require 'webrick'
require 'fileutils'

if ARGV.length != 0
   root = ARGV.first.gsub('\\', '/')
else
   root = '.'
end
BACKUP_DIR = 'bak'
BACKUP_VERSIONS = 3

module WEBrick
   module HTTPServlet

      class FileHandler
         alias do_PUT do_GET
      end

      class DefaultFileHandler
         def do_PUT(req, res)
            file = "#{@config[:DocumentRoot]}#{req.path}"
            res.body = ''
            unless Dir.exists? BACKUP_DIR
               Dir.mkdir BACKUP_DIR
            end
            FileUtils.cp(file, get_backup_filename("#{BACKUP_DIR}/#{File.basename(file, '.html')}"))
            File.open(file, "w+") {|f| f.puts(req.body)}
         end

         def do_OPTIONS(req, res)
            res['allow'] = "GET,HEAD,POST,OPTIONS,CONNECT,PUT,DAV,dav"
            res['x-api-access-type'] = 'file'
            res['dav'] = 'tw5/put'
         end

         def get_backup_filename(basename)
         (1..BACKUP_VERSIONS)
            .map {|i|
                  p = "#{basename}.#{i}.html"
                  d = File.exists?(p) ? File.mtime(p) : Time.at(0)
                  {"date" => d, "path" => p, "index" => i}}
            .sort_by {|f| [f['date'], f['index']]}[0]['path']
         end
      end
   end
end

server = WEBrick::HTTPServer.new({:Port => 8000, :DocumentRoot => root, :BindAddress => "127.0.0.1"})

trap "INT" do
   puts "Shutting down..."
   server.shutdown
end

server.start