using System.Runtime.InteropServices;
using Avalonia.Controls;

namespace CVRManager.Views;

public static class WindowIcons
{
    const uint WM_SETICON = 0x0080;
    const int ICON_SMALL = 0;
    const int ICON_BIG = 1;
    const int SM_CXICON = 11;
    const int SM_CXSMICON = 49;

    [DllImport("user32.dll", CharSet = CharSet.Unicode)]
    static extern uint PrivateExtractIcons(string file, int index, int cx, int cy, IntPtr[] icons, uint[] ids, uint count, uint flags);

    [DllImport("user32.dll")]
    static extern IntPtr SendMessage(IntPtr hwnd, uint msg, IntPtr wParam, IntPtr lParam);

    [DllImport("user32.dll")]
    static extern int GetSystemMetrics(int index);

    public static void Apply(Window window)
    {
        if (!OperatingSystem.IsWindows()) return;
        var exe = Environment.ProcessPath;
        var hwnd = window.TryGetPlatformHandle()?.Handle ?? IntPtr.Zero;
        if (exe == null || hwnd == IntPtr.Zero || !Path.GetFileName(exe).Equals("CVRManager.exe", StringComparison.OrdinalIgnoreCase)) return;

        Set(hwnd, exe, GetSystemMetrics(SM_CXSMICON), ICON_SMALL);
        Set(hwnd, exe, GetSystemMetrics(SM_CXICON), ICON_BIG);
    }

    static void Set(IntPtr hwnd, string exe, int size, int kind)
    {
        var handles = new IntPtr[1];
        var ids = new uint[1];
        if (PrivateExtractIcons(exe, 0, size, size, handles, ids, 1, 0) > 0 && handles[0] != IntPtr.Zero)
            SendMessage(hwnd, WM_SETICON, (IntPtr)kind, handles[0]);
    }
}