app/services/tables/distribution.rb

@@ -2,39 +2,66 @@ 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 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
+      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?
+
+      @tables.freeze
+      freeze
     end
 
     def discomfort
-      @tables.map do |table|
+      tables.map(&:discomfort).sum
-        local_discomfort(table)
-      end.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): (#{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
 
     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
 
@@ -55,11 +82,5 @@ module Tables
         arrangement.update!(discomfort:)
       end
     end
-
-    private
-
-    def local_discomfort(table)
-      table.discomfort ||= DiscomfortCalculator.new(table).calculate
-    end
   end
 end

app/services/tables/swap.rb

@@ -7,26 +7,26 @@ 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)|
+        table_a.swap_candidates.product(table_b.swap_candidates).each do |(person_a, person_b)|
-          original_discomfort_a = table_a.reset
+          next if person_a.affinity_group_list.first == person_b.affinity_group_list.first
-          original_discomfort_b = table_b.reset
 
-          table_a.delete(person_a)
+          new_solution = @initial_solution.dup
-          table_b.delete(person_b)
 
-          table_a << person_b
+          new_table_a = table_a.dup
-          table_b << person_a
+          new_table_b = table_b.dup
 
-          yield(@initial_solution)
+          new_solution.replace(new_table_a)
-        ensure
+          new_solution.replace(new_table_b)
-          table_a.delete(person_b)
-          table_b.delete(person_a)
 
-          table_a << person_a
+          new_table_a.delete(person_a)
-          table_b << person_b
+          new_table_b.delete(person_b)
 
-          table_a.discomfort = original_discomfort_a
+          new_table_a << person_b
-          table_b.discomfort = original_discomfort_b
+          new_table_b << person_a
+
+          new_solution.freeze
+
+          yield(new_solution)
         end
       end
     end

app/services/tables/table.rb

@@ -1,15 +1,25 @@
 module Tables
   class Table < Array
-    attr_accessor :discomfort
+    attr_writer :discomfort
+    attr_reader :id
+
     def initialize(*args)
       super
-      reset
+      @id = SecureRandom.uuid
     end
 
-    def reset
+    def discomfort
-      original_discomfort = discomfort
+      @discomfort ||= DiscomfortCalculator.new(self).calculate
-      @discomfort = nil
+    end
-      original_discomfort
+
+    def swap_candidates
+      @swap_candidates ||= uniq { |person| person.affinity_group_list.first }
+    end
+
+    def dup
+      super.tap do |new_table|
+        new_table.discomfort = nil
+      end
     end
   end
 end

db/seeds.rb

@@ -1,4 +1,4 @@
-NUMBER_OF_GUESTS = 50
+NUMBER_OF_GUESTS = (ENV['SEED_GUEST_COUNT'] || 50).to_i
 
 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,

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 << %i[a b]
-            distribution.tables << %i[c d].to_table
+            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 << %i[a b c]
-            distribution.tables << %i[d e f].to_table
+            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 << %i[a b]
-            distribution.tables << %i[c d].to_table
+            distribution << %i[c d]
-            distribution.tables << %i[e f].to_table
+            distribution << %i[e f]
           end
         end