// THIS CODE AND INFORMATION IS PROVIDED "AS IS" WITHOUT WARRANTY OF
// ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING BUT NOT LIMITED TO
// THE IMPLIED WARRANTIES OF MERCHANTABILITY AND/OR FITNESS FOR A
// PARTICULAR PURPOSE.
//
// Copyright (c) Microsoft Corporation. All rights reserved

#include "Private.h"
#include "Globals.h"
#include "SampleIME.h"
#include "CandidateListUIPresenter.h"
#include "CompositionProcessorEngine.h"
#include "KeyHandlerEditSession.h"
#include "Compartment.h"

// 0xF003, 0xF004 are the keys that the touch keyboard sends for next/previous
#define THIRDPARTY_NEXTPAGE  static_cast<WORD>(0xF003)
#define THIRDPARTY_PREVPAGE  static_cast<WORD>(0xF004)

// Because the code mostly works with VKeys, here map a WCHAR back to a VKKey for certain
// vkeys that the IME handles specially
__inline UINT VKeyFromVKPacketAndWchar(UINT vk, WCHAR wch)
{
    UINT vkRet = vk;
    if (LOWORD(vk) == VK_PACKET)
    {
        if (wch == L' ')
        {
            vkRet = VK_SPACE;
        }
        else if ((wch >= L'0') && (wch <= L'9'))
        {
            vkRet = static_cast<UINT>(wch);
        }
        else if ((wch >= L'a') && (wch <= L'z'))
        {
            vkRet = (UINT)(L'A') + ((UINT)(L'z') - static_cast<UINT>(wch));
        }
        else if ((wch >= L'A') && (wch <= L'Z'))
        {
            vkRet = static_cast<UINT>(wch);
        }
        else if (wch == THIRDPARTY_NEXTPAGE)
        {
            vkRet = VK_NEXT;
        }
        else if (wch == THIRDPARTY_PREVPAGE)
        {
            vkRet = VK_PRIOR;
        }
    }
    return vkRet;
}

//+---------------------------------------------------------------------------
//
// _IsKeyEaten
//
//----------------------------------------------------------------------------

BOOL CSampleIME::_IsKeyEaten(_In_ ITfContext *pContext, UINT codeIn, _Out_ UINT *pCodeOut, _Out_writes_(1) WCHAR *pwch, _Out_opt_ _KEYSTROKE_STATE *pKeyState)
{
    pContext;

    *pCodeOut = codeIn;

    BOOL isOpen = FALSE;
    CCompartment CompartmentKeyboardOpen(_pThreadMgr, _tfClientId, GUID_COMPARTMENT_KEYBOARD_OPENCLOSE);
    CompartmentKeyboardOpen._GetCompartmentBOOL(isOpen);

    BOOL isDoubleSingleByte = FALSE;
    CCompartment CompartmentDoubleSingleByte(_pThreadMgr, _tfClientId, Global::SampleIMEGuidCompartmentDoubleSingleByte);
    CompartmentDoubleSingleByte._GetCompartmentBOOL(isDoubleSingleByte);

    BOOL isPunctuation = FALSE;
    CCompartment CompartmentPunctuation(_pThreadMgr, _tfClientId, Global::SampleIMEGuidCompartmentPunctuation);
    CompartmentPunctuation._GetCompartmentBOOL(isPunctuation);

    if (pKeyState)
    {
        pKeyState->Category = CATEGORY_NONE;
        pKeyState->Function = FUNCTION_NONE;
    }
    if (pwch)
    {
        *pwch = L'\0';
    }

    // if the keyboard is disabled, we don't eat keys.
    if (_IsKeyboardDisabled())
    {
        return FALSE;
    }

    //
    // Map virtual key to character code
    //
    BOOL isTouchKeyboardSpecialKeys = FALSE;
    WCHAR wch = ConvertVKey(codeIn);
    *pCodeOut = VKeyFromVKPacketAndWchar(codeIn, wch);
    if ((wch == THIRDPARTY_NEXTPAGE) || (wch == THIRDPARTY_PREVPAGE))
    {
        // We always eat the above softkeyboard special keys
        isTouchKeyboardSpecialKeys = TRUE;
        if (pwch)
        {
            *pwch = wch;
        }
    }

    // if the keyboard is closed, we don't eat keys, with the exception of the touch keyboard specials keys
    if (!isOpen && !isDoubleSingleByte && !isPunctuation)
    {
        return isTouchKeyboardSpecialKeys;
    }

    if (pwch)
    {
        *pwch = wch;
    }

    //
    // Get composition engine
    //
    CCompositionProcessorEngine *pCompositionProcessorEngine;
    pCompositionProcessorEngine = _pCompositionProcessorEngine;

    if (isOpen)
    {
        //
        // The candidate or phrase list handles the keys through ITfKeyEventSink.
        //
        // eat only keys that CKeyHandlerEditSession can handles.
        //
        if (pCompositionProcessorEngine->IsVirtualKeyNeed(*pCodeOut, pwch, _IsComposing(), _candidateMode, _isCandidateWithWildcard, pKeyState))
        {
            return TRUE;
        }
    }

    //
    // Punctuation
    //
    if (pCompositionProcessorEngine->IsPunctuation(wch))
    {
        if ((_candidateMode == CANDIDATE_NONE) && isPunctuation)
        {
            if (pKeyState)
            {
                pKeyState->Category = CATEGORY_COMPOSING;
                pKeyState->Function = FUNCTION_PUNCTUATION;
            }
            return TRUE;
        }
    }

    //
    // Double/Single byte
    //
    if (isDoubleSingleByte && pCompositionProcessorEngine->IsDoubleSingleByte(wch))
    {
        if (_candidateMode == CANDIDATE_NONE)
        {
            if (pKeyState)
            {
                pKeyState->Category = CATEGORY_COMPOSING;
                pKeyState->Function = FUNCTION_DOUBLE_SINGLE_BYTE;
            }
            return TRUE;
        }
    }

    return isTouchKeyboardSpecialKeys;
}

//+---------------------------------------------------------------------------
//
// ConvertVKey
//
//----------------------------------------------------------------------------

WCHAR CSampleIME::ConvertVKey(UINT code)
{
    //
    // Map virtual key to scan code
    //
    UINT scanCode = 0;
    scanCode = MapVirtualKey(code, 0);

    //
    // Keyboard state
    //
    BYTE abKbdState[256] = {'\0'};
    if (!GetKeyboardState(abKbdState))
    {
        return 0;
    }

    //
    // Map virtual key to character code
    //
    WCHAR wch = '\0';
    if (ToUnicode(code, scanCode, abKbdState, &wch, 1, 0) == 1)
    {
        return wch;
    }

    return 0;
}

//+---------------------------------------------------------------------------
//
// _IsKeyboardDisabled
//
//----------------------------------------------------------------------------

BOOL CSampleIME::_IsKeyboardDisabled()
{
    ITfDocumentMgr* pDocMgrFocus = nullptr;
    ITfContext* pContext = nullptr;
    BOOL isDisabled = FALSE;

    if ((_pThreadMgr->GetFocus(&pDocMgrFocus) != S_OK) ||
        (pDocMgrFocus == nullptr))
    {
        // if there is no focus document manager object, the keyboard 
        // is disabled.
        isDisabled = TRUE;
    }
    else if ((pDocMgrFocus->GetTop(&pContext) != S_OK) ||
        (pContext == nullptr))
    {
        // if there is no context object, the keyboard is disabled.
        isDisabled = TRUE;
    }
    else
    {
        CCompartment CompartmentKeyboardDisabled(_pThreadMgr, _tfClientId, GUID_COMPARTMENT_KEYBOARD_DISABLED);
        CompartmentKeyboardDisabled._GetCompartmentBOOL(isDisabled);

        CCompartment CompartmentEmptyContext(_pThreadMgr, _tfClientId, GUID_COMPARTMENT_EMPTYCONTEXT);
        CompartmentEmptyContext._GetCompartmentBOOL(isDisabled);
    }

    if (pContext)
    {
        pContext->Release();
    }

    if (pDocMgrFocus)
    {
        pDocMgrFocus->Release();
    }

    return isDisabled;
}

//+---------------------------------------------------------------------------
//
// ITfKeyEventSink::OnSetFocus
//
// Called by the system whenever this service gets the keystroke device focus.
//----------------------------------------------------------------------------

STDAPI CSampleIME::OnSetFocus(BOOL fForeground)
{
	fForeground;

    return S_OK;
}

//+---------------------------------------------------------------------------
//
// ITfKeyEventSink::OnTestKeyDown
//
// Called by the system to query this service wants a potential keystroke.
//----------------------------------------------------------------------------

STDAPI CSampleIME::OnTestKeyDown(ITfContext *pContext, WPARAM wParam, LPARAM lParam, BOOL *pIsEaten)
{
    Global::UpdateModifiers(wParam, lParam);

    _KEYSTROKE_STATE KeystrokeState;
    WCHAR wch = '\0';
    UINT code = 0;
    *pIsEaten = _IsKeyEaten(pContext, (UINT)wParam, &code, &wch, &KeystrokeState);

    if (KeystrokeState.Category == CATEGORY_INVOKE_COMPOSITION_EDIT_SESSION)
    {
        //
        // Invoke key handler edit session
        //
        KeystrokeState.Category = CATEGORY_COMPOSING;

        _InvokeKeyHandler(pContext, code, wch, (DWORD)lParam, KeystrokeState);
    }

    return S_OK;
}

//+---------------------------------------------------------------------------
//
// ITfKeyEventSink::OnKeyDown
//
// Called by the system to offer this service a keystroke.  If *pIsEaten == TRUE
// on exit, the application will not handle the keystroke.
//----------------------------------------------------------------------------

STDAPI CSampleIME::OnKeyDown(ITfContext *pContext, WPARAM wParam, LPARAM lParam, BOOL *pIsEaten)
{
    Global::UpdateModifiers(wParam, lParam);

    _KEYSTROKE_STATE KeystrokeState;
    WCHAR wch = '\0';
    UINT code = 0;

    *pIsEaten = _IsKeyEaten(pContext, (UINT)wParam, &code, &wch, &KeystrokeState);

    if (*pIsEaten)
    {
        bool needInvokeKeyHandler = true;
        //
        // Invoke key handler edit session
        //
        if (code == VK_ESCAPE)
        {
            KeystrokeState.Category = CATEGORY_COMPOSING;
        }

        // Always eat THIRDPARTY_NEXTPAGE and THIRDPARTY_PREVPAGE keys, but don't always process them.
        if ((wch == THIRDPARTY_NEXTPAGE) || (wch == THIRDPARTY_PREVPAGE))
        {
            needInvokeKeyHandler = !((KeystrokeState.Category == CATEGORY_NONE) && (KeystrokeState.Function == FUNCTION_NONE));
        }

        if (needInvokeKeyHandler)
        {
            _InvokeKeyHandler(pContext, code, wch, (DWORD)lParam, KeystrokeState);
        }
    }
    else if (KeystrokeState.Category == CATEGORY_INVOKE_COMPOSITION_EDIT_SESSION)
    {
        // Invoke key handler edit session
        KeystrokeState.Category = CATEGORY_COMPOSING;
        _InvokeKeyHandler(pContext, code, wch, (DWORD)lParam, KeystrokeState);
    }

    return S_OK;
}

//+---------------------------------------------------------------------------
//
// ITfKeyEventSink::OnTestKeyUp
//
// Called by the system to query this service wants a potential keystroke.
//----------------------------------------------------------------------------

STDAPI CSampleIME::OnTestKeyUp(ITfContext *pContext, WPARAM wParam, LPARAM lParam, BOOL *pIsEaten)
{
    if (pIsEaten == nullptr)
    {
        return E_INVALIDARG;
    }

    Global::UpdateModifiers(wParam, lParam);

    WCHAR wch = '\0';
    UINT code = 0;

    *pIsEaten = _IsKeyEaten(pContext, (UINT)wParam, &code, &wch, NULL);

    return S_OK;
}

//+---------------------------------------------------------------------------
//
// ITfKeyEventSink::OnKeyUp
//
// Called by the system to offer this service a keystroke.  If *pIsEaten == TRUE
// on exit, the application will not handle the keystroke.
//----------------------------------------------------------------------------

STDAPI CSampleIME::OnKeyUp(ITfContext *pContext, WPARAM wParam, LPARAM lParam, BOOL *pIsEaten)
{
    Global::UpdateModifiers(wParam, lParam);

    WCHAR wch = '\0';
    UINT code = 0;

    *pIsEaten = _IsKeyEaten(pContext, (UINT)wParam, &code, &wch, NULL);

    return S_OK;
}

//+---------------------------------------------------------------------------
//
// ITfKeyEventSink::OnPreservedKey
//
// Called when a hotkey (registered by us, or by the system) is typed.
//----------------------------------------------------------------------------

STDAPI CSampleIME::OnPreservedKey(ITfContext *pContext, REFGUID rguid, BOOL *pIsEaten)
{
	pContext;

    CCompositionProcessorEngine *pCompositionProcessorEngine;
    pCompositionProcessorEngine = _pCompositionProcessorEngine;

    pCompositionProcessorEngine->OnPreservedKey(rguid, pIsEaten, _GetThreadMgr(), _GetClientId());

    return S_OK;
}

//+---------------------------------------------------------------------------
//
// _InitKeyEventSink
//
// Advise a keystroke sink.
//----------------------------------------------------------------------------

BOOL CSampleIME::_InitKeyEventSink()
{
    ITfKeystrokeMgr* pKeystrokeMgr = nullptr;
    HRESULT hr = S_OK;

    if (FAILED(_pThreadMgr->QueryInterface(IID_ITfKeystrokeMgr, (void **)&pKeystrokeMgr)))
    {
        return FALSE;
    }

    hr = pKeystrokeMgr->AdviseKeyEventSink(_tfClientId, (ITfKeyEventSink *)this, TRUE);

    pKeystrokeMgr->Release();

    return (hr == S_OK);
}

//+---------------------------------------------------------------------------
//
// _UninitKeyEventSink
//
// Unadvise a keystroke sink.  Assumes we have advised one already.
//----------------------------------------------------------------------------

void CSampleIME::_UninitKeyEventSink()
{
    ITfKeystrokeMgr* pKeystrokeMgr = nullptr;

    if (FAILED(_pThreadMgr->QueryInterface(IID_ITfKeystrokeMgr, (void **)&pKeystrokeMgr)))
    {
        return;
    }

    pKeystrokeMgr->UnadviseKeyEventSink(_tfClientId);

    pKeystrokeMgr->Release();
}