package dk.thoerup.curcuitbreaker.web;

import java.io.IOException;

import javax.servlet.ServletException;
import javax.servlet.http.*;

/**
 * This is a web interface for viewing and controlling the CircuitBreakers currently registered in CircuitBreakerManager
 * <p> 
 * To use this servlet in you .war module just create a simple servlet that extends this class (instead of HttpServlet)
 * The new custom servlet doesn't need to implement any of the standard servlet methods - its all done in this implementation.
 *  
 * <p>
 * Example:
 * <pre>
 * public class CircuitBreakerServlet extends CircuitBreakerServletBase {
 *   private static final long serialVersionUID = 1L;
 * }
 * </pre>
 */

public class CircuitBreakerServletBase  extends javax.servlet.http.HttpServlet  {
	
	private static final long serialVersionUID = 1L;
	
	private Command getCommand(String command) throws ServletException {
		if (command == null || command.equals("list"))
			return new ListCircuitBreakers();
		
		if (command.equals("view"))
			return new ViewCircuitBreaker();
		
		throw new ServletException("No such action:" + command);
	}

	public void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
		Command cmd = getCommand( req.getParameter("command"));
		
		String response = cmd.execute(req,resp);
		
		resp.setDateHeader("Expires", 0);
		resp.setHeader("Pragma", "no-cache");
		resp.setHeader("Cache-Control", "no-cache");
		
		resp.getWriter().print(response);
	}

	@Override
	protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
		doGet(req, resp);
	}
	
	
	
	

}