package net.minecraft.client.data.models.blockstates;

import java.util.ArrayList;
import java.util.List;
import java.util.Optional;
import net.fabricmc.api.EnvType;
import net.fabricmc.api.Environment;
import net.minecraft.client.data.models.MultiVariant;
import net.minecraft.client.renderer.block.model.BlockModelDefinition;
import net.minecraft.client.renderer.block.model.multipart.Condition;
import net.minecraft.client.renderer.block.model.multipart.Selector;
import net.minecraft.world.level.block.Block;

@Environment(EnvType.CLIENT)
public class MultiPartGenerator implements BlockModelDefinitionGenerator {
	private final Block block;
	private final List<MultiPartGenerator.Entry> parts = new ArrayList();

	private MultiPartGenerator(Block block) {
		this.block = block;
	}

	@Override
	public Block block() {
		return this.block;
	}

	public static MultiPartGenerator multiPart(Block block) {
		return new MultiPartGenerator(block);
	}

	public MultiPartGenerator with(MultiVariant variants) {
		this.parts.add(new MultiPartGenerator.Entry(Optional.empty(), variants));
		return this;
	}

	private void validateCondition(Condition condition) {
		condition.instantiate(this.block.getStateDefinition());
	}

	public MultiPartGenerator with(Condition condition, MultiVariant variants) {
		this.validateCondition(condition);
		this.parts.add(new MultiPartGenerator.Entry(Optional.of(condition), variants));
		return this;
	}

	public MultiPartGenerator with(ConditionBuilder condition, MultiVariant variants) {
		return this.with(condition.build(), variants);
	}

	@Override
	public BlockModelDefinition create() {
		return new BlockModelDefinition(
			Optional.empty(), Optional.of(new BlockModelDefinition.MultiPartDefinition(this.parts.stream().map(MultiPartGenerator.Entry::toUnbaked).toList()))
		);
	}

	@Environment(EnvType.CLIENT)
	record Entry(Optional<Condition> condition, MultiVariant variants) {
		public Selector toUnbaked() {
			return new Selector(this.condition, this.variants.toUnbaked());
		}
	}
}