// Shawn Nematbakhsh
// lab wed. 6-9
// 12/5/02
// file system - this program manipluates a MSDOS floppy disk

#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <stdlib.h>
#include <ctype.h>
#include <unistd.h>
#include <string.h>

// mode flags for open files
#define WRITE 0
#define READ 1

// bytes per sector
#define BPS 512

// location of root sector
#define ROOT_SECTOR 19*BPS

// file/directory for f_or_d function
#define FILE_TYPE 0
#define DIRECTORY_TYPE 1

// directory entry - keep track of position + cluster
struct dir_t
{
	int sector;
	int cluster;
};

// file descriptor
struct file_t
{
	char *name;
	int mode;
	int cluster;
	int offset;
	int base;
	long size;
};

// use ints as file desciptors
typedef int FD_Handle;


int fd_load(char driveLetter);
int fd_ls();
char* get_file_name(unsigned char buf[32]);
int fd_cd(char *);
int f_or_d(char *file,unsigned char buf[32],int type);
int is_empty(unsigned char buf[32]);
int fd_rm(char *name);
int next_empty_cluster();
int fd_mkdir(char *name);
int fat_lookup(int cluster);
void sector_clear(int sector);
void fat_set(int cluster,int value);
int fd_mv(char *source,char *destination);
FD_Handle fd_open(char *filename, int mode);
void fd_close(FD_Handle fdHandle);
int fd_read(FD_Handle fdHandle,char *buffer,int length);
int fd_write(FD_Handle fdHandle,char *buffer,int length);
int fd_lseek(FD_Handle fdHandle,int offset);