import java.io.*;
import java.util.Scanner;

public class FileReaderCustom {
    Scanner choiceM = new Scanner(System.in);

    public void showMenu(){

        int choice;
        System.out.println("Please chose your action \n 1. Add new Number \n 2.Read existing numbers");
        choice = choiceM.nextInt();

        if( choice == 1 ){
            //Append to list
            int num_to_wrtite;
            System.out.println("Enter phone to save");
            num_to_wrtite = choiceM.nextInt();
            writeFile( num_to_wrtite );

        }else if (choice == 2){
            //show existing numbers
            readerFile();
        }else {
            System.out.println("Wrong choice");
        }
    }

    public void readerFile(){
        try {
            FileReader reader = new FileReader("phones.txt");
            BufferedReader br = new BufferedReader(reader);

            String readNumbers = "";
            System.out.println("Reading numbers.....");

            while ((readNumbers = br.readLine()) != null) {
                System.out.println(readNumbers);
            }
            reader.close();

        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    public void writeFile( int num){
        try(FileWriter fw = new FileWriter("phones.txt", true);
            BufferedWriter bw = new BufferedWriter(fw);
            PrintWriter out = new PrintWriter(bw))
        {
            out.println(num);

        } catch (IOException e) {
            //exception handling left as an exercise for the reader
            System.out.print(" error processing file");
            e.printStackTrace();
        }
    }

    public static void main(String [] args){

        FileReaderCustom fo = new FileReaderCustom();
        fo.showMenu();
    }

}