package no.auc.one.portableplayer.communication.mediarenderer;

import java.io.*;
import java.util.*;
import javax.microedition.io.*;
import javax.xml.parsers.*;
import org.xml.sax.*;
import org.xml.sax.helpers.DefaultHandler;
import org.apache.log4j.*;

import no.auc.one.portableplayer.communication.*;
import no.auc.one.portableplayer.utils.*;

// XXX A lot of the functionality of this class is common with MediaServer. Should be 
//     possible to refactor these, and move some of the functionality up to the 
//     super class (UPnPDevice)

/**
 * Functionality for interacting with a UPnP Media Renderer. Currently it 
 * only supports the AV Transport service.
 * 
 * Usage example:
 * MediaRenderer mr = new MediaRenderer();
 * for(Enumerable e = mr.getMediaServers(); e.hasMoreElements(); ) {
 *    // Here you can interact with the specific media renderers discovered.
 * }
 */
public class MediaRenderer extends UPnPDevice implements Cloneable, CancelAction {
    private static Logger LOG = Logger.getLogger("MR");
    
    private static MediaRenderer[] mediaRenderers = null;
    private AVTransportService avTransport = null;
    private RenderingControlService rcontrol = null;
    private UPnPDiscovery discoRenderers = null;
    private boolean isUpdatingList = false;
	
    /**
     * Default constructor.
     */
	public MediaRenderer() {
        super();
	}

    /**
     * Creates a new MediaRenderer based on the parameters.
     *
     * @param dev UPnPDevice to use as the base for this class. Will be 
     *            copied, and no reference stored.
     *
     * @param avt Reference to a AVTransportService instance to be associated 
     *            with this class.
     * @param rcs Reference to a RenderingControlService instance to be associated
     *            with this class.
     */
    public MediaRenderer(UPnPDevice dev, AVTransportService avt, RenderingControlService rcs) {
        super(dev.getFriendlyName(), dev.getURLBase());
        
        this.avTransport = avt;
        this.rcontrol = rcs;
    }

    /**
     * Clone this class instance
     *
     * @return Copy of this device.
     */
    public Object clone() {
        MediaRenderer mr = new MediaRenderer(
            (UPnPDevice)this, 
            (AVTransportService)avTransport.clone(),
            (RenderingControlService)rcontrol.clone());
        return mr;
    }
    
    public void cancel() throws IOException {
        discoRenderers.cancel();
    }

    /**
     * Return the available media renderers found on the local network. Will 
     * update the list of available media renderers if it does not currently 
     * exist.
     *
     * @return Let you enumerate the discovered renderers.
     */
    // TODO Add auto-update for discovery (each hour or similar) see 
    //      MediaServer::getMediaServers for more info
    public Enumeration getMediaRenderers() throws NoSuchElementException,
                                                  IOException
    {
        if (mediaRenderers == null) {
            throw new IllegalStateException(
                "Media Renderers have not been discovered yet. Do updateMediaRendererList first.");
        }

        MediaRenderer[] rendererListClone = null;
        if (mediaRenderers != null) {
            rendererListClone = new MediaRenderer[mediaRenderers.length];
        
            for(int i = 0; i < mediaRenderers.length; i++) {
                rendererListClone[i] = (MediaRenderer)mediaRenderers[i].clone(); 
            }
        }

        return new MediaRendererEnumeration(rendererListClone);
    }
    
    public MediaRenderer getMediaRenderer(int index) throws NoSuchElementException, IOException {
        MediaRenderer mr = null;
        
        if (mediaRenderers == null) {
            throw new IllegalStateException(
                "Media Renderers have not been discovered yet. Do updateMediaRendererList first.");
        }

        if (mediaRenderers != null) {
            mr = (MediaRenderer)mediaRenderers[index].clone();
        }

        return mr;
    }
    
	public void updateMediaRendererList() throws IOException
	{		
        if (isUpdatingList) {
            return;
        } else {
            isUpdatingList = true;
        }

        try {
    		discoRenderers = new UPnPDiscovery(); 
    		String[] rendererLocationUrls = discoRenderers.start(
    			"urn:schemas-upnp-org:device:MediaRenderer:1",
    			5); // max duration set to 5 seconds
            
            if (rendererLocationUrls == null || rendererLocationUrls.length <= 0) {
                LOG.debug("No media renderers discovered.");
                mediaRenderers = null;
                return;
            } else {
                LOG.debug(
                    "Media Renderers discovered: " + rendererLocationUrls.length);
            }
    
            // Need to make the following more robust.
            // First add all available renderers to a vector. Then add all these devices 
            // to the mediaRenderers list
            
            Vector availableRenderers = new Vector();
            SAXParser parser = null;
            
            try {
                SAXParserFactory pfactory = SAXParserFactory.newInstance();
                parser = pfactory.newSAXParser();
            } catch (ParserConfigurationException pce) {
                LOG.fatal("PCE exception in updateMediaRendererList");
                LOG.fatal(pce);
            } catch (SAXException se) {
                LOG.fatal("SAXException in updateMediaRendererList");
                LOG.fatal(se);
            }
    
            if (parser == null) {
                mediaRenderers = null;
                return;
            }
            
    		for(int index = 0; index < rendererLocationUrls.length; index++)
    		{		
    			HttpConnection conn = null;
    			
                try{					
                    LOG.debug(
                        "MR" + index + ": " + rendererLocationUrls[index]);
    
    			    conn = (HttpConnection)Connector.open(
                        rendererLocationUrls[index]);
    				conn.setRequestMethod(HttpConnection.GET);
    				conn.setRequestProperty("Content-Length","0");				
                    MediaRenderer mr = new MediaRenderer();
                    MediaRendererDeviceDescriptionHandler mrddHandler = new 
                        MediaRendererDeviceDescriptionHandler(
                            mr, 
                            rendererLocationUrls[index]);
    
                    parser.parse(conn.openInputStream(), mrddHandler);
                    conn.close();
                    
                    LOG.debug(
                        "MediaRenderer found (" + index + ")" + 
                        " Name: " + mr.friendlyName + 
                        " URLBase: "  + mr.urlBase + 
                        " AVT: " + mr.avTransport.toString() + 
                        " RCS: " + mr.rcontrol.toString());
                    availableRenderers.addElement(mr);
                } catch (SAXException se) {
                    LOG.fatal("SAXExceptio in updateMediaRendererList");
                    LOG.fatal(se);
    			} catch (ConnectionNotFoundException cnfe) { 
                    LOG.fatal("Connection not found.");
                    LOG.fatal(cnfe);
    			} catch (IOException ioe) {
                    LOG.fatal(
                        "Error while getting device description for MR" + index);
                    LOG.fatal(ioe);
                }
    	    }		   
            
            if (availableRenderers == null || availableRenderers.size() <= 0) {
                mediaRenderers = null;
                return;
            }
            
            mediaRenderers = new MediaRenderer[availableRenderers.size()];
            for(int i = 0; i < availableRenderers.size(); i++) {
                mediaRenderers[i] = (MediaRenderer)availableRenderers.elementAt(i);
            }
        } finally {
            discoRenderers = null;
            isUpdatingList = false;
        }
	}
    
    /**
     * Get this device's associated AV Transport Service instance.
     *
     * @return AV Transport Service instance.
     */
    public AVTransportService getAVTransportService() {
        return avTransport;
    }
    
    /**
     * Get this device's associated Rendering Control Service instance.
     *
     * @return Rendering Control instance.
     */
    public RenderingControlService getRenderingControlService() {
        return rcontrol;
    }
    
    /**
     * Used to parse the device description of Media Renderers.
     */
    private class MediaRendererDeviceDescriptionHandler extends DefaultHandler{
    	private MediaRenderer mr;
    	private Vector services = new Vector();
        private Stack tagStack = new Stack();
        private String locationURL;
        
    	public MediaRendererDeviceDescriptionHandler(MediaRenderer mr, String url) {
            this.mr = mr;
            locationURL = url;
        }
        
        public void startElement(
            String uri, 
            String localName, 
            String qName, 
            Attributes attributes) throws SAXException 
        {
        	if(qName.equals("service")) {
                // Should know if the device description contains an URLBase 
                // element or not at this point
                if(mr.urlBase == null || mr.urlBase == "") {
                    // Use locationURL as URLBase
                    mr.urlBase = getHostAndPort(locationURL);
                }
                
                services.addElement(new UPnPService());
            }
            
        	tagStack.push(qName);
        }
        
        public void characters(char[] ch, int start, int length) throws SAXException {
            String chars = new String(ch, start, length).trim();
            
            if(chars.length() > 0) {
                String qName = (String)tagStack.peek();
                            
                if (qName.equals("friendlyName")) {
                    mr.friendlyName = chars;
                } else if (qName.equals("URLBase")) {
                	mr.urlBase = chars;
                } else if (qName.equals("serviceType")) {
                	UPnPService currentService = (UPnPService)services.lastElement();
                	currentService.setServiceType(chars);
                } else if (qName.equals("serviceId")) {
                	UPnPService currentService = (UPnPService)services.lastElement();
                	currentService.setServiceId(chars);
                } else if (qName.equals("controlURL")) {
                	UPnPService currentService = (UPnPService)services.lastElement();
                	currentService.setControlURL(mr.urlBase + chars);
                } else if (qName.equals("SCPDURL")) {
                	UPnPService currentService = (UPnPService)services.lastElement();
                	currentService.setSCPDURL(mr.urlBase + chars);
                } else if (qName.equals("eventSubURL")) {
                	UPnPService currentService = (UPnPService)services.lastElement();
                	currentService.setEventSubURL(mr.urlBase + chars);
                }
            }
        }
        
        public void endElement(String uri, String localName, String qName) throws SAXException {
        	tagStack.pop();    	
        }
        
        public void endDocument() throws SAXException {
    		if (services == null) {
    			return;
    		}
    
        	for (int i=0; i < services.size(); i++){
        		UPnPService currentService = (UPnPService)services.elementAt(i);
        		
        		if (currentService == null) {
                    LOG.debug("Null service detected. Possibly a bug somewhere?");
        			continue;
        		}
                
        		if (currentService.getServiceType().equals(
                        "urn:schemas-upnp-org:service:AVTransport:1")){
                    mr.avTransport = new AVTransportService(currentService);
                } else if (currentService.getServiceType().equals(
                        "urn:schemas-upnp-org:service:RenderingControl:1")){
                    mr.rcontrol = new RenderingControlService(currentService);
                } else {
                    LOG.debug("Unknown service found: " + currentService.getServiceType());
                }
        	}
        }

    	/**
    	 * Analyze the rendererLocationUrls to get only the address and port
    	 * @param url URL to find host and port of.
    	 * @return Returns host and port of an URL
    	 */
    	private String getHostAndPort(String url) {
    		int ss = 0;
    		for (int i = 8; i < url.length(); i++) {			
    		    ss=url.substring(8).indexOf('/');
    		}
            
    		return url.substring(0, ss + 9);
    	}
    }

    /**
     * Used for enumerating available Media Renderers.
     */
    private class MediaRendererEnumeration implements Enumeration {
        private MediaRenderer[] rendererList;
        private int currentIndex;
        
        public MediaRendererEnumeration (
            MediaRenderer[] renderers) 
        {
            rendererList = renderers;
            currentIndex = 0;
        }

        public boolean hasMoreElements() {
            if (rendererList == null || currentIndex > (rendererList.length - 1)) {
                return false;
            } else {
                return true;
            }
        }

        public Object nextElement() {
            if (hasMoreElements()) {
                return rendererList[currentIndex++];
            } else {
                throw new NoSuchElementException("No more Media Renderers available");
            }
        }
    }
}