/*
 * Generate random C declarations for testing.
 * Copyright © 2012, 2020, 2022-2024 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 <string.h>
#include <assert.h>
#include <stdbool.h>
#include <errno.h>
#include <getopt.h>

#include "cdecl.h"
#include "declgen.h"

#define PROGNAME "randomdecl"
#include "test.h"

static const char sopts[] = "s:n:ECVH";
static const struct option lopts[] = {
	{ "seed",    1, NULL, 's' },
	{ "count",   1, NULL, 'n' },
	{ "cdecl",   0, NULL, 'C' },
	{ "english", 0, NULL, 'E' },
	{ "version", 0, NULL, 'V' },
	{ "help",    0, NULL, 'H' },
	{ 0 }
};

enum {
	MODE_CDECL,
	MODE_ENGLISH
};

static void print_usage(FILE *f)
{
	fprintf(f, "Usage: %s [options]\n", progname);
}

static void print_help(void)
{
	const struct option *opt;

	print_usage(stdout);
	puts("Generate random C declarations for testing.\n");
	test_print_options(lopts);
}

static struct cdecl *random_decl(struct test_rng *rng)
{
	struct cdecl *decl;
	unsigned flags = 0;

	decl = malloc_nofail(sizeof *decl);
	decl->next = NULL;

	decl->declarators = gen_declarators(rng);
	if (decl->declarators->type != CDECL_DECL_FUNCTION)
		flags |= GEN_NO_FUNCTION;
	if (cdecl_is_abstract(decl->declarators))
		flags |= GEN_NO_STORAGE | GEN_NO_FUNCTION;
	if (decl->declarators->type == CDECL_DECL_ARRAY
	    || decl->declarators->type == CDECL_DECL_IDENT)
		flags |= GEN_NO_VOID;

	decl->specifiers = gen_declspecs(rng, flags);
	return decl;
}

static void
print_decl(struct cdecl *decl, size_t func(char *, size_t, struct cdecl *))
{
	static size_t printbuf_size;
	static char *printbuf;
	size_t rc;
retry:
	rc = func(printbuf, printbuf_size, decl);
	if (rc >= printbuf_size) {
		printbuf_size = rc + 1;
		printbuf = realloc_nofail(printbuf, printbuf_size);
		goto retry;
	}

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

int main(int argc, char **argv)
{
	const char *seed = "", *count_str = NULL;
	unsigned long i, count = 0;
	int opt, mode = MODE_CDECL;
	struct test_rng *rng;
	struct cdecl *decl;

	if (argc > 0)
		progname = argv[0];

	while ((opt = getopt_long(argc, argv, sopts, lopts, NULL)) != -1) {
		switch (opt) {
		case 's':
			seed = optarg;
			break;
		case 'n':
			count_str = optarg;
			break;
		case 'C':
			mode = MODE_CDECL;
			break;
		case 'E':
			mode = MODE_ENGLISH;
			break;
		case 'V':
			test_print_version(PROGNAME);
			return EXIT_SUCCESS;
		case 'H':
			print_help();
			return EXIT_SUCCESS;
		default:
			print_usage(stderr);
			return EXIT_FAILURE;
		}
	}

	if (count_str && !test_strtoul(&count, count_str)) {
		print_error("invalid count: %s", count_str);
		return EXIT_FAILURE;
	}

	rng = test_rng_alloc(seed);
	if (!rng)
		return EXIT_FAILURE;

	for (i = 0; !count || i < count; i++) {
		decl = random_decl(rng);

		if (mode == MODE_ENGLISH) {
			print_decl(decl, cdecl_explain);
		} else {
			print_decl(decl, cdecl_declare);
		}

		gen_free_declspecs(decl->specifiers);
		gen_free_declarators(decl->declarators);
		free(decl);
	}

	test_rng_free(rng);

	return EXIT_SUCCESS;
}