#!/usr/bin/env ruby

require 'trollop'


def main
  opts = Trollop::options do
    opt :foreign, "foreign file", :type => :string, :required => true
    opt :english, "english file", :type => :string, :required => true
    opt :size, "one size", :type => :int, :required => true
    opt :repeat, "number of repetitions", :type => :int, :default => 1
    opt :prefix, "prefix for output files", :type => :string
  end
  fn = opts[:foreign]
  fn_ext = fn.split('.').last
  f = File.new(fn, 'r').readlines
  en = opts[:english]
  en_ext = en.split('.').last
  e = File.new(en, 'r').readlines
  size = opts[:size]
  nlines_f = `wc -l #{fn}`.split()[0].to_i
  nlines_e = `wc -l #{en}`.split()[0].to_i
  if nlines_f!=nlines_e 
    STDERR.write "Unbalanced files (#{nlines_f} vs. #{nlines_e}), exiting!\n"
    exit 1
  end

  prefix = opts[:prefix]
  a = (0..nlines_e-1).to_a
  i = 0
  opts[:repeat].times {
    b = a.sample(size)
    ax = a.reject{|j| b.include? j}
    `mkdir split_#{i}`
    new_f = File.new "split_#{i}/#{prefix}.train.#{i}.#{fn_ext}", 'w+'
    new_e = File.new "split_#{i}/#{prefix}.train.#{i}.#{en_ext}", 'w+'
    ax.each { |j|
      new_f.write f[j]
      new_e.write e[j]
    }
    new_f.close; new_e.close
    new_f = File.new "split_#{i}/#{prefix}.test.#{i}.#{fn_ext}", 'w+'
    new_e = File.new "split_#{i}/#{prefix}.test.#{i}.#{en_ext}", 'w+'
    b.each { |j|
      new_f.write f[j]
      new_e.write e[j]
    }
    new_f.close; new_e.close
    i += 1
  }
end


main