/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.servicemix.jbi.management;

import java.beans.PropertyChangeEvent;
import java.beans.PropertyChangeListener;
import java.beans.PropertyDescriptor;
import java.lang.reflect.InvocationTargetException;
import java.util.Date;
import java.util.Hashtable;
import java.util.LinkedHashMap;
import java.util.Map;
import java.util.concurrent.ExecutorService;

import javax.management.Attribute;
import javax.management.AttributeChangeNotification;
import javax.management.AttributeChangeNotificationFilter;
import javax.management.AttributeList;
import javax.management.AttributeNotFoundException;
import javax.management.Descriptor;
import javax.management.InvalidAttributeValueException;
import javax.management.ListenerNotFoundException;
import javax.management.MBeanAttributeInfo;
import javax.management.MBeanException;
import javax.management.MBeanInfo;
import javax.management.MBeanNotificationInfo;
import javax.management.MBeanOperationInfo;
import javax.management.MBeanRegistration;
import javax.management.MBeanServer;
import javax.management.NotCompliantMBeanException;
import javax.management.Notification;
import javax.management.NotificationBroadcasterSupport;
import javax.management.NotificationFilter;
import javax.management.NotificationListener;
import javax.management.ObjectName;
import javax.management.ReflectionException;
import javax.management.RuntimeOperationsException;
import javax.management.StandardMBean;
import javax.management.modelmbean.DescriptorSupport;
import javax.management.modelmbean.ModelMBeanNotificationBroadcaster;
import javax.management.modelmbean.ModelMBeanNotificationInfo;

import org.apache.commons.beanutils.MethodUtils;
import org.apache.commons.beanutils.PropertyUtilsBean;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

/**
 * An MBean wrapper for an Existing Object
 * 
 * @version $Revision: 570136 $
 */
public class BaseStandardMBean extends StandardMBean implements ModelMBeanNotificationBroadcaster, MBeanRegistration,
                PropertyChangeListener {

    private static final Log LOG = LogFactory.getLog(BaseStandardMBean.class);

    private static final Map<String, Class<?>> PRIMITIVE_CLASSES = new Hashtable<String, Class<?>>(8);
    {
        PRIMITIVE_CLASSES.put(Boolean.TYPE.toString(), Boolean.TYPE);
        PRIMITIVE_CLASSES.put(Character.TYPE.toString(), Character.TYPE);
        PRIMITIVE_CLASSES.put(Byte.TYPE.toString(), Byte.TYPE);
        PRIMITIVE_CLASSES.put(Short.TYPE.toString(), Short.TYPE);
        PRIMITIVE_CLASSES.put(Integer.TYPE.toString(), Integer.TYPE);
        PRIMITIVE_CLASSES.put(Long.TYPE.toString(), Long.TYPE);
        PRIMITIVE_CLASSES.put(Float.TYPE.toString(), Float.TYPE);
        PRIMITIVE_CLASSES.put(Double.TYPE.toString(), Double.TYPE);
    }

    protected ExecutorService executorService;

    private Map<String, CachedAttribute> cachedAttributes = new LinkedHashMap<String, CachedAttribute>();

    // used to maintain insertion ordering
    private PropertyUtilsBean beanUtil = new PropertyUtilsBean();

    private NotificationBroadcasterSupport broadcasterSupport = new NotificationBroadcasterSupport();

    private MBeanAttributeInfo[] attributeInfos;

    private MBeanInfo beanInfo;

    // this values are set after registering with the MBeanServer//
    private ObjectName objectName;

    private MBeanServer beanServer;

    /**
     * Constructor
     * 
     * @param object
     * @param interfaceMBean
     * @param description
     * @param attrs
     * @param ops
     * @param executorService2
     * @throws ReflectionException
     * @throws NotCompliantMBeanException
     */
    public BaseStandardMBean(Object object, Class interfaceMBean, String description, 
                             MBeanAttributeInfo[] attrs, MBeanOperationInfo[] ops,
                             ExecutorService executorService) throws ReflectionException, NotCompliantMBeanException {
        super(object, interfaceMBean);
        this.attributeInfos = attrs;
        buildAttributes(object, this.attributeInfos);
        this.beanInfo = new MBeanInfo(object.getClass().getName(), description, attrs, null, ops, getNotificationInfo());
        this.executorService = executorService;
    }

    /**
     * @return the MBeanINfo for this MBean
     */
    public MBeanInfo getMBeanInfo() {
        return beanInfo;
    }

    /**
     * Retrieve ObjectName of the MBean - set after registration
     * 
     * @return the ObjectName of the MBean
     */
    public ObjectName getObjectName() {
        return objectName;
    }

    /**
     * Retrieve the MBeanServer - set after registration
     * 
     * @return the beanServer
     */
    public MBeanServer getBeanServer() {
        return beanServer;
    }

    /**
     * Get the Value of an Attribute
     * 
     * @param name
     * @return the value of the Attribute
     * @throws AttributeNotFoundException
     * @throws MBeanException
     * @throws ReflectionException
     */
    public Object getAttribute(String name) throws AttributeNotFoundException, MBeanException, ReflectionException {
        Object result = null;
        CachedAttribute ca = cachedAttributes.get(name);
        if (ca == null) {
            // the use of proxies in MX4J has a bug - in which the caps can be
            // changed on
            // an attribute
            for (Map.Entry<String, CachedAttribute> entry : cachedAttributes.entrySet()) {
                String key = entry.getKey();
                if (key.equalsIgnoreCase(name)) {
                    ca = entry.getValue();
                    break;
                }
            }
        }
        if (ca != null) {
            result = getCurrentValue(ca);
        } else {
            throw new AttributeNotFoundException("Could not locate " + name);
        }
        return result;
    }

    /**
     * Set the Attribute
     * 
     * @param attr
     * @throws AttributeNotFoundException
     * @throws InvalidAttributeValueException
     * @throws MBeanException
     * @throws ReflectionException
     */
    public void setAttribute(Attribute attr) throws AttributeNotFoundException, InvalidAttributeValueException, MBeanException,
                    ReflectionException {
        String name = attr.getName();
        CachedAttribute ca = cachedAttributes.get(name);
        if (ca != null) {
            Attribute old = ca.getAttribute();
            try {
                ca.updateAttribute(beanUtil, attr);
                sendAttributeChangeNotification(old, attr);
            } catch (NoSuchMethodException e) {
                throw new ReflectionException(e);
            } catch (IllegalAccessException e) {
                throw new ReflectionException(e);
            } catch (InvocationTargetException e) {
                Throwable t = e.getTargetException();
                if (t instanceof Exception) {
                    throw new MBeanException(e);
                }
                throw new MBeanException(e);
            }
        } else {
            throw new AttributeNotFoundException("Could not locate " + name);
        }
    }

    /**
     * Update a named attribute
     * 
     * @param name
     * @param value
     */
    public void updateAttribute(String name, Object value) {
        CachedAttribute ca = cachedAttributes.get(name);
        if (ca != null) {
            Attribute old = ca.getAttribute();
            ca.updateAttributeValue(value);
            try {
                sendAttributeChangeNotification(old, ca.getAttribute());
            } catch (RuntimeOperationsException e) {
                LOG.error("Failed to update attribute: " + name + " to new value: " + value, e);
            } catch (MBeanException e) {
                LOG.error("Failed to update attribute: " + name + " to new value: " + value, e);
            }
        }
    }

    /**
     * Attribute change - fire notification
     * 
     * @param event
     */
    public void propertyChange(PropertyChangeEvent event) {
        updateAttribute(event.getPropertyName(), event.getNewValue());
    }

    /**
     * @param attributes -
     *            array of Attribute names
     * @return AttributeList of matching Attributes
     */
    public AttributeList getAttributes(String[] attributes) {
        AttributeList result = null;
        try {
            if (attributes != null) {
                result = new AttributeList();
                for (int i = 0; i < attributes.length; i++) {
                    CachedAttribute ca = cachedAttributes.get(attributes[i]);
                    ca.updateValue(beanUtil);
                    result.add(ca.getAttribute());
                }
            } else {
                // Do this to maintain insertion ordering
                for (Map.Entry<String, CachedAttribute> entry : cachedAttributes.entrySet()) {
                    CachedAttribute ca = entry.getValue();
                    ca.updateValue(beanUtil);
                    result.add(ca.getAttribute());
                }
            }
        } catch (MBeanException e) {
            LOG.error("Caught excdeption building attributes", e);
        }
        return result;
    }

    /**
     * Set values of Attributes
     * 
     * @param attributes
     * @return the list of Attributes set with their new values
     */
    public AttributeList setAttributes(AttributeList attributes) {
        AttributeList result = new AttributeList();
        if (attributes != null) {
            for (int i = 0; i < attributes.size(); i++) {
                Attribute attribute = (Attribute) attributes.get(i);
                try {
                    setAttribute(attribute);
                } catch (AttributeNotFoundException e) {
                    LOG.warn("Failed to setAttribute(" + attribute + ")", e);
                } catch (InvalidAttributeValueException e) {
                    LOG.warn("Failed to setAttribute(" + attribute + ")", e);
                } catch (MBeanException e) {
                    LOG.warn("Failed to setAttribute(" + attribute + ")", e);
                } catch (ReflectionException e) {
                    LOG.warn("Failed to setAttribute(" + attribute + ")", e);
                }
                result.add(attribute);
            }
        }
        return result;
    }

    /**
     * Invoke an operation
     * 
     * @param name
     * @param params
     * @param signature
     * @return result of invoking an operation
     * @throws MBeanException
     * @throws ReflectionException
     */
    public Object invoke(String name, Object[] params, String[] signature) throws MBeanException, ReflectionException {
        ClassLoader oldCl = Thread.currentThread().getContextClassLoader();
        try {
            Class<?>[] parameterTypes = new Class<?>[signature.length];
            for (int i = 0; i < parameterTypes.length; i++) {
                parameterTypes[i] = PRIMITIVE_CLASSES.get(signature[i]);
                if (parameterTypes[i] == null) {
                    parameterTypes[i] = Class.forName(signature[i]);
                }
            }
            Thread.currentThread().setContextClassLoader(getImplementation().getClass().getClassLoader());
            return MethodUtils.invokeMethod(getImplementation(), name, params, parameterTypes);
        } catch (ClassNotFoundException e) {
            throw new ReflectionException(e);
        } catch (NoSuchMethodException e) {
            throw new ReflectionException(e);
        } catch (IllegalAccessException e) {
            throw new ReflectionException(e);
        } catch (InvocationTargetException e) {
            Throwable t = e.getTargetException();
            if (t instanceof Exception) {
                throw new MBeanException((Exception) t);
            } else {
                throw new MBeanException(e);
            }
        } finally {
            Thread.currentThread().setContextClassLoader(oldCl);
        }
    }

    /**
     * Called at registration
     * 
     * @param mbs
     * @param on
     * @return the ObjectName
     * @throws Exception
     */
    public ObjectName preRegister(MBeanServer mbs, ObjectName on) throws Exception {
        if (mbs != null) {
            this.beanServer = mbs;
        }
        if (on != null) {
            this.objectName = on;
        }
        return on;
    }

    /**
     * Caled post registration
     * 
     * @param done
     */
    public void postRegister(Boolean done) {
    }

    /**
     * Called before removal from the MBeanServer
     * 
     * @throws Exception
     */
    public void preDeregister() throws Exception {
    }

    /**
     * Called after removal from the MBeanServer
     */
    public void postDeregister() {
    }

    /**
     * @param notification
     * @throws MBeanException
     * @throws RuntimeOperationsException
     */
    public void sendNotification(final Notification notification) throws MBeanException, RuntimeOperationsException {
        if (notification != null && !executorService.isShutdown()) {
            executorService.execute(new Runnable() {
                public void run() {
                    broadcasterSupport.sendNotification(notification);
                }
            });
        }
    }

    /**
     * @param text
     * @throws MBeanException
     * @throws RuntimeOperationsException
     */
    public void sendNotification(String text) throws MBeanException, RuntimeOperationsException {
        if (text != null) {
            Notification myNtfyObj = new Notification("jmx.modelmbean.generic", this, 1, text);
            sendNotification(myNtfyObj);
        }
    }

    /**
     * @param l
     * @param attrName
     * @param handback
     * @throws MBeanException
     * @throws RuntimeOperationsException
     * @throws IllegalArgumentException
     */
    public void addAttributeChangeNotificationListener(NotificationListener l, String attrName, Object handback) throws MBeanException,
                    RuntimeOperationsException, IllegalArgumentException {
        AttributeChangeNotificationFilter currFilter = new AttributeChangeNotificationFilter();
        currFilter.enableAttribute(attrName);
        broadcasterSupport.addNotificationListener(l, currFilter, handback);
    }

    /**
     * @param l
     * @param attrName
     * @throws MBeanException
     * @throws RuntimeOperationsException
     * @throws ListenerNotFoundException
     */
    public void removeAttributeChangeNotificationListener(NotificationListener l, String attrName) throws MBeanException,
                    RuntimeOperationsException, ListenerNotFoundException {
        broadcasterSupport.removeNotificationListener(l);
    }

    /**
     * @param notification
     * @throws MBeanException
     * @throws RuntimeOperationsException
     */
    public void sendAttributeChangeNotification(AttributeChangeNotification notification) throws MBeanException, 
                                                                                                 RuntimeOperationsException {
        sendNotification(notification);
    }

    /**
     * @param oldAttr
     * @param newAttr
     * @throws MBeanException
     * @throws RuntimeOperationsException
     */
    public void sendAttributeChangeNotification(Attribute oldAttr, Attribute newAttr) throws MBeanException, RuntimeOperationsException {
        if (!oldAttr.equals(newAttr)) {
            AttributeChangeNotification notification = new AttributeChangeNotification(objectName, 1, (new Date()).getTime(),
                            "AttributeChange", oldAttr.getName(), newAttr.getValue().getClass().toString(), oldAttr.getValue(),
                            newAttr.getValue());
            sendAttributeChangeNotification(notification);
        }
    }

    /**
     * @return notificationInfo
     */
    public final MBeanNotificationInfo[] getNotificationInfo() {
        MBeanNotificationInfo[] result = new MBeanNotificationInfo[2];
        Descriptor genericDescriptor = new DescriptorSupport(new String[] {
            "name=GENERIC", "descriptorType=notification", "log=T",
            "severity=5", "displayName=jmx.modelmbean.generic" });
        result[0] = new ModelMBeanNotificationInfo(new String[] {"jmx.modelmbean.generic" }, "GENERIC",
            "A text notification has been issued by the managed resource", genericDescriptor);
        Descriptor attributeDescriptor = new DescriptorSupport(new String[] {"name=ATTRIBUTE_CHANGE", "descriptorType=notification",
            "log=T", "severity=5", "displayName=jmx.attribute.change" });
        result[1] = new ModelMBeanNotificationInfo(new String[] {"jmx.attribute.change" }, "ATTRIBUTE_CHANGE",
            "Signifies that an observed MBean attribute value has changed", attributeDescriptor);
        return result;
    }

    /**
     * @param l
     * @param filter
     * @param handle
     * @throws IllegalArgumentException
     */
    public void addNotificationListener(NotificationListener l, NotificationFilter filter, 
                                        Object handle) throws IllegalArgumentException {
        broadcasterSupport.addNotificationListener(l, filter, handle);
    }

    /**
     * @param l
     * @throws ListenerNotFoundException
     */
    public void removeNotificationListener(NotificationListener l) throws ListenerNotFoundException {
        broadcasterSupport.removeNotificationListener(l);
    }

    private Object getCurrentValue(CachedAttribute ca) throws MBeanException {
        Object result = null;
        if (ca != null) {
            try {
                result = beanUtil.getProperty(ca.getBean(), ca.getName());
            } catch (IllegalAccessException e) {
                throw new MBeanException(e);
            } catch (InvocationTargetException e) {
                throw new MBeanException(e);
            } catch (NoSuchMethodException e) {
                throw new MBeanException(e);
            }
        }
        return result;
    }

    /**
     * build internal Map of CachedAttributes
     * 
     * @param obj
     * @param attrs
     * @throws ReflectionException
     */
    private void buildAttributes(Object obj, MBeanAttributeInfo[] attrs) throws ReflectionException {
        if (attrs != null) {
            for (int i = 0; i < attrs.length; i++) {
                try {
                    String name = attrs[i].getName();
                    PropertyDescriptor pd = beanUtil.getPropertyDescriptor(obj, name);
                    Object value = beanUtil.getProperty(obj, name);
                    Attribute attribute = new Attribute(name, value);
                    CachedAttribute ca = new CachedAttribute(attribute);
                    ca.setBean(obj);
                    ca.setPropertyDescriptor(pd);
                    cachedAttributes.put(name, ca);
                } catch (NoSuchMethodException e) {
                    throw new ReflectionException(e);
                } catch (IllegalAccessException e) {
                    throw new ReflectionException(e);
                } catch (InvocationTargetException e) {
                    throw new ReflectionException(e);
                }
            }
        }
    }
}
