using System;
using System.Collections.Generic;
using System.Drawing;
using System.Runtime.InteropServices;

// The 'windowHandle' parameter will contain the window handle for the:
//   - Active window when run by hotkey
//   - Window Location target when run by a Window Location rule
//   - TitleBar Button owner when run by a TitleBar Button
//   - Jump List owner when run from a Taskbar Jump List
//   - Currently focused window if none of these match
public static class DisplayFusionFunction
{
	[DllImport("user32.dll", SetLastError = true)]
	static extern IntPtr GetWindow(IntPtr hWnd, uint uCmd);
	const uint GW_HWNDNEXT = 2;

	public static void Run(IntPtr windowHandle)
	{	
		//all visable windows
		//use a dictionary for quick access. wish .NET 2 had a hashset
		Dictionary<IntPtr, int> visableWindows = new Dictionary<IntPtr, int>();
		foreach(IntPtr window in BFS.Window.GetVisibleWindowHandles())
			visableWindows.Add(window, 0);
		
		//get the monitor id that the current window is in
		uint currentMonitorId = BFS.Monitor.GetMonitorIDByWindow(windowHandle);
		
		//enumerate through all windows, starting with the focused window, and moving down
		for(IntPtr window = windowHandle; window != IntPtr.Zero; window = GetWindow(window, GW_HWNDNEXT))
		{		
			//if it isn't a visable window, continue
			if(!visableWindows.ContainsKey(window))
				continue;
			
			//check if it's a displayfusion or hidden explorer window. if so, skip it.
			//this will avoid adding titlebar button and other things
			if(IsDisplayFusionWindowOrHiddenExplorerWindow(window))
				continue;
				
			//get the monitor this window is in. if the window are in the same monitor, ignore it
			if(BFS.Monitor.GetMonitorIDByWindow(window) == currentMonitorId)
                continue;
			
			//if we got this far, that means this window is the topmost window on the other window. switch to it
			BFS.Window.Focus(window);
			break;
		}
	}
	
	private static bool IsDisplayFusionWindowOrHiddenExplorerWindow(IntPtr window)
	{
        //ignore any DisplayFusion windows (title bar buttons, etc.)
        //ignore pesky hidden explorer.exe windows
        if((BFS.Window.GetClass(window).StartsWith("DF", StringComparison.OrdinalIgnoreCase)) ||
            (BFS.Window.GetClass(window).Equals("EdgeUiInputTopWndClass", StringComparison.OrdinalIgnoreCase)) ||
            (BFS.Window.GetClass(window).Equals("EdgeUiInputWndClass", StringComparison.OrdinalIgnoreCase)) ||
            (BFS.Window.GetClass(window).Equals("NativeHWNDHost", StringComparison.OrdinalIgnoreCase)) ||
            (BFS.Window.GetClass(window).Equals("ModeInputWnd", StringComparison.OrdinalIgnoreCase)) ||
            (BFS.Window.GetClass(window).Equals("MetroGhostWindow", StringComparison.OrdinalIgnoreCase)) ||
            (BFS.Window.GetClass(window).Equals("ImmersiveLauncher", StringComparison.OrdinalIgnoreCase)) ||
            (BFS.Window.GetClass(window).Equals("ApplicationManager_ImmersiveShellWindow", StringComparison.OrdinalIgnoreCase)) ||
            (BFS.Window.GetClass(window).Equals("Shell_TrayWnd", StringComparison.OrdinalIgnoreCase)) ||
            (BFS.Window.GetClass(window).Equals("WorkerW", StringComparison.OrdinalIgnoreCase)) ||
            (BFS.Window.GetClass(window).Equals("Progman", StringComparison.OrdinalIgnoreCase)) ||
            (BFS.Window.GetClass(window).Equals("SearchPane", StringComparison.OrdinalIgnoreCase)))
        {
            return true;
        }
        
        return false;
	}
}