/*
 * Copyright (c) 2006-2007 by Roland Riegel <feedback@roland-riegel.de>
 *
 * This file is free software; you can redistribute it and/or modify
 * it under the terms of either the GNU General Public License version 2
 * or the GNU Lesser General Public License version 2.1, both as
 * published by the Free Software Foundation.
 */

#ifndef FAT16_H
#define FAT16_H

#include "fat16_config.h"

#include <stdint.h>

/**
 * \addtogroup fat16
 *
 * @{
 */
/**
 * \file
 * FAT16 header (license: GPLv2 or LGPLv2.1)
 *
 * \author Roland Riegel
 */

/**
 * \addtogroup fat16_file
 * @{
 */

/** The file is read-only. */
#define FAT16_ATTRIB_READONLY (1 << 0)
/** The file is hidden. */
#define FAT16_ATTRIB_HIDDEN (1 << 1)
/** The file is a system file. */
#define FAT16_ATTRIB_SYSTEM (1 << 2)
/** The file is empty and has the volume label as its name. */
#define FAT16_ATTRIB_VOLUME (1 << 3)
/** The file is a directory. */
#define FAT16_ATTRIB_DIR (1 << 4)
/** The file has to be archived. */
#define FAT16_ATTRIB_ARCHIVE (1 << 5)

/** The given offset is relative to the beginning of the file. */
#define FAT16_SEEK_SET 0
/** The given offset is relative to the current read/write position. */
#define FAT16_SEEK_CUR 1
/** The given offset is relative to the end of the file. */
#define FAT16_SEEK_END 2

/**
 * @}
 */

struct partition_struct;
struct fat16_fs_struct;
struct fat16_file_struct;
struct fat16_dir_struct;

/**
 * \ingroup fat16_file
 * Describes a directory entry.
 */
struct fat16_dir_entry_struct
{
    /** The file's name, truncated to 13 characters. */
    char long_name[13]; // 8.3+1 null
    /** The file's attributes. Mask of the FAT16_ATTRIB_* constants. */
    uint8_t attributes;
#if FAT16_DATETIME_SUPPORT
    /** Compressed representation of modification time. */
    uint16_t modification_time;
    /** Compressed representation of modification date. */
    uint16_t modification_date;
#endif
    /** The cluster in which the file's first byte resides. */
    uint16_t cluster;
    /** The file's size. */
    uint32_t file_size;
    /** The total disk offset of this directory entry. */
    uint32_t entry_offset;
};

struct fat16_fs_struct* fat16_open(struct partition_struct* partition);
void fat16_close(struct fat16_fs_struct* fs);

struct fat16_file_struct* fat16_open_file(struct fat16_fs_struct* fs, const struct fat16_dir_entry_struct* dir_entry);
void fat16_close_file(struct fat16_file_struct* fd);
int16_t fat16_read_file(struct fat16_file_struct* fd, uint8_t* buffer, uint16_t buffer_len);
int16_t fat16_write_file(struct fat16_file_struct* fd, const uint8_t* buffer, uint16_t buffer_len);
uint8_t fat16_seek_file(struct fat16_file_struct* fd, int32_t* offset, uint8_t whence);
uint8_t fat16_resize_file(struct fat16_file_struct* fd, uint32_t size);

struct fat16_dir_struct* fat16_open_dir(struct fat16_fs_struct* fs, const struct fat16_dir_entry_struct* dir_entry);
void fat16_close_dir(struct fat16_dir_struct* dd);
uint8_t fat16_read_dir(struct fat16_dir_struct* dd, struct fat16_dir_entry_struct* dir_entry);
uint8_t fat16_reset_dir(struct fat16_dir_struct* dd);

uint8_t fat16_create_file(struct fat16_dir_struct* parent, const char* file, struct fat16_dir_entry_struct* dir_entry);
uint8_t fat16_delete_file(struct fat16_fs_struct* fs, struct fat16_dir_entry_struct* dir_entry);
uint8_t fat16_create_dir(struct fat16_dir_struct* parent, const char* dir, struct fat16_dir_entry_struct* dir_entry);
#define fat16_delete_dir fat16_delete_file

void fat16_get_file_modification_date(const struct fat16_dir_entry_struct* dir_entry, uint16_t* year, uint8_t* month, uint8_t* day);
void fat16_get_file_modification_time(const struct fat16_dir_entry_struct* dir_entry, uint8_t* hour, uint8_t* min, uint8_t* sec);


uint8_t fat16_get_dir_entry_of_root(struct fat16_fs_struct* fs, struct fat16_dir_entry_struct* dir_entry);

uint32_t fat16_get_fs_size(const struct fat16_fs_struct* fs);
uint32_t fat16_get_fs_free(const struct fat16_fs_struct* fs);
uint8_t fat16_get_fs_free_callback(uint8_t* buffer, uint32_t offset, void* p);


struct fat16_header_struct
{
    uint32_t size;

    uint32_t fat_offset;
    uint32_t fat_size;

    uint16_t sector_size;
    uint16_t cluster_size;

    uint32_t root_dir_offset;

    uint32_t cluster_zero_offset;
};

struct fat16_fs_struct
{
    struct partition_struct* partition;
    struct fat16_header_struct header;
};

struct fat16_file_struct
{
    struct fat16_fs_struct* fs;
    struct fat16_dir_entry_struct dir_entry;
    uint32_t pos;
    uint16_t pos_cluster;
};

struct fat16_dir_struct
{
    struct fat16_fs_struct* fs;
    struct fat16_dir_entry_struct dir_entry;
    uint16_t entry_next;
};

struct fat16_read_callback_arg
{
    uint16_t entry_cur;
    uint16_t entry_num;
    uint32_t entry_offset;
    uint8_t byte_count;
};

struct fat16_usage_count_callback_arg
{
    uint16_t cluster_count;
    uint8_t buffer_size;
};


/**
 * @}
 */

#endif