package wynnbe01_Project2;

import java.util.Scanner;
import java.io.*;


/*
 * Brandon Wynn
 * CS160-05 Fall
 * Project 2
 */


public class ExamStatistics {


	static int gradeA = 85;
	static int gradeB = 75;				// static integers in the class, but outside of the main method, as requested, to store lower limits of each grade.
	static int gradeC = 65;
	static int gradeD = 55;

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


		int next;  			// to hold place for next integer
		int total = 0; 		// Total number of exams
		int minScore = 100;	// the lowest score, initialized at 100, otherwise score would never change from 0
		int maxScore = 0;	// the highest scores

		int totalA = 0;		// Total number of A's
		int totalB = 0;		// Total number of B's
		int totalC = 0;		// Total number of C's
		int totalD = 0;		// Total number of D's
		int totalF = 0;		// Total number of F's

		double aPercentage;	// Percentage of A's
		double bPercentage;	// Percentage of B's
		double cPercentage;	// Percentage of C's
		double dPercentage;	// Percentage of D's
		double fPercentage;	// Percentage of F's

		double sum = 0.0; 	// total sum of all exam scores, initialized as 0.0 because it will be a running total.
		double average; 	// average scores of all exam scores
		double psd = 0;		// population standard deviation of exam scores

	Scanner keyboard = new Scanner(System.in);
	System.out.println("Enter the file name to be tested:");
	String filename = keyboard.nextLine();						// solicits the user for the filename to be tested and stores name under "file"

	File file = new File(filename);


	while (!file.exists())
	{
		System.out.println("File does not exist");
		System.out.println("Enter the file name to be tested:");
		filename = keyboard.nextLine();

	}

	Scanner inputFile = new Scanner(file);

	while (inputFile.hasNext())
	{ next = inputFile.nextInt();
		sum = sum + next;
		total = total + 1;


		if(next > maxScore)
			{
			maxScore = next;
			}

		if(next < minScore)
			{
			minScore = next;
			}


		if(next< gradeD)
			{
			totalF = totalF + 1;
			}
		else if(next< gradeC)
			{
			totalD = totalD + 1;
			}

		else if(next< gradeB)
			{
			totalC = totalC + 1;
			}
		else if(next< gradeA)
			{
			totalB = totalB + 1;
			}
		else if(next> gradeA)
			totalA = totalA + 1;
		else
			System.out.println("Invalid score");
	}

	inputFile.close();	// To close scanner


	average = (Math.round((sum/total)*100.0)/100.0);							// To calculate average while also rounding to 2 decimal digits

	aPercentage = (Math.round((totalA * 100) / (total*1.0)*100.00)/100.00);		// To calculate percentage of A's while also rounding to 2 decimal digits.
	bPercentage = (Math.round((totalB * 100) / (total*1.0)*100.00)/100.00);		// To calculate percentage of B's while also rounding to 2 decimal digits.
	cPercentage = (Math.round((totalC * 100) / (total*1.0)*100.00)/100.00);		// To calculate percentage of C's while also rounding to 2 decimal digits.
	dPercentage = (Math.round((totalD * 100) / (total*1.0)*100.00)/100.00);		// To calculate percentage of D's while also rounding to 2 decimal digits.
	fPercentage = (Math.round((totalF * 100) / (total*1.0)*100.00)/100.00);		// To calculate percentage of F's while also rounding to 2 decimal digits.




	File filePSD = new File(filename);
	Scanner inputPSD = new Scanner(filePSD);


	if (!filePSD.exists())
	{
		System.out.println("File does not exist");
	}

	while (inputPSD.hasNext())
	{ next = inputPSD.nextInt();
		psd = psd + (average - next) * (average - next);





	}

	psd =(Math.round((Math.sqrt(psd / total))*100.0)/100.0); // Calculating PSD while also rounding it to 2 decimal digits

	inputPSD.close(); // To close Scanner






	String message = "Exam Statistics \n "										// Composing message using String variable so literals do not need to be used.
			+ "\nTotal: " + total
			+ "\nAverage score: " + average
			+ "\nPopulation standard deviation of the scores: " + psd
			+ "\n# of A, 85-100:\t" + totalA + "\t" + aPercentage + "%"
			+ "\n# of B, 75--84:\t" + totalB + "\t" + bPercentage + "%"
			+ "\n# of C, 65--74:\t" + totalC + "\t" + cPercentage + "%"
			+ "\n# of D, 55--64:\t" + totalD + "\t" + dPercentage + "%"
			+ "\n# of F, 00--54:\t" + totalF + "\t" + fPercentage + "%"
			+ "\nMinimum score: " + minScore
			+ "\nMaximum score: " + maxScore
			;



System.out.println(message);

PrintWriter outputFile = new PrintWriter("ScoreStatistics.txt");

outputFile.println(message);


// Formatting of 'message' when using PrintWriter doesn't work when using notepad. When using notepad++, formatting is fine. But since it didn't work properly with notepad,
// I went ahead and wrote a literal message that will look right for notepad.

/*outputFile.println("Exam Statistics");
outputFile.println(" ");
outputFile.println("Total: " + total);
outputFile.println("Population standard deviation of the scores: " + psd);
outputFile.println("# of A, 85-100: " + totalA + "       " + aPercentage + "%");
outputFile.println("# of B, 75--84: " + totalB + "       " + bPercentage + "%");
outputFile.println("# of C, 65--74: " + totalC + "       " + cPercentage + "%");
outputFile.println("# of D, 55--64: " + totalD + "       " + dPercentage + "%");
outputFile.println("# of F, 00--54: "  + totalF + "       " + fPercentage + "%");
outputFile.println("Minimum score: " + minScore);
outputFile.println("Maximum score: " + maxScore);
*/
outputFile.close(); // To close PrintWriter
keyboard.close();	// To close input scanner

System.exit(0);
	}

}