// I imported the Scanner class so that I can accept userInput
import java.util.Scanner;

public class Test {

    public static void main(String[] args) {

        //****INITIALIZING VARIABLES****//

        /* Variables are initialized up here so that they can easily be found and changed for tests.
         * I initialized the Scanner and assigned it to a variable name "userInput" to make it usable in the
         * rest of the program. */
        Scanner userInput = new Scanner(System.in);
        /* These checks will be referred upon to check how many times the password contains an upper case
         * letter(upCheck), a lower case letter(loCheck), a number(nrCheck) and a symbol(syCheck).*/
        int upCheck, loCheck, nrCheck, syCheck;

        /* These checks will be referred upon when checking how many times the appropriate character is
         * followed by a different character making the password stronger.*/
        int upCheck2, loCheck2, nrCheck2, syCheck2;

        //****OBTAINING INFORMATION FROM USER****//

        /* I prompt the user to enter his/her email address which will be stored in the variable "email".
         * This is so that I can check whether or not the password contains part of the email address. */
        System.out.printf("%-51s", "Enter your email address");
        String email = userInput.nextLine();
        /* I grab the index of the @ sign in the email which is used as the last parameter in obtaining
         * the user name of the user through the substring method.*/
        int atSign = email.indexOf('@');
        /* If there is no @ symbol in the email, the variable atSign will return -1. This means that
         * obtaining the user name of the email will be impossible. I fix this by figuring out of
         * atSign is -1 and if it is, it will continually prompt the user until they enter a valid
         * email address containing the @ symbol.*/
        while (atSign == -1) {
            System.out.printf("%-51s", "Please enter a valid email address");
            email = userInput.nextLine();
            atSign = email.indexOf('@');
        }
        String username = email.substring(0, atSign);
        /* I then prompt the user to enter his/her year of birth. Later on in the program, I will be testing
         * to see if the password contains the last two digits of the user's year of birth. */
        System.out.printf("%-51s", "Enter your year of birth");
        String birth = userInput.nextLine();
        /* I check to see if the birth year's length is 4. If it is not, it is not a valid birth year. I then
         * continue to prompt the user for a proper birth year.*/
        while (birth.length() != 4) {
            System.out.printf("%-51s", "Please enter a valid birth year");
            birth = userInput.nextLine();
        }
        /* The next variable pulls the last two numbers from the user's birth year. The last two numbers are
         * needed to check if they are in the password, which would make the password Invalid.class */
        String birth2 = birth.substring(2, 4);
        /* The last prompt asks the user for their password. Without this piece of information, this program
         * would not exist */
        System.out.printf("%-51s", "Enter your password");
        String password = userInput.nextLine();

        //****PASSWORD VERIFICATION****//

        // Sets the password check to true to make sure that the following while loop actually runs
        boolean pCheck = true;
        /* The "mainloop:" is used as a check point that the program can refer back to. There is many times
         * when the program is nested inside the while loop and then nested again into an if statement. If I
         * were to put a simple "continue;" inside of the if statement, the loop would continue inside the
         * nested for loop rather than going all the way out of the for loop and outside the while loop. */
        mainloop:
        while (pCheck == true) {
            /* I needed to set the variables back to 0 inside the while loop other wise the checks would keep
             * being added up if the program needs to go back to the beginning of the while loop. */
            upCheck = 0;
            loCheck = 0;
            nrCheck = 0;
            syCheck = 0;

            upCheck2 = 0;
            loCheck2 = 0;
            nrCheck2 = 0;
            syCheck2 = 0;

            // I created a for loop that is long enough to iterate through every single character of the password.
            for (int i = 0; i < password.length() - 1; i++) {
                /* The next four statements test to see if the password is the right length, there is no
                 * whitespace, it does not contain the last two digits in the birth year and that it does not
                 * contain the beginning part of the email. If any of these are incorrect, it prompts the user to
                 * enter a new password */
                if (password.length() < 8 || password.length() > 12) {
                    System.out.println("Invalid!");
                    System.out.printf("%-51s", "Your password needs to be between 8 and 12 characters:");
                    password = userInput.nextLine();
                    //The next line is the part that allows me to go back to the "mainloop:" I was talking about earlier.
                    continue mainloop;
                }
                if (Character.isWhitespace(password.charAt(i))) {
                    System.out.println("Invalid!");
                    System.out.printf("%-51s", "Please enter a password without white spaces:");
                    password = userInput.nextLine();
                    continue mainloop;
                }
                if (password.contains(birth2)) {
                    System.out.println("Invalid!");
                    System.out.printf("%-51s", "Your password cannot contain your birth year:");
                    password = userInput.nextLine();
                    continue mainloop;
                }
                if (password.toLowerCase().contains(username.toLowerCase())) {
                    System.out.println("Invalid!");
                    System.out.printf("%-51s", "Your password cannot contain part of your email:");
                    password = userInput.nextLine();
                    continue mainloop;
                }

                /* I added if statements that check if the character that is being checked is upper case,
                 * lower case, a number or a symbol.
                 */
                if (Character.isUpperCase(password.charAt(i))) {
                    upCheck++;
                    /* If the character is anything other than the afformentioned check, then I add one to the
                     * second check that checks to see how strong the password is. */
                    if (!(Character.isUpperCase(password.charAt(i + 1)))) {
                        upCheck2++;
                    }
                }
                if (Character.isLowerCase(password.charAt(i))) {
                    loCheck++;
                    if (!(Character.isLowerCase(password.charAt(i + 1)))) {
                        loCheck2++;
                    }
                }
                if (Character.isDigit(password.charAt(i))) {
                    nrCheck++;
                    if (!(Character.isDigit(password.charAt(i + 1)))) {
                        nrCheck2++;
                    }
                }
                if (password.charAt(i) >= 33 && password.charAt(i) <= 47 || password.charAt(i) >= 58 && password.charAt(i) <= 64 || password.charAt(i) >= 91 && password.charAt(i) <= 96 || password.charAt(i) >= 123) {
                    syCheck++;
                    if (!(password.charAt(i + 1) >= 33 && password.charAt(i + 1) <= 47 || password.charAt(i + 1) >= 58 && password.charAt(i + 1) <= 64 || password.charAt(i + 1) >= 91 && password.charAt(i + 1) <= 96 || password.charAt(i + 1) >= 123)) {
                        syCheck2++;
                    }
                }
            }
            // I closed the scanner because the yellow caution thing was bothering me.
            userInput.close();
            // After the for loop is done, this means that all the password checks have been done, so I can stop the while loop now.
            pCheck = false;
            // This last part of the program checks to see how strong the password is and prints out accordingly.
            if (upCheck >= 2 && loCheck >= 2 && nrCheck >= 2 && syCheck >= 2 && upCheck2 >= 2 && loCheck2 >= 2 && nrCheck2 >= 2 && syCheck2 >= 2) {
                System.out.println("Your password is strong");
            }
            if (upCheck >= 2 && syCheck >= 1) {
                System.out.println("Your password is average");
            } else {
                System.out.println("Your password is weak");
            }
        }
    }
}