// In this benchmark, we connect a client to the server, and write
// as many bytes as we can in the specified time (default = 10s)
'use strict';

const common = require('../common.js');
const util = require('util');

// if there are dur=N and len=N args, then
// run the function with those settings.
// if not, then queue up a bunch of child processes.
const bench = common.createBenchmark(main, {
  len: [102400, 1024 * 1024 * 16],
  type: ['utf', 'asc', 'buf'],
  dur: [5]
});

const { TCP, constants: TCPConstants } = process.binding('tcp_wrap');
const TCPConnectWrap = process.binding('tcp_wrap').TCPConnectWrap;
const WriteWrap = process.binding('stream_wrap').WriteWrap;
const PORT = common.PORT;

function main({ dur, len, type }) {
  const serverHandle = new TCP(TCPConstants.SERVER);
  var err = serverHandle.bind('127.0.0.1', PORT);
  if (err)
    fail(err, 'bind');

  err = serverHandle.listen(511);
  if (err)
    fail(err, 'listen');

  serverHandle.onconnection = function(err, clientHandle) {
    if (err)
      fail(err, 'connect');

    var chunk;
    switch (type) {
      case 'buf':
        chunk = Buffer.alloc(len, 'x');
        break;
      case 'utf':
        chunk = 'ü'.repeat(len / 2);
        break;
      case 'asc':
        chunk = 'x'.repeat(len);
        break;
      default:
        throw new Error(`invalid type: ${type}`);
    }

    clientHandle.readStart();

    while (clientHandle.writeQueueSize === 0)
      write();

    function write() {
      const writeReq = new WriteWrap();
      writeReq.async = false;
      writeReq.oncomplete = afterWrite;
      var err;
      switch (type) {
        case 'buf':
          err = clientHandle.writeBuffer(writeReq, chunk);
          break;
        case 'utf':
          err = clientHandle.writeUtf8String(writeReq, chunk);
          break;
        case 'asc':
          err = clientHandle.writeAsciiString(writeReq, chunk);
          break;
      }

      if (err) {
        fail(err, 'write');
      } else if (!writeReq.async) {
        process.nextTick(function() {
          afterWrite(0, clientHandle);
        });
      }
    }

    function afterWrite(status, handle) {
      if (status)
        fail(status, 'write');

      while (clientHandle.writeQueueSize === 0)
        write();
    }
  };

  client(dur);
}

function fail(err, syscall) {
  throw util._errnoException(err, syscall);
}

function client(dur) {
  const clientHandle = new TCP(TCPConstants.SOCKET);
  const connectReq = new TCPConnectWrap();
  const err = clientHandle.connect(connectReq, '127.0.0.1', PORT);

  if (err)
    fail(err, 'connect');

  connectReq.oncomplete = function() {
    var bytes = 0;
    clientHandle.onread = function(nread, buffer) {
      // we're not expecting to ever get an EOF from the client.
      // just lots of data forever.
      if (nread < 0)
        fail(nread, 'read');

      // don't slice the buffer.  the point of this is to isolate, not
      // simulate real traffic.
      bytes += buffer.length;
    };

    clientHandle.readStart();

    // the meat of the benchmark is right here:
    bench.start();

    setTimeout(function() {
      // report in Gb/sec
      bench.end((bytes * 8) / (1024 * 1024 * 1024));
      process.exit(0);
    }, dur * 1000);
  };
}
