#
# shared tests for every storage plugin that can write and read back
#
# a test class includes StorageContract and implements
#   contract_storage(env, purpose) -> a new storage; purpose is :write or :read
# optionally
#   with_contract_env { |env| ... } -> environment per test (default: a tmp dir)
#   contract_rows(rows)             -> rows as the plugin reads them back (default: unchanged)
#
module StorageContract
  ROWS = [
    { 'id' => '1', 'code' => '007', 'name' => "O'Brien", 'note' => nil },
    { 'id' => '2', 'code' => '010', 'name' => 'Zürich | "ä", ß', 'note' => 'zwei' },
    { 'id' => '3', 'code' => '100', 'name' => 'drei', 'note' => '' }
  ].freeze

  def with_contract_env(&block) = with_tmpdir(&block)
  def contract_rows(rows) = rows

  def test_contract_write_and_read_back
    with_contract_env do |env|
      contract_storage(env, :write).tap { |s| s.write(ROWS) }.close
      reader = contract_storage(env, :read)
      assert_equal contract_rows(ROWS), reader.read
      reader.close
    end
  end

  def test_contract_write_row_and_read_with_block
    with_contract_env do |env|
      writer = contract_storage(env, :write)
      ROWS.each { |row| writer.write_row(row) }
      writer.close
      rows = []
      reader = contract_storage(env, :read)
      assert_nil reader.read { |row| rows << row }
      reader.close
      assert_equal contract_rows(ROWS), rows
    end
  end

  def test_contract_as_pipeline_source_and_target
    [false, true].each do |streamed|
      with_contract_env do |env|
        target = contract_storage(env, :write)
        stats = DataPipeline.new(streamed:) do
          logger PipelineHelper::QUIET
          read MemoryStorage.new(rows: ROWS)
          write target
        end.run
        assert_equal 3, stats.written

        source = contract_storage(env, :read)
        copy = MemoryStorage.new
        DataPipeline.new(streamed:) do
          logger PipelineHelper::QUIET
          read source
          write copy
        end.run
        assert_equal contract_rows(ROWS), copy.output, "streamed=#{streamed}"
      end
    end
  end

  def test_contract_close_twice
    with_contract_env do |env|
      storage = contract_storage(env, :write)
      storage.close
      storage.close
      pass
    end
  end
end