package com.j256.jmx;

import javax.management.MalformedObjectNameException;
import javax.management.ObjectName;

import org.springframework.jmx.export.naming.MetadataNamingStrategy;

/**
 * Local version of the {@link MetadataNamingStrategy} which uses the {@link RuntimeJmxNames} interface to have the
 * exported object set its own name.
 * 
 * @author graywatson
 */
public class RuntimeMetadataNamingStrategy extends MetadataNamingStrategy {

	/**
	 * Overrides Spring's naming method and replaced it with our local one.
	 */
	@Override
	public ObjectName getObjectName(Object managedBean, String beanKey) throws MalformedObjectNameException {

		// get the object name from the annotation
		ObjectName objectName = super.getObjectName(managedBean, beanKey);

		// now run through and see if the object implements the naming interface
		if (managedBean instanceof RuntimeJmxNames) {
			objectName = buildObjectName((RuntimeJmxNames) managedBean, objectName.getDomain());
		}

		return objectName;
	}

	/**
	 * Construct our object name by calling the methods in {@link RuntimeJmxNames}.
	 */
	private ObjectName buildObjectName(RuntimeJmxNames namedObject, String domainName)
			throws MalformedObjectNameException {

		String[] typeNames = namedObject.getJmxPath();
		if (typeNames == null) {
			throw new MalformedObjectNameException("getJmxPath() is returning null for object " + namedObject);
		}

		StringBuilder nameBuilder = new StringBuilder();
		nameBuilder.append(domainName);
		nameBuilder.append(':');

		/*
		 * Ok. This is a HACK. It seems like something in the JMX mbean naming process actually sorts the names
		 * lexicographically. The stuff before the '=' character seems to be ignored anyway but it does look ugly.
		 */
		boolean needComma = false;
		int typeNameC = 0;
		for (String typeName : typeNames) {
			if (needComma) {
				nameBuilder.append(',');
			}
			// this will come out as 00=partition
			nameBuilder.append(String.format("%02d", typeNameC));
			typeNameC++;
			nameBuilder.append('=');
			nameBuilder.append(typeName);
			needComma = true;
		}
		if (needComma) {
			nameBuilder.append(',');
		}
		nameBuilder.append("name=");
		nameBuilder.append(namedObject.getJmxName());
		return ObjectName.getInstance(nameBuilder.toString());
	}
}