/* Copyright 1998 DJ Delorie <dj@delorie.com>
   Distributed under the terms of the GNU GPL
   http://www.delorie.com/store/hcalc/
   Revisions copyright 2007,  
   Theodore Kilgore <kilgota@auburn.edu>
	More revisions copyright 2023, B. Watson <urchlay@slackware.uk>
*/
#include "hcalc.h"
#include <ctype.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
#include <math.h>

char pending_op = 0;
int making_number = 0;
int base = 10;
int quiet = 0;
int showing_err = 0;

#define MAXIN 40

char input_buf[MAXIN];
int iptr;
double value, saved, stored=0;

void paste(void);
void copy(void);

int number_is_ok(double n) {
	return (fpclassify(n) & (FP_ZERO | FP_NORMAL ));
}

void bell(void) {
	if(!quiet)
		XBell(display, 0);
}

void
convert_number()
{
  char *ip = input_buf;
  double scale = 1;
  int sign = +1;

  if (*ip == '-')
    sign = -1;
  value = 0;
  while (*++ip)
  {
    if (*ip == '.')
      break;
    if (*ip >= '0' && *ip <= '9')
    {
      value *= base;
      value += *ip-'0';
    }
    if (*ip >= 'a' && *ip <= 'f')
    {
      value *= base;
      value += *ip-'a'+10;
    }
  }
  if (*ip)
    while (*++ip)
    {
      if (*ip >= '0' && *ip <= '9')
      {
	scale *= base;
	value += (*ip-'0')/scale;
      }
      if (*ip >= 'a' && *ip <= 'f')
      {
	scale *= base;
	value += (*ip-'a'+10)/scale;
      }
    }
  value *= sign;
}

void
show_value()
{
  char tmp[25], *tp;
  char commas[40], *cp, *dp;
  double v = value;

  if(!number_is_ok(value)) {
    set_string("Err");
    bell();
    showing_err = 1;
	 saved = value = 0; /* so it doesn't get saved on exit! */
    return;
  }

  if (base == 2)
  {
    int q = (long long)v & 0xffffffffL;
    set_bits(q);
    return;
  }

  tmp[0] = ' ';
  if (v < 0)
  {
    tmp[0] = '-';
    v = -v;
  }

  if (base == 10)
  {
    sprintf(tmp+1, "%.14G", v);
    if (strchr(tmp+1, 'E'))
      sprintf(tmp+1, "%.9G", v);
    if (tmp[14] == '.')
      tmp[14] = 0;
  }
  else
  {
    static char tohex[] = "0123456789ABCDEF";
    long long ll = (long long)v;
    char *revptr;
    tp = tmp+1;
    if (base == 16)
    {
      *tp++ = '0';
      *tp++ = 'x';
    }
    else if (base == 8)
      *tp++ = '0';

    revptr = tp;
    do {
      *tp++ = tohex[ll%base];
      ll /= base;
    } while (ll);
    *tp-- = 0;
    while (revptr < tp) {
      char t = *revptr;
      *revptr = *tp;
      *tp = t;
      tp--;
      revptr++;
    }
  }

  cp = commas+40;
  tp = tmp+strlen(tmp);
  dp = strchr(tmp, '.');
  if (dp == 0)
    dp = tp;

  *--cp = 0;
  while (tp>=tmp)
  {
    *--cp = *tp--;
    switch (base)
    {
    case 10:
      if (isdigit(cp[0]) && isdigit(cp[1]) && isdigit(cp[2]) && tp<dp
	  && tp>=tmp && isdigit(*tp))
	*--cp = ',';
      break;
    case 16:
      if (isxdigit(cp[0]) && isxdigit(cp[1])
	  && isxdigit(cp[2]) && isxdigit(cp[3])
	  && tp>=tmp && isxdigit(*tp))
	*--cp = ',';
      break;
    }
  }

  if (strlen(cp) > 15)
    set_string(tmp);
  else
    set_string(cp);
}

void
end_number()
{
  if (!making_number)
    return;
  making_number = 0;
  iptr = 0;

  switch (pending_op)
  {
  case '+':
    value = saved + value;
    break;
  case '-':
    value = saved - value;
    break;
  case '*':
    value = saved * value;
    break;
  case '/':
    value = saved / value;
    break;
  case '%':
    value = (long long)saved % (long long)value;
    break;
  case '&':
    value = (long long)saved & (long long)value;
    break;
  case '|':
    value = (long long)saved | (long long)value;
    break;
  case '^':
    value = (long long)saved ^ (long long)value;
    break;
  case 'S':	/* Shift. Positive means <<, negative means >> */
    if (value < 0)
      value = (long long)saved >> (long long)(-value);
    else
      value = (long long)saved << (long long)value;
    break;
  }
  saved = value;
  pending_op = 0;
  show_value();
}

void
start_number()
{
  if (making_number)
    return;

  iptr = 1;
  input_buf[0] = ' ';
  input_buf[1] = 0;
  making_number = 1;
}

void
key(char c)
{
  int v = c;
  /* printf("key_number 0x%x\n", v); */

  if(showing_err) {
    switch(c) {
      /* list the keys that should be still active in error state */
      case 27:
      case 'C':
      case 'Q':
      case 17:
        break;
      default:
        bell();
        return;
	 }
  }

  switch (c)
  {
  case 27:
  case 'C':
    showing_err = 0;
    making_number = 0;
    iptr = 0;
    pending_op = 0;
    value = saved = 0;
    set_string("");
	 show_value();
    break;
  case 'u':
    if (making_number)
    {
      making_number = 0;
      set_string("");
    }
    break;

  case 'a':
  case 'b':
  case 'c':
  case 'd':
  case 'e':
  case 'f':
    v = c - 39;
  case '0':
  case '1':
  case '2':
  case '3':
  case '4':
  case '5':
  case '6':
  case '7':
  case '8':
  case '9':
    v -= '0';
    if (v >= base || iptr == MAXIN-1)
      bell();
    else
    {
      start_number();
      input_buf[iptr++] = c;
      input_buf[iptr] = 0;
      convert_number();
      show_value();
    }
    break;
  case '.':
    if (strchr(input_buf, '.'))
    {
      bell();
      break;
    }
  case ',':
    if (iptr == 1 || iptr == MAXIN-1)
      bell();
    else
    {
      start_number();
      input_buf[iptr++] = c;
      input_buf[iptr] = 0;
      convert_number();
      show_value();
    }
    break;

  case 8:
  case 127:
    if (iptr <= 1)
      bell();
    else
    {
      input_buf[--iptr] = 0;
      convert_number();
      show_value();
    }
    break;

  case '_': /* The +/- key */
  case 'i':
    if (making_number)
    {
      if (input_buf[0] == '-')
	input_buf[0] = ' ';
      else
	input_buf[0] = '-';
      convert_number();
      show_value();
    }
    else
    {
      value *= -1.0;
      saved *= -1.0;
      show_value();
    }
    break;

  case 'D':
    end_number();
    base = 10;
    show_value();
    break;
  case 'H':
    end_number();
    base = 16;
    show_value();
    break;
  case 'O':
    end_number();
    base = 8;
    show_value();
    break;
  case 'B':
    end_number();
    base = 2;
    show_value();
    break;

  case 'x':	/* Allow 'x' on keyboard to be used to enter '*' */
    c = '*';
  case '+':
  case '-':
  case '*':
  case '/':
  case '%':
  case '^':
  case '&':
  case '|':
  case 'S':
  case '=':
    end_number();
    pending_op = c;
    break;

  case 13:
  case 10:
    end_number();
    pending_op = '=';
    break;

  case '~':	/* Invert bits (one's complement) */
    end_number();
    value = ~ (long long)value;
    saved = value;
    show_value();
    break;

  case '@':	/* Two's complement */
    end_number();
    {
      unsigned int i = ((unsigned int)value) & 0xffffffff;
      value = ~i + 1;
    }
    saved = value;
    show_value();
    break;

  case '<': /* SHL by one bit only */
/* Modified by Keith Meehl to fix bit shift bug*/
    end_number();
    value = (long long)value << 1;
    saved = value;
    pending_op = 0;
    show_value();
    break;

  case '>': /* SHR by one bit only */
/* Modified by Keith Meehl to fix bit shift bug*/
    end_number();
    value = (long long)value >> 1;
    saved = value;
    pending_op = 0;
    show_value();
    break;

  case '[': /* STO */
    stored = value;
    break;
  case ']': /* RCL */
    value = stored;
    show_value();
    making_number = 1;
    iptr = 1;
    input_buf[0] = ' ';
    break;
  case '}': /* SUM */
    stored += value;
    break;

  case 'P': /* click on the display itself */
    break;

  case 3:   /* ^C */
	 copy();
	 break;

  case 22:  /* ^V */
	 paste();
	 break;

  case 'q':
    quiet = !quiet;
	 break;

  case 'Q':
  case 17:
    exit(0);

  case 'z':
	 {
       /* dirty hack method of changing window size:
          re-execute ourselves with appropriate argument.
          TODO: see if this leaks memory, fds, etc */
      extern char *self;
      char *args[4];

		args[0] = self;

		switch(winsize) {
			case 0:
				args[1] = "-medium";
				break;
			case 1:
				args[1] = "-large";
				break;
			case 2:
				args[1] = "-small";
				break;
		}

		args[2] = NULL;

      /* note that atexit() functions do NOT get called on execv() */
		save_config();

		XCloseDisplay(display);

      execv(self, args);
	 }
  }
}

static char *bmap[] = {
  "PPPP\033", 	/* mouse copy and paste, CLR	*/
  "DHOB\010", 	/* DEC, HEX, OCT, BIN, DEL	*/
  "[]}<>",    	/* STO, RCL, SUM, <<, >>	*/
  "Sdef/",    	/* SHF, D    E    F   /		*/
  "~abc*",	/* INV, 			*/
  "|789-",	/* OR, 				*/
  "&456+",	/* AND, 			*/
  "^123=",	/* XOR, 			*/
  "u0._="	/* CE, 0,  . , +/-, =		*/
};

void
copy(void)
{
  XSetSelectionOwner(display, XA_PRIMARY, window, event.xbutton.time);
}

void
paste(void)
{
  XConvertSelection(display, XA_PRIMARY, XA_STRING, paste_atom, window,
		    event.xbutton.time);
}

void
complete_paste(unsigned char *s, int n)
{
  int i;
  for (i=0; i<n; i++)
    key(s[i]);
  
}

void
button(int b, int x, int y)
{
  char k;

  if(b == 2) {
	  paste();
	  return;
  }

  x = (x-2)/(24 * scale_factor);
  if (x < 0) x = 0;
  if (x > 4) x = 4;
  y = (y-1)/(16 * scale_factor);
  if (y < 0) y = 0;
  if (y > 8) y = 8;

  k = bmap[y][x];

  if (k == 27 && b == 3)
    exit(0);

  if (k == 'P' && b == 1)
    copy();
  else if (k == 'P' && b != 1)
    paste();
  else if(k == '/' && b != 1)
    key('%');
  else if(k == '~' && b != 1)
    key('@');
  else
    key(k);
}