# Class to create test grade data.
# This could be a simple script, but I prefer to keep it as a
# class to show the coherence of the methods.
class CreateGradeData
  # Create a data set and print it on standard output
  #
  # @param nStudents - number of students
  # @param types - an array of quatruples, where the elements are: 
  #   name - the name of the type, 
  #   abbreviation - one letter abbreviation, 
  #   points - total number of points for this type of grade,
  #   grades - an array of grades to generate where each element has the form:
  #     high - maximum points
  #     low - minimum points
  #   low - the lowest possible percent grade to generate
  #   high - the highest possible percentgrade to generate
  def CreateGradeData.makeGradeData(nStudents, types)
    puts types.size
    types.each {|i| puts i[0] + " " + i[1] + " " + i[2].to_s}
    studentIds = CreateGradeData.makeStudents(nStudents)
    types.each {|i| CreateGradeData.makeGrades(i, studentIds)}
  end
  
  # Generate grades of a particular type
  # @param type - the type of grade to generate as an array
  # @param sIds - the student IDs
  def CreateGradeData.makeGrades(type, sIds)
    a = type[1]     # abbreviation 
    g = type[3]     # array of generating parameters
    g.each do |i|
      sIds.each{|s| CreateGradeData.generateGrade(s, a, i)}
    end
  end
  
  # Generate one grade
  # @param sId - student ID
  # @param a - abbreviation for the assignment type
  # @param g - generating specification [low, high]
  def CreateGradeData.generateGrade(sId, a, g)
    grade = g[0] + rand(g[1]-g[0]+1)
    puts a + " " + sId.to_s + " " + grade.to_s + " " + g[1].to_s
  end
  
  # Create an array of student IDs. The SIDs will be 5 digits between
  # 10000 and 99999
  def CreateGradeData.makeStudents(nStudents)
    result = []
    (0..(nStudents-1)).each do |i|
      x = 10000 + rand(89999)
      while result.include?(x) do
        x = 10000 + rand(89999)
      end
      result[i] = x
    end
    return result
  end
end

t = [
  ["Quizzes", "Q", 10, [[0, 10], [0, 10], [0, 10], [0, 10], [0, 10], [0, 10]]],
  ["Exams", "E", 25, [[50, 100],[40, 100]]],
  ["Homework", "H", 25, [[5, 25], [10, 50], [15, 50], [8, 20], [0, 15], [5, 20]]],
  ["Project", "P", 30, [[40, 75], [5, 25]]],
  ["Participation", "C", 10, [[0, 10]]]
];

CreateGradeData.makeGradeData(25, t)