 'swaps a random guest from each table with a guest from another table', :aggregate_failures do
         result = described_class.new(initial_solution).call
-        
+
         expect(result.tables.size).to eq(3)
         expect(result.tables.map(&:size)).to all(eq(3))
 
-        expect(result.tables).not_to include(initial_solution.tables[0])
-        expect(result.tables).not_to include(initial_solution.tables[1])
-        expect(result.tables).not_to include(initial_solution.tables[2])
+        # expect(result.tables).not_to include(initial_solution.tables[0])
+        # expect(result.tables).not_to include(initial_solution.tables[1])
+        # expect(result.tables).not_to include(initial_solution.tables[2])
 
-        expect(result.tables.map(&:to_a).flatten).to contain_exactly(*(:a..:i).to_a)
+        expect(result.tables.map(&:to_a).flatten).to match_array((:a..:i).to_a)
       end
     end
   end
-end
\ No newline at end of file
+end

From d18bddb31a0e52fc39e274e2e285a6e3eddf29c2 Mon Sep 17 00:00:00 2001
From: bustikiller <bustikiller@bustikiller.com>
Date: Thu, 24 Jul 2025 13:42:47 +0200
Subject: [PATCH 09/10] Remove commented-out code

---
 spec/services/tables/wheel_swap_spec.rb | 4 ----
 1 file changed, 4 deletions(-)

diff --git a/spec/services/tables/wheel_swap_spec.rb b/spec/services/tables/wheel_swap_spec.rb
index e30c5fc..de5fc5b 100644
--- a/spec/services/tables/wheel_swap_spec.rb
+++ b/spec/services/tables/wheel_swap_spec.rb
@@ -19,10 +19,6 @@ module Tables
         expect(result.tables.size).to eq(3)
         expect(result.tables.map(&:size)).to all(eq(3))
 
-        # expect(result.tables).not_to include(initial_solution.tables[0])
-        # expect(result.tables).not_to include(initial_solution.tables[1])
-        # expect(result.tables).not_to include(initial_solution.tables[2])
-
         expect(result.tables.map(&:to_a).flatten).to match_array((:a..:i).to_a)
       end
     end

From 3260b0b422015018b81b0e4ecd9a404ae5431bdb Mon Sep 17 00:00:00 2001
From: Manuel Bustillo <bustikiller@bustikiller.com>
Date: Thu, 24 Jul 2025 11:46:28 +0000
Subject: [PATCH 10/10] Add copyright notice

---
 spec/services/tables/wheel_swap_spec.rb | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/spec/services/tables/wheel_swap_spec.rb b/spec/services/tables/wheel_swap_spec.rb
index de5fc5b..02dc161 100644
--- a/spec/services/tables/wheel_swap_spec.rb
+++ b/spec/services/tables/wheel_swap_spec.rb
@@ -1,3 +1,5 @@
+# Copyright (C) 2024-2025 LibreWeddingPlanner contributors
+
 # frozen_string_literal: true
 
 require 'rails_helper'