/* gcc -g -Wall -o server.exe server4.c */

#include <stdio.h>

#include <windows.h>
#include <process.h>


#define BUFSIZE 512

HANDLE objects[3];

typedef struct
{
  HANDLE pipe;
  HANDLE event_exit;
  OVERLAPPED ol;
  OVERLAPPED ol_read;
  DWORD read_count;
  int exit_thread;

  /* in normal struct */
  void *data;
  int size;
} Server;

void print_last_error(const char *fct);


static __stdcall unsigned int
_read_data_cb(void *data)
{
#define READ_BUFSIZE 5
  char buf[READ_BUFSIZE];
  Server *svr;
  DWORD ret;
  DWORD nbr_bytes;
  BOOL res;

  svr = (Server *)data;

  while (!svr->exit_thread)
    {
      ret = ReadFile(svr->pipe, buf, sizeof(buf), &nbr_bytes, &svr->ol_read);
      if (!ret)
        {
          DWORD err = GetLastError();
          if (err == ERROR_IO_PENDING)
            {
              /* Let's wait for the event to be signaled  ?? */
              /* Call GetOverlappedResult ?? */
            }
          else if (ret == ERROR_BROKEN_PIPE)
            {
              printf(" * broken pipe\n");
              SetEvent(svr->event_exit);
            }
          else
            {
              printf(" * unexpected error %ld\n", ret);
              SetEvent(svr->event_exit);
            }
        }
      else
        {
          printf(" * ReadFile : %ld\n", nbr_bytes);
        }
    }

  _endthreadex(0);
  return 0;
}

void print_last_error(const char *fct) 
{
  char *buf;
  DWORD dw = GetLastError(); 

  FormatMessage(FORMAT_MESSAGE_ALLOCATE_BUFFER | 
                FORMAT_MESSAGE_FROM_SYSTEM |
                FORMAT_MESSAGE_IGNORE_INSERTS,
                NULL,
                dw,
                MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
                (LPTSTR) &buf,
                0, NULL );

    // Display the error message and exit the process

  printf("%s failed with error %ld: %s\n", fct, dw, buf);
  LocalFree(buf); 
}

Server *
server_new(const char *name)
{
  char buf[256];
  Server *svr;
  HANDLE event;
  BOOL res;

  if (!name)
    return NULL;

  svr = (Server *)calloc(1,sizeof(Server));
  if (!svr)
    return NULL;

  snprintf(buf, sizeof(buf), "\\\\.\\pipe\\%s", name);

  /*
   * Asynchronuous
   * block mode
   */
  svr->pipe = CreateNamedPipe(buf,
                              PIPE_ACCESS_DUPLEX | FILE_FLAG_OVERLAPPED,
                              PIPE_TYPE_BYTE | PIPE_READMODE_BYTE | PIPE_WAIT,
                              PIPE_UNLIMITED_INSTANCES,
                              512, 512, 5000, NULL);
  if (!svr->pipe)
    {
      print_last_error("CreateNamedPipe");
      goto free_svr;
    }

  /*
   * Manual reset
   * Initial state : non signaled
   */
  event = CreateEvent(NULL, TRUE, FALSE, NULL);
  if (!event)
    {
      print_last_error("CreateEvent");
      goto close_pipe;
    }

  memset(&svr->ol, 0, sizeof(svr->ol));
  svr->ol.hEvent = event;

  res = ConnectNamedPipe(svr->pipe, &svr->ol);
  if (res)
    {
      print_last_error("ConnectNamedPipe");
      goto close_event;
    }
  else
    {
      DWORD err = GetLastError();

      if (err == ERROR_PIPE_CONNECTED)
        {
          SetEvent(svr->ol.hEvent);
          printf("client connected\n");
        }
      else if (err != ERROR_IO_PENDING)
        {
          print_last_error("ConnectNamedPipe");
          goto close_event;
        }
      /* else, we have ERROR_IO_PENDING, so a connection link is pending */
    }

  /*
   * Manual reset
   * Initial state : non signaled
   */
  svr->event_exit = CreateEvent(NULL, TRUE, FALSE, NULL);
  if (!svr->event_exit)
    {
      print_last_error("CreateEvent (event exit)");
      goto close_event;
    }

  /*
   * Manual reset
   * Initial state : non signaled
   */
  memset(&svr->ol_read, 0, sizeof(svr->ol_read));
  svr->ol_read.hEvent = CreateEvent(NULL, TRUE, FALSE, NULL);
  if (!svr->ol_read.hEvent)
    {
      print_last_error("CreateEvent (event exit)");
      goto close_event_exit;
    }

  /* start reading the pipe */
  objects[0] = event;
  objects[1] = svr->event_exit;
  objects[2] = svr->ol_read.hEvent;

  return svr;

 close_event_exit:
  CloseHandle(svr->event_exit);
 close_event:
  CloseHandle(event);
 close_pipe:
  CloseHandle(svr->pipe);
 free_svr:
  free(svr);

  return NULL;
}

void
server_del(Server *svr)
{
  if (!svr)
    return;

  CloseHandle(svr->event_exit);
  if (!FlushFileBuffers(svr->pipe))
    {
      print_last_error("FlushFileBuffers");
    }
  if (!DisconnectNamedPipe(svr->pipe))
    {
      print_last_error("DisconnectNamedPipe");
    }
  CloseHandle(svr->ol.hEvent);
  CloseHandle(svr->pipe);
  free(svr);
}

int main()
{
  Server *svr;
  DWORD ret;
  DWORD nbr_bytes;
  BOOL res;

  svr = server_new("toto");
  if (!svr)
    return -1;

  printf("waiting for client...\n");

  while (1)
    {
      ret = WaitForMultipleObjects(3, objects, FALSE, INFINITE);
      if (ret == WAIT_FAILED)
        {
          print_last_error("WaitForMultipleObjects");
          goto beach;
        }
      printf("WaitForMultipleObjects : %ld\n", ret);

      if (ret == WAIT_OBJECT_0)
        {
          ResetEvent(svr->ol.hEvent);

          res = GetOverlappedResult(svr->pipe, &svr->ol,
                                    &nbr_bytes, FALSE);
          if (!res)
            {
              print_last_error("GetOverlappedResult");

              if (!DisconnectNamedPipe(svr->pipe))
                {
                  print_last_error("DisconnectNamedPipe");
                  goto beach;
                }

              res = ConnectNamedPipe(svr->pipe, &svr->ol);
              if (res)
                {
                  print_last_error("ConnectNamedPipe");
                  goto beach;
                }
              else
                {
                  DWORD err = GetLastError();

                  if (err == ERROR_PIPE_CONNECTED)
                    {
                      SetEvent(svr->ol.hEvent);
                    }
                  else if (err != ERROR_IO_PENDING)
                    {
                      print_last_error("ConnectNamedPipe");
                      goto beach;
                    }
                  /* else, we have ERROR_IO_PENDING, so a connection link is pending */
                }
            }
          else
            {
              printf("client connected (%d)\n", res);

              /* read pipe */
              _beginthreadex(NULL, 0, _read_data_cb, svr, 0, NULL);
            }
        }
      if (ret == (WAIT_OBJECT_0 + 1))
        {
          printf("client connection closed\n");
          svr->exit_thread = 1;
          goto beach;
        }
      if (ret == (WAIT_OBJECT_0 + 2))
        {
          ResetEvent(svr->ol_read.hEvent);
          /* res = GetOverlappedResult(svr->pipe, &svr->ol_read, */
          /*                           &nbr_bytes, TRUE); */
          /* if (res) printf(" nbr bytes : %ld\n", nbr_bytes); */
          /* else */
          /*   print_last_error("GetOverlappedResult"); */
        }
    }

 beach:
  server_del(svr);

  return 0;
}