# frozen_string_literal: true

require 'spec_helper'

RSpec.describe Projects::Ml::ExperimentsController, feature_category: :mlops do
  let_it_be(:project_with_feature) { create(:project, :repository) }
  let_it_be(:user) { project_with_feature.first_owner }
  let_it_be(:project_without_feature) do
    create(:project, :repository).tap { |p| p.add_developer(user) }
  end

  let_it_be(:experiment) do
    create(:ml_experiments, project: project_with_feature, user: user).tap do |e|
      create(:ml_candidates, experiment: e, user: user)
    end
  end

  let(:params) { basic_params }
  let(:ff_value) { true }
  let(:project) { project_with_feature }
  let(:basic_params) { { namespace_id: project.namespace.to_param, project_id: project } }

  before do
    stub_feature_flags(ml_experiment_tracking: false)
    stub_feature_flags(ml_experiment_tracking: project_with_feature) if ff_value

    sign_in(user)
  end

  shared_examples '404 if feature flag disabled' do
    context 'when :ml_experiment_tracking disabled' do
      let(:ff_value) { false }

      it 'is 404' do
        expect(response).to have_gitlab_http_status(:not_found)
      end
    end
  end

  describe 'GET index' do
    before do
      list_experiments
    end

    it 'renders the template' do
      expect(response).to render_template('projects/ml/experiments/index')
    end

    it 'does not perform N+1 sql queries' do
      control_count = ActiveRecord::QueryRecorder.new(skip_cached: false) { list_experiments }

      create_list(:ml_experiments, 2, project: project, user: user)

      expect { list_experiments }.not_to exceed_all_query_limit(control_count)
    end

    context 'when :ml_experiment_tracking is disabled for the project' do
      let(:project) { project_without_feature }

      it 'responds with a 404' do
        expect(response).to have_gitlab_http_status(:not_found)
      end
    end

    it_behaves_like '404 if feature flag disabled'
  end

  describe 'GET show' do
    let(:params) { basic_params.merge(id: experiment.iid) }

    it 'renders the template' do
      show_experiment

      expect(response).to render_template('projects/ml/experiments/show')
    end

    describe 'pagination' do
      let_it_be(:candidates) { create_list(:ml_candidates, 5, experiment: experiment) }

      before do
        stub_const("Projects::Ml::ExperimentsController::MAX_CANDIDATES_PER_PAGE", 2)
        candidates

        show_experiment
      end

      context 'when out of bounds' do
        let(:params) { basic_params.merge(id: experiment.iid, page: 10000) }

        it 'redirects to last page' do
          last_page = (experiment.candidates.size + 1) / 2

          expect(response).to redirect_to(project_ml_experiment_path(project, experiment.iid, page: last_page))
        end
      end

      context 'when bad page' do
        let(:params) { basic_params.merge(id: experiment.iid, page: 's') }

        it 'uses first page' do
          expect(assigns(:pagination)).to include(
            page: 1,
            is_last_page: false,
            per_page: 2,
            total_items: experiment.candidates&.size
          )
        end
      end
    end

    it 'does not perform N+1 sql queries' do
      control_count = ActiveRecord::QueryRecorder.new(skip_cached: false) { show_experiment }

      create_list(:ml_candidates, 2, :with_metrics_and_params, experiment: experiment)

      expect { show_experiment }.not_to exceed_all_query_limit(control_count)
    end

    it_behaves_like '404 if feature flag disabled' do
      before do
        show_experiment
      end
    end
  end

  private

  def show_experiment
    get project_ml_experiment_path(project, experiment.iid), params: params
  end

  def list_experiments
    get project_ml_experiments_path(project), params: params
  end
end