package statistic;

import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import java.util.*;


public class VisitServlet extends HttpServlet {

	/**
	 * Constructor of the object.
	 */
	public VisitServlet() {
		super();
	}

	/**
	 * Destruction of the servlet. <br>
	 */
	public void destroy() {
		super.destroy(); // Just puts "destroy" string in log
		// Put your code here
	}

	public void doGet(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {

		HttpServletRequest httpRequest = (HttpServletRequest) request;
		
		String ip = httpRequest.getRemoteAddr();
		String agent = httpRequest.getHeader("User-Agent");
		StringTokenizer st = new StringTokenizer(agent, ";)");
		st.nextToken();
		String browser = st.nextToken();
		String os = st.nextToken();

		if (ip == null) {
			ip = "未知";
		}
		if (browser == null) {
			browser = "未知";
		}
		if (os == null) {
			os = "未知";
		}
		
		String pageName = httpRequest.getParameter("pageName");
		
		DatabaseService.visit(ip, os.trim(), browser.trim(), pageName);
		
		forward(request, response, "/"+pageName);
	}
	
    /**
     * 將控制流程轉到url所表示的頁面
	 */
    private void forward(HttpServletRequest request, HttpServletResponse response, String url) {
        try {
            request.getRequestDispatcher(response.encodeURL(url)).
                forward(request, response);
        }
        catch (Exception es) {
            es.printStackTrace();
        }
    }

	/**
	 * The doPost method of the servlet. <br>
	 *
	 * This method is called when a form has its tag value method equals to post.
	 * 
	 * @param request the request send by the client to the server
	 * @param response the response send by the server to the client
	 * @throws ServletException if an error occurred
	 * @throws IOException if an error occurred
	 */
	public void doPost(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {


	}

	/**
	 * Initialization of the servlet. <br>
	 *
	 * @throws ServletException if an error occure
	 */
	public void init() throws ServletException {
		// Put your code here
	}


}