#include <stdio.h>
#include <ctype.h>
#include <dos.h>
#include <bios.h>
#include <conio.h>
#include <process.h>

#define TRUE 1
#define FALSE 0
#define EOS '\O'

#define CONTROL(x) (x-0x40)
#define EXIT_KEY    CONTROL(']')
#define CTRL_B      CONTROL('B')
#define CTRL_W      CONTROL('W')
#define CTRL_E      CONTROL('E')
#define ESC_KEY	    CONTROL('[')
#define CTRL_Y      CONTROL('Y')

#define _COM_INIT 0
#define _COM_CHR8 0x03
#define _COM_STOP1 0x00
#define _COM_NOPARITY 0x00
#define _COM_1200 0x80
#define _COM_2400 0XA0
#define COM_PARAMS (_COM_CHR8 | _COM_STOP1 | _COM_NOPARITY |_COM_1200)

#define RXQSIZE 8192
#define TXQSIZE 8192

#define P8259_0    0x20
#define P8259_1    0x21
#define END_OF_INT 0x20

#define XON_ASCII  (0x11)
#define XOFF_ASCII (0x13)

#define BIOS_DATA  ((int far *)(0x400000L))

#define IER (comport + 1)
#define IIR (comport + 2)
#define LCR (comport + 3)
#define MCR (comport + 4)
#define LSR (comport + 5)
#define MSR (comport + 6)

#define RDAINT  1
#define THREINT 2
#define RLSINT  4
#define MSINT   8

#define MCRALL  15
#define MCROFF  0

#define IERALL (RDAINT+THREINT+RLSINT+MSINT)
#define IEROFF 0

#define THREOFF  0xfd

#define MDMSTATUS   0
#define TXREGEMPTY  2
#define RXDATAREADY 4
#define RLINESTATUS 6

#define XON_RCVD  1
#define XOFF_RCVD 0
#define XON_SENT  1
#define XOFF_SENT 0

#define HI_TRIGGER(x)  (3*x/4)
#define LO_TRIGGER(x)  (x/4)

#define bit0(i)  (i & 0x0001)
#define turnon_int(i,j) \
	if(((j=inp(IER))&i)==0)outp(IER,(j|i))

#define report_error(s) printf(s)

typedef struct QTYPE
{
	int count;
	int front;
	int rear;
	int maxsize;
	char *data;
} QTYPE;

static char rxbuf[RXQSIZE],
            txbuf[TXQSIZE];

static QTYPE rcvq = {0, -1, -1, RXQSIZE, rxbuf},
	     trmq = {0, -1, -1, TXQSIZE, txbuf};

int s_linestatus, s_modemstatus;

static QTYPE *txq = &trmq, *rxq = &rcvq;
static short comport=0,
             enable_xonxoff = 1,
	     rcvd_xonxoff = XON_RCVD,
	     sent_xonxoff = XON_SENT,
	     send_xon = FALSE,
	     send_xoff = FALSE,
	     int_number = 12,
	     int_enable_mask = 0xef,
	     int_disable_mask = 0x10;

int s_sendchar(int);
int s_rcvchar(void);
int s_setup(short,unsigned);
int s_cleanup(void);

char *q_getfrom( QTYPE *, char *);
int q_puton( QTYPE *, char *);

void interrupt far s_inthndlr(void);

void print_menu();
void chat();
void dial();
void hangup();
void dtr(int i);
void pr1(char *s);
void wait(long l);
void dosshell1();
void zmodemr(int port_number);
int cdet();

static void s_rda(void);
static void s_trmty(void);
static void (interrupt far *old_handler)();


main(int argc, char **argv)
{
       int ch, port_number = 0,stat;
       if (argc>1) port_number=atoi(argv[1]) -1;
       printf("\nCFHTerm : Serial I/O at 1200N81 using port COM%d\n", port_number+1);
       printf("\nConnecting...\n");
       print_menu();

       if (port_number==0)
       s_setup(port_number, (_COM_CHR8 | _COM_STOP1 | _COM_NOPARITY |_COM_1200));

       if (port_number==1)
       s_setup(port_number, (_COM_CHR8 | _COM_STOP1 | _COM_NOPARITY |_COM_2400));

       pr1("ATE0V1Q0M1X4{");
       wait(20);
       dtr(0);

      	while (TRUE)
      	{
      	  if ((ch = s_rcvchar()) != -1) putchar(ch);
      	  if (kbhit() != 0)
      	  {
	    ch=getch();
	    switch (ch) {
            case EXIT_KEY:
              s_cleanup();
       	      return;
	    case CTRL_B:
	      dial();
	      break;
	    case CTRL_W:
	      chat();
	      break;
	    case CTRL_E:
	      hangup();
	      break;
	    case ESC_KEY:
	      dosshell1();
	      break;
	    case CTRL_Y:
	      zmodemr(port_number);
	      break;
            default:
       	      s_sendchar(ch);
	    }
	  }
	 }
}

long timer1()
/* This function returns the time, in seconds since midnight. */
{
  unsigned short h,m;
  long l;

  m=peek(0x0040,0x006c);
  h=peek(0x0040,0x006e);
  l=((long)h)*65536 + ((long)m);
  return(l);
}

void wait(long l)
{
  long l1;

  l1 = timer1()+l;

  enable();
  while (timer1()<l1);
}


void zmodemr(int port_number)
{
  int stat;
  char *port;

  itoa((port_number+1),port,10);
  stat=spawnlp(P_WAIT,"dsz.com","dsz.com","port",port,"rz",NULL);
  if (stat<0)
    printf("\n\nZmodem FAILED, Notify SysOp Immediately\n\n");
  else
  {
    printf("\n\nZmodem terminated....\n\n");
    wait(5);
  }
}


void dosshell1()
{
  int stat;

  printf("\n\n\x1B[1;33mShelling to Dos...");
  printf("\nType \x1B[1;31mEXIT \x1B[1;33mto return to CFHOutlink\n\n\x1B[1;32m");
  stat=spawnlp(P_WAIT,"c:\command.com","",NULL);
  if (stat<0)
    printf("\n\nDos Shell FAILED, Notify SysOp Immediately\n\n");
  else
  {
    printf("\n\nReturning to CFHOutlink....\n\n");
    wait(5);
  }
  print_menu();
}

void dial()
{
  int i,i1;
  char s[20],s2[22]="ATDT",ch;

  printf("\nEnter the number you would like to dial: ");
  for (i=0;i<20;i++)
  {
    s[i]=getch();
    putchar(s[i]);
    if (s[i]=='\r')
    {
      s[i]='{';
      i=21;
    }
  }
  printf("\n\n");
  if (s[0]=='1')
  {
    printf("\n\nSorry NO long distance calls allowed\n\n");
    dtr(0);
    print_menu();
    return;
  }
  strcat(s2,s);
  dtr(1);
  pr1(s2);
  while (ch == -1)
  {
    if ((ch = s_rcvchar()) != -1)
      putchar(ch);
  }
  for (i=0;ch != -1;i++)
  {
    wait(1);
    if ((ch = s_rcvchar()) != -1)
     putchar(ch);
  }
  while (!(cdet()))
  {
    if ((ch = s_rcvchar()) != -1)
    {
      putchar(ch);
      if (!(cdet()))
      {
	printf("\n\nNo Carrier Detected\n\n");
	dtr(0);
	print_menu();
	return;
      }
    }
  }
}

void hangup()
{
  dtr(0);
  print_menu();
}

void chat()
{
  char ch;
  printf("\nEntering Chat with The Depths of Hell SysOp\n\n");
  while (TRUE)
  {
    if (kbhit() != 0)
    {
      ch=getch();
      switch (ch) {
      case '\r':
	printf("\n\r");
	break;
      case CTRL_W:
	printf("\n\nExiting Chat....\n\n");
	print_menu();
	return;
      default:
	putchar(ch);
      }
    }
  }
}

void print_menu()
{
  printf("\n\n\nCommands:\n");
  printf("^] to return to bbs\n");
  printf("^B to Dial a number....wait for modem response\n");
  printf("^W to chat with Depths of Hell SysOp\n");
  printf("^E to hangup\n");
  printf("ESC to Shell to DOS\n");
  printf("\n\n");
}

int cdet()
/* This returns the status of the carrier detect lead from the modem */
{
  return((inport(MSR) & 0x80) ? 1 : 0);
}

void dtr(int i)
/* This function sets the DTR pin to the status given */
{
  int i1;

  i1 = inportb(MCR) & 0x00FE;
  outportb(MCR, i ? (i1 + 1) : i1);
}

void pr1(char *s)
/* This function ouputs a string to the com port.  This is mainly used
 * for modem commands
 */
{
  int i;

  for (i = 0; s[i] > 0; i++)
    if (s[i] == '{')
    {
      s_sendchar(13);
      return;
    }
    else
      s_sendchar(s[i]);
}

void interrupt far s_inthndlr(void)
{
	register int int_id, intmask;

	enable();

	while (TRUE)
	{
	  int_id = inp(IIR);
	  if (bit0(int_id) == 1)
	  {
	  outp(P8259_0, END_OF_INT);
	  return;
          }
	  if (int_id >=RXDATAREADY)
	    turnon_int(THREINT, intmask);
	  switch (int_id)
	  {
	    case MDMSTATUS:
	      s_modemstatus = inp(MSR);
	      break;
	    case TXREGEMPTY:
	      s_trmty();
	      break;
	    case RXDATAREADY:
	      s_rda();
	      break;
	    case RLINESTATUS:
	      s_linestatus = inp(LSR);
	      break;
	  }
        }
}

static void s_rda(void)
{
	register int intmask;
	char c;

	c=inp(comport);
	if(enable_xonxoff){
	  if(c == XON_ASCII){
	    rcvd_xonxoff=XON_RCVD;
	    turnon_int(THREINT, intmask);
	    return;
	  }
	  if (c==XOFF_ASCII){
	    rcvd_xonxoff = XOFF_RCVD;
	    intmask=inp(IER);
	    if (intmask & THREINT)
	      outp(IER, intmask & THREOFF);
	    return;
          }
        }
      q_puton(rxq, &c);
      if(enable_xonxoff){
	if(rxq->count >=HI_TRIGGER(RXQSIZE) && sent_xonxoff != XOFF_SENT) {
	  send_xoff=TRUE;
	  turnon_int(THREINT,intmask);
	}
      }
}

static void s_trmty(void)
{
  char c;
  register int ierval;

  if (send_xoff == TRUE){
    outp(comport, XOFF_ASCII);
    send_xoff = FALSE;
    sent_xonxoff = XOFF_SENT;
    return;
  }
  if (send_xon==TRUE){
    outp(comport, XON_ASCII);
    send_xon = FALSE;
    sent_xonxoff=XON_SENT;
    return;
  }
  if(q_getfrom(txq, &c) != NULL){
    outp(comport,c);
    return;
  }
  ierval = inp(IER);
  if (ierval & THREINT) outp(IER, ierval &THREOFF);
}

int s_setup(short port_number, unsigned commparams)
{
  int intmask;

  if (port_number <0 || port_number >1)
    report_error("\nInvalid port number!\n");

  if (port_number==0)
  comport = 0x03f8;

  if (port_number==1)
  comport = 0x02f8;

  if (comport == 0)
  {
    report_error("\nBIOS could not find port!\n");
    return(0);
  }

  if(port_number==0)
  {
    int_enable_mask=0xef;
    int_disable_mask=0x10;
    int_number = 12;
  }

  if(port_number==1)
  {
    int_enable_mask=0xf7;
    int_disable_mask=8;
    int_number=11;
  }

  old_handler=getvect(int_number);
  disable();
  setvect(int_number, s_inthndlr);
   enable();
  bioscom(_COM_INIT, commparams, port_number);
  rcvd_xonxoff = XON_RCVD;
  if(sent_xonxoff == XOFF_SENT)
    send_xon=TRUE;
  else
    send_xon=FALSE;
  send_xoff=FALSE;
  disable();
  outp(MCR, MCRALL);
  outp(IER,IERALL);
  intmask=inp(P8259_1) & int_enable_mask;
  outp(P8259_1,intmask);
  enable();
  return(1);
}

int s_cleanup(void)
{
  int intmask;
  disable();
  outp(MCR,IEROFF);
  outp(MCR,MCROFF);
  intmask=inp(P8259_1) | int_disable_mask;
  outp(P8259_1, intmask);
  setvect(int_number, old_handler);
  enable();
  return;
}

int s_sendchar(int ch)
{
  int retval, intmask;

  disable();
  retval= q_puton(txq, (char *)&ch);
  enable();
  if (rcvd_xonxoff != XOFF_RCVD)
    turnon_int(THREINT, intmask);
  return(retval);
}

s_rcvchar(void)
{
  int ch, intmask;
  if(enable_xonxoff)
  {
    if(rxq->count <=LO_TRIGGER(RXQSIZE) && sent_xonxoff !=XON_SENT)
    {
      send_xon=TRUE;
      turnon_int(THREINT,intmask);
    }
  }
  disable();
  if(q_getfrom(rxq, (char *)&ch) == NULL)
  {
    enable();
    return(-1);
  }
  else
  {
    enable();
    return(ch);
  }
}

char *q_getfrom(QTYPE *queue, char *data)
{
  char *current;
  current=NULL;
  if(queue->front == -1) return(current);
  current = &(queue->data[queue->front]);
  *data=*current;
  queue->count--;
  if (queue->count == 0)
  {
    queue->front = queue->rear = -1;
    return(current);
  }
  if(queue->front == queue->maxsize-1)
    queue->front=0;
  else
    queue->front++;
  return(current);
}

int q_puton(QTYPE *queue, char *data)
{
  if(queue->count == queue->maxsize) return(0);
  if(queue->rear == queue->maxsize-1)
    queue->rear=0;
  else
    queue->rear++;
  queue->data[queue->rear]=*data;
  queue->count++;
  if(queue->front == -1) queue->front=0;
  return(1);
}