prawn.rb

# -*- encoding: utf-8 -*-
class Certificate < Base
  class PDF
    PDF_OPTIONS = {
      :page_size   => "A5",
      :page_layout => :landscape,
      :background  => Rails.root.join("public/images/certificate/bg.png"),
      :margin      => [30, 70]
    }

    attr_accessor :subscription

    def initialize(subscription = nil)
      @subscription = subscription
    end

    def path
      File.join(root_dir, "#{subscription.uid}.pdf")
    end

    def root_dir
      File.join(AppConfig[:certificates_directory], "certificates")
    end

    def workshop
      subscription.workshop
    end

    def speaker
      workshop.speaker
    end

    def attendee
      subscription.user
    end

    def pdf
      Prawn::Document.new(PDF_OPTIONS) do |pdf|
        pdf.fill_color "40464e"
        pdf.text workshop.name, :size => 40, :style => :bold, :align => :center

        if workshop.tagline?
          pdf.move_up 10
          pdf.text workshop.tagline, :size => 16, :align => :center
        end

        pdf.move_down 30
        pdf.text "Certificado", :size => 24, :align => :center, :style => :bold

        pdf.move_down 30

        starts = I18n.l(workshop.starts_at, :format => :date)
        ends = I18n.l(workshop.ends_at, :format => :date)

        if starts != ends
          period = "de #{starts} a #{ends}"
        else
          period = "em #{starts}"
        end

        pdf.text "Certificamos que <b>#{attendee.name}</b> participou do workshop online “#{[workshop.name, workshop.tagline].compact.join(": ")}”, ministrado por #{speaker.name} e promovido pelo HOWTO, que aconteceu #{period}, com carga horária de #{workshop.workload} horas.", :inline_format => true

        pdf.move_down 15
        pdf.text "São Paulo, #{I18n.l(Time.now, :format => :short_date)}."

        pdf.move_down 30
        pdf.font Rails.root.join("public/rb.ttf").to_s
        pdf.text "howto", :size => 24

        pdf.move_up 5
        pdf.font "Helvetica"
        pdf.text "http://howtocode.com.br", :size => 10
      end
    end

    def save
      FileUtils.mkdir_p(root_dir)
      pdf.render_file(path)
      true
    end
  end
end