#include "FluFrameless.h"

#include <QQuickWindow>
#include <QGuiApplication>
#include <QScreen>

#ifdef Q_OS_WIN
#pragma comment (lib,"user32.lib")
#pragma comment (lib,"dwmapi.lib")
#include <windows.h>
#include <windowsx.h>
#include <dwmapi.h>
static inline QByteArray qtNativeEventType()
{
    static const auto result = "windows_generic_MSG";
    return result;
}
static inline bool isCompositionEnabled(){
    typedef HRESULT (WINAPI* DwmIsCompositionEnabledPtr)(BOOL *pfEnabled);
    HMODULE module = ::LoadLibraryW(L"dwmapi.dll");
    if (module)
    {
        BOOL composition_enabled = false;
        DwmIsCompositionEnabledPtr dwm_is_composition_enabled;
        dwm_is_composition_enabled= reinterpret_cast<DwmIsCompositionEnabledPtr>(::GetProcAddress(module, "DwmIsCompositionEnabled"));
        if (dwm_is_composition_enabled)
        {
            dwm_is_composition_enabled(&composition_enabled);
        }
        return composition_enabled;
    }
    return false;
}
#endif

FluFrameless::FluFrameless(QQuickItem *parent)
    : QQuickItem{parent}
{
    appbar(nullptr);
    maximizeButton(nullptr);
    minimizedButton(nullptr);
    closeButton(nullptr);
    topmost(false);
    disabled(false);
}

FluFrameless::~FluFrameless(){
    qApp->removeNativeEventFilter(this);
}

void FluFrameless::componentComplete(){
    if(_disabled){
        return;
    }
    _current = window()->winId();
    window()->setFlags(( window()->flags()) | Qt::CustomizeWindowHint | Qt::WindowMinimizeButtonHint | Qt::WindowCloseButtonHint | Qt::FramelessWindowHint);
    if(!_fixSize){
        window()->setFlag(Qt::WindowMaximizeButtonHint);
    }
    window()->installEventFilter(this);
    qApp->installNativeEventFilter(this);
    if(_appbar){
        _appbar->installEventFilter(this);
    }
    if(_maximizeButton){
        setHitTestVisible(_maximizeButton);
    }
    if(_minimizedButton){
        setHitTestVisible(_minimizedButton);
    }
    if(_closeButton){
        setHitTestVisible(_closeButton);
    }
#ifdef Q_OS_WIN
    HWND hwnd = reinterpret_cast<HWND>(window()->winId());
    DWORD style = ::GetWindowLongPtr(hwnd, GWL_STYLE);
    if(_fixSize){
        ::SetWindowLongPtr(hwnd, GWL_STYLE, style | WS_THICKFRAME);
        for (int i = 0; i < qApp->screens().count(); ++i) {
            connect( qApp->screens().at(i),&QScreen::logicalDotsPerInchChanged,this,[=]{
                SetWindowPos(hwnd,nullptr,0,0,0,0,SWP_NOZORDER | SWP_NOOWNERZORDER | SWP_NOMOVE | SWP_FRAMECHANGED);
            });
        }
    }else{
        ::SetWindowLongPtr(hwnd, GWL_STYLE, style | WS_MAXIMIZEBOX | WS_THICKFRAME);
    }
    SetWindowPos(hwnd,nullptr,0,0,0,0,SWP_NOZORDER | SWP_NOOWNERZORDER | SWP_NOMOVE | SWP_NOSIZE | SWP_FRAMECHANGED);
    connect(window(),&QQuickWindow::screenChanged,this,[hwnd]{
        ::SetWindowPos(hwnd,0,0,0,0,0,SWP_NOMOVE | SWP_NOSIZE | SWP_NOZORDER | SWP_FRAMECHANGED | SWP_NOOWNERZORDER);
        ::RedrawWindow(hwnd, NULL, NULL, RDW_INVALIDATE | RDW_UPDATENOW);
    });
#endif
    connect(this,&FluFrameless::topmostChanged,this,[this]{
        _setWindowTopmost(topmost());
    });
    _setWindowTopmost(topmost());
}

bool FluFrameless::nativeEventFilter(const QByteArray &eventType, void *message, QT_NATIVE_EVENT_RESULT_TYPE *result){
#ifdef Q_OS_WIN
    if ((eventType != qtNativeEventType()) || !message) {
        return false;
    }
    const auto msg = static_cast<const MSG *>(message);
    const HWND hwnd = msg->hwnd;
    if (!hwnd || !msg) {
        return false;
    }
    const qint64 wid = reinterpret_cast<qint64>(hwnd);
    if(wid != _current){
        return false;
    }
    const UINT uMsg = msg->message;
    const WPARAM wParam = msg->wParam;
    const LPARAM lParam = msg->lParam;
    static QPoint offsetXY;
    if(uMsg == WM_WINDOWPOSCHANGING){
        WINDOWPOS* wp = reinterpret_cast<WINDOWPOS*>(lParam);
        if (wp != nullptr && (wp->flags & SWP_NOSIZE) == 0)
        {
            wp->flags |= SWP_NOCOPYBITS;
            *result = ::DefWindowProcW(hwnd, uMsg, wParam, lParam);
            return true;
        }
        return false;
    }else if(uMsg == WM_NCCALCSIZE){
        const auto clientRect = ((wParam == FALSE) ? reinterpret_cast<LPRECT>(lParam) : &(reinterpret_cast<LPNCCALCSIZE_PARAMS>(lParam))->rgrc[0]);
        const LONG originalTop = clientRect->top;
        const LONG originalLeft = clientRect->left;
        const LONG originalRight = clientRect->right;
        const LONG originalBottom = clientRect->bottom;
        const LRESULT hitTestResult = ::DefWindowProcW(hwnd, WM_NCCALCSIZE, wParam, lParam);
        if ((hitTestResult != HTERROR) && (hitTestResult != HTNOWHERE)) {
            *result = hitTestResult;
            return true;
        }
        int offsetSize = 0;
        bool isMaximum = ::IsZoomed(hwnd);
        offsetXY = QPoint(abs(clientRect->left - originalLeft),abs(clientRect->top - originalTop));
        if(isMaximum || _isFullScreen()){
            offsetSize = 0;
        }else{
            offsetSize = 1;
        }
        if(!isCompositionEnabled()){
            offsetSize = 0;
        }
        if (!isMaximum || QT_VERSION >= QT_VERSION_CHECK(6, 0, 0)) {
            clientRect->top = originalTop + offsetSize;
            clientRect->bottom = originalBottom - offsetSize;
            clientRect->left = originalLeft + offsetSize;
            clientRect->right = originalRight - offsetSize;
        }
        *result = WVR_REDRAW;
        return true;
    }else if(uMsg == WM_NCHITTEST){
        if(_hitMaximizeButton()){
            if (*result == HTNOWHERE) {
                *result = HTZOOM;
            }
            return true;
        }
        *result = 0;
        POINT nativeGlobalPos{GET_X_LPARAM(lParam), GET_Y_LPARAM(lParam)};
        POINT nativeLocalPos = nativeGlobalPos;
        ::ScreenToClient(hwnd, &nativeLocalPos);
        RECT clientRect{0, 0, 0, 0};
        ::GetClientRect(hwnd, &clientRect);
        auto clientWidth = clientRect.right-clientRect.left;
        auto clientHeight = clientRect.bottom-clientRect.top;
        bool left = nativeLocalPos.x < _margins;
        bool right = nativeLocalPos.x > clientWidth - _margins;
        bool top = nativeLocalPos.y < _margins;
        bool bottom = nativeLocalPos.y > clientHeight - _margins;
        *result = 0;
        if (!_fixSize && !_isFullScreen() && !_isMaximized()) {
            if (left && top) {
                *result = HTTOPLEFT;
            } else if (left && bottom) {
                *result = HTBOTTOMLEFT;
            } else if (right && top) {
                *result = HTTOPRIGHT;
            } else if (right && bottom) {
                *result = HTBOTTOMRIGHT;
            } else if (left) {
                *result = HTLEFT;
            } else if (right) {
                *result = HTRIGHT;
            } else if (top) {
                *result = HTTOP;
            } else if (bottom) {
                *result = HTBOTTOM;
            }
        }
        if (0 != *result) {
            return true;
        }
        auto aa = _hitAppBar();
        if(aa){
            *result = HTCAPTION;
            return true;
        }
        *result = HTCLIENT;
        return true;
    }else if(uMsg == WM_NCLBUTTONDBLCLK || uMsg == WM_NCLBUTTONDOWN){
        if(_hitMaximizeButton()){
            QMouseEvent event = QMouseEvent(QEvent::MouseButtonPress, QPoint(), QPoint(), Qt::LeftButton, Qt::LeftButton, Qt::NoModifier);
            QGuiApplication::sendEvent(_maximizeButton,&event);
            return true;
        }
    }else if(uMsg == WM_NCLBUTTONUP || uMsg == WM_NCRBUTTONUP){
        if(_hitMaximizeButton()){
            QMouseEvent event = QMouseEvent(QEvent::MouseButtonRelease, QPoint(), QPoint(), Qt::LeftButton, Qt::LeftButton, Qt::NoModifier);
            QGuiApplication::sendEvent(_maximizeButton,&event);
            return true;
        }
    }else if(uMsg == WM_NCPAINT){
        *result = FALSE;
        return true;
    }else if(uMsg == WM_NCACTIVATE){
        *result = ::DefWindowProcW(hwnd, WM_NCACTIVATE, wParam, -1);
        return true;
    }else if(uMsg == WM_GETMINMAXINFO){
        MINMAXINFO* minmaxInfo = reinterpret_cast<MINMAXINFO *>(lParam);
#if QT_VERSION >= QT_VERSION_CHECK(6,0,0)
        minmaxInfo->ptMaxPosition.x = 0;
        minmaxInfo->ptMaxPosition.y = 0;
        minmaxInfo->ptMaxSize.x = 0;
        minmaxInfo->ptMaxSize.y = 0;
#else
        auto pixelRatio = window()->devicePixelRatio();
        auto geometry = window()->screen()->availableGeometry();
        RECT rect;
        SystemParametersInfo(SPI_GETWORKAREA, 0, &rect, 0);
        minmaxInfo->ptMaxPosition.x = rect.left - offsetXY.x();
        minmaxInfo->ptMaxPosition.y = rect.top - offsetXY.x();
        minmaxInfo->ptMaxSize.x = geometry.width()*pixelRatio + offsetXY.x() * 2;
        minmaxInfo->ptMaxSize.y = geometry.height()*pixelRatio + offsetXY.y() * 2;
#endif
        return false;
    }else if(uMsg == WM_NCRBUTTONDOWN){
        if (wParam == HTCAPTION) {
            _showSystemMenu(QCursor::pos());
        }
    }else if(uMsg == WM_KEYDOWN || uMsg == WM_SYSKEYDOWN){
        const bool altPressed = ((wParam == VK_MENU) || (::GetKeyState(VK_MENU) < 0));
        const bool spacePressed = ((wParam == VK_SPACE) || (::GetKeyState(VK_SPACE) < 0));
        if (altPressed && spacePressed) {
            auto pos = window()->position();
            _showSystemMenu(QPoint(pos.x(),pos.y()+_appbar->height()));
        }
    }else if(uMsg == WM_SYSCOMMAND){
        if(wParam == SC_MINIMIZE){
            if(window()->transientParent()){
                window()->transientParent()->showMinimized();
            }else{
                window()->showMinimized();
            }
            return true;
        }
        return false;
    }
    return false;
#endif
    return false;
}

bool FluFrameless::_isMaximized(){
    return window()->visibility() == QWindow::Maximized;
}

bool FluFrameless::_isFullScreen(){
    return window()->visibility() == QWindow::FullScreen;
}

void FluFrameless::_showSystemMenu(QPoint point){
#ifdef Q_OS_WIN
    HWND hwnd = reinterpret_cast<HWND>(window()->winId());
    DWORD style = ::GetWindowLongPtr(hwnd,GWL_STYLE);
    ::SetWindowLongPtr(hwnd, GWL_STYLE, style | WS_SYSMENU);
    const HMENU hMenu = ::GetSystemMenu(hwnd, FALSE);
    if(_isMaximized() || _isFullScreen()){
        ::EnableMenuItem(hMenu,SC_MOVE,MFS_DISABLED);
        ::EnableMenuItem(hMenu,SC_RESTORE,MFS_ENABLED);
    }else{
        ::EnableMenuItem(hMenu,SC_MOVE,MFS_ENABLED);
        ::EnableMenuItem(hMenu,SC_RESTORE,MFS_DISABLED);
    }
    if(!_fixSize && !_isMaximized() && !_isFullScreen()){
        ::EnableMenuItem(hMenu,SC_SIZE,MFS_ENABLED);
        ::EnableMenuItem(hMenu,SC_MAXIMIZE,MFS_ENABLED);
    }else{
        ::EnableMenuItem(hMenu,SC_SIZE,MFS_DISABLED);
        ::EnableMenuItem(hMenu,SC_MAXIMIZE,MFS_DISABLED);
    }
    const int result = ::TrackPopupMenu(hMenu, (TPM_RETURNCMD | (QGuiApplication::isRightToLeft() ? TPM_RIGHTALIGN : TPM_LEFTALIGN)), point.x()*window()->devicePixelRatio(), point.y()*window()->devicePixelRatio(), 0, hwnd, nullptr);
    if (result != FALSE) {
        ::PostMessageW(hwnd, WM_SYSCOMMAND, result, 0);
    }
    ::SetWindowLongPtr(hwnd, GWL_STYLE, style &~ WS_SYSMENU);
#endif
}

bool FluFrameless::_containsCursorToItem(QQuickItem* item){
    if(!item || !item->isVisible()){
        return false;
    }
    auto point = QCursor::pos();
    auto rect =  QRectF(item->mapToGlobal(QPoint(0,0)),item->size());
    if(point.x()>rect.x() && point.x()<(rect.x()+rect.width()) && point.y()>rect.y() && point.y()<(rect.y()+rect.height())){
        return true;
    }
    return false;
}

bool FluFrameless::_hitAppBar(){
    foreach (auto item, _hitTestList) {
        if(_containsCursorToItem(item)){
            return false;
        }
    }
    if(_containsCursorToItem(_appbar)){
        return true;
    }
    return false;
}

bool FluFrameless::_hitMaximizeButton(){
    if(_containsCursorToItem(_maximizeButton)){
        return true;
    }
    return false;
}

void FluFrameless::_updateCursor(int edges){
    switch (edges) {
    case 0:
        window()->setCursor(Qt::ArrowCursor);
        break;
    case Qt::LeftEdge:
    case Qt::RightEdge:
        window()->setCursor(Qt::SizeHorCursor);
        break;
    case Qt::TopEdge:
    case Qt::BottomEdge:
        window()->setCursor(Qt::SizeVerCursor);
        break;
    case Qt::LeftEdge | Qt::TopEdge:
    case Qt::RightEdge | Qt::BottomEdge:
        window()->setCursor(Qt::SizeFDiagCursor);
        break;
    case Qt::RightEdge | Qt::TopEdge:
    case Qt::LeftEdge | Qt::BottomEdge:
        window()->setCursor(Qt::SizeBDiagCursor);
        break;
    }
}

void FluFrameless::showFullScreen(){
    window()->showFullScreen();
}

void FluFrameless::showMaximized(){
#ifdef Q_OS_WIN
    HWND hwnd = reinterpret_cast<HWND>(window()->winId());
    ::ShowWindow(hwnd,3);
#else
    window()->showMaximized();
#endif
}

void FluFrameless::showMinimized(){
    window()->showMinimized();
}

void FluFrameless::showNormal(){
    window()->showNormal();
}

void FluFrameless::setHitTestVisible(QQuickItem* val){
    _hitTestList.append(val);
}


void FluFrameless::_setWindowTopmost(bool topmost){
#ifdef Q_OS_WIN
    HWND hwnd = reinterpret_cast<HWND>(window()->winId());
    if(topmost){
        ::SetWindowPos(hwnd, HWND_TOPMOST, 0, 0, 0, 0, SWP_NOMOVE | SWP_NOSIZE);
    }else{
        ::SetWindowPos(hwnd, HWND_NOTOPMOST, 0, 0, 0, 0, SWP_NOMOVE | SWP_NOSIZE);
    }
#else
    window()->setFlag(Qt::WindowStaysOnTopHint,topmost);
#endif
}

bool FluFrameless::eventFilter(QObject *obj, QEvent *ev){
#ifndef Q_OS_WIN
    switch (ev->type()) {
    case QEvent::MouseButtonPress:
        if(_edges!=0){
            QMouseEvent *event = static_cast<QMouseEvent*>(ev);
            if(event->button() == Qt::LeftButton){
                _updateCursor(_edges);
                window()->startSystemResize(Qt::Edges(_edges));
            }
        }else{
            if(_hitAppBar()){
                window()->startSystemMove();
            }
        }
        break;
    case QEvent::MouseButtonRelease:
        _edges = 0;
        break;
    case QEvent::MouseMove: {
        if(_isMaximized() || _isFullScreen()){
            break;
        }
        if(_fixSize){
            break;
        }
        QMouseEvent *event = static_cast<QMouseEvent*>(ev);
        QPoint p =
#if QT_VERSION < QT_VERSION_CHECK(6,0,0)
            event->pos();
#else
            event->position().toPoint();
#endif
        if(p.x() >= _margins && p.x() <= (window()->width() - _margins) && p.y() >= _margins && p.y() <= (window()->height() - _margins)){
            if(_edges != 0){
                _edges = 0;
                _updateCursor(_edges);
            }
            break;
        }
        _edges = 0;
        if ( p.x() < _margins ) {
            _edges |= Qt::LeftEdge;
        }
        if ( p.x() > (window()->width() - _margins) ) {
            _edges |= Qt::RightEdge;
        }
        if ( p.y() < _margins ) {
            _edges |= Qt::TopEdge;
        }
        if ( p.y() > (window()->height() - _margins) ) {
            _edges |= Qt::BottomEdge;
        }
        _updateCursor(_edges);
        break;
    }
    default:
        break;
    }
#endif
    return QObject::eventFilter(obj, ev);
}