/* minazuki3.c - Don Yang (uguu.org)

   07/04/02
                                                                           */

#ifdef _WIN32
   #include<windows.h>
   #include<winsock.h>

   typedef SOCKET s;
   DWORD wthread;
   #define c closesocket
#else
   #include<pthread.h>
   #include<arpa/inet.h>
   #include<netinet/in.h>
   #include<sys/socket.h>
   #include<sys/time.h>
   #include<sys/types.h>
   #include<errno.h>
   #include<fcntl.h>
   #include<netdb.h>
   #include<signal.h>
   #include<unistd.h>

   typedef int s;
   pthread_t wthread;
   #define c close
#endif
#include<stdio.h>
#include<stdlib.h>
#include<string.h>

static int writer_active, size;
static s sock, s2;
static struct sockaddr_in a1, a2;
static fd_set sset, rset;
static struct hostent *hostinfo;
static unsigned short port = 0;
static char readbuffer[1025], writebuffer[1025];
struct timeval timeout;

static void createsocket(void)
{
   sock = socket(PF_INET, SOCK_STREAM, 0);
   a2.sin_family = AF_INET;
   a2.sin_port = htons(port);
   a2.sin_addr.s_addr = htonl(INADDR_ANY);
   if( bind(sock, (struct sockaddr*)&a2, sizeof(struct sockaddr_in)) == -1 )
   {
      puts("bind");
      sock = -1;
      return;
   }
}

#ifdef _WIN32
   static DWORD WINAPI write_loop(void *arg)
#else
   static void *write_loop(void *arg)
#endif
{
   writebuffer[1024] = '\0';
   while( writer_active )
   {
      printf("> ");
      fgets(writebuffer, 1024, stdin);
      if( feof(stdin) )
         break;
      send(sock, writebuffer, strlen(writebuffer), 0);
   }

   writer_active = 0;
   return 0;
}

int main(int argc, char **argv)
{
   #ifdef _WIN32
      WSADATA wsadata;
      if( WSAStartup(2, &wsadata) )
         return puts("WSAStartup");
   #endif

   if( argc < 3 )
      return printf("%s <remote host> <port>\n", *argv);

   if( (hostinfo = gethostbyname(argv[1])) == NULL )
   {
      if( (a1.sin_addr.s_addr = inet_addr(argv[1])) == INADDR_NONE )
         return puts("inet_addr");
   }
   else
   {
      a1.sin_addr = *(struct in_addr*)hostinfo->h_addr;
   }

   createsocket();
   if( sock == -1 )
      return 1;

   a1.sin_family = AF_INET;
   a1.sin_port = htons(port = (unsigned short)atoi(argv[2]));

   if( connect(sock, (struct sockaddr*)&a1, sizeof(struct sockaddr_in)) == -1 )
   {
      c(sock);
      createsocket();
      if( sock == -1 )
         return 1;
      if( listen(sock, 1) == -1 )
      {
         c(sock);
         return puts("listen");
      }

      FD_ZERO(&sset);
      FD_SET(sock, &sset);
      select(FD_SETSIZE, &sset, NULL, NULL, NULL);
      size = sizeof(struct sockaddr_in);
      s2 = accept(sock, (struct sockaddr*)&a1, &size);
      c(sock);
      if( s2 == -1 )
         return puts("accept");
      size = sizeof(struct sockaddr_in);
      getpeername(s2, (struct sockaddr*)&a1, &size);
      sock = s2;
   }

   printf("Connected to %s:%hd\n", inet_ntoa(a1.sin_addr), ntohs(a1.sin_port));

   writer_active = 1;

   #ifdef _WIN32
      CreateThread(NULL, 0, write_loop, NULL, 0, &wthread);
   #else
      pthread_create(&wthread, NULL, write_loop, NULL);
   #endif

   FD_ZERO(&sset);
   FD_SET(sock, &sset);
   while( writer_active )
   {
      memcpy(&rset, &sset, sizeof(fd_set));
      timeout.tv_sec = 1;
      timeout.tv_usec = 0;
      select(FD_SETSIZE, &rset, NULL, NULL, &timeout);
      if( FD_ISSET(sock, &rset) )
      {
         size = recv(sock, readbuffer, 1024, 0);
         if( size <= 0 )
         {
            writer_active = 0;
            break;
         }

         readbuffer[size] = '\0';
         printf("\r  \r%s> ", readbuffer);
         fflush(stdout);
      }
   }

   shutdown(sock, 2);
   c(sock);
   putchar('\n');

   #ifdef _WIN32
      WSACleanup();
   #endif
   return 0;
}