var split = require('split'),
  Stream = require('stream'),
  duplex = require('duplexer');
  
  exports.parse = function protocol_parse(line) {
      var m = line.match(/^(:(\S+))?\s*([^:]\S+)\s+([^:]+)?(\s*:(.+))?/);
      var raw = m[0], source = m[2], cmd = m[3], 
      params = m[4], text = m[6];
      if (params) params = params.trim().split(' ');
      var target = params ? params[0] : null;
      var user = source ? source.match('(.+)!(.+)@(.+)') : null;
      return {
          raw: raw,
          source: source,
          cmd: cmd,
          user: user ? { 
              address: user[0], 
              nick: user[1], 
              user: user[2], 
              host: user[3] 
          } : null,
          params: params,
          target: target,
          text: text
      }
  }
  
  exports.construct = function protocol_construct(args) {
      args = [].slice.call(args);
      var last = args.length - 1;
      if (args[last] !== null)
          args[last] = ':' + args[last];
      else
          delete args[last];
      return args.join(' ') + '\n';
  }