package org.bukkit.metadata;

import org.apache.commons.lang.Validate;
import org.bukkit.plugin.Plugin;
import org.bukkit.util.NumberConversions;

import java.lang.ref.WeakReference;

/**
 * Optional base class for facilitating MetadataValue implementations.
 * <p>
 * This provides all the conversion functions for MetadataValue so that
 * writing an implementation of MetadataValue is as simple as implementing
 * value() and invalidate().
 */
public abstract class MetadataValueAdapter implements MetadataValue
{
	protected final WeakReference<Plugin> owningPlugin;

	protected MetadataValueAdapter(Plugin owningPlugin)
	{
		Validate.notNull(owningPlugin, "owningPlugin cannot be null");
		this.owningPlugin = new WeakReference<Plugin>(owningPlugin);
	}

	public Plugin getOwningPlugin()
	{
		return owningPlugin.get();
	}

	public int asInt()
	{
		return NumberConversions.toInt(value());
	}

	public float asFloat()
	{
		return NumberConversions.toFloat(value());
	}

	public double asDouble()
	{
		return NumberConversions.toDouble(value());
	}

	public long asLong()
	{
		return NumberConversions.toLong(value());
	}

	public short asShort()
	{
		return NumberConversions.toShort(value());
	}

	public byte asByte()
	{
		return NumberConversions.toByte(value());
	}

	public boolean asBoolean()
	{
		Object value = value();
		if(value instanceof Boolean)
		{
			return (Boolean) value;
		}

		if(value instanceof Number)
		{
			return ((Number) value).intValue() != 0;
		}

		if(value instanceof String)
		{
			return Boolean.parseBoolean((String) value);
		}

		return value != null;
	}

	public String asString()
	{
		Object value = value();

		if(value == null)
		{
			return "";
		}
		return value.toString();
	}

}