/*
 * File    : AbstractServlet.java
 * Created : 23-jan-2003 12:03
 * By      : fbusquets
 *
 * JClic - Authoring and playing system for educational activities
 *
 * Copyright (C) 2000 - 2005 Francesc Busquets & Departament
 * d'Educacio de la Generalitat de Catalunya
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details (see the LICENSE file).
 */

package edu.xtec.servlet;

import java.util.ArrayList;
import java.util.Enumeration;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import javax.servlet.*;
import javax.servlet.http.*;

/**
 *
 * @author Francesc Busquets (fbusquets@xtec.cat)
 * @version 13.09.17
 */
public abstract class AbstractServlet extends HttpServlet {

    public AbstractServlet(){
        super();
        RequestProcessor.setDirectResources(true);
    }
    
    @Override
    public void init(ServletConfig config) throws ServletException  {
        super.init(config);
        Enumeration en=config.getInitParameterNames();
        if(en.hasMoreElements()){
            Map<String, Object> map=new HashMap<String, Object>();
            while(en.hasMoreElements()){
                String key=(String)en.nextElement();
                String value=(String)config.getInitParameter(key);
            }
            RequestProcessor.config(map);
        }
    }

    protected void processRequest(HttpServletRequest request, HttpServletResponse response)
    throws ServletException, java.io.IOException {
        RequestProcessor rp=null;
        try{
            rp=createRP();
            if(rp.wantsInputStream())
                rp.setInputStream(request.getInputStream());
            else {
                Map<String, Object> v=new HashMap<String, Object>();
                Map parameters=request.getParameterMap();
                for(Object k : parameters.keySet()){
                    v.put((String)k, parameters.get(k));
                }
                rp.setParams(v);
            }
            Cookie[] ck=request.getCookies();
            if(ck!=null)
                for(int i=0; i<ck.length; i++)
                    rp.setCookie(ck[i].getName(), ck[i].getValue());
            Enumeration en=request.getHeaderNames();
            Map<String, Object> map=new HashMap<String, Object>();
            while(en.hasMoreElements()){
                String name=(String)en.nextElement();
                Enumeration enh=request.getHeaders(name);
                List<String> v=new ArrayList<String>();
                while(enh.hasMoreElements())
                    v.add((String)enh.nextElement());
                map.put(name.toLowerCase(), v);
            }
            rp.setHeaders(map);
            rp.init();
            if(rp.noCache()){
                response.setHeader("Pragma", "no-cache");
                response.setHeader("Cache-Control", "no-cache");
                response.setHeader("Expires", "0");                
            }
            List<String[]> v=new ArrayList<String[]>();
            rp.header(v);
            if(!v.isEmpty()){
                Iterator it=v.iterator();
                while(it.hasNext() && !response.isCommitted()){
                    String[] h=(String[])it.next();
                    if(h[0].equals(RequestProcessor.ERROR)){
                        int code=Integer.parseInt(h[1]);
                        response.sendError(code, h[2]);
                    }
                    if(h[0].equals(RequestProcessor.REDIRECT)){
                        response.sendRedirect(h[1]);
                        break;
                    }
                    else if(h[0].equals(RequestProcessor.CONTENT_TYPE))
                        response.setContentType(h[1]);
                    else if(h[0].equals(RequestProcessor.CONTENT_LENGTH))
                        response.setContentLength(Integer.parseInt(h[1]));
                    else if(h[0].equals(RequestProcessor.EXTRA))
                        response.setHeader(h[1], h[2]);                    
                    else if(h[0].equals(RequestProcessor.COOKIE))
                        response.addCookie(new Cookie(h[1], h[2]));
                }
            }
            if(!response.isCommitted()){
                if(rp.usesWriter()){
                    java.io.PrintWriter pw=response.getWriter();
                    rp.process(pw);
                    try{
                        pw.flush();
                        pw.close();
                    } catch(Exception ex){
                        // ...
                    }
                } else{
                    java.io.OutputStream os=response.getOutputStream();
                    rp.process(os);
                    try{
                        os.flush();
                        os.close();
                    } catch(Exception ex){
                        // ...
                    }
                }
            }
            rp.end();
            rp=null;   
        }
        catch(Exception ex){
            int errCode = rp!=null && rp.errCode>=0 ? rp.errCode : HttpServletResponse.SC_INTERNAL_SERVER_ERROR;
            String errMsg = rp!=null && rp.errMsg!=null ? rp.errMsg : ex.getMessage();
            if(!response.isCommitted()){
                response.sendError(errCode, errMsg);
            }
            System.err.println("ERROR "+errCode+": "+errMsg);
            ex.printStackTrace(System.err);
        }
        finally {
            if(rp!=null)
                rp.end();
        }     
    }
    
    protected abstract RequestProcessor createRP() throws Exception;
    
    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response)
    throws ServletException, java.io.IOException {
        processRequest(request, response);
    }
    
    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response)
    throws ServletException, java.io.IOException {
        processRequest(request, response);
    }
}