#!/usr/bin/env ruby

require 'pp'

unless ARGV.size >= 1
  puts "Usage: ./demoer.rb demofile.demo [INDEX]"
  exit 1
end

demofile = ARGV[0]
index    = ARGV[1]

Section = Struct.new(:title, :contents)

sections  = []
header_re = /^=== (.*) ===$/
file = File.open(demofile)
file.each_line do |line|
  if header_re.match(line)
    title = $1
    sections.push Section.new(title, [])
  else
    sections.last.contents.push(line)
  end
end
file.close

if index
  index = index.to_i
  section = sections[index]
  puts section.title

  targetfile = demofile.sub(/\.demo$/, ".rb")
  target = File.new(targetfile, "w")

  section.contents.each do |line|
    target.write(line)
  end

  target.close
else
  sections.each_with_index do |section, index|
    puts "#{index}.) #{section.title}"
  end
end