/*

 * Copyright (c) 2016, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * This code 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

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 */

#include "systemScale.h"

#include <d2d1.h>

#include <jdk_util.h>

#ifndef MDT_EFFECTIVE_DPI

#define MDT_EFFECTIVE_DPI 0

#endif

void GetScreenDpi(HMONITOR hmon, float *dpiX, float *dpiY)

{

    unsigned x = 0;

    unsigned y = 0;

    // for debug purposes

    static float scale = -2.0f;

    if (scale == -2) {

        scale = -1;

        char *uiScale = getenv("J2D_UISCALE");

        if (uiScale != NULL) {

            scale = (float)strtod(uiScale, NULL);

            if (errno == ERANGE || scale <= 0) {

                scale = -1;

            }

        }

    }

    if (scale > 0) {

        *dpiX = *dpiY = scale;

        return;

    }

    typedef HRESULT(WINAPI D2D1CreateFactoryFunc)

                   (D2D1_FACTORY_TYPE, REFIID,

                    CONST D2D1_FACTORY_OPTIONS*, ID2D1Factory**);

    typedef HRESULT(WINAPI GetDpiForMonitorFunc)(HMONITOR, int, UINT*, UINT*);

    static HMODULE hLibSHCoreDll = NULL;

    static GetDpiForMonitorFunc *lpGetDpiForMonitor = NULL;

    if (hLibSHCoreDll == NULL) {

        hLibSHCoreDll = JDK_LoadSystemLibrary("shcore.dll");

        if (hLibSHCoreDll != NULL) {

            lpGetDpiForMonitor = (GetDpiForMonitorFunc*)GetProcAddress(

                hLibSHCoreDll, "GetDpiForMonitor");

        }

    }

    if (lpGetDpiForMonitor != NULL) {

        HRESULT hResult = lpGetDpiForMonitor(hmon,

                                             MDT_EFFECTIVE_DPI, &x, &y);

        if (hResult == S_OK) {

            *dpiX = static_cast<float>(x);

            *dpiY = static_cast<float>(y);

        }

    } else {

        static HMODULE d2dDll = NULL;

        static BOOL loadAttempted = FALSE;

        static D2D1CreateFactoryFunc *lpD2D1CreateFactory = NULL;

        if (!loadAttempted && d2dDll == NULL) {

            loadAttempted = TRUE;

            d2dDll = JDK_LoadSystemLibrary("d2d1.dll");

        }

        if (d2dDll != NULL && lpD2D1CreateFactory == NULL) {

            lpD2D1CreateFactory = (D2D1CreateFactoryFunc*)GetProcAddress(

                    d2dDll, "D2D1CreateFactory");

        }

        if (lpD2D1CreateFactory != NULL) {

            ID2D1Factory* m_pDirect2dFactory;

            HRESULT res = lpD2D1CreateFactory

                          (D2D1_FACTORY_TYPE_SINGLE_THREADED,

                           __uuidof(ID2D1Factory), NULL,

                           &m_pDirect2dFactory);

            if (res == S_OK) {

           // m_pDirect2dFactory->GetDesktopDpi(dpiX, dpiY);

                m_pDirect2dFactory->Release();

            }

        }

    }

    return;

}

HMONITOR WINAPI getPrimaryMonitor()

{

    const POINT point = { 0, 0 };

    return MonitorFromPoint(point, MONITOR_DEFAULTTOPRIMARY);

}