/* $Id$ */
/*
 * Copyright (c) 2008 Kristaps Dzonsons <kristaps@kth.se>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the
 * above copyright notice and this permission notice appear in all
 * copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL
 * WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE
 * AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, 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.
 */
#include <assert.h>
#include <ctype.h>
#include <err.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>

#include "private.h"

/*
 * Routines to parse arguments of macros.  Arguments follow the syntax
 * of `-arg [val [valN...]]'.  Arguments come in all types:  quoted
 * arguments, multiple arguments per value, no-value arguments, etc.
 */

#define	ARGS_QUOTED	(1 << 0)
#define	ARGS_DELIM	(1 << 1)
#define	ARGS_TABSEP	(1 << 2)

static	int		 lookup(int, const char *);
static	int		 args(struct mdoc *, int, int *, 
				char *, int, char **);
static	int		 argv(struct mdoc *, int,
				struct mdoc_arg *, int *, char *);
static	int		 argv_single(struct mdoc *, int, 
				struct mdoc_arg *, int *, char *);
static	int		 argv_multi(struct mdoc *, int, 
				struct mdoc_arg *, int *, char *);
static	int		 pwarn(struct mdoc *, int, int, int);
static	int		 perr(struct mdoc *, int, int, int);

/* Warning messages. */

#define	WQUOTPARM	(0)
#define	WARGVPARM	(1)
#define	WCOLEMPTY	(2)
#define	WTAILWS		(3)

/* Error messages. */

#define	EQUOTTERM	(0)
#define	EARGVAL		(1)
#define	EARGMANY	(2)

static	int mdoc_argflags[MDOC_MAX] = {
	0, /* \" */
	0, /* Dd */
	0, /* Dt */
	0, /* Os */
	0, /* Sh */
	0, /* Ss */ 
	ARGS_DELIM, /* Pp */ 
	ARGS_DELIM, /* D1 */
	ARGS_DELIM, /* Dl */
	0, /* Bd */
	0, /* Ed */
	0, /* Bl */
	0, /* El */
	ARGS_DELIM, /* It */
	ARGS_DELIM, /* Ad */ 
	ARGS_DELIM, /* An */
	ARGS_DELIM, /* Ar */
	ARGS_QUOTED, /* Cd */
	ARGS_DELIM, /* Cm */
	ARGS_DELIM, /* Dv */ 
	ARGS_DELIM, /* Er */ 
	ARGS_DELIM, /* Ev */ 
	0, /* Ex */
	ARGS_DELIM | ARGS_QUOTED, /* Fa */ 
	0, /* Fd */ 
	ARGS_DELIM, /* Fl */
	ARGS_DELIM | ARGS_QUOTED, /* Fn */ 
	ARGS_DELIM | ARGS_QUOTED, /* Ft */ 
	ARGS_DELIM, /* Ic */ 
	0, /* In */ 
	ARGS_DELIM, /* Li */
	0, /* Nd */ 
	ARGS_DELIM, /* Nm */ 
	ARGS_DELIM, /* Op */
	0, /* Ot */
	ARGS_DELIM, /* Pa */
	0, /* Rv */
	ARGS_DELIM, /* St */ 
	ARGS_DELIM, /* Va */
	ARGS_DELIM, /* Vt */ 
	ARGS_DELIM, /* Xr */
	ARGS_QUOTED, /* %A */
	ARGS_QUOTED, /* %B */
	ARGS_QUOTED, /* %D */
	ARGS_QUOTED, /* %I */
	ARGS_QUOTED, /* %J */
	ARGS_QUOTED, /* %N */
	ARGS_QUOTED, /* %O */
	ARGS_QUOTED, /* %P */
	ARGS_QUOTED, /* %R */
	ARGS_QUOTED, /* %T */
	ARGS_QUOTED, /* %V */
	ARGS_DELIM, /* Ac */
	0, /* Ao */
	ARGS_DELIM, /* Aq */
	ARGS_DELIM, /* At */
	ARGS_DELIM, /* Bc */
	0, /* Bf */ 
	0, /* Bo */
	ARGS_DELIM, /* Bq */
	ARGS_DELIM, /* Bsx */
	ARGS_DELIM, /* Bx */
	0, /* Db */
	ARGS_DELIM, /* Dc */
	0, /* Do */
	ARGS_DELIM, /* Dq */
	ARGS_DELIM, /* Ec */
	0, /* Ef */
	ARGS_DELIM, /* Em */ 
	0, /* Eo */
	ARGS_DELIM, /* Fx */
	ARGS_DELIM, /* Ms */
	ARGS_DELIM, /* No */
	ARGS_DELIM, /* Ns */
	ARGS_DELIM, /* Nx */
	ARGS_DELIM, /* Ox */
	ARGS_DELIM, /* Pc */
	ARGS_DELIM, /* Pf */
	0, /* Po */
	ARGS_DELIM, /* Pq */
	ARGS_DELIM, /* Qc */
	ARGS_DELIM, /* Ql */
	0, /* Qo */
	ARGS_DELIM, /* Qq */
	0, /* Re */
	0, /* Rs */
	ARGS_DELIM, /* Sc */
	0, /* So */
	ARGS_DELIM, /* Sq */
	0, /* Sm */
	ARGS_DELIM, /* Sx */
	ARGS_DELIM, /* Sy */
	ARGS_DELIM, /* Tn */
	ARGS_DELIM, /* Ux */
	ARGS_DELIM, /* Xc */
	0, /* Xo */
	0, /* Fo */ 
	0, /* Fc */ 
	0, /* Oo */
	ARGS_DELIM, /* Oc */
	0, /* Bk */
	0, /* Ek */
	0, /* Bt */
	0, /* Hf */
	0, /* Fr */
	0, /* Ud */
};


static int
perr(struct mdoc *mdoc, int line, int pos, int code)
{
	int		 c;

	switch (code) {
	case (EQUOTTERM):
		c = mdoc_perr(mdoc, line, pos, 
				"unterminated quoted parameter");
		break;
	case (EARGVAL):
		c = mdoc_perr(mdoc, line, pos, 
				"argument requires a value");
		break;
	case (EARGMANY):
		c = mdoc_perr(mdoc, line, pos, 
				"too many values for argument");
		break;
	default:
		abort();
		/* NOTREACHED */
	}
	return(c);
}


static int
pwarn(struct mdoc *mdoc, int line, int pos, int code)
{
	int		 c;

	switch (code) {
	case (WQUOTPARM):
		c = mdoc_pwarn(mdoc, line, pos, WARN_SYNTAX, 
				"unexpected quoted parameter");
		break;
	case (WARGVPARM):
		c = mdoc_pwarn(mdoc, line, pos, WARN_SYNTAX, 
				"argument-like parameter");
		break;
	case (WCOLEMPTY):
		c = mdoc_pwarn(mdoc, line, pos, WARN_SYNTAX, 
				"last list column is empty");
		break;
	case (WTAILWS):
		c = mdoc_pwarn(mdoc, line, pos, WARN_COMPAT, 
				"trailing whitespace");
		break;
	default:
		abort();
		/* NOTREACHED */
	}
	return(c);
}


int
mdoc_args(struct mdoc *mdoc, int line, 
		int *pos, char *buf, int tok, char **v)
{
	int		  fl, c, i;
	struct mdoc_node *n;

	fl = (0 == tok) ? 0 : mdoc_argflags[tok];

	/* 
	 * First see if we should use TABSEP (Bl -column).  This
	 * invalidates the use of ARGS_DELIM.
	 */

	if (MDOC_It == tok) {
		for (n = mdoc->last; n; n = n->parent)
			if (MDOC_BLOCK == n->type)
				if (MDOC_Bl == n->tok)
					break;
		assert(n);
		c = (int)n->data.block.argc;
		assert(c > 0);

		/* LINTED */
		for (i = 0; i < c; i++) {
			if (MDOC_Column != n->data.block.argv[i].arg)
				continue;
			fl |= ARGS_TABSEP;
			fl &= ~ARGS_DELIM;
			break;
		}
	}

	return(args(mdoc, line, pos, buf, fl, v));
}


static int
args(struct mdoc *mdoc, int line, 
		int *pos, char *buf, int fl, char **v)
{
	int		  i, c;
	char		 *p, *pp;

	assert(*pos > 0);

	if (0 == buf[*pos])
		return(ARGS_EOLN);

	if ('\"' == buf[*pos] && ! (fl & ARGS_QUOTED))
		if ( ! pwarn(mdoc, line, *pos, WQUOTPARM))
			return(ARGS_ERROR);

	if ('-' == buf[*pos]) 
		if ( ! pwarn(mdoc, line, *pos, WARGVPARM))
			return(ARGS_ERROR);

	/* 
	 * If the first character is a delimiter and we're to look for
	 * delimited strings, then pass down the buffer seeing if it
	 * follows the pattern of [[::delim::][ ]+]+.
	 */

	if ((fl & ARGS_DELIM) && mdoc_iscdelim(buf[*pos])) {
		for (i = *pos; (c = buf[i]); ) {
			if ( ! mdoc_iscdelim(c))
				break;
			i++;
			if (0 == buf[i] || ! isspace(c))
				break;
			i++;
			while (buf[i] && isspace(c))
				i++;
		}
		if (0 == buf[i]) {
			*v = &buf[*pos];
			return(ARGS_PUNCT);
		}
	}

	/* First parse non-quoted strings. */

	if ('\"' != buf[*pos] || ! (ARGS_QUOTED & fl)) {
		*v = &buf[*pos];

		/* 
		 * Thar be dragons here!  If we're tab-separated, search
		 * ahead for either a tab or the `Ta' macro.  If a tab
		 * is detected, it mustn't be escaped; if a `Ta' is
		 * detected, it must be space-buffered before and after.
		 * If either of these hold true, then prune out the
		 * extra spaces and call it an argument.
		 */

		if (ARGS_TABSEP & fl) {
			/* Scan ahead to unescaped tab. */

			for (p = *v; ; p++) {
				if (NULL == (p = strchr(p, '\t')))
					break;
				if (p == *v)
					break;
				if ('\\' != *(p - 1))
					break;
			}

			/* Scan ahead to unescaped `Ta'. */

			for (pp = *v; ; pp++) {
				if (NULL == (pp = strstr(pp, "Ta")))
					break;
				if (pp > *v && ' ' != *(pp - 1))
					continue;
				if (' ' == *(pp + 2) || 0 == *(pp + 2))
					break;
			}

			/* Choose delimiter tab/Ta. */

			if (p && pp)
				p = (p < pp ? p : pp);
			else if ( ! p && pp)
				p = pp;

			/* Strip delimiter's preceding whitespace. */

			if (p && p > *v) {
				pp = p - 1;
				while (pp > *v && ' ' == *pp)
					pp--;
				if (pp == *v && ' ' == *pp) 
					*pp = 0;
				else if (' ' == *pp)
					*(pp + 1) = 0;
			}

			/* ...in- and proceding whitespace. */

			if (p && ('\t' != *p)) {
				*p++ = 0;
				*p++ = 0;
			} else if (p)
				*p++ = 0;

			if (p) {
				while (' ' == *p)
					p++;
				if (0 != *p)
					*(p - 1) = 0;
				*pos += p - *v;
			} 

			if (p && 0 == *p)
				if ( ! pwarn(mdoc, line, *pos, WCOLEMPTY))
					return(0);
			if (p && 0 == *p && p > *v && ' ' == *(p - 1))
				if ( ! pwarn(mdoc, line, *pos, WTAILWS))
					return(0);

			if (p)
				return(ARGS_WORD);

			/* Configure the eoln case, too. */

			p = strchr(*v, 0);
			assert(p);

			if (p > *v && ' ' == *(p - 1))
				if ( ! pwarn(mdoc, line, *pos, WTAILWS))
					return(0);
			*pos += p - *v;

			return(ARGS_WORD);
		} 

		/* Do non-tabsep look-ahead here. */
		
		if ( ! (ARGS_TABSEP & fl))
			while ((c = buf[*pos])) {
				if (isspace(c))
					if ('\\' != buf[*pos - 1])
						break;
				(*pos)++;
			}

		if (0 == buf[*pos])
			return(ARGS_WORD);

		buf[(*pos)++] = 0;

		if (0 == buf[*pos])
			return(ARGS_WORD);

		if ( ! (ARGS_TABSEP & fl))
			while (buf[*pos] && isspace((int)buf[*pos]))
				(*pos)++;

		if (buf[*pos])
			return(ARGS_WORD);

		if ( ! pwarn(mdoc, line, *pos, WTAILWS))
			return(ARGS_ERROR);

		return(ARGS_WORD);
	}

	/*
	 * If we're a quoted string (and quoted strings are allowed),
	 * then parse ahead to the next quote.  If none's found, it's an
	 * error.  After, parse to the next word.  
	 */

	*v = &buf[++(*pos)];

	while (buf[*pos] && '\"' != buf[*pos])
		(*pos)++;

	if (0 == buf[*pos]) {
		(void)perr(mdoc, line, *pos, EQUOTTERM);
		return(ARGS_ERROR);
	}

	buf[(*pos)++] = 0;
	if (0 == buf[*pos])
		return(ARGS_QWORD);

	while (buf[*pos] && isspace((int)buf[*pos]))
		(*pos)++;

	if (buf[*pos])
		return(ARGS_QWORD);

	if ( ! pwarn(mdoc, line, *pos, WTAILWS))
		return(ARGS_ERROR);

	return(ARGS_QWORD);
}


static int
lookup(int tok, const char *argv)
{

	switch (tok) {
	case (MDOC_An):
		if (xstrcmp(argv, "split"))
			return(MDOC_Split);
		else if (xstrcmp(argv, "nosplit"))
			return(MDOC_Nosplit);
		break;

	case (MDOC_Bd):
		if (xstrcmp(argv, "ragged"))
			return(MDOC_Ragged);
		else if (xstrcmp(argv, "unfilled"))
			return(MDOC_Unfilled);
		else if (xstrcmp(argv, "filled"))
			return(MDOC_Filled);
		else if (xstrcmp(argv, "literal"))
			return(MDOC_Literal);
		else if (xstrcmp(argv, "file"))
			return(MDOC_File);
		else if (xstrcmp(argv, "offset"))
			return(MDOC_Offset);
		break;

	case (MDOC_Bf):
		if (xstrcmp(argv, "emphasis"))
			return(MDOC_Emphasis);
		else if (xstrcmp(argv, "literal"))
			return(MDOC_Literal);
		else if (xstrcmp(argv, "symbolic"))
			return(MDOC_Symbolic);
		break;

	case (MDOC_Bk):
		if (xstrcmp(argv, "words"))
			return(MDOC_Words);
		break;

	case (MDOC_Bl):
		if (xstrcmp(argv, "bullet"))
			return(MDOC_Bullet);
		else if (xstrcmp(argv, "dash"))
			return(MDOC_Dash);
		else if (xstrcmp(argv, "hyphen"))
			return(MDOC_Hyphen);
		else if (xstrcmp(argv, "item"))
			return(MDOC_Item);
		else if (xstrcmp(argv, "enum"))
			return(MDOC_Enum);
		else if (xstrcmp(argv, "tag"))
			return(MDOC_Tag);
		else if (xstrcmp(argv, "diag"))
			return(MDOC_Diag);
		else if (xstrcmp(argv, "hang"))
			return(MDOC_Hang);
		else if (xstrcmp(argv, "ohang"))
			return(MDOC_Ohang);
		else if (xstrcmp(argv, "inset"))
			return(MDOC_Inset);
		else if (xstrcmp(argv, "column"))
			return(MDOC_Column);
		else if (xstrcmp(argv, "width"))
			return(MDOC_Width);
		else if (xstrcmp(argv, "offset"))
			return(MDOC_Offset);
		else if (xstrcmp(argv, "compact"))
			return(MDOC_Compact);
		break;
	
	case (MDOC_Rv):
		/* FALLTHROUGH */
	case (MDOC_Ex):
		if (xstrcmp(argv, "std"))
			return(MDOC_Std);
		break;
	
	case (MDOC_St):
		if (xstrcmp(argv, "p1003.1-88"))
			return(MDOC_p1003_1_88);
		else if (xstrcmp(argv, "p1003.1-90"))
			return(MDOC_p1003_1_90);
		else if (xstrcmp(argv, "p1003.1-96"))
			return(MDOC_p1003_1_96);
		else if (xstrcmp(argv, "p1003.1-2001"))
			return(MDOC_p1003_1_2001);
		else if (xstrcmp(argv, "p1003.1-2004"))
			return(MDOC_p1003_1_2004);
		else if (xstrcmp(argv, "p1003.1"))
			return(MDOC_p1003_1);
		else if (xstrcmp(argv, "p1003.1b"))
			return(MDOC_p1003_1b);
		else if (xstrcmp(argv, "p1003.1b-93"))
			return(MDOC_p1003_1b_93);
		else if (xstrcmp(argv, "p1003.1c-95"))
			return(MDOC_p1003_1c_95);
		else if (xstrcmp(argv, "p1003.1g-2000"))
			return(MDOC_p1003_1g_2000);
		else if (xstrcmp(argv, "p1003.2-92"))
			return(MDOC_p1003_2_92);
		else if (xstrcmp(argv, "p1003.2-95"))
			return(MDOC_p1387_2_95);
		else if (xstrcmp(argv, "p1003.2"))
			return(MDOC_p1003_2);
		else if (xstrcmp(argv, "p1387.2-95"))
			return(MDOC_p1387_2);
		else if (xstrcmp(argv, "isoC-90"))
			return(MDOC_isoC_90);
		else if (xstrcmp(argv, "isoC-amd1"))
			return(MDOC_isoC_amd1);
		else if (xstrcmp(argv, "isoC-tcor1"))
			return(MDOC_isoC_tcor1);
		else if (xstrcmp(argv, "isoC-tcor2"))
			return(MDOC_isoC_tcor2);
		else if (xstrcmp(argv, "isoC-99"))
			return(MDOC_isoC_99);
		else if (xstrcmp(argv, "ansiC"))
			return(MDOC_ansiC);
		else if (xstrcmp(argv, "ansiC-89"))
			return(MDOC_ansiC_89);
		else if (xstrcmp(argv, "ansiC-99"))
			return(MDOC_ansiC_99);
		else if (xstrcmp(argv, "ieee754"))
			return(MDOC_ieee754);
		else if (xstrcmp(argv, "iso8802-3"))
			return(MDOC_iso8802_3);
		else if (xstrcmp(argv, "xpg3"))
			return(MDOC_xpg3);
		else if (xstrcmp(argv, "xpg4"))
			return(MDOC_xpg4);
		else if (xstrcmp(argv, "xpg4.2"))
			return(MDOC_xpg4_2);
		else if (xstrcmp(argv, "xpg4.3"))
			return(MDOC_xpg4_3);
		else if (xstrcmp(argv, "xbd5"))
			return(MDOC_xbd5);
		else if (xstrcmp(argv, "xcu5"))
			return(MDOC_xcu5);
		else if (xstrcmp(argv, "xsh5"))
			return(MDOC_xsh5);
		else if (xstrcmp(argv, "xns5"))
			return(MDOC_xns5);
		else if (xstrcmp(argv, "xns5.2d2.0"))
			return(MDOC_xns5_2d2_0);
		else if (xstrcmp(argv, "xcurses4.2"))
			return(MDOC_xcurses4_2);
		else if (xstrcmp(argv, "susv2"))
			return(MDOC_susv2);
		else if (xstrcmp(argv, "susv3"))
			return(MDOC_susv3);
		else if (xstrcmp(argv, "svid4"))
			return(MDOC_svid4);
		break;

	default:
		break;
	}

	return(MDOC_ARG_MAX);
}


static int
argv_multi(struct mdoc *mdoc, int line, 
		struct mdoc_arg *v, int *pos, char *buf)
{
	int		 c, ppos;
	char		*p;

	v->sz = 0;
	v->value = xcalloc(MDOC_LINEARG_MAX, sizeof(char *));

	ppos = *pos;

	for (v->sz = 0; v->sz < MDOC_LINEARG_MAX; v->sz++) {
		if ('-' == buf[*pos])
			break;
		c = args(mdoc, line, pos, buf, ARGS_QUOTED, &p);
		if (ARGS_ERROR == c) {
			free(v->value);
			return(0);
		} else if (ARGS_EOLN == c)
			break;
		v->value[v->sz] = p;
	}

	if (0 < v->sz && v->sz < MDOC_LINEARG_MAX)
		return(1);

	free(v->value);
	if (0 == v->sz) 
		return(perr(mdoc, line, ppos, EARGVAL));

	return(perr(mdoc, line, ppos, EARGMANY));
}


static int
argv_single(struct mdoc *mdoc, int line, 
		struct mdoc_arg *v, int *pos, char *buf)
{
	int		 c, ppos;
	char		*p;

	ppos = *pos;

	c = args(mdoc, line, pos, buf, ARGS_QUOTED, &p);
	if (ARGS_ERROR == c)
		return(0);
	if (ARGS_EOLN == c)
		return(perr(mdoc, line, ppos,  EARGVAL));

	v->sz = 1;
	v->value = xcalloc(1, sizeof(char *));
	v->value[0] = p;
	return(1);
}


static int
argv(struct mdoc *mdoc, int line, 
		struct mdoc_arg *v, int *pos, char *buf)
{

	v->sz = 0;
	v->value = NULL;

	switch (v->arg) {
	case(MDOC_Std):
		/* FALLTHROUGH */
	case(MDOC_Width):
		/* FALLTHROUGH */
	case(MDOC_Offset):
		return(argv_single(mdoc, line, v, pos, buf));
	case(MDOC_Column):
		return(argv_multi(mdoc, line, v, pos, buf));
	default:
		break;
	}

	return(1);
}


int
mdoc_argv(struct mdoc *mdoc, int line, int tok,
		struct mdoc_arg *v, int *pos, char *buf)
{
	int		 i, ppos;
	char		*p;

	(void)memset(v, 0, sizeof(struct mdoc_arg));

	if (0 == buf[*pos])
		return(ARGV_EOLN);

	assert( ! isspace((int)buf[*pos]));

	if ('-' != buf[*pos])
		return(ARGV_WORD);

	i = *pos;
	p = &buf[++(*pos)];

	v->line = line;
	v->pos = *pos;

	assert(*pos > 0);

	/* LINTED */
	while (buf[*pos]) {
		if (isspace((int)buf[*pos])) 
			if ('\\' != buf[*pos - 1])
				break;
		(*pos)++;
	}

	if (buf[*pos])
		buf[(*pos)++] = 0;

	if (MDOC_ARG_MAX == (v->arg = lookup(tok, p))) {
		if ( ! pwarn(mdoc, line, i, WARGVPARM))
			return(ARGV_ERROR);
		return(ARGV_WORD);
	}

	while (buf[*pos] && isspace((int)buf[*pos]))
		(*pos)++;

	/* FIXME: whitespace if no value. */

	ppos = *pos;
	if ( ! argv(mdoc, line, v, pos, buf))
		return(ARGV_ERROR);

	return(ARGV_ARG);
}


void
mdoc_argv_free(int sz, struct mdoc_arg *arg)
{
	int		 i;

	for (i = 0; i < sz; i++) {
		if (0 == arg[i].sz) {
			assert(NULL == arg[i].value);
			continue;
		}
		assert(arg[i].value);
		free(arg[i].value);
	}
}