import java.io.*;

/*
==========================================

ONYEN: jqpublic
NAME: John Q. Public

ASSIGNMENT:  A7

CLASS: COMP 110-004 fall 2010
INSTRUCTOR: Stotts

==========================================
*/


class HW7 {


 public static void main (String[] args) throws IOException {
	 int i;
	 String line;
   // get two run line arguments (2 integers)
	int NSTUDENTS = Integer.parseInt(args[0]);
	int NGRADES = Integer.parseInt(args[1]);

	if (NSTUDENTS <= 0){
		System.out.println("Number of students must be greater than 0");
		return;
	}
	if (NGRADES <= 0){
		System.out.println("Number of grades must be greater than 0");
		return;
	}
   // create an array of Student objects
	Student[] people = new Student[NSTUDENTS];
	Student stu;

	Prompter prompter;

	// create the Student objects and fill them
	// use a for loop
	for ( i = 0; i < NSTUDENTS; i++ ) {
	   // access each slot in the array
		int year;
		// create a new student object
	    stu = new Student(NGRADES);
	    prompter = new Prompter();
		// fill the student object with info
		// typed at the keyboard
	    line =  prompter.prompt("Input first name: ");
		stu.setFname(line); // of course, you have to get the line
		                    // from the user, convert to num if needed

		line = prompter.prompt("Input last name: ");
		stu.setLname(line);

		line = prompter.prompt("Input major: ");
		stu.setMajor(line);

		line = prompter.prompt("Input year: ");
		year = Integer.parseInt(line);
		if ( year <= 0 || year > 5){
			System.out.println("Year must be 1 through 5");
			return;
		}
		stu.setYear(year);

		// store the filled student object in the current array slot
	   people[i] = stu;
	}


	// go into a forever loop
	while(true){
	     // show the menu
		System.out.println("Select an action to perform: "
				+ "\n  0 - quit"
				+ "\n  1 - show class roster (showing grade average for each student)"
				+ "\n  2 - add an exam grade for all students"
				+ "\n  3 - show student information"
				+ "\n  4 - show class average"
				+ "\n  5 - show overall average for a specific major"
				+ "\n  6 - show overall average for a specific year"
				+ "\n  7 - show class \"distribution\"... how many A's, B's, C's, D's, F's");

		  // get user selection as keyboard input
	    prompter = new Prompter();
	    int userSelection = Integer.parseInt(prompter.prompt(""));
	    int count;

		  // switch statement on user selection
		  switch (userSelection) {
		    case 0:
			   System.out.println("quitting...");
				System.exit(0); // ends the program
				break;
			 case 1:
			   System.out.println("show class roster");
				doShowRoster(people);
			   break;
			 case 2:
			   System.out.println("add grade to each student");
				doAddGrades(people);
		      break;
			 case 3:
				 String name = prompter.prompt("Enter student name \"first last\": ");
				 for (i = 0; i < NSTUDENTS; i++){
					 if (name.equalsIgnoreCase(people[i].getName())){
						 System.out.println(people[i].getName()
								 + ", " + people[i].getMajor()
								 + ", " + people[i].getYear()
								 + "\n" + people[i].getGrades()
								 + "\n" + people[i].getAverage());
					 }
				 }
				 break;
			 case 4:
				 double average = 0;
				 for (i = 0; i < NSTUDENTS; i++){
					 average += people[i].getAverage();
				 }
				 average = average / NSTUDENTS;
				 System.out.println("Class average: " + average);
				 break;
			 case 5:
				 String major = prompter.prompt("Enter which major: ");
				 average = 0;
				 count = 0;
				 for (i = 0; i < NSTUDENTS; i++){
					 if (major.equalsIgnoreCase(people[i].getMajor())){
						 average += people[i].getAverage();
						 count += 1;
					 }
				 }
				 average = average / count;
				 System.out.println("Average for " + major + ": " + average);
				 break;
			 case 6:
				 int year = Integer.parseInt(prompter.prompt("Enter which year: "));
				 if ( year <= 0 || year > 5){
					System.out.println("Year must be 1 through 5");
					break;
				 }
				 average = 0;
				 count = 0;
				 for (i = 0; i < NSTUDENTS; i++){
					 if (year == people[i].getYear()){
						 average += people[i].getAverage();
						 count += 1;
					 }
				 }
				 average = average / count;
				 System.out.println("Average for " + year + ": " + average);
				 break;

			 case 7:
				 int nA = 0;
				 int nB = 0;
				 int nC = 0;
				 int nD = 0;
				 int nF = 0;

				 double grade;
				 for (i = 0; i < NSTUDENTS; i++){
					 grade = people[i].getAverage();
					 if (grade >= 90){
						 nA += 1;
					 }
					 else if (grade >= 80){
						 nB += 1;
					 }
					 else if (grade >= 70){
						 nC += 1;
					 }
					 else if (grade >= 60){
						 nD += 1;
					 }
					 else {
						 nF += 1;
					 }
				 }
				 System.out.println("A's: " + nA + " B's: " + nB + " C's: " + nC + " D's: " + nD + " F's: " + nF);
				 break;


			 default:
			   System.out.println("bad selection");
				break;
			}
	}
	// end of the forever loop body

  }

  public static void doShowRoster(Student[] all) { // stub
    // you may need more parameters
	  int i;
	  for (i = 0; i < all.length; i++ ){
		  System.out.println(all[i].getName() + " " + all[i].getAverage());
	  }
  }

  public static void doAddGrades (Student[] all) throws NumberFormatException, IOException { // stub
    // you may need more parameters
	  Prompter prompter = new Prompter();

	  int i;
	  for (i = 0; i < all.length; i++){
		  double grade = Double.parseDouble(prompter.prompt("Enter grade for " + all[i].getName() +": "));
		  if (grade > 0.00 || grade < 100.00){
			  all[i].addGrade(grade);
		  }
		  else {
			  System.out.println("Must be between 0.00 and 100.00");
			  i -= 1;
		  }
	  }

  }


}