/*
 * PROJECT:     ReactOS IMM32
 * LICENSE:     LGPL-2.1-or-later (https://spdx.org/licenses/LGPL-2.1-or-later)
 * PURPOSE:     Implementing IMM32 helper functions
 * COPYRIGHT:   Copyright 1998 Patrik Stridvall
 *              Copyright 2002, 2003, 2007 CodeWeavers, Aric Stewart
 *              Copyright 2017 James Tabor <james.tabor@reactos.org>
 *              Copyright 2018 Amine Khaldi <amine.khaldi@reactos.org>
 *              Copyright 2020 Oleg Dubinskiy <oleg.dubinskij2013@yandex.ua>
 *              Copyright 2020-2021 Katayama Hirofumi MZ <katayama.hirofumi.mz@gmail.com>
 */

#include "precomp.h"

WINE_DEFAULT_DEBUG_CHANNEL(imm);

HANDLE g_hImm32Heap = NULL;

LPWSTR APIENTRY Imm32WideFromAnsi(LPCSTR pszA)
{
    INT cch = lstrlenA(pszA);
    LPWSTR pszW = Imm32HeapAlloc(0, (cch + 1) * sizeof(WCHAR));
    if (pszW == NULL)
        return NULL;
    cch = MultiByteToWideChar(CP_ACP, MB_PRECOMPOSED, pszA, cch, pszW, cch + 1);
    pszW[cch] = 0;
    return pszW;
}

LPSTR APIENTRY Imm32AnsiFromWide(LPCWSTR pszW)
{
    INT cchW = lstrlenW(pszW);
    INT cchA = (cchW + 1) * sizeof(WCHAR);
    LPSTR pszA = Imm32HeapAlloc(0, cchA);
    if (!pszA)
        return NULL;
    cchA = WideCharToMultiByte(CP_ACP, 0, pszW, cchW, pszA, cchA, NULL, NULL);
    pszA[cchA] = 0;
    return pszA;
}

BOOL Imm32GetSystemLibraryPath(LPWSTR pszPath, DWORD cchPath, LPCWSTR pszFileName)
{
    if (!pszFileName[0] || !GetSystemDirectoryW(pszPath, cchPath))
        return FALSE;
    StringCchCatW(pszPath, cchPath, L"\\");
    StringCchCatW(pszPath, cchPath, pszFileName);
    return TRUE;
}

VOID APIENTRY LogFontAnsiToWide(const LOGFONTA *plfA, LPLOGFONTW plfW)
{
    size_t cch;
    RtlCopyMemory(plfW, plfA, offsetof(LOGFONTA, lfFaceName));
    StringCchLengthA(plfA->lfFaceName, _countof(plfA->lfFaceName), &cch);
    cch = MultiByteToWideChar(CP_ACP, MB_PRECOMPOSED, plfA->lfFaceName, (INT)cch,
                              plfW->lfFaceName, _countof(plfW->lfFaceName));
    if (cch > _countof(plfW->lfFaceName) - 1)
        cch = _countof(plfW->lfFaceName) - 1;
    plfW->lfFaceName[cch] = 0;
}

VOID APIENTRY LogFontWideToAnsi(const LOGFONTW *plfW, LPLOGFONTA plfA)
{
    size_t cch;
    RtlCopyMemory(plfA, plfW, offsetof(LOGFONTW, lfFaceName));
    StringCchLengthW(plfW->lfFaceName, _countof(plfW->lfFaceName), &cch);
    cch = WideCharToMultiByte(CP_ACP, 0, plfW->lfFaceName, (INT)cch,
                              plfA->lfFaceName, _countof(plfA->lfFaceName), NULL, NULL);
    if (cch > _countof(plfA->lfFaceName) - 1)
        cch = _countof(plfA->lfFaceName) - 1;
    plfA->lfFaceName[cch] = 0;
}

PWND FASTCALL ValidateHwndNoErr(HWND hwnd)
{
    PCLIENTINFO ClientInfo = GetWin32ClientInfo();
    INT index;
    PUSER_HANDLE_TABLE ht;
    PUSER_HANDLE_ENTRY he;
    WORD generation;

    /* See if the window is cached */
    if (hwnd == ClientInfo->CallbackWnd.hWnd)
        return ClientInfo->CallbackWnd.pWnd;

    if (!NtUserValidateHandleSecure(hwnd))
        return NULL;

    ht = g_SharedInfo.aheList; /* handle table */
    ASSERT(ht);
    /* ReactOS-Specific! */
    ASSERT(g_SharedInfo.ulSharedDelta != 0);
    he = (PUSER_HANDLE_ENTRY)((ULONG_PTR)ht->handles - g_SharedInfo.ulSharedDelta);

    index = (LOWORD(hwnd) - FIRST_USER_HANDLE) >> 1;
    if (index < 0 || index >= ht->nb_handles || he[index].type != TYPE_WINDOW)
        return NULL;

    generation = HIWORD(hwnd);
    if (generation != he[index].generation && generation && generation != 0xFFFF)
        return NULL;

    return (PWND)&he[index];
}

LPVOID APIENTRY Imm32HeapAlloc(DWORD dwFlags, DWORD dwBytes)
{
    if (!g_hImm32Heap)
    {
        g_hImm32Heap = RtlGetProcessHeap();
        if (g_hImm32Heap == NULL)
            return NULL;
    }
    return HeapAlloc(g_hImm32Heap, dwFlags, dwBytes);
}

BOOL APIENTRY
Imm32NotifyAction(HIMC hIMC, HWND hwnd, DWORD dwAction, DWORD_PTR dwIndex, DWORD_PTR dwValue,
                  DWORD_PTR dwCommand, DWORD_PTR dwData)
{
    DWORD dwLayout;
    HKL hKL;
    PIMEDPI pImeDpi;

    if (dwAction)
    {
        dwLayout = NtUserQueryInputContext(hIMC, 1);
        if (dwLayout)
        {
            /* find keyboard layout and lock it */
            hKL = GetKeyboardLayout(dwLayout);
            pImeDpi = ImmLockImeDpi(hKL);
            if (pImeDpi)
            {
                /* do notify */
                pImeDpi->NotifyIME(hIMC, dwAction, dwIndex, dwValue);

                ImmUnlockImeDpi(pImeDpi); /* unlock */
            }
        }
    }

    if (hwnd && dwCommand)
        SendMessageW(hwnd, WM_IME_NOTIFY, dwCommand, dwData);

    return TRUE;
}

DWORD APIENTRY Imm32AllocAndBuildHimcList(DWORD dwThreadId, HIMC **pphList)
{
#define INITIAL_COUNT 0x40
#define MAX_RETRY 10
    NTSTATUS Status;
    DWORD dwCount = INITIAL_COUNT, cRetry = 0;
    HIMC *phNewList;

    phNewList = Imm32HeapAlloc(0, dwCount * sizeof(HIMC));
    if (phNewList == NULL)
        return 0;

    Status = NtUserBuildHimcList(dwThreadId, dwCount, phNewList, &dwCount);
    while (Status == STATUS_BUFFER_TOO_SMALL)
    {
        Imm32HeapFree(phNewList);
        if (cRetry++ >= MAX_RETRY)
            return 0;

        phNewList = Imm32HeapAlloc(0, dwCount * sizeof(HIMC));
        if (phNewList == NULL)
            return 0;

        Status = NtUserBuildHimcList(dwThreadId, dwCount, phNewList, &dwCount);
    }

    if (NT_ERROR(Status) || !dwCount)
    {
        Imm32HeapFree(phNewList);
        return 0;
    }

    *pphList = phNewList;
    return dwCount;
#undef INITIAL_COUNT
#undef MAX_RETRY
}

/***********************************************************************
 *		ImmCreateIMCC(IMM32.@)
 */
HIMCC WINAPI ImmCreateIMCC(DWORD size)
{
    if (size < 4)
        size = 4;
    return LocalAlloc(LHND, size);
}

/***********************************************************************
 *       ImmDestroyIMCC(IMM32.@)
 */
HIMCC WINAPI ImmDestroyIMCC(HIMCC block)
{
    if (block)
        return LocalFree(block);
    return NULL;
}

/***********************************************************************
 *		ImmLockIMCC(IMM32.@)
 */
LPVOID WINAPI ImmLockIMCC(HIMCC imcc)
{
    if (imcc)
        return LocalLock(imcc);
    return NULL;
}

/***********************************************************************
 *		ImmUnlockIMCC(IMM32.@)
 */
BOOL WINAPI ImmUnlockIMCC(HIMCC imcc)
{
    if (imcc)
        return LocalUnlock(imcc);
    return FALSE;
}

/***********************************************************************
 *		ImmGetIMCCLockCount(IMM32.@)
 */
DWORD WINAPI ImmGetIMCCLockCount(HIMCC imcc)
{
    return LocalFlags(imcc) & LMEM_LOCKCOUNT;
}

/***********************************************************************
 *		ImmReSizeIMCC(IMM32.@)
 */
HIMCC WINAPI ImmReSizeIMCC(HIMCC imcc, DWORD size)
{
    if (!imcc)
        return NULL;
    return LocalReAlloc(imcc, size, LHND);
}

/***********************************************************************
 *		ImmGetIMCCSize(IMM32.@)
 */
DWORD WINAPI ImmGetIMCCSize(HIMCC imcc)
{
    if (imcc)
        return LocalSize(imcc);
    return 0;
}

/***********************************************************************
 *		ImmGetIMCLockCount(IMM32.@)
 */
DWORD WINAPI ImmGetIMCLockCount(HIMC hIMC)
{
    DWORD ret;
    HIMC hClientImc;
    PCLIENTIMC pClientImc;

    pClientImc = ImmLockClientImc(hIMC);
    if (pClientImc == NULL)
        return 0;

    ret = 0;
    hClientImc = pClientImc->hImc;
    if (hClientImc)
        ret = (LocalFlags(hClientImc) & LMEM_LOCKCOUNT);

    ImmUnlockClientImc(pClientImc);
    return ret;
}