// TortoiseSVN - a Windows shell extension for easy version control

// Copyright (C) 2008, 2010, 2021 - TortoiseSVN

// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public License
// as published by the Free Software Foundation; either version 2
// of the License, or (at your option) any later version.

// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.

// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software Foundation,
// 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
//
#pragma once
#include <mlang.h>

// these functions are taken from an article of the 'old new thing' blog:
// http://blogs.msdn.com/oldnewthing/archive/2004/07/16/185261.aspx

inline HRESULT textOutFl(HDC hdc, int x, int y, LPCWSTR psz, int cch)
{
    ATL::CComPtr<IMLangFontLink2> pfl;
    HRESULT                       hr = pfl.CoCreateInstance(CLSID_CMultiLanguage, nullptr, CLSCTX_ALL);
    if (FAILED(hr))
        return hr;

    HFONT hfOrig = static_cast<HFONT>(GetCurrentObject(hdc, OBJ_FONT));
    POINT ptOrig;
    DWORD dwAlignOrig = GetTextAlign(hdc);
    if (!(dwAlignOrig & TA_UPDATECP))
    {
        SetTextAlign(hdc, dwAlignOrig | TA_UPDATECP);
    }
    MoveToEx(hdc, x, y, &ptOrig);
    DWORD dwFontCodePages = 0;
    hr                    = pfl->GetFontCodePages(hdc, hfOrig, &dwFontCodePages);
    if (SUCCEEDED(hr))
    {
        while (cch > 0)
        {
            DWORD dwActualCodePages;
            long  cchActual;
            hr = pfl->GetStrCodePages(psz, cch, dwFontCodePages, &dwActualCodePages, &cchActual);
            if (FAILED(hr))
            {
                break;
            }

            if (dwActualCodePages & dwFontCodePages)
            {
                TextOut(hdc, 0, 0, psz, cchActual);
            }
            else
            {
                HFONT hfLinked;
                if (FAILED(hr = pfl->MapFont(hdc, dwActualCodePages, 0, &hfLinked)))
                {
                    break;
                }
                SelectObject(hdc, static_cast<HGDIOBJ>(hfLinked));
                TextOut(hdc, 0, 0, psz, cchActual);
                SelectObject(hdc, static_cast<HGDIOBJ>(hfOrig));
                pfl->ReleaseFont(hfLinked);
            }
            psz += cchActual;
            cch -= cchActual;
        }
        if (FAILED(hr))
        {
            //  We started outputting characters so we have to finish.
            //  Do the rest without font linking since we have no choice.
            TextOut(hdc, 0, 0, psz, cch);
            hr = S_FALSE;
        }
    }

    pfl.Release();

    if (!(dwAlignOrig & TA_UPDATECP))
    {
        SetTextAlign(hdc, dwAlignOrig);
        MoveToEx(hdc, ptOrig.x, ptOrig.y, nullptr);
    }

    return hr;
}

inline void textOutTryFl(HDC hdc, int x, int y, LPCWSTR psz, int cch)
{
    if (FAILED(textOutFl(hdc, x, y, psz, cch)))
    {
        TextOut(hdc, x, y, psz, cch);
    }
}