Add winner method to match

app/models/match.rb

@@ -19,13 +19,20 @@ class Match < ApplicationRecord
     stage ? stage.owner : group.owner
   end
 
-  private
+  def winner
+    return nil unless finished?
+    return nil if match_scores.first.points == match_scores.second.points
 
-  def stage_xor_group
+    match_scores.max_by(&:points).team
-    errors.add(:stage_xor_group, 'Stage and Group missing or both present') unless stage.present? ^ group.present?
   end
 
   def group_match?
     group.present?
   end
+
+  private
+
+  def stage_xor_group
+    errors.add(:stage_xor_group, 'Stage and Group missing or both present') unless stage.present? ^ group.present?
+  end
 end

app/services/playoff_stage_service.rb

@@ -70,4 +70,11 @@ class PlayoffStageService
       stage_count.to_int
     end
   end
+
+  def self.populate_match_below(match)
+    current_stage = match.stage
+    next_stage = match.stage.tournament.stages.
+
+                 puts
+  end
 end

spec/models/match_spec.rb

@@ -43,6 +43,20 @@ RSpec.describe Match, type: :model do
     end
   end
 
+  context '#winner' do
+    it 'returns a winner Team for a decided match' do
+      decided_playoff_match = create(:decided_playoff_match)
+      winning_team_match_score = decided_playoff_match.match_scores.first
+      winning_team_match_score.points = 9999
+      winning_team = winning_team_match_score.team
+      expect(decided_playoff_match.winner).to be winning_team
+    end
+
+    it 'returns nil for an undecided match' do
+      expect(create(:undecided_group_match).winner).to be(nil)
+    end
+  end
+
   context '#teams' do
     before do
       @playoff_match = create(:running_playoff_match)