package io.gitlab.jfronny.inceptum.util;

import java.lang.reflect.Field;
import java.lang.reflect.InvocationTargetException;
import java.util.*;

public class DeepCloner {
    public static <T> T clone(T source) {
        try {
            return (T) cloneI(source);
        } catch (NoSuchMethodException | IllegalAccessException | InvocationTargetException | InstantiationException e) {
            throw new RuntimeException("Could not clone object", e);
        }
    }

    private static Object cloneI(Object source) throws NoSuchMethodException, IllegalAccessException, InvocationTargetException, InstantiationException {
        if (source == null) return null;
        if (source instanceof String
                || source instanceof Integer
                || source instanceof Byte
                || source instanceof Short
                || source instanceof Double
                || source instanceof Float)
            return source;
        if (source instanceof List<?> list) return List.copyOf(list);
        if (source instanceof Map<?, ?> map) return Map.copyOf(map);
        if (source instanceof Set<?> set) return new LinkedHashSet<>(set);
        if (source instanceof Date date) return new Date(date.getTime());
        Class<?> klazz = source.getClass();
        if (!klazz.getName().startsWith("io.gitlab.jfronny.inceptum.model"))
            throw new IllegalStateException("Default java classes must have special impls! (" + klazz.getName() + ")");
        Object instance = klazz.getConstructor().newInstance();
        for (Field field : klazz.getFields())
            field.set(instance, cloneI(field.get(source)));
        return instance;
    }
}