/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements. See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership. The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License. You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied. See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */
#include <thrift/lib/cpp/test/loadgen/TerminalMonitor.h>

#include <unistd.h>
#include <sys/ioctl.h>

namespace apache { namespace thrift { namespace loadgen {

TerminalMonitor::TerminalMonitor()
  : screenHeight_(-1)
  , linesPrinted_(0) {
  // Determine the screen height
  screenHeight_ = getScreenHeight();
}

void TerminalMonitor::initializeInfo() {
  linesPrinted_ = printHeader();
}

void TerminalMonitor::redisplay(uint64_t intervalUsec) {
  // When the headers run off the top of the screen, reprint them
  if (screenHeight_ > 0 && linesPrinted_ > screenHeight_) {
    linesPrinted_ = printHeader();
  }

  linesPrinted_ += printInfo(intervalUsec);
}

int32_t TerminalMonitor::getScreenHeight() {
  if (!isatty(STDOUT_FILENO)) {
    return -1;
  }

  struct {
    uint16_t rows;
    uint16_t columns;
  } size;
  if (ioctl(STDOUT_FILENO, TIOCGWINSZ, &size) != 0) {
    return -1;
  }

  return size.rows;
}

}}} // apache::thrift::loadgen
