/*
 * 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 <http://www.gnu.org/licenses/>.
 */

#include <stdio.h>
#include <stdlib.h>
#include "defs.h"
#include "gzip.h"
#include "ustar.h"

#define OPKG_OPK_MAIN_FILE_BUFFER_SIZE_ 8192

struct _opkg_opk_main_file {
	FILE *file;
	char  buffer[OPKG_OPK_MAIN_FILE_BUFFER_SIZE_];
};

static int
_opkg_opk_main_file_read(void *user_data, char **buffer, size_t *size)
{
	struct _opkg_opk_main_file *file = user_data;

	*buffer = file->buffer;
	*size   = fread(file->buffer, 1, OPKG_OPK_MAIN_FILE_BUFFER_SIZE_,
			file->file);
	if (feof(file->file)) {
		return OPKG_OPK_END;
	} else if (ferror(file->file) || *size == 0) {
		return OPKG_OPK_ERROR;
	} else {
		return OPKG_OPK_OK;
	}
}

static int
_opkg_opk_main_extract(const char *file_name, const char *outer_member,
		int (*inner_action)(struct opkg_opk_ustar *))
{
	struct _opkg_opk_main_file    file;
	struct opkg_opk_gzip         *outer_gzip;
	struct opkg_opk_ustar        *outer_ustar;
	struct opkg_opk_gzip         *inner_gzip;
	struct opkg_opk_ustar        *inner_ustar;

	file.file = fopen(file_name, "rb");
	if (file.file == NULL) {
		return OPKG_OPK_ERROR;
	}

	outer_gzip = opkg_opk_gzip_init(&_opkg_opk_main_file_read, &file);
	if (outer_gzip == NULL) {
		fclose(file.file);
		return OPKG_OPK_ERROR;
	}

	outer_ustar = opkg_opk_ustar_init(outer_gzip);
	if (outer_ustar == NULL) {
		opkg_opk_gzip_free(outer_gzip);
		fclose(file.file);
		return OPKG_OPK_ERROR;
	}

	opkg_opk_ustar_seek(outer_ustar, outer_member);
	inner_gzip = opkg_opk_gzip_init(&opkg_opk_ustar_read, outer_ustar);
	if (inner_gzip == NULL) {
		opkg_opk_ustar_free(outer_ustar);
		opkg_opk_gzip_free(outer_gzip);
		fclose(file.file);
		return OPKG_OPK_ERROR;
	}

	inner_ustar = opkg_opk_ustar_init(inner_gzip);
	if (inner_ustar == NULL) {
		opkg_opk_gzip_free(inner_gzip);
		opkg_opk_ustar_free(outer_ustar);
		opkg_opk_gzip_free(outer_gzip);
		fclose(file.file);
		return OPKG_OPK_ERROR;
	}

	inner_action(inner_ustar);

	opkg_opk_ustar_free(inner_ustar);
	opkg_opk_gzip_free(inner_gzip);
	opkg_opk_ustar_free(outer_ustar);
	opkg_opk_gzip_free(outer_gzip);
	fclose(file.file);

	return OPKG_OPK_OK;
}

static int
_opkg_opk_main_read_control(struct opkg_opk_ustar *ustar)
{
	char    buffer[OPKG_OPK_USTAR_RECORD_SIZE];
	size_t  size;
	int     ret;

	opkg_opk_ustar_seek(ustar, "control");
	while ((ret = opkg_opk_ustar_read(ustar, &buffer, &size)) ==
			OPKG_OPK_OK) {
		fwrite(buffer, 1, size, stdout);
	}
	if (ret == OPKG_OPK_ERROR) {
		return OPKG_OPK_ERROR;
	}

	return OPKG_OPK_OK;
}

static int
_opkg_opk_main_list_members(struct opkg_opk_ustar *ustar)
{
	struct opkg_opk_ustar_member  member;
	int                           ret;

	while ((ret = opkg_opk_ustar_list(ustar, &member)) == OPKG_OPK_OK) {
		puts(member.name);
	}
	if (ret == OPKG_OPK_ERROR) {
		return OPKG_OPK_ERROR;
	}

	return OPKG_OPK_OK;
}

int
main(int argc, char *argv[])
{
//	if (_opkg_opk_main_extract(argv[1], "control.tar.gz",
//			&_opkg_opk_main_read_control) != OPKG_OPK_OK) {
//		return EXIT_FAILURE;
//	}
//	puts("");
	if (_opkg_opk_main_extract(argv[1], "data.tar.gz",
			&_opkg_opk_main_list_members) != OPKG_OPK_OK) {
		return EXIT_FAILURE;
	}

	return EXIT_SUCCESS;
}