package DigiLibPdf;

import javax.servlet.*;
import javax.servlet.http.*;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.PrintWriter;
import java.net.MalformedURLException;
import java.net.URL;

import com.lowagie.text.*;
import com.lowagie.text.pdf.*;


public class DigiLibPdfCreator extends HttpServlet {
	
	/**
	 * 
	 */
	private static final long serialVersionUID = 1L;

	public DigiLibPdfCreator(){
		super();
		System.out.println("Initialized " + this.getClass().getName());

	}
	
	public void doGet(HttpServletRequest request, HttpServletResponse response) 
			throws javax.servlet.ServletException, java.io.IOException {
		
		ByteArrayOutputStream pdfOutStream = null;
		
		try {
			// get the PDF-data
			pdfOutStream = PdfDocumentFromUrl(request, this.getServletContext());
			
			// generate filename
			String filename = "image_download.pdf";
			
			// set HTTP headers
			response.setHeader("Cache-Control","max-age=30");
			response.setContentType("application/pdf");
			response.setHeader("Content-disposition", "inline; filename="+filename);
			response.setContentLength(pdfOutStream.size());
			
			
			// write pdf to output stream
			ServletOutputStream out = response.getOutputStream();
			
			pdfOutStream.writeTo(out);
			
			out.flush();
			
		}
		catch (DocumentException de){
			// inform the user about what went wrong
			response.setContentType("text/html");
			PrintWriter writer = response.getWriter();
			writer.println(this.getClass().getName() + " caught an exception: "  
						   + de.getClass().getName() + "<br/> <pre>");
			de.printStackTrace(writer);
			writer.println("</pre>");
		}
		
		finally {
			if (pdfOutStream != null){
				pdfOutStream.reset();
			}
		}
	}
	
	protected ByteArrayOutputStream PdfDocumentFromUrl(HttpServletRequest request, ServletContext servletcontext)
			 throws DocumentException {
		Document doc = new Document();
		ByteArrayOutputStream outstream = new ByteArrayOutputStream();
		
		PdfWriter docwriter = null;
		
		try{
			docwriter = PdfWriter.getInstance(doc, outstream);
			
			doc.addAuthor(this.getClass().getName());
			doc.addCreationDate();
			doc.addKeywords("digilib");
			doc.addTitle("digilib Image Printer");
			doc.addCreator(this.getClass().getName());
			
			// get width and height from the request
			int docW = 1, docH=1;
			
			doc.setPageSize(new Rectangle(0,0,docW,docH));
			
			// download the image from the URL
			Image img = Image.getInstance(new URL(request.getParameter("url")));

			img.scaleToFit(docW,docH);
			
			doc.add( img ); // 
			doc.open();
			// add all the images
			
		}
		catch (DocumentException de) {
			
		} catch (MalformedURLException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} finally{
			if (doc!=null){
				doc.close();
			}
			if (docwriter!=null){
				docwriter.close();
			}
		}
		return outstream;
	}
	
	
}