/*
 * SSOFilter.java
 *
 * Created on 2006年5月5日, 下午4:56
 */

package SSO;

import java.io.*;
import java.net.*;
import java.util.*;
import java.text.*;
import javax.servlet.*;
import javax.servlet.http.*;

import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;

import org.apache.commons.httpclient.*;
import org.apache.commons.httpclient.methods.GetMethod;

/**
 *
 * @author  yw137672
 * @version
 */

public class SSOFilter implements Filter {
    
    private FilterConfig filterConfig = null;
    private String cookieName = "WangYuDesktopSSOID";
    private String SSOServiceURL = "http://wangyu.prc.sun.com:8080/SSOAuth/SSOAuth";
    private String SSOLoginPage = "http://wangyu.prc.sun.com:8080/SSOAuth/login.jsp";
    
    public SSOFilter() {
    }
    
  
    
    /**
     *
     * @param request The servlet request we are processing
     * @param result The servlet response we are creating
     * @param chain The filter chain we are processing
     *
     * @exception IOException if an input/output error occurs
     * @exception ServletException if a servlet error occurs
     */
    public void doFilter(ServletRequest req, ServletResponse res, FilterChain chain)
            throws IOException, ServletException {
        
        if (debug) log("SSOFilter:doFilter()");
        
        HttpServletRequest request = (HttpServletRequest) req;
        HttpServletResponse response = (HttpServletResponse) res;
        String result="failed";
        String url = request.getRequestURL().toString();
        String qstring = request.getQueryString();
        if (qstring == null) qstring ="";
        String cookieValue ="";
        javax.servlet.http.Cookie[] diskCookies = request.getCookies();
        if (diskCookies != null) {
            
            for (int i = 0; i < diskCookies.length; i++) {
                if(diskCookies[i].getName().equals(cookieName)){
                    cookieValue = diskCookies[i].getValue();
                    result = SSOService(cookieValue);
                    if (debug) log("found cookies!");
                }
            }
            
        }
        if (result.equals("failed")) {
            response.sendRedirect(SSOLoginPage+"?goto="+url);
        } else if (qstring.indexOf("logout") > 1) {
            if (debug) log("logout action!");
            logoutService(cookieValue);
            response.sendRedirect(SSOLoginPage+"?goto="+url);
        }  else {
            request.setAttribute("SSOUser",result);
            Throwable problem = null;
            try {
                chain.doFilter(req, res);
            } catch(Throwable t) {
                problem = t;
                t.printStackTrace();
            }       
            if (problem != null) {
                if (problem instanceof ServletException) throw (ServletException)problem;
                if (problem instanceof IOException) throw (IOException)problem;
                sendProcessingError(problem, res);
            }
            
        }   
    }
    
    
    /**
     * Return the filter configuration object for this filter.
     */
    public FilterConfig getFilterConfig() {
        return (this.filterConfig);
    }
    
    
    /**
     * Set the filter configuration object for this filter.
     *
     * @param filterConfig The filter configuration object
     */
    public void setFilterConfig(FilterConfig filterConfig) {
        
        this.filterConfig = filterConfig;
    }
    
    /**
     * Destroy method for this filter
     *
     */
    public void destroy() {
    }
    
    
    /**
     * Init method for this filter
     *
     */
    public void init(FilterConfig filterConfig) {
        
        this.filterConfig = filterConfig;
        if (filterConfig != null) {
            if (debug) {
                log("SSOFilter:Initializing filter");
            }
        }
        
        cookieName = filterConfig.getInitParameter("cookieName");
        SSOServiceURL = filterConfig.getInitParameter("SSOServiceURL");
        SSOLoginPage = filterConfig.getInitParameter("SSOLoginPage");
    }
    
    /**
     * Return a String representation of this object.
     */
    public String toString() {
        
        if (filterConfig == null) return ("SSOFilter()");
        StringBuffer sb = new StringBuffer("SSOFilter(");
        sb.append(filterConfig);
        sb.append(")");
        return (sb.toString());
        
    }
    
    
    
    private void sendProcessingError(Throwable t, ServletResponse response) {
        
        String stackTrace = getStackTrace(t);
        
        if(stackTrace != null && !stackTrace.equals("")) {
            
            try {
                
                response.setContentType("text/html");
                PrintStream ps = new PrintStream(response.getOutputStream());
                PrintWriter pw = new PrintWriter(ps);
                pw.print("<html>\n<head>\n<title>Error</title>\n</head>\n<body>\n"); //NOI18N
                
                // PENDING! Localize this for next official release
                pw.print("<h1>The resource did not process correctly</h1>\n<pre>\n");
                pw.print(stackTrace);
                pw.print("</pre></body>\n</html>"); //NOI18N
                pw.close();
                ps.close();
                response.getOutputStream().close();;
            }
            
            catch(Exception ex){ }
        } else {
            try {
                PrintStream ps = new PrintStream(response.getOutputStream());
                t.printStackTrace(ps);
                ps.close();
                response.getOutputStream().close();;
            } catch(Exception ex){ }
        }
    }
    
    public static String getStackTrace(Throwable t) {
        
        String stackTrace = null;
        
        try {
            StringWriter sw = new StringWriter();
            PrintWriter pw = new PrintWriter(sw);
            t.printStackTrace(pw);
            pw.close();
            sw.close();
            stackTrace = sw.getBuffer().toString();
        } catch(Exception ex) {}
        return stackTrace;
    }
    
    
    private String SSOService(String cookievalue) throws IOException {
        String authAction = "?action=authcookie&cookiename=";
        HttpClient httpclient = new HttpClient();
        GetMethod httpget = new GetMethod(SSOServiceURL+authAction+cookievalue);
        try {
            
            httpclient.executeMethod(httpget);
            String result = httpget.getResponseBodyAsString();
            return result;
        } finally {
            httpget.releaseConnection();
        }
    }
    
    private void logoutService(String cookievalue) throws IOException {
        String authAction = "?action=logout&cookiename=";
        HttpClient httpclient = new HttpClient();
        GetMethod httpget = new GetMethod(SSOServiceURL+authAction+cookievalue);
        try {
            httpclient.executeMethod(httpget);
            httpget.getResponseBodyAsString();
        } finally {
            httpget.releaseConnection();
        }
    }
    
    
    public void log(String msg) {
        filterConfig.getServletContext().log(msg);
    }
    
    private static final boolean debug = true;
}