require 'find'

module MP3Manager
  VERSION = '1.0.0'
  SIXTY_DAYS_IN_SECONDS = 5184000
  def MP3Manager.create_m3u_playlist(m3u_file, folder = '.', new_files_only = false, relative = true, verbose = true)
    if m3u_file.kind_of?(String)
      if File::exists?(m3u_file)
        puts "#{m3u_file} exists.. overwriting"
        #prompt = STDIN::gets
        #if not(prompt.index(%r{^y}i)) : puts "Exiting.."; return; end
      end
      # open a new file object as m3u_file - we will pass this down the recursion chain, allowing us to write to this file from any folder
      if verbose : puts "Using playlist file #{m3u_file}"; end
      m3u_file = File::open(m3u_file, 'w+')
    end
    
    folder = File::join(folder)
    
    m3u_filename = m3u_file.path
    # normalize path with to unix style
    m3u_filename.gsub!('\\', '/')
    
    m3u_file_contents = Array.new
    # iterate through all files and subfolders
    Find.find(folder) do |file|
      # normalize path to unix style
      file.gsub!('\\', '/')
      case
        when File::file?(file)
          # if we are only interested in new files, then skip this file if it's datetime is older than 60 days
          if new_files_only
            if File::mtime(file) < (Time::now - SIXTY_DAYS_IN_SECONDS) : next; end
          end
          # make path relative for current file, if appropriate
          if relative
            if File::dirname(m3u_filename) != '.'
              file.gsub!(%r{^#{File::dirname(m3u_filename)}}i, "")
            end
            file.gsub!(%r{^/}, "")
          end
          # only process mp3 files
          if File::extname(file) == '.mp3'
            m3u_file_contents << file
          end
        when File::directory?(file)
          if verbose : puts "Processing folder #{file}"; end
      end
    end
    #sort using case independent method
    sorted_contents = m3u_file_contents.sort_by {|w| w.downcase}
    m3u_file.puts(sorted_contents.uniq.join("\n"))
  end
end


if !ARGV[0] || !ARGV[1] || ARGV[0].index(%r{help$|\?$})
  puts "Usage: m3umaker.rb (m3u file to create) (folder to process) /new"
else
  if ARGV[2] && ARGV[2].downcase =~ /new$/i : new_files_only = true; end
  MP3Manager::create_m3u_playlist(ARGV[0], ARGV[1], new_files_only)
end