package org.Exceptions;

import java.util.regex.Pattern;

public class RuntimeExceptionDemo {
    public static void main(String[] args) {

        UserEntity user = new UserEntity("Ali", "Ahmadi", 1234567890L,
                null, 989111111111L, null);

        // 1. Handle NullPointerException / IllegalArgumentException
        try {
            validateEmail(user);
        } catch (NullPointerException e) {
            System.err.println("Caught NullPointerException: Email string cannot be null.");
        } catch (IllegalArgumentException e) {
            System.err.println("Caught IllegalArgumentException: " + e.getMessage());
        }

        // 2. Handle ArithmeticException
        try {
            calculatePayment(5000, 0);
        } catch (ArithmeticException e) {
            System.err.println("Caught ArithmeticException: Cannot divide payment by zero installments.");
        }

        // 3. Handle NumberFormatException
        try {
            convertUserAge("twenty");
        } catch (NumberFormatException e) {
            System.err.println("Caught NumberFormatException: Could not parse invalid age string.");
        }

        // 4. Handle IllegalStateException
        try {
            completeRegistration(user);
        } catch (IllegalStateException e) {
            System.err.println("Caught IllegalStateException: " + e.getMessage());
        }

        System.out.println("\nRuntimeExceptionDemo executed completely and safely!");
    }

    public static void validateEmail(UserEntity user) {
        String email = user.getEmail();

        // Fix to prevent immediate NullPointerException before regex matching
        if (email == null) {
            throw new NullPointerException("Email cannot be null");
        }

        String emailRegex = "^[A-Za-z0-9+_.-]+@[A-Za-z0-9.-]+$";

        if (!Pattern.matches(emailRegex, email)) {
            throw new IllegalArgumentException("Invalid email format");
        }

        System.out.println("User email is valid");
    }

    public static void calculatePayment(int totalAmount, int installmentCount) {
        int payment = totalAmount / installmentCount;
        System.out.println("Each installment : " + payment);
    }

    public static void convertUserAge(String ageInput) {
        int age = Integer.parseInt(ageInput);
        System.out.println("User age: " + age);
    }

    public static void completeRegistration(UserEntity user) {
        if (user.getDateOfBirth() == null) {
            throw new IllegalStateException(
                    "Registration cannot be completed. Date of birth is missing."
            );
        }
        System.out.println("Registration completed");
    }
}