// the following defines are important and should normally be given in the make file.
// To be sure that they are not forgotten, they are given here, accepting an eventual error of redefinition
#define USE_TCL_STUBS
#define UNICODE
#define _UNICODE
#define DLL_BUILD
#include <Windows.h>
#include <tchar.h>
#include "tcl.h"
int HashCmd(ClientData unused, Tcl_Interp *interp, int objc, Tcl_Obj *CONST objv[])
{
    wchar_t* fname;
    FILE * hFile;
    int hashValue;
    if (objc <= 1) {
        Tcl_WrongNumArgs(interp, 1, objv, "path");
        return TCL_ERROR;
    }
    // Get the native path as a UNICODE value from the function argument.
    fname = Tcl_FSGetNativePath(objv[1]);
    // Open the file in binary read mode
    if ( NULL == fname || NULL == (hFile = _wfopen(fname, L"rb"))) {
        Tcl_SetStringObj( Tcl_GetObjResult(interp), "Wrong file path",-1);
        return TCL_ERROR;
    }
    // ToDo:
    // do the hashing here into variable hashValue by reading from file handler hFile

    // Close the file handler
    fclose(hFile);
    // return the resulting hash value
    Tcl_SetIntObj( Tcl_GetObjResult(interp), hashValue);
    return TCL_OK;
}

// DLL entry point, not used here
BOOL __declspec(dllexport) WINAPI DllEntryPoint(HINSTANCE hInstance, DWORD seginfo, LPVOID lpCmdLine)
{
  return TRUE;
}

//  TCL setup when the DLL is loaded
int __declspec(dllexport) Hash_Init (Tcl_Interp *Interp)
{
        if (Tcl_InitStubs(Interp, "8.1", 0) == NULL)
                return TCL_ERROR;
        Tcl_CreateObjCommand(Interp, "hash", HashCmd, (ClientData)NULL, (Tcl_CmdDeleteProc *)NULL);
        Tcl_PkgProvide (Interp, "hash", "1.0");
        return TCL_OK;
}

// allow unloading of the DLL
int __declspec(dllexport) Hash_Unload (Tcl_Interp *Interp, int flags)
{
    return TCL_OK;
}