code:

function OnCreation(XComGameState NewGameState, bool bGoldenPathSpawn)
{
	SetInterceptionChance(NewGameState, bGoldenPathSpawn);
	SetLocationHuntXCom();
	SetVisible();
	
	`XEVENTMGR.TriggerEvent('UFOSpawned', , , NewGameState);
}

//---------------------------------------------------------------------------------------
// Set whether or not this UFO will succeed in its interception attempt
function SetInterceptionChance(XComGameState NewGameState, bool bGoldenPathSpawn)
{
	local XComGameStateHistory History;
	local XComGameState_HeadquartersAlien AlienHQ;
	local int IntChance;
	
	History = `XCOMHISTORY;
	AlienHQ = XComGameState_HeadquartersAlien(History.GetSingleGameStateObjectForClass(class'XComGameState_HeadquartersAlien'));
	bGoldenPath = bGoldenPathSpawn;

	if (!AlienHQ.bHasPlayerBeenIntercepted)
	{
		IntChance = bGoldenPathSpawn ? DefaultInterceptionChanceGoldenPath : DefaultInterceptionChance;
	}
	else
	{
		IntChance = AfterFirstInterceptionChance[`DIFFICULTYSETTING];
	}

	bDoesInterceptionSucceed = class'X2StrategyGameRulesetDataStructures'.static.Roll(IntChance);

	// If the UFO intercepts the player, flag Alien HQ so any subsequent UFO spawns will use the correct percentages
	if (bDoesInterceptionSucceed)
	{
		AlienHQ = XComGameState_HeadquartersAlien(NewGameState.CreateStateObject(class'XComGameState_HeadquartersAlien', AlienHQ.ObjectID));
		NewGameState.AddStateObject(AlienHQ);
		AlienHQ.bHasPlayerBeenIntercepted = true;
	}
	else if (!AlienHQ.bHasPlayerAvoidedUFO) // If the player avoids interception, let AlienHQ know. Used for spawning Landed UFO supply raids.
	{
		AlienHQ = XComGameState_HeadquartersAlien(NewGameState.CreateStateObject(class'XComGameState_HeadquartersAlien', AlienHQ.ObjectID));
		NewGameState.AddStateObject(AlienHQ);
		AlienHQ.bHasPlayerAvoidedUFO = true;
	}
	
	SetInterceptionTime();
}


//---------------------------------------------------------------------------------------
// Sets the time when this UFO will attempt to intercept the Avenger
function SetInterceptionTime()
{
	local XComGameState_MissionCalendar CalendarState;
	local int HoursUntilIntercept;

	SpawnTime = GetCurrentTime();

	if (bDoesInterceptionSucceed)
	{
		CalendarState = XComGameState_MissionCalendar(`XCOMHISTORY.GetSingleGameStateObjectForClass(class'XComGameState_MissionCalendar'));
		InterceptionTime = CalendarState.GetBestNewMissionDateBetweenMissions(MaxInterceptMissionsToWait);
	}
	else
	{
		HoursUntilIntercept = (MinNonInterceptDays * 24) + `SYNC_RAND((MaxNonInterceptDays * 24) - (MinNonInterceptDays * 24) + 1);
		InterceptionTime = GetCurrentTime();
		class'X2StrategyGameRulesetDataStructures'.static.AddHours(InterceptionTime, HoursUntilIntercept);
	}
}

// some update function, but here's the important stuff
			// If we have hit our interception time, become visible, transport to be close to XComHQ, and start the attack
			if (class'X2StrategyGameRulesetDataStructures'.static.LessThan(InterceptionTime, GetCurrentTime()))
			{