# frozen_string_literal: true

require 'fileutils'

RSpec.shared_examples 'can collect git garbage' do |update_statistics: true|
  include GitHelpers

  let!(:lease_uuid) { SecureRandom.uuid }
  let!(:lease_key) { "resource_housekeeping:#{resource.id}" }
  let(:params) { [resource.id, task, lease_key, lease_uuid] }
  let(:shell) { Gitlab::Shell.new }
  let(:repository) { resource.repository }
  let(:statistics_service_klass) { nil }

  subject { described_class.new }

  before do
    allow(subject).to receive(:find_resource).and_return(resource)
  end

  shared_examples 'it calls Gitaly' do
    let(:repository_service) { instance_double(Gitlab::GitalyClient::RepositoryService) }

    specify do
      expect_next_instance_of(Gitlab::GitalyClient::RepositoryService, repository.raw_repository) do |instance|
        expect(instance).to receive(:optimize_repository).and_call_original
      end

      subject.perform(*params)
    end

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

      specify do
        expect(subject).to receive(:get_gitaly_client).with(task, repository.raw_repository).and_return(repository_service)
        expect(repository_service).to receive(gitaly_task)

        subject.perform(*params)
      end
    end
  end

  shared_examples 'it updates the resource statistics' do
    it 'updates the resource statistics' do
      expect_next_instance_of(statistics_service_klass, anything, nil, statistics: statistics_keys) do |service|
        expect(service).to receive(:execute)
      end

      subject.perform(*params)
    end

    it 'does nothing if the database is read-only' do
      allow(Gitlab::Database).to receive(:read_only?) { true }

      expect(statistics_service_klass).not_to receive(:new)

      subject.perform(*params)
    end
  end

  describe '#perform', :aggregate_failures do
    let(:gitaly_task) { :garbage_collect }
    let(:task) { :gc }

    context 'with active lease_uuid' do
      before do
        allow(subject).to receive(:get_lease_uuid).and_return(lease_uuid)
      end

      it_behaves_like 'it calls Gitaly'
      it_behaves_like 'it updates the resource statistics' if update_statistics

      it "flushes ref caches when the task if 'gc'" do
        expect(subject).to receive(:renew_lease).with(lease_key, lease_uuid).and_call_original
        expect(repository).to receive(:expire_branches_cache).and_call_original
        expect(repository).to receive(:branch_names).and_call_original
        expect(repository).to receive(:has_visible_content?).and_call_original
        expect(repository.raw_repository).to receive(:has_visible_content?).and_call_original

        subject.perform(*params)
      end

      it 'handles gRPC errors' do
        repository_service = instance_double(Gitlab::GitalyClient::RepositoryService)

        allow_next_instance_of(Projects::GitDeduplicationService) do |instance|
          allow(instance).to receive(:execute)
        end

        allow(repository.raw_repository).to receive(:gitaly_repository_client).and_return(repository_service)
        allow(repository_service).to receive(:optimize_repository).and_raise(GRPC::NotFound)

        expect { subject.perform(*params) }.to raise_exception(Gitlab::Git::Repository::NoRepository)
      end

      context 'when optimized_housekeeping feature flag is disabled' do
        before do
          stub_feature_flags(optimized_housekeeping: false)
        end

        it 'handles gRPC errors' do
          allow_next_instance_of(Gitlab::GitalyClient::RepositoryService, repository.raw_repository) do |instance|
            allow(instance).to receive(:garbage_collect).and_raise(GRPC::NotFound)
          end

          expect { subject.perform(*params) }.to raise_exception(Gitlab::Git::Repository::NoRepository)
        end
      end
    end

    context 'with different lease than the active one' do
      before do
        allow(subject).to receive(:get_lease_uuid).and_return(SecureRandom.uuid)
      end

      it 'returns silently' do
        expect(repository).not_to receive(:expire_branches_cache).and_call_original
        expect(repository).not_to receive(:branch_names).and_call_original
        expect(repository).not_to receive(:has_visible_content?).and_call_original

        subject.perform(*params)
      end
    end

    context 'with no active lease' do
      let(:params) { [resource.id] }

      before do
        allow(subject).to receive(:get_lease_uuid).and_return(false)
      end

      context 'when is able to get the lease' do
        before do
          allow(subject).to receive(:try_obtain_lease).and_return(SecureRandom.uuid)
        end

        it_behaves_like 'it calls Gitaly'
        it_behaves_like 'it updates the resource statistics' if update_statistics

        it "flushes ref caches when the task if 'gc'" do
          expect(subject).to receive(:get_lease_uuid).with("git_gc:#{task}:#{expected_default_lease}").and_return(false)
          expect(repository).to receive(:expire_branches_cache).and_call_original
          expect(repository).to receive(:branch_names).and_call_original
          expect(repository).to receive(:has_visible_content?).and_call_original
          expect(repository.raw_repository).to receive(:has_visible_content?).and_call_original

          subject.perform(*params)
        end
      end

      context 'when no lease can be obtained' do
        it 'returns silently' do
          expect(subject).to receive(:try_obtain_lease).and_return(false)

          expect(subject).not_to receive(:command)
          expect(repository).not_to receive(:expire_branches_cache).and_call_original
          expect(repository).not_to receive(:branch_names).and_call_original
          expect(repository).not_to receive(:has_visible_content?).and_call_original

          subject.perform(*params)
        end
      end
    end

    context 'repack_full' do
      let(:task) { :full_repack }
      let(:gitaly_task) { :repack_full }

      before do
        expect(subject).to receive(:get_lease_uuid).and_return(lease_uuid)
      end

      it_behaves_like 'it calls Gitaly'
      it_behaves_like 'it updates the resource statistics' if update_statistics
    end

    context 'pack_refs' do
      let(:task) { :pack_refs }
      let(:gitaly_task) { :pack_refs }

      before do
        expect(subject).to receive(:get_lease_uuid).and_return(lease_uuid)
      end

      it_behaves_like 'it calls Gitaly' do
        let(:repository_service) { instance_double(Gitlab::GitalyClient::RefService) }
      end

      it 'does not update the resource statistics' do
        expect(statistics_service_klass).not_to receive(:new)

        subject.perform(*params)
      end
    end

    context 'repack_incremental' do
      let(:task) { :incremental_repack }
      let(:gitaly_task) { :repack_incremental }

      before do
        expect(subject).to receive(:get_lease_uuid).and_return(lease_uuid)
      end

      it_behaves_like 'it calls Gitaly'
      it_behaves_like 'it updates the resource statistics' if update_statistics
    end

    context 'prune' do
      before do
        expect(subject).to receive(:get_lease_uuid).and_return(lease_uuid)
      end

      specify do
        expect_next_instance_of(Gitlab::GitalyClient::RepositoryService, repository.raw_repository) do |instance|
          expect(instance).to receive(:prune_unreachable_objects).and_call_original
        end

        subject.perform(resource.id, 'prune', lease_key, lease_uuid)
      end
    end

    shared_examples 'gc tasks' do
      before do
        allow(subject).to receive(:get_lease_uuid).and_return(lease_uuid)
        allow(subject).to receive(:bitmaps_enabled?).and_return(bitmaps_enabled)

        stub_feature_flags(optimized_housekeeping: false)
      end

      it 'cleans up repository after finishing' do
        expect(resource).to receive(:cleanup).and_call_original

        subject.perform(resource.id, 'gc', lease_key, lease_uuid)
      end

      it 'prune calls garbage_collect with the option prune: true' do
        repository_service = instance_double(Gitlab::GitalyClient::RepositoryService)

        expect(subject).to receive(:get_gitaly_client).with(:prune, repository.raw_repository).and_return(repository_service)
        expect(repository_service).to receive(:garbage_collect).with(bitmaps_enabled, prune: true)

        subject.perform(resource.id, 'prune', lease_key, lease_uuid)
      end

      # Create a new commit on a random new branch
      def create_objects(resource)
        rugged = rugged_repo(resource.repository)
        old_commit = rugged.branches.first.target
        new_commit_sha = Rugged::Commit.create(
          rugged,
          message: "hello world #{SecureRandom.hex(6)}",
          author: { email: 'foo@bar', name: 'baz' },
          committer: { email: 'foo@bar', name: 'baz' },
          tree: old_commit.tree,
          parents: [old_commit]
        )
        rugged.references.create("refs/heads/#{SecureRandom.hex(6)}", new_commit_sha)
      end

      def packs(resource)
        Dir["#{path_to_repo}/objects/pack/*.pack"]
      end

      def packed_refs(resource)
        path = File.join(path_to_repo, 'packed-refs')
        FileUtils.touch(path)
        File.read(path)
      end

      def path_to_repo
        @path_to_repo ||= File.join(TestEnv.repos_path, resource.repository.relative_path)
      end

      def bitmap_path(pack)
        pack.sub(/\.pack\z/, '.bitmap')
      end
    end

    context 'with bitmaps enabled' do
      let(:bitmaps_enabled) { true }

      include_examples 'gc tasks'
    end

    context 'with bitmaps disabled' do
      let(:bitmaps_enabled) { false }

      include_examples 'gc tasks'
    end
  end
end