//*****************************************************************************
//   Kontrollprogramm für die I2C HoterModem 
//
//   g++ -o {prog} {prog.c} && ./prog /dev/ttyUSB0
//*****************************************************************************

#include <stdio.h>
#include <stdlib.h>
#include <sys/ioctl.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <signal.h>
#include <termios.h>
#include <string.h>
#include <stdbool.h>

int fd = 0;

int main(int argc, char** argv)
{
  struct termios oldtios,options;
  int currstat = 0;
  if((argc < 2)||(argc > 3))
    {
      printf("Fehler: Ungültige Parameter-Anzahl.\n");
      printf("Aufruf:\n");
      printf("  %s <device>\n",argv[0]);
      return 1;
    }

  /* Das Device öffnen */
  if((fd = open(argv[1], O_RDWR | O_NOCTTY | O_NDELAY)) < 0)
    {
      printf("Fehler: Device \"%s\" kann nicht geöffnet werden.\n", argv[1]);
      return 2;
    }

  tcgetattr(fd,&oldtios);
  options.c_cflag = 0;
  options.c_lflag = 0;
  options.c_iflag = 0;
  //options.c_cc    = 0;

  fcntl(fd, F_SETFL, 0);
  if (tcgetattr(fd, &options) != 0) return(-1);
  printf ("\nVOR tcsetattr\n");
  char cmd[20];


  sprintf(cmd,"stty -a < %s",argv[1]);
  system(cmd);
  printf ("\n\n");

  cfsetispeed(&options, B115200);            /* setze 115200 bps */
  cfsetospeed(&options, B115200);

  options.c_cflag &= ~PARENB;               /*  kein Paritybit */
  options.c_cflag &= ~CSTOPB;               /* 1 Stopbit */
  options.c_cflag &= ~CSIZE;                /* 8 Datenbits */
  options.c_cflag |= CS8; 
  options.c_cflag &= ~CRTSCTS;
  options.c_cflag |= (CLOCAL | CREAD);      /* CD-Signal ignorieren */
  /* Kein Echo, keine Steuerzeichen, keine Interrupts */
  options.c_lflag &= ~(ICANON | ECHO | ECHOE | ISIG | ECHOCTL);
  //options.c_oflag &= ~OPOST;                /* setze "raw" Input */
  options.c_oflag = OPOST | ONLCR;
  options.c_oflag &= ~IGNPAR;
  options.c_iflag &= ~(IXON | IXOFF | IXANY | IGNPAR);
  //options.c_iflag &= ~IGNPAR;
  //options.c_lflag &= ~IGNPAR;
  options.c_iflag = IGNPAR | ICRNL;
  options.c_cc[VMIN]  = 0;                  /* warten auf min. 0 Zeichen */
  options.c_cc[VTIME] = 10;                 /* Timeout 10 Sekunden */

  tcflush(fd,TCIOFLUSH);
  if (tcsetattr(fd, TCSAFLUSH, &options) != 0) return(-1);
  char buffer[8];
  
  printf ("\nNach tcsetattr\n");
  sprintf(cmd,"stty -a < %s",argv[1]);
  system(cmd);
  printf ("\n\n");
  // Version
  buffer[0]=0x0C;
  buffer[1]=0x00;
  buffer[2]=0x04;


  printf("-Eingabe---------------------\n");
  int i;
  for (i=0; i<3; i++ )
  {
    printf("0x%02x ",buffer[i]);
  }
  printf("\n");
  printf("-----------------------------\n");

  // buffer schreiben
  i = write(fd,buffer,3); //ist das OK?
  printf("geschrieben: %i\n",i);
  printf("-----------------------------\n");

  int bb = 0;
  int x = 0;
  bool cmdOK=false;
  char cods[10];

  /*

      ABHIER?
      Lese des Gerätes, antwort solte sein:
      0x1A, 0x03, 0x02, 0x00, 0x00, 0x04 (0x04 sollte EOT sein)
      aber was ist da falsch?
  */
  do
  {
    //printf("\n");
    if((bb = read( fd, &cods[x], sizeof( cods )-x )) > 0)
    //if((bb = read( fd, &cods, 5 )) > 0)
    {
      for (i=x;i<x+bb;i++)
        {
          printf("0x%02x ",cods[i]);
          if (cods[i]==0x04) cmdOK=true;
        }
      x+=bb;
      //printf("\n");
      printf("in if: x=%d\n",x);
    }
    //printf("nach if bb=%d\n",bb);

  }while(!cmdOK);

  printf("-Ausgabe---------------------\n");
  for (i=0; i<x; i++ )
  {
    printf("0x%02x ",cods[i]);
  }
  printf("\n");
  printf("-----------------------------\n");


  close(fd);


  // TTYS0 auf alten Wert setzen
  tcflush(fd,TCIOFLUSH);
  if (tcsetattr(fd, TCSAFLUSH, &oldtios) != 0) return(-1);

  return 0;
}