/**
 * NOTE: This copyright does *not* cover user programs that use HQ program
 * services by normal system calls through the application program interfaces
 * provided as part of the Hyperic Plug-in Development Kit or the Hyperic Client
 * Development Kit - this is merely considered normal use of the program, and
 * does *not* fall under the heading of "derived work".
 *
 * Copyright (C) [2009-2010], VMware, Inc. This file is part of HQ.
 *
 * HQ is free software; you can redistribute it and/or modify it under the terms
 * version 2 of the GNU General Public License as published by the Free Software
 * Foundation. This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
 * Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along with
 * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
 * Place, Suite 330, Boston, MA 02111-1307 USA.
 *
 */
package org.hyperic.hq.plugin.websphere;

import javax.management.AttributeNotFoundException;
import javax.management.ObjectName;
import org.hyperic.hq.product.MeasurementPlugin;
import org.hyperic.hq.product.Metric;
import org.hyperic.hq.product.MetricNotFoundException;
import org.hyperic.hq.product.MetricUnreachableException;
import org.hyperic.hq.product.MetricValue;
import org.hyperic.hq.product.PluginException;
import org.hyperic.util.config.ConfigResponse;

/**
 * MeasurementPlugin that obtains metric values via a JMX getAttribute call
 * against WebSphere's AdminClient MBeanServer wrapper
 *
 * @author Jennifer Hickey
 *
 */
public class WebsphereServiceMeasurementPlugin extends MeasurementPlugin {

    private double doubleValue(Object obj) throws PluginException {
        try {
            return Double.valueOf(obj.toString()).doubleValue();
        } catch (NumberFormatException e) {
            throw new PluginException("Cannot convert '" + obj + "' to double");
        }
    }

    @Override
    public MetricValue getValue(Metric metric) throws PluginException, MetricNotFoundException,
            MetricUnreachableException {
        double doubleVal;
        String objectName = metric.getObjectName();
        String attribute = metric.getAttributeName();
        Object objectVal = null;
        try {
            ObjectName objName = new ObjectName(objectName);
            objectVal = WebsphereUtil.getMBeanServer(metric).getAttribute(objName, attribute);
        } catch (AttributeNotFoundException e) {
            // XXX not all MBeans have a reasonable attribute to
            // determine availability, so just assume if we get this far
            // the MBean exists and is alive.
            if (metric.isAvail()) {
                objectVal = new Double(Metric.AVAIL_UP);
            } else {
                throw new PluginException(e);
            }
        } catch (RuntimeException e) {
            // Temporary fix until availability strings can be mapped
            // in hq-plugin.xml. Resin wraps AttributeNotFoundException
            if (metric.isAvail()) {
                Throwable cause = e.getCause();
                while (cause != null) {
                    if (cause instanceof AttributeNotFoundException) {
                        objectVal = new Double(Metric.AVAIL_UP);
                        break;
                    }
                    cause = cause.getCause();
                }
                if (objectVal == null) {
                    objectVal = new Double(Metric.AVAIL_DOWN);
                }
            } else {
                throw e;
            }
        } catch (Exception e) {
            if (metric.isAvail()) {
                objectVal = new Double(Metric.AVAIL_DOWN);
            } else {
                throw new PluginException("Unable to obtain the value of metric: " + metric.getObjectName()
                        + ".  Cause: " + e.getMessage());
            }
        }

        String stringVal = objectVal.toString();

        // check for value mappings in plugin.xml:
        // <property name"StateVal.Stopped" value="0.0"/>
        // <property name="StateVal.Started" value="1.0"/>
        // <property name"State.3" value="1.0"/>
        String mappedVal = getTypeProperty(metric.getAttributeName() + "." + stringVal);

        if (mappedVal != null) {
            doubleVal = doubleValue(mappedVal);
        } else if (objectVal instanceof Number) {
            doubleVal = ((Number) objectVal).doubleValue();
        } else if (objectVal instanceof Boolean) {
            doubleVal = ((Boolean) objectVal).booleanValue() ? Metric.AVAIL_UP : Metric.AVAIL_DOWN;
        } else {
            doubleVal = doubleValue(stringVal);
        }

        if (doubleVal == -1) {
            return new MetricValue(Double.NaN);
        }

        return new MetricValue(doubleVal);
    }

    @Override
    public String translate(String template, ConfigResponse config) {
        return super.translate(template, config);
    }
}