#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <errno.h>
#include <fcntl.h>
#include <stdarg.h>

#include "E-ScreenShoot_ftp.h"

int                 ftp_connected;
int                 ftp_debug;

static int          ftp_pty, ftp_pid;
static char         tty_name[32];

static void         ftp_send(int argc, ...);
static int          ftp_recv(void);

static int
open_pty(void)
{
#ifdef HAVE_GETPT
   int                 master;
   char               *slave;

   if (-1 == (master = getpt()))
      return -1;
   if (-1 == grantpt(master) || -1 == unlockpt(master)
       || !(slave = ptsname(master)))
     {
	close(master);
	return -1;
     }
   strcpy(tty_name, slave);
   return master;
#else
   static char         pty_name[32];
   static char         s1[] = "pqrs";
   static char         s2[] = "0123456789abcdef";

   char               *p1, *p2;
   int                 pty;

   for (p1 = s1; *p1; p1++)
     {
	for (p2 = s2; *p2; p2++)
	  {
	     sprintf(pty_name, "/dev/pty%c%c", *p1, *p2);
	     sprintf(tty_name, "/dev/tty%c%c", *p1, *p2);
	     if (-1 == access(tty_name, R_OK | W_OK))
		continue;
	     if (-1 != (pty = open(pty_name, O_RDWR)))
		return pty;
	  }
     }
   return -1;
#endif
}

void
ftp_init(int passive)
{
   static char        *argv[] = { (char *)"ftp", (char *)"-n", NULL };

   if (-1 == (ftp_pty = open_pty()))
     {
	fprintf(stderr, "can't grab pty\n");
	exit(1);
     }
   switch (ftp_pid = fork())
     {
     case -1:
	perror("fork");
	exit(1);
     case 0:
	/* child */
	close(ftp_pty);
	close(0);
	close(1);
	close(2);
	setsid();
	open(tty_name, O_RDWR);
	dup(0);
	dup(0);
	unsetenv("LANG");	/* need english messages from ftp */
	execvp(argv[0], argv);
	perror("execvp");
	exit(1);
     default:
	/* parent */
	break;
     }
   ftp_recv();

   /* initialisation */
   if (passive)
     {
	ftp_send(1, "pass");
	ftp_recv();
     }
}

void
ftp_send(int argc, ...)
{
   va_list             ap;
   char                line[256], *arg;
   int                 length, i;

   va_start(ap, argc);
   memset(line, 0, 256);
   length = 0;
   for (i = 0; i < argc; i++)
     {
	if (i)
	   line[length++] = ' ';
	arg = va_arg(ap, char *);

	length += strlen(arg);
	strcat(line, arg);
     }
   line[length++] = '\n';
   va_end(ap);

   if (ftp_debug)
      fprintf(stderr, ">> %s", line);
   if (length != write(ftp_pty, line, length))
     {
	fprintf(stderr, "ftp: write error\n");
	exit(1);
     }
}

int
ftp_recv()
{
   char                line[512], *p, *n;
   int                 length, done, status, ret = 0;
   fd_set              set;

   for (done = 0; !done;)
     {
	FD_ZERO(&set);
	FD_SET(ftp_pty, &set);
	select(ftp_pty + 1, &set, NULL, NULL, NULL);

	switch (length = read(ftp_pty, line, 511))
	  {
	  case -1:
	     perror("ftp: read error");
	     exit(1);
	  case 0:
	     fprintf(stderr, "ftp: EOF\n");
	     exit(1);
	  }
	line[length] = 0;

	for (p = line; p && *p; p = n)
	  {
	     /* split into lines */
	     if ((n = strchr(p, '\n')) || (n = strchr(p, '\r')))
		*(n++) = 0;
	     else
		n = NULL;
	     if (ftp_debug)
		fprintf(stderr, "<< %s\n", p);

	     /* prompt? */
	     if (strstr(p, "ftp>"))
	       {
		  done = 1;
	       }

	     /* line dropped ? */
	     if (strstr(p, "closed connection"))
	       {
		  fprintf(stderr, "ftp: lost connection\n");
		  ftp_connected = 0;
	       }
	     if (strstr(p, "Not connected"))
	       {
		  if (ftp_connected)
		     fprintf(stderr, "ftp: lost connection\n");
		  ftp_connected = 0;
	       }

	     /* status? */
	     if (1 == sscanf(p, "%d", &status))
	       {
		  ret = status;
	       }
	  }
     }
   return ret;
}

void
ftp_connect(char *host, char *user, char *pass, char *dir)
{
   int                 delay = 0;

   for (;;)
     {
	/* Wiederholungsversuche mit wachsendem Intervall, 10 min max. */
	if (delay)
	  {
	     fprintf(stderr, "ftp: connect failed, sleeping %d sec\n", delay);
	     sleep(delay);
	     delay *= 2;
	     if (delay > 600)
		delay = 600;
	  }
	else
	  {
	     delay = 5;
	  }

	/* (re-) connect */
	ftp_send(1, "close");
	ftp_recv();
	ftp_send(2, "open", host);
	if (220 != ftp_recv())
	   continue;

/*	fprintf(stderr,"ftp: connected to %s\n",host); */
	ftp_connected = 1;

	/* login */
	ftp_send(3, "user", user, pass);
	if (230 != ftp_recv())
	  {
	     if (!ftp_connected)
		continue;
	     fprintf(stderr, "ftp: login incorrect\n");
	     exit(1);
	  }

	/* set directory */
	ftp_send(2, "cd", dir);
	if (250 != ftp_recv())
	  {
	     if (!ftp_connected)
		continue;
	     fprintf(stderr, "ftp: cd %s failed\n", dir);
	     exit(1);
	  }

	/* initialisation */
	ftp_send(1, "bin");
	ftp_recv();
	ftp_send(1, "umask 022");
	ftp_recv();

	/* ok */
	break;
     }
}

void
ftp_upload(char *local, char *remote, char *tmp)
{
   ftp_send(3, "put", local, tmp);
   ftp_recv();
   ftp_send(3, "rename", tmp, remote);
   ftp_recv();
}