text: // Copyright (c) 2020 Uber Technologies, Inc.
  //
  // Permission is hereby granted, free of charge, to any person obtaining a copy
  // of this software and associated documentation files (the "Software"), to deal
  // in the Software without restriction, including without limitation the rights
  // to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  // copies of the Software, and to permit persons to whom the Software is
  // furnished to do so, subject to the following conditions:
  //
  // The above copyright notice and this permission notice shall be included in
  // all copies or substantial portions of the Software.
  //
  // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  // THE SOFTWARE.
  
  'use strict';
  
  var errors = require('./errors');
  var assert = require('assert');
  var ReadResult = require('bufrw').ReadResult;
  
  var readRes = new ReadResult();
  
  function TChannelServiceNameHandler(options) {
      if (!(this instanceof TChannelServiceNameHandler)) {
          return new TChannelServiceNameHandler(options);
      }
      var self = this;
  
      assert(typeof options === 'object', 'options required');
  
      self.channel = options.channel;
      assert(typeof self.channel === 'object', 'expected options.tchannel to be object');
  
      self.isBusy = options.isBusy || null;
      if (self.isBusy) {
          assert(typeof self.isBusy === 'function', 'expected options.isBusy to be function');
      }
  }
  
  TChannelServiceNameHandler.prototype.type = 'tchannel.service-name-handler';
  
  TChannelServiceNameHandler.prototype.handleLazily = function handleLazily(conn, reqFrame) {
      var self = this;
  
      var res = reqFrame.bodyRW.lazy.poolReadService(readRes, reqFrame);
      if (res.err) {
          // TODO: stat?
          self.channel.logger.warn('failed to lazy read frame serviceName', conn.extendLogInfo({
              error: res.err
          }));
          // TODO: protocol error instead?
          conn.sendLazyErrorFrameForReq(reqFrame, 'BadRequest', 'failed to read serviceName');
          return false;
      }
  
      var serviceName = res.value;
      if (!serviceName) {
          // TODO: reqFrame.extendLogInfo would be nice, especially if it added
          // things like callerName and arg1
          self.channel.logger.warn('missing service name in lazy frame', conn.extendLogInfo({}));
          conn.sendLazyErrorFrameForReq(reqFrame, 'BadRequest', 'missing serviceName');
          return false;
      }
  
      var chan = self.channel.subChannels[serviceName];
  
      if (chan && chan.handler.handleLazily) {
          return chan.handler.handleLazily(conn, reqFrame);
      } else {
          return false;
      }
  };
  
  TChannelServiceNameHandler.prototype.handleRequest = function handleRequest(req, buildRes) {
      var self = this;
  
      if (self.isBusy) {
          var busyInfo = self.isBusy(req);
          if (busyInfo) {
              buildRes().sendError('Busy', busyInfo);
              return;
          }
      }
  
      if (!req.serviceName) {
          buildRes().sendError('BadRequest', 'no service name given');
          return;
      }
      var chan = self.channel.subChannels[req.serviceName];
      if (chan) {
          chan.handler.handleRequest(req, buildRes);
      } else {
          self.handleDefault(req, buildRes);
      }
  };
  
  TChannelServiceNameHandler.prototype.handleDefault = function handleDefault(req, buildRes) {
      var err = errors.NoServiceHandlerError({serviceName: req.serviceName});
      buildRes().sendError('BadRequest', err.message);
  };
  
  TChannelServiceNameHandler.prototype.register = function register() {
      throw errors.TopLevelRegisterError();
  };
  
  module.exports = TChannelServiceNameHandler;
  