package net.minecraft.client.renderer.block.dispatch;

import com.google.common.base.Splitter;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import java.util.Objects;
import java.util.Map.Entry;
import java.util.function.Predicate;
import net.minecraft.world.level.block.state.StateDefinition;
import net.minecraft.world.level.block.state.StateHolder;
import net.minecraft.world.level.block.state.properties.Property;
import org.jspecify.annotations.Nullable;

public class VariantSelector {
	private static final Splitter COMMA_SPLITTER = Splitter.on(',');
	private static final Splitter EQUAL_SPLITTER = Splitter.on('=').limit(2);

	public static <O, S extends StateHolder<O, S>> Predicate<StateHolder<O, S>> predicate(final StateDefinition<O, S> stateDefinition, final String properties) {
		Map<Property<?>, Comparable<?>> map = new HashMap();

		for (String keyValue : COMMA_SPLITTER.split(properties)) {
			Iterator<String> iterator = EQUAL_SPLITTER.split(keyValue).iterator();
			if (iterator.hasNext()) {
				String propertyName = (String)iterator.next();
				Property<?> property = stateDefinition.getProperty(propertyName);
				if (property != null && iterator.hasNext()) {
					String propertyValue = (String)iterator.next();
					Comparable<?> value = getValueHelper((Property<Comparable<?>>)property, propertyValue);
					if (value == null) {
						throw new RuntimeException("Unknown value: '" + propertyValue + "' for blockstate property: '" + propertyName + "' " + property.getPossibleValues());
					}

					map.put(property, value);
				} else if (!propertyName.isEmpty()) {
					throw new RuntimeException("Unknown blockstate property: '" + propertyName + "'");
				}
			}
		}

		return input -> {
			for (Entry<Property<?>, Comparable<?>> entry : map.entrySet()) {
				if (!Objects.equals(input.getValue((Property)entry.getKey()), entry.getValue())) {
					return false;
				}
			}

			return true;
		};
	}

	@Nullable
	private static <T extends Comparable<T>> T getValueHelper(final Property<T> property, final String next) {
		return (T)property.getValue(next).orElse(null);
	}
}