/*
 * Copyright (C) 2023  Patrick McDermott
 *
 * This file is part of opkg-opk.
 *
 * opkg-opk 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.
 *
 * opkg-opk 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 opkg-opk.  If not, see <https://www.gnu.org/licenses/>.
 */

#include <inttypes.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "defs.h"
#include "specials.h"

struct opkg_opk_specials {
	char                      type;
	uint32_t                  devmajor;
	uint32_t                  devminor;
	char                     *name;
	struct opkg_opk_specials *next;
};

static int
_opkg_opk_specials_read_v1(FILE *fp, struct opkg_opk_specials **specials)
{
	struct opkg_opk_specials *special;

	*specials = NULL;
	fscanf(fp, "%*[^\n]\n");  /* Header line */
	while (feof(fp) == 0) {
		special = malloc(sizeof(*special));
		if (special == NULL) {
			opkg_opk_specials_free(*specials);
			return OPKG_OPK_ERROR;
		}
/*		POSIX specifies the assignment-allocation character 'm', but ISO
 *		C doesn't, so GCC prints a warning. */
#		pragma GCC diagnostic push
#		pragma GCC diagnostic ignored "-Wformat"
		if (fscanf(fp, " %c %" SCNu32 " %" SCNu32 " %ms \n",
					&special->type,
					&special->devmajor, &special->devminor,
					&special->name) != 4) {
#		pragma GCC diagnostic pop
			opkg_opk_specials_free(*specials);
			return OPKG_OPK_ERROR;
		}
		if (special->type != 'c' && special->type != 'b') {
			opkg_opk_specials_free(*specials);
			return OPKG_OPK_ERROR;
		}
		special->next = *specials;
		*specials = special;
	}

	return OPKG_OPK_OK;
}

int
opkg_opk_specials_read(const char *file_name,
		struct opkg_opk_specials **specials)
{
	FILE         *fp;
	unsigned int  version;

	fp = fopen(file_name, "r");
	if (fp == NULL) {
		return OPKG_OPK_ERROR;
	}
	if (fscanf(fp, " version = %u \n", &version) != 1) {
		fclose(fp);
		return OPKG_OPK_ERROR;
	}
	switch (version) {
		case 1U:
			if (_opkg_opk_specials_read_v1(fp, specials) !=
					OPKG_OPK_OK) {
				fclose(fp);
				return OPKG_OPK_ERROR;
			}
			break;
		default:
			fclose(fp);
			return OPKG_OPK_ERROR;
	}

	fclose(fp);  /* Just reading, so OK to ignore errors */
	return OPKG_OPK_OK;
}

int
opkg_opk_specials_find(struct opkg_opk_specials *specials, const char *find,
		char *type, uint32_t *devmajor, uint32_t *devminor)
{
	for (; specials != NULL; specials = specials->next) {
		if (strcmp(find, specials->name) == 0) {
			*type     = specials->type;
			*devmajor = specials->devmajor;
			*devminor = specials->devminor;
			return OPKG_OPK_OK;
		}
	}

	return OPKG_OPK_END;
}

void
opkg_opk_specials_free(struct opkg_opk_specials *specials)
{
	struct opkg_opk_specials *special;

	while (specials != NULL) {
		special = specials;
		specials = specials->next;
		free(special->name);
		free(special);
	}
}