import java.io.IOException;
import java.io.InputStream;
import java.io.PrintStream;
import java.net.InetSocketAddress;
import java.net.Socket;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Scanner;

import org.apache.commons.net.telnet.TelnetClient;




public class Main {

    static private class AutomatedTelnetClient {
        private TelnetClient telnet = new TelnetClient();
        private InputStream in;
        private PrintStream out;
        private String prompt = "#";

        public AutomatedTelnetClient(String server, String user, String password) {
            try {
// Connect to the specified server
                telnet.connect(server, 23);

// Get input and output stream references
                in = telnet.getInputStream();
                out = new PrintStream(telnet.getOutputStream());

// Log the user on
                readUntil("login:");
                write(user);
                readUntil("Password: ");
                write(password);

// Advance to a prompt
                readUntil(prompt + " ");
            } catch (Exception e) {
                e.printStackTrace();
            }
        }

        public void su(String password) {
            try {
                write("su");
                readUntil("Password: ");
                write(password);
                prompt = "#";
                readUntil(prompt + " ");
            } catch (Exception e) {
                e.printStackTrace();
            }
        }

        public String readUntil(String pattern) {
            try {
                char lastChar = pattern.charAt(pattern.length() - 1);
                StringBuffer sb = new StringBuffer();
                boolean found = false;
                char ch = (char) in.read();
                while (true) {
                    System.out.print(ch);
                    sb.append(ch);
                    if (ch == lastChar) {
                        if (sb.toString().endsWith(pattern)) {
                            return sb.toString();
                        }
                    }
                    ch = (char) in.read();
                }
            } catch (Exception e) {
                e.printStackTrace();
            }
            return null;
        }

        public void write(String value) {
            try {
                out.println(value);
                out.flush();
                System.out.println(value);
            } catch (Exception e) {
                e.printStackTrace();
            }
        }

        public String sendCommand(String command) {
            try {
                write(command);
                return readUntil(prompt + " ");
            } catch (Exception e) {
                e.printStackTrace();
            }
            return null;
        }

        public void disconnect() {
            try {
                telnet.disconnect();
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
    }
        public static boolean testInet() {
            Socket sock = new Socket();
            String site = "google.com";
            InetSocketAddress addr = new InetSocketAddress(site, 80);
            try {
                sock.connect(addr, 3000);
                return true;
            } catch (IOException e) {
                return false;
            } finally {
                try {
                    sock.close();
                } catch (IOException e) {
                }
            }
        }

       private static String getTime()
        {
            return new SimpleDateFormat("yyyy-MM-dd_HH:mm:ss").format(Calendar.getInstance().getTime());
        }

        public static void main(String[] args) {
            String routerip;
            String username;
            String password;
            System.out.println("started at " + getTime());
            Scanner in = new Scanner(System.in);
            System.out.println("Input \n router ip: ");

            routerip = in.nextLine();
            System.out.println("login: ");
            username = in.nextLine();
            System.out.println("password: ");
            password = in.nextLine();

            System.out.println("Writen." +
                    "ip: " + routerip + "\n login: " + username
                    + "\n password: " + password + "\n");
            int i = 19;
            try {
                while (i > 0) {
                    System.out.println(".");
                    Thread.sleep(500);
                    i--;
                }
            } catch (InterruptedException ex) {
                ex.printStackTrace();
            }

            try {
                while (true) {
                    if (testInet() == false) {
                        System.out.println("\n no connection at " + getTime() + "\n rebooting... ");
                        AutomatedTelnetClient telnetClient = new
                                AutomatedTelnetClient(routerip, username, password);
                        telnetClient.sendCommand("reboot");
                        Thread.sleep(60 * 1000 * 3);
                    }
                    else
                        System.out.println("\n there is connection at " + getTime());
                    Thread.sleep(60*1000);

                }
            } catch (InterruptedException ex) {
                ex.printStackTrace();
            } finally {
                System.out.println("\n something wrong while connecting. " +
                        "\n Program will be closed.");
            }


        }

}