/* Alvin Bello
 * Block 6
 * Grade Book Lab
 */

package main;

import java.text.DecimalFormat;
import java.util.InputMismatchException;
import java.util.Scanner;

public class Main {

	static Scanner scan = new Scanner(System.in);
	String[][] grades;
	int students, tests, avg;
	DecimalFormat dec;

	public static void main(String args[]) {
		int students = 0;
		while(true) {
			try {
				while(students < 1 || students > 30) {
					System.out.println("How many students do you want? You must have at least 1 and at most 30.");
					students = scan.nextInt();
				}
			} catch (InputMismatchException e) {
				System.out.println("Students are integers -_-");
				scan.nextLine();
	        continue;
	      	} catch (Exception e) {
				System.out.println("An unexpected exception occured, lets try again.");
				scan.nextLine();
				continue;
	      	}
			break;
		}
	    while(true) {
			try {
				System.out.println("How many tests will you have? If you enter a negative amount you will have 0");
				int tests = scan.nextInt();
				tests = (tests < 0) ? 0 : tests;
				scan.nextLine();
				Main run = new Main(students, tests);
			} catch (InputMismatchException e) {
				System.out.println("You must have an integral amount of tests -_-");
				scan.nextLine();
				continue;
	      	} catch (Exception e) {
				System.out.println("An unexpected exception occured, lets try again.");
				scan.nextLine();
				continue;
	      	}
			break;
	    }
	}

	public Main(int students, int tests) {
		this.students = students;
		this.tests = tests;
		grades = new String[students+1][tests+3];
		grades[0][0] = "";
		grades[0][grades[0].length-2] = "Average";
		grades[0][grades[0].length-1] = "Grade";
		dec = new DecimalFormat("0.##");
		while(true) {
			try {
				System.out.println("Now let's enter the names of your students");
				for(int i = 1; i < grades.length; i++) {
					System.out.println("Enter the name of student " + i);
					grades[i][0] = scan.nextLine();
				}
			} catch (Exception | Error e) {
				System.out.println("You messed up");
				scan.nextLine();
				continue;
			}
			break;
		}
		while(true) {
			try {
				System.out.println("Now let's enter the names of your tests.\n");
				for(int i = 1; i < grades[0].length-2; i++) {
					System.out.println("Enter the name of test " + i);
					grades[0][i] = scan.nextLine();
				}
			} catch (Exception | Error e) {
				System.out.println("You messed up");
				scan.nextLine();
				continue;
			}
			break;
		}
		while(true) {
			try {
				System.out.println("Now let's enter the scores of the students.\n");
				for(int i = 1; i < grades.length; i++) {
					for(int j = 1; j < grades[i].length-2; j++) {
						System.out.println("Enter " + grades[i][0] + "\'s grade for test " + grades[0][j]);
						double score = scan.nextDouble();
						score = score<0?0:score;
						grades[i][j] = dec.format(score);
					}
				}
			}  catch (InputMismatchException e) {
				System.out.println("I told you to enter numbers! Now we have to start over.");
				scan.nextLine();
				continue;
	        } catch (Exception e) {
				System.out.println("An unexpected exception occured, lets try again.");
				scan.nextLine();
				continue;
	        }
			break;
		}
		for(int i = 1; i < grades.length; i++) {
			for(int j = 1; j < grades[i].length-2; j++)
				avg += Double.parseDouble(grades[i][j]);
			avg /= grades[i].length-3;
			grades[i][grades[i].length-2] = dec.format(avg);
			if(avg >= 89.5) grades[i][grades[i].length-1] = "A";
			else if(avg >= 79.5) grades[i][grades[i].length-1] = "B";
			else if(avg >= 69.5) grades[i][grades[i].length-1] = "C";
			else if(avg >= 59.5) grades[i][grades[i].length-1] = "D";
			else if(avg < 59.5) grades[i][grades[i].length-1] = "F";
		}
		System.out.println("Here is your class:\n");
		for(int i = 0; i < grades.length; i++) {
			for(int j = 0; j < grades[i].length; j++)
				System.out.print(grades[i][j] + "\t");
			System.out.println();
		}
		System.out.println("Here are your test averages:\n");
		double testAvg = 0;
		for(int j = 1; j < grades[0].length-2; j++) {
			for(int i = 1; i < grades.length; i++)
				testAvg += Double.parseDouble(grades[i][j]);
			testAvg /= grades.length - 1;
			System.out.println("The average for " + grades[0][j] + " is " + testAvg);
		}
	}
}