From 1d28cfc527dd5311494c2a9b9cfe77766d1195f4 Mon Sep 17 00:00:00 2001
From: Manuel Bustillo <bustikiller@bustikiller.com>
Date: Fri, 2 Aug 2024 17:37:50 +0200
Subject: [PATCH 1/4] Refactor how the local discomfort is stored

---
 app/services/tables/distribution.rb | 12 ++----------
 app/services/tables/table.rb        | 11 ++++++++---
 2 files changed, 10 insertions(+), 13 deletions(-)

diff --git a/app/services/tables/distribution.rb b/app/services/tables/distribution.rb
index 33cb130..4965346 100644
--- a/app/services/tables/distribution.rb
+++ b/app/services/tables/distribution.rb
@@ -17,9 +17,7 @@ module Tables
     end
 
     def discomfort
-      @tables.map do |table|
-        local_discomfort(table)
-      end.sum
+      @tables.map(&:discomfort).sum
     end
 
     def inspect
@@ -28,7 +26,7 @@ module Tables
 
     def pretty_print
       @tables.map.with_index do |table, i|
-        "Table #{i + 1} (#{table.count} ppl): (#{local_discomfort(table)}) #{table.map(&:full_name).join(', ')}"
+        "Table #{i + 1} (#{table.count} ppl): (#{table.discomfort}) #{table.map(&:full_name).join(', ')}"
       end.join("\n")
     end
 
@@ -55,11 +53,5 @@ module Tables
         arrangement.update!(discomfort:)
       end
     end
-
-    private
-
-    def local_discomfort(table)
-      table.discomfort ||= DiscomfortCalculator.new(table).calculate
-    end
   end
 end
diff --git a/app/services/tables/table.rb b/app/services/tables/table.rb
index 1dde7f6..253c200 100644
--- a/app/services/tables/table.rb
+++ b/app/services/tables/table.rb
@@ -1,15 +1,20 @@
 module Tables
   class Table < Array
-    attr_accessor :discomfort
+    attr_writer :discomfort
+
     def initialize(*args)
       super
       reset
     end
 
     def reset
-      original_discomfort = discomfort
+      original_discomfort = @discomfort
       @discomfort = nil
       original_discomfort
     end
+
+    def discomfort
+      @discomfort ||= DiscomfortCalculator.new(self).calculate
+    end
   end
-end
\ No newline at end of file
+end
-- 
2.47.1


From 60b96ab82dd7987ee7afddeaf559b6b4d37f0364 Mon Sep 17 00:00:00 2001
From: Manuel Bustillo <bustikiller@bustikiller.com>
Date: Fri, 2 Aug 2024 18:17:22 +0200
Subject: [PATCH 2/4] Assign an ID to every table and use a hash to store them

---
 app/services/tables/distribution.rb | 28 +++++++++++++++++++---------
 app/services/tables/table.rb        |  2 ++
 spec/services/tables/swap_spec.rb   | 14 +++++++-------
 3 files changed, 28 insertions(+), 16 deletions(-)

diff --git a/app/services/tables/distribution.rb b/app/services/tables/distribution.rb
index 4965346..5fe0911 100644
--- a/app/services/tables/distribution.rb
+++ b/app/services/tables/distribution.rb
@@ -2,37 +2,47 @@ require_relative '../../extensions/tree_node_extension'
 
 module Tables
   class Distribution
-    attr_accessor :tables
-
     def initialize(min_per_table:, max_per_table:)
       @min_per_table = min_per_table
       @max_per_table = max_per_table
-      @tables = []
+      @tables = {}
+    end
+
+    def tables
+      @tables.values.freeze
+    end
+
+    def <<(array)
+      Table.new(array).tap do |table|
+        @tables[table.id] = table
+      end
     end
 
     def random_distribution(people)
-      @tables = []
+      @tables = {}
 
-      @tables << Table.new(people.slice!(0..rand(@min_per_table..@max_per_table))) while people.any?
+      self << people.slice!(0..rand(@min_per_table..@max_per_table)) while people.any?
     end
 
     def discomfort
-      @tables.map(&:discomfort).sum
+      tables.map(&:discomfort).sum
     end
 
     def inspect
-      "#{@tables.count} tables, discomfort: #{discomfort}"
+      "#{tables.count} tables, discomfort: #{discomfort}"
     end
 
     def pretty_print
-      @tables.map.with_index do |table, i|
+      tables.map.with_index do |table, i|
         "Table #{i + 1} (#{table.count} ppl): (#{table.discomfort}) #{table.map(&:full_name).join(', ')}"
       end.join("\n")
     end
 
     def deep_dup
       self.class.new(min_per_table: @min_per_table, max_per_table: @max_per_table).tap do |new_distribution|
-        new_distribution.tables = @tables.map(&:dup)
+        tables.each do |table|
+          new_distribution << table.dup
+        end
       end
     end
 
diff --git a/app/services/tables/table.rb b/app/services/tables/table.rb
index 253c200..0c9dc2b 100644
--- a/app/services/tables/table.rb
+++ b/app/services/tables/table.rb
@@ -1,10 +1,12 @@
 module Tables
   class Table < Array
     attr_writer :discomfort
+    attr_reader :id
 
     def initialize(*args)
       super
       reset
+      @id = SecureRandom.uuid
     end
 
     def reset
diff --git a/spec/services/tables/swap_spec.rb b/spec/services/tables/swap_spec.rb
index fff181f..b31779f 100644
--- a/spec/services/tables/swap_spec.rb
+++ b/spec/services/tables/swap_spec.rb
@@ -14,8 +14,8 @@ module Tables
       context 'when there are two tables with two people each' do
         let(:initial_solution) do
           Distribution.new(min_per_table: 2, max_per_table: 2).tap do |distribution|
-            distribution.tables << %i[a b].to_table
-            distribution.tables << %i[c d].to_table
+            distribution << %i[a b]
+            distribution << %i[c d]
           end
         end
 
@@ -32,8 +32,8 @@ module Tables
       context 'when there are two tables with three people each' do
         let(:initial_solution) do
           Distribution.new(min_per_table: 3, max_per_table: 3).tap do |distribution|
-            distribution.tables << %i[a b c].to_table
-            distribution.tables << %i[d e f].to_table
+            distribution << %i[a b c]
+            distribution << %i[d e f]
           end
         end
 
@@ -55,9 +55,9 @@ module Tables
       context 'when there are three tables with two people each' do
         let(:initial_solution) do
           Distribution.new(min_per_table: 2, max_per_table: 2).tap do |distribution|
-            distribution.tables << %i[a b].to_table
-            distribution.tables << %i[c d].to_table
-            distribution.tables << %i[e f].to_table
+            distribution << %i[a b]
+            distribution << %i[c d]
+            distribution << %i[e f]
           end
         end
 
-- 
2.47.1


From c2feb229d28c6ef63e5e83f1c423c5476bbc12fb Mon Sep 17 00:00:00 2001
From: Manuel Bustillo <bustikiller@bustikiller.com>
Date: Fri, 2 Aug 2024 18:42:24 +0200
Subject: [PATCH 3/4] Use immutable data structures to calculate variations

---
 app/services/tables/distribution.rb | 19 +++++++++++++++++++
 app/services/tables/swap.rb         | 26 ++++++++++++--------------
 app/services/tables/table.rb        |  6 ++++++
 app/services/vns/engine.rb          |  2 +-
 db/seeds.rb                         |  3 +--
 5 files changed, 39 insertions(+), 17 deletions(-)

diff --git a/app/services/tables/distribution.rb b/app/services/tables/distribution.rb
index 5fe0911..9b5f4ba 100644
--- a/app/services/tables/distribution.rb
+++ b/app/services/tables/distribution.rb
@@ -12,6 +12,22 @@ module Tables
       @tables.values.freeze
     end
 
+    def deep_freeze
+      @tables.each_value(&:freeze)
+      @tables.freeze
+      freeze
+    end
+
+    def replace(table)
+      @tables[table.id] = table
+    end
+
+    def dup
+      super.tap do |new_distribution|
+        new_distribution.instance_variable_set(:@tables, @tables.dup)
+      end
+    end
+
     def <<(array)
       Table.new(array).tap do |table|
         @tables[table.id] = table
@@ -22,6 +38,9 @@ module Tables
       @tables = {}
 
       self << people.slice!(0..rand(@min_per_table..@max_per_table)) while people.any?
+
+      @tables.freeze
+      freeze
     end
 
     def discomfort
diff --git a/app/services/tables/swap.rb b/app/services/tables/swap.rb
index 631b49b..d77e2a4 100644
--- a/app/services/tables/swap.rb
+++ b/app/services/tables/swap.rb
@@ -8,25 +8,23 @@ module Tables
     def each
       @initial_solution.tables.combination(2) do |table_a, table_b|
         table_a.product(table_b).each do |(person_a, person_b)|
-          original_discomfort_a = table_a.reset
-          original_discomfort_b = table_b.reset
+          new_solution = @initial_solution.dup
 
-          table_a.delete(person_a)
-          table_b.delete(person_b)
+          new_table_a = table_a.dup
+          new_table_b = table_b.dup
 
-          table_a << person_b
-          table_b << person_a
+          new_solution.replace(new_table_a)
+          new_solution.replace(new_table_b)
 
-          yield(@initial_solution)
-        ensure
-          table_a.delete(person_b)
-          table_b.delete(person_a)
+          new_table_a.delete(person_a)
+          new_table_b.delete(person_b)
 
-          table_a << person_a
-          table_b << person_b
+          new_table_a << person_b
+          new_table_b << person_a
 
-          table_a.discomfort = original_discomfort_a
-          table_b.discomfort = original_discomfort_b
+          new_solution.freeze
+
+          yield(new_solution)
         end
       end
     end
diff --git a/app/services/tables/table.rb b/app/services/tables/table.rb
index 0c9dc2b..54fd8cc 100644
--- a/app/services/tables/table.rb
+++ b/app/services/tables/table.rb
@@ -18,5 +18,11 @@ module Tables
     def discomfort
       @discomfort ||= DiscomfortCalculator.new(self).calculate
     end
+
+    def dup
+      super.tap do |new_table|
+        new_table.discomfort = nil
+      end
+    end
   end
 end
diff --git a/app/services/vns/engine.rb b/app/services/vns/engine.rb
index 5c260aa..d5474b9 100644
--- a/app/services/vns/engine.rb
+++ b/app/services/vns/engine.rb
@@ -26,7 +26,7 @@ module VNS
         optimize(perturbation.new(@best_solution))
       end
 
-      @best_solution 
+      @best_solution
     end
 
     private
diff --git a/db/seeds.rb b/db/seeds.rb
index 162a80f..eb08d7a 100644
--- a/db/seeds.rb
+++ b/db/seeds.rb
@@ -1,4 +1,4 @@
-NUMBER_OF_GUESTS = 50
+NUMBER_OF_GUESTS = ENV['SEED_GUEST_COUNT'].presence.to_i || 50
 
 TablesArrangement.delete_all
 Expense.delete_all
@@ -21,7 +21,6 @@ Expense.create!(name: 'Transportation', amount: 3000, pricing_type: 'fixed')
 Expense.create!(name: 'Invitations', amount: 200, pricing_type: 'fixed')
 Expense.create!(name: 'Cake', amount: 500, pricing_type: 'fixed')
 
-
 samples = {
   close_family_a: 10,
   close_family_b: 10,
-- 
2.47.1


From 5f50c1fe111bca83891934295abe79db5550809d Mon Sep 17 00:00:00 2001
From: Manuel Bustillo <bustikiller@bustikiller.com>
Date: Fri, 2 Aug 2024 18:45:28 +0200
Subject: [PATCH 4/4] Fix seedfile

---
 db/seeds.rb | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/db/seeds.rb b/db/seeds.rb
index eb08d7a..194fa88 100644
--- a/db/seeds.rb
+++ b/db/seeds.rb
@@ -1,4 +1,4 @@
-NUMBER_OF_GUESTS = ENV['SEED_GUEST_COUNT'].presence.to_i || 50
+NUMBER_OF_GUESTS = (ENV['SEED_GUEST_COUNT'] || 50).to_i
 
 TablesArrangement.delete_all
 Expense.delete_all
-- 
2.47.1