Add StatisticsController

app/controllers/statistics_controller.rb

@@ -0,0 +1,26 @@
+# frozen_string_literal: true
+
+class StatisticsController < ApplicationController
+  before_action :set_tournament, only: %i[index]
+
+  # GET /tournaments/1/statistics
+  def index
+    group_stage = @tournament.stages.find_by(level: -1)
+    if group_stage
+      service = StatisticsService.new group_stage
+      render json: {
+        most_dominant_score: service.most_dominant_score,
+        least_dominant_score: service.least_dominant_score,
+        group_scores: service.group_scores
+      }
+    else
+      render json: {}, status: :not_implemented
+    end
+  end
+
+  private
+
+  def set_tournament
+    @tournament = Tournament.find(params[:tournament_id])
+  end
+end

spec/controllers/statistics_controller_spec.rb

@@ -0,0 +1,50 @@
+# frozen_string_literal: true
+
+require 'rails_helper'
+
+RSpec.describe StatisticsController, type: :controller do
+  describe 'GET #index' do
+    context 'tournament without a group stage' do
+      it 'returns a not implemented response' do
+        get :index, params: { tournament_id: create(:tournament).to_param }
+        expect(response).to have_http_status(:not_implemented)
+      end
+    end
+
+    context 'tournament with a group stage' do
+      before do
+        @tournament = create(:group_stage_tournament)
+        @group_stage = @tournament.stages.find_by(level: -1)
+        @most_dominant_score = GroupScore.new team: @tournament.teams.first,
+                                              group_points: 100,
+                                              scored_points: 100, received_points: 0
+        @least_dominant_score = GroupScore.new team: @tournament.teams.first,
+                                               group_points: 0,
+                                               scored_points: 0, received_points: 100
+        @tournament.stages.first.groups.first.group_scores << @most_dominant_score
+        @tournament.stages.first.groups.first.group_scores << @least_dominant_score
+        @tournament.save!
+      end
+
+      it 'returns a success response' do
+        get :index, params: { tournament_id: @tournament.to_param }
+        expect(response).to be_successful
+      end
+
+      it 'returns a list containing all group scores' do
+        get :index, params: { tournament_id: @tournament.to_param }
+        expect(deserialize_response(response)[:group_scores].length).to eq(GroupScore.count)
+      end
+
+      it 'returns a most dominant group score' do
+        get :index, params: { tournament_id: @tournament.to_param }
+        expect(deserialize_response(response)[:most_dominant_score][:id]).to eq(@most_dominant_score.id)
+      end
+
+      it 'returns a least dominant group score' do
+        get :index, params: { tournament_id: @tournament.to_param }
+        expect(deserialize_response(response)[:least_dominant_score][:id]).to eq(@least_dominant_score.id)
+      end
+    end
+  end
+end