package net.minecraft.world.damagesource;

import com.google.common.collect.Lists;
import java.util.List;
import java.util.Objects;
import net.minecraft.core.component.DataComponents;
import net.minecraft.network.chat.ClickEvent;
import net.minecraft.network.chat.Component;
import net.minecraft.network.chat.ComponentUtils;
import net.minecraft.network.chat.HoverEvent;
import net.minecraft.network.chat.Style;
import net.minecraft.tags.DamageTypeTags;
import net.minecraft.util.CommonLinks;
import net.minecraft.world.entity.Entity;
import net.minecraft.world.entity.LivingEntity;
import net.minecraft.world.item.ItemStack;
import org.jspecify.annotations.Nullable;

public class CombatTracker {
	public static final int RESET_DAMAGE_STATUS_TIME = 100;
	public static final int RESET_COMBAT_STATUS_TIME = 300;
	private static final Style INTENTIONAL_GAME_DESIGN_STYLE = Style.EMPTY
		.withClickEvent(new ClickEvent.OpenUrl(CommonLinks.INTENTIONAL_GAME_DESIGN_BUG))
		.withHoverEvent(new HoverEvent.ShowText(Component.literal("MCPE-28723")));
	private final List<CombatEntry> entries = Lists.<CombatEntry>newArrayList();
	private final LivingEntity mob;
	private int lastDamageTime;
	private int combatStartTime;
	private int combatEndTime;
	private boolean inCombat;
	private boolean takingDamage;

	public CombatTracker(final LivingEntity mob) {
		this.mob = mob;
	}

	public void recordDamage(final DamageSource source, final float damage) {
		this.recheckStatus();
		FallLocation fallLocation = FallLocation.getCurrentFallLocation(this.mob);
		CombatEntry entry = new CombatEntry(source, damage, fallLocation, (float)this.mob.fallDistance);
		this.entries.add(entry);
		this.lastDamageTime = this.mob.tickCount;
		this.takingDamage = true;
		if (!this.inCombat && this.mob.isAlive() && shouldEnterCombat(source)) {
			this.inCombat = true;
			this.combatStartTime = this.mob.tickCount;
			this.combatEndTime = this.combatStartTime;
			this.mob.onEnterCombat();
		}
	}

	private static boolean shouldEnterCombat(final DamageSource source) {
		return source.getEntity() instanceof LivingEntity;
	}

	private Component getMessageForAssistedFall(
		final Entity attackerEntity, final Component attackerName, final String messageWithItem, final String messageWithoutItem
	) {
		ItemStack attackerItem = attackerEntity instanceof LivingEntity livingEntity ? livingEntity.getMainHandItem() : ItemStack.EMPTY;
		return !attackerItem.isEmpty() && attackerItem.has(DataComponents.CUSTOM_NAME)
			? Component.translatable(messageWithItem, this.mob.getDisplayName(), attackerName, attackerItem.getDisplayName())
			: Component.translatable(messageWithoutItem, this.mob.getDisplayName(), attackerName);
	}

	private Component getFallMessage(final CombatEntry knockOffEntry, @Nullable final Entity killingEntity) {
		DamageSource knockOffSource = knockOffEntry.source();
		if (!knockOffSource.is(DamageTypeTags.IS_FALL) && !knockOffSource.is(DamageTypeTags.ALWAYS_MOST_SIGNIFICANT_FALL)) {
			Component killerName = getDisplayName(killingEntity);
			Entity attackerEntity = knockOffSource.getEntity();
			Component attackerName = getDisplayName(attackerEntity);
			if (attackerName != null && !attackerName.equals(killerName)) {
				return this.getMessageForAssistedFall(attackerEntity, attackerName, "death.fell.assist.item", "death.fell.assist");
			} else {
				return (Component)(killerName != null
					? this.getMessageForAssistedFall(killingEntity, killerName, "death.fell.finish.item", "death.fell.finish")
					: Component.translatable("death.fell.killer", this.mob.getDisplayName()));
			}
		} else {
			FallLocation fallLocation = (FallLocation)Objects.requireNonNullElse(knockOffEntry.fallLocation(), FallLocation.GENERIC);
			return Component.translatable(fallLocation.languageKey(), this.mob.getDisplayName());
		}
	}

	@Nullable
	private static Component getDisplayName(@Nullable final Entity entity) {
		return entity == null ? null : entity.getDisplayName();
	}

	public Component getDeathMessage() {
		if (this.entries.isEmpty()) {
			return Component.translatable("death.attack.generic", this.mob.getDisplayName());
		} else {
			CombatEntry killingBlow = (CombatEntry)this.entries.get(this.entries.size() - 1);
			DamageSource killingSource = killingBlow.source();
			CombatEntry knockOffEntry = this.getMostSignificantFall();
			DeathMessageType messageType = killingSource.type().deathMessageType();
			if (messageType == DeathMessageType.FALL_VARIANTS && knockOffEntry != null) {
				return this.getFallMessage(knockOffEntry, killingSource.getEntity());
			} else if (messageType == DeathMessageType.INTENTIONAL_GAME_DESIGN) {
				String deathMsg = "death.attack." + killingSource.getMsgId();
				Component link = ComponentUtils.wrapInSquareBrackets(Component.translatable(deathMsg + ".link")).withStyle(INTENTIONAL_GAME_DESIGN_STYLE);
				return Component.translatable(deathMsg + ".message", this.mob.getDisplayName(), link);
			} else {
				return killingSource.getLocalizedDeathMessage(this.mob);
			}
		}
	}

	@Nullable
	private CombatEntry getMostSignificantFall() {
		CombatEntry result = null;
		CombatEntry alternative = null;
		float altDamage = 0.0F;
		float bestFall = 0.0F;

		for (int i = 0; i < this.entries.size(); i++) {
			CombatEntry entry = (CombatEntry)this.entries.get(i);
			CombatEntry previous = i > 0 ? (CombatEntry)this.entries.get(i - 1) : null;
			DamageSource source = entry.source();
			boolean isFakeFall = source.is(DamageTypeTags.ALWAYS_MOST_SIGNIFICANT_FALL);
			float fallDistance = isFakeFall ? Float.MAX_VALUE : entry.fallDistance();
			if ((source.is(DamageTypeTags.IS_FALL) || isFakeFall) && fallDistance > 0.0F && (result == null || fallDistance > bestFall)) {
				if (i > 0) {
					result = previous;
				} else {
					result = entry;
				}

				bestFall = fallDistance;
			}

			if (entry.fallLocation() != null && (alternative == null || entry.damage() > altDamage)) {
				alternative = entry;
				altDamage = entry.damage();
			}
		}

		if (bestFall > 5.0F && result != null) {
			return result;
		} else {
			return altDamage > 5.0F && alternative != null ? alternative : null;
		}
	}

	public int getCombatDuration() {
		return this.inCombat ? this.mob.tickCount - this.combatStartTime : this.combatEndTime - this.combatStartTime;
	}

	public void recheckStatus() {
		int reset = this.inCombat ? 300 : 100;
		if (this.takingDamage && (!this.mob.isAlive() || this.mob.tickCount - this.lastDamageTime > reset)) {
			boolean wasInCombat = this.inCombat;
			this.takingDamage = false;
			this.inCombat = false;
			this.combatEndTime = this.mob.tickCount;
			if (wasInCombat) {
				this.mob.onLeaveCombat();
			}

			this.entries.clear();
		}
	}
}