using System;
using System.Drawing;

// The 'windowHandle' parameter will contain the window handle for the:
//   - Active window when run by hotkey
//   - Trigger target when run by a Trigger 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 const string LastMoveTimeSetting = "MoveWindowScript_LastMoveTime";
	private const string LastMonitorIdSetting = "MoveWindowScript_LastMonitorId";
	
	//this is the threshold to move windows, in milliseconds
	private const int MoveWindowThreshold = 5000;
	
	public static void Run(IntPtr windowHandle)
	{
		//these variables will hold the information about the last move
		DateTime lastMoveTime;
		uint lastMonitorId;
		
		//if we fail to get the settings, save the settings and exit the script
		if(!GetSettings(out lastMoveTime, out lastMonitorId))
		{
			SaveSettings(BFS.Monitor.GetMonitorIDByWindow(windowHandle));
			return;
		}
		
		//if the last time the script ran is longer than the threshold, save the settings and exit the script
		if(DateTime.UtcNow.Subtract(lastMoveTime) > new TimeSpan(0, 0, 0, 0, MoveWindowThreshold))
		{
			SaveSettings(BFS.Monitor.GetMonitorIDByWindow(windowHandle));
			return;
		}
		
		//find the last monitor ID in the list of connected monitors
		uint[] monitorIds = BFS.Monitor.GetMonitorIDs();
		int monitorIdIndex;
		for(monitorIdIndex = 0; monitorIdIndex < monitorIds.Length; monitorIdIndex++)
		{
			if(monitorIds[monitorIdIndex] != lastMonitorId)
				continue;
				
			break;
		}
		
		//get the next monitor ID
		uint nextMonitorID = monitorIds[++monitorIdIndex % monitorIds.Length];
		
		//move the window to the selected monitor
		BFS.Window.MoveToMonitor(nextMonitorID, windowHandle);
		
		//save the settings
		SaveSettings(nextMonitorID);
	}
	
	//this function will get the script settings
	private static bool GetSettings(out DateTime lastMoveTime, out uint lastMonitorId)
	{
		lastMoveTime = DateTime.MinValue;
		lastMonitorId = 0;
		long lastMoveTicks;
		if(!long.TryParse(BFS.ScriptSettings.ReadValue(LastMoveTimeSetting), out lastMoveTicks))
			return false;
			
		if(!uint.TryParse(BFS.ScriptSettings.ReadValue(LastMonitorIdSetting), out lastMonitorId))
			return false;
			
		lastMoveTime = new DateTime(lastMoveTicks);
		return true;
	}
	
	//this function will save the script settings
	private static void SaveSettings(uint lastMonitorId)
	{
		BFS.ScriptSettings.WriteValue(LastMoveTimeSetting, "" + DateTime.UtcNow.Ticks);
		BFS.ScriptSettings.WriteValue(LastMonitorIdSetting, "" + lastMonitorId);
	}
}