package de.intevation.flys.client.server;

import java.io.InputStream;
import java.io.ByteArrayOutputStream;

import org.apache.log4j.Logger;
import org.apache.commons.codec.binary.Base64;
import org.apache.commons.fileupload.FileItemIterator; 
import org.apache.commons.fileupload.FileItemStream; 
import org.apache.commons.fileupload.servlet.ServletFileUpload; 
import org.apache.commons.fileupload.FileUploadException;

import org.w3c.dom.Document;
import org.w3c.dom.Element;

import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import com.google.gwt.user.server.rpc.RemoteServiceServlet;

import de.intevation.artifacts.common.utils.XMLUtils;
import de.intevation.artifacts.common.utils.XMLUtils.ElementCreator;

import de.intevation.artifacts.httpclient.exceptions.ConnectionException;
import de.intevation.artifacts.httpclient.http.HttpClient;
import de.intevation.artifacts.httpclient.http.HttpClientImpl;

import de.intevation.flys.client.shared.exceptions.ServerException;

public class FileUploadServiceImpl
extends      HttpServlet
{
    private static final Logger logger = Logger.getLogger(FileUploadServiceImpl.class);

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) {
        processPost(req, resp);
    }


    protected void processPost(HttpServletRequest req, HttpServletResponse resp) {
        logger.debug("handling post request.");

        String url  = getServletContext().getInitParameter("server-url");

        Document request = createFileXML(req);;

        if (request == null) {
            return;
        }
        HttpClient client = new HttpClientImpl(url);

        try {
            Document result = client.callService(url, "fileupload", request);

            if (result == null) {
                logger.warn("FileUpload service returned no result.");
            }

            return;
        }
        catch (ConnectionException ce) {
            logger.error(ce, ce);
        }
    }


    protected Document createFileXML(HttpServletRequest req) {
           ServletFileUpload upload = new ServletFileUpload();

        try{
            FileItemIterator iter = upload.getItemIterator(req);

            while (iter.hasNext()) {
                FileItemStream item = iter.next();

                String name = item.getFieldName();
                InputStream stream = item.openStream();


                // Process the input stream
                ByteArrayOutputStream out = new ByteArrayOutputStream();
                int len;
                byte[] buffer = new byte[stream.available()];
                while ((len = stream.read(buffer, 0, buffer.length)) != -1) {
                    out.write(buffer, 0, len);
                }

                Base64 encoder = new Base64();
                String b64File = Base64.encodeBase64String(buffer);

                Document fileDoc = XMLUtils.newDocument();

                ElementCreator ec = new ElementCreator(fileDoc, null, null);
                Element root = ec.create("upload");
                Element id = ec.create("artifact-uuid");
                id.setTextContent(req.getParameter("uuid"));

                Element data = ec.create("data");
                data.setTextContent(b64File);

                fileDoc.appendChild(root);
                root.appendChild(id);
                root.appendChild(data);

                return fileDoc;
            }
        }
        catch(Exception e){
            logger.debug("Failed to create xml document containing the file.");
            logger.debug(e, e);
        }
        return null;
    }
}