book_command.rb

class BookCommand < AppCommand

  def self.call args
    log :higher, "Called #{self}.#{__method__} with args #{args}"
    new(args).call
  end

  def initialize args
    @args = args
  end

  def call
    log :higher, "Called #{self}.#{__method__}"

    fname = "ruby.pdf"

    # path = "#{source_location_radical}/#{fname}"
    path = fname
    does_exist = File.exist? path

    log "#{path} does_exist? #{does_exist}"

    log "filtering"

    @count = 0

    # cover
    add_pages 0..1
    # title and authors
    add_pages 4
    # table of contents
    add_pages 6..8
    add_pages :maybe_add_blank
    # preface
    add_pages 10..13
    add_pages :maybe_add_blank
    # chapter 1
    add_pages 14..37
    add_pages :maybe_add_blank
    add_pages 38..44
    add_pages :maybe_add_blank
    add_pages 54..97
    add_pages :maybe_add_blank
    add_pages 98..129
    add_pages :maybe_add_blank
    add_pages 130..186
    add_pages :maybe_add_blank
    # chapter 6
    add_pages 188..225
    add_pages :maybe_add_blank
    add_pages 226..277
    add_pages :maybe_add_blank
    add_pages 278..315
    add_pages :maybe_add_blank
    add_pages 316..401
    add_pages :maybe_add_blank
    add_pages 402..425
    add_pages :maybe_add_blank
    # index
    add_pages 440..442
    add_pages 444

    # sudo rm /tmp/magick-*
    # ls -hla /tmp/magick-*

    d = 300
    log "convert -density #{d} #{fname}[#{@pages.join(",")}] ruby_final.pdf"

    log "filtered"
  end

  def blank
    9
  end

  def pages
    @pages ||= []
  end

  def add_pages x
    pages

    case x
    when Integer
      @pages.push x
      @count += 1
    when Range
      @pages.push "#{x.min}-#{x.max}"
      @count += 1+x.max-x.min
    when Symbol
      remainder = (@count - 2) % 4
      remainder.positive? and (remainder-4).times { add_pages blank }
    else
      raise "unrecognized type of #{x} : #{x.class}"
    end

  end

end