package com.sample.app.usermanagement.web;

import java.io.IOException;
import java.sql.SQLException;
import java.util.List;

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

import com.sample.app.usermanagement.dao.UserDAO;
import com.sample.app.usermanagement.model.User;

/**
 * The page controller for the application, handling user requests.
 * 
 * @author Bill Chan AWS
 * 
 * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
 * SPDX-License-Identifier: MIT-0
 * 
 */

@WebServlet("/")
public class UserServlet extends HttpServlet {
	private static final long serialVersionUID = 1L;
	private UserDAO userDAO;
	
	public void init() {
		userDAO = new UserDAO();
	}

	protected void doPost(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {
		doGet(request, response);
	}

	protected void doGet(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {
		String action = request.getServletPath();

		try {
			switch (action) {
			case "/new":
				showNewForm(request, response);
				break;
			case "/insert":
				insertUser(request, response);
				break;
			case "/delete":
				deleteUser(request, response);
				break;
			case "/edit":
				showEditForm(request, response);
				break;
			case "/update":
				updateUser(request, response);
				break;
			default:
				listUser(request, response);
				break;
			}
		} catch (SQLException ex) {
			throw new ServletException(ex);
		}
	}

	private void listUser(HttpServletRequest request, HttpServletResponse response)
			throws SQLException, IOException, ServletException {
		List<User> listUser = userDAO.selectAllUsers();
		request.setAttribute("listUser", listUser);
		RequestDispatcher dispatcher = request.getRequestDispatcher("user-list.jsp");
		dispatcher.forward(request, response);
	}

	private void showNewForm(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {
		RequestDispatcher dispatcher = request.getRequestDispatcher("new-form.jsp");
		dispatcher.forward(request, response);
	}

	private void showEditForm(HttpServletRequest request, HttpServletResponse response)
			throws SQLException, ServletException, IOException {
		int id = Integer.parseInt(request.getParameter("id"));
		User existingUser = userDAO.selectUser(id);
		RequestDispatcher dispatcher = request.getRequestDispatcher("user-form.jsp");
		request.setAttribute("user", existingUser);
		dispatcher.forward(request, response);

	}

	private void insertUser(HttpServletRequest request, HttpServletResponse response) 
			throws SQLException, IOException {
		String name = request.getParameter("name");
		String email = request.getParameter("email");
		String company = request.getParameter("company");
		User newUser = new User(name, email, company);
		userDAO.insertUser(newUser);
		response.sendRedirect("list");
	}

	private void updateUser(HttpServletRequest request, HttpServletResponse response) 
			throws SQLException, IOException {
		int id = Integer.parseInt(request.getParameter("id"));
		String name = request.getParameter("name");
		String email = request.getParameter("email");
		String company = request.getParameter("company");

		User existingUser = new User(id, name, email, company);
		userDAO.updateUser(existingUser);
		response.sendRedirect("list");
	}

	private void deleteUser(HttpServletRequest request, HttpServletResponse response) 
			throws SQLException, IOException {
		int id = Integer.parseInt(request.getParameter("id"));
		userDAO.deleteUser(id);
		response.sendRedirect("list");

	}

}