// Reads an input file containing attendance information and reporting for each
// student their attendance for each day of the week and calculating which day's 
// lectures were attended most frequently. 

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

public class AttendanceFinal {
   public static void main(String[] args) throws FileNotFoundException {
      Scanner input = new Scanner(new File("attendance.txt"));
      
      // each line has meaning (each line is a different student)
      int studentCount = 0;
      while (input.hasNextLine()) {
         String attendanceLine = input.nextLine();
         studentCount++;
         // process entire line / entire attendance data for one student
         
         // count attendance on each day (process String from input file)
         /*
            we have two options regarding weekdayCount array:
               1) can create the array here (where we call the counting method) and pass the 
                     array reference as a parameter
               2) the counting method creates array AND returns it
               
            below we show option 2
         */
         int[] weekdayCount = countAttendance(attendanceLine);
         
         // figure out which day was attended most often
         String mostAttendedDay = findMostAttendedDay(weekdayCount);
         
//          String mostAttendedDay;
//          if (maxIndex == 0) {
//             mostAttendedDay = "Mon";
//          } else if (maxIndex == 1) {
//             mostAttendedDay = "Tues";
//          } else if (maxIndex == 2) {
//             mostAttendedDay = "Wed";
//          } else if (maxIndex == 3) {
//             mostAttendedDay = "Thurs";
//          } else {
//             mostAttendedDay = "Fri";
//          }
         
         // print results 
         printResults(studentCount, weekdayCount, mostAttendedDay);
      }
   }
   
   // Uses the given line of attendance information to tally up the number 
   // of times each weekday was attended and returns an array of these counts
   // with Monday attendance at index 0, Tuesday attendance at index 1, etc.
   // String attendanceLine: the String containing attendance information 
   // data transformation:
   //       attendance string --> array of counts for each weekday 
   public static int[] countAttendance(String attendanceLine) {
      int[] weekdayCount = new int[5];
      for (int i = 0; i < attendanceLine.length(); i++) {   // String traversal
         char next = attendanceLine.charAt(i);
         if (next == 'y') {
            // increment attendance for one of the days
            weekdayCount[i % 5]++;
         }
      }
      return weekdayCount;
   }
   
   // Uses the given count of weekday attendance and returns a String of the weekday
   // that had the highest attendance. 
   // int[] weekdayCount: the array containing the number of times the student 
   //                      attended each weekday lecture
   // data transformation: 
   //       array of counts for each weekday --> weekday with highest attendance
   public static String findMostAttendedDay(int[] weekdayCount) {
      int maxIndex = 0;
      for (int i = 1; i < weekdayCount.length; i++) {
         int nextCount = weekdayCount[i];
         int prevMax = weekdayCount[maxIndex];
         if (nextCount > prevMax) {
            // remember, i corresponds to which day we're looking at
            maxIndex = i;
         }
      }
      
      // "look up" array to look up which day an index corresponds to
      String[] weekdayLookUp = {"Mon", "Tues", "Wed", "Thurs", "Fri"};
      String mostAttendedDay = weekdayLookUp[maxIndex];
      return mostAttendedDay;
   }
   
   // Prints to the console the number of lectures the given student attended on each 
   // weekday, and reports the day that was attended most often. 
   // int studentCount: which student the report is for
   // int[] weekdayCount: the array containing the number of times the student 
   //                      attended each weekday lecture
   // mostAttendedDay: the weekday that had the highest attendance
   public static void printResults(int studentCount, int[] weekdayCount, String mostAttendedDay) {
      System.out.println("Student #" + studentCount + "'s attendance data:");
      System.out.println("    M  T  W  Th F");
      System.out.println("   " + Arrays.toString(weekdayCount));
      System.out.println("   Attended " + mostAttendedDay + " lectures most often.");
      System.out.println();
   }
}