/////////////////////////////////////////////////////////////////////////
// $Id: vvfat.h,v 1.5 2011-01-01 19:14:25 vruppert Exp $
/////////////////////////////////////////////////////////////////////////
//
//  Copyright (C) 2010  The Bochs Project
//
//  This library is free software; you can redistribute it and/or
//  modify it under the terms of the GNU Lesser General Public
//  License as published by the Free Software Foundation; either
//  version 2.1 of the License, or (at your option) any later version.
//
//  This library 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
//  Lesser General Public License for more details.
//
//  You should have received a copy of the GNU Lesser General Public
//  License along with this library; if not, write to the Free Software
//  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 USA
//
/////////////////////////////////////////////////////////////////////////

#ifndef BX_VVFAT_H
#define BX_VVFAT_H

typedef struct array_t {
  char *pointer;
  unsigned int size, next, item_size;
} array_t;

typedef struct {
  Bit8u head;
  Bit8u sector;
  Bit8u cylinder;
} mbr_chs_t;

#if defined(_MSC_VER) && (_MSC_VER<1300)
#pragma pack(push, 1)
#elif defined(__MWERKS__) && defined(macintosh)
#pragma options align=packed
#endif

typedef
#if defined(_MSC_VER) && (_MSC_VER>=1300)
  __declspec(align(1))
#endif
  struct direntry_t {
    Bit8u name[8];
    Bit8u extension[3];
    Bit8u attributes;
    Bit8u reserved[2];
    Bit16u ctime;
    Bit16u cdate;
    Bit16u adate;
    Bit16u begin_hi;
    Bit16u mtime;
    Bit16u mdate;
    Bit16u begin;
    Bit32u size;
}
#if !defined(_MSC_VER)
    GCC_ATTRIBUTE((packed))
#endif
direntry_t;

#if defined(_MSC_VER) && (_MSC_VER<1300)
#pragma pack(pop)
#elif defined(__MWERKS__) && defined(macintosh)
#pragma options align=reset
#endif

// this structure are used to transparently access the files

enum {
  MODE_UNDEFINED = 0, MODE_NORMAL = 1, MODE_MODIFIED = 2,
  MODE_DIRECTORY = 4, MODE_FAKED = 8,
  MODE_DELETED = 16, MODE_RENAMED = 32
};

typedef struct mapping_t {
  // begin is the first cluster, end is the last+1
  Bit32u begin, end;
  // as s->directory is growable, no pointer may be used here
  unsigned int dir_index;
  // the clusters of a file may be in any order; this points to the first
  int first_mapping_index;
  union {
    /* offset is
     * - the offset in the file (in clusters) for a file, or
     * - the next cluster of the directory for a directory, and
     * - the address of the buffer for a faked entry
     */
    struct {
      Bit32u offset;
    } file;
    struct {
      int parent_mapping_index;
      int first_dir_index;
    } dir;
  } info;
  // path contains the full path, i.e. it always starts with s->path
  char *path;

  Bit8u mode;

  int read_only;
} mapping_t;

class vvfat_image_t : public device_image_t
{
  public:
    vvfat_image_t(const char* redolog_name);
    virtual ~vvfat_image_t();

    int open(const char* dirname);
    void close();
    Bit64s lseek(Bit64s offset, int whence);
    ssize_t read(void* buf, size_t count);
    ssize_t write(const void* buf, size_t count);
    Bit32u get_capabilities();

  private:
    bx_bool sector2CHS(Bit32u spos, mbr_chs_t *chs);
    void init_mbr();
    direntry_t* create_long_filename(const char* filename);
    void fat_set(unsigned int cluster, Bit32u value);
    void init_fat();
    direntry_t* create_short_and_long_name(unsigned int directory_start,
      const char* filename, int is_dot);
    int read_directory(int mapping_index);
    Bit32u sector2cluster(off_t sector_num);
    int init_directories(const char* dirname);
    void close_current_file(void);
    int open_file(mapping_t* mapping);
    int find_mapping_for_cluster_aux(int cluster_num, int index1, int index2);
    mapping_t* find_mapping_for_cluster(int cluster_num);
    int read_cluster(int cluster_num);
    bx_bool read_sector_from_file(const char *path, Bit8u *buffer, Bit32u sector);

    Bit8u  *first_sectors;
    Bit32u offset_to_bootsector;
    Bit32u offset_to_fat;
    Bit32u offset_to_root_dir;
    Bit32u offset_to_data;

    Bit16u cluster_size;
    Bit8u  sectors_per_cluster;
    Bit32u sectors_per_fat;
    Bit32u sector_count;
    Bit32u cluster_count; // total number of clusters of this partition
    Bit32u max_fat_value;
    Bit32u first_cluster_of_root_dir;
    Bit16u root_entries;
    Bit16u reserved_sectors;

    Bit8u  fat_type;
    array_t fat, directory, mapping;

    int current_fd;
    mapping_t* current_mapping;
    Bit8u  *cluster; // points to current cluster
    Bit8u  *cluster_buffer; // points to a buffer to hold temp data
    Bit16u current_cluster;

    const char *path;
    Bit32u sector_num;

    bx_bool use_mbr_file;
    bx_bool use_boot_file;

    redolog_t *redolog;       // Redolog instance
    char      *redolog_name;  // Redolog name
    char      *redolog_temp;  // Redolog temporary file name
};

#endif