package net.minecraft.world.entity;

import java.util.ArrayList;
import java.util.EnumSet;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.function.Consumer;
import net.minecraft.util.Util;

public interface InsideBlockEffectApplier {
	InsideBlockEffectApplier NOOP = new InsideBlockEffectApplier() {
		@Override
		public void apply(final InsideBlockEffectType type) {
		}

		@Override
		public void runBefore(final InsideBlockEffectType type, final Consumer<Entity> effect) {
		}

		@Override
		public void runAfter(final InsideBlockEffectType type, final Consumer<Entity> effect) {
		}
	};

	void apply(InsideBlockEffectType type);

	void runBefore(InsideBlockEffectType type, Consumer<Entity> effect);

	void runAfter(InsideBlockEffectType type, Consumer<Entity> effect);

	public static class StepBasedCollector implements InsideBlockEffectApplier {
		private static final InsideBlockEffectType[] APPLY_ORDER = InsideBlockEffectType.values();
		private static final int NO_STEP = -1;
		private final Set<InsideBlockEffectType> effectsInStep = EnumSet.noneOf(InsideBlockEffectType.class);
		private final Map<InsideBlockEffectType, List<Consumer<Entity>>> beforeEffectsInStep = Util.makeEnumMap(InsideBlockEffectType.class, type -> new ArrayList());
		private final Map<InsideBlockEffectType, List<Consumer<Entity>>> afterEffectsInStep = Util.makeEnumMap(InsideBlockEffectType.class, type -> new ArrayList());
		private final List<Consumer<Entity>> finalEffects = new ArrayList();
		private int lastStep = -1;

		public void advanceStep(final int step) {
			if (this.lastStep != step) {
				this.lastStep = step;
				this.flushStep();
			}
		}

		public void applyAndClear(final Entity entity) {
			this.flushStep();

			for (Consumer<Entity> effect : this.finalEffects) {
				if (!entity.isAlive()) {
					break;
				}

				effect.accept(entity);
			}

			this.finalEffects.clear();
			this.lastStep = -1;
		}

		private void flushStep() {
			for (InsideBlockEffectType type : APPLY_ORDER) {
				List<Consumer<Entity>> beforeEffects = (List<Consumer<Entity>>)this.beforeEffectsInStep.get(type);
				this.finalEffects.addAll(beforeEffects);
				beforeEffects.clear();
				if (this.effectsInStep.remove(type)) {
					this.finalEffects.add(type.effect());
				}

				List<Consumer<Entity>> afterEffects = (List<Consumer<Entity>>)this.afterEffectsInStep.get(type);
				this.finalEffects.addAll(afterEffects);
				afterEffects.clear();
			}
		}

		@Override
		public void apply(final InsideBlockEffectType type) {
			this.effectsInStep.add(type);
		}

		@Override
		public void runBefore(final InsideBlockEffectType type, final Consumer<Entity> effect) {
			((List)this.beforeEffectsInStep.get(type)).add(effect);
		}

		@Override
		public void runAfter(final InsideBlockEffectType type, final Consumer<Entity> effect) {
			((List)this.afterEffectsInStep.get(type)).add(effect);
		}
	}
}