package webraveler.plugin;

import java.util.*;
import java.io.*;

import webraveler.http.HTTPRequest;
import webraveler.http.HTTPResponse;
import webraveler.ravel.PluginAPI;
import webraveler.ravel.PluginCallbackException;
import webraveler.ravel.Raveler;
import webraveler.vurl.HelpVURL;

/**
 *
 */

public class NoImagesPlugin extends webraveler.ravel.RavelerPlugin {
	/* variables */
	private byte[] imageBytes;
	private HTTPResponse response;
	private boolean DEBUG = false;
	
	/*constructors*/
	public NoImagesPlugin () throws Exception{
		
		/* let's load the image at instantiation time */
		System.out.println("NoImagesPlugin: Getting dummy image byte array.");
		File image = new File(Raveler.WEBRAVELER_HOME+"/data/images/noimage.png");
		FileInputStream imageIn; 
		
		try {
			imageIn = new FileInputStream(image);
		}catch (IOException ioe) { 
			throw new Exception("NoImagesPlugin: couldn't get dummy image file.");
		}//catch
		
		ByteArrayOutputStream byteStream = new ByteArrayOutputStream();
		int input;
		while( (input = imageIn.read()) != -1 ) {
			byteStream.write(input); // write the input byte to the stream...
		}
		
		imageBytes = byteStream.toByteArray();
		
		name = "NoImagesPlugin";
		mimeTypes.add("image/gif");
		mimeTypes.add("image/jpeg");
		mimeTypes.add("image/png");
	}
	
	/*methods*/
	
	public void setDefaultAttributes () {
		attributes = new Hashtable();
		name = "NoImagesPlugin";
	} 
	
	public boolean initialize () {
		/* some helpful HTML to display to the user */
		String helpfulHTML = new String();
		helpfulHTML += "<html><head>"+Raveler.ravelerCSS+"<title>WebRaveler2 :: NoImagesPlugin Help Page</title></head>";
		helpfulHTML += "<body><p class='level1'>NoImagesPlugin :: Help</p>";
		helpfulHTML += "<p><h3><ul><li>Activating this plugin causes requests for common image files to ";
		helpfulHTML += "return a one-pixel image from the WebRaveler directory.</li>";
		helpfulHTML += "<li> Responses will also be checked for content-type headers indicating image files, and those will ";
		helpfulHTML += "be handled in the same manner as requests. </li> </ul>  Thank you for using NoImagesPlugin.</h3>";
		helpfulHTML += "</body></html>";
		
		HelpVURL help = new HelpVURL(helpfulHTML);
		String fullURL = PluginAPI.addHelpVirtualURL(ravel,name,help);
		return true;
	}//initialize()
	
	public HTTPRequest execute (HTTPRequest request, Hashtable attributes) throws PluginCallbackException {	
		if ( DEBUG ) System.out.println("NoImagesPlugin: executing on request for "+request.uriString());
		String uri = request.uriString().toLowerCase();
		if (   !uri.endsWith(".gif") &&
				!uri.endsWith(".jpg") &&
				!uri.endsWith(".jpeg") &&
				!uri.endsWith(".png") ) {
			return request;	
		}//if 
		
		if (DEBUG) System.out.println("NoImagesPlugin: request for image file.  Returning dummy image.");
		
		/* construct a new response to send back */
		HTTPResponse response = new HTTPResponse();
		response.protocolVersion = "HTTP/1.0";
		response.status = 200;
		response.entityBytes = imageBytes;
		
		response.setHeader("content-type","image/gif");
		
		/* put in the right content-length header */
		response.setHeader("content-length",""+imageBytes.length);
		
		throw new PluginCallbackException(response);
	}//execute()
	
	
	
	public HTTPResponse execute (HTTPResponse response, Hashtable attributes) throws PluginCallbackException {
		if (DEBUG) System.out.println("NoImagesPlugin: executing on response...");
		
		response.entityBytes = imageBytes;
		
		response.deleteHeader("content-length");
		response.setHeader("content-length", new String(""+response.entityBytes.length));
		
		response.deleteHeader("content-type");
		response.setHeader("content-type", "image/gif");
		
		response.protocolVersion = "HTTP/1.0";
		response.status = 200;
		response.reasonPhrase = "OK";
		
		response.htmlPage = null;
		
		response.deleteHeader("connection");
		response.setHeader("connection", new String("close"));
		
		throw new PluginCallbackException(response);
	} //execute(HTTPResponse)
	
	
	public  void terminate() {
		
	} // terminate()
	
}//InsertAtTop