package ddth.dasp.servlet;

import java.io.IOException;
import java.util.HashMap;
import java.util.Map;
import java.util.Map.Entry;

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

import org.apache.catalina.comet.CometEvent;
import org.apache.catalina.comet.CometProcessor;

import ddth.dasp.common.DaspGlobal;
import ddth.dasp.common.IRequestHandler;
import ddth.dasp.common.api.IApiHandler;
import ddth.dasp.common.osgi.IOsgiBootstrap;
import ddth.dasp.common.utils.ServletUtils;

public class DaspDispatcherServletTomcatCommet extends HttpServlet implements CometProcessor {
    private static final long serialVersionUID = 1L;
    private final static Class<IRequestHandler> HANDLER_CLASS = IRequestHandler.class;

    private String contextPath;
    private Map<String, String> ERROR_PAGE_MAPPING = new HashMap<String, String>();
    private final static String ERROR_PAGE_403 = "/403.jsp";
    private final static String ERROR_PAGE_404 = "/404.jsp";
    private final static String ERROR_PAGE_500 = "/500.jsp";

    /**
     * {@inheritDoc}
     */
    @Override
    public void init() throws ServletException {
        super.init();
        contextPath = getServletContext().getContextPath();
        ERROR_PAGE_MAPPING.put(contextPath + ERROR_PAGE_403, ERROR_PAGE_403);
        ERROR_PAGE_MAPPING.put(contextPath + ERROR_PAGE_404, ERROR_PAGE_404);
        ERROR_PAGE_MAPPING.put(contextPath + ERROR_PAGE_500, ERROR_PAGE_500);
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public void event(CometEvent event) throws IOException, ServletException {
        HttpServletRequest request = event.getHttpServletRequest();
        HttpServletResponse response = event.getHttpServletResponse();
        switch (event.getEventType()) {
        case ERROR:
        case END: {
            event.close();
        }
        case BEGIN: {
            event.setTimeout(5000);// 5 seconds
            doHandleRequest(request, response);
            event.close();
        }
        default: {
            break;
        }
        }
    }

    /**
     * {@inheritDoc}
     */
    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response)
            throws IOException, ServletException {
        doHandleRequest(request, response);
    }

    /**
     * {@inheritDoc}
     */
    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response)
            throws IOException, ServletException {
        doHandleRequest(request, response);
    }

    protected void doHandleRequest(HttpServletRequest request, HttpServletResponse response)
            throws IOException, ServletException {
        String uri = request.getRequestURI();
        for (Entry<String, String> entry : ERROR_PAGE_MAPPING.entrySet()) {
            if (uri.startsWith(entry.getKey())) {
                RequestDispatcher rd = getServletContext().getRequestDispatcher(entry.getValue());
                rd.forward(request, response);
                return;
            }
        }
        IOsgiBootstrap osgiBootstrap = DaspGlobal.getOsgiBootstrap();
        IRequestHandler requestHandler = osgiBootstrap.getService(HANDLER_CLASS);
        if (requestHandler == null) {
            ServletUtils.responseHttpError(response, IApiHandler.RESULT_CODE_NOT_IMPLEMETED,
                    "No handler found!");
            return;
        }
        requestHandler.handleRequest(request, response);
    }
}