/*
 * COPYRIGHT:        See COPYING in the top level directory
 * PROJECT:          ReactOS Win32k subsystem
 * PURPOSE:          Input Method Editor and Input Method Manager support
 * FILE:             win32ss/user/ntuser/ime.c
 * PROGRAMERS:       Casper S. Hornstrup (chorns@users.sourceforge.net)
 *                   Katayama Hirofumi MZ (katayama.hirofumi.mz@gmail.com)
 */

#include <win32k.h>
DBG_DEFAULT_CHANNEL(UserMisc);

#define INVALID_THREAD_ID  ((ULONG)-1)
#define INVALID_HOTKEY     ((UINT)-1)
#define MOD_KEYS           (MOD_CONTROL | MOD_SHIFT | MOD_ALT | MOD_WIN)
#define MOD_LEFT_RIGHT     (MOD_LEFT | MOD_RIGHT)

#define LANGID_CHINESE_SIMPLIFIED   MAKELANGID(LANG_CHINESE,  SUBLANG_CHINESE_SIMPLIFIED)
#define LANGID_JAPANESE             MAKELANGID(LANG_JAPANESE, SUBLANG_DEFAULT)
#define LANGID_KOREAN               MAKELANGID(LANG_KOREAN,   SUBLANG_KOREAN)
#define LANGID_CHINESE_TRADITIONAL  MAKELANGID(LANG_CHINESE,  SUBLANG_CHINESE_TRADITIONAL)
#define LANGID_NEUTRAL              MAKELANGID(LANG_NEUTRAL,  SUBLANG_NEUTRAL)

// The special virtual keys for Japanese: Used for key states.
// https://www.kthree.co.jp/kihelp/index.html?page=app/vkey&type=html
#define VK_DBE_ALPHANUMERIC 0xF0
#define VK_DBE_KATAKANA 0xF1
#define VK_DBE_HIRAGANA 0xF2
#define VK_DBE_SBCSCHAR 0xF3
#define VK_DBE_DBCSCHAR 0xF4
#define VK_DBE_ROMAN 0xF5
#define VK_DBE_NOROMAN 0xF6
#define VK_DBE_ENTERWORDREGISTERMODE 0xF7
#define VK_DBE_ENTERCONFIGMODE 0xF8
#define VK_DBE_FLUSHSTRING 0xF9
#define VK_DBE_CODEINPUT 0xFA
#define VK_DBE_NOCODEINPUT 0xFB
#define VK_DBE_DETERINESTRING 0xFC
#define VK_DBE_ENTERDLGCONVERSIONMODE 0xFD

HIMC ghIMC = NULL;
BOOL gfImeOpen = (BOOL)-1;
DWORD gdwImeConversion = (DWORD)-1;

typedef struct tagIMEHOTKEY
{
    struct tagIMEHOTKEY *pNext;
    DWORD  dwHotKeyId;
    UINT   uVirtualKey;
    UINT   uModifiers;
    HKL    hKL;
} IMEHOTKEY, *PIMEHOTKEY;

PIMEHOTKEY gpImeHotKeyList = NULL; // Win: gpImeHotKeyListHeader
LCID glcidSystem = 0; // Win: glcidSystem

// Win: GetAppImeCompatFlags
DWORD FASTCALL IntGetImeCompatFlags(PTHREADINFO pti)
{
    if (!pti)
        pti = PsGetCurrentThreadWin32Thread();

    return pti->ppi->dwImeCompatFlags;
}

// Win: GetLangIdMatchLevel
UINT FASTCALL IntGetImeHotKeyLanguageScore(HKL hKL, LANGID HotKeyLangId)
{
    LCID lcid;

    if (HotKeyLangId == LANGID_NEUTRAL || HotKeyLangId == LOWORD(hKL))
        return 3;

    _SEH2_TRY
    {
        lcid = NtCurrentTeb()->CurrentLocale;
    }
    _SEH2_EXCEPT(EXCEPTION_EXECUTE_HANDLER)
    {
        lcid = MAKELCID(LANGID_NEUTRAL, SORT_DEFAULT);
    }
    _SEH2_END;

    if (HotKeyLangId == LANGIDFROMLCID(lcid))
        return 2;

    if (glcidSystem == 0)
        ZwQueryDefaultLocale(FALSE, &glcidSystem);

    if (HotKeyLangId == LANGIDFROMLCID(glcidSystem))
        return 1;

    return 0;
}

// Win: GetActiveHKL
HKL FASTCALL IntGetActiveKeyboardLayout(VOID)
{
    PTHREADINFO pti;

    if (gpqForeground && gpqForeground->spwndActive)
    {
        pti = gpqForeground->spwndActive->head.pti;
        if (pti && pti->KeyboardLayout)
            return pti->KeyboardLayout->hkl;
    }

    return UserGetKeyboardLayout(0);
}

// Win: GetHotKeyLangID
static LANGID FASTCALL IntGetImeHotKeyLangId(DWORD dwHotKeyId)
{
#define IME_CHOTKEY 0x10
#define IME_JHOTKEY 0x30
#define IME_KHOTKEY 0x50
#define IME_THOTKEY 0x70
#define IME_XHOTKEY 0x90
    static const LANGID s_array[] =
    {
        /* 0x00 */ (WORD)-1,
        /* 0x10 */ LANGID_CHINESE_SIMPLIFIED,
        /* 0x20 */ LANGID_CHINESE_SIMPLIFIED,
        /* 0x30 */ LANGID_JAPANESE,
        /* 0x40 */ LANGID_JAPANESE,
        /* 0x50 */ LANGID_KOREAN,
        /* 0x60 */ LANGID_KOREAN,
        /* 0x70 */ LANGID_CHINESE_TRADITIONAL,
        /* 0x80 */ LANGID_CHINESE_TRADITIONAL
    };

    if (IME_CHOTKEY <= dwHotKeyId && dwHotKeyId < IME_XHOTKEY)
        return s_array[(dwHotKeyId & 0xF0) >> 4];
    return LANGID_NEUTRAL;
}

// Win: AddImeHotKey
static VOID FASTCALL IntAddImeHotKey(PIMEHOTKEY *ppList, PIMEHOTKEY pHotKey)
{
    PIMEHOTKEY pNode;

    if (!*ppList)
    {
        *ppList = pHotKey;
        return;
    }

    for (pNode = *ppList; pNode; pNode = pNode->pNext)
    {
        if (!pNode->pNext)
        {
            pNode->pNext = pHotKey;
            return;
        }
    }
}

// Win: FindImeHotKeyByID
static PIMEHOTKEY FASTCALL IntGetImeHotKeyById(PIMEHOTKEY pList, DWORD dwHotKeyId)
{
    PIMEHOTKEY pNode;
    for (pNode = pList; pNode; pNode = pNode->pNext)
    {
        if (pNode->dwHotKeyId == dwHotKeyId)
            return pNode;
    }
    return NULL;
}

// Win: FindImeHotKeyByKeyWithLang
static PIMEHOTKEY APIENTRY
IntGetImeHotKeyByKeyAndLang(PIMEHOTKEY pList, UINT uModKeys, UINT uLeftRight,
                            UINT uVirtualKey, LANGID TargetLangId)
{
    PIMEHOTKEY pNode;
    LANGID LangID;
    UINT uModifiers;

    for (pNode = pList; pNode; pNode = pNode->pNext)
    {
        if (pNode->uVirtualKey != uVirtualKey)
            continue;

        LangID = IntGetImeHotKeyLangId(pNode->dwHotKeyId);
        if (LangID != TargetLangId)
            continue;

        uModifiers = pNode->uModifiers;
        if (uModifiers & MOD_IGNORE_ALL_MODIFIER)
            return pNode;

        if ((uModifiers & MOD_KEYS) != uModKeys)
            continue;

        if ((uModifiers & uLeftRight) || (uModifiers & MOD_LEFT_RIGHT) == uLeftRight)
            return pNode;
    }

    return NULL;
}

// Win: DeleteImeHotKey
static VOID FASTCALL IntDeleteImeHotKey(PIMEHOTKEY *ppList, PIMEHOTKEY pHotKey)
{
    PIMEHOTKEY pNode;

    if (*ppList == pHotKey)
    {
        *ppList = pHotKey->pNext;
        ExFreePoolWithTag(pHotKey, USERTAG_IMEHOTKEY);
        return;
    }

    for (pNode = *ppList; pNode; pNode = pNode->pNext)
    {
        if (pNode->pNext == pHotKey)
        {
            pNode->pNext = pHotKey->pNext;
            ExFreePoolWithTag(pHotKey, USERTAG_IMEHOTKEY);
            return;
        }
    }
}

// Win: FindImeHotKeyByKey
PIMEHOTKEY
IntGetImeHotKeyByKey(PIMEHOTKEY pList, UINT uModKeys, UINT uLeftRight, UINT uVirtualKey)
{
    PIMEHOTKEY pNode, ret = NULL;
    PTHREADINFO pti = GetW32ThreadInfo();
    LANGID LangId;
    HKL hKL = IntGetActiveKeyboardLayout();
    BOOL fKorean = (PRIMARYLANGID(LOWORD(hKL)) == LANG_KOREAN);
    UINT nScore, nMaxScore = 0;

    for (pNode = pList; pNode; pNode = pNode->pNext)
    {
        if (pNode->uVirtualKey != uVirtualKey)
            continue;

        if ((pNode->uModifiers & MOD_IGNORE_ALL_MODIFIER))
        {
            ;
        }
        else if ((pNode->uModifiers & MOD_KEYS) != uModKeys)
        {
            continue;
        }
        else if ((pNode->uModifiers & uLeftRight) ||
                 (pNode->uModifiers & MOD_LEFT_RIGHT) == uLeftRight)
        {
            ;
        }
        else
        {
            continue;
        }

        LangId = IntGetImeHotKeyLangId(pNode->dwHotKeyId);
        nScore = IntGetImeHotKeyLanguageScore(hKL, LangId);
        if (nScore >= 3)
            return pNode;

        if (fKorean)
            continue;

        if (nScore == 0)
        {
            if (pNode->dwHotKeyId == IME_CHOTKEY_IME_NONIME_TOGGLE ||
                pNode->dwHotKeyId == IME_THOTKEY_IME_NONIME_TOGGLE)
            {
                if (LOWORD(pti->hklPrev) == LangId)
                    return pNode;
            }
        }

        if (nMaxScore < nScore)
        {
            nMaxScore = nScore;
            ret = pNode;
        }
    }

    return ret;
}

// Win: CheckImeHotKey
PIMEHOTKEY IntCheckImeHotKey(PUSER_MESSAGE_QUEUE MessageQueue, UINT uVirtualKey, LPARAM lParam)
{
    PIMEHOTKEY pHotKey;
    UINT uModifiers;
    BOOL bKeyUp = (lParam & 0x80000000);
    const BYTE *KeyState = MessageQueue->afKeyState;
    static UINT s_uKeyUpVKey = 0;

    if (bKeyUp)
    {
        if (s_uKeyUpVKey != uVirtualKey)
        {
            s_uKeyUpVKey = 0;
            return NULL;
        }

        s_uKeyUpVKey = 0;
    }

    uModifiers = 0;
    if (IS_KEY_DOWN(KeyState, VK_LSHIFT))   uModifiers |= (MOD_SHIFT | MOD_LEFT);
    if (IS_KEY_DOWN(KeyState, VK_RSHIFT))   uModifiers |= (MOD_SHIFT | MOD_RIGHT);
    if (IS_KEY_DOWN(KeyState, VK_LCONTROL)) uModifiers |= (MOD_CONTROL | MOD_LEFT);
    if (IS_KEY_DOWN(KeyState, VK_RCONTROL)) uModifiers |= (MOD_CONTROL | MOD_RIGHT);
    if (IS_KEY_DOWN(KeyState, VK_LMENU))    uModifiers |= (MOD_ALT | MOD_LEFT);
    if (IS_KEY_DOWN(KeyState, VK_RMENU))    uModifiers |= (MOD_ALT | MOD_RIGHT);

    pHotKey = IntGetImeHotKeyByKey(gpImeHotKeyList,
                                   (uModifiers & MOD_KEYS),
                                   (uModifiers & MOD_LEFT_RIGHT),
                                   uVirtualKey);
    if (pHotKey)
    {
        if (bKeyUp)
        {
            if (pHotKey->uModifiers & MOD_ON_KEYUP)
                return pHotKey;
        }
        else
        {
            if (pHotKey->uModifiers & MOD_ON_KEYUP)
                s_uKeyUpVKey = uVirtualKey;
            else
                return pHotKey;
        }
    }

    return NULL;
}

// Win: FreeImeHotKeys
VOID FASTCALL IntFreeImeHotKeys(VOID)
{
    PIMEHOTKEY pNode, pNext;
    for (pNode = gpImeHotKeyList; pNode; pNode = pNext)
    {
        pNext = pNode->pNext;
        ExFreePoolWithTag(pNode, USERTAG_IMEHOTKEY);
    }
    gpImeHotKeyList = NULL;
}

// Win: SetImeHotKey
static BOOL APIENTRY
IntSetImeHotKey(DWORD dwHotKeyId, UINT uModifiers, UINT uVirtualKey, HKL hKL, DWORD dwAction)
{
    PIMEHOTKEY pNode;
    LANGID LangId;

    switch (dwAction)
    {
        case SETIMEHOTKEY_DELETE:
            pNode = IntGetImeHotKeyById(gpImeHotKeyList, dwHotKeyId);
            if (!pNode)
            {
                ERR("dwHotKeyId: 0x%lX\n", dwHotKeyId);
                return FALSE;
            }

            IntDeleteImeHotKey(&gpImeHotKeyList, pNode);
            return TRUE;

        case SETIMEHOTKEY_ADD:
            if (uVirtualKey == VK_PACKET)
                return FALSE;

            LangId = IntGetImeHotKeyLangId(dwHotKeyId);
            if (LangId == LANGID_KOREAN)
                return FALSE;

            pNode = IntGetImeHotKeyByKeyAndLang(gpImeHotKeyList,
                                                (uModifiers & MOD_KEYS),
                                                (uModifiers & MOD_LEFT_RIGHT),
                                                uVirtualKey, LangId);
            if (!pNode)
                pNode = IntGetImeHotKeyById(gpImeHotKeyList, dwHotKeyId);

            if (pNode)
            {
                pNode->uModifiers = uModifiers;
                pNode->uVirtualKey = uVirtualKey;
                pNode->hKL = hKL;
                return TRUE;
            }

            pNode = ExAllocatePoolWithTag(PagedPool, sizeof(IMEHOTKEY), USERTAG_IMEHOTKEY);
            if (!pNode)
                return FALSE;

            pNode->pNext = NULL;
            pNode->dwHotKeyId = dwHotKeyId;
            pNode->uModifiers = uModifiers;
            pNode->uVirtualKey = uVirtualKey;
            pNode->hKL = hKL;
            IntAddImeHotKey(&gpImeHotKeyList, pNode);
            return TRUE;

        case SETIMEHOTKEY_DELETEALL:
            IntFreeImeHotKeys();
            return TRUE;

        default:
            return FALSE;
    }
}

BOOL NTAPI
NtUserGetImeHotKey(DWORD dwHotKeyId, LPUINT lpuModifiers, LPUINT lpuVirtualKey, LPHKL lphKL)
{
    PIMEHOTKEY pNode = NULL;

    UserEnterExclusive();

    _SEH2_TRY
    {
        ProbeForWrite(lpuModifiers, sizeof(UINT), 1);
        ProbeForWrite(lpuVirtualKey, sizeof(UINT), 1);
        if (lphKL)
            ProbeForWrite(lphKL, sizeof(HKL), 1);
    }
    _SEH2_EXCEPT(EXCEPTION_EXECUTE_HANDLER)
    {
        goto Quit;
    }
    _SEH2_END;

    pNode = IntGetImeHotKeyById(gpImeHotKeyList, dwHotKeyId);
    if (!pNode)
        goto Quit;

    _SEH2_TRY
    {
        *lpuModifiers = pNode->uModifiers;
        *lpuVirtualKey = pNode->uVirtualKey;
        if (lphKL)
            *lphKL = pNode->hKL;
    }
    _SEH2_EXCEPT(EXCEPTION_EXECUTE_HANDLER)
    {
        pNode = NULL;
    }
    _SEH2_END;

Quit:
    UserLeave();
    return !!pNode;
}

BOOL
NTAPI
NtUserSetImeHotKey(
    DWORD  dwHotKeyId,
    UINT   uModifiers,
    UINT   uVirtualKey,
    HKL    hKL,
    DWORD  dwAction)
{
    BOOL ret;
    UserEnterExclusive();
    ret = IntSetImeHotKey(dwHotKeyId, uModifiers, uVirtualKey, hKL, dwAction);
    UserLeave();
    return ret;
}

DWORD
NTAPI
NtUserCheckImeHotKey(UINT uVirtualKey, LPARAM lParam)
{
    PIMEHOTKEY pNode;
    DWORD ret = INVALID_HOTKEY;

    UserEnterExclusive();

    if (!gpqForeground || !IS_IMM_MODE())
        goto Quit;

    pNode = IntCheckImeHotKey(gpqForeground, uVirtualKey, lParam);
    if (pNode)
        ret = pNode->dwHotKeyId;

Quit:
    UserLeave();
    return ret;
}

// Win: GetTopLevelWindow
PWND FASTCALL IntGetTopLevelWindow(PWND pwnd)
{
    if (!pwnd)
        return NULL;

    while (pwnd->style & WS_CHILD)
        pwnd = pwnd->spwndParent;

    return pwnd;
}

// Win: AssociateInputContext
HIMC FASTCALL IntAssociateInputContext(PWND pWnd, PIMC pImc)
{
    HIMC hOldImc = pWnd->hImc;
    pWnd->hImc = (pImc ? UserHMGetHandle(pImc) : NULL);
    return hOldImc;
}

DWORD
NTAPI
NtUserSetThreadLayoutHandles(HKL hNewKL, HKL hOldKL)
{
    PTHREADINFO pti;
    PKL pOldKL, pNewKL;

    UserEnterExclusive();

    pti = GetW32ThreadInfo();
    pOldKL = pti->KeyboardLayout;
    if (pOldKL && pOldKL->hkl != hOldKL)
        goto Quit;

    pNewKL = UserHklToKbl(hNewKL);
    if (!pNewKL)
        goto Quit;

    if (IS_IME_HKL(hNewKL) != IS_IME_HKL(hOldKL))
        pti->hklPrev = hOldKL;

    UserAssignmentLock((PVOID*)&pti->KeyboardLayout, pNewKL);

Quit:
    UserLeave();
    return 0;
}

// Win: BuildHimcList
DWORD FASTCALL UserBuildHimcList(PTHREADINFO pti, DWORD dwCount, HIMC *phList)
{
    PIMC pIMC;
    DWORD dwRealCount = 0;

    if (pti)
    {
        for (pIMC = pti->spDefaultImc; pIMC; pIMC = pIMC->pImcNext)
        {
            if (dwRealCount < dwCount)
                phList[dwRealCount] = UserHMGetHandle(pIMC);

            ++dwRealCount;
        }
    }
    else
    {
        for (pti = GetW32ThreadInfo()->ppi->ptiList; pti; pti = pti->ptiSibling)
        {
            for (pIMC = pti->spDefaultImc; pIMC; pIMC = pIMC->pImcNext)
            {
                if (dwRealCount < dwCount)
                    phList[dwRealCount] = UserHMGetHandle(pIMC);

                ++dwRealCount;
            }
        }
    }

    return dwRealCount;
}

// Win: xxxImmProcessKey
UINT FASTCALL
IntImmProcessKey(PUSER_MESSAGE_QUEUE MessageQueue, PWND pWnd, UINT uMsg,
                 WPARAM wParam, LPARAM lParam)
{
    UINT uVirtualKey, ret = 0;
    DWORD dwHotKeyId;
    PKL pKL;
    PIMC pIMC = NULL;
    PIMEHOTKEY pImeHotKey;
    HKL hKL;
    HWND hWnd;

    ASSERT_REFS_CO(pWnd);

    switch (uMsg)
    {
        case WM_KEYDOWN:
        case WM_KEYUP:
        case WM_SYSKEYDOWN:
        case WM_SYSKEYUP:
            break;

        default:
            return 0;
    }

    hWnd = UserHMGetHandle(pWnd);
    pKL = pWnd->head.pti->KeyboardLayout;
    if (!pKL)
        return 0;

    uVirtualKey = LOBYTE(wParam);
    pImeHotKey = IntCheckImeHotKey(MessageQueue, uVirtualKey, lParam);
    if (pImeHotKey)
    {
        dwHotKeyId = pImeHotKey->dwHotKeyId;
        hKL = pImeHotKey->hKL;
    }
    else
    {
        dwHotKeyId = INVALID_HOTKEY;
        hKL = NULL;
    }

    if (IME_HOTKEY_DSWITCH_FIRST <= dwHotKeyId && dwHotKeyId <= IME_HOTKEY_DSWITCH_LAST)
    {
        if (pKL->hkl != hKL)
        {
            UserPostMessage(hWnd, WM_INPUTLANGCHANGEREQUEST,
                            ((pKL->dwFontSigs & gSystemFS) ? INPUTLANGCHANGE_SYSCHARSET : 0),
                            (LPARAM)hKL);
        }

        if (IntGetImeCompatFlags(pWnd->head.pti) & 0x800000)
            return 0;

        return IPHK_HOTKEY;
    }

    if (!IS_IMM_MODE())
        return 0;

    if (dwHotKeyId == INVALID_HOTKEY)
    {
        if (!pKL->piiex)
            return 0;

        if (pWnd->hImc)
            pIMC = UserGetObject(gHandleTable, pWnd->hImc, TYPE_INPUTCONTEXT);
        if (!pIMC)
            return 0;

        if ((lParam & 0x80000000) &&
            (pKL->piiex->ImeInfo.fdwProperty & IME_PROP_IGNORE_UPKEYS))
        {
            return 0;
        }

        switch (uVirtualKey)
        {
            case VK_DBE_CODEINPUT:
            case VK_DBE_ENTERCONFIGMODE:
            case VK_DBE_ENTERWORDREGISTERMODE:
            case VK_DBE_HIRAGANA:
            case VK_DBE_KATAKANA:
            case VK_DBE_NOCODEINPUT:
            case VK_DBE_NOROMAN:
            case VK_DBE_ROMAN:
                break;

            default:
            {
                if (uMsg == WM_SYSKEYDOWN || uMsg == WM_SYSKEYUP)
                {
                    if (uVirtualKey != VK_MENU && uVirtualKey != VK_F10)
                        return 0;
                }

                if (!(pKL->piiex->ImeInfo.fdwProperty & IME_PROP_NEED_ALTKEY))
                {
                    if (uVirtualKey == VK_MENU || (lParam & 0x20000000))
                        return 0;
                }
                break;
            }
        }
    }

    if (LOBYTE(uVirtualKey) == VK_PACKET)
        uVirtualKey = MAKELONG(wParam, GetW32ThreadInfo()->wchInjected);

    ret = co_IntImmProcessKey(hWnd, pKL->hkl, uVirtualKey, lParam, dwHotKeyId);

    if (IntGetImeCompatFlags(pWnd->head.pti) & 0x800000)
        ret &= ~IPHK_HOTKEY;

    return ret;
}

NTSTATUS
NTAPI
NtUserBuildHimcList(DWORD dwThreadId, DWORD dwCount, HIMC *phList, LPDWORD pdwCount)
{
    NTSTATUS ret = STATUS_UNSUCCESSFUL;
    DWORD dwRealCount;
    PTHREADINFO pti;

    UserEnterExclusive();

    if (!IS_IMM_MODE())
    {
        ERR("!IS_IMM_MODE()\n");
        EngSetLastError(ERROR_CALL_NOT_IMPLEMENTED);
        goto Quit;
    }

    if (dwThreadId == 0)
    {
        pti = GetW32ThreadInfo();
    }
    else if (dwThreadId == INVALID_THREAD_ID)
    {
        pti = NULL;
    }
    else
    {
        pti = IntTID2PTI(UlongToHandle(dwThreadId));
        if (!pti || !pti->rpdesk)
            goto Quit;
    }

    _SEH2_TRY
    {
        ProbeForWrite(phList, dwCount * sizeof(HIMC), 1);
        ProbeForWrite(pdwCount, sizeof(DWORD), 1);
        *pdwCount = dwRealCount = UserBuildHimcList(pti, dwCount, phList);
    }
    _SEH2_EXCEPT(EXCEPTION_EXECUTE_HANDLER)
    {
        goto Quit;
    }
    _SEH2_END;

    if (dwCount < dwRealCount)
        ret = STATUS_BUFFER_TOO_SMALL;
    else
        ret = STATUS_SUCCESS;

Quit:
    UserLeave();
    return ret;
}

// Win: SetConvMode
static VOID FASTCALL UserSetImeConversionKeyState(PTHREADINFO pti, DWORD dwConversion)
{
    HKL hKL;
    LANGID LangID;
    LPBYTE KeyState;
    BOOL bAlphaNumeric, bKatakana, bHiragana, bFullShape, bRoman, bCharCode;

    if (!pti->KeyboardLayout)
        return;

    hKL = pti->KeyboardLayout->hkl;
    LangID = LOWORD(hKL);
    KeyState = pti->MessageQueue->afKeyState;

    switch (PRIMARYLANGID(LangID))
    {
        case LANG_JAPANESE:
            bAlphaNumeric = !(dwConversion & IME_CMODE_NATIVE);
            bKatakana = !bAlphaNumeric && (dwConversion & IME_CMODE_KATAKANA);
            bHiragana = !bAlphaNumeric && !(dwConversion & IME_CMODE_KATAKANA);
            SET_KEY_DOWN(KeyState, VK_DBE_ALPHANUMERIC, bAlphaNumeric);
            SET_KEY_LOCKED(KeyState, VK_DBE_ALPHANUMERIC, bAlphaNumeric);
            SET_KEY_DOWN(KeyState, VK_DBE_HIRAGANA, bHiragana);
            SET_KEY_LOCKED(KeyState, VK_DBE_HIRAGANA, bHiragana);
            SET_KEY_DOWN(KeyState, VK_DBE_KATAKANA, bKatakana);
            SET_KEY_LOCKED(KeyState, VK_DBE_KATAKANA, bKatakana);

            bFullShape = (dwConversion & IME_CMODE_FULLSHAPE);
            SET_KEY_DOWN(KeyState, VK_DBE_DBCSCHAR, bFullShape);
            SET_KEY_LOCKED(KeyState, VK_DBE_DBCSCHAR, bFullShape);
            SET_KEY_DOWN(KeyState, VK_DBE_SBCSCHAR, !bFullShape);
            SET_KEY_LOCKED(KeyState, VK_DBE_SBCSCHAR, !bFullShape);

            bRoman = (dwConversion & IME_CMODE_ROMAN);
            SET_KEY_DOWN(KeyState, VK_DBE_ROMAN, bRoman);
            SET_KEY_LOCKED(KeyState, VK_DBE_ROMAN, bRoman);
            SET_KEY_DOWN(KeyState, VK_DBE_NOROMAN, !bRoman);
            SET_KEY_LOCKED(KeyState, VK_DBE_NOROMAN, !bRoman);

            bCharCode = (dwConversion & IME_CMODE_CHARCODE);
            SET_KEY_DOWN(KeyState, VK_DBE_CODEINPUT, bCharCode);
            SET_KEY_LOCKED(KeyState, VK_DBE_CODEINPUT, bCharCode);
            SET_KEY_DOWN(KeyState, VK_DBE_NOCODEINPUT, !bCharCode);
            SET_KEY_LOCKED(KeyState, VK_DBE_NOCODEINPUT, !bCharCode);
            break;

        case LANG_KOREAN:
            SET_KEY_LOCKED(KeyState, VK_HANGUL, (dwConversion & IME_CMODE_NATIVE));
            SET_KEY_LOCKED(KeyState, VK_JUNJA, (dwConversion & IME_CMODE_FULLSHAPE));
            SET_KEY_LOCKED(KeyState, VK_HANJA, (dwConversion & IME_CMODE_HANJACONVERT));
            break;

        default:
            break;
    }
}

DWORD
NTAPI
NtUserNotifyIMEStatus(HWND hwnd, BOOL fOpen, DWORD dwConversion)
{
    PWND pwnd;
    PTHREADINFO pti;
    HKL hKL;

    UserEnterExclusive();

    if (!IS_IMM_MODE())
    {
        ERR("!IS_IMM_MODE()\n");
        goto Quit;
    }

    pwnd = ValidateHwndNoErr(hwnd);
    if (!pwnd)
        goto Quit;

    pti = pwnd->head.pti;
    if (!pti || !gptiForeground)
        goto Quit;
    if (pti != gptiForeground && pti->MessageQueue != gptiForeground->MessageQueue)
        goto Quit;
    if (ghIMC == pwnd->hImc && gfImeOpen == !!fOpen && gdwImeConversion == dwConversion)
        goto Quit;

    ghIMC = pwnd->hImc;
    if (ghIMC)
    {
        gfImeOpen = !!fOpen;
        gdwImeConversion = dwConversion;
        UserSetImeConversionKeyState(pti, (fOpen ? dwConversion : IME_CMODE_ALPHANUMERIC));
    }

    if (ISITHOOKED(WH_SHELL))
    {
        hKL = (pti->KeyboardLayout ? pti->KeyboardLayout->hkl : NULL);
        co_HOOK_CallHooks(WH_SHELL, HSHELL_LANGUAGE, (WPARAM)hwnd, (LPARAM)hKL);
    }

    // TODO:

Quit:
    UserLeave();
    return 0;
}

BOOL
NTAPI
NtUserDisableThreadIme(
    DWORD dwThreadID)
{
    PTHREADINFO pti, ptiCurrent;
    PPROCESSINFO ppi;
    BOOL ret = FALSE;

    UserEnterExclusive();

    if (!IS_IMM_MODE())
    {
        ERR("!IS_IMM_MODE()\n");
        EngSetLastError(ERROR_CALL_NOT_IMPLEMENTED);
        goto Quit;
    }

    ptiCurrent = GetW32ThreadInfo();

    if (dwThreadID == INVALID_THREAD_ID)
    {
        ppi = ptiCurrent->ppi;
        ppi->W32PF_flags |= W32PF_DISABLEIME;

Retry:
        for (pti = ppi->ptiList; pti; pti = pti->ptiSibling)
        {
            pti->TIF_flags |= TIF_DISABLEIME;

            if (pti->spwndDefaultIme)
            {
                co_UserDestroyWindow(pti->spwndDefaultIme);
                pti->spwndDefaultIme = NULL;
                goto Retry; /* The contents of ppi->ptiList may be changed. */
            }
        }
    }
    else
    {
        if (dwThreadID == 0)
        {
            pti = ptiCurrent;
        }
        else
        {
            pti = IntTID2PTI(UlongToHandle(dwThreadID));

            /* The thread needs to reside in the current process. */
            if (!pti || pti->ppi != ptiCurrent->ppi)
                goto Quit;
        }

        pti->TIF_flags |= TIF_DISABLEIME;

        if (pti->spwndDefaultIme)
        {
            co_UserDestroyWindow(pti->spwndDefaultIme);
            pti->spwndDefaultIme = NULL;
        }
    }

    ret = TRUE;

Quit:
    UserLeave();
    return ret;
}

DWORD
NTAPI
NtUserGetAppImeLevel(HWND hWnd)
{
    DWORD ret = 0;
    PWND pWnd;
    PTHREADINFO pti;

    UserEnterShared();

    pWnd = ValidateHwndNoErr(hWnd);
    if (!pWnd)
        goto Quit;

    if (!IS_IMM_MODE())
    {
        ERR("!IS_IMM_MODE()\n");
        EngSetLastError(ERROR_CALL_NOT_IMPLEMENTED);
        goto Quit;
    }

    pti = PsGetCurrentThreadWin32Thread();
    if (pWnd->head.pti->ppi == pti->ppi)
        ret = (DWORD)(ULONG_PTR)UserGetProp(pWnd, AtomImeLevel, TRUE);

Quit:
    UserLeave();
    return ret;
}

// Win: GetImeInfoEx
BOOL FASTCALL UserGetImeInfoEx(LPVOID pUnknown, PIMEINFOEX pInfoEx, IMEINFOEXCLASS SearchType)
{
    PKL pkl, pklHead;

    if (!gspklBaseLayout)
        return FALSE;

    pkl = pklHead = gspklBaseLayout;

    /* Find the matching entry from the list and get info */
    if (SearchType == ImeInfoExKeyboardLayout)
    {
        do
        {
            if (pInfoEx->hkl == pkl->hkl)
            {
                if (!pkl->piiex)
                    break;

                *pInfoEx = *pkl->piiex;
                return TRUE;
            }

            pkl = pkl->pklNext;
        } while (pkl != pklHead);
    }
    else if (SearchType == ImeInfoExImeFileName)
    {
        do
        {
            if (pkl->piiex &&
                _wcsnicmp(pkl->piiex->wszImeFile, pInfoEx->wszImeFile,
                          RTL_NUMBER_OF(pkl->piiex->wszImeFile)) == 0)
            {
                *pInfoEx = *pkl->piiex;
                return TRUE;
            }

            pkl = pkl->pklNext;
        } while (pkl != pklHead);
    }
    else
    {
        /* Do nothing */
    }

    return FALSE;
}

BOOL
NTAPI
NtUserGetImeInfoEx(
    PIMEINFOEX pImeInfoEx,
    IMEINFOEXCLASS SearchType)
{
    IMEINFOEX ImeInfoEx;
    BOOL ret = FALSE;

    UserEnterShared();

    if (!IS_IMM_MODE())
    {
        ERR("!IS_IMM_MODE()\n");
        goto Quit;
    }

    _SEH2_TRY
    {
        ProbeForWrite(pImeInfoEx, sizeof(*pImeInfoEx), 1);
        ImeInfoEx = *pImeInfoEx;
    }
    _SEH2_EXCEPT(EXCEPTION_EXECUTE_HANDLER)
    {
        goto Quit;
    }
    _SEH2_END;

    ret = UserGetImeInfoEx(NULL, &ImeInfoEx, SearchType);
    if (!ret)
        goto Quit;

    _SEH2_TRY
    {
        *pImeInfoEx = ImeInfoEx;
    }
    _SEH2_EXCEPT(EXCEPTION_EXECUTE_HANDLER)
    {
        ret = FALSE;
    }
    _SEH2_END;

Quit:
    UserLeave();
    return ret;
}

BOOL
NTAPI
NtUserSetAppImeLevel(HWND hWnd, DWORD dwLevel)
{
    BOOL ret = FALSE;
    PWND pWnd;
    PTHREADINFO pti;

    UserEnterExclusive();

    if (!IS_IMM_MODE())
    {
        ERR("!IS_IMM_MODE()\n");
        EngSetLastError(ERROR_CALL_NOT_IMPLEMENTED);
        goto Quit;
    }

    pWnd = ValidateHwndNoErr(hWnd);
    if (!pWnd)
        goto Quit;

    pti = PsGetCurrentThreadWin32Thread();
    if (pWnd->head.pti->ppi == pti->ppi)
        ret = UserSetProp(pWnd, AtomImeLevel, (HANDLE)(ULONG_PTR)dwLevel, TRUE);

Quit:
    UserLeave();
    return ret;
}

// Win: SetImeInfoEx
BOOL FASTCALL UserSetImeInfoEx(LPVOID pUnknown, PIMEINFOEX pImeInfoEx)
{
    PKL pklHead, pkl;

    pkl = pklHead = gspklBaseLayout;

    do
    {
        if (pkl->hkl != pImeInfoEx->hkl)
        {
            pkl = pkl->pklNext;
            continue;
        }

        if (!pkl->piiex)
            return FALSE;

        if (!pkl->piiex->fLoadFlag)
            *pkl->piiex = *pImeInfoEx;

        return TRUE;
    } while (pkl != pklHead);

    return FALSE;
}

BOOL
NTAPI
NtUserSetImeInfoEx(PIMEINFOEX pImeInfoEx)
{
    BOOL ret = FALSE;
    IMEINFOEX ImeInfoEx;

    UserEnterExclusive();

    if (!IS_IMM_MODE())
    {
        ERR("!IS_IMM_MODE()\n");
        goto Quit;
    }

    _SEH2_TRY
    {
        ProbeForRead(pImeInfoEx, sizeof(*pImeInfoEx), 1);
        ImeInfoEx = *pImeInfoEx;
    }
    _SEH2_EXCEPT(EXCEPTION_EXECUTE_HANDLER)
    {
        goto Quit;
    }
    _SEH2_END;

    ret = UserSetImeInfoEx(NULL, &ImeInfoEx);

Quit:
    UserLeave();
    return ret;
}

// Choose the preferred owner of the IME window.
// Win: ImeSetFutureOwner
VOID FASTCALL IntImeSetFutureOwner(PWND pImeWnd, PWND pwndOwner)
{
    PWND pwndNode, pwndNextOwner, pwndParent, pwndSibling;
    PTHREADINFO pti = pImeWnd->head.pti;

    if (!pwndOwner || (pwndOwner->style & WS_CHILD)) // invalid owner
        return;

    // Get the top-level owner of the same thread
    for (pwndNode = pwndOwner; ; pwndNode = pwndNextOwner)
    {
        pwndNextOwner = pwndNode->spwndOwner;
        if (!pwndNextOwner || pwndNextOwner->head.pti != pti)
            break;
    }

    // Don't choose the IME-like windows and the bottom-most windows unless necessary.
    if (IS_WND_IMELIKE(pwndNode) ||
        ((pwndNode->state2 & WNDS2_BOTTOMMOST) && !(pwndOwner->state2 & WNDS2_BOTTOMMOST)))
    {
        pwndNode = pwndOwner;
    }

    pwndParent = pwndNode->spwndParent;
    if (!pwndParent || pwndOwner != pwndNode)
    {
        pImeWnd->spwndOwner = pwndNode;
        return;
    }

    for (pwndSibling = pwndParent->spwndChild; pwndSibling; pwndSibling = pwndSibling->spwndNext)
    {
        if (pwndNode->head.pti != pwndSibling->head.pti)
            continue;

        if (IS_WND_MENU(pwndSibling) || IS_WND_IMELIKE(pwndSibling))
            continue;

        if (pwndSibling->state2 & WNDS2_INDESTROY)
            continue;

        if (pwndNode == pwndSibling || (pwndSibling->style & WS_CHILD))
            continue;

        if (pwndSibling->spwndOwner == NULL ||
            pwndSibling->head.pti != pwndSibling->spwndOwner->head.pti)
        {
            pwndNode = pwndSibling;
            break;
        }
    }

    pImeWnd->spwndOwner = pwndNode;
}

// Get the last non-IME-like top-most window on the desktop.
// Win: GetLastTopMostWindowNoIME
PWND FASTCALL IntGetLastTopMostWindowNoIME(PWND pImeWnd)
{
    PWND pwndNode, pwndOwner, pwndLastTopMost = NULL;
    BOOL bFound;

    pwndNode = UserGetDesktopWindow();
    if (!pwndNode || pwndNode->spwndChild == NULL)
        return NULL;

    for (pwndNode = pwndNode->spwndChild;
         pwndNode && (pwndNode->ExStyle & WS_EX_TOPMOST);
         pwndNode = pwndNode->spwndNext)
    {
        bFound = FALSE;

        if (IS_WND_IMELIKE(pwndNode)) // An IME-like window
        {
            // Search the IME window from owners
            for (pwndOwner = pwndNode; pwndOwner; pwndOwner = pwndOwner->spwndOwner)
            {
                if (pImeWnd == pwndOwner)
                {
                    bFound = TRUE;
                    break;
                }
            }
        }

        if (!bFound)
            pwndLastTopMost = pwndNode;
    }

    return pwndLastTopMost;
}

// Adjust the ordering of the windows around the IME window.
// Win: ImeSetTopMost
VOID FASTCALL IntImeSetTopMost(PWND pImeWnd, BOOL bTopMost, PWND pwndInsertBefore)
{
    PWND pwndParent, pwndChild, pwndNode, pwndNext, pwndInsertAfter = NULL;
    PWND pwndInsertAfterSave;

    pwndParent = pImeWnd->spwndParent;
    if (!pwndParent)
        return;

    pwndChild = pwndParent->spwndChild;

    if (!bTopMost)
    {
        // Calculate pwndInsertAfter
        pwndInsertAfter = IntGetLastTopMostWindowNoIME(pImeWnd);
        if (pwndInsertBefore)
        {
            for (pwndNode = pwndInsertAfter; pwndNode; pwndNode = pwndNode->spwndNext)
            {
                if (pwndNode->spwndNext == pwndInsertBefore)
                    break;

                if (pwndNode == pImeWnd)
                    return;
            }

            if (!pwndNode)
                return;

            pwndInsertAfter = pwndNode;
        }

        // Adjust pwndInsertAfter if the owner is bottom-most
        if (pImeWnd->spwndOwner->state2 & WNDS2_BOTTOMMOST)
        {
            for (pwndNode = pwndInsertAfter; pwndNode; pwndNode = pwndNode->spwndNext)
            {
                if (pwndNode == pImeWnd->spwndOwner)
                    break;

                if (!IS_WND_IMELIKE(pwndNode))
                    pwndInsertAfter = pwndNode;
            }
        }
    }

    pwndInsertAfterSave = pwndInsertAfter;

    while (pwndChild)
    {
        pwndNext = pwndChild->spwndNext;

        // If pwndChild is a good IME-like window, ...
        if (IS_WND_IMELIKE(pwndChild) && pwndChild != pwndInsertAfter &&
            pwndChild->head.pti == pImeWnd->head.pti)
        {
            // Find pImeWnd from the owners
            for (pwndNode = pwndChild; pwndNode; pwndNode = pwndNode->spwndOwner)
            {
                if (pwndNode != pImeWnd)
                    continue;

                // Adjust the ordering and the linking
                IntUnlinkWindow(pwndChild);

                if (bTopMost)
                    pwndChild->ExStyle |= WS_EX_TOPMOST;
                else
                    pwndChild->ExStyle &= ~WS_EX_TOPMOST;

                if (!pwndInsertAfter)
                    IntLinkHwnd(pwndChild, HWND_TOP);
                else
                    IntLinkHwnd(pwndChild, UserHMGetHandle(pwndInsertAfter));

                // Update the preferred position
                pwndInsertAfter = pwndChild;
                break;
            }
        }

        // Get the next child, with ignoring pwndInsertAfterSave
        pwndChild = pwndNext;
        if (pwndChild && pwndChild == pwndInsertAfterSave && pwndInsertAfter)
            pwndChild = pwndInsertAfter->spwndNext;
    }
}

// Make the IME window top-most if necessary.
// Win: ImeCheckTopmost
VOID FASTCALL IntImeCheckTopmost(PWND pImeWnd)
{
    BOOL bTopMost;
    PWND pwndOwner = pImeWnd->spwndOwner, pwndInsertBefore = NULL;

    if (!pwndOwner)
        return;

    if (pImeWnd->head.pti != gptiForeground)
        pwndInsertBefore = pwndOwner;

    bTopMost = !!(pwndOwner->ExStyle & WS_EX_TOPMOST);
    IntImeSetTopMost(pImeWnd, bTopMost, pwndInsertBefore);
}

BOOL NTAPI
NtUserSetImeOwnerWindow(HWND hImeWnd, HWND hwndFocus)
{
    BOOL ret = FALSE;
    PWND pImeWnd, pwndFocus, pwndTopLevel, pwndNode, pwndActive;
    PTHREADINFO ptiIme;

    UserEnterExclusive();

    if (!IS_IMM_MODE())
    {
        ERR("!IS_IMM_MODE()\n");
        goto Quit;
    }

    pImeWnd = ValidateHwndNoErr(hImeWnd);
    if (!pImeWnd || pImeWnd->fnid != FNID_IME)
        goto Quit;

    pwndFocus = ValidateHwndNoErr(hwndFocus);
    if (pwndFocus)
    {
        if (IS_WND_IMELIKE(pwndFocus))
            goto Quit;

        pwndTopLevel = IntGetTopLevelWindow(pwndFocus);

        for (pwndNode = pwndTopLevel; pwndNode; pwndNode = pwndNode->spwndOwner)
        {
            if (pwndNode->pcls->atomClassName == gpsi->atomSysClass[ICLS_IME])
            {
                pwndTopLevel = NULL;
                break;
            }
        }

        pImeWnd->spwndOwner = pwndTopLevel;
        IntImeCheckTopmost(pImeWnd);
    }
    else
    {
        ptiIme = pImeWnd->head.pti;
        pwndActive = ptiIme->MessageQueue->spwndActive;

        if (!pwndActive || pwndActive != pImeWnd->spwndOwner)
        {
            if (pwndActive && ptiIme == pwndActive->head.pti && !IS_WND_IMELIKE(pwndActive))
            {
                pImeWnd->spwndOwner = pwndActive;
            }
            else
            {
                IntImeSetFutureOwner(pImeWnd, pImeWnd->spwndOwner);
            }

            IntImeCheckTopmost(pImeWnd);
        }
    }

    ret = TRUE;

Quit:
    UserLeave();
    return ret;
}

PVOID
AllocInputContextObject(PDESKTOP pDesk,
                        PTHREADINFO pti,
                        SIZE_T Size,
                        PVOID* HandleOwner)
{
    PTHRDESKHEAD ObjHead;

    ASSERT(Size > sizeof(*ObjHead));
    ASSERT(pti != NULL);

    if (!pDesk)
        pDesk = pti->rpdesk;

    ObjHead = DesktopHeapAlloc(pDesk, Size);
    if (!ObjHead)
        return NULL;

    RtlZeroMemory(ObjHead, Size);

    ObjHead->pSelf = ObjHead;
    ObjHead->rpdesk = pDesk;
    ObjHead->pti = pti;
    IntReferenceThreadInfo(pti);
    *HandleOwner = pti;
    pti->ppi->UserHandleCount++;

    return ObjHead;
}

VOID UserFreeInputContext(PVOID Object)
{
    PTHRDESKHEAD ObjHead = Object;
    PDESKTOP pDesk = ObjHead->rpdesk;
    PIMC pNode, pIMC = Object;
    PTHREADINFO pti;

    if (!pIMC)
        return;

    // Remove pIMC from the list except spDefaultImc
    pti = pIMC->head.pti;
    for (pNode = pti->spDefaultImc; pNode; pNode = pNode->pImcNext)
    {
        if (pNode->pImcNext == pIMC)
        {
            pNode->pImcNext = pIMC->pImcNext;
            break;
        }
    }

    DesktopHeapFree(pDesk, Object);

    pti->ppi->UserHandleCount--;
    IntDereferenceThreadInfo(pti);
}

BOOLEAN UserDestroyInputContext(PVOID Object)
{
    PIMC pIMC = Object;
    if (!pIMC || !UserMarkObjectDestroy(pIMC))
        return TRUE;

    return UserDeleteObject(UserHMGetHandle(pIMC), TYPE_INPUTCONTEXT);
}

// Win: DestroyInputContext
BOOL IntDestroyInputContext(PIMC pIMC)
{
    HIMC hIMC = UserHMGetHandle(pIMC);
    PTHREADINFO pti = pIMC->head.pti;
    PWND pwndChild;
    PWINDOWLIST pwl;
    HWND *phwnd;
    PWND pWnd;

    if (pti != gptiCurrent)
    {
        EngSetLastError(ERROR_ACCESS_DENIED);
        return FALSE;
    }

    if (pIMC == pti->spDefaultImc)
    {
        EngSetLastError(ERROR_INVALID_PARAMETER);
        return FALSE;
    }

    pwndChild = pti->rpdesk->pDeskInfo->spwnd->spwndChild;
    pwl = IntBuildHwndList(pwndChild, IACE_LIST | IACE_CHILDREN, pti);
    if (pwl)
    {
        for (phwnd = pwl->ahwnd; *phwnd != HWND_TERMINATOR; ++phwnd)
        {
            pWnd = UserGetObjectNoErr(gHandleTable, *phwnd, TYPE_WINDOW);
            if (pWnd && pWnd->hImc == hIMC)
                IntAssociateInputContext(pWnd, pti->spDefaultImc);
        }

        IntFreeHwndList(pwl);
    }

    UserDeleteObject(hIMC, TYPE_INPUTCONTEXT);
    return TRUE;
}

BOOL NTAPI NtUserDestroyInputContext(HIMC hIMC)
{
    BOOL ret = FALSE;
    PIMC pIMC;

    UserEnterExclusive();

    if (!IS_IMM_MODE())
    {
        EngSetLastError(ERROR_CALL_NOT_IMPLEMENTED);
        goto Quit;
    }

    pIMC = UserGetObjectNoErr(gHandleTable, hIMC, TYPE_INPUTCONTEXT);
    if (pIMC)
        ret = IntDestroyInputContext(pIMC);

Quit:
    UserLeave();
    return ret;
}

// Win: CreateInputContext
PIMC FASTCALL UserCreateInputContext(ULONG_PTR dwClientImcData)
{
    PIMC pIMC;
    PTHREADINFO pti = PsGetCurrentThreadWin32Thread();
    PDESKTOP pdesk = pti->rpdesk;

    if (!IS_IMM_MODE() || (pti->TIF_flags & TIF_DISABLEIME)) // Disabled?
    {
        ERR("IME is disabled\n");
        return NULL;
    }

    if (!pdesk) // No desktop?
        return NULL;

    // pti->spDefaultImc should be already set if non-first time.
    if (dwClientImcData && !pti->spDefaultImc)
        return NULL;

    // Create an input context user object.
    pIMC = UserCreateObject(gHandleTable, pdesk, pti, NULL, TYPE_INPUTCONTEXT, sizeof(IMC));
    if (!pIMC)
        return NULL;

    // Release the extra reference (UserCreateObject added 2 references).
    UserDereferenceObject(pIMC);

    if (dwClientImcData) // Non-first time.
    {
        // Insert pIMC to the second position (non-default) of the list.
        pIMC->pImcNext = pti->spDefaultImc->pImcNext;
        pti->spDefaultImc->pImcNext = pIMC;
    }
    else // First time. It's the default IMC.
    {
        // Add the first one (default) to the list.
        UserAssignmentLock((PVOID*)&pti->spDefaultImc, pIMC);
        pIMC->pImcNext = NULL;
    }

    pIMC->dwClientImcData = dwClientImcData; // Set it.
    return pIMC;
}

HIMC
NTAPI
NtUserCreateInputContext(ULONG_PTR dwClientImcData)
{
    PIMC pIMC;
    HIMC ret = NULL;

    UserEnterExclusive();

    if (!IS_IMM_MODE())
    {
        ERR("!IS_IMM_MODE()\n");
        EngSetLastError(ERROR_CALL_NOT_IMPLEMENTED);
        goto Quit;
    }

    if (!dwClientImcData)
    {
        EngSetLastError(ERROR_INVALID_PARAMETER);
        goto Quit;
    }

    pIMC = UserCreateInputContext(dwClientImcData);
    if (pIMC)
        ret = UserHMGetHandle(pIMC);

Quit:
    UserLeave();
    return ret;
}

// Win: AssociateInputContextEx
DWORD FASTCALL IntAssociateInputContextEx(PWND pWnd, PIMC pIMC, DWORD dwFlags)
{
    DWORD ret = 0;
    PWINDOWLIST pwl;
    BOOL bIgnoreNullImc = (dwFlags & IACE_IGNORENOCONTEXT);
    PTHREADINFO pti = pWnd->head.pti;
    PWND pwndTarget, pwndFocus = pti->MessageQueue->spwndFocus;
    HWND *phwnd;
    HIMC hIMC;

    if (dwFlags & IACE_DEFAULT)
    {
        pIMC = pti->spDefaultImc;
    }
    else
    {
        if (pIMC && pti != pIMC->head.pti)
            return 2;
    }

    if (pWnd->head.pti->ppi != GetW32ThreadInfo()->ppi ||
        (pIMC && pIMC->head.rpdesk != pWnd->head.rpdesk))
    {
        return 2;
    }

    if ((dwFlags & IACE_CHILDREN) && pWnd->spwndChild)
    {
        pwl = IntBuildHwndList(pWnd->spwndChild, IACE_CHILDREN | IACE_LIST, pti);
        if (pwl)
        {
            for (phwnd = pwl->ahwnd; *phwnd != HWND_TERMINATOR; ++phwnd)
            {
                pwndTarget = ValidateHwndNoErr(*phwnd);
                if (!pwndTarget)
                    continue;

                hIMC = (pIMC ? UserHMGetHandle(pIMC) : NULL);
                if (pwndTarget->hImc == hIMC || (bIgnoreNullImc && !pwndTarget->hImc))
                    continue;

                IntAssociateInputContext(pwndTarget, pIMC);
                if (pwndTarget == pwndFocus)
                    ret = 1;
            }

            IntFreeHwndList(pwl);
        }
    }

    if (!bIgnoreNullImc || pWnd->hImc)
    {
        hIMC = (pIMC ? UserHMGetHandle(pIMC) : NULL);
        if (pWnd->hImc != hIMC)
        {
            IntAssociateInputContext(pWnd, pIMC);
            if (pWnd == pwndFocus)
                ret = 1;
        }
    }

    return ret;
}

DWORD
NTAPI
NtUserAssociateInputContext(HWND hWnd, HIMC hIMC, DWORD dwFlags)
{
    DWORD ret = 2;
    PWND pWnd;
    PIMC pIMC;

    UserEnterExclusive();

    if (!IS_IMM_MODE())
    {
        ERR("!IS_IMM_MODE()\n");
        goto Quit;
    }

    pWnd = ValidateHwndNoErr(hWnd);
    if (!pWnd)
        goto Quit;

    pIMC = (hIMC ? UserGetObjectNoErr(gHandleTable, hIMC, TYPE_INPUTCONTEXT) : NULL);
    ret = IntAssociateInputContextEx(pWnd, pIMC, dwFlags);

Quit:
    UserLeave();
    return ret;
}

// Win: UpdateInputContext
BOOL FASTCALL UserUpdateInputContext(PIMC pIMC, DWORD dwType, DWORD_PTR dwValue)
{
    PTHREADINFO pti = GetW32ThreadInfo();
    PTHREADINFO ptiIMC = pIMC->head.pti;

    if (pti->ppi != ptiIMC->ppi) // Different process?
        return FALSE;

    switch (dwType)
    {
        case UIC_CLIENTIMCDATA:
            if (pIMC->dwClientImcData)
                return FALSE; // Already set

            pIMC->dwClientImcData = dwValue;
            break;

        case UIC_IMEWINDOW:
            if (!ValidateHwndNoErr((HWND)dwValue))
                return FALSE; // Invalid HWND

            pIMC->hImeWnd = (HWND)dwValue;
            break;

        default:
            return FALSE;
    }

    return TRUE;
}

BOOL
NTAPI
NtUserUpdateInputContext(
    HIMC hIMC,
    DWORD dwType,
    DWORD_PTR dwValue)
{
    PIMC pIMC;
    BOOL ret = FALSE;

    UserEnterExclusive();

    if (!IS_IMM_MODE())
    {
        ERR("!IS_IMM_MODE()\n");
        goto Quit;
    }

    pIMC = UserGetObject(gHandleTable, hIMC, TYPE_INPUTCONTEXT);
    if (!pIMC)
        goto Quit;

    ret = UserUpdateInputContext(pIMC, dwType, dwValue);

Quit:
    UserLeave();
    return ret;
}

DWORD_PTR
NTAPI
NtUserQueryInputContext(HIMC hIMC, DWORD dwType)
{
    PIMC pIMC;
    PTHREADINFO ptiIMC;
    DWORD_PTR ret = 0;

    UserEnterExclusive();

    if (!IS_IMM_MODE())
    {
        ERR("!IS_IMM_MODE()\n");
        goto Quit;
    }

    pIMC = UserGetObject(gHandleTable, hIMC, TYPE_INPUTCONTEXT);
    if (!pIMC)
        goto Quit;

    ptiIMC = pIMC->head.pti;

    switch (dwType)
    {
        case QIC_INPUTPROCESSID:
            ret = (DWORD_PTR)PsGetThreadProcessId(ptiIMC->pEThread);
            break;

        case QIC_INPUTTHREADID:
            ret = (DWORD_PTR)PsGetThreadId(ptiIMC->pEThread);
            break;

        case QIC_DEFAULTWINDOWIME:
            if (ptiIMC->spwndDefaultIme)
                ret = (DWORD_PTR)UserHMGetHandle(ptiIMC->spwndDefaultIme);
            break;

        case QIC_DEFAULTIMC:
            if (ptiIMC->spDefaultImc)
                ret = (DWORD_PTR)UserHMGetHandle(ptiIMC->spDefaultImc);
            break;
    }

Quit:
    UserLeave();
    return ret;
}

// Searchs a non-IME-related window of the same thread of pwndTarget,
// other than pwndTarget, around pwndParent. Returns TRUE if found.
//
// Win: IsChildSameThread
BOOL IntFindNonImeRelatedWndOfSameThread(PWND pwndParent, PWND pwndTarget)
{
    PWND pwnd, pwndOwner, pwndNode;
    PTHREADINFO ptiTarget = pwndTarget->head.pti;

    // For all the children of pwndParent, ...
    for (pwnd = pwndParent->spwndChild; pwnd; pwnd = pwnd->spwndNext)
    {
        if (pwnd == pwndTarget || pwnd->head.pti != ptiTarget || IS_WND_MENU(pwnd))
            continue;

        if (!IS_WND_CHILD(pwnd))
        {
            // Check if any IME-like owner.
            BOOL bFound1 = FALSE;
            for (pwndOwner = pwnd; pwndOwner; pwndOwner = pwndOwner->spwndOwner)
            {
                if (IS_WND_IMELIKE(pwndOwner))
                {
                    bFound1 = TRUE;
                    break;
                }
            }
            if (bFound1)
                continue; // Skip if any IME-like owner.
        }

        pwndNode = pwnd;

        if (IS_WND_CHILD(pwndNode))
        {
            // Check if any same-thread IME-like ancestor.
            BOOL bFound2 = FALSE;
            for (; IS_WND_CHILD(pwndNode); pwndNode = pwndNode->spwndParent)
            {
                if (pwndNode->head.pti != ptiTarget)
                    break;

                if (IS_WND_IMELIKE(pwndNode))
                {
                    bFound2 = TRUE;
                    break;
                }
            }
            if (bFound2)
                continue;
            // Now, pwndNode is non-child or non-same-thread window.
        }

        if (!IS_WND_CHILD(pwndNode)) // pwndNode is non-child
        {
            // Check if any same-thread IME-like owner.
            BOOL bFound3 = FALSE;
            for (; pwndNode; pwndNode = pwndNode->spwndOwner)
            {
                if (pwndNode->head.pti != ptiTarget)
                    break;

                if (IS_WND_IMELIKE(pwndNode))
                {
                    bFound3 = TRUE;
                    break;
                }
            }
            if (bFound3)
                continue;
        }

        return TRUE;
    }

    return FALSE;
}

// Determines whether the target window needs the IME window.
// Win: WantImeWindow(pwndParent, pwndTarget)
BOOL FASTCALL IntWantImeWindow(PWND pwndTarget)
{
    PDESKTOP rpdesk;
    PWINSTATION_OBJECT rpwinstaParent;
    PWND pwndNode, pwndParent = pwndTarget->spwndParent;

    if (gptiCurrent->TIF_flags & TIF_DISABLEIME)
        return FALSE;

    if (IS_WND_IMELIKE(pwndTarget))
        return FALSE;

    if (pwndTarget->fnid == FNID_DESKTOP || pwndTarget->fnid == FNID_MESSAGEWND)
        return FALSE;

    if (pwndTarget->state & WNDS_SERVERSIDEWINDOWPROC)
        return FALSE;

    rpdesk = pwndTarget->head.rpdesk;
    if (!rpdesk)
        return FALSE;

    rpwinstaParent = rpdesk->rpwinstaParent;
    if (!rpwinstaParent || (rpwinstaParent->Flags & WSS_NOIO))
        return FALSE;

    for (pwndNode = pwndParent; pwndNode; pwndNode = pwndNode->spwndParent)
    {
        if (rpdesk != pwndNode->head.rpdesk)
            break;

        if (pwndNode == rpdesk->spwndMessage)
            return FALSE;
    }

    return TRUE;
}

// Create the default IME window for the target window.
// Win: xxxCreateDefaultImeWindow(pwndTarget, ATOM, hInst)
PWND FASTCALL co_IntCreateDefaultImeWindow(PWND pwndTarget, HINSTANCE hInst)
{
    LARGE_UNICODE_STRING WindowName;
    UNICODE_STRING ClassName;
    PWND pImeWnd;
    PIMEUI pimeui;
    CREATESTRUCTW Cs;
    USER_REFERENCE_ENTRY Ref;
    PTHREADINFO pti = PsGetCurrentThreadWin32Thread();
    HANDLE pid = PsGetThreadProcessId(pti->pEThread);

    if (!(pti->spDefaultImc) && pid == gpidLogon)
        UserCreateInputContext(0);

    if (!(pti->spDefaultImc) || IS_WND_IMELIKE(pwndTarget) || !(pti->rpdesk->pheapDesktop))
        return NULL;

    if (IS_WND_CHILD(pwndTarget) && !(pwndTarget->style & WS_VISIBLE) &&
        pwndTarget->spwndParent->head.pti->ppi != pti->ppi)
    {
        return NULL;
    }

    RtlInitLargeUnicodeString(&WindowName, L"Default IME", 0);

    ClassName.Buffer = (PWCH)(ULONG_PTR)gpsi->atomSysClass[ICLS_IME];
    ClassName.Length = 0;
    ClassName.MaximumLength = 0;

    UserRefObjectCo(pwndTarget, &Ref);

    RtlZeroMemory(&Cs, sizeof(Cs));
    Cs.style = WS_POPUP | WS_DISABLED;
    Cs.hInstance = hInst;
    Cs.hwndParent = UserHMGetHandle(pwndTarget);
    Cs.lpszName = WindowName.Buffer;
    Cs.lpszClass = ClassName.Buffer;

    // NOTE: LARGE_UNICODE_STRING is compatible to LARGE_STRING.
    pImeWnd = co_UserCreateWindowEx(&Cs, &ClassName, (PLARGE_STRING)&WindowName, NULL, WINVER);
    if (pImeWnd)
    {
        pimeui = ((PIMEWND)pImeWnd)->pimeui;
        _SEH2_TRY
        {
            ProbeForWrite(pimeui, sizeof(IMEUI), 1);
            pimeui->fDefault = TRUE;
            if (IS_WND_CHILD(pwndTarget) && pwndTarget->spwndParent->head.pti != pti)
                pimeui->fChildThreadDef = TRUE;
        }
        _SEH2_EXCEPT(EXCEPTION_EXECUTE_HANDLER)
        {
            NOTHING;
        }
        _SEH2_END;
    }

    UserDerefObjectCo(pwndTarget);
    return pImeWnd;
}

// Determines whether the system can destroy the default IME window for the target child window.
// Win: ImeCanDestroyDefIMEforChild
BOOL FASTCALL IntImeCanDestroyDefIMEforChild(PWND pImeWnd, PWND pwndTarget)
{
    PWND pwndNode;
    PIMEUI pimeui;
    IMEUI SafeImeUI;

    pimeui = ((PIMEWND)pImeWnd)->pimeui;
    if (!pimeui || (LONG_PTR)pimeui == (LONG_PTR)-1)
        return FALSE;

    // Check IMEUI.fChildThreadDef
    _SEH2_TRY
    {
        ProbeForRead(pimeui, sizeof(IMEUI), 1);
        SafeImeUI = *pimeui;
        if (!SafeImeUI.fChildThreadDef)
            return FALSE;
    }
    _SEH2_EXCEPT(EXCEPTION_EXECUTE_HANDLER)
    {
        NOTHING;
    }
    _SEH2_END;

    // The parent of pwndTarget is NULL or of the same thread of pwndTarget?
    if (pwndTarget->spwndParent == NULL ||
        pwndTarget->head.pti == pwndTarget->spwndParent->head.pti)
    {
        return FALSE;
    }

    for (pwndNode = pwndTarget; pwndNode; pwndNode = pwndNode->spwndParent)
    {
        if (pwndNode == pwndNode->head.rpdesk->pDeskInfo->spwnd)
            break;

        if (IntFindNonImeRelatedWndOfSameThread(pwndNode->spwndParent, pwndTarget))
            return FALSE;
    }

    return TRUE;
}

// Determines whether the system can destroy the default IME window for the non-child target window.
// Win: ImeCanDestroyDefIME
BOOL FASTCALL IntImeCanDestroyDefIME(PWND pImeWnd, PWND pwndTarget)
{
    PWND pwndNode;
    PIMEUI pimeui;
    IMEUI SafeImeUI;

    pimeui = ((PIMEWND)pImeWnd)->pimeui;
    if (!pimeui || (LONG_PTR)pimeui == (LONG_PTR)-1)
        return FALSE;

    // Check IMEUI.fDestroy
    _SEH2_TRY
    {
        ProbeForRead(pimeui, sizeof(IMEUI), 1);
        SafeImeUI = *pimeui;
        if (SafeImeUI.fDestroy)
            return FALSE;
    }
    _SEH2_EXCEPT(EXCEPTION_EXECUTE_HANDLER)
    {
        NOTHING;
    }
    _SEH2_END;

    // Any ancestor of pImeWnd is pwndTarget?
    if (pImeWnd->spwndOwner)
    {
        for (pwndNode = pImeWnd->spwndOwner; pwndNode; pwndNode = pwndNode->spwndOwner)
        {
            if (pwndNode == pwndTarget)
                break;
        }

        if (!pwndNode)
            return FALSE;
    }

    // Any ancestor of pwndTarget is IME-like?
    for (pwndNode = pwndTarget; pwndNode; pwndNode = pwndNode->spwndOwner)
    {
        if (IS_WND_IMELIKE(pwndNode))
            return FALSE;
    }

    // Adjust the ordering and top-mode status
    IntImeSetFutureOwner(pImeWnd, pwndTarget);
    for (pwndNode = pImeWnd->spwndOwner; pwndNode; pwndNode = pwndNode->spwndNext)
    {
        if (pwndNode == pImeWnd)
            break;
    }
    if (pwndNode == pImeWnd)
        IntImeCheckTopmost(pImeWnd);

    // Is the owner of pImeWnd NULL or pwndTarget?
    if (pImeWnd->spwndOwner && pwndTarget != pImeWnd->spwndOwner)
        return FALSE;

    pImeWnd->spwndOwner = NULL;
    return TRUE;
}

/* EOF */