/*
 * unpack.c
 * Copyright (C) 1998 Brainchild Design - http://brainchilddesign.com/
 * 
 * Copyright (C) 2001 "timecop" <timecop@japan.co.jp>
 *
 * Copyright (C) 2002 Florian Schulze <crow@icculus.org>
 *
 * This file is part of Jump 'n Bump.
 *
 * Jump 'n Bump 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 2 of the License, or
 * (at your option) any later version.
 *
 * Jump 'n Bump 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, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 */

#include <errno.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#ifndef _WIN32
#include <unistd.h>
#else
#include <io.h>
#endif

typedef struct {
	char filename[12];
	unsigned int offset;
	unsigned int size;
} DirEntry;

#ifndef O_BINARY
#define O_BINARY 0
#endif

int main(int argc, char **argv)
{
	int fd;
	DirEntry *datafile;
	int num_entries, i;

	if (argc < 2) {
		printf("dumbass, specify filename to unpack\n");
		exit(1);
	}

	fd = open(argv[1], O_RDONLY | O_BINARY);
	if (fd == -1) {
		perror("open datafile");
		exit(1);
	}
	/* get number of entries */
	read(fd, &num_entries, 4);

	printf("%d entries in datafile\n", num_entries);

	datafile = calloc(num_entries, sizeof(DirEntry));
	read(fd, datafile, num_entries * sizeof(DirEntry));
	printf("Directory Listing:\n");
	for (i = 0; i < num_entries; i++) {
		char filename[14];
		memset(filename, 0, sizeof(filename));
		strncpy(filename, datafile[i].filename, 12);
		printf("%02d:\t%s (%u bytes)\n", i, filename,
			   datafile[i].size);
	}

	for (i = 0; i < num_entries; i++) {
		int outfd;
		char filename[14];
		char *buf;
		memset(filename, 0, sizeof(filename));
		strncpy(filename, datafile[i].filename, 12);
		printf("Extracting %s ", filename);
		fflush(stdout);

		if (remove(filename) == -1 && errno != ENOENT) {
			perror("cannot remove file");
			exit(1);
		}
		outfd = open(filename, O_RDWR | O_CREAT | O_EXCL | O_BINARY, 0644);
		if (!outfd) {
			perror("cant open file");
			exit(1);
		}
		lseek(fd, datafile[i].offset, SEEK_SET);
		buf = calloc(1, datafile[i].size + 16);
		read(fd, buf, datafile[i].size);
		write(outfd, buf, datafile[i].size);
		close(outfd);
		free(buf);
		printf("OK\n");
	}
	close(fd);
	return 0;
}
