"Add Output Index" script for old Automapping rules (#26)

This script scans a project or a directory for Automapping rules and 
updates them to ensure they will work consistently with 1.10.3+ 
Automapping, which changes how empty indices are handled.

In any map that has both empty and non-empty output indices, it gives 
the empty index a name, so that it stays just a regular random index
like it was before 1.10.3, instead of becoming a special "always output"
layer.

AddOutputIndex.js

@@ -0,0 +1,152 @@
+/* 	Add Output Index script by eishiya, last updated 15 Mar 2024
+
+	Requires Tiled 1.10.2+
+
+	As of Tiled 1.10.3, output layers without an index always get output.
+	Before, such layers would simply count as another index to choose at random.
+	This causes a potential change in behaviour for older Automapping rules.
+	
+	This script adds an action to the Map menu that updates old rules
+	to work the same as they did before.
+	For any rules map it finds that has output layers with named indices,
+	any output layers *without* named indices get a named index.
+	
+	This script will attempt to fix commented-out layer names too,
+	as long as they're otherwise valid, e.g.
+	"//output_Blah" will get fixed, "//TODO: output_Blah" will not.
+	
+	The replacement index will be "0". If such an index already exists
+	in the map, it will be "00", and so on.
+		
+	Any maps that are modified by the script will be left open and not saved.
+	This makes it easier for you to verify the changes. You can Save All if you
+	don't want to check and save each one manually.
+
+	If you have a Project loaded, the project's directories will be scanned.
+	Otherwise, you'll be prompted to select a directory to scan.
+	
+	If you have many maps, this script can take a while to run!
+	
+	You should only need to run this script once per pre-1.10.3 Project.
+	You can uninstall it when you're done, or comment out the last 3 lines so
+	it doesn't clutter your Map menu, in which case you can still run the script
+	via Search Actions.
+*/
+
+let addOutputIndex = tiled.registerAction("AddOutputIndex", function(/* action */) {
+	function fixIndex(map) {
+		let newIndexCharacter = "0";
+		let newIndex = newIndexCharacter;
+
+		let layersToRename = [];
+		let hasNamedIndices = false;
+		function checkLayer(layer) {
+			if(!layer) return;
+			if(layer.isGroupLayer || layer.isTileMap) {
+				//process over its child layers recursively:
+				for(let gi = 0; gi < layer.layerCount; ++gi) {
+					checkLayer(layer.layerAt(gi));
+				}
+			} else { //regular layer that may be an output layer
+				let layerName = layer.name;
+				//to fix commented-out layers, strip the comment bit:
+				layerName.replace(/^(\/\/|#)\s*/, '');
+				if(layerName.indexOf("output_") == 0) //output with unnamed index
+					layersToRename.push(layer);
+				else {
+					//the name has output but not output_, it must have a named output index
+					if(layerName.indexOf("output") == 0)
+						hasNamedIndices = true;
+					//If our new index would conflict with an existing index, change it:
+					while(layerName.indexOf("output"+newIndex+"_") == 0)
+						newIndex += newIndexCharacter;
+				}
+			}
+		}
+		checkLayer(map);
+
+		if(hasNamedIndices && layersToRename.length > 0) {
+			map.macro("Add Output Index", function() {
+				for(let layer of layersToRename)
+					layer.name = layer.name.replace("output_", "output"+newIndex+"_");
+				tiled.log("Renamed "+layersToRename.length+" layer(s) in "+map.fileName);
+			});
+
+			return layersToRename.length;
+		}
+		return 0;
+	}
+
+	let maps = [];
+
+	//Helper function that returns a TileMap if it's already open
+	function getOpenMap(file) {
+		for(let asset of tiled.openAssets) {
+			if(asset.fileName == file && asset.isTileMap)
+				return asset;
+		}
+		return null;
+	}
+
+	//Recursively add all the maps in a folder to maps
+	let checkedFolders = {};
+	function collectMaps(folder) {
+		let canonicalPath = FileInfo.canonicalPath(folder);
+		if(checkedFolders[canonicalPath]) return;
+
+		checkedFolders[canonicalPath] = true;
+		//First, get all the files in this folder
+		let files = File.directoryEntries(folder, File.Files | File.Readable | File.NoDotAndDotDot);
+		for(let file of files) {
+			let path = folder+"/"+file;
+			let format = tiled.mapFormatForFile(path);
+			if(format) {
+				let map = getOpenMap(path);
+				if(map)
+					maps.push(map);
+				else
+					maps.push(path);
+			} //else there's no map format that can read this file, it's not a Tiled map, skip it.
+		}
+		//Then, look at any subfolders:
+		files = File.directoryEntries(folder, File.Dirs | File.Readable | File.NoDotAndDotDot);
+		for(let file of files) {
+			collectMaps(folder+"/"+file);
+		}
+	}
+
+	let folders;
+	if(tiled.project && tiled.projectFilePath.length > 0)
+		folders = tiled.project.folders;
+	else
+		folders = [tiled.promptDirectory(null, "Select a directory to scan")];
+
+	for(let folder of folders)
+		collectMaps(folder);
+
+	let previousAsset = tiled.activeAsset;
+	let totalLayersChanged = 0;
+
+	for(let map of maps) {
+		if(map.isTileMap) {
+			totalLayersChanged += fixIndex(map);
+		} else { //a path
+			map = tiled.open(map);
+			let layersChanged = fixIndex(map);
+			totalLayersChanged += layersChanged;
+			if(layersChanged == 0) //leave modified maps open for inspection
+				tiled.close(map);
+		}
+	}
+
+	if(totalLayersChanged == 0)
+		tiled.log("No maps were found to need output index modification. No changes made.");
+	if(previousAsset)
+		tiled.activeAsset = previousAsset;
+});
+addOutputIndex.text = "Add Output Indices";
+
+//Add this action to the Map menu:
+tiled.extendMenu("Map", [
+	{ action: "AddOutputIndex", before: "AutoMapWhileDrawing" }
+]);