/*************************************************************************
 * Copyright 2009-2016 Eucalyptus Systems, Inc.
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; version 3 of the License.
 *
 * 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, see http://www.gnu.org/licenses/.
 *
 * Please contact Eucalyptus Systems, Inc., 6755 Hollister Ave., Goleta
 * CA 93117, USA or visit http://www.eucalyptus.com/licenses/ if you need
 * additional information or have any questions.
 ************************************************************************/
package com.eucalyptus.loadbalancing.workflow;

import java.io.ByteArrayOutputStream;
import java.util.ArrayList;
import java.util.Map;

import com.eucalyptus.loadbalancing.common.msgs.LoadBalancerServoDescription;
import com.eucalyptus.loadbalancing.common.msgs.PolicyDescription;
import com.eucalyptus.loadbalancing.common.msgs.PolicyDescriptions;
import org.apache.log4j.Logger;

import com.eucalyptus.binding.Binding;
import com.eucalyptus.binding.BindingException;
import com.eucalyptus.binding.BindingManager;
import com.eucalyptus.cloudwatch.common.msgs.MetricData;
import com.eucalyptus.cloudwatch.common.msgs.MetricDatum;
import com.eucalyptus.loadbalancing.common.msgs.LoadBalancerServoDescriptions;
import com.eucalyptus.util.Exceptions;
import com.fasterxml.jackson.core.type.TypeReference;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.google.common.collect.Lists;

/**
 * @author Sang-Min Park (sangmin.park@hpe.com)
 *
 */
public class VmWorkflowMarshaller {
  private static final String LOADBALANCING_BINDING_NAME =
      "elasticloadbalancing_amazonaws_com_doc_2012_06_01";
  private static Logger    LOG     =
      Logger.getLogger(  VmWorkflowMarshaller.class );

  public static String marshalPolicy(final PolicyDescription policy) {
    final LoadBalancerServoDescriptions descriptions = new LoadBalancerServoDescriptions();
    final LoadBalancerServoDescription desc = new LoadBalancerServoDescription();

    final PolicyDescriptions policies = new PolicyDescriptions();
    policies.setMember(new ArrayList<PolicyDescription>());
    policies.getMember().add(policy);
    desc.setPolicyDescriptions(policies);

    descriptions.setMember(new ArrayList<LoadBalancerServoDescription>());
    descriptions.getMember().add(desc);
    return marshalLoadBalancer(descriptions);
  }

  public static String marshalLoadBalancer(final LoadBalancerServoDescriptions desc) {
    final Binding binding =
        BindingManager.getBinding(LOADBALANCING_BINDING_NAME);
    final ByteArrayOutputStream stream = new ByteArrayOutputStream();
    try{
      binding.toStream(stream, desc);
    }catch(final BindingException ex) {
      LOG.error("Marshalling failed", ex);
      throw Exceptions.toUndeclared(ex);
    }
    final String outString = new String(stream.toByteArray());
    return outString;
  }

  public static Map<String,String> unmarshalInstances(final String encodedStatus) {
    return decodeJsonStringMap(encodedStatus);
  }

  // only fill metric name and value;
  // dimension and unit is filled by caller
  public static MetricData unmarshalMetrics(final String metrics) {
    final Map<String,String> metricMap = decodeJsonStringMap(metrics);
    final MetricData data = new MetricData();

    data.setMember(Lists.<MetricDatum>newArrayList());
    for(final String name: metricMap.keySet()) {
      final MetricDatum datum = new MetricDatum();
      datum.setMetricName(name);
      try{
        datum.setValue(Double.valueOf(metricMap.get(name)));
      }catch(final NumberFormatException ex) {
        LOG.warn("Failed to parse metric value: " + metricMap.get(name));
      }
      data.getMember().add(datum);
    }
    return data;
  }

  public static Map<String,String> decodeJsonStringMap(final String encodedMap) {
    final ObjectMapper mapper = new ObjectMapper();
    final TypeReference<Map<String,String>> typeRef = new TypeReference<Map<String,String>>() {};
    try{
      final Map<String,String> decodedResult = mapper.readValue(encodedMap, typeRef);
      return decodedResult;
    }catch(final Exception ex) {
      throw Exceptions.toUndeclared("Failed to decode String map in json", ex);
    }
  }

}