/*	$Id$ */
/*
 * Copyright (c) 2008, 2009 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 <sys/types.h>

#include <assert.h>
#include <ctype.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>

#include "libmdoc.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.
 *
 * There's no limit to the number or arguments that may be allocated.
 */

/* FIXME .Bf Li raises "macro-like parameter". */

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

#define	ARGV_NONE	(1 << 0)
#define	ARGV_SINGLE	(1 << 1)
#define	ARGV_MULTI	(1 << 2)
#define	ARGV_OPT_SINGLE	(1 << 3)

#define	MULTI_STEP	 5

static	int		 argv_a2arg(int, const char *);
static	int		 args(struct mdoc *, int, int *, 
				char *, int, char **);
static	int		 argv(struct mdoc *, int, 
				struct mdoc_argv *, int *, char *);
static	int		 argv_single(struct mdoc *, int, 
				struct mdoc_argv *, int *, char *);
static	int		 argv_opt_single(struct mdoc *, int, 
				struct mdoc_argv *, int *, char *);
static	int		 argv_multi(struct mdoc *, int, 
				struct mdoc_argv *, int *, char *);

/* Per-argument flags. */

static	int mdoc_argvflags[MDOC_ARG_MAX] = {
	ARGV_NONE,	/* MDOC_Split */
	ARGV_NONE,	/* MDOC_Nosplit */
	ARGV_NONE,	/* MDOC_Ragged */
	ARGV_NONE,	/* MDOC_Unfilled */
	ARGV_NONE,	/* MDOC_Literal */
	ARGV_NONE,	/* MDOC_File */
	ARGV_SINGLE,	/* MDOC_Offset */
	ARGV_NONE,	/* MDOC_Bullet */
	ARGV_NONE,	/* MDOC_Dash */
	ARGV_NONE,	/* MDOC_Hyphen */
	ARGV_NONE,	/* MDOC_Item */
	ARGV_NONE,	/* MDOC_Enum */
	ARGV_NONE,	/* MDOC_Tag */
	ARGV_NONE,	/* MDOC_Diag */
	ARGV_NONE,	/* MDOC_Hang */
	ARGV_NONE,	/* MDOC_Ohang */
	ARGV_NONE,	/* MDOC_Inset */
	ARGV_MULTI,	/* MDOC_Column */
	ARGV_SINGLE,	/* MDOC_Width */
	ARGV_NONE,	/* MDOC_Compact */
	ARGV_OPT_SINGLE, /* MDOC_Std */
	ARGV_NONE,	/* MDOC_Filled */
	ARGV_NONE,	/* MDOC_Words */
	ARGV_NONE,	/* MDOC_Emphasis */
	ARGV_NONE,	/* MDOC_Symbolic */
	ARGV_NONE	/* MDOC_Symbolic */
};

static	int mdoc_argflags[MDOC_MAX] = {
	0, /* Ap */
	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 */
	0, /* It */
	ARGS_DELIM, /* Ad */ 
	ARGS_DELIM, /* An */
	ARGS_DELIM, /* Ar */
	0, /* Cd */
	ARGS_DELIM, /* Cm */
	ARGS_DELIM, /* Dv */ 
	ARGS_DELIM, /* Er */ 
	ARGS_DELIM, /* Ev */ 
	0, /* Ex */
	ARGS_DELIM, /* Fa */ 
	0, /* Fd */ 
	ARGS_DELIM, /* Fl */
	ARGS_DELIM, /* Fn */ 
	ARGS_DELIM, /* 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 */
	0, /* %A */
	0, /* %B */
	0, /* %D */
	0, /* %I */
	0, /* %J */
	0, /* %N */
	0, /* %O */
	0, /* %P */
	0, /* %R */
	0, /* %T */
	0, /* %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 */
	0, /* Lb */
	ARGS_DELIM, /* Lp */
	ARGS_DELIM, /* Lk */
	ARGS_DELIM, /* Mt */
	ARGS_DELIM, /* Brq */
	0, /* Bro */
	ARGS_DELIM, /* Brc */
	0, /* %C */
	0, /* Es */
	0, /* En */
	0, /* Dx */
	0, /* %Q */
	0, /* br */
	0, /* sp */
};


/*
 * Parse an argument from line text.  This comes in the form of -key
 * [value0...], which may either have a single mandatory value, at least
 * one mandatory value, an optional single value, or no value.
 */
int
mdoc_argv(struct mdoc *m, int line, int tok,
		struct mdoc_arg **v, int *pos, char *buf)
{
	char		 *p, sv;
	struct mdoc_argv tmp;
	struct mdoc_arg	 *arg;

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

	assert(' ' != buf[*pos]);

	/* Parse through to the first unescaped space. */

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

	assert(*pos > 0);

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

	/* XXX - save zeroed byte, if not an argument. */

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

	(void)memset(&tmp, 0, sizeof(struct mdoc_argv));
	tmp.line = line;
	tmp.pos = *pos;

	/* See if our token accepts the argument. */

	if (MDOC_ARG_MAX == (tmp.arg = argv_a2arg(tok, p))) {
		/* XXX - restore saved zeroed byte. */
		if (sv)
			buf[*pos - 1] = sv;
		return(ARGV_WORD);
	}

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

	if ( ! argv(m, line, &tmp, pos, buf))
		return(ARGV_ERROR);

	if (NULL == (arg = *v)) {
		*v = calloc(1, sizeof(struct mdoc_arg));
		if (NULL == *v) {
			(void)mdoc_nerr(m, m->last, EMALLOC);
			return(ARGV_ERROR);
		}
		arg = *v;
	} 

	arg->argc++;
	arg->argv = realloc(arg->argv, arg->argc * 
			sizeof(struct mdoc_argv));

	if (NULL == arg->argv) {
		(void)mdoc_nerr(m, m->last, EMALLOC);
		return(ARGV_ERROR);
	}

	(void)memcpy(&arg->argv[(int)arg->argc - 1], 
			&tmp, sizeof(struct mdoc_argv));

	return(ARGV_ARG);
}


void
mdoc_argv_free(struct mdoc_arg *p)
{
	int		 i, j;

	if (NULL == p)
		return;

	if (p->refcnt) {
		--(p->refcnt);
		if (p->refcnt)
			return;
	}
	assert(p->argc);

	/* LINTED */
	for (i = 0; i < (int)p->argc; i++) {
		if (0 == p->argv[i].sz)
			continue;
		/* LINTED */
		for (j = 0; j < (int)p->argv[i].sz; j++) 
			free(p->argv[i].value[j]);

		free(p->argv[i].value);
	}

	free(p->argv);
	free(p);
}


int
mdoc_args(struct mdoc *m, 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];

	if (MDOC_It != tok)
		return(args(m, line, pos, buf, fl, v));

	/* 
	 * The `It' macro is a special case, as it acquires parameters from its
	 * parent `Bl' context, specifically, we're concerned with -column.
	 */

	for (n = m->last; n; n = n->parent)
		if (MDOC_BLOCK == n->type && MDOC_Bl == n->tok)
			break;

	assert(n);
	c = (int)(n->args ? n->args->argc : 0);
	assert(c > 0);

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

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


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

	assert(*pos);
	assert(' ' != buf[*pos]);

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

	/* 
	 * 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; buf[i]; ) {
			if ( ! mdoc_iscdelim(buf[i]))
				break;
			i++;
			if (0 == buf[i] || ' ' != buf[i])
				break;
			i++;
			while (buf[i] && ' ' == buf[i])
				i++;
		}

		/* FIXME: warn about trailing whitespace. */

		if (0 == buf[i]) {
			*v = &buf[*pos];
			return(ARGS_PUNCT);
		}
	}

	*v = &buf[*pos];

	/*
	 * First handle TABSEP items, restricted to `Bl -column'.  This
	 * ignores conventional token parsing and instead uses tabs or
	 * `Ta' macros to separate phrases.  Phrases are parsed again
	 * for arguments at a later phase.
	 */

	if (ARGS_TABSEP & fl) {
		/* Scan ahead to unescaped tab. */
		p = strchr(*v, '\t');

		/* 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. */
		/* FIXME: escaped 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 += (int)(p - *v);
		} 

		/* Some warnings, if applicable. */
		if (p && 0 == *p)
			if ( ! mdoc_pwarn(m, line, *pos, ECOLEMPTY))
				return(ARGS_ERROR);
		if (p && 0 == *p && p > *v && ' ' == *(p - 1))
			if ( ! mdoc_pwarn(m, line, *pos, ETAILWS))
				return(ARGS_ERROR);

		/* Non-eoln case returns now. */
		if (p)
			return(ARGS_PHRASE);

		/* Configure the eoln case, too. */
		p = strchr(*v, 0);
		assert(p);

		if (p > *v && ' ' == *(p - 1))
			if ( ! mdoc_pwarn(m, line, *pos, ETAILWS))
				return(ARGS_ERROR);
		*pos += (int)(p - *v);

		return(ARGS_PHRASE);
	} 

	/* 
	 * Process a quoted literal.  A quote begins with a double-quote
	 * and ends with a double-quote NOT preceded by a double-quote.
	 * Whitespace is NOT involved in literal termination.
	 */

	if ('\"' == buf[*pos]) {
		*v = &buf[++(*pos)];

		for ( ; buf[*pos]; (*pos)++) {
			if ('\"' != buf[*pos])
				continue;
			if ('\"' != buf[*pos + 1])
				break;
			(*pos)++;
		}

		if (0 == buf[*pos]) {
			if ( ! mdoc_pwarn(m, line, *pos, EQUOTTERM))
				return(ARGS_ERROR);
			return(ARGS_QWORD);
		}

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

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

		while (' ' == buf[*pos])
			(*pos)++;

		if (0 == buf[*pos])
			if ( ! mdoc_pwarn(m, line, *pos, ETAILWS))
				return(ARGS_ERROR);

		return(ARGS_QWORD);
	}

	/* 
	 * A non-quoted term progresses until either the end of line or
	 * a non-escaped whitespace.
	 */

	for ( ; buf[*pos]; (*pos)++)
		if (' ' == buf[*pos] && '\\' != buf[*pos - 1])
			break;

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

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

	while (' ' == buf[*pos])
		(*pos)++;

	if (0 == buf[*pos])
		if ( ! mdoc_pwarn(m, line, *pos, ETAILWS))
			return(ARGS_ERROR);

	return(ARGS_WORD);
}


static int
argv_a2arg(int tok, const char *argv)
{

	/*
	 * Parse an argument identifier from its text.  XXX - this
	 * should really be table-driven to clarify the code.
	 *
	 * If you add an argument to the list, make sure that you
	 * register it here with its one or more macros!
	 */

	switch (tok) {
	case (MDOC_An):
		if (0 == strcmp(argv, "split"))
			return(MDOC_Split);
		else if (0 == strcmp(argv, "nosplit"))
			return(MDOC_Nosplit);
		break;

	case (MDOC_Bd):
		if (0 == strcmp(argv, "ragged"))
			return(MDOC_Ragged);
		else if (0 == strcmp(argv, "unfilled"))
			return(MDOC_Unfilled);
		else if (0 == strcmp(argv, "filled"))
			return(MDOC_Filled);
		else if (0 == strcmp(argv, "literal"))
			return(MDOC_Literal);
		else if (0 == strcmp(argv, "file"))
			return(MDOC_File);
		else if (0 == strcmp(argv, "offset"))
			return(MDOC_Offset);
		else if (0 == strcmp(argv, "compact"))
			return(MDOC_Compact);
		break;

	case (MDOC_Bf):
		if (0 == strcmp(argv, "emphasis"))
			return(MDOC_Emphasis);
		else if (0 == strcmp(argv, "literal"))
			return(MDOC_Literal);
		else if (0 == strcmp(argv, "symbolic"))
			return(MDOC_Symbolic);
		break;

	case (MDOC_Bk):
		if (0 == strcmp(argv, "words"))
			return(MDOC_Words);
		break;

	case (MDOC_Bl):
		if (0 == strcmp(argv, "bullet"))
			return(MDOC_Bullet);
		else if (0 == strcmp(argv, "dash"))
			return(MDOC_Dash);
		else if (0 == strcmp(argv, "hyphen"))
			return(MDOC_Hyphen);
		else if (0 == strcmp(argv, "item"))
			return(MDOC_Item);
		else if (0 == strcmp(argv, "enum"))
			return(MDOC_Enum);
		else if (0 == strcmp(argv, "tag"))
			return(MDOC_Tag);
		else if (0 == strcmp(argv, "diag"))
			return(MDOC_Diag);
		else if (0 == strcmp(argv, "hang"))
			return(MDOC_Hang);
		else if (0 == strcmp(argv, "ohang"))
			return(MDOC_Ohang);
		else if (0 == strcmp(argv, "inset"))
			return(MDOC_Inset);
		else if (0 == strcmp(argv, "column"))
			return(MDOC_Column);
		else if (0 == strcmp(argv, "width"))
			return(MDOC_Width);
		else if (0 == strcmp(argv, "offset"))
			return(MDOC_Offset);
		else if (0 == strcmp(argv, "compact"))
			return(MDOC_Compact);
		else if (0 == strcmp(argv, "nested"))
			return(MDOC_Nested);
		break;
	
	case (MDOC_Rv):
		/* FALLTHROUGH */
	case (MDOC_Ex):
		if (0 == strcmp(argv, "std"))
			return(MDOC_Std);
		break;
	default:
		break;
	}

	return(MDOC_ARG_MAX);
}


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

	for (v->sz = 0; ; v->sz++) {
		if ('-' == buf[*pos])
			break;
		c = args(m, line, pos, buf, 0, &p);
		if (ARGS_ERROR == c)
			return(0);
		else if (ARGS_EOLN == c)
			break;

		if (0 == v->sz % MULTI_STEP) {
			v->value = realloc(v->value, 
				(v->sz + MULTI_STEP) * sizeof(char *));
			if (NULL == v->value) {
				(void)mdoc_nerr(m, m->last, EMALLOC);
				return(ARGV_ERROR);
			}
		}
		if (NULL == (v->value[(int)v->sz] = strdup(p)))
			return(mdoc_nerr(m, m->last, EMALLOC));
	}

	return(1);
}


static int
argv_opt_single(struct mdoc *m, int line, 
		struct mdoc_argv *v, int *pos, char *buf)
{
	int		 c;
	char		*p;

	if ('-' == buf[*pos])
		return(1);

	c = args(m, line, pos, buf, 0, &p);
	if (ARGS_ERROR == c)
		return(0);
	if (ARGS_EOLN == c)
		return(1);

	v->sz = 1;
	if (NULL == (v->value = calloc(1, sizeof(char *))))
		return(mdoc_nerr(m, m->last, EMALLOC));
	if (NULL == (v->value[0] = strdup(p)))
		return(mdoc_nerr(m, m->last, EMALLOC));

	return(1);
}


/*
 * Parse a single, mandatory value from the stream.
 */
static int
argv_single(struct mdoc *m, int line, 
		struct mdoc_argv *v, int *pos, char *buf)
{
	int		 c, ppos;
	char		*p;

	ppos = *pos;

	c = args(m, line, pos, buf, 0, &p);
	if (ARGS_ERROR == c)
		return(0);
	if (ARGS_EOLN == c)
		return(mdoc_perr(m, line, ppos, EARGVAL));

	v->sz = 1;
	if (NULL == (v->value = calloc(1, sizeof(char *))))
		return(mdoc_nerr(m, m->last, EMALLOC));
	if (NULL == (v->value[0] = strdup(p)))
		return(mdoc_nerr(m, m->last, EMALLOC));

	return(1);
}


/*
 * Determine rules for parsing arguments.  Arguments can either accept
 * no parameters, an optional single parameter, one parameter, or
 * multiple parameters.
 */
static int
argv(struct mdoc *mdoc, int line, 
		struct mdoc_argv *v, int *pos, char *buf)
{

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

	switch (mdoc_argvflags[v->arg]) {
	case (ARGV_SINGLE):
		return(argv_single(mdoc, line, v, pos, buf));
	case (ARGV_MULTI):
		return(argv_multi(mdoc, line, v, pos, buf));
	case (ARGV_OPT_SINGLE):
		return(argv_opt_single(mdoc, line, v, pos, buf));
	default:
		/* ARGV_NONE */
		break;
	}

	return(1);
}