Assign :intermediate_stage to first stage if single_team matches present

app/models/stage.rb

@@ -1,7 +1,7 @@
 # frozen_string_literal: true
 
 class Stage < ApplicationRecord
-  enum state: %i[playoff_stage in_progress finished]
+  enum state: %i[playoff_stage intermediate_stage in_progress finished]
 
   belongs_to :tournament
   has_many :matches, dependent: :destroy

app/services/playoff_stage_service.rb

@@ -12,6 +12,7 @@ class PlayoffStageService
       # initial_matches are the matches in the first stage; this is the only stage filled with teams from the start on
       initial_matches = MatchService.generate_matches(teams)
       initial_stage = Stage.new level: stage_count - 1, matches: initial_matches
+      initial_stage.state = :intermediate_stage unless initial_stage.matches.find(&:single_team?).nil?
       playoffs << initial_stage
       # empty stages are the stages, the tournament is filled with to have the matches ready for later
       empty_stages = generate_stages_with_empty_matches(stage_count - 1)

spec/services/playoff_stage_service_spec.rb

@@ -79,6 +79,38 @@ RSpec.describe PlayoffStageService do
         end
       end
     end
+
+    describe 'number of teams isn\'t a power of two' do
+      let(:generated_stages) do
+        PlayoffStageService.generate_playoff_stages(create_list(:team, 12))
+      end
+
+      let(:intermediate_stage) do
+        generated_stages.max_by(&:level)
+      end
+
+      it 'generates an intermediate stage at the top level' do
+        expect(intermediate_stage.state).to eq('intermediate_stage')
+      end
+
+      it 'generates normal playoff_stage state stages elsewhere' do
+        (generated_stages - [intermediate_stage]).each do |stage|
+          expect(stage.state).to eq('playoff_stage')
+        end
+      end
+    end
+
+    describe 'number of teams is a power of two' do
+      let(:generated_stages) do
+        PlayoffStageService.generate_playoff_stages(create_list(:team, 16))
+      end
+
+      it 'generates only normal playoff_stage state stages' do
+        generated_stages.each do |stage|
+          expect(stage.state).to eq('playoff_stage')
+        end
+      end
+    end
   end
 
   describe '#populate_match_below' do