/*
 * Main command implementation routines for cdecl99.
 * Copyright © 2011-2012, 2020-2021 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 <https://www.gnu.org/licenses/>.
 */

#include <config.h>
#include <stdio.h>
#include <stdlib.h>

#include "cdecl99.h"
#include "cdecl.h"

/*
 * Format a declaration according to the given function and return a pointer
 * to the formatted string.  The returned pointer remains valid until the
 * next call, after which it must not be re-used.
 *
 * Returns NULL on failure.
 */
static const char *
do_format(size_t func(char *, size_t, struct cdecl *), struct cdecl *decl)
{
	static size_t bufsz;
	static char *buf;

	size_t rc;

retry:
	rc = func(buf, bufsz, decl);
	if (rc >= bufsz) {
		char *tmp;

		tmp = realloc(buf, rc + 1);
		if (!tmp) {
			fprintf(stderr, "%s\n", _("failed to allocate memory"));
			return NULL;
		}

		buf = tmp;
		bufsz = rc + 1;
		goto retry;
	}

	return buf;
}

int run_command_explain(const char *arg)
{
	const struct cdecl_error *err;
	struct cdecl *decl;
	const char *str;
	int ret = -1;

	decl = cdecl_parse_decl(arg);
	if (!decl) {
		err = cdecl_get_error();
		fprintf(stderr, "%s\n", err->str);
		goto out;
	}

	for (struct cdecl *i = decl; i; i = i->next) {
		str = do_format(cdecl_explain, i);
		if (!str)
			goto out;

		printf("%s\n", str);
	}

	ret = 0;
out:
	cdecl_free(decl);
	return ret;
}

int run_command_simplify(const char *arg)
{
	const struct cdecl_error *err;
	struct cdecl *decl;
	const char *str;
	int ret = -1;

	decl = cdecl_parse_decl(arg);
	if (!decl) {
		err = cdecl_get_error();
		fprintf(stderr, "%s\n", err->str);
		goto out;
	}

	for (struct cdecl *i = decl; i; i = i->next) {
		struct cdecl_declspec *s = i->specifiers;

		if (i != decl) {
			i->specifiers = NULL;
			printf(", ");
		}

		str = do_format(cdecl_declare, i);
		i->specifiers = s;

		if (!str)
			goto out;

		printf("%s", str);
	}

	putchar('\n');

	ret = 0;
out:
	cdecl_free(decl);
	return ret;
}

int run_command_declare(const char *cmd)
{
	const struct cdecl_error *err;
	struct cdecl *decl;
	const char *str;
	int ret = -1;

	/* The name of the command is significant here. */
	decl = cdecl_parse_english(cmd);
	if (!decl) {
		err = cdecl_get_error();
		fprintf(stderr, "%s\n", err->str);
		goto out;
	}

	/*
	 * English parses have at most one full declarator, so no loop is
	 * needed here.
	 */
	str = do_format(cdecl_declare, decl);
	if (!str)
		goto out;

	printf("%s\n", str);
	ret = 0;
out:
	cdecl_free(decl);
	return ret;
}