import java.util.ArrayList;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.util.Scanner;

/** User login accounting program.
 *  Let's read a text file containing a server log.  Each line contains
 *  information about 1 login session.  On this line of text, the first
 *  word is the username.  For now, let's ignore the rest of the line.
 *  We are interested in keeping track of ALL users and finding out the
 *  total number of times EACH person has logged in.
 *  This program features an ArrayList, because we don't know in advance
 *  how many users there have been.
 */
public class Driver
{
  public static void main(String [] args) throws FileNotFoundException
  {
    // To make the program more concise, let's assume the name of the
    // input file is ultra1.txt.
    Scanner in = new Scanner(new FileInputStream("ultrax1.txt"));

    // We need an ArrayList to store users.
    ArrayList<User> list = new ArrayList<User>();

    // For each line in the file, we have a new login to take care of.
    // We want to stop once we read a blank line or there are no more lines.
    while (in.hasNextLine())
    {
      String line = in.nextLine();
      if (line.equals(""))
        break;

      // At this point we know the line is not blank.
      // Scan this line so we can read the first word.
      Scanner lineScanner = new Scanner(line);
      String userName = lineScanner.next();

      // Now we have the name of the user associated with this login session.
      // Question:  Have we seen this user listed already?
      //   If so, find the user, and add 1 to that person's login count.
      //   If not, create a new user, add to list, and start login count at 1.
      
      // Look thru the list and see if we have this name.
      boolean found = false;
      for (int i = 0; i < list.size(); ++i)
        if (list.get(i).getName().equals(userName))
        {
          // I found the name in the list!
          // The object list.get(i) is the user object in question,
          // so all we need to do is add 1 to its number of logins.  
          list.get(i).addLogin();
          found = true;
          break;
        }

      // If UNsuccessful in finding the user in the list, create new user,
      //   and append to the list.
      if (! found)
      {
        User newUser = new User(userName, 1);
        list.add(newUser);					// don't forget!
      }
    }

    // We're done reading the file.
    // Output the list.
    System.out.printf("There are %d users.\n", list.size());
    System.out.printf("Here are the user login totals per user:\n\n");

    // loop to sum
    int sum = 0;
    for (int i = 0; i < list.size(); ++i)
      sum += list.get(i).getNumLogins();
    System.out.printf("I found a total of %d logins.\n", sum);

    // Sort the ArrayList by the number of logins.  Descending.
    for (int i = 0; i < list.size(); ++i)
      for (int j = i+1; j < list.size(); ++j)
      {
        if (list.get(i).getNumLogins() < list.get(j).getNumLogins())
        {
          User temp = list.get(i);
                              // WRONG:  list.get(i) = list.get(j)
          list.set(i, list.get(j));
                              // WRONG:  list.get(j) = temp;
          list.set(j, temp);
        }
      }

    // Print out the list in an attractive format.
    for (int i = 0; i < list.size(); ++i)
      System.out.printf("%s\n", list.get(i).toString());

    // Query:  the user will enter a name, and we'll look that person
    //   up in the list and print out that persons' # of logins
    Scanner kbd = new Scanner (System.in);
    System.out.printf("Enter a name:  ");
    String desiredName = kbd.next();

    boolean found = false;
    for (int i = 0; i < list.size(); ++i)
    {
      if (desiredName.equals(list.get(i).getName()))
      {
        found = true;
        System.out.printf("%s logged in %d times.\n",
                          desiredName,
                          list.get(i).getNumLogins());
      }
    }
    if (! found)
      System.out.printf("That user never logged in.\n");

  }
}