# frozen_string_literal: true

require 'spec_helper'

RSpec.describe Gitlab::Database::LoadBalancing::SidekiqServerMiddleware do
  let(:middleware) { described_class.new }

  after do
    Gitlab::Database::LoadBalancing::Session.clear_session
  end

  describe '#call' do
    shared_context 'data consistency worker class' do |data_consistency, feature_flag|
      let(:worker_class) do
        Class.new do
          def self.name
            'TestDataConsistencyWorker'
          end

          include ApplicationWorker

          data_consistency data_consistency, feature_flag: feature_flag

          def perform(*args)
          end
        end
      end

      before do
        stub_const('TestDataConsistencyWorker', worker_class)
      end
    end

    shared_examples_for 'stick to the primary' do
      it 'sticks to the primary' do
        middleware.call(worker, job, double(:queue)) do
          expect(Gitlab::Database::LoadBalancing::Session.current.use_primary?).to be_truthy
        end
      end
    end

    shared_examples_for 'replica is up to date' do |location, data_consistency|
      it 'does not stick to the primary', :aggregate_failures do
        expect(middleware).to receive(:replica_caught_up?).with(location).and_return(true)

        middleware.call(worker, job, double(:queue)) do
          expect(Gitlab::Database::LoadBalancing::Session.current.use_primary?).not_to be_truthy
        end

        expect(job[:database_chosen]).to eq('replica')
      end

      it "updates job hash with data_consistency :#{data_consistency}" do
        middleware.call(worker, job, double(:queue)) do
          expect(job).to include(data_consistency: data_consistency.to_s)
        end
      end
    end

    shared_examples_for 'sticks based on data consistency' do |data_consistency|
      include_context 'data consistency worker class', data_consistency, :load_balancing_for_test_data_consistency_worker

      context 'when load_balancing_for_test_data_consistency_worker is disabled' do
        before do
          stub_feature_flags(load_balancing_for_test_data_consistency_worker: false)
        end

        include_examples 'stick to the primary'
      end

      context 'when database replica location is set' do
        let(:job) { { 'job_id' => 'a180b47c-3fd6-41b8-81e9-34da61c3400e', 'database_replica_location' => '0/D525E3A8' } }

        before do
          allow(middleware).to receive(:replica_caught_up?).and_return(true)
        end

        it_behaves_like 'replica is up to date', '0/D525E3A8', data_consistency
      end

      context 'when database primary location is set' do
        let(:job) { { 'job_id' => 'a180b47c-3fd6-41b8-81e9-34da61c3400e', 'database_write_location' => '0/D525E3A8' } }

        before do
          allow(middleware).to receive(:replica_caught_up?).and_return(true)
        end

        it_behaves_like 'replica is up to date', '0/D525E3A8', data_consistency
      end

      context 'when database location is not set' do
        let(:job) { { 'job_id' => 'a180b47c-3fd6-41b8-81e9-34da61c3400e' } }

        it_behaves_like 'stick to the primary', nil
      end
    end

    let(:queue) { 'default' }
    let(:redis_pool) { Sidekiq.redis_pool }
    let(:worker) { worker_class.new }
    let(:job) { { "retry" => 3, "job_id" => "a180b47c-3fd6-41b8-81e9-34da61c3400e", 'database_replica_location' => '0/D525E3A8' } }
    let(:block) { 10 }

    before do
      skip_feature_flags_yaml_validation
      skip_default_enabled_yaml_check
      allow(middleware).to receive(:clear)
      allow(Gitlab::Database::LoadBalancing::Session.current).to receive(:performed_write?).and_return(true)
    end

    context 'when worker class does not include ApplicationWorker' do
      let(:worker) { ActiveJob::QueueAdapters::SidekiqAdapter::JobWrapper.new }

      include_examples 'stick to the primary'
    end

    context 'when worker data consistency is :always' do
      include_context 'data consistency worker class', :always, :load_balancing_for_test_data_consistency_worker

      include_examples 'stick to the primary'
    end

    context 'when worker data consistency is :delayed' do
      include_examples 'sticks based on data consistency', :delayed

      context 'when replica is not up to date' do
        before do
          allow(::Gitlab::Database::LoadBalancing).to receive_message_chain(:proxy, :load_balancer, :release_host)
          allow(::Gitlab::Database::LoadBalancing).to receive_message_chain(:proxy, :load_balancer, :select_up_to_date_host).and_return(false)
        end

        around do |example|
          with_sidekiq_server_middleware do |chain|
            chain.add described_class
            Sidekiq::Testing.disable! { example.run }
          end
        end

        context 'when job is executed first' do
          it 'raise an error and retries', :aggregate_failures do
            expect do
              process_job(job)
            end.to raise_error(Sidekiq::JobRetry::Skip)

            expect(job['error_class']).to eq('Gitlab::Database::LoadBalancing::SidekiqServerMiddleware::JobReplicaNotUpToDate')
            expect(job[:database_chosen]).to eq('retry')
          end
        end

        context 'when job is retried' do
          it 'stick to the primary', :aggregate_failures do
            expect do
              process_job(job)
            end.to raise_error(Sidekiq::JobRetry::Skip)

            process_job(job)
            expect(job[:database_chosen]).to eq('primary')
          end
        end

        context 'replica selection mechanism feature flag rollout' do
          before do
            stub_feature_flags(sidekiq_load_balancing_rotate_up_to_date_replica: false)
          end

          it 'uses different implmentation' do
            expect(::Gitlab::Database::LoadBalancing).to receive_message_chain(:proxy, :load_balancer, :host, :caught_up?).and_return(false)

            expect do
              process_job(job)
            end.to raise_error(Sidekiq::JobRetry::Skip)
          end
        end
      end
    end

    context 'when worker data consistency is :sticky' do
      include_examples 'sticks based on data consistency', :sticky

      context 'when replica is not up to date' do
        before do
          allow(middleware).to receive(:replica_caught_up?).and_return(false)
        end

        include_examples 'stick to the primary'

        it 'updates job hash with primary database chosen', :aggregate_failures do
          expect { |b| middleware.call(worker, job, double(:queue), &b) }.to yield_control

          expect(job[:database_chosen]).to eq('primary')
        end
      end
    end
  end

  def process_job(job)
    Sidekiq::JobRetry.new.local(worker_class, job, queue) do
      worker_class.process_job(job)
    end
  end
end