package java_assessment_1;

import java.util.regex.Pattern;
import javax.swing.JOptionPane;
import java.util.Scanner;
/**
 *
 * @author 30054547
 */
public class Java_Assessment_1 {
    //create a global string variable called logonID for later use
    String logonID;
    public static void main(String[] args) {
        //create a new instance of the program in the memory
        Java_Assessment_1 prog = new Java_Assessment_1();
        prog.logon();
    }


    public void logon(){
        //create a variable called logonID and take their attempt at the logon
        logonID = JOptionPane.showInputDialog("please enter your logon ID");
        //check if their attempt is correct and either let them on or tell them their attempt is wrong
        if(logonID == null){
            System.exit(0);
        }
        if((logonID.equals(" ") || logonID.isEmpty())){
         JOptionPane.showMessageDialog(null,"please enter a logonID");
         logon();
        }
        if(logonID.length()!= 4){
           JOptionPane.showMessageDialog(null,"please enter a 4 character logon ID");
           logon();
        }
        if(logonID.equals("1234")) {
            menu();
        }
        else JOptionPane.showMessageDialog(null,"incorrect logon ID");
        logon();
    }

    public void menu(){
        //use the int choice to ask which option they would like to use and run the correct method according
        //to their input
        String choice;

        choice = JOptionPane.showInputDialog(null,"hello user " +logonID+" \nEnter 1 for user name \nEnter 2 for factorial \nEnter 3 to exit");
        //use if statements to decide which method to run
            if(choice == null){
        System.exit(0);
    }
        if ("1".equals(choice)) {
            userName();
        }
        if ("2".equals(choice)) {
            factorialResult();
        }
        if ("3".equals(choice)) {
            System.exit(0);
        }
        //display an error if the input does not match any of the options
        if (!"3".equals(choice) && !"2".equals(choice) && !"1".equals(choice)){
            JOptionPane.showMessageDialog(null,"please enter a valid input");
            menu();
        }
    }

    public void userName(){
        //ask them their full name and store it for later use
        String fullName;
        fullName = JOptionPane.showInputDialog(null,"hello user "+logonID+" what is your full name?");
        if(fullName == null){
            System.exit(0);
        }

        //carry the variable to the next method
        createUser(fullName);
    }

    public void createUser(String pFullName) {
        //use a substring to find their first initial
        String firstInitial = pFullName.substring(0,1);
        //find the position of the space between their names
        //int spacePos = pFullName.indexOf(" ");
        Scanner spaceScan = new Scanner(System.in);
        String spacePos = spaceScan.next();
        //System.out.println(s.indexOf(' '));

        //use an if to make sure there is a space in the name
        if(pFullName.contains(" ") && Pattern.matches("[a-zA-Z]+", pFullName) == false ){
            JOptionPane.showMessageDialog(null,"please enter a valid name");
            userName();
        }
        //use the space position to find their second name then create their username
        String surName = pFullName.substring((spacePos+1));
        String userName = firstInitial + surName;

        JOptionPane.showMessageDialog(null,"your username is " + userName);
        menu();
        }


    public void factorialResult(){
    //intialise your variables
     String input;
     int factorial = 0;
     int count = 0;

     //take in the number to be used in the factorial
     input = JOptionPane.showInputDialog("hello user "+logonID+"\nplease enter a number to use in a factorial");
    if(input == null){
        System.exit(0);
    }
     //perform various checks to see if the user has entered a valid number
     if(Pattern.matches(".*[a-zA-Z]+.*", input) == true || input.contains(" ") || input.contains(".")){
         JOptionPane.showMessageDialog(null,"plese enter a valid number");
         menu();
     }
     //put the input into an integer to perform further checks then calculate the factorial
        int number = Integer.parseInt(input);

        if(number == 0 || number == 1){
            JOptionPane.showMessageDialog(null, "the facrtorial of your number is 1");
            menu();
        }
        if(number < 0){
            JOptionPane.showMessageDialog(null,"please enter a positive number");
            menu();
        }

     //use this code to calculate the factorial by multiplying with the number below until the count goes down all the way
     factorial = number;
     while(count != 1){
        count = (number - 1);
         factorial = count * factorial;
        number = number - 1;
    }
     //display the users factorial and return back to the menu
     JOptionPane.showMessageDialog(null,"the factorial of your number is " + factorial);
     menu();
       }

}