A replace util function for Sponge's Text

TextUtils.java

package de.bluecolored.spongeutil;

import java.util.ArrayList;
import java.util.List;
import java.util.Optional;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

import org.spongepowered.api.text.LiteralText;
import org.spongepowered.api.text.Text;
import org.spongepowered.api.text.TextRepresentable;
import org.spongepowered.api.text.action.HoverAction;
import org.spongepowered.api.text.action.HoverAction.ShowText;
import org.spongepowered.api.text.action.TextActions;

public class TextUtils {

	public static Text replace(Text haystack, String needle, Object replacement){
		
		//prepare builder
		Text.Builder b = haystack.toBuilder();
		
		//prepare children
		List<Text> childs = new ArrayList<>();
		childs.addAll(b.getChildren());
		b.removeAll();
		
		//replace hover
		Optional<HoverAction<?>> ha = b.getHoverAction();
		if (ha.isPresent() && ha.get() instanceof ShowText){
			ShowText st = (ShowText) ha.get();
			Text newHover = replace(st.getResult(), needle, replacement);
			b.onHover(TextActions.showText(newHover));
		}
		
		//prepare replacement
		Text replacementText = null;
		if (replacement instanceof TextRepresentable){
			replacementText = ((TextRepresentable) replacement).toText();
		}
		
		//modify plain
		if (b instanceof LiteralText.Builder){
			LiteralText.Builder lb = (LiteralText.Builder) b;
			if (replacementText == null){
				String newContent = lb.getContent().replace(needle, replacement.toString());
				lb.content(newContent);
			} else {
				String cont = lb.getContent();
				lb.content("");
				
				List<Text> parts = new ArrayList<>(3);
				
				Matcher m = Pattern.compile(Pattern.quote(needle)).matcher(cont);
				int pointer = 0;
				while(m.find()){
					if (m.start() > pointer){
						parts.add(Text.of(cont.substring(pointer, m.start())));
					}
					
					parts.add(replacementText);
					pointer = m.end();
				}
				
				if (cont.length() > pointer){
					parts.add(Text.of(cont.substring(pointer, cont.length())));
				}
				
				lb.append(parts);
			}
		}
		
		//add children back
		for (Text c : childs){
			b.append(replace(c, needle, replacement));
		}
		
		return b.build();
	}
}