package authenticationsystem;

import java.io.BufferedReader;
import java.io.FileReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.util.Scanner;
// Import necessary classes

public class AuthenticationSystem{
    // Define the class AuthenticationSystem

    public static void main(String[] args) throws IOException{
        // Call the method login()
        login();
    }

public class ValidateCredentials{

    private boolean isValid;
    private String filePath;
    private String credentialsFileName;

    public ValidateCredentials(){
        isValid = false;
        filePath = "C:\\Users\\Owner\\My Documents\\NetBeansProjects\\AuthenticationSystem\\";
        credentialsFileName = "credentials";
    }

    public static boolean isCredentialsValid(String name, String pwd) throws Exception{
        unsuccessfulattempts--;
        System.out.println("Username:");
        String name = br.readLine();
        System.out.println("Password:");
        String pwd = br.readLine();
        String original = pwd;
        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));
        }
        System.out.println("");
        System.out.println("original:" + original);
        System.out.println("digested:" + sb.toString()); //sb.toString() is what you'll need to compare password strings

        isValid = readDataFiles(userName, sb.toString());

        return isValid;
    }

    public boolean readDataFiles(String userName, String passWord) throws IOException{
        FileInputStream fileByteStream1 = null; // File input stream
        FileInputStream fileByteStream2 = null; // File input stream

        Scanner inFS1 = null;                   // Scanner object
        Scanner inFS2 = null;                   // Scanner object

        String textLine = null;
        boolean foundCredentials = false;

        // Try to open file
        System.out.println("");
        System.out.println("Opening file " + credentialsFileName + ".txt");
        fileByteStream1 = new FileInputStream(filePath + "credentials.txt");
        inFS1 = new Scanner(fileByteStream1);

        System.out.println("");
        System.out.println("Reading lines of text.");

        while (inFS1.hasNextLine()){
            textLine = inFS1.nextLine();
            System.out.println(textLine);

            if (textLine.contains(userName) && textLine.contains(passWord)){
                foundCredentials = true;
                break;
            }
        }
        // Done with file, so try to close it
        System.out.println("");
        System.out.println("Closing file " + credentialsFileName + ".txt");

        if (textLine != null) {
            fileByteStream1.close(); // close() may throw IOException if fails
        }
        if (foundCredentials == true) {
            // Try to open file
            System.out.println("");
            System.out.println("Opening file " + userName + ".txt");
            fileByteStream2 = new FileInputStream(filePath + userName + ".txt");
            inFS2 = new Scanner(fileByteStream2);

            System.out.println("");

            while (inFS2.hasNextLine()) {
                textLine = inFS2.nextLine();
                System.out.println(textLine);
            }

            // Done with file, so try to close it
            System.out.println("");
            System.out.println("Closing file " + userName + ".txt");

            if (textLine != null) {
                fileByteStream2.close(); // close() may throw IOException if fails
            }
        }

        return foundCredentials;

    }

}

public static void login(){
    // Define the method login()
    String pwd = "";
    int flag = 0;
    // Declare the variables
    int unsuccessfulattempts = 3;
    // Declare and initialize the unsuccessfulattempts to 3
    BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
    //Create object 'br' to read the input from the user
    System.out.println("Authentication System");
    // Display the Header of the program
    try{
        do{
            if (flag == 0){
            // The conditional statement that checks the username and password
                isCredentialsValid();
                // Call isCredentialsValid() method
                break;
            }
            if(unsuccessfulattempts == 0){
            // Checks if the user enters more then 3 attempts.
                System.out.println("You are attempting to login more than three times");
                System.out.println("You are out of attempts " + "Exiting!");
                System.exit(1);
            }
            else{
            // If condition is false, have user try submitting credentials again
            System.out.println("Invalid Username or Password.");
            System.out.println("Please try again.");
            System.out.println(unsuccessfulattempts + " more attemptes left.\n");
            }
        }

    while(unsuccessfulattempts>0);{

        catch (NoSuchAlgorithmException e){
            e.printStackTrace();
        }

        catch (IOException e){
            e.printStackTrace();
        }
    }

public static void authorization(){
// Create authorization() method
    String userLogOut;
    Scanner scnr = new Scanner(System.in);
    // Get a string from the user to logout by creating Scanner object
    System.out.println("\n\tWelcome Admin\t");
    System.out.println("Press EXIT for logout\n");

        do{
            userLogOut = scnr.nextLine();
            // Take input from the user until they enter EXIT
        }

    while(!userLogOut.equals("EXIT"));{

        if(userLogOut.equals("EXIT")){
        // If user enters EXIT to logout
            login();
            // Call the method login() to enter the credentials
        }
    }
}