# frozen_string_literal: true

require 'spec_helper'

RSpec.describe DiffsMetadataEntity do
  let(:user) { create(:user) }
  let(:project) { create(:project, :repository) }
  let(:request) { EntityRequest.new(project: project, current_user: user) }
  let(:merge_request) { create(:merge_request_with_diffs, target_project: project, source_project: project) }
  let(:merge_request_diffs) { merge_request.merge_request_diffs }
  let(:merge_request_diff) { merge_request_diffs.last }
  let(:options) { {} }

  let(:entity) do
    described_class.new(
      merge_request_diff.diffs,
      options.merge(
        request: request,
        merge_request: merge_request,
        merge_request_diffs: merge_request_diffs
      )
    )
  end

  context 'as json' do
    subject { entity.as_json }

    it 'contain only required attributes' do
      expect(subject.keys).to contain_exactly(
        # Inherited attributes
        :real_size, :size, :branch_name,
        :target_branch_name, :commit, :merge_request_diff,
        :start_version, :latest_diff, :latest_version_path,
        :added_lines, :removed_lines, :render_overflow_warning,
        :email_patch_path, :plain_diff_path,
        :merge_request_diffs, :context_commits, :context_commits_diff,
        :definition_path_prefix, :source_branch_exists,
        :can_merge, :conflict_resolution_path, :has_conflicts,
        :project_name, :project_path, :user_full_name, :username,
        # Attributes
        :diff_files
      )
    end

    describe 'diff_files' do
      let!(:raw_diff_files) { merge_request_diff.diffs.raw_diff_files }

      before do
        expect_next_instance_of(Gitlab::Diff::FileCollection::MergeRequestDiff) do |instance|
          # Use lightweight version instead. Several methods delegate to it, so putting a 5
          # calls limit.
          expect(instance).to receive(:raw_diff_files).at_most(5).times.and_call_original
          expect(instance).not_to receive(:diff_files)
        end
      end

      it 'returns diff files metadata' do
        payload = DiffFileMetadataEntity.represent(raw_diff_files).as_json

        expect(subject[:diff_files]).to eq(payload)
      end

      context 'when merge_ref_head_diff and allow_tree_conflicts options are set' do
        let(:conflict_file) { double(path: raw_diff_files.first.new_path, conflict_type: :both_modified) }
        let(:conflicts) { double(conflicts: double(files: [conflict_file]), can_be_resolved_in_ui?: false) }

        before do
          allow(merge_request).to receive(:cannot_be_merged?).and_return(true)
          allow(MergeRequests::Conflicts::ListService).to receive(:new).and_return(conflicts)
        end

        context 'when merge_ref_head_diff is true and allow_tree_conflicts is false' do
          let(:options) { { merge_ref_head_diff: true, allow_tree_conflicts: false } }

          it 'returns diff files metadata without conflicts' do
            payload = DiffFileMetadataEntity.represent(raw_diff_files).as_json

            expect(subject[:diff_files]).to eq(payload)
          end
        end

        context 'when merge_ref_head_diff is false and allow_tree_conflicts is true' do
          let(:options) { { merge_ref_head_diff: false, allow_tree_conflicts: true } }

          it 'returns diff files metadata without conflicts' do
            payload = DiffFileMetadataEntity.represent(raw_diff_files).as_json

            expect(subject[:diff_files]).to eq(payload)
          end
        end

        context 'when merge_ref_head_diff and allow_tree_conflicts are true' do
          let(:options) { { merge_ref_head_diff: true, allow_tree_conflicts: true } }

          it 'returns diff files metadata with conflicts' do
            payload = DiffFileMetadataEntity.represent(raw_diff_files, conflicts: { conflict_file.path => conflict_file }).as_json

            expect(subject[:diff_files]).to eq(payload)
          end
        end
      end
    end
  end
end