require 'fileutils'

def create_permutations(input_file,output_dir)
  input_file_basename = File.basename(input_file,".wav")
  output_file = File.join(output_dir,File.basename(input_file_basename,".wav"))
  
  FileUtils.cp(input_file,output_file + ".original.wav")
  
  #create pitch shifted files
  system("sox '#{input_file}' '#{output_file}.one_semitone_up.wav' pitch 100")
  system("sox '#{input_file}' '#{output_file}.one_semitone_down.wav' pitch -100")
  system("sox '#{input_file}' '#{output_file}.two_semitones_up.wav' pitch 200")
  system("sox '#{input_file}' '#{output_file}.two_semitones_down.wav' pitch -200")
  
  #create faster and slower files
  system("sox '#{input_file}' '#{output_file}.10_percent_faster.wav' speed 1.10")
  system("sox '#{input_file}' '#{output_file}.10_percent_slower.wav' speed 0.90")
  system("sox '#{input_file}' '#{output_file}.20_percent_slower.wav' speed 0.80")
  system("sox '#{input_file}' '#{output_file}.20_percent_faster.wav' speed 1.20")

  #a reversed file
  system("sox '#{input_file}' '#{output_file}.reversed.wav' reverse")

  #crop a number of seconds from the beginning
  (10...65).step(5).each do |i|
    system("sox '#{input_file}' '#{output_file}.#{i}_sec_less.wav' trim #{i}")
  end

  #create white noise
  white_noise_file = "/tmp/#{input_file_basename}.white_noise.wav"
  system("sox '#{input_file}' '#{white_noise_file}' synth whitenoise" )
  #mix white noise with file
  (0.05...0.35).step(0.05).each do |i|
    system("sox -m '#{input_file}' -v #{i} '#{white_noise_file}' '#{output_file}_#{i}_white_noise.wav'")
  end	
end

glob_pattern = "/input_files/**/*.{wav}"
output_dir = "/fingerprinting_dataset"

FileUtils.mkdir_p(output_dir) unless File.exists? output_dir

Dir.glob(glob_pattern).delete_if{|i| i =~ /.*MR\..*/}.shuffle[0..100].each do |i|
  create_permutations(i,output_dir)
end