// HDT plugin: makes the in-game overlay work under Wine/Proton on Hyprland.
//
// Wine's X11 driver decides per window whether it is "managed" (handed to the
// compositor, which tiles/floats/focuses it) or override-redirect (placed where
// the app says, stacked on top, left alone). A popup becomes managed for good
// once it is the active window during a show or SetWindowPos. WPF's Show()
// activates by default, so HDT's overlay ends up managed: Hyprland places it
// wherever it likes instead of over the game.
//
// Separately, Wine cuts every alpha-0 pixel of a layered window out of the X11
// shape, and XWayland shows those pixels as opaque black. Painting the window
// background at alpha 1/255 keeps every pixel inside the shape while staying
// invisible.
//
// Both fixes have to land before the overlay is first shown. HDT loads enabled
// plugins (plugins.xml) before it starts its overlay update loop, so OnLoad is
// early enough; enabling the plugin mid-session needs an HDT restart.
//
// Approach from alexzfe/hdt-omarchy (Utility/Wine.cs), done as a plugin so the
// official HDT build and its updater stay in place.

using System;
using System.Runtime.InteropServices;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Interop;
using System.Windows.Media;
using Hearthstone_Deck_Tracker;
using Hearthstone_Deck_Tracker.Plugins;
using Hearthstone_Deck_Tracker.Utility.Logging;

namespace HdtWineOverlay
{
	public class WineOverlayPlugin : IPlugin
	{
		public string Name => "Wine Overlay Fix";
		public string Description => "Transparent, correctly placed overlay under Wine/Proton (Wayland). Restart HDT after enabling.";
		public string ButtonText => "";
		public string Author => "fred";
		public Version Version => new Version(0, 1, 0);
		public MenuItem MenuItem => null;

		private HwndSource _hookedSource;
		private RECT _lastGameRect;
		private DateTime _nextPoll = DateTime.MinValue;

		public void OnLoad()
		{
			if(!IsWine())
			{
				Log.Info("Not running under Wine, nothing to do");
				return;
			}
			var overlay = Core.Overlay;
			var handle = new WindowInteropHelper(overlay).Handle;
			if(handle != IntPtr.Zero && overlay.IsVisible)
				Log.Warn("Overlay was already shown before this plugin loaded; restart HDT for the fix to apply");

			// Never activate on show: keeps Wine from making the overlay a managed window.
			overlay.ShowActivated = false;

			if(!(overlay.Background is SolidColorBrush { Color.A: > 0 }))
			{
				var brush = new SolidColorBrush(Color.FromArgb(1, 0, 0, 0));
				brush.Freeze();
				overlay.Background = brush;
			}

			if(handle != IntPtr.Zero)
				HookMouseActivate(handle);
			else
				overlay.SourceInitialized += OnOverlaySourceInitialized;

			Log.Info("Applied Wine overlay workarounds");
		}

		public void OnUnload()
		{
			Core.Overlay.SourceInitialized -= OnOverlaySourceInitialized;
			_hookedSource?.RemoveHook(WndProc);
			_hookedSource = null;
		}

		public void OnButtonPress()
		{
		}

		// Called by HDT every 100ms on the UI thread.
		public void OnUpdate()
		{
			if(_hookedSource == null || DateTime.UtcNow < _nextPoll)
				return;
			_nextPoll = DateTime.UtcNow.AddMilliseconds(250);

			// HDT follows the game window through an out-of-context WinEvent hook
			// (EVENT_OBJECT_LOCATIONCHANGE), which Wine doesn't deliver for
			// compositor-driven moves. Poll the game's client rect instead.
			var overlay = Core.Overlay;
			if(!overlay.IsContentVisible)
				return;
			var game = FindWindow("UnityWndClass", "Hearthstone");
			if(game == IntPtr.Zero || !GetClientRect(game, out var rect))
				return;
			var origin = new POINT();
			if(!ClientToScreen(game, ref origin))
				return;
			rect.Left += origin.X;
			rect.Right += origin.X;
			rect.Top += origin.Y;
			rect.Bottom += origin.Y;
			if(rect.Equals(_lastGameRect))
				return;
			_lastGameRect = rect;
			overlay.UpdatePosition();
		}

		private void OnOverlaySourceInitialized(object sender, EventArgs e)
			=> HookMouseActivate(new WindowInteropHelper(Core.Overlay).Handle);

		private void HookMouseActivate(IntPtr handle)
		{
			_hookedSource = HwndSource.FromHwnd(handle);
			_hookedSource?.AddHook(WndProc);
		}

		// Clicking an overlay button would otherwise activate the window, which
		// makes Wine turn it into a managed window on the next position update.
		private static IntPtr WndProc(IntPtr hwnd, int msg, IntPtr wParam, IntPtr lParam, ref bool handled)
		{
			const int wmMouseActivate = 0x0021;
			const int maNoActivate = 3;
			if(msg != wmMouseActivate)
				return IntPtr.Zero;
			handled = true;
			return new IntPtr(maNoActivate);
		}

		private static bool IsWine()
		{
			var ntdll = GetModuleHandle("ntdll.dll");
			return ntdll != IntPtr.Zero && GetProcAddress(ntdll, "wine_get_version") != IntPtr.Zero;
		}

		[StructLayout(LayoutKind.Sequential)]
		private struct RECT
		{
			public int Left, Top, Right, Bottom;
		}

		[StructLayout(LayoutKind.Sequential)]
		private struct POINT
		{
			public int X, Y;
		}

		[DllImport("kernel32.dll", CharSet = CharSet.Ansi)]
		private static extern IntPtr GetModuleHandle(string lpModuleName);

		[DllImport("kernel32.dll", CharSet = CharSet.Ansi)]
		private static extern IntPtr GetProcAddress(IntPtr hModule, string lpProcName);

		[DllImport("user32.dll", CharSet = CharSet.Unicode)]
		private static extern IntPtr FindWindow(string lpClassName, string lpWindowName);

		[DllImport("user32.dll")]
		private static extern bool GetClientRect(IntPtr hWnd, out RECT lpRect);

		[DllImport("user32.dll")]
		private static extern bool ClientToScreen(IntPtr hWnd, ref POINT lpPoint);
	}
}