# frozen_string_literal: true

require 'spec_helper'

RSpec.describe BulkImports::FileDecompressionService, feature_category: :importers do
  using RSpec::Parameterized::TableSyntax

  let_it_be(:tmpdir) { Dir.mktmpdir }
  let_it_be(:ndjson_filename) { 'labels.ndjson' }
  let_it_be(:ndjson_filepath) { File.join(tmpdir, ndjson_filename) }
  let_it_be(:gz_filename) { "#{ndjson_filename}.gz" }
  let_it_be(:gz_filepath) { "spec/fixtures/bulk_imports/gz/#{gz_filename}" }

  before do
    FileUtils.copy_file(gz_filepath, File.join(tmpdir, gz_filename))
    FileUtils.remove_entry(ndjson_filepath) if File.exist?(ndjson_filepath)
  end

  after(:all) do
    FileUtils.remove_entry(tmpdir)
  end

  subject { described_class.new(tmpdir: tmpdir, filename: gz_filename) }

  describe '#execute' do
    it 'decompresses specified file' do
      subject.execute

      expect(File.exist?(File.join(tmpdir, ndjson_filename))).to eq(true)
      expect(File.open(ndjson_filepath, &:readline)).to include('title', 'description')
    end

    context 'when validate_import_decompressed_archive_size feature flag is enabled' do
      before do
        stub_feature_flags(validate_import_decompressed_archive_size: true)
      end

      it 'performs decompressed file size validation' do
        expect_next_instance_of(Gitlab::ImportExport::DecompressedArchiveSizeValidator) do |validator|
          expect(validator).to receive(:valid?).and_return(true)
        end

        subject.execute
      end
    end

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

      it 'does not perform decompressed file size validation' do
        expect(Gitlab::ImportExport::DecompressedArchiveSizeValidator).not_to receive(:new)

        subject.execute
      end
    end

    context 'when dir is not in tmpdir' do
      subject { described_class.new(tmpdir: '/etc', filename: 'filename') }

      it 'raises an error' do
        expect { subject.execute }.to raise_error(StandardError, 'path /etc is not allowed')
      end
    end

    context 'when path is being traversed' do
      subject { described_class.new(tmpdir: File.join(Dir.mktmpdir, 'test', '..'), filename: 'filename') }

      it 'raises an error' do
        expect { subject.execute }.to raise_error(Gitlab::Utils::PathTraversalAttackError, 'Invalid path')
      end
    end

    shared_examples 'raises an error and removes the file' do |error_message:|
      specify do
        expect { subject.execute }
          .to raise_error(BulkImports::FileDecompressionService::ServiceError, error_message)
        expect(File).not_to exist(file)
      end
    end

    shared_context 'when compressed file' do
      let_it_be(:file) { File.join(tmpdir, 'file.gz') }

      subject { described_class.new(tmpdir: tmpdir, filename: 'file.gz') }

      before do
        FileUtils.send(link_method, File.join(tmpdir, gz_filename), file)
      end
    end

    shared_context 'when decompressed file' do
      let_it_be(:file) { File.join(tmpdir, 'file.txt') }

      subject { described_class.new(tmpdir: tmpdir, filename: gz_filename) }

      before do
        original_file = File.join(tmpdir, 'original_file.txt')
        FileUtils.touch(original_file)
        FileUtils.send(link_method, original_file, file)

        subject.instance_variable_set(:@decompressed_filepath, file)
      end
    end

    context 'when compressed file is a symlink' do
      let(:link_method) { :symlink }

      include_context 'when compressed file'

      include_examples 'raises an error and removes the file', error_message: 'File decompression error'
    end

    context 'when compressed file shares multiple hard links' do
      let(:link_method) { :link }

      include_context 'when compressed file'

      include_examples 'raises an error and removes the file', error_message: 'File decompression error'
    end

    context 'when decompressed file is a symlink' do
      let(:link_method) { :symlink }

      include_context 'when decompressed file'

      include_examples 'raises an error and removes the file', error_message: 'Invalid file'
    end

    context 'when decompressed file shares multiple hard links' do
      let(:link_method) { :link }

      include_context 'when decompressed file'

      include_examples 'raises an error and removes the file', error_message: 'Invalid file'
    end
  end
end