using System;
using System.Drawing;
using System.Windows.Forms;
using System.Threading;
using System.Collections.Generic;

// 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
{
	private static readonly string SettingName = "DimMonitor_TransparentForm_Running";
	public static void Run(IntPtr windowHandle)
	{
		//toggle the setting from running to not running, and vice versa
		ToggleSetting();
		
		//check to see if we should exit
		bool isExiting = !IsTransparentWindowRunning();
				
		//if we are exiting, exit
		if(isExiting)
			return;
			
		//add all but the primary monitor to the list of monitors that will be dimmed
		List<Form> forms = new List<Form>();
		foreach(uint id in BFS.Monitor.GetMonitorIDs())
		{
			if(BFS.Monitor.GetMonitorBoundsByID(id).Equals(Screen.PrimaryScreen.Bounds))
				continue;
			
			forms.Add(new TransparentForm(id, 30m));
		}
		
		//this will open the forms we added to the list by using our custom application context
		Application.Run(new MultipleFormApplicationContext(forms));
	}
	
	//this function toggles the script settings from running to not running
	private static void ToggleSetting()
	{
		string status = BFS.ScriptSettings.ReadValue(SettingName);
		if(status.Equals("running", StringComparison.Ordinal))
			BFS.ScriptSettings.WriteValue(SettingName, "not");
		else
			BFS.ScriptSettings.WriteValue(SettingName, "running");
	}
	
	//this function allows us to see the currect state of the script
	private static bool IsTransparentWindowRunning()
	{
		string status = BFS.ScriptSettings.ReadValue(SettingName);
		return status.Equals("running", StringComparison.Ordinal);
	}
	
	//extend the ApplicationContext class to support opening multiple forms
	private class MultipleFormApplicationContext : ApplicationContext 
	{
		internal MultipleFormApplicationContext(List<Form> forms)
		{
			//open each of the forms, and add our closing event to them
			foreach(Form form in forms)
			{
				form.FormClosed += OnFormClosed;
				form.Show();	
			}		
		}
		
		//when all the forms close, make sure to exit the application
		private void OnFormClosed(object sender, EventArgs e)
		{
			if(Application.OpenForms.Count == 0)
				ExitThread();
		}
	}
	
	//extend the Form class to get the behavior we want
	private class TransparentForm : Form 
	{
		//this will tell us what monitor to open on
		private uint MonitorId;
		
		//this will tell us what transparency to use
		private decimal Transparency;
		
		//the contructor for our class
		internal TransparentForm(uint monitorId, decimal transparency)
		{		
			this.MonitorId = monitorId;
			this.Transparency = transparency;
			
			this.SuspendLayout();
			
			//setup the layout of this form
			this.BackColor = Color.Black;
			this.FormBorderStyle = FormBorderStyle.None;
			this.ShowInTaskbar = false;
			
			//setup the form load event
			this.Load += Form_Load;			
			
			this.ResumeLayout(false);
		}
		
		private void Form_Load(object sender, EventArgs e)
		{
			//set the window to be always on top
			BFS.Window.SetAlwaysOnTop(this.Handle, true);
			
			//make the window transparent
			BFS.Window.SetTransparency(this.Handle, this.Transparency);
			
			//add a windows style to the current style that will
			//tell this window to ignore user input
			uint style = (uint)BFS.Window.GetWindowStyleEx(this.Handle);
			BFS.Window.SetWindowStyleEx((BFS.WindowEnum.WindowStyleEx)(style | (uint)BFS.WindowEnum.WindowStyleEx.WS_EX_TRANSPARENT | (uint)BFS.WindowEnum.WindowStyleEx.WS_EX_LAYERED), this.Handle);
		
			//move the window to the desired monitor
			this.Bounds = BFS.Monitor.GetMonitorBoundsByID(this.MonitorId);
			
			//start up a thread to listen for an exit event
			new Thread(new ThreadStart(ExitListener)).Start();
		}
		
		private void ExitListener()
		{
			while(true)
			{
				//if we should close, tell the main thread to close the form
				if(!IsTransparentWindowRunning())
				{
					try
					{
						this.Invoke((MethodInvoker) delegate
						{
							this.Close();
						});
					}
					catch //something went wrong, ignore
					{
					}
						
					break;
				}
				
				//sleep for a quarter of a second
				BFS.General.ThreadWait(250);
			}
		}
	}
}