import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.PrintWriter;
import java.util.*;
import java.util.ArrayList;


public class Driver {


	static ArrayList<Driver> userInfoArray = new ArrayList<Driver>();
		   public String username;
		   public String password;

		   public Driver (){

		   }

		   public Driver (String args_username, String args_password){
			   username = args_username;
			   password = args_password;
		   }

		   // getter methods
			public String getUserName(){
				return username;
			}

			public String getPassword(){
				return password;
			}

			// setter methods
			public void setUserName(String args_username){
				username = args_username;
			}

			public void setPassword(String args_password){
				password = args_password;
			}

		public static void main(String[] args) {

			//load();

			Driver d = new Driver();

			Scanner inputChoice = new Scanner(System.in);
			Scanner inputUserName = new Scanner(System.in);
			Scanner inputPassword = new Scanner(System.in);

			System.out.println("*** Welcome to HR Management System. ***" + "\n" + "\n" + "\n");
			System.out.println("If you have an existing account            1" + "\n");
			System.out.println("If you want to create a new account        2" + "\n");
			System.out.println("Exit Program            X" + "\n");

			Scanner menuValue = new Scanner(System.in);
			String enteredValue = "";


			do {

				System.out.println("Enter a value");
				enteredValue = menuValue.next();

				switch (enteredValue) {
				case "1":
					System.out.println("Existing Account");

					System.out.println("Enter the username: ");
			    	d.username = inputUserName.nextLine();

					if (d.username.isEmpty()) {
						System.out.println("\nNothing was entered for the UserName, Please try again.");
						d.username = inputUserName.nextLine();
					}

					if (!(d.username.isEmpty()) && d.userNameDuplicate(d.username)){
				    	System.out.println("Enter the password: ");
				    	d.password = inputPassword.nextLine();

						//check if password is correct
				    	System.out.println(d.getUserInfo(d.username).getPassword());
						if (d.password.equals(d.getUserInfo(d.username).getPassword())){
							// password matches
							System.out.println("You are logged in");
						} else {
							System.out.println("Password does not match ");
						}

					} else {
						System.out.println("This username does not exist");
					}


					break;
				case "2":
					System.out.println("Creating Account");

			    	System.out.println("Enter the username: ");
			    	d.username = inputUserName.nextLine();

					if (d.username.isEmpty()) {
						System.out.println("\nNothing was entered for the UserName, Please try again.");
						d.username = inputUserName.nextLine();
					}

			    	//check for username duplicity
			    	if (!(d.username.isEmpty()) && !(d.userNameDuplicate(d.username))){
			    		//continue

				    	System.out.println("Enter the password: ");
				    	d.password = inputPassword.nextLine();
			    	} else {
			    		System.out.println("UserName already exist, Choose another User Name");
			    	}

			    	//adding user details to the array list
			    	Driver d1 = new Driver(d.username,d.password);
			    	d.userInfoArray.add(d1);
					break;

				case "X":
				case "x":
/*
					try{
					FileWriting();
					System.out.println("Save and Exit");
					} catch (FileNotFoundException fe){
						//throw OfferException("File Not Found");
						System.out.println("File Not Found" );
					}
*/				}

			} while (!(enteredValue.toUpperCase().equals("X")));


		}


		//checks if the username exists in the arraylist

		public boolean userNameDuplicate(String arg_username) {

			boolean userNameFound = false;

			//System.out.println("In if duplicate check Array Size"+userInfoArray.size());

			for (int i = 0; i < userInfoArray.size(); i++) {

				String currentUserName = ((Driver) userInfoArray.get(i)).getUserName();

				if (arg_username.toUpperCase().equals(currentUserName.toUpperCase())) {

					userNameFound = true;
					break;

				} else {
					userNameFound = false;
				}
			}

			return userNameFound;
		}


		public Driver getUserInfo(String arg_username) {
			for (Driver d0 : userInfoArray) {
				if (d0.getUserName().toUpperCase().equals(arg_username.toUpperCase())) {
					return d0;
				}
			}

			return null;
		}


		/*Writing arraylist into a file
		 *
		 */
		public static void FileWriting() throws FileNotFoundException {
			// TODO Auto-generated method stub
			String filename = "backup.txt"; // path & filename
			//C:\Users\Dhiraj\workspace\Sem2\SEF
			PrintWriter outputStream = null;

			try {
				// create a new object of the printWriter class & assign to the
				// Object variable
				outputStream = new PrintWriter(new FileOutputStream(filename));

				for (Driver d0 : userInfoArray) {
						outputStream.print(d0.getUserName()+ ",");
						outputStream.print(d0.getPassword());
						outputStream.println();
				}
				System.out.println("Yeah! File was written to without error");

			} catch (FileNotFoundException e) {
				// display the inbuilt error message belonging to e object
				System.out.println(e);
			} // end try catch
			outputStream.close(); // close the stream
		}


		//load values from the txt file
		private static void load() {
			Scanner inputStream = null; // create object variable

			try { // create Scanner object & assign to variable
				inputStream = new Scanner(new File("backup.txt"));
				inputStream.useDelimiter(",");
			} catch (FileNotFoundException e) {
				System.out.println("No User Infomation was Loaded");
				//System.exit(0);
				return;
			}

			try{
				while (inputStream.hasNext()) {
							System.out.println(inputStream.toString());
				          String readUserName = inputStream.next();
				          String readPassword = inputStream.next();

				          Driver d1 = new Driver(readUserName, readPassword);

				          userInfoArray.add(d1);

				}
			} catch (IllegalStateException e){
				System.err.println("Could not read from the file");
			} catch (InputMismatchException e){
				System.err.println("Something wrong happened while reading the file");
			}
			inputStream.close();
		}
}