package auth.system;

/**
 *
 * @author Patrick
 */
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.util.Scanner;
import java.util.logging.Level;
import java.util.logging.Logger;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Paths;



public class AuthSystem {

    /**
     * @param args the command line arguments
     * @throws java.io.FileNotFoundException
     */
    public static void main(String[] args) throws FileNotFoundException, IOException {
        Scanner input = new Scanner(System.in);
        int attempts = 0;
        String username = "";
        String password = "";
        FileInputStream fileByteStream = null;
        Scanner inFS = null;
        String credString;


        // Loop to keep failed attempts under 3
        while (attempts < 3){
            try {
                System.out.print("Enter Username(\"exit\" to logout): ");
                username = input.nextLine();
                // This if statement gives the user a way to logout
                if(username.contains("exit")){
                    return;
                }
                System.out.print("Enter Password: ");
                password = input.nextLine();
                //import creds file
                fileByteStream = new FileInputStream("creds.text");
                inFS = new Scanner(fileByteStream);
                credString = "blank";


                //convert plaintext password from user to md5hash
                String original = password;
                MessageDigest md = MessageDigest.getInstance("MD5");
                md.update(original.getBytes());
                byte[] digest = md.digest();
                StringBuffer sb = new StringBuffer();
                for (byte b : digest) {
                    sb.append(String.format("%02x", b & 0xff));
                }


                //loop only while the inFS, which is reading the file line by line, is not null.
                //This way it exits the loop onces it reaches the end of the file.
            while(inFS.hasNextLine()){
                //kicks the loop out if the user fails more than 3 times
                if(attempts >= 3){
                    System.out.print("Login failure limit reached. Please contact an administrator to unlock your account.");
                    return;
                    }
                //Reading the next line in the file and splitting it into an array
                credString = inFS.nextLine();
                String arr[] = credString.split("\t");

                //comparing user input(username) to what's in the credString variable that's reading the creds file.
                if(credString.contains(username)){

                    //if the username passes it comes down here to test if the user plaintext password matches
                    //the MD5 hash we have in the creds file once converted
                    if (credString.contains(sb.toString())){
                        System.out.println("Login Successful");
                        System.out.println("");

                        //this reads into the array we made earlier to pull out the user role(admin, zookeeper, veterinarian)
                        String role = arr[3];
                        //Prints to screen the user role file
                        Files.lines(Paths.get(role + ".text")).forEach(System.out::println);
                        System.out.println("test");

                        //Resetting the failure count
                        attempts = 0;
                        System.exit(0);

                    }}
                }

                //If the username is not contained in the current credString it notifies the user of the failure
                //adds to the count for the loop to end and notifies the user of how many fails have happened since last login
                if (!credString.contains(username)) {
                    System.out.println("Login Failure");
                    attempts = attempts +1;
                    System.out.println("Failed attempts(max 3): " + attempts);

                    }


            }
            catch (NoSuchAlgorithmException ex) {
                Logger.getLogger(AuthSystem.class.getName()).log(Level.SEVERE, null, ex);
            }

        }

    }

}