package com.minelittlepony.unicopia.entity;

import java.util.*;
import java.util.stream.Stream;
import java.util.stream.StreamSupport;

import org.jetbrains.annotations.Nullable;

import com.google.common.base.Preconditions;
import com.minelittlepony.unicopia.USounds;
import com.minelittlepony.unicopia.UTags;
import com.minelittlepony.unicopia.Unicopia;
import com.minelittlepony.unicopia.ability.Abilities;
import com.minelittlepony.unicopia.ability.magic.Caster;
import com.minelittlepony.unicopia.ability.magic.SpellContainer;
import com.minelittlepony.unicopia.ability.magic.SpellPredicate;
import com.minelittlepony.unicopia.ability.magic.SpellContainer.Operation;
import com.minelittlepony.unicopia.ability.magic.spell.AbstractDisguiseSpell;
import com.minelittlepony.unicopia.ability.magic.spell.Situation;
import com.minelittlepony.unicopia.advancement.UCriteria;
import com.minelittlepony.unicopia.entity.behaviour.EntityAppearance;
import com.minelittlepony.unicopia.entity.duck.LivingEntityDuck;
import com.minelittlepony.unicopia.entity.effect.UEffects;
import com.minelittlepony.unicopia.entity.player.Pony;
import com.minelittlepony.unicopia.input.Heuristic;
import com.minelittlepony.unicopia.input.Interactable;
import com.minelittlepony.unicopia.item.GlassesItem;
import com.minelittlepony.unicopia.item.UItems;
import com.minelittlepony.unicopia.network.datasync.EffectSync;
import com.minelittlepony.unicopia.network.datasync.Transmittable;
import com.minelittlepony.unicopia.particle.ParticleUtils;
import com.minelittlepony.unicopia.projectile.ProjectileImpactListener;
import com.minelittlepony.unicopia.server.world.DragonBreathStore;
import com.minelittlepony.unicopia.trinkets.TrinketsDelegate;
import com.minelittlepony.unicopia.util.*;

import it.unimi.dsi.fastutil.floats.Float2ObjectFunction;
import net.minecraft.entity.*;
import net.minecraft.entity.attribute.EntityAttribute;
import net.minecraft.entity.attribute.EntityAttributeInstance;
import net.minecraft.entity.attribute.EntityAttributeModifier;
import net.minecraft.entity.damage.DamageSource;
import net.minecraft.entity.data.*;
import net.minecraft.entity.player.PlayerEntity;
import net.minecraft.entity.projectile.ProjectileEntity;
import net.minecraft.item.ItemStack;
import net.minecraft.nbt.NbtCompound;
import net.minecraft.network.packet.s2c.play.EntityPassengersSetS2CPacket;
import net.minecraft.particle.ParticleTypes;
import net.minecraft.registry.tag.DamageTypeTags;
import net.minecraft.server.world.ServerWorld;
import net.minecraft.sound.SoundEvents;
import net.minecraft.util.Hand;
import net.minecraft.util.math.BlockPos;
import net.minecraft.util.math.MathHelper;
import net.minecraft.util.math.Vec3d;

public abstract class Living<T extends LivingEntity> implements Equine<T>, Caster<T>, Transmittable {
    private static final TrackedData<Optional<UUID>> CARRIER_ID = DataTracker.registerData(LivingEntity.class, TrackedDataHandlerRegistry.OPTIONAL_UUID);

    protected final T entity;

    private final EffectSync effectDelegate;

    private final Interactable sneakingHeuristic;
    private final Interactable landedHeuristic;
    private final Interactable jumpingHeuristic;

    @Nullable
    private Runnable landEvent;

    private boolean invisible = false;

    @Nullable
    private Caster<?> attacker;

    private Optional<Living<?>> target = Optional.empty();

    private int invinsibilityTicks;

    private final List<Tickable> tickers = new ArrayList<>();

    private final Enchantments enchants = addTicker(new Enchantments(this));
    private final ItemTracker armour = addTicker(new ItemTracker(this));

    protected Living(T entity, TrackedData<NbtCompound> effect) {
        this.entity = entity;
        this.effectDelegate = new EffectSync(this, effect);

        this.sneakingHeuristic = addTicker(new Interactable(entity::isSneaking));
        this.landedHeuristic = addTicker(new Interactable(entity::isOnGround));
        this.jumpingHeuristic = addTicker(new Interactable(((LivingEntityDuck)entity)::isJumping));

        entity.getDataTracker().startTracking(effect, new NbtCompound());
        entity.getDataTracker().startTracking(CARRIER_ID, Optional.empty());
    }

    public <Q extends Tickable> Q addTicker(Q tickable) {
        tickers.add(Preconditions.checkNotNull(tickable, "tickable"));
        return tickable;
    }

    public boolean isInvisible() {
        return invisible && SpellPredicate.IS_DISGUISE.isOn(this);
    }

    public void setInvisible(boolean invisible) {
        this.invisible = invisible;
    }

    public void waitForFall(Runnable action) {
        if (entity.isOnGround()) {
            action.run();
        } else {
            landEvent = action;
        }
    }

    public boolean sneakingChanged() {
        return sneakingHeuristic.hasChanged(Heuristic.ONCE);
    }

    public boolean landedChanged() {
        return landedHeuristic.hasChanged(Heuristic.ONCE);
    }

    public Interactable getJumpingHeuristic() {
        return jumpingHeuristic;
    }

    @Override
    public SpellContainer getSpellSlot() {
        return effectDelegate;
    }

    public Enchantments getEnchants() {
        return enchants;
    }

    public ItemTracker getArmour() {
        return armour;
    }

    @Override
    public final T asEntity() {
        return entity;
    }

    public Optional<UUID> getCarrierId() {
        return entity.getDataTracker().get(CARRIER_ID);
    }

    public void setCarrier(UUID carrier) {
        entity.getDataTracker().set(CARRIER_ID, Optional.ofNullable(carrier));
    }

    public void setCarrier(Entity carrier) {
        entity.getDataTracker().set(CARRIER_ID, Optional.ofNullable(carrier).map(Entity::getUuid));
    }

    @Nullable
    public Optional<Living<?>> getTarget() {
        return target;
    }

    public void setTarget(Living<?> target) {
        this.target = Optional.ofNullable(target);
    }

    public boolean isBeingCarried() {
        Entity vehicle = entity.getVehicle();
        return vehicle != null && getCarrierId().filter(vehicle.getUuid()::equals).isPresent();
    }

    @Override
    public void tick() {
        tickers.forEach(Tickable::tick);

        try {
            getSpellSlot().forEach(spell -> Operation.ofBoolean(spell.tick(this, Situation.BODY)), entity.getWorld().isClient);
        } catch (Exception e) {
            Unicopia.LOGGER.error("Error whilst ticking spell on entity {}", entity, e);
        }

        if (!(entity instanceof PlayerEntity)) {
            if (!entity.hasVehicle() && getCarrierId().isPresent() && !asWorld().isClient && entity.age % 10 == 0) {
                UUID carrierId = getCarrierId().get();
                Entity carrier = ((ServerWorld)asWorld()).getEntity(carrierId);
                if (carrier != null) {
                    asEntity().startRiding(carrier, true);
                    Living.transmitPassengers(carrier);
                } else {
                    Unicopia.LOGGER.warn("No passenger with id {]", carrierId);
                }
            }
        }

        if (invinsibilityTicks > 0) {
            invinsibilityTicks--;
        }

        if (landEvent != null && entity.isOnGround() && landedChanged()) {
            landEvent.run();
            landEvent = null;
        }

        if (entity.hasStatusEffect(UEffects.PARALYSIS) && entity.getVelocity().horizontalLengthSquared() > 0) {
            entity.setVelocity(entity.getVelocity().multiply(0, 1, 0));
            updateVelocity();
        }

        if (isBeingCarried()) {
            Pony carrier = Pony.of(entity.getVehicle()).orElse(null);
            if (!carrier.getCompositeRace().any(Abilities.CARRY::canUse)) {
                entity.stopRiding();
                entity.refreshPositionAfterTeleport(carrier.getOriginVector());
                Living.transmitPassengers(carrier.asEntity());
            }
            entity.setYaw(carrier.asEntity().getYaw());
        }

        updateDragonBreath();
    }

    public void updateAttributeModifier(UUID id, EntityAttribute attribute, float desiredValue, Float2ObjectFunction<EntityAttributeModifier> modifierSupplier, boolean permanent) {
        @Nullable
        EntityAttributeInstance instance = asEntity().getAttributeInstance(attribute);
        if (instance == null) {
            return;
        }

        @Nullable
        EntityAttributeModifier modifier = instance.getModifier(id);

        if (!MathHelper.approximatelyEquals(desiredValue, modifier == null ? 0 : modifier.getValue())) {
            if (modifier != null) {
                instance.removeModifier(modifier);
            }

            if (desiredValue != 0) {
                if (permanent) {
                    instance.addPersistentModifier(modifierSupplier.get(desiredValue));
                } else {
                    instance.addTemporaryModifier(modifierSupplier.get(desiredValue));
                }
            }
        }
    }

    public boolean canBeSeenBy(Entity entity) {
        return !isInvisible()
            && getSpellSlot()
            .get(SpellPredicate.IS_DISGUISE, true)
            .filter(spell -> spell.getDisguise().getAppearance() == entity)
            .isEmpty();
    }

    private void updateDragonBreath() {
        if (!entity.getWorld().isClient && (entity instanceof PlayerEntity || entity.hasCustomName())) {

            Vec3d targetPos = entity.getRotationVector().multiply(2).add(entity.getEyePos());

            if (entity.getWorld().isAir(BlockPos.ofFloored(targetPos))) {
                DragonBreathStore store = DragonBreathStore.get(entity.getWorld());
                String name = entity.getDisplayName().getString();
                store.popEntries(name).forEach(stack -> {
                    Vec3d randomPos = targetPos.add(VecHelper.supply(() -> entity.getRandom().nextTriangular(0.1, 0.5)));

                    if (!entity.getWorld().isAir(BlockPos.ofFloored(randomPos))) {
                        store.put(name, stack.payload());
                    }

                    for (int i = 0; i < 10; i++) {
                        ParticleUtils.spawnParticle(entity.getWorld(), ParticleTypes.FLAME, randomPos.add(
                                VecHelper.supply(() -> entity.getRandom().nextTriangular(0.1, 0.5))
                        ), Vec3d.ZERO);
                    }

                    ItemEntity item = EntityType.ITEM.create(entity.getWorld());
                    item.setStack(stack.payload());
                    item.setPosition(randomPos);
                    item.getWorld().spawnEntity(item);
                    entity.getWorld().playSoundFromEntity(null, entity, USounds.ITEM_DRAGON_BREATH_ARRIVE, entity.getSoundCategory(), 1, 1);

                    if (stack.payload().getItem() == UItems.OATS && entity instanceof PlayerEntity player) {
                        UCriteria.RECEIVE_OATS.trigger(player);
                    }
                });
            }
        }
    }

    public boolean onUpdatePassengerPosition(Entity passender, Entity.PositionUpdater positionUpdater) {
        return false;
    }

    public void onJump() {
        if (getPhysics().isGravityNegative()) {
            entity.setVelocity(entity.getVelocity().multiply(1, -1, 1));
        }
    }

    @Nullable
    public final Caster<?> getAttacker() {
        return attacker;
    }

    public Optional<Boolean> onDamage(DamageSource source, float amount) {

        if (source.isIn(DamageTypeTags.IS_LIGHTNING) && (invinsibilityTicks > 0 || tryCaptureLightning())) {
            return Optional.of(false);
        }

        if (source instanceof MagicalDamageSource magical) {
            Caster<?> attacker = ((MagicalDamageSource)source).getSpell();
            if (attacker != null) {
                this.attacker = attacker;
            }

            if (magical.isIn(UTags.BREAKS_SUNGLASSES)) {
                ItemStack glasses = GlassesItem.getForEntity(entity);
                if (glasses.getItem() == UItems.SUNGLASSES) {
                    ItemStack broken = UItems.BROKEN_SUNGLASSES.getDefaultStack();
                    broken.setNbt(glasses.getNbt());
                    TrinketsDelegate.getInstance().setEquippedStack(entity, TrinketsDelegate.FACE, broken);
                    playSound(SoundEvents.BLOCK_GLASS_BREAK, 1, 1);
                }
            }
        }

        return Optional.empty();
    }

    public Optional<BlockPos> chooseClimbingPos() {
        return getSpellSlot().get(SpellPredicate.IS_DISGUISE, false)
                .map(AbstractDisguiseSpell::getDisguise)
                .filter(EntityAppearance::canClimbWalls)
                .map(v -> entity.getBlockPos());
    }

    private boolean tryCaptureLightning() {
        return getInventoryStacks().filter(stack -> !stack.isEmpty() && stack.getItem() == UItems.EMPTY_JAR).findFirst().map(stack -> {
            invinsibilityTicks = 20;
            stack.split(1);
            giveBackItem(UItems.LIGHTNING_JAR.getDefaultStack());
            return stack;
        }).isPresent();
    }

    protected Stream<ItemStack> getInventoryStacks() {
        return Stream.of(entity.getStackInHand(Hand.MAIN_HAND), entity.getStackInHand(Hand.OFF_HAND));
    }

    protected Stream<ItemStack> getArmourStacks() {
        if (!TrinketsDelegate.hasTrinkets()) {
            return StreamSupport.stream(entity.getArmorItems().spliterator(), false);
        }
        return Stream.concat(
                TrinketsDelegate.getInstance().getEquipped(entity, TrinketsDelegate.NECKLACE),
                StreamSupport.stream(entity.getArmorItems().spliterator(), false)
        );
    }

    protected void giveBackItem(ItemStack stack) {
        entity.dropStack(stack);
    }

    @Override
    public boolean onProjectileImpact(ProjectileEntity projectile) {
        return getSpellSlot().get(true)
                .filter(effect -> !effect.isDead()
                        && effect instanceof ProjectileImpactListener
                        && ((ProjectileImpactListener)effect).onProjectileImpact(projectile))
                .isPresent();
    }

    protected void handleFall(float distance, float damageMultiplier, DamageSource cause) {
        getSpellSlot().get(SpellPredicate.IS_DISGUISE, false).ifPresent(spell -> {
            spell.getDisguise().onImpact(this, distance, damageMultiplier, cause);
        });
    }

    @Override
    public void setDirty() {}

    @Override
    public void toNBT(NbtCompound compound) {
        enchants.toNBT(compound);
        effectDelegate.toNBT(compound);
        toSyncronisedNbt(compound);
    }

    @Override
    public void fromNBT(NbtCompound compound) {
        enchants.fromNBT(compound);
        effectDelegate.fromNBT(compound);
        fromSynchronizedNbt(compound);
    }

    @Override
    public void toSyncronisedNbt(NbtCompound compound) {
        compound.put("armour", armour.toNBT());
        getCarrierId().ifPresent(id -> compound.putUuid("carrier", id));
    }

    @Override
    public void fromSynchronizedNbt(NbtCompound compound) {
        armour.fromNBT(compound.getCompound("armour"));
        setCarrier(compound.containsUuid("carrier") ? compound.getUuid("carrier") : null);
    }

    public void updateVelocity() {
        updateVelocity(entity);
    }

    public static Optional<Living<?>> getOrEmpty(Entity entity) {
        return Equine.of(entity, a -> a instanceof Living);
    }

    public static Living<?> living(Entity entity) {
        return getOrEmpty(entity).orElse(null);
    }

    public static <E extends LivingEntity> Living<E> living(E entity) {
        return Equine.<E, Living<E>>of(entity, e -> e instanceof Living<?>).orElse(null);
    }

    public static void updateVelocity(@Nullable Entity entity) {
        if (entity != null) {
            entity.velocityModified = true;
            //if (entity instanceof ServerPlayerEntity ply) {
            //    ply.networkHandler.sendPacket(new EntityVelocityUpdateS2CPacket(ply));
            //}
        }
    }

    public static void transmitPassengers(@Nullable Entity entity) {
        if (entity != null && entity.getWorld() instanceof ServerWorld sw) {
            sw.getChunkManager().sendToNearbyPlayers(entity, new EntityPassengersSetS2CPacket(entity));
        }
    }
}