The shit needed for undo/redo implementation in FNF's charting state

FNFChartingUndoRedo.hx

enum abstract ChartActionType(Int) from Int to Int {
	var AddNote:Int = 0;
	var RemoveNote:Int = 1;	
	var AddEvent:Int = 2;
	var RemoveEvent:Int = 3;
}
typedef ChartAction = {
	var action:ChartActionType;
	var data:Dynamic;
}

var chartActions:Array<ChartAction> = [];
var undoneStuff:Array<ChartAction> = [];

function undo() {
		if (chartActions.length == 0) return;
		trace(chartActions);
		var cA = chartActions[chartActions.length - 1];
		switch (cA.action) {
			case AddNote:
				_song.notes[curSec].sectionNotes.remove(cA.data);
				if (curSelectedNote == cA.data)
					curSelectedNote = null;
			case RemoveNote:
				_song.notes[curSec].sectionNotes.push(cA.data);
				curSelectedNote = cA.data;
			case AddEvent:
				_song.events.remove(cA.data);
				if (curSelectedNote == cA.data)
					curSelectedNote = null;
			case RemoveEvent:
				_song.events.push(cA.data);
				curSelectedNote = cA.data;
		}

		undoneStuff.push(cA);
		chartActions.pop();
		updateGrid();
	}

	function redo() {
		if (undoneStuff.length == 0) return;
		trace(undoneStuff);
		var cA = undoneStuff[undoneStuff.length - 1];

		switch (cA.action) {
			case AddNote:
				_song.notes[curSec].sectionNotes.push(cA.data);
				curSelectedNote = cA.data;
			case RemoveNote:
				_song.notes[curSec].sectionNotes.remove(cA.data);
				if (curSelectedNote == cA.data)
					curSelectedNote = null;
			case AddEvent:
				_song.events.push(cA.data);
				curSelectedNote = cA.data;
			case RemoveEvent:
				_song.events.remove(cA.data);
				if (curSelectedNote == cA.data)
					curSelectedNote = null;
		}

		undoneStuff.pop();
		chartActions.push(cA);
		updateGrid();
	}