/*
    * 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.hadoop.chukwa.inputtools.jplugin;
  
  import java.io.StringWriter;
  import java.util.ArrayList;
  import java.util.Date;
  import java.util.Map.Entry;
  
  import javax.xml.parsers.DocumentBuilder;
  import javax.xml.parsers.DocumentBuilderFactory;
  import javax.xml.transform.Transformer;
  import javax.xml.transform.TransformerFactory;
  import javax.xml.transform.dom.DOMSource;
  import javax.xml.transform.stream.StreamResult;
  
  import org.w3c.dom.Document;
  import org.w3c.dom.Element;
  
  public class ChukwaMetricsList<T extends ChukwaMetrics> {
    private ArrayList<T> metricsList = null;
    private long timestamp = new Date().getTime();
    private String recordType = "JPlugin";
  
    public ChukwaMetricsList() {
    }
    
    public ChukwaMetricsList(String recordType) {
      setRecordType(recordType);
    }
    
    public void setMetricsList(ArrayList<T> metricsList) {
      this.metricsList = metricsList;
    }
  
    public ArrayList<T> getMetricsList() {
      if(metricsList == null){
        metricsList = new ArrayList<T>();
      }
      return metricsList;
    }
  
    public void addMetrics(T metrics) {
      getMetricsList().add(metrics);
    }
  
    public long getTimestamp() {
      return timestamp;
    }
  
    public void setTimestamp(long timestamp) {
      this.timestamp = timestamp;
    }
    
    public String toXml() throws Exception {
      DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
      DocumentBuilder docBuilder = null;
      docBuilder = factory.newDocumentBuilder();
      Document doc = docBuilder.newDocument();
      Element root = doc.createElement(getRecordType());
      doc.appendChild(root);
      root.setAttribute("ts", getTimestamp()+"");
      for(ChukwaMetrics metrics : getMetricsList()) {
        Element elem = doc.createElement("Metrics");
        elem.setAttribute("key", metrics.getKey());
        for(Entry<String, String> attr : metrics.getAttributes().entrySet()) {
          elem.setAttribute(attr.getKey(), attr.getValue());
        }
        root.appendChild(elem);
      }
      
      Transformer transformer = TransformerFactory.newInstance().newTransformer();
      transformer.setOutputProperty("indent", "yes");
      StringWriter sw = new StringWriter();
      transformer.transform(new DOMSource(doc), new StreamResult(sw));
      
      return sw.toString();
    }
  
    public void setRecordType(String recordType) {
      this.recordType = recordType;
    }
  
   public String getRecordType() {
     return recordType;
   }
   
 }