// Fill out your copyright notice in the Description page of Project Settings.

#pragma once

#include "CoreMinimal.h"

/**
 * Re-reads the place every NPC schedule sends its NPCs to.
 *
 * A schedule names its anchor by PersistentId and keeps a copy of where that anchor stood when it was
 * picked beside it, see FScheduledAction::AnchorTransform. That copy is what an NPC is sent at while
 * its anchor sits in a cell nobody has loaded, and it is written once, when the anchor is picked in
 * the details panel. The furniture it is a copy of can be moved afterwards without anybody picking
 * anything again, and then the two disagree: the schedule says the bed is where it used to be, and
 * the level says otherwise.
 *
 * This is the sweep that closes that gap. It stands every anchor the open level can answer for
 * against the copy its schedule holds, writes the ones that have moved, and saves the assets that
 * changed. It is an editor tool rather than something the game runs, because the drift is a fault in
 * the authored data and not in what a running game does with it: nothing reads the copy while it can
 * see the anchor itself, so a game never notices, and the schedule only starts lying when an NPC
 * meets a level that has the anchor streamed out.
 *
 * The one thing it cannot answer is an anchor that is not in the open level, which is either
 * furniture in a cell that is not loaded or a schedule naming something that is gone. Nothing here
 * can tell those two apart, so both are counted and reported rather than guessed at, and the copies
 * they belong to are left exactly as they were.
 */
namespace ScheduleAssetRecheck
{
	/** What one sweep found, so that a caller can say it out loud rather than only log it. */
	struct FResult
	{
		/** Assets the registry handed over, whether or not anything in them had moved. */
		int32 NumAssetsScanned = 0;

		/** Assets that no longer agreed with the level, and so were written and saved. */
		int32 NumAssetsUpdated = 0;

		/** Actions carrying an anchor, which is every action there is a place to check for. An action
		 *  with no anchor happens wherever the NPC already is and has nothing to go stale. */
		int32 NumAnchorsChecked = 0;

		/** Copies that had moved, or that had never been recorded at all. */
		int32 NumAnchorsUpdated = 0;

		/** Anchors no actor in the open level claims, whose copies were left as they were. */
		int32 NumAnchorsUnresolved = 0;
	};

	/** Walks every NpcScheduleAsset in the project, refreshes the anchor copy of every action whose
	 *  anchor is standing in the open level, and saves the assets that changed.
	 *
	 *  The editor world is the only one read, so what this answers for is exactly what the level in
	 *  front of the author can see, and a schedule whose anchors live in some other level is left
	 *  alone by the same rule that leaves an unloaded cell alone. What it did is reported through a
	 *  notification and the log, and returned here as well, for a caller that wants the numbers. */
	FResult RecheckAllScheduleAssets();
}