// ==WindhawkMod==
// @id              desktop-marquee-fade-v26
// @name            Desktop Marquee Fade (Async)
// @description     Add a smooth, modern fade effect to your desktop selection
// @version         26.0.1
// @author          angel_lov
// @include         explorer.exe
// @compilerOptions -luser32 -lgdi32
// ==/WindhawkMod==

#define NOMINMAX
#include <windows.h>
#include <windhawk_api.h>
#include <thread>
#include <commctrl.h>

#pragma comment(lib, "user32.lib")
#pragma comment(lib, "gdi32.lib")
#pragma comment(lib, "comctl32.lib")

HWND g_hOverlayWnd = NULL;
HHOOK g_hMouseHook = NULL;
POINT g_dragStart = { 0 };
bool g_isDragging = false;


HBRUSH g_hBrush = NULL;
HPEN g_hPen = NULL;

#define START_ALPHA 60

LRESULT CALLBACK OverlayWndProc(HWND hwnd, UINT msg, WPARAM wParam, LPARAM lParam) {
    static int s_alpha = 0;

    switch (msg) {
        case WM_USER + 1: {
            KillTimer(hwnd, 1);
            RECT* prc = (RECT*)lParam;

            SetWindowPos(hwnd, HWND_TOPMOST, prc->left, prc->top,
                         prc->right - prc->left, prc->bottom - prc->top,
                         SWP_NOACTIVATE | SWP_NOCOPYBITS | SWP_NOREDRAW);

            ShowWindow(hwnd, SW_SHOWNA);
            s_alpha = START_ALPHA;
            SetLayeredWindowAttributes(hwnd, 0, (BYTE)s_alpha, LWA_ALPHA);

            RedrawWindow(hwnd, NULL, NULL, RDW_INVALIDATE | RDW_UPDATENOW);

            delete prc;
            SetTimer(hwnd, 1, 30, NULL);
            return 0;
        }
        case WM_TIMER: {
            s_alpha -= 8;
            if (s_alpha <= 0) {
                KillTimer(hwnd, 1);
                s_alpha = 0;
                ShowWindow(hwnd, SW_HIDE);
            } else {
                SetLayeredWindowAttributes(hwnd, 0, (BYTE)s_alpha, LWA_ALPHA);
            }
            return 0;
        }
        case WM_PAINT: {
            PAINTSTRUCT ps;
            HDC hdc = BeginPaint(hwnd, &ps);
            RECT rc;
            GetClientRect(hwnd, &rc);

            int radius = 4;

            HBRUSH hOldBrush = (HBRUSH)SelectObject(hdc, g_hBrush);
            HPEN hOldPen = (HPEN)SelectObject(hdc, g_hPen);

            RoundRect(hdc, 0, 0, rc.right, rc.bottom, radius, radius);

            SelectObject(hdc, hOldPen);
            SelectObject(hdc, hOldBrush);

            EndPaint(hwnd, &ps);
            return 0;
        }
        case WM_ERASEBKGND: return 1;
    }
    return DefWindowProc(hwnd, msg, wParam, lParam);
}

LRESULT CALLBACK MouseHookProc(int nCode, WPARAM wParam, LPARAM lParam) {
    if (nCode == HC_ACTION) {
        MSLLHOOKSTRUCT* pMouse = (MSLLHOOKSTRUCT*)lParam;

        if (wParam == WM_LBUTTONDOWN) {
            HWND hWndUnder = WindowFromPoint(pMouse->pt);
            wchar_t className[256];
            GetClassNameW(hWndUnder, className, 256);

            if (wcscmp(className, L"SysListView32") == 0) {

                LVHITTESTINFO hit = {0};
                hit.pt = pMouse->pt;
                ScreenToClient(hWndUnder, &hit.pt);

                int nItem = (int)SendMessageW(hWndUnder, LVM_HITTEST, 0, (LPARAM)&hit);

                if (nItem == -1) { // hit on empty space
                    g_dragStart = pMouse->pt;
                    g_isDragging = true;
                } else {
                    g_isDragging = false; // hit on icon
                }
            } else {
                g_isDragging = false;
            }
        }
        else if (wParam == WM_LBUTTONUP && g_isDragging) {
            g_isDragging = false;

            int w = (pMouse->pt.x > g_dragStart.x ? pMouse->pt.x - g_dragStart.x : g_dragStart.x - pMouse->pt.x);
            int h = (pMouse->pt.y > g_dragStart.y ? pMouse->pt.y - g_dragStart.y : g_dragStart.y - pMouse->pt.y);

            if (w > 10 && h > 10) {
                int left = (g_dragStart.x < pMouse->pt.x ? g_dragStart.x : pMouse->pt.x);
                int top = (g_dragStart.y < pMouse->pt.y ? g_dragStart.y : pMouse->pt.y);

                RECT* prc = new RECT{ left, top, left + w, top + h };
                PostMessageW(g_hOverlayWnd, WM_USER + 1, 0, (LPARAM)prc);
            }
        }
    }
    return CallNextHookEx(g_hMouseHook, nCode, wParam, lParam);
}

BOOL Wh_ModInit() {
    std::thread([]() {
        g_hBrush = CreateSolidBrush(GetSysColor(COLOR_HIGHLIGHT));
        g_hPen = CreatePen(PS_SOLID, 1, GetSysColor(COLOR_HIGHLIGHT));

        WNDCLASSW wc = {0};
        wc.lpfnWndProc = OverlayWndProc;
        wc.hInstance = GetModuleHandle(NULL);
        wc.lpszClassName = L"FadeMarqueeClass";
        wc.hbrBackground = (HBRUSH)GetStockObject(NULL_BRUSH);
        RegisterClassW(&wc);

        g_hOverlayWnd = CreateWindowExW(WS_EX_LAYERED | WS_EX_TRANSPARENT | WS_EX_TOOLWINDOW | WS_EX_TOPMOST | WS_EX_NOACTIVATE,
            wc.lpszClassName, NULL, WS_POPUP, 0, 0, 0, 0, NULL, NULL, wc.hInstance, NULL);

        ShowWindow(g_hOverlayWnd, SW_HIDE);

        g_hMouseHook = SetWindowsHookExW(WH_MOUSE_LL, MouseHookProc, GetModuleHandle(NULL), 0);
        MSG msg;
        while (GetMessage(&msg, NULL, 0, 0)) DispatchMessage(&msg);

        if (g_hMouseHook) UnhookWindowsHookEx(g_hMouseHook);
    }).detach();
    return TRUE;
}

void Wh_ModUninit() {
    PostMessageW(g_hOverlayWnd, WM_QUIT, 0, 0);
    if (g_hBrush) DeleteObject(g_hBrush);
    if (g_hPen) DeleteObject(g_hPen);
}