#pragma once

//
//  Might be a good idea to have this as a shared
//  header with FS Recognizer.
//
//
// Conversion types and macros taken from internal ntifs headers
//
typedef union _UCHAR1
{
    UCHAR Uchar[1];
    UCHAR ForceAlignment;
} UCHAR1, *PUCHAR1;

typedef union _UCHAR2
{
    UCHAR Uchar[2];
    USHORT ForceAlignment;
} UCHAR2, *PUCHAR2;

typedef union _UCHAR4
{
    UCHAR Uchar[4];
    ULONG ForceAlignment;
} UCHAR4, *PUCHAR4;

#define CopyUchar1(Dst,Src) {                          \
    *((UCHAR1 *)(Dst)) = *((UNALIGNED UCHAR1 *)(Src)); \
}

#define CopyUchar2(Dst,Src) {                          \
    *((UCHAR2 *)(Dst)) = *((UNALIGNED UCHAR2 *)(Src)); \
}

#define CopyUchar4(Dst,Src) {                          \
    *((UCHAR4 *)(Dst)) = *((UNALIGNED UCHAR4 *)(Src)); \
}

#define FatUnpackBios(Bios,Pbios) {                                         \
    CopyUchar2(&(Bios)->BytesPerSector,    &(Pbios)->BytesPerSector[0]   ); \
    CopyUchar1(&(Bios)->SectorsPerCluster, &(Pbios)->SectorsPerCluster[0]); \
    CopyUchar2(&(Bios)->ReservedSectors,   &(Pbios)->ReservedSectors[0]  ); \
    CopyUchar1(&(Bios)->Fats,              &(Pbios)->Fats[0]             ); \
    CopyUchar2(&(Bios)->RootEntries,       &(Pbios)->RootEntries[0]      ); \
    CopyUchar2(&(Bios)->Sectors,           &(Pbios)->Sectors[0]          ); \
    CopyUchar1(&(Bios)->Media,             &(Pbios)->Media[0]            ); \
    CopyUchar2(&(Bios)->SectorsPerFat,     &(Pbios)->SectorsPerFat[0]    ); \
    CopyUchar2(&(Bios)->SectorsPerTrack,   &(Pbios)->SectorsPerTrack[0]  ); \
    CopyUchar2(&(Bios)->Heads,             &(Pbios)->Heads[0]            ); \
    CopyUchar4(&(Bios)->HiddenSectors,     &(Pbios)->HiddenSectors[0]    ); \
    CopyUchar4(&(Bios)->LargeSectors,      &(Pbios)->LargeSectors[0]     ); \
    CopyUchar4(&(Bios)->LargeSectors,      &(Pbios)->LargeSectors[0]     ); \
    CopyUchar4(&(Bios)->LargeSectorsPerFat,&((PPACKED_BIOS_PARAMETER_BLOCK_EX)Pbios)->LargeSectorsPerFat[0]  ); \
    CopyUchar2(&(Bios)->ExtendedFlags,     &((PPACKED_BIOS_PARAMETER_BLOCK_EX)Pbios)->ExtendedFlags[0]       ); \
    CopyUchar2(&(Bios)->FsVersion,         &((PPACKED_BIOS_PARAMETER_BLOCK_EX)Pbios)->FsVersion[0]           ); \
    CopyUchar4(&(Bios)->RootDirFirstCluster,                                \
                                           &((PPACKED_BIOS_PARAMETER_BLOCK_EX)Pbios)->RootDirFirstCluster[0] ); \
    CopyUchar2(&(Bios)->FsInfoSector,      &((PPACKED_BIOS_PARAMETER_BLOCK_EX)Pbios)->FsInfoSector[0]        ); \
    CopyUchar2(&(Bios)->BackupBootSector,  &((PPACKED_BIOS_PARAMETER_BLOCK_EX)Pbios)->BackupBootSector[0]    ); \
}
//
//  Packed versions of the BPB and Boot Sector
//
typedef struct _PACKED_BIOS_PARAMETER_BLOCK
{
    UCHAR BytesPerSector[2];
    UCHAR SectorsPerCluster[1];
    UCHAR ReservedSectors[2];
    UCHAR Fats[1];
    UCHAR RootEntries[2];
    UCHAR Sectors[2];
    UCHAR Media[1];
    UCHAR SectorsPerFat[2];
    UCHAR SectorsPerTrack[2];
    UCHAR Heads[2];
    UCHAR HiddenSectors[4];
    UCHAR LargeSectors[4];
} PACKED_BIOS_PARAMETER_BLOCK, *PPACKED_BIOS_PARAMETER_BLOCK;
//  sizeof = 0x019

typedef struct _PACKED_BIOS_PARAMETER_BLOCK_EX
{
    PACKED_BIOS_PARAMETER_BLOCK Block;
    UCHAR LargeSectorsPerFat[4];
    UCHAR ExtendedFlags[2];
    UCHAR FsVersion[2];
    UCHAR RootDirFirstCluster[4];
    UCHAR FsInfoSector[2];
    UCHAR BackupBootSector[2];
    UCHAR Reserved[12];
} PACKED_BIOS_PARAMETER_BLOCK_EX, *PPACKED_BIOS_PARAMETER_BLOCK_EX;
//  sizeof = 0x035 53

//
//  Unpacked version of the BPB
//
typedef struct BIOS_PARAMETER_BLOCK
{
    USHORT BytesPerSector;
    UCHAR SectorsPerCluster;
    USHORT ReservedSectors;
    UCHAR Fats;
    USHORT RootEntries;
    USHORT Sectors;
    UCHAR Media;
    USHORT SectorsPerFat;
    USHORT SectorsPerTrack;
    USHORT Heads;
    ULONG HiddenSectors;
    ULONG LargeSectors;
    ULONG LargeSectorsPerFat;
    union
    {
        USHORT ExtendedFlags;
        struct
        {
            ULONG ActiveFat:4;
            ULONG Reserved0:3;
            ULONG MirrorDisabled:1;
            ULONG Reserved1:8;
        };
    };
    USHORT FsVersion;
    ULONG RootDirFirstCluster;
    USHORT FsInfoSector;
    USHORT BackupBootSector;
} BIOS_PARAMETER_BLOCK, *PBIOS_PARAMETER_BLOCK;

#define FatValidBytesPerSector(xBytes) \
    (!((xBytes) & ((xBytes)-1)) && (xBytes)>=0x80 && (xBytes)<=0x1000)

#define FatValidSectorsPerCluster(xSectors) \
    (!((xSectors) & ((xSectors)-1)) && (xSectors)>0 && (xSectors)<=0x80)

typedef struct _PACKED_BOOT_SECTOR
{
    UCHAR Jump[3];
    UCHAR Oem[8];
    PACKED_BIOS_PARAMETER_BLOCK	PackedBpb;
    UCHAR PhysicalDriveNumber;
    UCHAR CurrentHead;
    UCHAR Signature;
    UCHAR Id[4];
    UCHAR VolumeLabel[11];
    UCHAR SystemId[8];
} PACKED_BOOT_SECTOR, *PPACKED_BOOT_SECTOR;
//  sizeof = 0x03E

typedef struct _PACKED_BOOT_SECTOR_EX
{
    UCHAR Jump[3];
    UCHAR Oem[8];
    PACKED_BIOS_PARAMETER_BLOCK_EX PackedBpb;
    UCHAR PhysicalDriveNumber;
    UCHAR CurrentHead;
    UCHAR Signature;
    UCHAR Id[4];
    UCHAR VolumeLabel[11];
    UCHAR SystemId[8];
} PACKED_BOOT_SECTOR_EX, *PPACKED_BOOT_SECTOR_EX;
//  sizeof = 0x060

#define FatBootSectorJumpValid(xMagic) \
    ((xMagic)[0] == 0xe9 || (xMagic)[0] == 0xeb || (xMagic)[0] == 0x49)

typedef struct _FSINFO_SECTOR
{
    ULONG SectorBeginSignature;
    UCHAR Reserved[480];
    ULONG FsInfoSignature;
    ULONG FreeClusterCount;
    ULONG NextFreeCluster;
    UCHAR Reserved0[12];
    ULONG SectorEndSignature;
} FSINFO_SECTOR, *PFSINFO_SECTOR;
//  sizeof = 0x200
#define FSINFO_SECTOR_BEGIN_SIGNATURE   0x41615252
#define FSINFO_SECTOR_END_SIGNATURE     0xaa550000
#define FSINFO_SIGNATURE                0x61417272
//
//  Cluster Markers:
//
#define FAT_CLUSTER_AVAILABLE           0x00000000
#define FAT_CLUSTER_RESERVED            0x0ffffff0
#define FAT_CLUSTER_BAD                 0x0ffffff7
#define FAT_CLUSTER_LAST                0x0fffffff
//
//  Directory Structure:
//
typedef struct _FAT_TIME
{
    union {
        struct {
            USHORT DoubleSeconds : 5;
            USHORT Minute : 6;
            USHORT Hour : 5;
        };
        USHORT Value;
    };
} FAT_TIME, *PFAT_TIME;
//
//
//
typedef struct _FAT_DATE {
    union {
        struct {
            USHORT Day : 5;
            USHORT Month : 4;
            /* Relative to 1980 */
            USHORT Year : 7;
        };
        USHORT Value;
    };
} FAT_DATE, *PFAT_DATE;
//
//
//
typedef struct _FAT_DATETIME {
    union {
        struct {
            FAT_TIME    Time;
            FAT_DATE    Date;
        };
        ULONG Value;
    };
} FAT_DATETIME, *PFAT_DATETIME;
//
//
//
typedef struct _DIR_ENTRY
{
    UCHAR FileName[11];
    UCHAR Attributes;
    UCHAR Case;
    UCHAR CreationTimeTenMs;
    FAT_DATETIME CreationDateTime;
    FAT_DATE LastAccessDate;
    union {
        USHORT ExtendedAttributes;
        USHORT FirstClusterOfFileHi;
    };
    FAT_DATETIME LastWriteDateTime;
    USHORT FirstCluster;
    ULONG FileSize;
} DIR_ENTRY, *PDIR_ENTRY;
//  sizeof = 0x020

typedef struct _LONG_FILE_NAME_ENTRY {
    UCHAR SeqNum;
    UCHAR NameA[10];
    UCHAR Attributes;
    UCHAR Type;
    UCHAR Checksum;
    USHORT NameB[6];
    USHORT Reserved;
    USHORT NameC[2];
} LONG_FILE_NAME_ENTRY, *PLONG_FILE_NAME_ENTRY;
//  sizeof = 0x020

#define FAT_LFN_NAME_LENGTH \
    (RTL_FIELD_SIZE(LONG_FILE_NAME_ENTRY, NameA) \
        + RTL_FIELD_SIZE(LONG_FILE_NAME_ENTRY, NameB) \
        + RTL_FIELD_SIZE(LONG_FILE_NAME_ENTRY, NameC))

#define FAT_FN_DIR_ENTRY_LAST       0x40
#define FAT_FN_MAX_DIR_ENTIES       0x14

#define FAT_BYTES_PER_DIRENT        0x20
#define FAT_BYTES_PER_DIRENT_LOG    0x05
#define FAT_DIRENT_NEVER_USED       0x00
#define FAT_DIRENT_REALLY_0E5       0x05
#define FAT_DIRENT_DIRECTORY_ALIAS  0x2e
#define FAT_DIRENT_DELETED          0xe5

#define FAT_CASE_LOWER_BASE	        0x08
#define FAT_CASE_LOWER_EXT 	        0x10

#define FAT_DIRENT_ATTR_READ_ONLY        0x01
#define FAT_DIRENT_ATTR_HIDDEN           0x02
#define FAT_DIRENT_ATTR_SYSTEM           0x04
#define FAT_DIRENT_ATTR_VOLUME_ID        0x08
#define FAT_DIRENT_ATTR_DIRECTORY        0x10
#define FAT_DIRENT_ATTR_ARCHIVE          0x20
#define FAT_DIRENT_ATTR_DEVICE           0x40
#define FAT_DIRENT_ATTR_LFN              (FAT_DIRENT_ATTR_READ_ONLY | \
                                          FAT_DIRENT_ATTR_HIDDEN |    \
                                          FAT_DIRENT_ATTR_SYSTEM |    \
                                          FAT_DIRENT_ATTR_VOLUME_ID)