// This script is a modified version of Thomas Malloch's "Focus Last Active Window on Other Monitor", last modified Sep 14, 2016.
// The original script can be found here:
//     https://www.displayfusion.com/ScriptedFunctions/View/?ID=feb3f25b-de43-40d3-bddc-23a13bdde7bb
//
// The following items have been changed
//     - IsDisplayFusionWindowOrHiddenExplorerWindow now stores "BFS.Window.GetClass(window)" into a string, whereas it was executed in each IF check
//     - The typo "visable" was corrected to "visible"
//     - "using System.Drawing;" has been removed because it is not used.
//     
// Modification by wolfreak99

using System;
using System.Collections.Generic;
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 visible windows
	//use a dictionary for quick access. wish .NET 2 had a hashset
	Dictionary<IntPtr, int> visibleWindows = new Dictionary<IntPtr, int>();
	foreach(IntPtr window in BFS.Window.GetVisibleWindowHandles())
		visibleWindows.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 visible window, continue
            if (!visibleWindows.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
        string windowClass = BFS.Window.GetClass(window);
        if ((windowClass.StartsWith("DF", StringComparison.OrdinalIgnoreCase)) ||
            (windowClass.Equals("EdgeUiInputTopWndClass", StringComparison.OrdinalIgnoreCase)) ||
            (windowClass.Equals("EdgeUiInputWndClass", StringComparison.OrdinalIgnoreCase)) ||
            (windowClass.Equals("NativeHWNDHost", StringComparison.OrdinalIgnoreCase)) ||
            (windowClass.Equals("ModeInputWnd", StringComparison.OrdinalIgnoreCase)) ||
            (windowClass.Equals("MetroGhostWindow", StringComparison.OrdinalIgnoreCase)) ||
            (windowClass.Equals("ImmersiveLauncher", StringComparison.OrdinalIgnoreCase)) ||
            (windowClass.Equals("ApplicationManager_ImmersiveShellWindow", StringComparison.OrdinalIgnoreCase)) ||
            (windowClass.Equals("Shell_TrayWnd", StringComparison.OrdinalIgnoreCase)) ||
            (windowClass.Equals("WorkerW", StringComparison.OrdinalIgnoreCase)) ||
            (windowClass.Equals("Progman", StringComparison.OrdinalIgnoreCase)) ||
            (windowClass.Equals("SearchPane", StringComparison.OrdinalIgnoreCase))) {
            return true;
        }

        return false;
    }
}