/*
	gba_nds_fat.h
	By chishm (Michael Chisholm)

	Routines for reading a compact flash card
	using the GBA Movie Player or M3.

	Some FAT routines are based on those in fat.c, which
	is part of avrlib by Pascal Stang.

	This software is completely free. No warranty is provided.
	If you use it, please give me credit and email me about your
	project at chishm@hotmail.com

	See gba_nds_fat.txt for help and license details.
*/

//---------------------------------------------------------------

#ifndef _GBA_NDS_FAT_INCLUDED
#define _GBA_NDS_FAT_INCLUDED

//---------------------------------------------------------------
// Customisable features

// Maximum number of files open at once
// Increase this to open more files, decrease to save memory
#define MAX_FILES_OPEN	16

// Allow file writing
// Disable this to remove file writing support
#define CAN_WRITE_TO_DISC

// Allow file time functions
// This adds ~ 14KB to the compiled size
// Uncomment to enable
// #define FILE_TIME_SUPPORT

//---------------------------------------------------------------
// Platform specific includes

// When compiling for NDS, make sure NDS is defined
#ifndef NDS
 #if defined ARM9 || defined ARM7
  #define NDS
 #endif
#endif

#ifdef NDS
 #include <nds/ndstypes.h>
#else
 #include "gba_types.h"
#endif

#ifdef FILE_TIME_SUPPORT
 #include <time.h>
#endif

//---------------------------------------------------------------
#ifdef __cplusplus
extern "C" {
#endif
//---------------------------------------------------------------

//---------------------------------------------------------------
// Important constants


enum {
	MAX_FILENAME_LENGTH = 256	// Maximum LFN length. Don't change this one
};

// File Constants
#ifndef EOF
#define EOF -1
#define SEEK_SET	0
#define SEEK_CUR	1
#define SEEK_END	2
#endif

// File attributes
#define ATTRIB_ARCH	0x20			// Archive
#define ATTRIB_DIR	0x10			// Directory
#define ATTRIB_LFN	0x0F			// Long file name
#define ATTRIB_VOL	0x08			// Volume
#define ATTRIB_SYS	0x04			// System
#define ATTRIB_HID	0x02			// Hidden
#define ATTRIB_RO	0x01			// Read only


// Directory Constants
typedef enum {FT_NONE, FT_FILE, FT_DIR} FILE_TYPE;

// Filesystem type
typedef enum {FS_UNKNOWN, FS_FAT12, FS_FAT16, FS_FAT32} FS_TYPE;

// Open file information structure
typedef struct
{
	u32 firstCluster;
	u32 length;
	u32 curPos;
	u32 curClus;			// Current cluster to read from
	int curSect;			// Current sector within cluster
	int curByte;			// Current byte within sector
	char readBuffer[512];	// Buffer used for unaligned reads
	u32 appClus;			// Cluster to append to
	int appSect;			// Sector within cluster for appending
	int appByte;			// Byte within sector for appending
	bool read;	// Can read from file
	bool write;	// Can write to file
	bool append;// Can append to file
	bool inUse;	// This file is open
	u32 dirEntSector;	// The sector where the directory entry is stored
	int dirEntOffset;	// The offset within the directory sector
}	FAT_FILE;


//-----------------------------------------------------------------
// CF Card functions

/*-----------------------------------------------------------------
FAT_InitFiles
Reads the FAT information from the CF card.
You need to call this before reading any files.
bool return OUT: true if successful.
-----------------------------------------------------------------*/
bool FAT_InitFiles (void);

/*-----------------------------------------------------------------
FAT_FreeFiles
Closes all open files then resets the CF card.
Call this before exiting back to the GBAMP
bool return OUT: true if successful.
-----------------------------------------------------------------*/
bool FAT_FreeFiles (void);

/*-----------------------------------------------------------------
FAT_GetAlias
Get the alias (short name) of the last file or directory entry read
	using GetDirEntry. Works for FindFirstFile and FindNextFile
char* alias OUT: will be filled with the alias (short filename),
	should be at least 13 bytes long
bool return OUT: return true if successful
-----------------------------------------------------------------*/
bool FAT_GetAlias (char* alias);

/*-----------------------------------------------------------------
FAT_GetLongFilename
Get the long name of the last file or directory retrived with
	GetDirEntry. Also works for FindFirstFile and FindNextFile
char* filename: OUT will be filled with the filename, should be at
	least 256 bytes long
bool return OUT: return true if successful
-----------------------------------------------------------------*/
bool FAT_GetLongFilename (char* filename);

/*-----------------------------------------------------------------
FAT_GetFileSize
Get the file size of the last file found or openned.
This idea is based on a modification by MoonShine
u32 return OUT: the file size
-----------------------------------------------------------------*/
u32 FAT_GetFileSize (void);

/*-----------------------------------------------------------------
FAT_GetFileCluster
Get the first cluster of the last file found or openned.
u32 return OUT: the file start cluster
-----------------------------------------------------------------*/
u32 FAT_GetFileCluster (void);

/*-----------------------------------------------------------------
FAT_GetFileAttributes
Get the attributes of the last file found or openned.
u8 return OUT: the file's attributes
-----------------------------------------------------------------*/
u8 FAT_GetFileAttributes (void);

#ifdef CAN_WRITE_TO_DISC
/*-----------------------------------------------------------------
FAT_FAT_SetFileAttributes
Set the attributes of a file.
const char* filename IN: The name and path of the file to modify
u8 attributes IN: The attribute values to assign
u8 mask IN: Detemines which attributes are changed
u8 return OUT: the file's new attributes
-----------------------------------------------------------------*/
u8 FAT_SetFileAttributes (const char* filename, u8 attributes, u8 mask);
#endif

#ifdef FILE_TIME_SUPPORT
/*-----------------------------------------------------------------
FAT_GetFileCreationTime
Get the creation time of the last file found or openned.
time_t return OUT: the file's creation time
-----------------------------------------------------------------*/
time_t FAT_GetFileCreationTime (void);

/*-----------------------------------------------------------------
FAT_GetFileLastWriteTime
Get the creation time of the last file found or openned.
time_t return OUT: the file's creation time
-----------------------------------------------------------------*/
time_t FAT_GetFileLastWriteTime (void);
#endif

/*-----------------------------------------------------------------
FAT_FindNextFile
Gets the name of the next directory entry
	(can be a file or subdirectory)
char* filename: OUT filename, must be at least 13 chars long
FILE_TYPE return: OUT returns FT_NONE if failed,
	FT_FILE if it found a file and FT_DIR if it found a directory
-----------------------------------------------------------------*/
FILE_TYPE FAT_FindNextFile (char* filename);

/*-----------------------------------------------------------------
FAT_FindFirstFile
Gets the name of the first directory entry and resets the count
	(can be a file or subdirectory)
char* filename: OUT filename, must be at least 13 chars long
FILE_TYPE return: OUT returns FT_NONE if failed,
	FT_FILE if it found a file and FT_DIR if it found a directory
-----------------------------------------------------------------*/
FILE_TYPE FAT_FindFirstFile (char* filename);

/*-----------------------------------------------------------------
FAT_FindFirstFileLFN
Gets the long file name of the first directory entry and resets
	the count (can be a file or subdirectory)
char* lfn: OUT long file name, must be at least 256 chars long
FILE_TYPE return: OUT returns FT_NONE if failed,
	FT_FILE if it found a file and FT_DIR if it found a directory
-----------------------------------------------------------------*/
FILE_TYPE FAT_FindFirstFileLFN(char* lfn);

/*-----------------------------------------------------------------
FAT_FindNextFileLFN
Gets the long file name of the next directory entry
	(can be a file or subdirectory)
char* lfn: OUT long file name, must be at least 256 chars long
FILE_TYPE return: OUT returns FT_NONE if failed,
	FT_FILE if it found a file and FT_DIR if it found a directory
-----------------------------------------------------------------*/
FILE_TYPE FAT_FindNextFileLFN(char* lfn);

/*-----------------------------------------------------------------
FAT_FileExists
Returns the type of file
char* filename: IN filename of the file to look for
FILE_TYPE return: OUT returns FT_NONE if there is now file with
	that name, FT_FILE if it is a file and FT_DIR if it is a directory
-----------------------------------------------------------------*/
FILE_TYPE FAT_FileExists (const char* filename);

/*-----------------------------------------------------------------
FAT_GetFileSystemType
FS_TYPE return: OUT returns the current file system type
-----------------------------------------------------------------*/
FS_TYPE FAT_GetFileSystemType (void);

/*-----------------------------------------------------------------
FAT_GetFileSystemTotalSize
u32 return: OUT returns the total disk space (used + free)
-----------------------------------------------------------------*/
u32 FAT_GetFileSystemTotalSize (void);

/*-----------------------------------------------------------------
FAT_chdir
Changes the current working directory
const char* path: IN null terminated string of directory separated by
	forward slashes, / is root
bool return: OUT returns true if successful
-----------------------------------------------------------------*/
bool FAT_chdir (const char* path);


//-----------------------------------------------------------------
// File functions

/*-----------------------------------------------------------------
FAT_fopen(filename, mode)
Opens a file
const char* path: IN null terminated string of filename and path
	separated by forward slashes, / is root
const char* mode: IN mode to open file in
	Supported modes: "r", "r+", "w", "w+", "a", "a+", don't use
	"b" or "t" in any mode, as all files are openned in binary mode
FAT_FILE* return: OUT handle to open file, returns -1 if the file
	couldn't be openned
-----------------------------------------------------------------*/
FAT_FILE* FAT_fopen(const char* path, const char* mode);

/*-----------------------------------------------------------------
FAT_fclose(file)
Closes a file
FAT_FILE* file: IN handle of the file to close
bool return OUT: true if successful, false if not
-----------------------------------------------------------------*/
bool FAT_fclose (FAT_FILE* file);

/*-----------------------------------------------------------------
FAT_ftell(file)
Returns the current position in a file
FAT_FILE* file: IN handle of an open file
u32 OUT: Current position
-----------------------------------------------------------------*/
u32 FAT_ftell (FAT_FILE* file);

/*-----------------------------------------------------------------
FAT_fseek(file, offset, origin)
Seeks to specified byte position in file
int file: IN handle of an open file
u32 offset IN: position to seek to, relative to origin
int origin IN: origin to seek from
int OUT: Returns 0 if successful, -1 if not
-----------------------------------------------------------------*/
int FAT_fseek(FAT_FILE* file, s32 offset, int origin);

/*-----------------------------------------------------------------
FAT_fread(buffer, size, count, file)
Reads in length number of bytes into buffer from file, starting
	from current position. It then sets the current position to the
	byte after the last byte read. If it reaches the end of file
	before filling the buffer then it stops reading.
void* buffer OUT: Pointer to buffer to fill. Should be at least as
	big as the number of bytes required
u32 size IN: size of each item to read
u32 count IN: number of items to read
FAT_FILE* file IN: Handle of an open file
u32 OUT: returns the actual number of bytes read
-----------------------------------------------------------------*/
u32 FAT_fread (void* buffer, u32 size, u32 count, FAT_FILE* file);

#ifdef CAN_WRITE_TO_DISC
/*-----------------------------------------------------------------
FAT_fwrite(buffer, size, count, file)
Writes size * count bytes into file from buffer, starting
	from current position. It then sets the current position to the
	byte after the last byte written. If the file was openned in
	append mode it always writes to the end of the file.
const void* buffer IN: Pointer to buffer containing data. Should be
	at least as big as the number of bytes to be written.
u32 size IN: size of each item to write
u32 count IN: number of items to write
FAT_FILE* file IN: Handle of an open file
u32 OUT: returns the actual number of bytes written
-----------------------------------------------------------------*/
u32 FAT_fwrite (const void* buffer, u32 size, u32 count, FAT_FILE* file);
#endif

/*-----------------------------------------------------------------
FAT_feof(file)
Returns true if the end of file has been reached
FAT_FILE* file IN: Handle of an open file
bool return OUT: true if EOF, false if not
-----------------------------------------------------------------*/
bool FAT_feof(FAT_FILE* file);

#ifdef CAN_WRITE_TO_DISC
/*-----------------------------------------------------------------
FAT_remove (path)
Deletes the file or empty directory sepecified in path
const char* path IN: Path of item to delete
int return OUT: zero if successful, non-zero if not
-----------------------------------------------------------------*/
int FAT_remove (const char* path);
#endif

#ifdef CAN_WRITE_TO_DISC
/*-----------------------------------------------------------------
FAT_mkdir (path)
Makes a new directory, so long as no other directory or file has
	the same name.
const char* path IN: Path and filename of directory to make
int return OUT: zero if successful, non-zero if not
-----------------------------------------------------------------*/
int FAT_mkdir (const char* path);
#endif

/*-----------------------------------------------------------------
FAT_fgetc (handle)
Gets the next character in the file
FAT_FILE* file IN: Handle of open file
bool return OUT: character if successful, EOF if not
-----------------------------------------------------------------*/
char FAT_fgetc (FAT_FILE* file);

#ifdef CAN_WRITE_TO_DISC
/*-----------------------------------------------------------------
FAT_fputc (character, handle)
Writes the given character into the file
char c IN: Character to be written
FAT_FILE* handle IN: Handle of open file
bool return OUT: character if successful, EOF if not
-----------------------------------------------------------------*/
char FAT_fputc (char c, FAT_FILE* file);
#endif

/*-----------------------------------------------------------------
FAT_fgets (char *tgtBuffer, int num, FAT_FILE* file)
Gets a up to num bytes from file, stopping at the first
 newline.

CAUTION: does not do strictly streaming. I.e. it's
 reading more then needed bytes and seeking back.
 shouldn't matter for random access

char *tgtBuffer OUT: buffer to write to
int num IN: size of target buffer
FAT_FILE* file IN: Handle of open file
bool return OUT: character if successful, EOF if not

  Written by MightyMax
  Modified by Chishm - 2005-11-17
	* Added check for unix style text files
	* Removed seek when no newline is found, since it isn't necessary
-------------------------------------------------------------------*/
char *FAT_fgets(char *tgtBuffer, int num, FAT_FILE* file) ;

#ifdef CAN_WRITE_TO_DISC
/*-----------------------------------------------------------------
FAT_fputs (const char *string, FAT_FILE* file)
Writes string to file, excluding end of string character
const char *string IN: string to write
FAT_FILE* file IN: Handle of open file
bool return OUT: number of characters written if successful,
	EOF if not

  Written by MightyMax
  Modified by Chishm - 2005-11-17
	* Uses FAT_FILE instead of int
	* writtenBytes is now u32 instead of int
-------------------------------------------------------------------*/
int FAT_fputs (const char *string, FAT_FILE* file);
#endif

//------------------------------------------------------------------
#ifdef __cplusplus
}	   // extern "C"
#endif
//------------------------------------------------------------------

#endif	// ifndef _GBA_NDS_FAT