package de.cornelius.may.telnet;

import de.cornelius.may.Bot;
import lombok.Getter;
import org.jetbrains.annotations.NotNull;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.Socket;
import java.util.Objects;
import java.util.concurrent.*;

public class Telnet {

    @Getter
    private String host;

    @Getter
    private int port;

    @Getter
    private String confirmationString;

    private boolean connected;
    private Socket socket;
    private PrintWriter out;
    private BufferedReader in;

    public Telnet(String host, int port, String confirmationString) throws IOException {
        this.host = host;
        this.port = port;
        this.confirmationString = confirmationString;
        socket = new Socket(host, port);
        out = new PrintWriter(socket.getOutputStream(), true);
        in = new BufferedReader(new InputStreamReader(socket.getInputStream()));
        connected = true;
        Bot.getLogManager().info("Connected telnet: \n");
        while(in.ready()) {
            String line = in.readLine();
            if(line.equals("")) continue;
            Bot.getLogManager().info(line);
        }
    }

    public synchronized void close() throws IOException {
        if(!connected) throw new IllegalArgumentException("Not connected!");
        connected = false;
        out.close();
        in.close();
        socket.close();
    }

    public synchronized String sendCommand(String command) {
        out.println(command);
        try {
            Future<Object> response = Bot.getPool().submit(getResponse);
            return response.get(1, TimeUnit.MINUTES).toString();
        } catch (InterruptedException | ExecutionException | TimeoutException ex) {
            Bot.getLogManager().error("Error while getting response for command '" + command + "'", ex);
        }
        return null;
    }

    private Callable<Object> getResponse = new Callable<Object>() {
        @NotNull
        public Object call() {
            StringBuilder responseBuilder = new StringBuilder();
            while(true) {
                String line = null;
                try {
                    line = in.readLine();
                } catch (IOException ex) {
                    Bot.getLogManager().error("Error while reading response line", ex);
                }
                if(Objects.equals(line, "") || Objects.equals(line, "\r\n")) continue;
                responseBuilder.append(line).append("\n");
                if(Objects.equals(line, confirmationString)) break;
            }
            String response = responseBuilder.toString();
            return response.substring(0, (response.length() - 1));
        }
    };
}