/*
 *  Helper functions for outputting text.
 *  Copyright © 2011 Nick Bowler
 *
 *  This program is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation, either version 3 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
#include <config.h>
#include <stdio.h>
#include <assert.h>

#include "typemap.h"
#include "output.h"
#include "cdecl.h"

size_t cdecl__advance_(char **buf, size_t *n, size_t amount)
{
	if (amount >= *n) {
		*n   = 0;
		*buf = 0;
	} else {
		*buf += amount;
		*n   -= amount;
	}

	return amount;
}

size_t cdecl__advance(char **buf, size_t *n, size_t amount)
{
	size_t ret, rc;

	if (!amount)
		return 0;

	ret = cdecl__advance_(buf, n, amount);
	rc = snprintf(*buf, *n, " ");
	return ret + cdecl__advance_(buf, n, rc);
}

static const char *explain_spec_simple(struct cdecl_declspec *s)
{
	switch (s->type) {
#	include "namespecs.h"
	}

	assert(0);
}

static size_t explain_spec(char *buf, size_t n, struct cdecl_declspec *s)
{
	const char *keyword = explain_spec_simple(s);

	if (keyword[0] && s->ident)
		return snprintf(buf, n, "%s %s", keyword, s->ident);
	else if (s->ident)
		return snprintf(buf, n, "%s", s->ident);
	return snprintf(buf, n, "%s", keyword);
}

/*
 * Render a list of declaration specifiers.  Only the declaration specifiers
 * listed in mask, which is the bitwise OR of the desired specifier kinds, are
 * printed.
 */
size_t cdecl__explain_specs(char *buf, size_t n, struct cdecl_declspec *s,
                                                 unsigned mask)
{
	size_t ret = 0, rc = 0;

	for (struct cdecl_declspec *c = s; c; c = c->next) {
		switch (cdecl_spec_kind(c) & mask) {
		case CDECL_SPEC_FUNC:
		case CDECL_SPEC_STOR:
		case CDECL_SPEC_QUAL:
		case CDECL_SPEC_TYPE:
			ret += cdecl__advance(&buf, &n, rc);
			rc = explain_spec(buf, n, c);
		}
	}

	return ret + rc;
}

/* Renders the storage-class and function specifiers in canonical form. */
size_t cdecl__explain_pre_specs(char *buf, size_t n, struct cdecl_declspec *s)
{
	return cdecl__explain_specs(buf, n, s, CDECL_SPEC_FUNC|CDECL_SPEC_STOR);
}

/* Renders the type qualifiers and type specifiers in canonical form. */
size_t cdecl__explain_post_specs(char *buf, size_t n, struct cdecl_declspec *s)
{
	return cdecl__explain_specs(buf, n, s, CDECL_SPEC_QUAL|CDECL_SPEC_TYPE);
}