--proc/system/sstorage: Structured Storage API
--Written by Cosmin Apreutesei. Public Domain.

setfenv(1, require'winapi')
require'winapi.ole'
require'winapi.uuid'

ffi.cdef[[
/* Storage instantiation modes */
static const int STGM_DIRECT             = 0x00000000L;
static const int STGM_TRANSACTED         = 0x00010000L;
static const int STGM_SIMPLE             = 0x08000000L;

static const int STGM_READ               = 0x00000000L;
static const int STGM_WRITE              = 0x00000001L;
static const int STGM_READWRITE          = 0x00000002L;

static const int STGM_SHARE_DENY_NONE    = 0x00000040L;
static const int STGM_SHARE_DENY_READ    = 0x00000030L;
static const int STGM_SHARE_DENY_WRITE   = 0x00000020L;
static const int STGM_SHARE_EXCLUSIVE    = 0x00000010L;

static const int STGM_PRIORITY           = 0x00040000L;
static const int STGM_DELETEONRELEASE    = 0x04000000L;
static const int STGM_NOSCRATCH          = 0x00100000L;

static const int STGM_CREATE             = 0x00001000L;
static const int STGM_CONVERT            = 0x00020000L;
static const int STGM_FAILIFTHERE        = 0x00000000L;

static const int STGM_NOSNAPSHOT         = 0x00200000L;
static const int STGM_DIRECT_SWMR        = 0x00400000L;

typedef struct IPropertyStorage IPropertyStorage;
typedef struct IEnumSTATPROPSTG IEnumSTATPROPSTG;

typedef unsigned short VARTYPE;
typedef double DATE;

// Currency
typedef union tagCY {
    struct {
        unsigned long Lo;
        long      Hi;
    };
    LONGLONG int64;
} CY;

/* 0 == FALSE, -1 == TRUE */
typedef short VARIANT_BOOL;
typedef VARIANT_BOOL _VARIANT_BOOL;

typedef LONG SCODE;
typedef SCODE *PSCODE;

typedef struct tagCLIPDATA {
	ULONG cbSize;
	long ulClipFmt;
	BYTE *pClipData;
} CLIPDATA;

typedef struct tagBLOB
    {
    ULONG cbSize;
    BYTE *pBlobData;
    }   BLOB;

typedef struct tagBLOB *LPBLOB;

typedef struct tagBSTRBLOB
    {
    ULONG cbSize;
    BYTE *pData;
    }   BSTRBLOB;

typedef struct tagBSTRBLOB *LPBSTRBLOB;

typedef struct tagSAFEARRAYBOUND
{
    ULONG cElements;
    LONG lLbound;
} 	SAFEARRAYBOUND;

typedef struct tagSAFEARRAYBOUND *LPSAFEARRAYBOUND;

typedef struct tagSAFEARRAY
    {
    USHORT cDims;
    USHORT fFeatures;
    ULONG cbElements;
    ULONG cLocks;
    PVOID pvData;
    SAFEARRAYBOUND rgsabound[ 1 ];
    } 	SAFEARRAY;

typedef SAFEARRAY *LPSAFEARRAY;

typedef struct tagDEC {
    USHORT wReserved;
    union {
        struct {
            BYTE scale;
            BYTE sign;
        };
        USHORT signscale;
    };
    ULONG Hi32;
    union {
        struct {
            ULONG Lo32;
            ULONG Mid32;
        } ;
        ULONGLONG Lo64;
    } ;
} DECIMAL;
typedef DECIMAL *LPDECIMAL;

enum VARENUM {
    VT_EMPTY= 0,
    VT_NULL = 1,
    VT_I2   = 2,
    VT_I4   = 3,
    VT_R4   = 4,
    VT_R8   = 5,
    VT_CY   = 6,
    VT_DATE = 7,
    VT_BSTR = 8,
    VT_DISPATCH = 9,
    VT_ERROR    = 10,
    VT_BOOL = 11,
    VT_VARIANT  = 12,
    VT_UNKNOWN  = 13,
    VT_DECIMAL  = 14,
    VT_I1   = 16,
    VT_UI1  = 17,
    VT_UI2  = 18,
    VT_UI4  = 19,
    VT_I8   = 20,
    VT_UI8  = 21,
    VT_INT  = 22,
    VT_UINT = 23,
    VT_VOID = 24,
    VT_HRESULT  = 25,
    VT_PTR  = 26,
    VT_SAFEARRAY    = 27,
    VT_CARRAY   = 28,
    VT_USERDEFINED  = 29,
    VT_LPSTR    = 30,
    VT_LPWSTR   = 31,
    VT_RECORD   = 36,
    VT_INT_PTR  = 37,
    VT_UINT_PTR = 38,
    VT_FILETIME = 64,
    VT_BLOB = 65,
    VT_STREAM   = 66,
    VT_STORAGE  = 67,
    VT_STREAMED_OBJECT  = 68,
    VT_STORED_OBJECT    = 69,
    VT_BLOB_OBJECT  = 70,
    VT_CF   = 71,
    VT_CLSID    = 72,
    VT_VERSIONED_STREAM = 73,
    VT_BSTR_BLOB    = 0xfff,
    VT_VECTOR   = 0x1000,
    VT_ARRAY    = 0x2000,
    VT_BYREF    = 0x4000,
    VT_RESERVED = 0x8000,
    VT_ILLEGAL  = 0xffff,
    VT_ILLEGALMASKED    = 0xfff,
    VT_TYPEMASK = 0xfff
};

typedef struct tagPROPSPEC
    {
    ULONG ulKind;
    union
        {
        PROPID propid;
        LPOLESTR lpwstr;
         /* Empty union arm */
        }   ;
    }   PROPSPEC;

typedef struct tagSTATPROPSTG
    {
    LPOLESTR lpwstrName;
    PROPID propid;
    VARTYPE vt;
    }   STATPROPSTG;

typedef struct tagVersionedStream
    {
    GUID guidVersion;
    IStream *pStream;
    }   VERSIONEDSTREAM;

typedef struct tagVersionedStream *LPVERSIONEDSTREAM;

typedef struct tagPROPVARIANT PROPVARIANT;

typedef struct tagCAC
    {
    ULONG cElems;
    CHAR *pElems;
    }   CAC;

typedef struct tagCAUB
    {
    ULONG cElems;
    UCHAR *pElems;
    }   CAUB;

typedef struct tagCAI
    {
    ULONG cElems;
    SHORT *pElems;
    }   CAI;

typedef struct tagCAUI
    {
    ULONG cElems;
    USHORT *pElems;
    }   CAUI;

typedef struct tagCAL
    {
    ULONG cElems;
    LONG *pElems;
    }   CAL;

typedef struct tagCAUL
    {
    ULONG cElems;
    ULONG *pElems;
    }   CAUL;

typedef struct tagCAFLT
    {
    ULONG cElems;
    FLOAT *pElems;
    }   CAFLT;

typedef struct tagCADBL
    {
    ULONG cElems;
    DOUBLE *pElems;
    }   CADBL;

typedef struct tagCACY
    {
    ULONG cElems;
    CY *pElems;
    }   CACY;

typedef struct tagCADATE
    {
    ULONG cElems;
    DATE *pElems;
    }   CADATE;

typedef struct tagCABSTR
    {
    ULONG cElems;
    BSTR *pElems;
    }   CABSTR;

typedef struct tagCABSTRBLOB
    {
    ULONG cElems;
    BSTRBLOB *pElems;
    }   CABSTRBLOB;

typedef struct tagCABOOL
    {
    ULONG cElems;
    VARIANT_BOOL *pElems;
    }   CABOOL;

typedef struct tagCASCODE
    {
    ULONG cElems;
    SCODE *pElems;
    }   CASCODE;

typedef struct tagCAPROPVARIANT
    {
    ULONG cElems;
    PROPVARIANT *pElems;
    }   CAPROPVARIANT;

typedef struct tagCAH
    {
    ULONG cElems;
    LARGE_INTEGER *pElems;
    }   CAH;

typedef struct tagCAUH
    {
    ULONG cElems;
    ULARGE_INTEGER *pElems;
    }   CAUH;

typedef struct tagCALPSTR
    {
    ULONG cElems;
    LPSTR *pElems;
    }   CALPSTR;

typedef struct tagCALPWSTR
    {
    ULONG cElems;
    LPWSTR *pElems;
    }   CALPWSTR;

typedef struct tagCAFILETIME
    {
    ULONG cElems;
    FILETIME *pElems;
    }   CAFILETIME;

typedef struct tagCACLIPDATA
    {
    ULONG cElems;
    CLIPDATA *pElems;
    }   CACLIPDATA;

typedef struct tagCACLSID
    {
    ULONG cElems;
    CLSID *pElems;
    }   CACLSID;

// This is the standard C layout of the structure.
typedef WORD PROPVAR_PAD1;
typedef WORD PROPVAR_PAD2;
typedef WORD PROPVAR_PAD3;

struct tagPROPVARIANT {
  union {
struct tag_inner_PROPVARIANT
    {
    VARTYPE vt;
    PROPVAR_PAD1 wReserved1;
    PROPVAR_PAD2 wReserved2;
    PROPVAR_PAD3 wReserved3;
    union
        {
         /* Empty union arm */
        CHAR cVal;
        UCHAR bVal;
        SHORT iVal;
        USHORT uiVal;
        LONG lVal;
        ULONG ulVal;
        INT intVal;
        UINT uintVal;
        LARGE_INTEGER hVal;
        ULARGE_INTEGER uhVal;
        FLOAT fltVal;
        DOUBLE dblVal;
        VARIANT_BOOL boolVal;
        _VARIANT_BOOL boola;
        SCODE scode;
        CY cyVal;
        DATE date;
        FILETIME filetime;
        CLSID *puuid;
        CLIPDATA *pclipdata;
        BSTR bstrVal;
        BSTRBLOB bstrblobVal;
        BLOB blob;
        LPSTR pszVal;
        LPWSTR pwszVal;
        IUnknown *punkVal;
        IDispatch *pdispVal;
        IStream *pStream;
        IStorage *pStorage;
        LPVERSIONEDSTREAM pVersionedStream;
        LPSAFEARRAY parray;
        CAC cac;
        CAUB caub;
        CAI cai;
        CAUI caui;
        CAL cal;
        CAUL caul;
        CAH cah;
        CAUH cauh;
        CAFLT caflt;
        CADBL cadbl;
        CABOOL cabool;
        CASCODE cascode;
        CACY cacy;
        CADATE cadate;
        CAFILETIME cafiletime;
        CACLSID cauuid;
        CACLIPDATA caclipdata;
        CABSTR cabstr;
        CABSTRBLOB cabstrblob;
        CALPSTR calpstr;
        CALPWSTR calpwstr;
        CAPROPVARIANT capropvar;
        CHAR *pcVal;
        UCHAR *pbVal;
        SHORT *piVal;
        USHORT *puiVal;
        LONG *plVal;
        ULONG *pulVal;
        INT *pintVal;
        UINT *puintVal;
        FLOAT *pfltVal;
        DOUBLE *pdblVal;
        VARIANT_BOOL *pboolVal;
        DECIMAL *pdecVal;
        SCODE *pscode;
        CY *pcyVal;
        DATE *pdate;
        BSTR *pbstrVal;
        IUnknown **ppunkVal;
        IDispatch **ppdispVal;
        LPSAFEARRAY *pparray;
        PROPVARIANT *pvarVal;
        }   ;
    } ;
    DECIMAL decVal;
  };
};

typedef struct tagPROPVARIANT * LPPROPVARIANT;
typedef const PROPVARIANT *     REFPROPVARIANT;
]]

local PROPVARIANT = ffi.typeof("PROPVARIANT")
local PROPVARIANT_mt = {
    __tostring = function(self)
        if self.vt == ffi.C.VT_BLOB then
            return tostring(self.blob)
        elseif self.vt == ffi.C.VT_BOOL then
            return not (self.boolVal == 0);
        elseif self.vt == ffi.C.VT_CLSID then
            return tostring(ffi.cast("CLSID *", self.puuid))
        elseif self.vt == ffi.C.VT_LPWSTR then
            return mbs(self.pwszVal)
        elseif self.vt == ffi.C.VT_UI4 then
            return tonumber(self.uintVal)
        end

        return tostring(self.pcVal)
    end,
}
ffi.metatype(PROPVARIANT, PROPVARIANT_mt)

ffi.cdef[[
// Reserved global Property IDs
static const int PID_DICTIONARY  = 0;
static const int PID_CODEPAGE    = 0x1;
static const int PID_FIRST_USABLE    = 0x2;
static const int PID_FIRST_NAME_DEFAULT  = 0xfff;
static const int PID_LOCALE  = 0x80000000;
static const int PID_MODIFY_TIME = 0x80000001;
static const int PID_SECURITY    = 0x80000002;
static const int PID_BEHAVIOR    = 0x80000003;
static const int PID_ILLEGAL = 0xffffffff;

// Range which is read-only to downlevel implementations
static const int PID_MIN_READONLY    = 0x80000000;
static const int PID_MAX_READONLY    = 0xbfffffff;

// Property IDs for the DiscardableInformation Property Set
static const int PIDDI_THUMBNAIL          = 0x00000002L; // VT_BLOB

// Property IDs for the SummaryInformation Property Set
static const int PIDSI_TITLE               = 0x00000002L;  // VT_LPSTR
static const int PIDSI_SUBJECT             = 0x00000003L;  // VT_LPSTR
static const int PIDSI_AUTHOR              = 0x00000004L;  // VT_LPSTR
static const int PIDSI_KEYWORDS            = 0x00000005L;  // VT_LPSTR
static const int PIDSI_COMMENTS            = 0x00000006L;  // VT_LPSTR
static const int PIDSI_TEMPLATE            = 0x00000007L;  // VT_LPSTR
static const int PIDSI_LASTAUTHOR          = 0x00000008L;  // VT_LPSTR
static const int PIDSI_REVNUMBER           = 0x00000009L;  // VT_LPSTR
static const int PIDSI_EDITTIME            = 0x0000000aL;  // VT_FILETIME (UTC)
static const int PIDSI_LASTPRINTED         = 0x0000000bL;  // VT_FILETIME (UTC)
static const int PIDSI_CREATE_DTM          = 0x0000000cL;  // VT_FILETIME (UTC)
static const int PIDSI_LASTSAVE_DTM        = 0x0000000dL;  // VT_FILETIME (UTC)
static const int PIDSI_PAGECOUNT           = 0x0000000eL;  // VT_I4
static const int PIDSI_WORDCOUNT           = 0x0000000fL;  // VT_I4
static const int PIDSI_CHARCOUNT           = 0x00000010L;  // VT_I4
static const int PIDSI_THUMBNAIL           = 0x00000011L;  // VT_CF
static const int PIDSI_APPNAME             = 0x00000012L;  // VT_LPSTR
static const int PIDSI_DOC_SECURITY        = 0x00000013L;  // VT_I4

// Property IDs for the DocSummaryInformation Property Set
static const int PIDDSI_CATEGORY          = 0x00000002; // VT_LPSTR
static const int PIDDSI_PRESFORMAT        = 0x00000003; // VT_LPSTR
static const int PIDDSI_BYTECOUNT         = 0x00000004; // VT_I4
static const int PIDDSI_LINECOUNT         = 0x00000005; // VT_I4
static const int PIDDSI_PARCOUNT          = 0x00000006; // VT_I4
static const int PIDDSI_SLIDECOUNT        = 0x00000007; // VT_I4
static const int PIDDSI_NOTECOUNT         = 0x00000008; // VT_I4
static const int PIDDSI_HIDDENCOUNT       = 0x00000009; // VT_I4
static const int PIDDSI_MMCLIPCOUNT       = 0x0000000A; // VT_I4
static const int PIDDSI_SCALE             = 0x0000000B; // VT_BOOL
static const int PIDDSI_HEADINGPAIR       = 0x0000000C; // VT_VARIANT | VT_VECTOR
static const int PIDDSI_DOCPARTS          = 0x0000000D; // VT_LPSTR | VT_VECTOR
static const int PIDDSI_MANAGER           = 0x0000000E; // VT_LPSTR
static const int PIDDSI_COMPANY           = 0x0000000F; // VT_LPSTR
static const int PIDDSI_LINKSDIRTY        = 0x00000010; // VT_BOOL

//  FMTID_MediaFileSummaryInfo - Property IDs
static const int PIDMSI_EDITOR                   = 0x00000002L;  // VT_LPWSTR
static const int PIDMSI_SUPPLIER                 = 0x00000003L;  // VT_LPWSTR
static const int PIDMSI_SOURCE                   = 0x00000004L;  // VT_LPWSTR
static const int PIDMSI_SEQUENCE_NO              = 0x00000005L;  // VT_LPWSTR
static const int PIDMSI_PROJECT                  = 0x00000006L;  // VT_LPWSTR
static const int PIDMSI_STATUS                   = 0x00000007L;  // VT_UI4
static const int PIDMSI_OWNER                    = 0x00000008L;  // VT_LPWSTR
static const int PIDMSI_RATING                   = 0x00000009L;  // VT_LPWSTR
static const int PIDMSI_PRODUCTION               = 0x0000000AL;  // VT_FILETIME (UTC)
static const int PIDMSI_COPYRIGHT                = 0x0000000BL;  // VT_LPWSTR

static const int PRSPEC_INVALID = ( 0xffffffff );
static const int PRSPEC_LPWSTR  = ( 0 );
static const int PRSPEC_PROPID  = ( 1 );

typedef struct IEnumSTATPROPSTGVtbl
{
	HRESULT ( __stdcall *QueryInterface )(
		IEnumSTATPROPSTG * This,
		REFIID riid,
		void **ppvObject);

	ULONG ( __stdcall *AddRef )(
		IEnumSTATPROPSTG * This);

	ULONG ( __stdcall *Release )(
		IEnumSTATPROPSTG * This);

	HRESULT ( __stdcall *Next )(
		IEnumSTATPROPSTG * This,
		ULONG celt,
		STATPROPSTG *rgelt,
		ULONG *pceltFetched);

	HRESULT ( __stdcall *Skip )(
		IEnumSTATPROPSTG * This,
		ULONG celt);

	HRESULT ( __stdcall *Reset )(
		IEnumSTATPROPSTG * This);

	HRESULT ( __stdcall *Clone )(
		IEnumSTATPROPSTG * This,
		IEnumSTATPROPSTG **ppenum);

} IEnumSTATPROPSTGVtbl;

struct IEnumSTATPROPSTG
{
	const struct IEnumSTATPROPSTGVtbl *lpVtbl;
};

typedef struct tagSTATPROPSETSTG {
	FMTID fmtid;
	CLSID clsid;
	DWORD grfFlags;
	FILETIME mtime;
	FILETIME ctime;
	FILETIME atime;
	DWORD dwOSVersion;
} STATPROPSETSTG;

	typedef struct IPropertyStorageVtbl
	{

	HRESULT ( __stdcall *QueryInterface )(
		IPropertyStorage * This,
		/* [in] */ REFIID riid,
		  void **ppvObject);

	ULONG ( __stdcall *AddRef )(
		IPropertyStorage * This);

	ULONG ( __stdcall *Release )(
		IPropertyStorage * This);

	HRESULT ( __stdcall *ReadMultiple )(
		IPropertyStorage * This,
		/* [in] */ ULONG cpspec,
		/* [size_is][in] */ const PROPSPEC rgpspec[  ],
		/* [size_is][out] */ PROPVARIANT rgpropvar[  ]);

	HRESULT ( __stdcall *WriteMultiple )(
		IPropertyStorage * This,
		/* [in] */ ULONG cpspec,
		/* [size_is][in] */ const PROPSPEC rgpspec[  ],
		/* [size_is][in] */ const PROPVARIANT rgpropvar[  ],
		/* [in] */ PROPID propidNameFirst);

	HRESULT ( __stdcall *DeleteMultiple )(
		IPropertyStorage * This,
		/* [in] */ ULONG cpspec,
		/* [size_is][in] */ const PROPSPEC rgpspec[  ]);

	HRESULT ( __stdcall *ReadPropertyNames )(
		IPropertyStorage * This,
		/* [in] */ ULONG cpropid,
		/* [size_is][in] */ const PROPID rgpropid[  ],
		/* [size_is][out] */ LPOLESTR rglpwstrName[  ]);

	HRESULT ( __stdcall *WritePropertyNames )(
		IPropertyStorage * This,
		/* [in] */ ULONG cpropid,
		/* [size_is][in] */ const PROPID rgpropid[  ],
		/* [size_is][in] */ const LPOLESTR rglpwstrName[  ]);

	HRESULT ( __stdcall *DeletePropertyNames )(
		IPropertyStorage * This,
		/* [in] */ ULONG cpropid,
		/* [size_is][in] */ const PROPID rgpropid[  ]);

	HRESULT ( __stdcall *Commit )(
		IPropertyStorage * This,
		/* [in] */ DWORD grfCommitFlags);

	HRESULT ( __stdcall *Revert )(
		IPropertyStorage * This);

	HRESULT ( __stdcall *Enum )(
		IPropertyStorage * This,
		/* [out] */ IEnumSTATPROPSTG **ppenum);

	HRESULT ( __stdcall *SetTimes )(
		IPropertyStorage * This,
		/* [in] */ const FILETIME *pctime,
		/* [in] */ const FILETIME *patime,
		/* [in] */ const FILETIME *pmtime);

	HRESULT ( __stdcall *SetClass )(
		IPropertyStorage * This,
		/* [in] */ REFCLSID clsid);

	HRESULT ( __stdcall *Stat )(
		IPropertyStorage * This,
		/* [out] */ STATPROPSETSTG *pstatpsstg);

	} IPropertyStorageVtbl;

	struct IPropertyStorage
	{
	const struct IPropertyStorageVtbl *lpVtbl;
	};
]]

BLOB = types.BLOB
local BLOB_mt = {
	__tostring = function(self)
		return string.format("BLOB(%d, %s)", self.cbSize, tostring(self.pBlobData))
	end,
}
ffi.metatype('BLOB', BLOB_mt)

IID_IPropertyStorage = UuidFromString("00000138-0000-0000-C000-000000000046");
IID_IEnumSTATPROPSTG = UuidFromString("00000139-0000-0000-C000-000000000046");