import java.util.Scanner;

/** This is a Java application that, given as input a name in the form
**  
**             <firstName> <middleName> <lastName>
**
**  (where each of the names is a non-empty sequence of non-space characters
**  and a single space occurs on either side of the middle name), produces
**  as output the same name, but converted into the form
**
**             <lastName>, <firstName> <middleInitial>.
**
**  For example, provided as input
**
**             "Mary Barbara Smith"
**
**  the program will produce as output
**
**             "Smith, Mary B."
**
**  It is different from the original version of this application
**  in that it makes more extensive use of methods.
*/

public class NameConversion2 {

   // Create a Scanner that interprets input entered on the keyboard.
   private static Scanner keyboard = new Scanner(System.in);


   public static void main(String[] args)
   {
      // Declare symbolic constant for special characters.
      final char DOLLAR_SIGN = '$';

      String userPrompt = "Enter name (in format <first> <middle> <last>): ";
      String inName = getUserResponse(userPrompt);

      String outName = convertedName(inName);

      // Print a message that reports the input and output names.
      // Dollar signs are shown on either side of each name for the purpose
      // of verifying that no leading or trailing spaces exist within them.
      System.out.println("Input name:  " + DOLLAR_SIGN + inName + DOLLAR_SIGN);
      System.out.println("Output name: " + DOLLAR_SIGN + outName + DOLLAR_SIGN);
   }

         
   /* Given (via its argument) a name in the form <first> <middle> <last>,
   ** returns the same name, but converted into the form 
   ** <last>, <first> <middle init>.
   */
   private static String convertedName(String name)
   {
      // Declare symbolic constants for special characters.
      final char SPACE = ' ';
      final char COMMA = ',';
      final char PERIOD = '.';

      // Determine the position of the space in between first and middle names.
      int posOfFirstSpace = name.indexOf(SPACE);

      // The first name is the prefix ending at the position preceding
      // the first occurrence of a space.
      String firstName = name.substring(0, posOfFirstSpace);

      // The middle initial is the character at the position immediately
      // following the first occurrence of a space.
      char midInit = name.charAt(posOfFirstSpace + 1);

      // The last name is the suffix beginning at the position immediately
      // following the last occurrence of a space.
      String lastName = name.substring(name.lastIndexOf(SPACE)+1, name.length());
      // Note: Rather than finding the position of the last occurrence of a
      // space (as we did by using lastIndex() above), we instead could have 
      // found the position of the second occurrence of a space by using
      // indexOf() as follows: name.indexOf(SPACE, posOfFirstSpace+1) .
      // (We are assuming that there are exactly two spaces in the given
      // name, so the second occurrence of a space coincides with the last
      // occurrence.)

      // The string to be returned is obtained by concatenating lastName,
      // comma, etc., etc.
      return lastName + COMMA + SPACE + firstName + SPACE + midInit + PERIOD;
   }


   /* Prompts the user (by displaying the String provided via the argument)
   ** and returns the string entered at the keyboard in response. 
   */
   private static String getUserResponse(String prompt)
   {
      // Display the provided prompt.
      System.out.print(prompt);

      // Read and return the user's response. 
      return keyboard.nextLine();
   }
}