#include <windows.h>
#include <winternl.h>

typedef NTSTATUS  (__stdcall *NT_OPEN_FILE)(_Out_ PHANDLE FileHandle, _In_ ACCESS_MASK DesiredAccess, IN POBJECT_ATTRIBUTES ObjectAttributes, _Out_ PIO_STATUS_BLOCK IoStatusBlock, _In_ ULONG ShareAccess, _In_ ULONG OpenOptions);
NT_OPEN_FILE NtOpenFileStruct;

// typedef VOID (__stdcall *RTL_INIT_ANSI_STRING)(_Out_ PANSI_STRING DestinationString, _In_opt_ PCSZ SourceString);
// RTL_INIT_ANSI_STRING RtlInitAnsiStringStruct;

// typedef VOID (__stdcall *RTL_INIT_STRING)(_Out_ PSTRING DestinationString, _In_opt_ PCSZ SourceString);
// RTL_INIT_STRING RtlInitStringStruct;

typedef NTSTATUS (__stdcall *RTL_ANSI_STRING_TO_UNICODE_STRING)(_Inout_ PUNICODE_STRING DestinationString, _In_ PCANSI_STRING SourceString, _In_ BOOLEAN AllocateDestinationString);
RTL_ANSI_STRING_TO_UNICODE_STRING RtlAnsiStringToUnicodeStringStruct;

// typedef BOOLEAN (__stdcall *RTL_DOS_PATH_NAME_TO_RELATIVE_NT_PATH_NAME_U)(_In_ PCWSTR DosFileName, _Out_ PUNICODE_STRING NtFileName, _Out_opt_  PWSTR* FilePath, _Out_opt_ PRTL_RELATIVE_NAME RelativeName);
// RTL_DOS_PATH_NAME_TO_RELATIVE_NT_PATH_NAME_U RtlDosPathNameToRelativeNtPathName_UStruct;

typedef BOOLEAN (__stdcall *RTL_DOS_PATH_NAME_TO_NT_PATH_NAME_U)(_In_opt_z_ PCWSTR DosPathName, _Out_ PUNICODE_STRING NtPathName, _Out_opt_ PCWSTR * NtFileNamePart, _Out_opt_ PVOID DirectoryInfo);
RTL_DOS_PATH_NAME_TO_NT_PATH_NAME_U RtlDosPathNameToNtPathName_UStruct;

typedef VOID  (__stdcall *RTL_INIT_UNICODE_STRING)(_Inout_ PUNICODE_STRING DestinationString, _In_opt_ PCWSTR SourceString);
RTL_INIT_UNICODE_STRING RtlInitUnicodeStringStruct;

typedef VOID (__stdcall *RTL_FREE_UNICODE_STRING)(_Inout_ PUNICODE_STRING UnicodeString);
RTL_FREE_UNICODE_STRING RtlFreeUnicodeStringStruct;

static void local_init_ntdll(void);

static void local_init_ntdll(void)
{
    /* load the ntdll.dll */
    HMODULE hModule = LoadLibrary("ntdll.dll");

    NtOpenFileStruct = (NT_OPEN_FILE)GetProcAddress(hModule, "NtOpenFile");
    if(NtOpenFileStruct == NULL) {
        error_printf("Error: could not find the function NtOpenFile in library ntdll.dll.");
        exit(-1);
    }
    error_printf("NtOpenFile is located at 0x%p in ntdll.dll.\n", NtOpenFileStruct);

    //RtlInitAnsiStringStruct = (RTL_INIT_ANSI_STRING)GetProcAddress(hModule, "RtlInitAnsiString");
    //if(NtOpenFileStruct == NULL) {
    //    error_printf("Error: could not find the function RtlInitAnsiString in library ntdll.dll.");
    //    exit(-1);
    //}

    //RtlInitStringStruct = (RTL_INIT_ANSI_STRING)GetProcAddress(hModule, "RtlInitString");
    //if(NtOpenFileStruct == NULL) {
    //    error_printf("Error: could not find the function RtlInitString in library ntdll.dll.");
    //    exit(-1);
    //}

    RtlAnsiStringToUnicodeStringStruct = (RTL_ANSI_STRING_TO_UNICODE_STRING)GetProcAddress(hModule, "RtlAnsiStringToUnicodeString");
    if(RtlAnsiStringToUnicodeStringStruct == NULL) {
        error_printf("Error: could not find the function RtlAnsiStringToUnicodeString in library ntdll.dll.");
        exit(-1);
    }

    // RtlDosPathNameToRelativeNtPathName_UStruct = (RTL_DOS_PATH_NAME_TO_RELATIVE_NT_PATH_NAME_U)GetProcAddress(hModule, "RtlDosPathNameToRelativeNtPathName_U");
    // if(RtlDosPathNameToRelativeNtPathName_UStruct == NULL) {
    //     error_printf("Error: could not find the function RtlDosPathNameToRelativeNtPathName in library ntdll.dll.");
    //     exit(-1);
    // }

    RtlDosPathNameToNtPathName_UStruct = (RTL_DOS_PATH_NAME_TO_NT_PATH_NAME_U)GetProcAddress(hModule, "RtlDosPathNameToNtPathName_U");
    if(RtlDosPathNameToNtPathName_UStruct == NULL) {
        error_printf("Error: could not find the function RtlDosPathNameToNtPathName in library ntdll.dll.");
        exit(-1);
    }

    RtlInitUnicodeStringStruct = (RTL_INIT_UNICODE_STRING)GetProcAddress(hModule, "RtlInitUnicodeString");
    if(RtlInitUnicodeStringStruct == NULL) {
        error_printf("Error: could not find the function RtlInitUnicodeString in library ntdll.dll.");
        exit(-1);
    }

    RtlFreeUnicodeStringStruct = (RTL_FREE_UNICODE_STRING)GetProcAddress(hModule, "RtlFreeUnicodeString");
    if(RtlFreeUnicodeStringStruct == NULL) {
        error_printf("Error: could not find the function RtlFreeUnicodeString in library ntdll.dll.");
        exit(-1);
    }

}

static HANDLE local_open_internal(FsContext *fs_ctx, const char* relative)
{
    LocalData *data = fs_ctx->private;

    error_printf("Try to open %s\n", relative);
	if (relative[0] == '.' && relative[1] == '\0') {
		return data->mount_handle;
	}

    /* create the string in the right format */
    //STRING filename;
    //ANSI_STRING filename_ANSI;
    UNICODE_STRING filename_UNICODE;

    //RtlInitStringStruct(&filename, ctx->fs_root);

    wchar_t filename_WIDECHAR[4096];

    MultiByteToWideChar(CP_ACP, 0, relative, -1, filename_WIDECHAR, sizeof(filename_WIDECHAR));
    RtlInitUnicodeStringStruct(&filename_UNICODE, filename_WIDECHAR);

    /* initialize OBJECT_ATTRIBUTES */
    OBJECT_ATTRIBUTES obja;
    InitializeObjectAttributes(&obja, &filename_UNICODE, OBJ_CASE_INSENSITIVE, data->mount_handle, NULL);
 
    /* call NtOpenFile */
    HANDLE file = NULL;
    ULONG shareAccess = FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE; //0;
    ULONG openOptions = 0; //FILE_NON_DIRECTORY_FILE; //FILE_DIRECTORY_FILE;
    IO_STATUS_BLOCK statusBlock;
    NTSTATUS stat = NtOpenFileStruct(&file, GENERIC_READ | FILE_READ_ATTRIBUTES, &obja, &statusBlock, shareAccess, openOptions);
    if(NT_SUCCESS(stat)) {
        error_printf("File successfully opened.\n");
    }
    else {
        error_printf("File could not be opened: %lx.\n", stat);
    }

    RtlFreeUnicodeStringStruct(&filename_UNICODE);

    return file;
}


static int local_init(FsContext *ctx)
{
#ifdef FS_IOC_GETVERSION
    struct statfs stbuf;
#endif
    LocalData *data = g_malloc(sizeof(*data));

    local_init_ntdll();

    //Main info sources: http://resources.infosecinstitute.com/calling-ntdll-functions-directly/ & https://googleprojectzero.blogspot.de/2016/02/the-definitive-guide-on-win32-to-nt.html
    error_printf("Try to open %s\n", ctx->fs_root);



    /* create the string in the right format */
    //STRING filename;
    //ANSI_STRING filename_ANSI;
    UNICODE_STRING filename_UNICODE;

    //RtlInitStringStruct(&filename, ctx->fs_root);

    wchar_t filename_WIDECHAR[4096];

    MultiByteToWideChar(CP_ACP, 0, ctx->fs_root, -1, filename_WIDECHAR, sizeof(filename_WIDECHAR));
    RtlDosPathNameToNtPathName_UStruct(filename_WIDECHAR, &filename_UNICODE, NULL, NULL);

    /* initialize OBJECT_ATTRIBUTES */
    OBJECT_ATTRIBUTES obja;
    InitializeObjectAttributes(&obja, &filename_UNICODE, OBJ_CASE_INSENSITIVE, NULL, NULL);
 
    /* call NtOpenFile */
    HANDLE file = NULL;
    ULONG shareAccess = 0;
    ULONG openOptions = FILE_DIRECTORY_FILE;
    IO_STATUS_BLOCK statusBlock;
    NTSTATUS stat = NtOpenFileStruct(&file, GENERIC_READ | FILE_READ_ATTRIBUTES, &obja, &statusBlock, shareAccess, openOptions);
    if(NT_SUCCESS(stat)) {
        error_printf("File successfully opened.\n");
    }
    else {
        error_printf("File could not be opened: %lx.\n", stat);
        goto err;
    }

    RtlFreeUnicodeStringStruct(&filename_UNICODE);

	
	// local_open_internal(file, "blah");
	// local_open_internal(file, "blub.txt");
	

    data->mount_handle = file;

    ctx->xops = 0;
    ctx->export_flags |= V9FS_PATHNAME_FSCONTEXT;

    ctx->private = data;
    return 0;

err:
    g_free(data);
    return -1;
}