// CSE 142 Winter 2008, Marty Stepp
//
// This program reads an input file of data about students' attendance in
// section and outputs the attendance, points earned, and grade percentages
// for each student in each section.
//
// This second version breaks the program into methods for better structure
// using arrays as parameters and returns.  It also outputs to a file.

import java.io.*;     // for File, PrintStream
import java.util.*;   // for Scanner

public class Sections2 {
	public static final int MAX_POINTS = 20;

	public static void main(String[] args) throws FileNotFoundException {
		PrintStream output = new PrintStream(new File("section_output.txt"));
		Scanner input = new Scanner(new File("sections.txt"));

		while (input.hasNextLine()) {
			// process a student
			String line = input.nextLine();
			int[] students = computeAttended(line);
			int[] scores = computePoints(students);
			double[] percentages = computeGrades(scores);

			// to print to the console instead:
			// results(students, scores, percentages, System.out);
			
			results(students, scores, percentages, output);
		}
	}
	
	// Prints the overall output about a section.
	public static void results(int[] students, int[] scores, double[] percentages,
			PrintStream output) {
		output.println("Sections attended: " + Arrays.toString(students));
		output.println("Student scores: " + Arrays.toString(scores));
		output.println("Student grades: " + Arrays.toString(percentages));
		output.println();
	}
	
	// Reads the given line and computes each student's sections attended.
	public static int[] computeAttended(String line) {
		int[] students = new int[5];
		for (int i = 0; i < line.length(); i++) {
			char c = line.charAt(i);
			if (c == '1') {
				// student went to class!
				// string "111111101011111101001110110110110001110010100"
				// index   01234567890123456789
				// student 012340123401234
				students[i % 5]++;
			}
		}
		
		// "chaining" - method A calls B, B calls C, C calls D, ... no returns
		//     Chaining is bad because:
		//     (a) main is not a good summary of the program
		//     (b) the methods are forever linked; can't call them separately
		
		return students;
	}
	
	// Computes each student's points earned, based on the sections attended.
	public static int[] computePoints(int[] students) {
		int[] scores = new int[5];
		for (int i = 0; i < students.length; i++) {
			scores[i] = Math.min(20, students[i] * 3);
		}
		return scores;
	}
	
	// Computes each student's grade, based on the points earned.
	public static double[] computeGrades(int[] scores) {
		double[] percentages = new double[5];
		for (int i = 0; i < scores.length; i++) {
			percentages[i] = 100.0 * scores[i] / MAX_POINTS;
		}
		return percentages;
	}
}