package org.bukkit.enchantments;

import org.bukkit.command.defaults.EnchantCommand;
import org.bukkit.inventory.ItemStack;

import java.util.HashMap;
import java.util.Map;

/**
 * The various type of enchantments that may be added to armour or weapons
 */
public abstract class Enchantment
{
	/**
	 * Provides protection against environmental damage
	 */
	public static final Enchantment PROTECTION_ENVIRONMENTAL = new EnchantmentWrapper(0);

	/**
	 * Provides protection against fire damage
	 */
	public static final Enchantment PROTECTION_FIRE = new EnchantmentWrapper(1);

	/**
	 * Provides protection against fall damage
	 */
	public static final Enchantment PROTECTION_FALL = new EnchantmentWrapper(2);

	/**
	 * Provides protection against explosive damage
	 */
	public static final Enchantment PROTECTION_EXPLOSIONS = new EnchantmentWrapper(3);

	/**
	 * Provides protection against projectile damage
	 */
	public static final Enchantment PROTECTION_PROJECTILE = new EnchantmentWrapper(4);

	/**
	 * Decreases the rate of air loss whilst underwater
	 */
	public static final Enchantment OXYGEN = new EnchantmentWrapper(5);

	/**
	 * Increases the speed at which a player may mine underwater
	 */
	public static final Enchantment WATER_WORKER = new EnchantmentWrapper(6);

	/**
	 * Damages the attacker
	 */
	public static final Enchantment THORNS = new EnchantmentWrapper(7);

	/**
	 * Increases damage against all targets
	 */
	public static final Enchantment DAMAGE_ALL = new EnchantmentWrapper(16);

	/**
	 * Increases damage against undead targets
	 */
	public static final Enchantment DAMAGE_UNDEAD = new EnchantmentWrapper(17);

	/**
	 * Increases damage against arthropod targets
	 */
	public static final Enchantment DAMAGE_ARTHROPODS = new EnchantmentWrapper(18);

	/**
	 * All damage to other targets will knock them back when hit
	 */
	public static final Enchantment KNOCKBACK = new EnchantmentWrapper(19);

	/**
	 * When attacking a target, has a chance to set them on fire
	 */
	public static final Enchantment FIRE_ASPECT = new EnchantmentWrapper(20);

	/**
	 * Provides a chance of gaining extra loot when killing monsters
	 */
	public static final Enchantment LOOT_BONUS_MOBS = new EnchantmentWrapper(21);

	/**
	 * Increases the rate at which you mine/dig
	 */
	public static final Enchantment DIG_SPEED = new EnchantmentWrapper(32);

	/**
	 * Allows blocks to drop themselves instead of fragments (for example,
	 * stone instead of cobblestone)
	 */
	public static final Enchantment SILK_TOUCH = new EnchantmentWrapper(33);

	/**
	 * Decreases the rate at which a tool looses durability
	 */
	public static final Enchantment DURABILITY = new EnchantmentWrapper(34);

	/**
	 * Provides a chance of gaining extra loot when destroying blocks
	 */
	public static final Enchantment LOOT_BONUS_BLOCKS = new EnchantmentWrapper(35);

	/**
	 * Provides extra damage when shooting arrows from bows
	 */
	public static final Enchantment ARROW_DAMAGE = new EnchantmentWrapper(48);

	/**
	 * Provides a knockback when an entity is hit by an arrow from a bow
	 */
	public static final Enchantment ARROW_KNOCKBACK = new EnchantmentWrapper(49);

	/**
	 * Sets entities on fire when hit by arrows shot from a bow
	 */
	public static final Enchantment ARROW_FIRE = new EnchantmentWrapper(50);

	/**
	 * Provides infinite arrows when shooting a bow
	 */
	public static final Enchantment ARROW_INFINITE = new EnchantmentWrapper(51);

	/**
	 * Decreases odds of catching worthless junk
	 */
	public static final Enchantment LUCK = new EnchantmentWrapper(61);

	/**
	 * Increases rate of fish biting your hook
	 */
	public static final Enchantment LURE = new EnchantmentWrapper(62);

	private static final Map<Integer, Enchantment> byId = new HashMap<Integer, Enchantment>();
	private static final Map<String, Enchantment> byName = new HashMap<String, Enchantment>();
	private static boolean acceptingNew = true;
	private final int id;

	public Enchantment(int id)
	{
		this.id = id;
	}

	/**
	 * Gets the unique ID of this enchantment
	 *
	 * @return Unique ID
	 * @deprecated Magic value
	 */
	@Deprecated
	public int getId()
	{
		return id;
	}

	/**
	 * Gets the unique name of this enchantment
	 *
	 * @return Unique name
	 */
	public abstract String getName();

	/**
	 * Gets the maximum level that this Enchantment may become.
	 *
	 * @return Maximum level of the Enchantment
	 */
	public abstract int getMaxLevel();

	/**
	 * Gets the level that this Enchantment should start at
	 *
	 * @return Starting level of the Enchantment
	 */
	public abstract int getStartLevel();

	/**
	 * Gets the type of {@link ItemStack} that may fit this Enchantment.
	 *
	 * @return Target type of the Enchantment
	 */
	public abstract EnchantmentTarget getItemTarget();

	/**
	 * Check if this enchantment conflicts with another enchantment.
	 *
	 * @param other The enchantment to check against
	 * @return True if there is a conflict.
	 */
	public abstract boolean conflictsWith(Enchantment other);

	/**
	 * Checks if this Enchantment may be applied to the given {@link
	 * ItemStack}.
	 * <p>
	 * This does not check if it conflicts with any enchantments already
	 * applied to the item.
	 *
	 * @param item Item to test
	 * @return True if the enchantment may be applied, otherwise False
	 */
	public abstract boolean canEnchantItem(ItemStack item);

	@Override
	public boolean equals(Object obj)
	{
		if(obj == null)
		{
			return false;
		}
		if(!(obj instanceof Enchantment))
		{
			return false;
		}
		final Enchantment other = (Enchantment) obj;
		if(this.id != other.id)
		{
			return false;
		}
		return true;
	}

	@Override
	public int hashCode()
	{
		return id;
	}

	@Override
	public String toString()
	{
		return "Enchantment[" + id + ", " + getName() + "]";
	}

	/**
	 * Registers an enchantment with the given ID and object.
	 * <p>
	 * Generally not to be used from within a plugin.
	 *
	 * @param enchantment Enchantment to register
	 */
	public static void registerEnchantment(Enchantment enchantment)
	{
		if(byId.containsKey(enchantment.id) || byName.containsKey(enchantment.getName()))
		{
			throw new IllegalArgumentException("Cannot set already-set enchantment");
		}
		else if(!isAcceptingRegistrations())
		{
			throw new IllegalStateException("No longer accepting new enchantments (can only be done by the server implementation)");
		}

		byId.put(enchantment.id, enchantment);
		byName.put(enchantment.getName(), enchantment);
	}

	/**
	 * Checks if this is accepting Enchantment registrations.
	 *
	 * @return True if the server Implementation may add enchantments
	 */
	public static boolean isAcceptingRegistrations()
	{
		return acceptingNew;
	}

	/**
	 * Stops accepting any enchantment registrations
	 */
	public static void stopAcceptingRegistrations()
	{
		acceptingNew = false;
		EnchantCommand.buildEnchantments();
	}

	/**
	 * Gets the Enchantment at the specified ID
	 *
	 * @param id ID to fetch
	 * @return Resulting Enchantment, or null if not found
	 * @deprecated Magic value
	 */
	@Deprecated
	public static Enchantment getById(int id)
	{
		return byId.get(id);
	}

	/**
	 * Gets the Enchantment at the specified name
	 *
	 * @param name Name to fetch
	 * @return Resulting Enchantment, or null if not found
	 */
	public static Enchantment getByName(String name)
	{
		return byName.get(name);
	}

	/**
	 * Gets an array of all the registered {@link Enchantment}s
	 *
	 * @return Array of enchantments
	 */
	public static Enchantment[] values()
	{
		return byId.values().toArray(new Enchantment[byId.size()]);
	}
}