package foundation.server;

import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.PrintStream;

import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;

import foundation.handler.DataPool;
import foundation.handler.DataPoolType;
import foundation.log.LogConfig;
import foundation.route.ClientAcceptType;
import foundation.route.ControllerNavigator;
import foundation.route.Route;
import foundation.route.RouteNavigator;
import foundation.route.RouteTable;
import foundation.route.RouteType;
import foundation.route.ServerErrorNavigator;
import foundation.server.config.Configer;
import foundation.token.IOnlineUser;
import foundation.token.IUserManager;
import foundation.translator.Translator;

public class Dispatcher implements Filter { 

	public static boolean AuthorizeActive;
	private static Dispatcher instance;
	private static Logger logger;

	static {
		logger = LogManager.getLogger(Dispatcher.class);
	}

	public Dispatcher() {
		instance = this;
	}

	public synchronized static Dispatcher getInstance() {
		if (instance == null) {
			instance = new Dispatcher();
		}

		return instance;
	}

	public void init(FilterConfig filterConfig) throws ServletException {
		AuthorizeActive = Translator.toBoolean(Configer.getString("AuthorizeActive"), true);
	}

	public void doFilter(ServletRequest req, ServletResponse res, FilterChain chain) throws IOException, ServletException {
		HttpServletRequest request = (HttpServletRequest) req;
		HttpServletResponse response = (HttpServletResponse) res;
		
		try {
			DataPool dataPool = null;
			request.setCharacterEncoding("utf-8");
			
			//1. route and get navigator
			RouteNavigator navigator = RouteTable.matchRoute(request);
			
			//2. log
			if (LogConfig.IsActive_Dispatcher_Trace) {
				logger.debug("filter request URI:" + navigator); 
			}
			
			//3. authorize
			if (navigator.isAuthorizeSensitive() && AuthorizeActive) {
				Route route = navigator.getRoute();
				
				//3.1 user token
				dataPool = new DataPool(request);
				
				if (DataPoolType.Options == dataPool.getType()) {
					ControllerNavigator.replyOptions(request, response);
					return;
				}
				
				String token = dataPool.getToken();
				IOnlineUser onlineUser = IUserManager.registerUser(token);
				dataPool.setUser(onlineUser);
				
				//3.2 go to login
				if (onlineUser.isAnymous()) {
					if (route == null) {
						logger.info("redirct to time out for request: {}", navigator);
						navigator.redirectToTimeOut(response, ClientAcceptType.Html);
						return;
					}
					
					RouteType routeType = route.getRouteType();
					
					if (RouteType.Controller == routeType) {
						logger.info("redirct to time out for request: {}", navigator);
						navigator.redirectToTimeOut(response, ClientAcceptType.Ajax);
						return;
					}
					
					navigator.redirectToTimeOut(response, ClientAcceptType.Html);
					return;
				} 
			}
			
			//4. send to
			navigator.sendTo(response, dataPool);
		}
		catch (Exception e) {
			String error = printStackToString(e);
			logger.error("dispatch error:" + e.getMessage());
			logger.error(error);
			
			RouteNavigator navigator = new ServerErrorNavigator(request);
			navigator.sendTo(response, null, e);
		}
	}
	
	public void destroy() {

	}

	private String printStackToString(Exception e) {
		ByteArrayOutputStream outStream = new ByteArrayOutputStream();
		PrintStream printStream = new PrintStream(outStream);
		e.printStackTrace(printStream);

		return outStream.toString();
	}

}