require 'prawn'

module Mork
  class SheetPDF < Prawn::Document
    def initialize(grid, info)
      @grid = grid
      @info = info
      super my_page_params
      registration_marks
      calibration_and_code @info[:code]
      header
      questions_and_choices
    end
    
    def my_page_params
      {
        page_size: @grid.pdf_page_size,
        margin: @grid.pdf_margins
      }
    end
    
    def registration_marks
      fill {
        @grid.pdf_reg_marks.each do |r|
          circle r[:p], r[:r]
        end
      }
    end
    
    def calibration_and_code(code)
      fill do
        # draw the dark calibration bar
        c = @grid.pdf_dark_calibration_area
        rectangle c[:p], c[:w], c[:h]
        # draw the bars corresponding to the code
        # least to most significant bit, left to right
        @grid.pdf_code_areas_for(code).each do |c|
          rectangle c[:p], c[:w], c[:h]
        end
      end
    end
    
    def header
      @info[:header].each do |k,v|
        text_box v, at:    @grid.pdf_header_xy(k),
                    width: @grid.pdf_header_width(k),
                    size:  @grid.pdf_header_size(k) || 12
      end
    end

    def questions_and_choices
      stroke do
        line_width 0.3
        nquestions.times do |q|
          fill_color "000000"
          text_box "#{q+1}", at: @grid.pdf_qnum_xy(q),
                             width: @grid.pdf_qnum_width,
                             align: :right,
                             size: Q_NUM_SIZE
          stroke_color "ff0000"
          font_size CH_LETTER_SZ
          nchoices(q).times do |c|
            a = @grid.pdf_choice_cell_area q, c
            rounded_rectangle a[:p], a[:w], a[:h], 2.mm
            fill_color "ff0000"
            draw_text (65+c).chr, at: @grid.pdf_choice_letter_xy(q, c)
          end
        end
      end
    end

    def save(fn)
      render_file fn
    end

  private
    def nquestions
      @info[:choices].length
    end

    def nchoices(i)
      @info[:choices][i]
    end
  end
end

class Fixnum
  def mm
    self * 2.83464566929134
  end
end

class Float
  def mm
    self * 2.83464566929134
  end
end