Contents

# frozen_string_literal: true

module Lcms
  module Engine
    class GenerateThumbnails
      attr_reader :resource

      MEDIAS = SocialThumbnail::MEDIAS.slice(1, 2) # to keep only (facebook pinterest)

      def initialize(resource)
        @resource = resource
        FileUtils.mkdir_p tmp_dir
      end

      def generate
        MEDIAS.each do |media|
          file_path = tmp_dir.join("#{resource_type}_#{resource.id}_#{media}.svg")
          # generate tmp svg file
          File.open(file_path, 'w') { |f| f.write(svg_content(media)) }
          # convert to png
          png_path = convert_to_png(file_path)

          # save thumbnail to s3
          thumb = SocialThumbnail.find_or_initialize_by(media: media.to_sym, target: resource)
          thumb.image = File.open(png_path)
          thumb.save
        end
        # clean tmp image files
        files = Dir.glob(tmp_dir.join "#{resource_type}_#{resource.id}_*.*")
        FileUtils.rm files
      end

      def tmp_dir
        Rails.root.join('tmp', 'svgs')
      end

      def resource_type
        resource.class.name.underscore
      end

      def svg_content(media)
        SVGSocialThumbnail.new(resource, media: media).render
      end

      def convert_to_png(file_path)
        tmp_path = file_path.to_s.gsub('.svg', '.tmp.png')
        png_path = file_path.to_s.gsub('.svg', '.png')
        `svgexport #{file_path} #{tmp_path}`
        `pngquant #{tmp_path} -o #{png_path} --speed=1 --force`
        png_path
      end
    end
  end
end

Version data entries

5 entries across 5 versions & 1 rubygems

Version	Path
lcms-engine-0.1.4	app/services/lcms/engine/generate_thumbnails.rb
lcms-engine-0.1.3	app/services/lcms/engine/generate_thumbnails.rb
lcms-engine-0.2.0	app/services/lcms/engine/generate_thumbnails.rb
lcms-engine-0.1.2	app/services/lcms/engine/generate_thumbnails.rb
lcms-engine-0.1.0	app/services/lcms/engine/generate_thumbnails.rb