/*
 *  Copyright 2019-2021 Diligent Graphics LLC
 *  Copyright 2015-2019 Egor Yusov
 *  
 *  Licensed under the Apache License, Version 2.0 (the "License");
 *  you may not use this file except in compliance with the License.
 *  You may obtain a copy of the License at
 *  
 *      http://www.apache.org/licenses/LICENSE-2.0
 *  
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 *
 *  In no event and under no legal theory, whether in tort (including negligence), 
 *  contract, or otherwise, unless required by applicable law (such as deliberate 
 *  and grossly negligent acts) or agreed to in writing, shall any Contributor be
 *  liable for any damages, including any direct, indirect, special, incidental, 
 *  or consequential damages of any character arising as a result of this License or 
 *  out of the use or inability to use the software (including but not limited to damages 
 *  for loss of goodwill, work stoppage, computer failure or malfunction, or any and 
 *  all other commercial damages or losses), even if such Contributor has been advised 
 *  of the possibility of such damages.
 */

#ifndef NOMINMAX
#    define NOMINMAX
#endif
#include <Windows.h>

#include "GraphicsTypes.h"
#include "imgui.h"
#include "ImGuiImplWin32.hpp"
#include "backends/imgui_impl_win32.h"
#include "DebugUtilities.hpp"

IMGUI_IMPL_API LRESULT ImGui_ImplWin32_WndProcHandler(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam);

namespace Diligent
{

ImGuiImplWin32::ImGuiImplWin32(HWND           hWnd,
                               IRenderDevice* pDevice,
                               TEXTURE_FORMAT BackBufferFmt,
                               TEXTURE_FORMAT DepthBufferFmt,
                               Uint32         InitialVertexBufferSize,
                               Uint32         InitialIndexBufferSize) :
    ImGuiImplDiligent{pDevice, BackBufferFmt, DepthBufferFmt, InitialVertexBufferSize, InitialIndexBufferSize}
{
    ImGui_ImplWin32_Init(hWnd);
}

ImGuiImplWin32::~ImGuiImplWin32()
{
    ImGui_ImplWin32_Shutdown();
}

void ImGuiImplWin32::NewFrame(Uint32 RenderSurfaceWidth, Uint32 RenderSurfaceHeight, SURFACE_TRANSFORM SurfacePreTransform)
{
    VERIFY(SurfacePreTransform == SURFACE_TRANSFORM_IDENTITY, "Unexpected surface pre-transform");

    ImGui_ImplWin32_NewFrame();
    ImGuiImplDiligent::NewFrame(RenderSurfaceWidth, RenderSurfaceHeight, SurfacePreTransform);

#ifdef DILIGENT_DEBUG
    {
        ImGuiIO& io = ImGui::GetIO();
        VERIFY(io.DisplaySize.x == 0 || io.DisplaySize.x == static_cast<float>(RenderSurfaceWidth),
               "Render surface width (", RenderSurfaceWidth, ") does not match io.DisplaySize.x (", io.DisplaySize.x, ")");
        VERIFY(io.DisplaySize.y == 0 || io.DisplaySize.y == static_cast<float>(RenderSurfaceHeight),
               "Render surface height (", RenderSurfaceHeight, ") does not match io.DisplaySize.y (", io.DisplaySize.y, ")");
    }
#endif
}

// Allow compilation with old Windows SDK. MinGW doesn't have default _WIN32_WINNT/WINVER versions.
#ifndef WM_MOUSEWHEEL
#    define WM_MOUSEWHEEL 0x020A
#endif
#ifndef WM_MOUSEHWHEEL
#    define WM_MOUSEHWHEEL 0x020E
#endif

LRESULT ImGuiImplWin32::Win32_ProcHandler(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam)
{
    if (ImGui::GetCurrentContext() == NULL)
        return 0;

    auto res = ImGui_ImplWin32_WndProcHandler(hwnd, msg, wParam, lParam);

    ImGuiIO& io = ImGui::GetIO();
    switch (msg)
    {
        case WM_LBUTTONDOWN:
        case WM_LBUTTONDBLCLK:
        case WM_RBUTTONDOWN:
        case WM_RBUTTONDBLCLK:
        case WM_MBUTTONDOWN:
        case WM_MBUTTONDBLCLK:
        case WM_XBUTTONDOWN:
        case WM_XBUTTONDBLCLK:
        case WM_LBUTTONUP:
        case WM_RBUTTONUP:
        case WM_MBUTTONUP:
        case WM_XBUTTONUP:
        case WM_MOUSEWHEEL:
        case WM_MOUSEHWHEEL:
            return io.WantCaptureMouse ? 1 : 0;

        case WM_KEYDOWN:
        case WM_SYSKEYDOWN:
        case WM_KEYUP:
        case WM_SYSKEYUP:
        case WM_CHAR:
            return io.WantCaptureKeyboard ? 1 : 0;
        case WM_SETCURSOR:
            return res;
    }

    return res;
}

} // namespace Diligent