qr.rb

class QrCodeController < ApplicationController
  include Magick

  def generate(issue_id, voucher_id)
    qrcode = RQRCode::QRCode.new("https://example.com/issues/#{issue_id}")

    # NOTE: showing with default options specified explicitly
    png = qrcode.as_png(
      bit_depth: 1,
      border_modules: 4,
      color_mode: ChunkyPNG::COLOR_GRAYSCALE,
      color: 'black',
      file: nil,
      fill: 'white',
      module_px_size: 6,
      resize_exactly_to: false,
      resize_gte_to: false,
      size: 170
    )

    IO.binwrite("public/images/voucher_#{voucher_id}.png", png.to_s)

    add_logo_and_text(issue_id, voucher_id)
  end

  def add_logo_and_text(issue_id, voucher_id)
    # now watermark with logo
    # magick composite -gravity center App_qr_icon_small.png li-source.png  final.png
    my_text = "#{Issue.find_by_id(issue_id).custom_field_value(67)} #{CustomField.find_by_id(67).name}"
    qr_image =  Image.read("public/images/voucher_#{voucher_id}.png")[0]
    logo_image = Image.read("plugins/qr_code/assets/images/shell_qr_logo.png")[0]
    image_with_logo = qr_image.composite( logo_image, CenterGravity, OverCompositeOp)

    draw = Magick::Draw.new
    draw.annotate(image_with_logo, 0, 0, 55, 3, my_text) do
     # self.font = Helvetica
     self.pointsize = 12
     self.font_weight = Magick::BoldWeight
     self.fill = "#000"
     self.gravity = Magick::SouthEastGravity
    end

    image_with_logo.write("public/images/voucher_#{voucher_id}.png")
  end
end