qr_segment.rb

module RQRCodeCore
  class QRSegment
    attr_reader :data, :mode

    def initialize(data:, mode: nil)
      @data = data
      if mode
        @mode = QRMODE_NAME[(mode || "").to_sym]
      else
        # If mode is not explicitely given choose mode according to data type
        @mode ||= if RQRCodeCore::QRNumeric.valid_data?(@data)
          QRMODE_NAME[:number]
        elsif QRAlphanumeric.valid_data?(@data)
          QRMODE_NAME[:alphanumeric]
        else
          QRMODE_NAME[:byte_8bit]
        end
      end
    end

    def bit_size
      chunk_size, bit_length, extra = case mode
      when :mode_number
        [3, QRNumeric::NUMBER_LENGTH[3], QRNumeric::NUMBER_LENGTH[data_length % 3] || 0]
      when :mode_alpha_numk
        [2, 11, 6]
      when :mode_8bit_byte
        [1, 8, 0]
      end

      (data_length / chunk_size) * bit_length + ((data_length % chunk_size) == 0 ? 0 : extra)
    end

    def writer
      case mode
      when :mode_number
        QRNumeric.new(data)
      when :mode_alpha_numk
        QRAlphanumeric.new(data)
      when :mode_multi
        QRMulti.new(data)
      else
        QR8bitByte.new(data)
      end
    end

    private

    def data_length
      data.length
    end
  end
end