/* 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(void) {
	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':
			winsize++;
			if(winsize == 3) winsize = 0;
			free_pixmaps();
			XCloseDisplay(display);
			setup_x();
			load_pixmaps();
			show_value();
			break;
	}
}

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);
}