/*-*- mode:c;indent-tabs-mode:t;c-basic-offset:8;tab-width:8;coding:utf-8   -*-│
│ vi: set noet ft=c ts=8 sw=8 fenc=utf-8                                   :vi │
╚──────────────────────────────────────────────────────────────────────────────╝
│                                                                              │
│ Copyright (C) Lucent Technologies 1997                                       │
│ All Rights Reserved                                                          │
│                                                                              │
│ Permission to use, copy, modify, and distribute this software and            │
│ its documentation for any purpose and without fee is hereby                  │
│ granted, provided that the above copyright notice appear in all              │
│ copies and that both that the copyright notice and this                      │
│ permission notice and warranty disclaimer appear in supporting               │
│ documentation, and that the name Lucent Technologies or any of               │
│ its entities not be used in advertising or publicity pertaining              │
│ to distribution of the software without specific, written prior              │
│ permission.                                                                  │
│                                                                              │
│ LUCENT DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,                │
│ INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS.             │
│ IN NO EVENT SHALL LUCENT OR ANY OF ITS ENTITIES BE LIABLE FOR ANY            │
│ SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES                    │
│ WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER              │
│ IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION,               │
│ ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF               │
│ THIS SOFTWARE.                                                               │
│                                                                              │
╚─────────────────────────────────────────────────────────────────────────────*/
#define DEBUG
#include "libc/fmt/conv.h"
#include "libc/math.h"
#include "libc/mem/mem.h"
#include "libc/str/str.h"
#include "third_party/awk/awk.h"

#define	FULLTAB	2	/* rehash when table gets this x full */
#define	GROWTAB 4	/* grow table by this factor */

Array	*symtab;	/* main symbol table */

char	**FS;		/* initial field sep */
char	**RS;		/* initial record sep */
char	**OFS;		/* output field sep */
char	**ORS;		/* output record sep */
char	**OFMT;		/* output format for numbers */
char	**CONVFMT;	/* format for conversions in getsval */
Awkfloat *NF;		/* number of fields in current record */
Awkfloat *NR;		/* number of current record */
Awkfloat *FNR;		/* number of current record in current file */
char	**FILENAME;	/* current filename argument */
Awkfloat *ARGC;		/* number of arguments from command line */
char	**SUBSEP;	/* subscript separator for a[i,j,k]; default \034 */
Awkfloat *RSTART;	/* start of re matched with ~; origin 1 (!) */
Awkfloat *RLENGTH;	/* length of same */

Cell	*fsloc;		/* FS */
Cell	*nrloc;		/* NR */
Cell	*nfloc;		/* NF */
Cell	*fnrloc;	/* FNR */
Cell	*ofsloc;	/* OFS */
Cell	*orsloc;	/* ORS */
Cell	*rsloc;		/* RS */
Array	*ARGVtab;	/* symbol table containing ARGV[...] */
Array	*ENVtab;	/* symbol table containing ENVIRON[...] */
Cell	*rstartloc;	/* RSTART */
Cell	*rlengthloc;	/* RLENGTH */
Cell	*subseploc;	/* SUBSEP */
Cell	*symtabloc;	/* SYMTAB */

Cell	*nullloc;	/* a guaranteed empty cell */
Node	*nullnode;	/* zero&null, converted into a node for comparisons */
Cell	*literal0;

extern Cell **fldtab;

void syminit(void)	/* initialize symbol table with builtin vars */
{
	literal0 = setsymtab("0", "0", 0.0, NUM|STR|CON|DONTFREE, symtab);
	/* this is used for if(x)... tests: */
	nullloc = setsymtab("$zero&null", "", 0.0, NUM|STR|CON|DONTFREE, symtab);
	nullnode = celltonode(nullloc, CCON);

	fsloc = setsymtab("FS", " ", 0.0, STR|DONTFREE, symtab);
	FS = &fsloc->sval;
	rsloc = setsymtab("RS", "\n", 0.0, STR|DONTFREE, symtab);
	RS = &rsloc->sval;
	ofsloc = setsymtab("OFS", " ", 0.0, STR|DONTFREE, symtab);
	OFS = &ofsloc->sval;
	orsloc = setsymtab("ORS", "\n", 0.0, STR|DONTFREE, symtab);
	ORS = &orsloc->sval;
	OFMT = &setsymtab("OFMT", "%.6g", 0.0, STR|DONTFREE, symtab)->sval;
	CONVFMT = &setsymtab("CONVFMT", "%.6g", 0.0, STR|DONTFREE, symtab)->sval;
	FILENAME = &setsymtab("FILENAME", "", 0.0, STR|DONTFREE, symtab)->sval;
	nfloc = setsymtab("NF", "", 0.0, NUM, symtab);
	NF = &nfloc->fval;
	nrloc = setsymtab("NR", "", 0.0, NUM, symtab);
	NR = &nrloc->fval;
	fnrloc = setsymtab("FNR", "", 0.0, NUM, symtab);
	FNR = &fnrloc->fval;
	subseploc = setsymtab("SUBSEP", "\034", 0.0, STR|DONTFREE, symtab);
	SUBSEP = &subseploc->sval;
	rstartloc = setsymtab("RSTART", "", 0.0, NUM, symtab);
	RSTART = &rstartloc->fval;
	rlengthloc = setsymtab("RLENGTH", "", 0.0, NUM, symtab);
	RLENGTH = &rlengthloc->fval;
	symtabloc = setsymtab("SYMTAB", "", 0.0, ARR, symtab);
	free(symtabloc->sval);
	symtabloc->sval = (char *) symtab;
}

void arginit(int ac, char **av)	/* set up ARGV and ARGC */
{
	Cell *cp;
	int i;
	char temp[50];

	ARGC = &setsymtab("ARGC", "", (Awkfloat) ac, NUM, symtab)->fval;
	cp = setsymtab("ARGV", "", 0.0, ARR, symtab);
	ARGVtab = makesymtab(NSYMTAB);	/* could be (int) ARGC as well */
	free(cp->sval);
	cp->sval = (char *) ARGVtab;
	for (i = 0; i < ac; i++) {
		double result;

		sprintf(temp, "%d", i);
		if (is_number(*av, & result))
			setsymtab(temp, *av, result, STR|NUM, ARGVtab);
		else
			setsymtab(temp, *av, 0.0, STR, ARGVtab);
		av++;
	}
}

void envinit(char **envp)	/* set up ENVIRON variable */
{
	Cell *cp;
	char *p;

	cp = setsymtab("ENVIRON", "", 0.0, ARR, symtab);
	ENVtab = makesymtab(NSYMTAB);
	free(cp->sval);
	cp->sval = (char *) ENVtab;
	for ( ; *envp; envp++) {
		double result;

		if ((p = strchr(*envp, '=')) == NULL)
			continue;
		if( p == *envp ) /* no left hand side name in env string */
			continue;
		*p++ = 0;	/* split into two strings at = */
		if (is_number(p, & result))
			setsymtab(*envp, p, result, STR|NUM, ENVtab);
		else
			setsymtab(*envp, p, 0.0, STR, ENVtab);
		p[-1] = '=';	/* restore in case env is passed down to a shell */
	}
}

Array *makesymtab(int n)	/* make a new symbol table */
{
	Array *ap;
	Cell **tp;

	ap = (Array *) malloc(sizeof(*ap));
	tp = (Cell **) calloc(n, sizeof(*tp));
	if (ap == NULL || tp == NULL)
		FATAL("out of space in makesymtab");
	ap->nelem = 0;
	ap->size = n;
	ap->tab = tp;
	return(ap);
}

void freesymtab(Cell *ap)	/* free a symbol table */
{
	Cell *cp, *temp;
	Array *tp;
	int i;

	if (!isarr(ap))
		return;
	tp = (Array *) ap->sval;
	if (tp == NULL)
		return;
	for (i = 0; i < tp->size; i++) {
		for (cp = tp->tab[i]; cp != NULL; cp = temp) {
			xfree(cp->nval);
			if (freeable(cp))
				xfree(cp->sval);
			temp = cp->cnext;	/* avoids freeing then using */
			free(cp);
			tp->nelem--;
		}
		tp->tab[i] = NULL;
	}
	if (tp->nelem != 0)
		WARNING("can't happen: inconsistent element count freeing %s", ap->nval);
	free(tp->tab);
	free(tp);
}

void freeelem(Cell *ap, const char *s)	/* free elem s from ap (i.e., ap["s"] */
{
	Array *tp;
	Cell *p, *prev = NULL;
	int h;

	tp = (Array *) ap->sval;
	h = hash(s, tp->size);
	for (p = tp->tab[h]; p != NULL; prev = p, p = p->cnext)
		if (strcmp(s, p->nval) == 0) {
			if (prev == NULL)	/* 1st one */
				tp->tab[h] = p->cnext;
			else			/* middle somewhere */
				prev->cnext = p->cnext;
			if (freeable(p))
				xfree(p->sval);
			free(p->nval);
			free(p);
			tp->nelem--;
			return;
		}
}

Cell *setsymtab(const char *n, const char *s, Awkfloat f, unsigned t, Array *tp)
{
	int h;
	Cell *p;

	if (n != NULL && (p = lookup(n, tp)) != NULL) {
		DPRINTF("setsymtab found %p: n=%s s=\"%s\" f=%g t=%o\n",
			(void*)p, NN(p->nval), NN(p->sval), p->fval, p->tval);
		return(p);
	}
	p = (Cell *) malloc(sizeof(*p));
	if (p == NULL)
		FATAL("out of space for symbol table at %s", n);
	p->nval = tostring(n);
	p->sval = s ? tostring(s) : tostring("");
	p->fval = f;
	p->tval = t;
	p->csub = CUNK;
	p->ctype = OCELL;
	tp->nelem++;
	if (tp->nelem > FULLTAB * tp->size)
		rehash(tp);
	h = hash(n, tp->size);
	p->cnext = tp->tab[h];
	tp->tab[h] = p;
	DPRINTF("setsymtab set %p: n=%s s=\"%s\" f=%g t=%o\n",
		(void*)p, p->nval, p->sval, p->fval, p->tval);
	return(p);
}

int hash(const char *s, int n)	/* form hash value for string s */
{
	unsigned hashval;

	for (hashval = 0; *s != '\0'; s++)
		hashval = (*s + 31 * hashval);
	return hashval % n;
}

void rehash(Array *tp)	/* rehash items in small table into big one */
{
	int i, nh, nsz;
	Cell *cp, *op, **np;

	nsz = GROWTAB * tp->size;
	np = (Cell **) calloc(nsz, sizeof(*np));
	if (np == NULL)		/* can't do it, but can keep running. */
		return;		/* someone else will run out later. */
	for (i = 0; i < tp->size; i++) {
		for (cp = tp->tab[i]; cp; cp = op) {
			op = cp->cnext;
			nh = hash(cp->nval, nsz);
			cp->cnext = np[nh];
			np[nh] = cp;
		}
	}
	free(tp->tab);
	tp->tab = np;
	tp->size = nsz;
}

Cell *lookup(const char *s, Array *tp)	/* look for s in tp */
{
	Cell *p;
	int h;

	h = hash(s, tp->size);
	for (p = tp->tab[h]; p != NULL; p = p->cnext)
		if (strcmp(s, p->nval) == 0)
			return(p);	/* found it */
	return(NULL);			/* not found */
}

Awkfloat setfval(Cell *vp, Awkfloat f)	/* set float val of a Cell */
{
	int fldno;

	f += 0.0;		/* normalise negative zero to positive zero */
	if ((vp->tval & (NUM | STR)) == 0)
		funnyvar(vp, "assign to");
	if (isfld(vp)) {
		donerec = false;	/* mark $0 invalid */
		fldno = atoi(vp->nval);
		if (fldno > *NF)
			newfld(fldno);
		DPRINTF("setting field %d to %g\n", fldno, f);
	} else if (&vp->fval == NF) {
		donerec = false;	/* mark $0 invalid */
		setlastfld(f);
		DPRINTF("setting NF to %g\n", f);
	} else if (isrec(vp)) {
		donefld = false;	/* mark $1... invalid */
		donerec = true;
		savefs();
	} else if (vp == ofsloc) {
		if (!donerec)
			recbld();
	}
	if (freeable(vp))
		xfree(vp->sval); /* free any previous string */
	vp->tval &= ~(STR|CONVC|CONVO); /* mark string invalid */
	vp->fmt = NULL;
	vp->tval |= NUM;	/* mark number ok */
	if (f == -0)  /* who would have thought this possible? */
		f = 0;
	DPRINTF("setfval %p: %s = %g, t=%o\n", (void*)vp, NN(vp->nval), f, vp->tval);
	return vp->fval = f;
}

void funnyvar(Cell *vp, const char *rw)
{
	if (isarr(vp))
		FATAL("can't %s %s; it's an array name.", rw, vp->nval);
	if (vp->tval & FCN)
		FATAL("can't %s %s; it's a function.", rw, vp->nval);
	WARNING("funny variable %p: n=%s s=\"%s\" f=%g t=%o",
		(void *)vp, vp->nval, vp->sval, vp->fval, vp->tval);
}

char *setsval(Cell *vp, const char *s)	/* set string val of a Cell */
{
	char *t;
	int fldno;
	Awkfloat f;

	DPRINTF("starting setsval %p: %s = \"%s\", t=%o, r,f=%d,%d\n",
		(void*)vp, NN(vp->nval), s, vp->tval, donerec, donefld);
	if ((vp->tval & (NUM | STR)) == 0)
		funnyvar(vp, "assign to");
	if (isfld(vp)) {
		donerec = false;	/* mark $0 invalid */
		fldno = atoi(vp->nval);
		if (fldno > *NF)
			newfld(fldno);
		DPRINTF("setting field %d to %s (%p)\n", fldno, s, (const void*)s);
	} else if (isrec(vp)) {
		donefld = false;	/* mark $1... invalid */
		donerec = true;
		savefs();
	} else if (vp == ofsloc) {
		if (!donerec)
			recbld();
	}
	t = s ? tostring(s) : tostring("");	/* in case it's self-assign */
	if (freeable(vp))
		xfree(vp->sval);
	vp->tval &= ~(NUM|DONTFREE|CONVC|CONVO);
	vp->tval |= STR;
	vp->fmt = NULL;
	DPRINTF("setsval %p: %s = \"%s (%p) \", t=%o r,f=%d,%d\n",
		(void*)vp, NN(vp->nval), t, (void*)t, vp->tval, donerec, donefld);
	vp->sval = t;
	if (&vp->fval == NF) {
		donerec = false;	/* mark $0 invalid */
		f = getfval(vp);
		setlastfld(f);
		DPRINTF("setting NF to %g\n", f);
	}

	return(vp->sval);
}

Awkfloat getfval(Cell *vp)	/* get float val of a Cell */
{
	if ((vp->tval & (NUM | STR)) == 0)
		funnyvar(vp, "read value of");
	if (isfld(vp) && !donefld)
		fldbld();
	else if (isrec(vp) && !donerec)
		recbld();
	if (!isnum(vp)) {	/* not a number */
		double fval;
		bool no_trailing;

		if (is_valid_number(vp->sval, true, & no_trailing, & fval)) {
			vp->fval = fval;
			if (no_trailing && !(vp->tval&CON))
				vp->tval |= NUM;	/* make NUM only sparingly */
		} else
			vp->fval = 0.0;
	}
	DPRINTF("getfval %p: %s = %g, t=%o\n",
		(void*)vp, NN(vp->nval), vp->fval, vp->tval);
	return(vp->fval);
}

static const char *get_inf_nan(double d)
{
	if (isinf(d)) {
		return (d < 0 ? "-inf" : "+inf");
	} else if (isnan(d)) {
		return (signbit(d) != 0 ? "-nan" : "+nan");
	} else
		return NULL;
}

static char *get_str_val(Cell *vp, char **fmt)        /* get string val of a Cell */
{
	char s[256];
	double dtemp;
	const char *p;

	if ((vp->tval & (NUM | STR)) == 0)
		funnyvar(vp, "read value of");
	if (isfld(vp) && ! donefld)
		fldbld();
	else if (isrec(vp) && ! donerec)
		recbld();

	/*
	 * ADR: This is complicated and more fragile than is desirable.
	 * Retrieving a string value for a number associates the string
	 * value with the scalar.  Previously, the string value was
	 * sticky, meaning if converted via OFMT that became the value
	 * (even though POSIX wants it to be via CONVFMT). Or if CONVFMT
	 * changed after a string value was retrieved, the original value
	 * was maintained and used.  Also not per POSIX.
	 *
	 * We work around this design by adding two additional flags,
	 * CONVC and CONVO, indicating how the string value was
	 * obtained (via CONVFMT or OFMT) and _also_ maintaining a copy
	 * of the pointer to the xFMT format string used for the
	 * conversion.  This pointer is only read, **never** dereferenced.
	 * The next time we do a conversion, if it's coming from the same
	 * xFMT as last time, and the pointer value is different, we
	 * know that the xFMT format string changed, and we need to
	 * redo the conversion. If it's the same, we don't have to.
	 *
	 * There are also several cases where we don't do a conversion,
	 * such as for a field (see the checks below).
	 */

	/* Don't duplicate the code for actually updating the value */
#define update_str_val(vp) \
	{ \
		if (freeable(vp)) \
			xfree(vp->sval); \
		if ((p = get_inf_nan(vp->fval)) != NULL) \
			strcpy(s, p); \
		else if (modf(vp->fval, &dtemp) == 0)	/* it's integral */ \
			snprintf(s, sizeof (s), "%.30g", vp->fval); \
		else \
			snprintf(s, sizeof (s), *fmt, vp->fval); \
		vp->sval = tostring(s); \
		vp->tval &= ~DONTFREE; \
		vp->tval |= STR; \
	}

	if (isstr(vp) == 0) {
		update_str_val(vp);
		if (fmt == OFMT) {
			vp->tval &= ~CONVC;
			vp->tval |= CONVO;
		} else {
			/* CONVFMT */
			vp->tval &= ~CONVO;
			vp->tval |= CONVC;
		}
		vp->fmt = *fmt;
	} else if ((vp->tval & DONTFREE) != 0 || ! isnum(vp) || isfld(vp)) {
		goto done;
	} else if (isstr(vp)) {
		if (fmt == OFMT) {
			if ((vp->tval & CONVC) != 0
			    || ((vp->tval & CONVO) != 0 && vp->fmt != *fmt)) {
				update_str_val(vp);
				vp->tval &= ~CONVC;
				vp->tval |= CONVO;
				vp->fmt = *fmt;
			}
		} else {
			/* CONVFMT */
			if ((vp->tval & CONVO) != 0
			    || ((vp->tval & CONVC) != 0 && vp->fmt != *fmt)) {
				update_str_val(vp);
				vp->tval &= ~CONVO;
				vp->tval |= CONVC;
				vp->fmt = *fmt;
			}
		}
	}
done:
	DPRINTF("getsval %p: %s = \"%s (%p)\", t=%o\n",
		(void*)vp, NN(vp->nval), vp->sval, (void*)vp->sval, vp->tval);
	return(vp->sval);
}

char *getsval(Cell *vp)       /* get string val of a Cell */
{
      return get_str_val(vp, CONVFMT);
}

char *getpssval(Cell *vp)     /* get string val of a Cell for print */
{
      return get_str_val(vp, OFMT);
}


char *tostring(const char *s)	/* make a copy of string s */
{
	char *p = strdup(s);
	if (p == NULL)
		FATAL("out of space in tostring on %s", s);
	return(p);
}

char *tostringN(const char *s, size_t n)	/* make a copy of string s */
{
	char *p;

	p = (char *) malloc(n);
	if (p == NULL)
		FATAL("out of space in tostring on %s", s);
	strcpy(p, s);
	return(p);
}

Cell *catstr(Cell *a, Cell *b) /* concatenate a and b */
{
	Cell *c;
	char *p;
	char *sa = getsval(a);
	char *sb = getsval(b);
	size_t l = strlen(sa) + strlen(sb) + 1;
	p = (char *) malloc(l);
	if (p == NULL)
		FATAL("out of space concatenating %s and %s", sa, sb);
	snprintf(p, l, "%s%s", sa, sb);

	l++;	// add room for ' '
	char *newbuf = (char *) malloc(l);
	if (newbuf == NULL)
		FATAL("out of space concatenating %s and %s", sa, sb);
	// See string() in lex.c; a string "xx" is stored in the symbol
	// table as "xx ".
	snprintf(newbuf, l, "%s ", p);
	c = setsymtab(newbuf, p, 0.0, CON|STR|DONTFREE, symtab);
	free(p);
	free(newbuf);
	return c;
}

char *qstring(const char *is, int delim)	/* collect string up to next delim */
{
	const char *os = is;
	int c, n;
	const uschar *s = (const uschar *) is;
	uschar *buf, *bp;

	if ((buf = (uschar *) malloc(strlen(is)+3)) == NULL)
		FATAL( "out of space in qstring(%s)", s);
	for (bp = buf; (c = *s) != delim; s++) {
		if (c == '\n')
			SYNTAX( "newline in string %.20s...", os );
		else if (c != '\\')
			*bp++ = c;
		else {	/* \something */
			c = *++s;
			if (c == 0) {	/* \ at end */
				*bp++ = '\\';
				break;	/* for loop */
			}
			switch (c) {
			case '\\':	*bp++ = '\\'; break;
			case 'n':	*bp++ = '\n'; break;
			case 't':	*bp++ = '\t'; break;
			case 'b':	*bp++ = '\b'; break;
			case 'f':	*bp++ = '\f'; break;
			case 'r':	*bp++ = '\r'; break;
			case 'v':	*bp++ = '\v'; break;
			case 'a':	*bp++ = '\a'; break;
			default:
				if (!isdigit(c)) {
					*bp++ = c;
					break;
				}
				n = c - '0';
				if (isdigit(s[1])) {
					n = 8 * n + *++s - '0';
					if (isdigit(s[1]))
						n = 8 * n + *++s - '0';
				}
				*bp++ = n;
				break;
			}
		}
	}
	*bp++ = 0;
	return (char *) buf;
}

const char *flags2str(int flags)
{
	static const struct ftab {
		const char *name;
		int value;
	} flagtab[] = {
		{ "NUM", NUM },
		{ "STR", STR },
		{ "DONTFREE", DONTFREE },
		{ "CON", CON },
		{ "ARR", ARR },
		{ "FCN", FCN },
		{ "FLD", FLD },
		{ "REC", REC },
		{ "CONVC", CONVC },
		{ "CONVO", CONVO },
		{ NULL, 0 }
	};
	static char buf[100];
	int i;
	char *cp = buf;

	for (i = 0; flagtab[i].name != NULL; i++) {
		if ((flags & flagtab[i].value) != 0) {
			if (cp > buf)
				*cp++ = '|';
			strcpy(cp, flagtab[i].name);
			cp += strlen(cp);
		}
	}

	return buf;
}