package org.simantics.scl.runtime.procedure;

import java.util.Random;

import org.simantics.scl.runtime.SCLContext;
import org.simantics.scl.runtime.function.Function;
import org.simantics.scl.runtime.tuple.Tuple0;

public class RandomEffect {
    public static final String RANDOM = "random";
    
    public static Object withSeed(long seed, Function fun) {
        SCLContext context = SCLContext.getCurrent();
        Random oldRandom = (Random)context.put(RANDOM, new Random(seed));
        try {
            return fun.apply(Tuple0.INSTANCE);
        } finally {
            context.put(RANDOM, oldRandom);
        }
    }
    
    public static Object runRandom(Function fun) {
        SCLContext context = SCLContext.getCurrent();
        Random oldRandom = (Random)context.put(RANDOM, new Random());
        try {
            return fun.apply(Tuple0.INSTANCE);
        } finally {
            context.put(RANDOM, oldRandom);
        }
    }
}