package org.rpi.radio;
   
   import java.io.File;
   import java.io.StringReader;
   import java.io.StringWriter;
   import java.util.ArrayList;
   import java.util.List;
   
   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.apache.log4j.Logger;
  import org.w3c.dom.Document;
  import org.w3c.dom.Element;
  import org.w3c.dom.NamedNodeMap;
  import org.w3c.dom.Node;
  import org.w3c.dom.NodeList;
  import org.xml.sax.InputSource;
  
  public class ChannelReader {
  
      private static Logger log = Logger.getLogger(ChannelReader.class);
  
      private List<CustomChannel> channels = new ArrayList<CustomChannel>();
  
      private String metaData = "<DIDL-Lite xmlns='urn:schemas-upnp-org:metadata-1-0/DIDL-Lite/'><item id=''><dc:title xmlns:dc='http://purl.org/dc/elements/1.1/'></dc:title><upnp:artist role='Performer' xmlns:upnp='urn:schemas-upnp-org:metadata-1-0/upnp/'></upnp:artist><upnp:class xmlns:upnp='urn:schemas-upnp-org:metadata-1-0/upnp/'>object.item.audioItem</upnp:class><res bitrate='' nrAudioChannels='' protocolInfo='http-get:*:audio/mpeg:DLNA.ORG_PN=MP3;DLNA.ORG_OP=01'></res><upnp:albumArtURI xmlns:upnp='urn:schemas-upnp-org:metadata-1-0/upnp/'></upnp:albumArtURI></item></DIDL-Lite>";
  
      /***
       * Read the RadioList.xml file and build a List of Radio Channels
       * @return
       */
      public List<CustomChannel> getChannels() {
  
          try {
              channels.clear();
              DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
              DocumentBuilder builder = factory.newDocumentBuilder();
              Document doc = builder.parse(new File("RadioList.xml"));
              NodeList listOfChannels = doc.getElementsByTagName("Channel");
              int i = 1;
              for (int s = 0; s < listOfChannels.getLength(); s++) {
                  String id = null;
                  String url = null;
                  String image = "";
                  String s_icy_reverse ="";
                  boolean icy_reverse = false;
  
                  Node channel = listOfChannels.item(s);
                  if (channel.getNodeType() == Node.ELEMENT_NODE) {
                      Element element = (Element) channel;
                      id = getElement(element, "id");
                      url = getElement(element, "url");
                      image = getElement(element, "image");
                      s_icy_reverse = getElement(element,"icy_reverse");
                      if(s_icy_reverse.equalsIgnoreCase("TRUE"))
                      {
                          icy_reverse = true;
                      }
  
                  }
  
                  if (id != null && url != null) {
                      addChannel(id, url, image, i,icy_reverse);
                      i++;
                  }
              }
          } catch (Exception e) {
              log.error("Error Getting Radio List", e);
          }
          return channels;
      }
  
      /***
       *
       * @param element
       * @param name
       * @return
       */
      private String getElement(Element element, String name) {
          String res = "";
          NodeList nid = element.getElementsByTagName(name);
          if (nid != null) {
              Element fid = (Element) nid.item(0);
              if (fid != null) {
                  res = fid.getTextContent();
                  //log.debug("ElementName: " + name + " Value: " + res);
                  return res;
  
              }
          }
          return res;
      }
  
      /***
       * Create a Channel and add it to the List
      * @param name
      * @param url
      * @param image
      * @param id
      */
     private void addChannel(String name, String url, String image, int id,boolean icy_reverse) {
         String m = createMetaData(name, url, image);
         CustomChannel channel = new CustomChannel(url, m, id,name);
         channel.setICYReverse(icy_reverse);
         channels.add(channel);
         log.debug("Added Channel: " + channel.getUri() + " " + channel.getFullDetails());
     }
 
     /***
      * Build a simple MetaData String for the Channel
      * @param name
      * @param url
      * @param image
      * @return
      */
     private String createMetaData(String name, String url, String image) {
         String res = "";
 
         try {
 
             DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
             DocumentBuilder builder = factory.newDocumentBuilder();
             InputSource insrc = new InputSource(new StringReader(metaData));
             Document doc = builder.parse(insrc);
             Node node = doc.getFirstChild();
             Node item = node.getFirstChild();
             //int count = item.getAttributes().getLength();
             NamedNodeMap attts = item.getAttributes();
             Node nid = attts.getNamedItem("id");
             nid.setTextContent(name);
             log.debug("Item Child Nodes " + item.getChildNodes().getLength());
             NodeList childs = item.getChildNodes();
             for (int i = 0; i < childs.getLength(); i++) {
                 Node n = childs.item(i);
                 //log.debug("Name: " + n.getNodeName() + " Value " + n.getTextContent());
                 if (n.getNodeName() == "dc:title") {
                     n.setTextContent(name);
                 } else if (n.getNodeName() == "res") {
                     n.setTextContent(url);
                 } else if (n.getNodeName() == "upnp:albumArtURI") {
                     n.setTextContent(image);
                 } else if (n.getNodeName()=="upnp:artist")
                 {
                     n.setTextContent(name);
                 }
             }
             Transformer transformer = TransformerFactory.newInstance().newTransformer();
             StreamResult result = new StreamResult(new StringWriter());
             DOMSource source = new DOMSource(doc);
             transformer.transform(source, result);
             res = (result.getWriter().toString());
         } catch (Exception e) {
             log.error("Error Creating XML Doc", e);
         }
         return res;
     }
 
 }