package org.bukkit.entity;

import java.util.Collection;
import java.util.HashSet;
import java.util.List;

import org.bukkit.Location;
import org.bukkit.block.Block;
import org.bukkit.inventory.EntityEquipment;
import org.bukkit.potion.PotionEffect;
import org.bukkit.potion.PotionEffectType;

/**
 * Represents a living entity, such as a monster or player
 */
public interface LivingEntity extends Entity, Damageable {
    /**
     * Gets the height of the entity's head above its Location
     *
     * @return Height of the entity's eyes above its Location
     */
    public double getEyeHeight();

    /**
     * Gets the height of the entity's head above its Location
     *
     * @param ignoreSneaking If set to true, the effects of sneaking will be ignored
     * @return Height of the entity's eyes above its Location
     */
    public double getEyeHeight(boolean ignoreSneaking);

    /**
     * Get a Location detailing the current eye position of the LivingEntity.
     *
     * @return a Location at the eyes of the LivingEntity.
     */
    public Location getEyeLocation();

    /**
     * Gets all blocks along the player's line of sight
     * List iterates from player's position to target inclusive
     *
     * @param transparent HashSet containing all transparent block IDs. If set to null only air is considered transparent.
     * @param maxDistance This is the maximum distance to scan. This may be further limited by the server, but never to less than 100 blocks.
     * @return List containing all blocks along the player's line of sight
     */
    public List<Block> getLineOfSight(HashSet<Byte> transparent, int maxDistance);

    /**
     * Gets the block that the player has targeted
     *
     * @param transparent HashSet containing all transparent block IDs. If set to null only air is considered transparent.
     * @param maxDistance This is the maximum distance to scan. This may be further limited by the server, but never to less than 100 blocks.
     * @return Block that the player has targeted
     */
    public Block getTargetBlock(HashSet<Byte> transparent, int maxDistance);

    /**
     * Gets the last two blocks along the player's line of sight.
     * The target block will be the last block in the list.
     *
     * @param transparent HashSet containing all transparent block IDs. If set to null only air is considered transparent.
     * @param maxDistance This is the maximum distance to scan. This may be further limited by the server, but never to less than 100 blocks
     * @return List containing the last 2 blocks along the player's line of sight
     */
    public List<Block> getLastTwoTargetBlocks(HashSet<Byte> transparent, int maxDistance);

    /**
     * Throws an egg from the entity.
     *
     * @deprecated Use launchProjectile(Egg.class) instead
     * @return The egg thrown.
     */
    @Deprecated
    public Egg throwEgg();

    /**
     * Throws a snowball from the entity.
     *
     * @deprecated Use launchProjectile(Snowball.class) instead
     * @return The snowball thrown.
     */
    @Deprecated
    public Snowball throwSnowball();

    /**
     * Shoots an arrow from the entity.
     *
     * @deprecated Use launchProjectile(Arrow.class) instead
     * @return The arrow shot.
     */
    @Deprecated
    public Arrow shootArrow();

    /**
     * Launches a {@link Projectile} from the entity.
     *
     * @param projectile Class of the projectile to launch
     *
     * @return The launched projectile.
     */
    public <T extends Projectile> T launchProjectile(Class<? extends T> projectile);

    /**
     * Returns the amount of air that this entity has remaining, in ticks
     *
     * @return Amount of air remaining
     */
    public int getRemainingAir();

    /**
     * Sets the amount of air that this entity has remaining, in ticks
     *
     * @param ticks Amount of air remaining
     */
    public void setRemainingAir(int ticks);

    /**
     * Returns the maximum amount of air this entity can have, in ticks
     *
     * @return Maximum amount of air
     */
    public int getMaximumAir();

    /**
     * Sets the maximum amount of air this entity can have, in ticks
     *
     * @param ticks Maximum amount of air
     */
    public void setMaximumAir(int ticks);

    /**
     * Returns the entities current maximum noDamageTicks
     * This is the time in ticks the entity will become unable to take
     * equal or less damage than the lastDamage
     *
     * @return noDamageTicks
     */
    public int getMaximumNoDamageTicks();

    /**
     * Sets the entities current maximum noDamageTicks
     *
     * @param ticks maximumNoDamageTicks
     */
    public void setMaximumNoDamageTicks(int ticks);

    /**
     * Returns the entities lastDamage taken in the current noDamageTicks time.
     * Only damage higher than this amount will further damage the entity.
     *
     * @return lastDamage
     */
    public int getLastDamage();

    /**
     * Sets the entities current maximum noDamageTicks
     *
     * @param damage last damage
     */
    public void setLastDamage(int damage);

    /**
     * Returns the entities current noDamageTicks
     *
     * @return noDamageTicks
     */
    public int getNoDamageTicks();

    /**
     * Sets the entities current noDamageTicks
     *
     * @param ticks NoDamageTicks
     */
    public void setNoDamageTicks(int ticks);

    /**
     * Gets the player identified as the killer of this entity.
     * <p />
     * May be null.
     *
     * @return Killer player, or null if none found.
     */
    public Player getKiller();

    /**
     * Adds the given {@link PotionEffect} to this entity.
     * Only one potion effect can be present for a given {@link PotionEffectType}.
     *
     * @param effect PotionEffect to be added
     * @return Whether the effect could be added
     */
    public boolean addPotionEffect(PotionEffect effect);

    /**
     * Adds the given {@link PotionEffect} to this entity.
     * Only one potion effect can be present for a given {@link PotionEffectType}.
     *
     * @param effect PotionEffect to be added
     * @param force Whether conflicting effects should be removed
     * @return Whether the effect could be added
     */
    public boolean addPotionEffect(PotionEffect effect, boolean force);

    /**
     * Attempts to add all of the given {@link PotionEffect} to this entity.
     *
     * @param effects The effects to add
     * @return Whether all of the effects could be added
     */
    public boolean addPotionEffects(Collection<PotionEffect> effects);

    /**
     * Returns whether the entity already has an existing
     * effect of the given {@link PotionEffectType} applied to it.
     *
     * @param type The potion type to check
     * @return Whether the player has this potion effect active on them.
     */
    public boolean hasPotionEffect(PotionEffectType type);

    /**
     * Removes any effects present of the given {@link PotionEffectType}.
     *
     * @param type The potion type to remove
     */
    public void removePotionEffect(PotionEffectType type);

    /**
     * Returns all currently active {@link PotionEffect}s on this entity.
     *
     * @return A collection of {@link PotionEffect}s
     */
    public Collection<PotionEffect> getActivePotionEffects();

    /**
     * Checks whether the entity has block line of sight to another.<br />
     * This uses the same algorithm that hostile mobs use to find the closest player.
     *
     * @param other The entity to determine line of sight to.
     * @return true if there is a line of sight, false if not.
     */
    public boolean hasLineOfSight(Entity other);

    /**
     * Returns if the entity despawns when away from players or not.<br />
     * By default animals are not removed while other mobs are.
     *
     * @return true if the entity is removed when away from players
     */
    public boolean getRemoveWhenFarAway();

    /**
     * Sets whether or not the entity despawns when away from players or not.
     *
     * @param remove The remove status
     */
    public void setRemoveWhenFarAway(boolean remove);

    /**
     *  Gets the inventory with the equipment worn by this entity.
     *
     *  @return the entities inventory.
     */
    public EntityEquipment getEquipment();

    /**
     * Sets whether or not the entity can pick up items
     *
     * @param pickup Whether or not the entity can pick up items
     */
    public void setCanPickupItems(boolean pickup);

    /**
     * Gets if the entity can pick up items
     *
     * @return whether or not the entity can pick up items
     */
    public boolean getCanPickupItems();

    /**
     * Sets a custom name on a mob. This name will be used in death messages
     * and can be sent to the client as a nameplate over the mob.
     * <p>
     * Setting the name to null or an empty string will clear it.
     * <p>
     * This value has no effect on players, they will always use their real
     * name.
     * @param name name to set
     */
    public void setCustomName(String name);

    /**
     * Gets the custom name on a mob. If there is no name this method will
     * return null.
     * <p>
     * This value has no effect on players, they will always use their real
     * name.
     * @return name of the mob or null
     */
    public String getCustomName();

    /**
     * Sets whether or not to display the mob's custom name client side.
     * The name will be displayed above the mob similarly to a player.
     * <p>
     * This value has no effect on players, they will always display their
     * name.
     * @param flag show custom name
     */
    public void setCustomNameVisible(boolean flag);

    /**
     * Gets whether or not the mob's custom name is displayed client side.
     * <p>
     * This value has no effect on players, they will always display their
     * name.
     * @return if the custom name is displayed
     */
    public boolean isCustomNameVisible();
}