package net.minecraft.world.entity.boss.enderdragon.phases;

import com.mojang.logging.LogUtils;
import java.util.Objects;
import net.minecraft.world.entity.boss.enderdragon.EnderDragon;
import org.jspecify.annotations.Nullable;
import org.slf4j.Logger;

public class EnderDragonPhaseManager {
	private static final Logger LOGGER = LogUtils.getLogger();
	private final EnderDragon dragon;
	private final DragonPhaseInstance[] phases = new DragonPhaseInstance[EnderDragonPhase.getCount()];
	@Nullable
	private DragonPhaseInstance currentPhase;

	public EnderDragonPhaseManager(final EnderDragon dragon) {
		this.dragon = dragon;
		this.setPhase(EnderDragonPhase.HOVERING);
	}

	public void setPhase(final EnderDragonPhase<?> target) {
		if (this.currentPhase == null || target != this.currentPhase.getPhase()) {
			if (this.currentPhase != null) {
				this.currentPhase.end();
			}

			this.currentPhase = this.getPhase((EnderDragonPhase<DragonPhaseInstance>)target);
			if (!this.dragon.level().isClientSide()) {
				this.dragon.getEntityData().set(EnderDragon.DATA_PHASE, target.getId());
			}

			LOGGER.debug("Dragon is now in phase {} on the {}", target, this.dragon.level().isClientSide() ? "client" : "server");
			this.currentPhase.begin();
		}
	}

	public DragonPhaseInstance getCurrentPhase() {
		return (DragonPhaseInstance)Objects.requireNonNull(this.currentPhase);
	}

	public <T extends DragonPhaseInstance> T getPhase(final EnderDragonPhase<T> phase) {
		int id = phase.getId();
		DragonPhaseInstance phaseInstance = this.phases[id];
		if (phaseInstance == null) {
			phaseInstance = phase.createInstance(this.dragon);
			this.phases[id] = phaseInstance;
		}

		return (T)phaseInstance;
	}
}