# frozen_string_literal: true

require 'spec_helper'

describe Gitlab::CurrentSettings do
  before do
    stub_env('IN_MEMORY_APPLICATION_SETTINGS', 'false')
  end

  shared_context 'with settings in cache' do
    before do
      create(:application_setting)
      described_class.current_application_settings # warm the cache
    end
  end

  describe '#current_application_settings', :use_clean_rails_memory_store_caching do
    it 'allows keys to be called directly' do
      db_settings = create(:application_setting,
        home_page_url: 'http://mydomain.com',
        signup_enabled: false)

      expect(described_class.home_page_url).to eq(db_settings.home_page_url)
      expect(described_class.signup_enabled?).to be_falsey
      expect(described_class.signup_enabled).to be_falsey
      expect(described_class.metrics_sample_interval).to be(15)
    end

    context 'when ENV["IN_MEMORY_APPLICATION_SETTINGS"] is true' do
      before do
        stub_env('IN_MEMORY_APPLICATION_SETTINGS', 'true')
      end

      it 'returns an in-memory ApplicationSetting object' do
        expect(ApplicationSetting).not_to receive(:current)

        expect(described_class.current_application_settings).to be_a(ApplicationSetting)
        expect(described_class.current_application_settings).not_to be_persisted
      end
    end

    context 'with DB unavailable' do
      context 'and settings in cache' do
        include_context 'with settings in cache'

        it 'fetches the settings from cache without issuing any query' do
          expect(ActiveRecord::QueryRecorder.new { described_class.current_application_settings }.count).to eq(0)
        end
      end

      context 'and no settings in cache' do
        before do
          # For some reason, `allow(described_class).to receive(:connect_to_db?).and_return(false)` causes issues
          # during the initialization phase of the test suite, so instead let's mock the internals of it
          allow(ActiveRecord::Base.connection).to receive(:active?).and_return(false)
          expect(ApplicationSetting).not_to receive(:current)
        end

        it 'returns a FakeApplicationSettings object' do
          expect(described_class.current_application_settings).to be_a(Gitlab::FakeApplicationSettings)
        end

        it 'does not issue any query' do
          expect(ActiveRecord::QueryRecorder.new { described_class.current_application_settings }.count).to eq(0)
        end
      end
    end

    context 'with DB available' do
      # This method returns the ::ApplicationSetting.defaults hash
      # but with respect of custom attribute accessors of ApplicationSetting model
      def settings_from_defaults
        ar_wrapped_defaults = ::ApplicationSetting.build_from_defaults.attributes
        ar_wrapped_defaults.slice(*::ApplicationSetting.defaults.keys)
      end

      context 'and settings in cache' do
        include_context 'with settings in cache'

        it 'fetches the settings from cache' do
          # For some reason, `allow(described_class).to receive(:connect_to_db?).and_return(true)` causes issues
          # during the initialization phase of the test suite, so instead let's mock the internals of it
          expect(ActiveRecord::Base.connection).not_to receive(:active?)
          expect(ActiveRecord::Base.connection).not_to receive(:cached_table_exists?)
          expect_any_instance_of(ActiveRecord::MigrationContext).not_to receive(:needs_migration?)
          expect(ActiveRecord::QueryRecorder.new { described_class.current_application_settings }.count).to eq(0)
        end
      end

      context 'and no settings in cache' do
        before do
          allow(ActiveRecord::Base.connection).to receive(:active?).and_return(true)
          allow(ActiveRecord::Base.connection).to receive(:cached_table_exists?).with('application_settings').and_return(true)
        end

        context 'with RequestStore enabled', :request_store do
          it 'fetches the settings from DB only once' do
            described_class.current_application_settings # warm the cache

            expect(ActiveRecord::QueryRecorder.new { described_class.current_application_settings }.count).to eq(0)
          end
        end

        it 'creates default ApplicationSettings if none are present' do
          settings = described_class.current_application_settings

          expect(settings).to be_a(ApplicationSetting)
          expect(settings).to be_persisted
          expect(settings).to have_attributes(settings_from_defaults)
        end

        context 'with pending migrations' do
          before do
            expect_any_instance_of(ActiveRecord::MigrationContext).to receive(:needs_migration?).and_return(true)
          end

          shared_examples 'a non-persisted ApplicationSetting object' do
            let(:current_settings) { described_class.current_application_settings }

            it 'returns a FakeApplicationSettings object' do
              expect(current_settings).to be_a(Gitlab::FakeApplicationSettings)
            end

            it 'uses the default value from ApplicationSetting.defaults' do
              expect(current_settings.signup_enabled).to eq(ApplicationSetting.defaults[:signup_enabled])
            end

            it 'uses the default value from custom ApplicationSetting accessors' do
              expect(current_settings.commit_email_hostname).to eq(ApplicationSetting.default_commit_email_hostname)
            end

            it 'responds to predicate methods' do
              expect(current_settings.signup_enabled?).to eq(current_settings.signup_enabled)
            end
          end

          context 'with no ApplicationSetting DB record' do
            it_behaves_like 'a non-persisted ApplicationSetting object'
          end

          context 'with an existing ApplicationSetting DB record' do
            let!(:db_settings) { ApplicationSetting.build_from_defaults(home_page_url: 'http://mydomain.com').save! && ApplicationSetting.last }
            let(:current_settings) { described_class.current_application_settings }

            it_behaves_like 'a non-persisted ApplicationSetting object'

            it 'uses the value from the DB attribute if present and not overridden by an accessor' do
              expect(current_settings.home_page_url).to eq(db_settings.home_page_url)
            end

            context 'when a new column is used before being migrated' do
              before do
                allow(ApplicationSetting).to receive(:defaults).and_return({ foo: 'bar' })
              end

              it 'uses the default value if present' do
                expect(current_settings.foo).to eq('bar')
              end
            end
          end
        end

        context 'when ApplicationSettings.current is present' do
          it 'returns the existing application settings' do
            expect(ApplicationSetting).to receive(:current).and_return(:current_settings)

            expect(described_class.current_application_settings).to eq(:current_settings)
          end
        end

        context 'when the application_settings table does not exist' do
          it 'returns a FakeApplicationSettings object' do
            expect(Gitlab::Database)
              .to receive(:cached_table_exists?)
              .with('application_settings')
              .and_return(false)

            expect(described_class.current_application_settings).to be_a(Gitlab::FakeApplicationSettings)
          end
        end
      end
    end
  end
end