#include <stdio.h>
#include <termios.h>
#include <stdint.h>
#include <sys/io.h>
#include <stdlib.h>
#include <assert.h>
#include <unistd.h>
#include <poll.h>

static const int port=0x37a;
static const int port_ecr=0x37a+0x400;

#define LENGTH(x) (sizeof(x)/sizeof(*(x)))

static volatile struct termios tios;

static void cleanup(void) {
  tcsetattr(0,TCSANOW,(struct termios *)&tios);
}

int main(void) {
  uint8_t out=0x24;
  if (iopl(3)!=0) {
    fprintf(stderr,"iopl 3: %m\n");
    exit(EXIT_FAILURE);
  }
  outb(0x00,port_ecr); // Standard Mode
  int i=tcgetattr(0,(struct termios *)&tios);
  assert(i==0);
  atexit(cleanup);
  struct termios tios_raw=tios;
  cfmakeraw(&tios_raw);
  i=tcsetattr(0,TCSANOW,&tios_raw);
  assert(i==0);
  for (;;) {
    static const struct item {
      const char *name;
      uint8_t mask;
      char key;
    } items[]={
      {"DAV=pin1"  ,0x01,'1'},
      {"NRFD=pin14",0x02,'2'},
      {"NDAC=pin16",0x04,'4'},
      {"ATN=pin17" ,0x08,'8'},
      {"bidir"     ,0x20,'b'},
    };
    outb(out,port);
    usleep(1000000/10);
    uint8_t in=inb(port);
    printf("out=0x%02x in=0x%02x",out,in);
    for (const struct item *item=items;item<items+LENGTH(items);item++)
      printf(" %s:out=%d,in=%d;'%c'",item->name,!!(out&item->mask),!!(in&item->mask),item->key);
    putchar('\r');
    fflush(stdout);
    struct pollfd pollfd;
    pollfd.fd=STDIN_FILENO;
    pollfd.events=POLLIN;
    switch (poll(&pollfd,1,0)) {
      case 1: {
	char c;
	ssize_t got=read(STDIN_FILENO,&c,1);
	assert(got==1);
	if (c==27||c==3||c=='\r') {
	  putchar('\n');
	  exit(EXIT_FAILURE);
	}
	for (const struct item *item=items;item<items+LENGTH(items);item++)
	  if (c==item->key)
	    out^=item->mask;
	} break;
      case 0:
	break;
      case -1:
	abort();
    }
  }
}