// Platform implementation of EterLib/IME.h (40250 EterLib/IME.cpp).
// The edit buffer (m_wText, cursor, SetText/GetText, OnChar/InsertString, IsMax, the colour-tag aware cursor
// moves) and WMChar are the 40250 bodies verbatim. What 40250 gets from Win32 IMM/TSF — composition strings,
// the candidate list, the reading window, keyboard-layout code pages — has no counterpart under Godot: the
// host delivers committed characters only (Metin2PythonHost.ui_char -> WMChar, or InsertString for text the
// input code page cannot hold, which is what 40250's ResultProcess does with a GCS_RESULTSTR). Those entry
// points keep 40250's "no IME present" behaviour: no composition, empty candidate/reading lists.
#include "EterLib/StdAfx.h"
#include "EterLib/IME.h"
#include "EterLib/TextTag.h"
#include "EterLib/GrpTextInstance.h"
#include "EterLib/Util.h"

#include <algorithm>
#include <cwctype>

namespace
{
// 40250 s_aszIndicator[INDICATOR_NON_IME] (IME.cpp:67); CheckInputLocale overwrites it with the locale's
// two-letter abbreviation, which here is the locale code page's language.
wchar_t s_aszNonImeIndicator[3] = L"En";
}

/*---------------------------------------------------------------------------*/ /* Public */
CIME::CIME()
{
	ms_hWnd = NULL;

	ms_bCandidateList = false;
	ms_bReadingInformation = false;

	Clear();

	m_max = 0;
	m_userMax = 0;

	m_bOnlyNumberMode = FALSE;
	m_hOrgIMC = NULL;

	m_bEnablePaste = false;
	m_bUseDefaultIME = false;
}

CIME::~CIME()
{
}

// PORT: 40250 loads imm32.dll, disables Cicero, reads the keyboard layout and sets up the TSF sinks. The
// Godot host has no IMM context; only the part the edit buffer depends on — the input/output code page from
// CheckInputLocale and SetSupportLevel(2) — is kept.
bool CIME::Initialize(HWND hWnd)
{
	if(ms_bInitialized)
		return true;
	ms_hWnd = hWnd;

	ms_bDisableIMECompletely = true;
	ms_bInitialized = true;

	CheckInputLocale();
	ChangeInputLanguageWorker();
	SetSupportLevel(2);

	ms_bUILessMode = false;
	CheckToggleState();

	return true;
}

void CIME::Uninitialize()
{
	if ( !ms_bInitialized )
		return;
	ms_hWnd = NULL;
	m_hOrgIMC = NULL;
	ms_bInitialized = false;
}

void CIME::UseDefaultIME()
{
	m_bUseDefaultIME = true;
}

bool CIME::IsIMEEnabled()
{
	return ms_bImeEnabled;
}

// PORT: 40250 ImmAssociateContext()s the window; ms_bDisableIMECompletely (no imm32) forces bEnable=false,
// which is always the case here.
void CIME::EnableIME(bool bEnable)
{
	if (!ms_bInitialized || !ms_hWnd)
		return;
	if (ms_bDisableIMECompletely)
		bEnable = false;
	ms_bImeEnabled = bEnable;
	if (bEnable)
		CheckToggleState();
}

void CIME::DisableIME()
{
	EnableIME(false);
}

void CIME::EnableCaptureInput()
{
	ms_bCaptureInput = true;
}

void CIME::DisableCaptureInput()
{
	ms_bCaptureInput = false;
}

bool CIME::IsCaptureEnabled()
{
	return ms_bCaptureInput;
}

void CIME::Clear()
{
	ms_lastpos = 0;
	ms_curpos = 0;

	ms_compLen = 0;
	ms_ulbegin = 0;
	ms_ulend = 0;
}

int CIME::GetReading(std::string & rstrText)
{
	char reading[IMEREADING_MAXLEN];

	if(ms_wstrReading.size() == 0)
		return 0;
	int readingLen = WideCharToMultiByte(ms_uOutputCodePage, 0, &ms_wstrReading[0], ms_wstrReading.size(), reading, sizeof(reading), NULL, NULL);

	rstrText.append(GetCodePageText());
	rstrText.append(reading, reading + readingLen);

	return rstrText.size();
}

int CIME::GetReadingError()
{
	return ms_iReadingError;
}

void CIME::SetMax(int iMax)
{
	m_max = iMax;
}

void CIME::SetUserMax(int iMax)
{
	m_userMax = iMax;
}

void CIME::SetText(const char* szText, int len)
{
	ms_compLen = 0;
	ms_ulbegin = 0;
	ms_ulend = 0;

	const char* begin = szText;
	const char* end = begin + len;
	const char* iter = FindToken(begin, end);

	int m_wTextLen = sizeof(m_wText)/sizeof(wchar_t);

	ms_lastpos = MultiByteToWideChar(ms_uInputCodePage, 0, begin, iter-begin, m_wText, m_wTextLen);

	if (iter < end)
		ms_lastpos += MultiByteToWideChar(ReadToken(iter), 0, (iter+5), end-(iter+5), m_wText+ms_lastpos, m_wTextLen-ms_lastpos);

	ms_curpos = std::min(ms_curpos, ms_lastpos);
}

int  CIME::GetText(std::string & rstrText, bool addCodePage)
{
	int outCodePage = ms_uOutputCodePage;
	int dataCodePage;
	switch (outCodePage)
	{
		//case 1256: // ARABIC
		case 1268: // VIETNAM
			dataCodePage = CP_UTF8;
			break;
		default:
			dataCodePage = outCodePage;
	}

	int len = 0;
	char text[IMESTR_MAXLEN];

	len += WideCharToMultiByte(dataCodePage, 0, m_wText, ms_curpos, text, sizeof(text)-len, NULL, NULL);
	len += WideCharToMultiByte(dataCodePage, 0, m_wszComposition, ms_compLen, text+len, sizeof(text)-len, NULL, NULL);
	len += WideCharToMultiByte(dataCodePage, 0, m_wText+ms_curpos, ms_lastpos-ms_curpos, text+len, sizeof(text)-len, NULL, NULL);

	int i;
	for(i=0; i<len; ++i)
		if((BYTE)text[i] > 0x7F) break;

	if(i == len)
	{
		rstrText.append(text, text+len);
	}
	else
	{
		rstrText.append(text, text+i);

		//if (addCodePage)
		//	rstrText.append(GetCodePageText());

		rstrText.append(text+i, text+len);
	}

	return rstrText.size();
}

const char* CIME::GetCodePageText()
{
	static char szCodePage[16];

	const int defCodePage = GetDefaultCodePage();
	const int outCodePage = ms_uOutputCodePage;

	if (outCodePage != defCodePage)
	{
		sprintf(szCodePage, "@%04d", outCodePage);
	}
	else
	{
		szCodePage[0] = 0;
	}

	return szCodePage;
}

int CIME::GetCodePage()
{
	return ms_uOutputCodePage;
}

int CIME::GetCandidatePageCount()
{
	return ms_dwCandidatePageSize;
}

int CIME::GetCandidateCount()
{
	return ms_dwCandidateCount;
}

int  CIME::GetCandidate(DWORD index, std::string & rstrText)
{
	if(index >= MAX_CANDLIST)
		return 0;

	LPCWSTR wszText = ms_wszCandidate[index];
	if(wszText == NULL)
		return 0;

	int wTextLen = wcslen(wszText);
	if(wTextLen == 0)
		return 0;

	char text[IMESTR_MAXLEN];
	int len = ::WideCharToMultiByte(CP_UTF8, 0, wszText, wTextLen, text, sizeof(text), 0, 0);

	rstrText.append("@9999");
	rstrText.append(text, text+len);

	return wTextLen;
}

int CIME::GetCandidateSelection()
{
	return ms_dwCandidateSelection;
}

// PORT: 40250 ImmSetConversionStatus / ImmGetConversionStatus. Without an IMM context the conversion mode is
// the alphanumeric one (IME_CMODE_ALPHANUMERIC == 0) and cannot be changed.
void CIME::SetInputMode(DWORD)
{
}

DWORD CIME::GetInputMode()
{
	return 0;
}

void CIME::SetNumberMode()
{
	m_bOnlyNumberMode = TRUE;
}

void CIME::SetStringMode()
{
	m_bOnlyNumberMode = FALSE;
}

void CIME::AddExceptKey(wchar_t key)
{
	m_exceptKey.push_back(key);
}

void CIME::ClearExceptKey()
{
	m_exceptKey.clear();
}

bool CIME::__IsWritable(wchar_t key)
{
	if ( m_exceptKey.end() == std::find(m_exceptKey.begin(),m_exceptKey.end(),key) )
		return true;
	else
		return false;
}

void CIME::EnablePaste(bool bFlag)
{
	m_bEnablePaste = bFlag;
}

// PORT: 40250 reads CF_TEXT from the Win32 clipboard. The host clipboard is not wired to the extension yet,
// so this pastes nothing (the same as an empty clipboard).
void CIME::PasteTextFromClipBoard()
{
	if (!m_bEnablePaste)
		return;
}

// PORT: 40250 cancels the IMM composition string and closes the candidate list. There is no composition
// here; the candidate-list close (and its event) is kept.
void CIME::FinalizeString(bool)
{
	static bool s_bProcessing = false; // to avoid infinite recursion
	if ( !ms_bInitialized || s_bProcessing )
		return;
	s_bProcessing = true;
	CloseCandidateList();
	s_bProcessing = false;
}

int CIME::GetCompLen()
{
	return ms_compLen;
}

int CIME::GetULBegin()
{
	return ms_ulbegin;
}

int CIME::GetULEnd()
{
	return ms_ulend;
}

void CIME::CloseCandidateList()
{
	ms_bCandidateList = false;
	ms_dwCandidateCount = 0;
	memset(&ms_wszCandidate, 0, sizeof(ms_wszCandidate));
	if(ms_pEvent)
		ms_pEvent->OnCloseCandidateList();
}

void CIME::CloseReadingInformation()
{
	CIME::ms_bReadingInformation = false;
	if(CIME::ms_pEvent)
		CIME::ms_pEvent->OnCloseReadingWnd();
}

// PORT: 40250 re-reads the keyboard layout (GETLANG) and re-applies the IME support level when the language
// changed. The host has one fixed input locale, so only the toggle check and the code-page event remain.
void CIME::ChangeInputLanguage()
{
	CheckToggleState();
	ChangeInputLanguageWorker();

	if(ms_pEvent)
		ms_pEvent->OnChangeCodePage();
}

void CIME::ChangeInputLanguageWorker()
{
	if ( !ms_bUILessMode )
		ms_iCandListIndexBase = 1;
	SetupImeApi();
}

// PORT: 40250 forces level 3 for the Korean keyboard layout; there is no keyboard layout here.
void CIME::SetSupportLevel( DWORD dwImeLevel )
{
	if ( dwImeLevel < 2 || 3 < dwImeLevel )
		return;
	ms_dwIMELevel = dwImeLevel;
	// cancel current composition string.
	FinalizeString();
}

LRESULT CIME::WMInputLanguage(HWND, UINT, WPARAM, LPARAM)
{
	ChangeInputLanguage();
	return 0;
}

LRESULT CIME::WMStartComposition(HWND, UINT, WPARAM, LPARAM)
{
	return 1L;
}

// PORT: 40250 pulls GCS_RESULTSTR/GCS_COMPSTR out of the IMM context. The host never sends compositions.
LRESULT CIME::WMComposition(HWND, UINT, WPARAM, LPARAM)
{
	return 0;
}

LRESULT CIME::WMEndComposition(HWND, UINT, WPARAM, LPARAM)
{
	ms_compLen = 0;
	ms_ulbegin = 0;
	ms_ulend = 0;

	if(ms_pEvent)
		ms_pEvent->OnUpdate();

	return 0L;
}

// PORT: 40250 handles IMN_* candidate/reading/toggle notifications from IMM; none are sent here.
LRESULT CIME::WMNotify(HWND, UINT, WPARAM, LPARAM)
{
	return 0;
}

LRESULT CIME::WMChar(HWND /*hWnd*/, UINT /*uiMsg*/, WPARAM wParam, LPARAM lParam)
{
	unsigned char c = (unsigned char)(wParam & 0xff);

	switch (c)
	{
	case 8:
		if(ms_bCaptureInput == false)
			return 0;
		if (ms_curpos > 0)
		{
			DecCurPos();
			DelCurPos();
		}
		if(ms_pEvent)
			ms_pEvent->OnUpdate();
		return 0;
		break;

	default:
		if(ms_pEvent) {
			if (ms_pEvent->OnWM_CHAR(wParam, lParam))
				break;
		}
		if(ms_bCaptureInput == false)
			return 0;
		wchar_t w[10];
		MultiByteToWideChar(ms_uInputCodePage, 0, (char*)&c, 1, w, 1);

		OnChar(w[0]);
		if (w[0] == L'|')
			OnChar(w[0]);
		if(ms_pEvent)
			ms_pEvent->OnUpdate();
		break;
	}

	return 0;
}

/*---------------------------------------------------------------------------*/ /* Protected */
void CIME::IncCurPos()
{
	if (ms_curpos < ms_lastpos)
	{
		int pos = FindColorTagEndPosition(m_wText + ms_curpos, ms_lastpos - ms_curpos);

		if (pos > 0)
			ms_curpos = std::min(ms_lastpos, std::max(0, ms_curpos + (pos + 1)));
		else
			++ms_curpos;
		//++ms_curpos;
	}
}

void CIME::DecCurPos()
{
	if (ms_curpos > 0)
	{
		int pos = FindColorTagStartPosition(m_wText + ms_curpos - 1, ms_curpos);

		if (pos > 0)
			ms_curpos = std::min(ms_lastpos, std::max(0, ms_curpos - (pos + 1)));
		else
			--ms_curpos;
		//--ms_curpos;
	}
}

int CIME::GetCurPos()
{
	int pos = GetTextTagOutputLen(m_wText, ms_curpos);
	return pos;
	//return ms_curpos;
}

void CIME::SetCurPos(int offset)
{
	if (offset < 0 || offset > ms_lastpos)
	{
		ms_curpos = ms_lastpos;
		return;
	}
	else
	{
		// offset is a position in the rendered text, so it has to be mapped back to the buffer.
		//ms_curpos = min(ms_lastpos, offset);
		ms_curpos = std::min(ms_lastpos, GetTextTagInternalPosFromRenderPos(m_wText, ms_lastpos, offset));
	}
}

void CIME::DelCurPos()
{
	if (ms_curpos < ms_lastpos)
	{
		int eraseCount = FindColorTagEndPosition(m_wText + ms_curpos, ms_lastpos - ms_curpos) + 1;
		// PORT: 40250 wcscpy()s the overlapping tail down; that is undefined for overlapping buffers, and the
		// buffer is not guaranteed NUL-terminated at ms_lastpos, so move exactly the live tail.
		memmove(m_wText + ms_curpos, m_wText + ms_curpos + eraseCount, sizeof(wchar_t) * (ms_lastpos - ms_curpos - eraseCount));
		ms_lastpos -= eraseCount;
		ms_curpos = std::min(ms_lastpos, ms_curpos);
	}
}

void CIME::PasteString(const char * str)
{
	const char * begin = str;
	const char * end = str + strlen(str);
	wchar_t m_wText[IMESTR_MAXLEN];
	int wstrLen = MultiByteToWideChar(ms_uInputCodePage, 0, begin, end - begin, m_wText, IMESTR_MAXLEN);
	InsertString(m_wText, wstrLen);
	if(ms_pEvent)
		ms_pEvent->OnUpdate();
}

// PORT: 40250 reads the keyboard layout's default ANSI code page (GetLocaleInfoA LOCALE_IDEFAULTANSICODEPAGE).
// The host's input locale is the client locale, so its code page (SetDefaultCodePage from locale.cfg) is used.
void CIME::CheckInputLocale()
{
	static UINT s_uPrevCodePage = 0xFFFF;

	ms_uInputCodePage = GetDefaultCodePage();
	if ( s_uPrevCodePage == ms_uInputCodePage )
		return;
	s_uPrevCodePage = ms_uInputCodePage;

	ms_bVerticalCandidate = false;
	ms_wszCurrentIndicator = s_aszNonImeIndicator;

	if(ms_uOutputCodePage != 1256) {
		ms_uOutputCodePage = ms_uInputCodePage;
		Clear();
	}
}

// PORT: 40250 asks IMM whether an IME is open; there is none, so the state is IMEUI_STATE_OFF (0).
void CIME::CheckToggleState()
{
	CheckInputLocale();
	ms_bChineseIME = false;
	ms_dwImeState = 0;
}

/*---------------------------------------------------------------------------*/ /* Private */
void CIME::InsertString(wchar_t* wString, int iSize)
{
	if (IsMax(wString, iSize))
		return;

	if (ms_curpos < ms_lastpos)
		memmove(m_wText+ms_curpos+iSize, m_wText+ms_curpos, sizeof(wchar_t)*(ms_lastpos-ms_curpos));

	memcpy(m_wText+ms_curpos, wString, sizeof(wchar_t)*iSize);

	ms_curpos += iSize;
	ms_lastpos += iSize;
}

void CIME::OnChar(wchar_t c)
{
	if (m_bOnlyNumberMode)
		if (!iswdigit(c))
			return;

	if (!__IsWritable(c))
		return;

	InsertString(&c, 1);
}

// PORT: 40250 maps a keyboard-layout LANGID to its ANSI code page. Only CheckInputLocale's code page is used
// here (see there), so this answers with it.
UINT CIME::GetCodePageFromLang(LANGID)
{
	return GetDefaultCodePage();
}

// PORT: the IMM composition/candidate/reading processors (40250 IME.cpp:951-1227). No IMM context exists.
void CIME::ResultProcess(HIMC) {}
void CIME::CompositionProcessBuilding(HIMC) {}
void CIME::CompositionProcess(HIMC) {}
void CIME::AttributeProcess(HIMC) {}
void CIME::CandidateProcess(HIMC) {}
void CIME::ReadingProcess(HIMC) {}

bool CIME::IsMax(const wchar_t* wInput, int len)
{
	if (ms_lastpos + len > IMESTR_MAXLEN)
		return true;

	int textLen = WideCharToMultiByte(ms_uOutputCodePage, 0, m_wText, ms_lastpos, 0, 0, NULL, NULL);
	int inputLen = WideCharToMultiByte(ms_uOutputCodePage, 0, wInput, len, 0, 0, NULL, NULL);
	//return textLen + inputLen > m_max;

	if (textLen + inputLen > m_max)
		return true;
	else if (m_userMax != 0 && m_max != m_userMax)
	{
		std::wstring str = GetTextTagOutputString(m_wText, ms_lastpos);
		std::wstring input = GetTextTagOutputString(wInput, len);
		int textLen = WideCharToMultiByte(ms_uOutputCodePage, 0, str.c_str(), str.length(), 0, 0, NULL, NULL);
		int inputLen = WideCharToMultiByte(ms_uOutputCodePage, 0, input.c_str(), input.length(), 0, 0, NULL, NULL);
		return textLen + inputLen > m_userMax;
	}
	return false;
}

// PORT: 40250 identifies the CHT/CHS IME DLL version and the reading-window orientation. No IME DLL here.
DWORD CIME::GetImeId(UINT)
{
	return 0;
}

bool CIME::GetReadingWindowOrientation()
{
	return true;
}

void CIME::SetupImeApi()
{
	_GetReadingString = NULL;
	_ShowReadingWindow = NULL;
}

decltype(CIME::_ImmLockIMC) CIME::_ImmLockIMC{};

decltype(CIME::_ImmUnlockIMC) CIME::_ImmUnlockIMC{};

decltype(CIME::_ImmLockIMCC) CIME::_ImmLockIMCC{};

decltype(CIME::_ImmUnlockIMCC) CIME::_ImmUnlockIMCC{};

decltype(CIME::_GetReadingString) CIME::_GetReadingString{};

decltype(CIME::_ShowReadingWindow) CIME::_ShowReadingWindow{};

decltype(CIME::ms_bInitialized) CIME::ms_bInitialized{};

decltype(CIME::ms_bDisableIMECompletely) CIME::ms_bDisableIMECompletely{};

decltype(CIME::ms_bUILessMode) CIME::ms_bUILessMode{};

decltype(CIME::ms_bImeEnabled) CIME::ms_bImeEnabled{};

decltype(CIME::ms_bCaptureInput) CIME::ms_bCaptureInput{};

decltype(CIME::ms_bChineseIME) CIME::ms_bChineseIME{};

decltype(CIME::ms_bUseIMMCandidate) CIME::ms_bUseIMMCandidate{};

decltype(CIME::ms_hWnd) CIME::ms_hWnd{};

decltype(CIME::ms_hklCurrent) CIME::ms_hklCurrent{};

decltype(CIME::ms_szKeyboardLayout) CIME::ms_szKeyboardLayout{};

decltype(CIME::ms_stOSVI) CIME::ms_stOSVI{};

decltype(CIME::ms_hImm32Dll) CIME::ms_hImm32Dll{};

decltype(CIME::ms_hCurrentImeDll) CIME::ms_hCurrentImeDll{};

decltype(CIME::ms_dwImeState) CIME::ms_dwImeState{};

decltype(CIME::ms_adwId) CIME::ms_adwId{};

decltype(CIME::ms_dwIMELevel) CIME::ms_dwIMELevel{};

decltype(CIME::ms_dwIMELevelSaved) CIME::ms_dwIMELevelSaved{};

decltype(CIME::ms_bCandidateList) CIME::ms_bCandidateList{};

decltype(CIME::ms_dwCandidateCount) CIME::ms_dwCandidateCount{};

decltype(CIME::ms_bVerticalCandidate) CIME::ms_bVerticalCandidate{};

decltype(CIME::ms_iCandListIndexBase) CIME::ms_iCandListIndexBase{};

decltype(CIME::ms_wszCandidate) CIME::ms_wszCandidate{};

decltype(CIME::ms_dwCandidateSelection) CIME::ms_dwCandidateSelection{};

decltype(CIME::ms_dwCandidatePageSize) CIME::ms_dwCandidatePageSize{};

decltype(CIME::ms_bReadingInformation) CIME::ms_bReadingInformation{};

decltype(CIME::ms_iReadingError) CIME::ms_iReadingError{};

decltype(CIME::ms_bHorizontalReading) CIME::ms_bHorizontalReading{};

decltype(CIME::ms_wstrReading) CIME::ms_wstrReading{};

decltype(CIME::ms_wszCurrentIndicator) CIME::ms_wszCurrentIndicator{};

decltype(CIME::ms_pEvent) CIME::ms_pEvent{};

decltype(CIME::m_wText) CIME::m_wText{};

decltype(CIME::ms_compLen) CIME::ms_compLen{};

decltype(CIME::ms_curpos) CIME::ms_curpos{};

decltype(CIME::ms_lastpos) CIME::ms_lastpos{};

decltype(CIME::ms_ulbegin) CIME::ms_ulbegin{};

decltype(CIME::ms_ulend) CIME::ms_ulend{};

decltype(CIME::ms_uOutputCodePage) CIME::ms_uOutputCodePage{};

decltype(CIME::ms_uInputCodePage) CIME::ms_uInputCodePage{};