require "support/test_class"
require "support/association_test_class"

RSpec.shared_examples ".order_as_specified" do
  # Clean up after each test. This is a lot lighter for these few tests than
  # trying to wrangle with RSpec-Rails to get transactional tests to work.
  after :each do
    TestClass.delete_all
    AssociationTestClass.delete_all
  end

  let(:shuffled_objects) do
    5.times.map { |i| TestClass.create(field: "Field #{i}") }.shuffle
  end
  let(:shuffled_object_fields) { shuffled_objects.map(&:field) }
  let(:shuffled_object_ids) { shuffled_objects.map(&:id) }
  let(:omitted_object) { TestClass.create(field: "Nothing") }

  context "with no table name specified" do
    subject { TestClass.order_as_specified(field: shuffled_object_fields) }

    it "returns results including unspecified objects" do
      omitted_object # Build an object that isn't sorted in this list.
      expect(subject).to include omitted_object
    end

    it "returns results in the given order" do
      omitted_object # Build an object that isn't sorted in this list.
      expect(subject.map(&:id)).
        to eq [*shuffled_object_ids, omitted_object.id]
    end

    context "when the order includes nil" do
      let(:shuffled_objects) do
        5.times.map do |i|
          TestClass.create(field: (i == 0 ? nil : "Field #{i}"))
        end.shuffle
      end

      it "raises an error" do
        expect { subject }.to raise_error(OrderAsSpecified::Error)
      end
    end
  end

  context "with another table name specified" do
    subject do
      TestClass.
        joins(:association_test_class).
        order_as_specified(
          association_test_classes: { id: associated_object_ids }
        )
    end

    let(:associated_objects) do
      shuffled_objects.map do |object|
        AssociationTestClass.create(test_class: object)
      end
    end
    let(:associated_object_ids) { associated_objects.map(&:id) }
    let(:omitted_associated_object) do
      AssociationTestClass.create(test_class: omitted_object)
    end

    it "returns results including unspecified objects" do
      # Build an object that isn't sorted in this list.
      omitted_associated_object

      expect(subject).to include omitted_object
    end

    it "returns results in the given order" do
      # Build an object that isn't sorted in this list.
      omitted_associated_object

      expect(subject.map(&:id)).
        to eq [*shuffled_object_ids, omitted_object.id]
    end
  end
end