Modifies an ODT file, replacing occurrences of [[label]] with sequential numbers (one sequence per label)

enumerate-refs.rb

#!/usr/bin/env ruby
# enumerate-refs.rb
# Author: Rodrigo Rocha <[email protected]>
# Date: 2016-10-18

# To install the dependency, run on terminal:
# gem install rubyzip
require 'zip'

class Referencer; end

def help_and_quit
  puts '  Modifies an ODT file, replacing occurrences of [[label]]'
  puts 'with sequential numbers (one sequence per label).'
  puts '  Example: "See [[fig-overview]] and [[fig-detail]]"'
  puts 'becomes "See 1 and 2."'
  puts
  puts "Usage: #{$0} file.odt"
  exit 1
end

class Referencer
  def initialize
    @last_index = 0
    @hash = {}
  end

  def index_for(key)
    index = @hash[key]

    if index.nil?
      @last_index += 1
      @hash[key] = @last_index
      index = @last_index
    end

    index
  end
end

if __FILE__ == $0
  input_path = ARGV[0]
  help_and_quit if input_path.nil?

  referencer = Referencer.new

  Zip::File.open(input_path) do |zip_file|
    entry = zip_file.glob('content.xml').first
    contents = entry.get_input_stream.read

    contents.gsub!(/\[\[(.*?)\]\]/) do |m|
      key = $1.gsub(/<.*?>/, '').strip
      referencer.index_for(key)
    end

    zip_file.get_output_stream('content.xml'){ |f| f.write(contents) }

    zip_file.commit
  end
end