import java.nio.charset.StandardCharsets;
import java.util.ArrayList;
import java.util.List;
import java.io.*;
import java.nio.file.*;
import java.util.Scanner;

/* @author Marilena Eleftheriou
 */
public class User
{
  private String name;
  private String surname;
  private String username;
  private String password;
  private int timesPlayed = 0;
  private int currentScore = 0;
  private int wrongAnswers = 0;
  private int questionsSkipped = 0;
  private int questionsAnswered = 0;
  private int highscore;
  private int userLine = -1;
  public static boolean Registration;

  private final static int MIN_USERNAME = 5; //sets minimum username characters to 5
  private final static int MIN_PASSWORD = 8; //sets minimum password characters to 8
  private final static int MAX_CHAR = 15; //sets maximum username and password characters to 15

  public User ()//allow user class to be called
  {
      this("","");
  }

  public User (String username, String password)//copy constructor that sets the username and password
  {
      this.username=username;
      this.password=password;
  }

  public void register()
  {

      Scanner scan = new Scanner(System.in);
      System.out.println("Enter your first name: ");
      this.name=scan.nextLine();
      System.out.println("Enter your last name: ");
      this.surname=scan.nextLine();

      setUsername();
      if (readUserData() == null) {
          setPassword();
          saveData();
      } else
      {
          this.username = "";
          System.out.println("Username already exists!");
      }

  }

  public String getName() //formats name
  {
      return (name + "," + surname);
  }

  public void setUsername()
  {
      boolean usernameError=false;
      Scanner scan = new Scanner(System.in);
      System.out.println("Enter a username between 5-15 characters:");
      username= scan.nextLine();
        while (username.length()<MIN_USERNAME)//checks if the username is too short
            {
             usernameError=true;
             System.out.println("Username too short");
             System.out.println("Try again: ");
             username= scan.nextLine();
            }
        while (username.length()>MAX_CHAR)//checks if the username is too long
            {
             usernameError=true;
             System.out.println("Username too long");
             System.out.println("Try again: ");
             username= scan.nextLine();
            }

        usernameError=false;
  }

  public void setPassword()
  {
      do
      {
      Scanner scan = new Scanner(System.in);
      System.out.println("Enter your password:");
      System.out.print("(Your password must have 8-15 characters");
      System.out.println("and must contain at least one letter and one digit)");
      password= scan.nextLine();
      }
      while ((password.length() < MIN_PASSWORD) || (password.length() > MAX_CHAR) || (!password.matches(".*[0-9]+.*")));

      System.out.println("You have now been registered!");

  }

  public String[] readUserData() //creates ArrayList of users
  {
      ArrayList<String> users = new ArrayList<String>();
      try (Scanner inputStream = new Scanner(new FileInputStream("userInfo.txt")))
      {
           while (inputStream.hasNextLine())
           {
               String line = inputStream.nextLine();
               users.add(line);
           }
       }
      catch(FileNotFoundException e)
      {
           return null;
       }

        int x = 0;
        for (String u : users)
        {
            String[] userInfo = u.split(",");
            if (userInfo[2].equals(username))
            {
                userLine = x;
                return userInfo;
            }
            x++;
        }

        return null;
  }

  public boolean isLoginCorrect()
  {
       String[] userData = readUserData();
       if (userData != null) {
           if (userData[3].equals(password))
           {
               highscore = Integer.parseInt(userData[5]);//converts String of highscore into int
               this.name = userData[0];
               this.surname = userData[1];
               this.timesPlayed = Integer.parseInt(userData[4]) + this.timesPlayed;
               return true;
           }
           return false;
       }
       return false;
   }

   public int getCurrentScore()
   {
       return this.currentScore;
   }

   public void increaseScore()//increases the current score for every correct answer
                              //and updates the high score if it is exceeded
   {
       currentScore++;
       if (currentScore > highscore)
       {
           highscore = currentScore;
       }
   }

   public void increaseWrongAnswers()
   {
       wrongAnswers++;
   }

   public void increaseQuestionsSkipped()
   {
       questionsSkipped++;
   }

   public void increaseTimesPlayed() //counter denoting times played
   {
       timesPlayed++;
   }

   public void reset ()
   {
       currentScore=0;
       wrongAnswers=0;
       questionsSkipped=0;
   }

   public void printResults()//prints out current stats
   {
       System.out.println("Questions Answered: " + (wrongAnswers + currentScore) + "/10");
       System.out.println("Questions Skipped: " + questionsSkipped + "/10" + "\n");
       System.out.println("Current Score: " + getCurrentScore() + "/10");
   }

   public void saveData()
   {
       String[] userData = readUserData();
       if (userData == null)
       {
            PrintWriter outputStream = null;
            try
            {
                outputStream = new PrintWriter(new FileOutputStream("userInfo.txt", true));
            }
            catch (FileNotFoundException e)
            {
                System.out.println("Error opening the file userInfo.txt.");
                System.exit(0);
            }
            outputStream.println(toString());

            outputStream.close();
       }
       else {
           try
           {
               Path path = Paths.get("userInfo.txt");
               List<String> lines = Files.readAllLines(path, StandardCharsets.UTF_8);
               lines.set(userLine, toString());
               Files.write(path, lines, StandardCharsets.UTF_8);
           }
           catch (IOException e)
           {
                System.out.println("Error updating values.");
                System.exit(0);
           }
       }
   }

  public String getUsername()
  {
      return this.username;
  }

  public String getPassword()
  {
      return this.password;
  }

  @Override
  public String toString()
  {
      return (getName() + "," + getUsername() + "," + getPassword() + "," + timesPlayed + "," + highscore);
  }
}