/* gcc -g -Wall -o server.exe server5.c */

#include <stdio.h>

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


#define BUFSIZE 512

HANDLE objects[2];

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

  HANDLE iocp_read;

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

void print_last_error(const char *fct);

static void
_svr_data_append(Server *svr, void *data, size_t size)
{
  if (!svr->data)
    {
      svr->data = malloc(size);
      if (!svr->data)
        return;
      memcpy(svr->data, data, size);
      svr->size = size;
    }
  else
    {
      void *tmp;
      tmp = realloc(svr->data, svr->size + size);
      if (tmp)
        {
          svr->data = tmp;
          memcpy(svr->data + svr->size, data, size);
          svr->size += size;
        }
    }

  {
    char *buf;
    buf = malloc(svr->size + 1);
    memcpy(buf, svr->data, svr->size);
    buf[svr->size] = 0;
    printf("msg (%d -> %02d) : %s\n", (int)size, (int)svr->size, buf);
    free(buf);
  }
}

static unsigned int __stdcall
_read_data_cb(void *data)
{
#define READ_BUFSIZE 5
  char buf[READ_BUFSIZE];
  Server *svr;
  DWORD nbr_bytes = 0;
  BOOL res;
  BOOL pending = FALSE;

  ULONG_PTR key;
  LPOVERLAPPED lpol;

  svr = (Server *)data;

  while (!svr->exit_thread)
    {
      res = ReadFile(svr->pipe, buf, sizeof(buf),
                     &nbr_bytes, &svr->ol_read);
      if (res)
        {

          printf("ReadFile 1\n");
          _svr_data_append(svr, buf, nbr_bytes);
          do {
            res = ReadFile(svr->pipe, buf, sizeof(buf),
                           &nbr_bytes, &svr->ol_read);
            if (res)
              {
                printf("ReadFile 2\n");
                _svr_data_append(svr, buf, nbr_bytes);
              }
            else
              {
                DWORD err = GetLastError();
                if (err == ERROR_IO_PENDING)
                  {
                    printf("ReadFile2: ERROR_IO_PENDING\n");
                    pending = TRUE;
                  }
                else if (err == ERROR_SUCCESS)
                  {
                    printf(" * success\n");
                    continue;
                  }
                else if (err == ERROR_BROKEN_PIPE)
                  {
                    printf(" * broken pipe\n");
                    SetEvent(svr->event_exit);
                  }
                else
                  {
                    printf(" * unexpected error %ld\n", err);
                    SetEvent(svr->event_exit);
                  }
                break;
              }
          } while (1);
        }
      else
        {
          DWORD err = GetLastError();
          if (err == ERROR_IO_PENDING)
            {
              printf("ReadFile1: ERROR_IO_PENDING\n");
              pending = TRUE;
            }
          else if (err == ERROR_SUCCESS)
            {
              printf(" * success\n");
              continue;
            }
          else if (err == ERROR_BROKEN_PIPE)
            {
              printf(" * broken pipe\n");
              SetEvent(svr->event_exit);
            }
          else
            {
              printf(" * unexpected error %ld\n", err);
              SetEvent(svr->event_exit);
            }
        }

      if (pending)
        {
          res = GetQueuedCompletionStatus(svr->iocp_read, &nbr_bytes, &key, &lpol, INFINITE);
          printf("GQCIOS %d %d %p\n", (int)nbr_bytes, (int)key, lpol);
          if (res && lpol)
            {
              res = ReadFile(svr->pipe, buf, sizeof(buf),
                             &nbr_bytes, &svr->ol_read);
              if (res)
                {
                  pending = FALSE;
                  printf("ReadFile 3\n");
                  _svr_data_append(svr, buf, nbr_bytes);
                }
              else
                {
                  DWORD err = GetLastError();
                if (err == ERROR_IO_PENDING)
                  {
                    printf("ReadFile3: ERROR_IO_PENDING\n");
                  }
                }
            }
          else
            {
              DWORD err = GetLastError();
              print_last_error("GetQueuedCompletionStatus");
              if (err == ERROR_IO_PENDING)
                {
                  pending = TRUE;
                }
            }
        }
    }

  printf("ending thread...\n");

  _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;

  HANDLE iocp;
  ULONG_PTR key = 0xff;

  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;
    }

  /*
   * ConnectNamedPipe() event
   * 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;
  objects[0] = svr->ol.hEvent;

  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 */
    }

  /*
   * Exit event
   * Manual reset
   * Initial state : non signaled
   */
  event = CreateEvent(NULL, TRUE, FALSE, NULL);
  if (!event)
    {
      print_last_error("CreateEvent (event exit)");
      goto close_event;
    }
  svr->event_exit = event;
  objects[1] = svr->event_exit;

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

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

  iocp = CreateIoCompletionPort(INVALID_HANDLE_VALUE, NULL, 0, 0);
  if (!iocp)
    {
      print_last_error("CreateIoCompletionPort");
      goto close_event_exit;
    }

  svr->iocp_read = CreateIoCompletionPort(svr->pipe, iocp, key, 1);
  if (!svr->iocp_read)
    {
      print_last_error("CreateIoCompletionPort");
      goto close_event_exit;
    }

  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(2, 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))
        {
        }
    }

 beach:
  server_del(svr);

  return 0;
}