/*
 * COPYRIGHT:       See COPYING in the top level directory
 * PROJECT:         File Management IFS Utility functions
 * FILE:            reactos/dll/win32/fmifs/init.c
 * PURPOSE:         Initialisation
 *
 * PROGRAMMERS:     Emanuele Aliberti
 *                  Hervé Poussineau (hpoussin@reactos.org)
 */

#include "precomp.h"

#include <winreg.h>

#define NTOS_MODE_USER
#include <ndk/cmfuncs.h>
#include <ndk/obfuncs.h>

static BOOLEAN FmIfsInitialized = FALSE;
LIST_ENTRY ProviderListHead;

PIFS_PROVIDER
GetProvider(
    IN PWCHAR FileSystem)
{
    PLIST_ENTRY ListEntry;
    PIFS_PROVIDER Provider;

    ListEntry = ProviderListHead.Flink;
    while (ListEntry != &ProviderListHead)
    {
        Provider = CONTAINING_RECORD(ListEntry, IFS_PROVIDER, ListEntry);
        if (_wcsicmp(Provider->Name, FileSystem) == 0)
            return Provider;
        ListEntry = ListEntry->Flink;
    }

    /* Provider not found */
    return NULL;
}


static
BOOLEAN
AddProvider(
    IN PCUNICODE_STRING FileSystem,
    IN PWCHAR DllFile)
{
    PIFS_PROVIDER Provider = NULL;
    ULONG RequiredSize;
    HMODULE hMod = NULL;
    BOOLEAN ret = FALSE;

    hMod = LoadLibraryW(DllFile);
    if (!hMod)
        goto cleanup;

    RequiredSize = FIELD_OFFSET(IFS_PROVIDER, Name)
        + FileSystem->Length + sizeof(UNICODE_NULL);
    Provider = (PIFS_PROVIDER)RtlAllocateHeap(
        RtlGetProcessHeap(),
        0,
        RequiredSize);
    if (!Provider)
        goto cleanup;
    RtlZeroMemory(Provider, RequiredSize);

    /* Get function pointers */
    Provider->ChkdskEx = (CHKDSKEX)GetProcAddress(hMod, "ChkdskEx");
    //Provider->Extend = (EXTEND)GetProcAddress(hMod, "Extend");
    Provider->FormatEx = (FORMATEX)GetProcAddress(hMod, "FormatEx");

    RtlCopyMemory(Provider->Name, FileSystem->Buffer, FileSystem->Length);

    InsertTailList(&ProviderListHead, &Provider->ListEntry);
    ret = TRUE;

cleanup:
    if (!ret)
    {
        if (hMod)
            FreeLibrary(hMod);
        if (Provider)
            RtlFreeHeap(RtlGetProcessHeap(), 0, Provider);
    }
    return ret;
}

static
BOOLEAN
InitializeFmIfsOnce(VOID)
{
    OBJECT_ATTRIBUTES ObjectAttributes;
    UNICODE_STRING RegistryPath
        = RTL_CONSTANT_STRING(L"\\REGISTRY\\Machine\\SOFTWARE\\ReactOS\\ReactOS\\CurrentVersion\\IFS");
    HANDLE hKey = NULL;
    PKEY_VALUE_FULL_INFORMATION Buffer;
    ULONG BufferSize = sizeof(KEY_VALUE_FULL_INFORMATION) + MAX_PATH;
    ULONG RequiredSize;
    ULONG i = 0;
    UNICODE_STRING Name;
    UNICODE_STRING Data;
    NTSTATUS Status;

    InitializeListHead(&ProviderListHead);

    /* Read IFS providers from HKLM\SOFTWARE\ReactOS\ReactOS\CurrentVersion\IFS */
    InitializeObjectAttributes(&ObjectAttributes, &RegistryPath, 0, NULL, NULL);
    Status = NtOpenKey(&hKey, KEY_QUERY_VALUE, &ObjectAttributes);
    if (Status == STATUS_OBJECT_NAME_NOT_FOUND)
        return TRUE;
    else if (!NT_SUCCESS(Status))
        return FALSE;

    Buffer = (PKEY_VALUE_FULL_INFORMATION)RtlAllocateHeap(
        RtlGetProcessHeap(),
        0,
        BufferSize);
    if (!Buffer)
    {
        NtClose(hKey);
        return FALSE;
    }

    while (TRUE)
    {
        Status = NtEnumerateValueKey(
            hKey,
            i++,
            KeyValueFullInformation,
            Buffer,
            BufferSize,
            &RequiredSize);
        if (Status == STATUS_BUFFER_OVERFLOW)
            continue;
        else if (!NT_SUCCESS(Status))
            break;
        else if (Buffer->Type != REG_SZ)
            continue;

        Name.Length = Name.MaximumLength = Buffer->NameLength;
        Name.Buffer = Buffer->Name;
        Data.Length = Data.MaximumLength = Buffer->DataLength;
        Data.Buffer = (PWCHAR)((ULONG_PTR)Buffer + Buffer->DataOffset);
        if (Data.Length > sizeof(WCHAR) && Data.Buffer[Data.Length / sizeof(WCHAR) - 1] == UNICODE_NULL)
            Data.Length -= sizeof(WCHAR);

        AddProvider(&Name, Data.Buffer);
    }

    NtClose(hKey);
    RtlFreeHeap(RtlGetProcessHeap(), 0, Buffer);
    return TRUE;
}

/* FMIFS.8 */
BOOLEAN
NTAPI
InitializeFmIfs(
    IN PVOID hinstDll,
    IN DWORD dwReason,
    IN PVOID reserved)
{
    switch (dwReason)
    {
        case DLL_PROCESS_ATTACH:
            if (FmIfsInitialized == FALSE)
            {
                if (InitializeFmIfsOnce() == FALSE)
                    return FALSE;

                FmIfsInitialized = TRUE;
            }
            break;

        case DLL_THREAD_ATTACH:
            break;

        case DLL_THREAD_DETACH:
            break;

        case DLL_PROCESS_DETACH:
            break;
    }

    return TRUE;
}

/* EOF */