/**
 *  @file stdiodevice.cc
 *  @brief Implementation of the StdIODevice class
 *  @author Andreas Aardal Hanssen
 *  @date 2003/2023
 */

#include "stdiodevice.h"

#include <string>

#include <errno.h>

#include <sys/ioctl.h>
#include <sys/select.h>
#include <sys/time.h>
#include <sys/types.h>
#include <unistd.h>

using namespace Binc;

StdIODevice::StdIODevice(int f) : IODevice(f) {}

StdIODevice::~StdIODevice() {}

std::string StdIODevice::service() const
{
  return "client";
}

bool StdIODevice::canRead() const
{
  size_t bytes;
  return ioctl(fileno(stdin), FIONREAD, (char *)&bytes) > 0;
}

bool StdIODevice::waitForWrite() const
{
  fd_set writeMask;
  FD_ZERO(&writeMask);
  FD_SET(fileno(stdout), &writeMask);

  struct timeval tv;
  tv.tv_sec = timeout;
  tv.tv_usec = 0;

  int result = select(fileno(stdout) + 1,
                      nullptr,
                      &writeMask,
                      nullptr,
                      timeout ? &tv : nullptr);
  if (result == 0) error = Error::Timeout;
  return result > 0;
}

bool StdIODevice::waitForRead() const
{
  fd_set readMask;
  FD_ZERO(&readMask);
  FD_SET(fileno(stdin), &readMask);

  struct timeval tv;
  tv.tv_sec = timeout;
  tv.tv_usec = 0;

  int result = select(fileno(stdin) + 1, &readMask, nullptr, nullptr, timeout ? &tv : nullptr);
  if (result == 0) error = Error::Timeout;
  return result > 0;
}

IODevice::WriteResult StdIODevice::write()
{
  for (;;) {
    ssize_t wrote = ::write(fileno(stdout),
                            outputBuffer.str().c_str(),
                            outputBuffer.getSize());

    if (wrote == -1) {
      if (errno == EINTR)
        continue;
      else
        return WriteError;
    }

    outputBuffer.popString(wrote);

    if (wrote == (ssize_t)outputBuffer.getSize()) return WriteDone;
    return WriteWait;
  }
}

bool StdIODevice::fillInputBuffer()
{
  if (!waitForRead()) return false;

  char buf[4096];
  ssize_t red = read(fileno(stdin), buf, sizeof(buf) - 1);
  if (red <= 0) return false;

  buf[red] = '\0';
  inputBuffer << buf;
  return true;
}