# frozen_string_literal: true

require 'spec_helper'

RSpec.describe Gitlab::ObjectHierarchy do
  let_it_be(:parent, reload: true) { create(:group) }
  let_it_be(:child1) { create(:group, parent: parent) }
  let_it_be(:child2) { create(:group, parent: child1) }

  let(:options) { {} }

  shared_context 'Gitlab::ObjectHierarchy test cases' do
    describe '#base_and_ancestors' do
      let(:relation) do
        described_class.new(Group.where(id: child2.id), options: options).base_and_ancestors
      end

      it 'includes the base rows' do
        expect(relation).to include(child2)
      end

      it 'includes all of the ancestors' do
        expect(relation).to include(parent, child1)
      end

      it 'can find ancestors upto a certain level' do
        relation = described_class.new(Group.where(id: child2), options: options).base_and_ancestors(upto: child1)

        expect(relation).to contain_exactly(child2)
      end

      it 'uses ancestors_base #initialize argument' do
        relation = described_class.new(Group.where(id: child2.id), Group.none, options: options).base_and_ancestors

        expect(relation).to include(parent, child1, child2)
      end

      it 'does not allow the use of #update_all' do
        expect { relation.update_all(share_with_group_lock: false) }
          .to raise_error(ActiveRecord::ReadOnlyRecord)
      end

      describe 'hierarchy_order option' do
        let(:relation) do
          described_class.new(Group.where(id: child2.id), options: options).base_and_ancestors(hierarchy_order: hierarchy_order)
        end

        context ':asc' do
          let(:hierarchy_order) { :asc }

          it 'orders by child to parent' do
            expect(relation).to eq([child2, child1, parent])
          end
        end

        context ':desc' do
          let(:hierarchy_order) { :desc }

          it 'orders by parent to child' do
            expect(relation).to eq([parent, child1, child2])
          end
        end
      end
    end

    describe '#base_and_descendants' do
      let(:relation) do
        described_class.new(Group.where(id: parent.id), options: options).base_and_descendants
      end

      it 'includes the base rows' do
        expect(relation).to include(parent)
      end

      it 'includes all the descendants' do
        expect(relation).to include(child1, child2)
      end

      it 'uses descendants_base #initialize argument' do
        relation = described_class.new(Group.none, Group.where(id: parent.id), options: options).base_and_descendants

        expect(relation).to include(parent, child1, child2)
      end

      it 'does not allow the use of #update_all' do
        expect { relation.update_all(share_with_group_lock: false) }
          .to raise_error(ActiveRecord::ReadOnlyRecord)
      end

      context 'when with_depth is true' do
        let(:relation) do
          described_class.new(Group.where(id: parent.id), options: options).base_and_descendants(with_depth: true)
        end

        it 'includes depth in the results' do
          object_depths = {
            parent.id => 1,
            child1.id => 2,
            child2.id => 3
          }

          relation.each do |object|
            expect(object.depth).to eq(object_depths[object.id])
          end
        end
      end
    end

    describe '#descendants' do
      it 'includes only the descendants' do
        relation = described_class.new(Group.where(id: parent), options: options).descendants

        expect(relation).to contain_exactly(child1, child2)
      end
    end

    describe '#max_descendants_depth' do
      subject { described_class.new(base_relation, options: options).max_descendants_depth }

      context 'when base relation is empty' do
        let(:base_relation) { Group.where(id: nil) }

        it { expect(subject).to be_nil }
      end

      context 'when base has no children' do
        let(:base_relation) { Group.where(id: child2) }

        it { expect(subject).to eq(1) }
      end

      context 'when base has grandchildren' do
        let(:base_relation) { Group.where(id: parent) }

        it { expect(subject).to eq(3) }
      end
    end

    describe '#ancestors' do
      it 'includes only the ancestors' do
        relation = described_class.new(Group.where(id: child2), options: options).ancestors

        expect(relation).to contain_exactly(child1, parent)
      end

      it 'can find ancestors upto a certain level' do
        relation = described_class.new(Group.where(id: child2), options: options).ancestors(upto: child1)

        expect(relation).to be_empty
      end
    end

    describe '#all_objects' do
      let(:relation) do
        described_class.new(Group.where(id: child1.id), options: options).all_objects
      end

      it 'includes the base rows' do
        expect(relation).to include(child1)
      end

      it 'includes the ancestors' do
        expect(relation).to include(parent)
      end

      it 'includes the descendants' do
        expect(relation).to include(child2)
      end

      it 'uses ancestors_base #initialize argument for ancestors' do
        relation = described_class.new(Group.where(id: child1.id), Group.where(id: non_existing_record_id), options: options).all_objects

        expect(relation).to include(parent)
      end

      it 'uses descendants_base #initialize argument for descendants' do
        relation = described_class.new(Group.where(id: non_existing_record_id), Group.where(id: child1.id), options: options).all_objects

        expect(relation).to include(child2)
      end

      it 'does not allow the use of #update_all' do
        expect { relation.update_all(share_with_group_lock: false) }
          .to raise_error(ActiveRecord::ReadOnlyRecord)
      end
    end
  end

  context 'when the use_distinct_in_object_hierarchy feature flag is enabled' do
    before do
      stub_feature_flags(use_distinct_in_object_hierarchy: true)
      stub_feature_flags(use_distinct_for_all_object_hierarchy: false)
    end

    it_behaves_like 'Gitlab::ObjectHierarchy test cases'

    it 'calls DISTINCT' do
      expect(child2.self_and_ancestors.to_sql).to include("DISTINCT")
    end

    context 'when use_traversal_ids feature flag is enabled' do
      it 'does not call DISTINCT' do
        expect(parent.self_and_descendants.to_sql).not_to include("DISTINCT")
      end
    end

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

      it 'calls DISTINCT' do
        expect(parent.self_and_descendants.to_sql).to include("DISTINCT")
      end
    end
  end

  context 'when the use_distinct_for_all_object_hierarchy feature flag is enabled' do
    before do
      stub_feature_flags(use_distinct_in_object_hierarchy: false)
      stub_feature_flags(use_distinct_for_all_object_hierarchy: true)
    end

    it_behaves_like 'Gitlab::ObjectHierarchy test cases'

    it 'calls DISTINCT' do
      expect(child2.self_and_ancestors.to_sql).to include("DISTINCT")
    end

    context 'when use_traversal_ids feature flag is enabled' do
      it 'does not call DISTINCT' do
        expect(parent.self_and_descendants.to_sql).not_to include("DISTINCT")
      end
    end

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

      it 'calls DISTINCT' do
        expect(parent.self_and_descendants.to_sql).to include("DISTINCT")
      end

      context 'when the skip_ordering option is set' do
        let(:options) { { skip_ordering: true } }

        it_behaves_like 'Gitlab::ObjectHierarchy test cases'

        it 'does not include ROW_NUMBER()' do
          query = described_class.new(Group.where(id: parent.id), options: options).base_and_descendants.to_sql

          expect(query).to include("DISTINCT")
          expect(query).not_to include("ROW_NUMBER()")
        end
      end
    end
  end

  context 'when the use_distinct_in_object_hierarchy feature flag is disabled' do
    before do
      stub_feature_flags(use_distinct_in_object_hierarchy: false)
      stub_feature_flags(use_distinct_for_all_object_hierarchy: false)
    end

    it_behaves_like 'Gitlab::ObjectHierarchy test cases'

    it 'does not call DISTINCT' do
      expect(parent.self_and_descendants.to_sql).not_to include("DISTINCT")
      expect(child2.self_and_ancestors.to_sql).not_to include("DISTINCT")
    end
  end
end