Mod List Sorting System (#971)

* Add mod list sorting system

ModsFolder.getModsList now has an optional parameter to describe the
various sorting
options. Excluding this option produces rather legacy behavior and
should be
backwards-compatible.

Sorted mod lists get cached under a so-called "sort forge," which writes
the key to use
in the cache. If a cache hit occurs, then ModsFolder.getModsList will
use the hit.

Currently, there is support for ascending/descending order and two
modes: clean and
alphabetical sorting. Clean mode provides legacy behavior using this new
system, and
alphabetical sorting uses CoolUtil to sort the list.

ModSwitchMenu has been updated to use this new system, but really, the
only noticeable
change should just be additional memory overhead.

* Integrate mod sorting mode as abstract enum

* Add delimiter for mods in sort forge

* Polish up mod sorting

Most notably, the cache for mod sorting can now be publicly accessed
(although it will be hidden when generating documentation).

This additionally removes a trace that used to be done, and the raw
forge will be used as the key in the cache instead of being hashed
in SHA-256 first (I don't remember why I did that, and to me it seems
fairly useless).

Author: r6915ee

source/funkin/backend/assets/ModsFolder.hx

@@ -2,6 +2,8 @@ package funkin.backend.assets;
 
 import flixel.util.FlxSignal.FlxTypedSignal;
 import funkin.backend.system.MainState;
+import funkin.backend.utils.CoolUtil;
+import haxe.ds.StringMap;
 import haxe.io.Path;
 import lime.text.Font;
 import openfl.text.Font as OpenFLFont;
@@ -42,6 +44,8 @@ class ModsFolder {
 	 * Whenever its the first time mods has been reloaded.
 	 */
 	private static var __firstTime:Bool = true;
+	
+	@:dox(hide) public static var modsListSortCache:StringMap<Array<String>> = new StringMap();
 
 	/**
 	 * Initializes `mods` folder.
@@ -94,7 +98,7 @@ class ModsFolder {
 		#end
 	}
 
-	public static function getModsList():Array<String> {
+	public static function getModsList(?sortingOptions:ModSortingOptions):Array<String> {
 		var mods:Array<String> = [];
 		#if MOD_SUPPORT
 		// Mods directory does not exist yet, create it
@@ -108,6 +112,28 @@ class ModsFolder {
 			if (FileSystem.isDirectory(modsPath + modFolder)) mods.push(modFolder);
 			else if (Flags.ALLOWED_ZIP_EXTENSIONS.contains(Path.extension(modFolder))) mods.push(Path.withoutExtension(modFolder));
 		}
+		
+		if (sortingOptions != null) {
+		    var sortForge:StringBuf = new StringBuf();
+			for (i in mods) {
+			    sortForge.add(i);
+				sortForge.add("::");
+			}
+
+			sortForge.add(Std.string(sortingOptions.descending ? 1 : 0));
+
+			sortForge.add(sortingOptions.mode);
+			
+			final sortForgePure:String = sortForge.toString();
+
+			if (modsListSortCache.exists(sortForgePure))
+			    mods = modsListSortCache.get(sortForgePure);
+				if (mods.length > 0 && mods[mods.length - 1] == null) mods.pop();
+			else {
+			    ModSortingController.sort(sortingOptions, mods);
+				modsListSortCache.set(sortForgePure, mods);
+			}
+		}
 		#end
 		return mods;
 	}
@@ -167,3 +193,48 @@ class ModsFolder {
 	}
 	#end
 }
+
+/**
+ * Describes how mods should be sorted when getting the mods list.
+ */
+typedef ModSortingOptions = {
+    /**
+     * Whether or not the list should go in descending order (e.g. `[2, 1, 0]`).
+     */
+    var descending:Bool;
+    /**
+     * The sorting mode to use.
+     */
+    var mode:ModSortingMode;
+}
+
+/**
+ * This class performs the actual sorting for the mods list.
+ */
+class ModSortingController {
+    /**
+     * Sort the mods list, according to the provided sorting options.
+     */
+    public static function sort(sortingOptions:ModSortingOptions, list:Array<String>):Void {
+        switch (sortingOptions.mode) {
+            case ModSortingMode.CLEAN: {}
+            case ModSortingMode.ALPHABETICAL: CoolUtil.sortAlphabetically(list);
+        }
+        if (sortingOptions.descending) list.reverse();
+    }
+}
+
+/**
+ * The mods list can be sorted in all of the ways provided by this enum.
+ */
+enum abstract ModSortingMode(String) {
+    /**
+     * Use the original list received from reading the directory. This may depend
+     * on the current platform, but remains for legacy purposes.
+     */
+    var CLEAN;
+    /**
+     * The list should be in alphabetical order.
+     */
+    var ALPHABETICAL;
+}

source/funkin/menus/ModSwitchMenu.hx

@@ -29,7 +29,10 @@ class ModSwitchMenu extends MusicBeatSubstate {
 		bg.alpha = 0;
 		FlxTween.tween(bg, {alpha: 0.5}, 0.25, {ease: FlxEase.cubeOut});
 
-		mods = ModsFolder.getModsList();
+		mods = ModsFolder.getModsList({
+		    descending: false,
+			mode: CLEAN,
+		});
 		mods.push(null);
 
 		alphabets = new FlxTypedGroup<Alphabet>();