package game.command;

import java.util.function.Function;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

public class PatternReplacer {
	private final String variable;
	private final boolean matchAll;
	private final Pattern pattern;
	private final Function<String, String> function;
	
	public PatternReplacer(String variable, boolean matchAll, Function<String, String> function) {
		this.variable = variable;
		this.matchAll = matchAll;
		this.pattern = Pattern.compile("\\$\\((" + Pattern.quote(variable) + (matchAll ? "[^\\)]*" : "") + ")\\)");
		this.function = function;
	}
	
	public void replaceVar(StringBuffer sb) {
		String str = sb.toString();
		sb.delete(0, sb.length());
		Matcher matcher = this.pattern.matcher(str);
		while(matcher.find()) {
			String orig = matcher.group(1);
			String rep = this.function.apply(orig);
			if(rep == null)
				throw new RunException("Variable '%s' konnte in diesem Kontext nicht ersetzt werden", orig);
			matcher.appendReplacement(sb, rep);
		}
		matcher.appendTail(sb);
	}
	
	public String getVariable() {
		return this.variable;
	}
	
	public boolean matchesAll() {
		return this.matchAll;
	}
	
	public Pattern getPattern() {
		return this.pattern;
	}
	
	public Function<String, String> getFunction() {
		return this.function;
	}
}