package projekt1;
import java.util.*;

public class AccessControlCode {
	public static Scanner scan = new Scanner(System.in);
	public static void main(String[] args) {
		String username = createUsername();
		String password = passwordChange();
		// Logon
		while (true) {
			logOn(username, password);
			while(true) {
				System.out.println("You now have the following choices:\r\n" +
						" 1 - Change Password\r\n" +
						" 2 - Log off\r\n" +
						" 3 - Shut down");
				System.out.println("Please select:");
				int choice = scan.nextInt();
				scan.nextLine();
				if (choice == 1) {
					password = passwordChange();
					System.out.println("*** Password changed for user " + username);
				}
				if (choice == 2) {
					System.out.println("*** User " + username + " is logged off");
					while(true) {
						System.out.println("To logon enter username:");
						String musername = scan.nextLine();
						if (username.equals(musername)) {
							break;
						}
					}
					int t = 3;
					while (true) {
						t--;
						System.out.println("To logon enter password:");
						String mpassword = scan.nextLine();
						if (password.equals(mpassword)) {
							System.out.println("*** User " + username + " is Logged on.");
							break;
						}
						if (t == 0 ) {
							System.exit(0);
						}
					}
				}

				if (choice == 3) {
					System.out.println("*** User " + username + " is logged off");
					System.out.println("*** System shutting down.");
					System.exit(0);
				}
			}
		}
	}
	public static String createUsername() {
		while(true) {
			System.out.println("Please enter a non-empty username:");
			String username = scan.nextLine();
			if (Character.isLetter(username.charAt(0)) && !(username.contains(" ")) ) {
				return username;
			}
		}
	}
	// Change/Create password
	public static String passwordChange() {
		while(true) {
			System.out.println("Please enter a password    :");
			String password = scan.nextLine();
			if (checkPWD(password)) {
				System.out.println("Please repeat the password :");
				String onePassword = scan.nextLine();
				if (checkPWD(onePassword) == true && onePassword.equals(password)) {
						return password;
				}
			}
		}
	}
	public static boolean checkPWD(String password) {
		int PWlen = password.length();
		boolean hasNonAlpha = password.matches("^.*[^a-zA-Z0-9 ].*");
		boolean hasTwoNumbers = password.matches("(.*\\d+.*){2}");
		boolean atleastTwoAlpha = password.matches("(.*[a-zA-Z]+.*){2}");
		boolean hasOneCapital = password.matches("^.*[A-Z].*");
		boolean hasOneLower = password.matches("^.*[a-z].*");
		if (PWlen >= 8 && hasNonAlpha == false && hasTwoNumbers == true
				&& hasOneCapital == true && atleastTwoAlpha == true && hasOneLower == true) {
			return true;
		}
		else {
			return false;
		}
	}
	public static void logOn(String username, String password) {
		System.out.println("*** User " + username +  " is registered.");
		while(true) {
			System.out.println("To logon enter username: ");
			String musername = scan.nextLine();
			if (username.equals(musername)) {
				break;
			}
		}
		while (true) {
			System.out.println("To logon enter password:");
			String mpassword = scan.nextLine();
			if (password.equals(mpassword)) {
				System.out.println("*** User " + username + " is Logged on.");
				break;
			}
		}
	}
}