/* ************** Project 4 Advanced Version **************
       ********* Instructor : Professor Zdravko Markov *********
       ********* Submitted By : Salahuddin Akand *********
       ********* Date : July 1st, 2000 *********          
           ********* Course No : CS500 *********
     *** This program reads student information from keyboard ***
     *** and it can sort Students by Student's name ***  
     *** or it can sort Students by their GPA ***
     *** by using methods from student class *** */


import student;
import java.io.*;
import java.util.*;

class use_student{

public static void main (String[] args ) throws IOException {

    //Declare variables

    int  swap = 0, i, n= 0, j = 0 , option = 1,sort;
    String  [] a  = new String [100];
    String s1,s2,s3,s4,s5,s6,s7;


    BufferedReader stdin;
    stdin = new BufferedReader (new InputStreamReader (System.in));

    student [] st = new student [100];
    student t; 

    //Take input from user

    while (option == 1)
    {
      System.out.println ("Enter student name, three course no and grades separated by comma: " + "\n" +
                          "Ex: John Smith,CS111,A,CS112,B+,CS114,A- (lower case acceptable): " );

      StringTokenizer str = new StringTokenizer(stdin.readLine(),",");

      while (str.hasMoreTokens()) 
       {
         a[n] = str.nextToken().toUpperCase();
         n = n + 1;
       }
        s1=a[0]; s2=a[1]; s3=a[2]; s4=a[3]; s5=a[4]; s6=a[5];s7=a[6];
        st[j] = new student (s1,s2,s3,s4,s5,s6,s7);

        System.out.print ("Enter 1 for new student, 2 to continue : ");             
        option = Integer.parseInt (stdin.readLine());
        
        if (option == 1)
          { 
            n = 0;
            j = j + 1;
          }
        else 
          option = 2; 
   }

   //Print student information
      for (i=0; i < (j + 1) ; i++) 
      {
	System.out.println (st[i].get_info());
	System.out.println ("GPA is : " +st[i].get_gpa());
      }
	

  // Give option for multiple sorting  

  option = 4;
  while (option == 4)
   {
       System.out.print ("Enter 6 to sort by  student name, enter 7 to sort by GPA : ");             
       sort = Integer.parseInt (stdin.readLine());

        if (sort == 6)   // Sort by student name using bubble sort method
         { 
           do 
           { swap = 0; 

             for (i=0; i < j ; i++) 
             {
               if (st[i].get_name().compareTo(st[i+1].get_name()) > 0) 
                {  
                  t = st[i]; 
                  st[i] = st[i+1]; 
                  st[i+1] = t; 
                  swap++;
                }
             }
           } while (swap>0);   //end of first sort

            System.out.println ("\nSorted by student name in ascending order: " );

            for (i=0; i < j + 1; i++)  //print student sorted by name
            {
             System.out.println (st[i].get_name() + "   " + st[i].get_gpa());
            }                
            sort = 100;
         } 

        else if (sort == 7)  //sort by student GPA using bubble sort method
         {
           do 
          { swap = 0; 
  
            for (i=0; i < j; i++) 
	     {
              if (st[i].get_gpa() < st[i+1].get_gpa() ) 
                 {  
                   t = st[i]; 
                   st[i] = st[i+1]; 
                   st[i+1] = t; 
                   swap++;
                 }
    	      }
           } while (swap>0);  //end of 2nd sort

         System.out.println ("\nSorted by student GPA in descending order: " );

         for (i=0; i < j+ 1; i++)   //print student sorted by GPA
           {
             System.out.println (st[i].get_name() + "   " + st[i].get_gpa());
            }                
         sort = 100;
        }
      else {System.out.print ("Invalid option! : "); option = 4;}

     System.out.print ("Enter 4 for another sort , enter 5 to exit : ");             
     option = Integer.parseInt (stdin.readLine());

     if (option!=4)
       option = 111;  // exit the program
        
   }
    


   }

}