module SmartS3Sync

# File lib/smart_s3_sync.rb, line 9
def self.sync(dir, remote_dir, connection_options, remote_prefix=nil, sync_options={})
  table = FileTable.new(dir, remote_prefix)

  bucket = Fog::Storage.new(connection_options).directories.
    get(remote_dir, {:prefix => remote_prefix})

  # Add all files in the cloud to our map.
  $stderr.print "Checking Files: "
  checked = 0
  bucket.files.each do |file|
    table.push(file)
    if $stderr.tty?
      $stderr.print "\b" * checked.to_s.length unless checked == 0
      $stderr.print (checked += 1).to_s
    elsif (checked += 1) == 1
      $stderr.print '...'
    elsif checked % 1000 == 0
      $stderr.print '.'
    end
  end

  $stderr.puts " done! (#{checked} files)\n"
  $stderr.puts "Status: Need to download #{table.to_download.length} files (#{table.to_download.map(&:size).inject(&:+)} bytes)"
  $stderr.puts "Status: with an effective total of #{table.to_copy.inject(0){|coll, obj| coll + obj.destinations.length }} files (#{table.to_copy.map{|x| x.size * x.destinations.length }.inject(&:+)} bytes)"

  # And copy them to the right places
  table.copy!(bucket, sync_options)

  # sweep through and remove all files not in the cloud
  Dir.glob(File.join(dir, '**/*')) do |file|
    if !File.directory?(file)
      File.unlink(file) and $stderr.puts "DELETING: #{file}" unless table.keep?(file)
    end
  end

  # and then all empty directories
  Dir.glob(File.join(dir, '**/*')) do |file|
    if File.directory?(file) && Dir.entries(file).length == 0
      $stderr.puts "DELETING: #{file}"
      Dir.rmdir(file)
    end
  end
end