//
// preliminary/sketch program to compute letter grade based on input 
//   from file, where each line contains the following, separated by spaces:
// name of assignment
// perfect score
// student score
// 
// many improvements are possible
//

import scala.io.StdIn._

// each GradeComponent represents one assignment
case class GradeComponent(name:String, perfectScore:Double, studentScore:Double)

// get input from file (in the form of a list of strings, one per line)
println("enter file name with grades")
val filename = readLine
val src = scala.io.Source.fromFile(filename)
val lines = src.getLines.toList
src.close

// convert each line to a GradeComponent and print
val gradeComponents = lines.map(processLine(_))
println("input:")
gradeComponents.foreach(g =>
  println(g.name + " " + g.studentScore + " out of " + g.perfectScore)
)

// compute average
val studentTotal = gradeComponents.map(_.studentScore).sum
val perfectTotal = gradeComponents.map(_.perfectScore).sum
val average = studentTotal / perfectTotal

// print
println()
println("your total points = " + studentTotal)
println("perfect total points = " + perfectTotal)
println("average = " + average)
if (average >= .90) {
  println("A- or better")
}
else if (average >= .80) {
  println("B- or better") 
}
else if (average >= .70) {
  println("C- or better")
}
else if (average >= .60) {
  println("D- or better")
}
else {
  println("sorry, F")
}

// convert input line to a GradeComponent
def processLine(line:String) : GradeComponent = {
  // get name (string) and two scores (Double) from 'line'
  val inputFields = line.split(" ")
  val grade = GradeComponent(inputFields(0), 
    inputFields(1).toDouble, 
    inputFields(2).toDouble)
  grade
}