// Copyright (c) 2016-2020 Kiwano - Nomango
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.

#include <kiwano/platform/Window.h>

#if defined(KGE_PLATFORM_WINDOWS)

#include <memory>
#include <array>
#include <kiwano/platform/Keys.h>
#include <kiwano/utils/Logger.h>
#include <kiwano/event/Events.h>
#include <kiwano/platform/Application.h>
#include <kiwano/platform/FileSystem.h>
#include <kiwano/render/Renderer.h>
#include <Windowsx.h>  // GET_X_LPARAM, GET_Y_LPARAM
#include <imm.h>       // ImmAssociateContext
#pragma comment(lib, "imm32.lib")
#include <timeapi.h>  // timeBeginPeriod, timeEndPeriod
#pragma comment(lib, "winmm.lib")

namespace kiwano
{

KGE_DECLARE_SMART_PTR(WindowWin32Impl);

class KGE_API WindowWin32Impl : public Window
{
public:
    WindowWin32Impl();

    virtual ~WindowWin32Impl();

    void Init(const WindowConfig& config);

    void SetTitle(const String& title) override;

    void SetIcon(Icon icon) override;

    void SetMinimumSize(uint32_t width, uint32_t height) override;

    void SetMaximumSize(uint32_t width, uint32_t height) override;

    void SetCursor(CursorType cursor) override;

    void SetResolution(uint32_t width, uint32_t height, bool fullscreen) override;

    Vector<Resolution> GetResolutions() override;

    void PumpEvents() override;

    void SetImmEnabled(bool enable) override;

    DWORD GetStyle() const;

    void SetActive(bool active);

    void UpdateCursor();

    LRESULT MessageProc(HWND, UINT32, WPARAM, LPARAM);

    static LRESULT CALLBACK StaticWndProc(HWND, UINT32, WPARAM, LPARAM);

private:
    bool       resizable_;
    bool       is_moving_or_resizing_;
    bool       is_minimized_;
    CursorType mouse_cursor_;
    HIMC       imc_restore_;
    int        mouse_flag_;
    String     device_name_;

    Vector<Resolution>       resolutions_;
    std::array<KeyCode, 256> key_map_;
};

WindowPtr Window::Create(const WindowConfig& config)
{
    WindowWin32ImplPtr ptr = MakePtr<WindowWin32Impl>();
    if (ptr)
    {
        ptr->Init(config);
    }
    return ptr;
}

}  // namespace kiwano

namespace kiwano
{

#define WINDOW_FIXED_STYLE WS_OVERLAPPED | WS_CAPTION | WS_SYSMENU | WS_MINIMIZEBOX
#define WINDOW_RESIZABLE_STYLE WS_OVERLAPPED | WS_CAPTION | WS_SYSMENU | WS_MINIMIZEBOX | WS_SIZEBOX | WS_MAXIMIZEBOX
#define WINDOW_FULLSCREEN_STYLE WS_CLIPCHILDREN | WS_POPUP

namespace
{
MONITORINFOEXA GetMoniterInfoEx(HWND hwnd)
{
    HMONITOR       monitor = ::MonitorFromWindow(hwnd, MONITOR_DEFAULTTONEAREST);
    MONITORINFOEXA monitor_info;

    memset(&monitor_info, 0, sizeof(monitor_info));
    monitor_info.cbSize = sizeof(monitor_info);
    ::GetMonitorInfoA(monitor, &monitor_info);

    return monitor_info;
}

void AdjustWindow(uint32_t width, uint32_t height, DWORD style, uint32_t* win_width, uint32_t* win_height)
{
    RECT rc;
    ::SetRect(&rc, 0, 0, (int)width, (int)height);
    ::AdjustWindowRect(&rc, style, false);

    *win_width  = rc.right - rc.left;
    *win_height = rc.bottom - rc.top;

    MONITORINFOEXA info = GetMoniterInfoEx(NULL);

    uint32_t screenw = info.rcWork.right - info.rcWork.left;
    uint32_t screenh = info.rcWork.bottom - info.rcWork.top;

    if (*win_width > screenw)
        *win_width = screenw;
    if (*win_height > screenh)
        *win_height = screenh;
}

HICON Icon2HIcon(const Icon& icon)
{
    HICON hicon = NULL;
    if (icon.resource_id != 0 && IS_INTRESOURCE(icon.resource_id))
    {
        HINSTANCE hinstance = ::GetModuleHandle(nullptr);

        hicon = (HICON)::LoadImage(hinstance, MAKEINTRESOURCE(icon.resource_id), IMAGE_ICON, 0, 0,
                                   LR_DEFAULTCOLOR | LR_CREATEDIBSECTION | LR_DEFAULTSIZE);
    }
    else
    {
        String full_path = FileSystem::GetInstance().GetFullPathForFile(icon.file_path);
        if (!full_path.empty())
        {
            hicon = (HICON)::LoadImageA(NULL, full_path.c_str(), IMAGE_ICON, 0, 0,
                                        LR_DEFAULTCOLOR | LR_CREATEDIBSECTION | LR_DEFAULTSIZE | LR_LOADFROMFILE);
        }
    }
    return hicon;
}

}  // namespace

WindowWin32Impl::WindowWin32Impl()
    : resizable_(false)
    , is_moving_or_resizing_(false)
    , is_minimized_(false)
    , mouse_cursor_(CursorType::Arrow)
    , key_map_{}
    , imc_restore_(nullptr)
    , mouse_flag_{}
{
    // Keys
    key_map_[VK_UP]      = KeyCode::Up;
    key_map_[VK_LEFT]    = KeyCode::Left;
    key_map_[VK_RIGHT]   = KeyCode::Right;
    key_map_[VK_DOWN]    = KeyCode::Down;
    key_map_[VK_RETURN]  = KeyCode::Enter;
    key_map_[VK_SPACE]   = KeyCode::Space;
    key_map_[VK_ESCAPE]  = KeyCode::Esc;
    key_map_[VK_CONTROL] = KeyCode::Ctrl;
    key_map_[VK_SHIFT]   = KeyCode::Shift;
    key_map_[VK_MENU]    = KeyCode::Alt;
    key_map_[VK_TAB]     = KeyCode::Tab;
    key_map_[VK_DELETE]  = KeyCode::Delete;
    key_map_[VK_BACK]    = KeyCode::Back;

    // VK_L* and VK_R*
    key_map_[VK_LCONTROL] = KeyCode::Ctrl;
    key_map_[VK_RCONTROL] = KeyCode::Ctrl;
    key_map_[VK_LSHIFT]   = KeyCode::Shift;
    key_map_[VK_RSHIFT]   = KeyCode::Shift;
    key_map_[VK_LMENU]    = KeyCode::Alt;
    key_map_[VK_RMENU]    = KeyCode::Alt;
    key_map_[VK_LWIN]     = KeyCode::Super;
    key_map_[VK_RWIN]     = KeyCode::Super;

    // A - Z
    for (size_t i = 0, size = ('Z' - 'A'); i <= size; ++i)
        key_map_['A' + i] = KeyCode(size_t(KeyCode::A) + i);

    // Num 0 - 9
    for (size_t i = 0; i < 10; ++i)
        key_map_['0' + i] = KeyCode(size_t(KeyCode::Num0) + i);

    // Numpad 0 - 9
    for (size_t i = 0; i < 10; ++i)
        key_map_[VK_NUMPAD0 + i] = KeyCode(size_t(KeyCode::Numpad0) + i);

    // F1 - F12
    for (size_t i = 0; i < 12; ++i)
        key_map_[VK_F1 + i] = KeyCode(size_t(KeyCode::F1) + i);

    ::timeBeginPeriod(0);
}

WindowWin32Impl::~WindowWin32Impl()
{
    if (handle_)
    {
        ::DestroyWindow(handle_);
        handle_ = nullptr;
    }

    ::timeEndPeriod(0);
}

void WindowWin32Impl::Init(const WindowConfig& config)
{
    HINSTANCE   hinst  = GetModuleHandle(nullptr);
    WNDCLASSEXA wcex   = { 0 };
    wcex.cbSize        = sizeof(WNDCLASSEX);
    wcex.lpszClassName = "KiwanoAppWnd";
    wcex.style         = CS_HREDRAW | CS_VREDRAW /* | CS_DBLCLKS */;
    wcex.lpfnWndProc   = WindowWin32Impl::StaticWndProc;
    wcex.hIcon         = Icon2HIcon(config.icon);
    wcex.cbClsExtra    = 0;
    wcex.cbWndExtra    = sizeof(LONG_PTR);
    wcex.hInstance     = hinst;
    wcex.hbrBackground = (HBRUSH)::GetStockObject(BLACK_BRUSH);
    wcex.lpszMenuName  = nullptr;
    wcex.hCursor       = ::LoadCursor(hinst, IDC_ARROW);

    ::RegisterClassExA(&wcex);

    // Get the nearest monitor to this window
    HMONITOR monitor = ::MonitorFromPoint(POINT{ 0, 0 }, MONITOR_DEFAULTTOPRIMARY);

    // Get the target monitor info
    MONITORINFOEXA monitor_info;
    memset(&monitor_info, 0, sizeof(MONITORINFOEXA));
    monitor_info.cbSize = sizeof(MONITORINFOEXA);
    ::GetMonitorInfoA(monitor, &monitor_info);

    // Save the device name
    device_name_ = monitor_info.szDevice;

    uint32_t screenw = monitor_info.rcWork.right - monitor_info.rcWork.left;
    uint32_t screenh = monitor_info.rcWork.bottom - monitor_info.rcWork.top;

    uint32_t win_width, win_height;
    AdjustWindow(config.width, config.height, GetStyle(), &win_width, &win_height);

    int left = monitor_info.rcWork.left + (screenw - win_width) / 2;
    int top  = monitor_info.rcWork.top + (screenh - win_height) / 2;

    width_         = win_width;
    height_        = win_height;
    resizable_     = config.resizable;
    is_fullscreen_ = config.fullscreen;

    handle_ = ::CreateWindowExA(0, "KiwanoAppWnd", config.title.c_str(), GetStyle(), left, top, width_, height_,
                                nullptr, nullptr, hinst, nullptr);

    if (handle_ == nullptr)
    {
        ::UnregisterClassA("KiwanoAppWnd", hinst);
        KGE_THROW_SYSTEM_ERROR(HRESULT_FROM_WIN32(GetLastError()), "Create window failed");
    }

    // disable imm
    SetImmEnabled(false);

    // use Application instance in message loop
    ::SetWindowLongPtrA(handle_, GWLP_USERDATA, LONG_PTR(this));

    ::ShowWindow(handle_, SW_SHOWNORMAL);
    ::UpdateWindow(handle_);

    if (is_fullscreen_)
    {
        MONITORINFOEXA info = GetMoniterInfoEx(handle_);

        int x  = (int)info.rcMonitor.left;
        int y  = (int)info.rcMonitor.top;
        int cx = (int)(info.rcMonitor.right - info.rcMonitor.left);
        int cy = (int)(info.rcMonitor.bottom - info.rcMonitor.top);

        // Top the window
        ::SetWindowPos(handle_, HWND_TOPMOST, x, y, cx, cy, SWP_NOACTIVATE);
        ::ShowWindow(handle_, SW_SHOWNORMAL);

        resolution_.width  = config.width;
        resolution_.height = config.height;
    }
    else
    {
        RECT client_area;
        ::GetClientRect(handle_, &client_area);
        resolution_.width  = uint32_t(client_area.right - client_area.left);
        resolution_.height = uint32_t(client_area.bottom - client_area.top);
    }
}

void WindowWin32Impl::PumpEvents()
{
    MSG msg;
    while (::PeekMessage(&msg, nullptr, 0, 0, PM_REMOVE))
    {
        ::TranslateMessage(&msg);
        ::DispatchMessage(&msg);
    }
}

void WindowWin32Impl::SetImmEnabled(bool enable)
{
    const bool enabled = imc_restore_ == nullptr;
    if (enable != enabled)
    {
        if (enable)
        {
            ::ImmAssociateContext(handle_, imc_restore_);
            imc_restore_ = nullptr;
        }
        else
        {
            imc_restore_ = ::ImmAssociateContext(handle_, nullptr);
        }
    }
}

void WindowWin32Impl::SetTitle(const String& title)
{
    KGE_ASSERT(handle_);
    ::SetWindowTextA(handle_, title.c_str());
}

void WindowWin32Impl::SetIcon(Icon icon)
{
    KGE_ASSERT(handle_);

    HICON hicon = Icon2HIcon(icon);
    ::SendMessage(handle_, WM_SETICON, ICON_BIG, (LPARAM)hicon);
    ::SendMessage(handle_, WM_SETICON, ICON_SMALL, (LPARAM)hicon);
}

void WindowWin32Impl::SetMinimumSize(uint32_t width, uint32_t height)
{
    AdjustWindow(width, height, GetStyle(), &min_width_, &min_height_);
}

void WindowWin32Impl::SetMaximumSize(uint32_t width, uint32_t height)
{
    AdjustWindow(width, height, GetStyle(), &max_width_, &max_height_);
}

void WindowWin32Impl::SetCursor(CursorType cursor)
{
    mouse_cursor_ = cursor;
}

void WindowWin32Impl::SetResolution(uint32_t width, uint32_t height, bool fullscreen)
{
    if (is_fullscreen_ != fullscreen)
    {
        is_fullscreen_ = fullscreen;

        // Reset window style
        ::SetWindowLongPtrA(handle_, GWL_STYLE, GetStyle());
    }

    if (is_fullscreen_)
    {
        MONITORINFOEXA info = GetMoniterInfoEx(handle_);
        int            x    = (int)info.rcMonitor.left;
        int            y    = (int)info.rcMonitor.top;
        int            cx   = (int)(info.rcMonitor.right - info.rcMonitor.left);
        int            cy   = (int)(info.rcMonitor.bottom - info.rcMonitor.top);

        // Top the window
        ::SetWindowPos(handle_, HWND_TOPMOST, x, y, cx, cy, SWP_NOACTIVATE);
        ::ShowWindow(handle_, SW_SHOWNORMAL);
    }
    else
    {
        // Adjust the rect of client area
        RECT rc = { 0, 0, LONG(width), LONG(height) };
        ::AdjustWindowRect(&rc, GetStyle(), false);

        width  = uint32_t(rc.right - rc.left);
        height = uint32_t(rc.bottom - rc.top);

        MONITORINFOEXA info    = GetMoniterInfoEx(handle_);
        uint32_t       screenw = uint32_t(info.rcWork.right - info.rcWork.left);
        uint32_t       screenh = uint32_t(info.rcWork.bottom - info.rcWork.top);
        int            left    = screenw > width ? ((screenw - width) / 2) : 0;
        int            top     = screenh > height ? ((screenh - height) / 2) : 0;

        // Reset window style
        ::SetWindowLongPtrA(handle_, GWL_STYLE, GetStyle());

        // Unpin the window
        ::SetWindowPos(handle_, HWND_NOTOPMOST, left, top, width, height, SWP_DRAWFRAME | SWP_FRAMECHANGED);
        ::ShowWindow(handle_, SW_SHOWNORMAL);
    }

    resolution_ = Resolution{ width, height, 0 };

    // Resize render target
    Renderer::GetInstance().Resize(width, height);
}

Vector<Resolution> WindowWin32Impl::GetResolutions()
{
    if (resolutions_.empty())
    {
        Set<String> resolution_list;

        DEVMODEA dmi;
        ZeroMemory(&dmi, sizeof(dmi));
        dmi.dmSize = sizeof(dmi);

        DWORD mode_count = 0;
        while (EnumDisplaySettingsA(device_name_.c_str(), mode_count++, &dmi) != 0)
        {
            StringStream ss;
            ss << dmi.dmPelsWidth << 'x' << dmi.dmPelsHeight << ':' << dmi.dmDisplayFrequency;

            if (resolution_list.find(ss.str()) == resolution_list.end())
            {
                resolution_list.insert(ss.str());
                resolutions_.push_back(Resolution{ uint32_t(dmi.dmPelsWidth), uint32_t(dmi.dmPelsHeight),
                                                   uint32_t(dmi.dmDisplayFrequency) });
            }
            ZeroMemory(&dmi, sizeof(dmi));
        }
    }
    return resolutions_;
}

DWORD WindowWin32Impl::GetStyle() const
{
    if (is_fullscreen_)
        return WINDOW_FULLSCREEN_STYLE;
    if (resizable_)
        return WINDOW_RESIZABLE_STYLE;
    return WINDOW_FIXED_STYLE;
}

void WindowWin32Impl::SetActive(bool active)
{
    if (!handle_)
        return;

    if (is_fullscreen_)
    {
        // Hide window when it is not active
        if (active)
        {
            ::SetWindowPos(handle_, HWND_TOPMOST, 0, 0, 0, 0, SWP_NOMOVE | SWP_NOSIZE | SWP_NOACTIVATE);
        }
        else
        {
            ::SetWindowPos(handle_, HWND_NOTOPMOST, 0, 0, 0, 0, SWP_NOMOVE | SWP_NOSIZE | SWP_NOACTIVATE);
        }
    }
}

void WindowWin32Impl::UpdateCursor()
{
    LPTSTR win32_cursor = IDC_ARROW;
    switch (mouse_cursor_)
    {
    case CursorType::Arrow:
        win32_cursor = IDC_ARROW;
        break;
    case CursorType::TextInput:
        win32_cursor = IDC_IBEAM;
        break;
    case CursorType::SizeAll:
        win32_cursor = IDC_SIZEALL;
        break;
    case CursorType::SizeWE:
        win32_cursor = IDC_SIZEWE;
        break;
    case CursorType::SizeNS:
        win32_cursor = IDC_SIZENS;
        break;
    case CursorType::SizeNESW:
        win32_cursor = IDC_SIZENESW;
        break;
    case CursorType::SizeNWSE:
        win32_cursor = IDC_SIZENWSE;
        break;
    case CursorType::Hand:
        win32_cursor = IDC_HAND;
        break;
    case CursorType::No:
        win32_cursor = IDC_NO;
        break;
    }
    ::SetCursor(::LoadCursor(nullptr, win32_cursor));
}

LRESULT WindowWin32Impl::MessageProc(HWND hwnd, UINT32 msg, WPARAM wparam, LPARAM lparam)
{
    switch (msg)
    {
    case WM_KEYDOWN:
    case WM_SYSKEYDOWN:
    {
        KeyCode key = this->key_map_[size_t(wparam)];
        if (key != KeyCode::Unknown)
        {
            KeyDownEventPtr evt = new KeyDownEvent;
            evt->code           = key;
            this->PushEvent(evt);
        }
    }
    break;

    case WM_KEYUP:
    case WM_SYSKEYUP:
    {
        KeyCode key = this->key_map_[size_t(wparam)];
        if (key != KeyCode::Unknown)
        {
            KeyUpEventPtr evt = new KeyUpEvent;
            evt->code         = key;
            this->PushEvent(evt);
        }
    }
    break;

    case WM_CHAR:
    {
        KeyCharEventPtr evt = new KeyCharEvent;
        evt->value          = char(wparam);
        this->PushEvent(evt);
    }
    break;

    case WM_IME_CHAR:
    {
        // no need to handle
        return TRUE;
    }

    case WM_IME_COMPOSITION:
    {
        if (lparam & GCS_RESULTSTR)
        {
            const auto hIMC = ::ImmGetContext(hwnd);
            if (hIMC)
            {
                // Get the size of the result string.
                auto dwSize = ::ImmGetCompositionStringA(hIMC, GCS_RESULTSTR, NULL, 0);

                // increase buffer size for terminating null character
                dwSize += sizeof(char);

                // Get the result strings that is generated by IME.
                String buf(size_t(dwSize), 0);
                ::ImmGetCompositionStringA(hIMC, GCS_RESULTSTR, const_cast<char*>(buf.data()), dwSize);
                ::ImmReleaseContext(hwnd, hIMC);

                IMEInputEventPtr evt = new IMEInputEvent;
                evt->value           = std::move(buf);
                this->PushEvent(evt);
                return TRUE;
            }
        }
    }

    case WM_LBUTTONDOWN:
    case WM_LBUTTONDBLCLK:
    case WM_RBUTTONDOWN:
    case WM_RBUTTONDBLCLK:
    case WM_MBUTTONDOWN:
    case WM_MBUTTONDBLCLK:
    {
        MouseDownEventPtr evt = new MouseDownEvent;
        evt->pos              = Point((float)GET_X_LPARAM(lparam), (float)GET_Y_LPARAM(lparam));

        if (msg == WM_LBUTTONDOWN || msg == WM_LBUTTONDBLCLK)
        {
            evt->button = MouseButton::Left;
        }
        else if (msg == WM_RBUTTONDOWN || msg == WM_RBUTTONDBLCLK)
        {
            evt->button = MouseButton::Right;
        }
        else if (msg == WM_MBUTTONDOWN || msg == WM_MBUTTONDBLCLK)
        {
            evt->button = MouseButton::Middle;
        }

        if (mouse_flag_ == 0 && ::GetCapture() == nullptr)
            ::SetCapture(hwnd);
        mouse_flag_ |= 1 << int(evt->button);

        this->PushEvent(evt);
    }
    break;

    case WM_LBUTTONUP:
    case WM_MBUTTONUP:
    case WM_RBUTTONUP:
    {
        MouseUpEventPtr evt = new MouseUpEvent;
        evt->pos            = Point((float)GET_X_LPARAM(lparam), (float)GET_Y_LPARAM(lparam));

        if (msg == WM_LBUTTONUP)
        {
            evt->button = MouseButton::Left;
        }
        else if (msg == WM_RBUTTONUP)
        {
            evt->button = MouseButton::Right;
        }
        else if (msg == WM_MBUTTONUP)
        {
            evt->button = MouseButton::Middle;
        }

        mouse_flag_ &= ~(1 << int(evt->button));
        if (mouse_flag_ == 0 && ::GetCapture() == hwnd)
            ::ReleaseCapture();

        this->PushEvent(evt);
    }
    break;

    case WM_MOUSEMOVE:
    {
        MouseMoveEventPtr evt = new MouseMoveEvent;
        evt->pos              = Point((float)GET_X_LPARAM(lparam), (float)GET_Y_LPARAM(lparam));
        this->PushEvent(evt);
    }
    break;

    case WM_MOUSEWHEEL:
    {
        MouseWheelEventPtr evt = new MouseWheelEvent;
        evt->pos               = Point((float)GET_X_LPARAM(lparam), (float)GET_Y_LPARAM(lparam));
        evt->wheel             = GET_WHEEL_DELTA_WPARAM(wparam) / (float)WHEEL_DELTA;
        this->PushEvent(evt);
    }
    break;

    case WM_SIZE:
    {
        bool resized = false;
        if (SIZE_MAXHIDE == wparam || SIZE_MINIMIZED == wparam)
        {
            KGE_DEBUG_LOGF("Window minimized");

            is_minimized_ = true;
            // Pause game when window is minimized
            Application::GetInstance().Pause();
        }
        else if (SIZE_MAXIMIZED == wparam)
        {
            KGE_DEBUG_LOGF("Window maximized");

            if (is_minimized_)
            {
                is_minimized_ = false;
                Application::GetInstance().Resume();
            }
            else
            {
                resized = true;
            }
        }
        else if (wparam == SIZE_RESTORED)
        {
            if (is_minimized_)
            {
                KGE_DEBUG_LOGF("Window restored");

                // the window was restored and was previously minimized
                is_minimized_ = false;
                Application::GetInstance().Resume();
            }
            else if (is_moving_or_resizing_)
            {
                // DO NOTHING until the dragging / resizing has stopped.
            }
            else
            {
                resized = true;
            }
        }
        if (resized)
        {
            this->width_  = ((uint32_t)(short)LOWORD(lparam));
            this->height_ = ((uint32_t)(short)HIWORD(lparam));

            WindowResizedEventPtr evt = new WindowResizedEvent;
            evt->window               = this;
            evt->width                = this->GetWidth();
            evt->height               = this->GetHeight();
            this->PushEvent(evt);

            KGE_DEBUG_LOGF("Window resized to (%d, %d)", this->width_, this->height_);
        }
    }
    break;

    case WM_ENTERSIZEMOVE:
    {
        is_moving_or_resizing_ = true;
        Application::GetInstance().Pause();
        return 0;
    }

    case WM_EXITSIZEMOVE:
    {
        is_moving_or_resizing_ = false;
        Application::GetInstance().Resume();

        // Send window resized event when client size changed
        RECT client_rect = { 0 };
        ::GetClientRect(hwnd, &client_rect);

        uint32_t client_width  = uint32_t(client_rect.right - client_rect.left);
        uint32_t client_height = uint32_t(client_rect.bottom - client_rect.top);
        if (client_width != this->GetWidth() || client_height != this->GetHeight())
        {
            KGE_DEBUG_LOGF("Window resized to (%d, %d)", client_width, client_height);

            this->width_  = client_width;
            this->height_ = client_height;

            WindowResizedEventPtr evt = new WindowResizedEvent;
            evt->window               = this;
            evt->width                = client_width;
            evt->height               = client_height;
            this->PushEvent(evt);
        }

        RECT window_rect = { 0 };
        ::GetWindowRect(hwnd, &window_rect);

        int window_x = int(window_rect.left);
        int window_y = int(window_rect.top);
        if (window_x != this->GetPosX() || window_y != this->GetPosY())
        {
            KGE_DEBUG_LOGF("Window moved to (%d, %d)", window_x, window_y);

            this->pos_x_ = window_x;
            this->pos_y_ = window_y;

            WindowMovedEventPtr evt = new WindowMovedEvent;
            evt->window             = this;
            evt->x                  = window_x;
            evt->y                  = window_y;
            this->PushEvent(evt);
        }
        return 0;
    }

    case WM_GETMINMAXINFO:
    {
        if (min_width_ && min_height_)
        {
            ((MINMAXINFO*)lparam)->ptMinTrackSize = POINT{ LONG(min_width_), LONG(min_height_) };
        }
        if (max_width_ && max_height_)
        {
            ((MINMAXINFO*)lparam)->ptMaxTrackSize = POINT{ LONG(max_width_), LONG(max_height_) };
            ((MINMAXINFO*)lparam)->ptMaxSize      = POINT{ LONG(max_width_), LONG(max_height_) };
        }
        return 0;
    }

    case WM_MOVE:
    {
        if (is_moving_or_resizing_)
        {
            // DO NOTHING until the dragging / resizing has stopped.
        }
        else
        {
            int window_x = GET_X_LPARAM(lparam);
            int window_y = GET_Y_LPARAM(lparam);

            KGE_DEBUG_LOGF("Window moved to (%d, %d)", window_x, window_y);

            this->pos_x_ = window_x;
            this->pos_y_ = window_y;

            WindowMovedEventPtr evt = new WindowMovedEvent;
            evt->window             = this;
            evt->x                  = window_x;
            evt->y                  = window_y;
            this->PushEvent(evt);
        }
    }
    break;

    case WM_MENUCHAR:
    {
        // Disables the crazy beeping sound when pressing a mnemonic key.
        // Simply tell Windows that we want the menu closed.
        return MAKELRESULT(0, MNC_CLOSE);
    }

    case WM_ACTIVATE:
    {
        bool active = (LOWORD(wparam) != WA_INACTIVE);

        WindowFocusChangedEventPtr evt = new WindowFocusChangedEvent;
        evt->window                    = this;
        evt->focus                     = active;
        this->PushEvent(evt);
    }
    break;

    case WM_SETFOCUS:
    {
        if (is_fullscreen_)
        {
            SetActive(true);
        }
    }
    break;

    case WM_KILLFOCUS:
    {
        if (is_fullscreen_)
        {
            SetActive(false);
        }
    }
    break;

    case WM_SETTEXT:
    {
        KGE_DEBUG_LOGF("Window title changed");

        this->title_ = strings::WideToNarrow(reinterpret_cast<LPCWSTR>(lparam));

        WindowTitleChangedEventPtr evt = new WindowTitleChangedEvent;
        evt->window                    = this;
        evt->title                     = this->title_;
        this->PushEvent(evt);
    }
    break;

    case WM_SETICON:
    {
        KGE_DEBUG_LOGF("Window icon changed");
    }
    break;

    case WM_DISPLAYCHANGE:
    {
        KGE_DEBUG_LOGF("The display resolution has changed");
    }
    break;

    case WM_SETCURSOR:
    {
        this->UpdateCursor();
    }
    break;

    case WM_CLOSE:
    {
        KGE_DEBUG_LOGF("Window is closing");

        WindowClosedEventPtr evt = new WindowClosedEvent;
        evt->window              = this;
        this->PushEvent(evt);
        this->SetShouldClose(true);
        return 0;
    }
    break;

    case WM_DESTROY:
    {
        KGE_DEBUG_LOGF("Window was destroyed");

        ::PostQuitMessage(0);
        return 0;
    }
    break;
    }

    return ::DefWindowProcA(hwnd, msg, wparam, lparam);
}

LRESULT CALLBACK WindowWin32Impl::StaticWndProc(HWND hwnd, UINT32 msg, WPARAM wparam, LPARAM lparam)
{
    LONG_PTR ptr = static_cast<LONG_PTR>(::GetWindowLongPtrA(hwnd, GWLP_USERDATA));
    if (ptr)
    {
        WindowWin32Impl* window = reinterpret_cast<WindowWin32Impl*>(ptr);
        return window->MessageProc(hwnd, msg, wparam, lparam);
    }
    return ::DefWindowProcA(hwnd, msg, wparam, lparam);
}

}  // namespace kiwano

#endif