student_in_cohort.rb

class Student < LocalCohort
  attr_reader :student_name, :email, :history, :local_cohort

  def initialize(student_name, email, local_cohort)
    @student_name, @email, @local_cohort = student_name, email, local_cohort
    @history = []
  end

  def grade
    events = history.select{|event| event[1].is_a?(Fixnum)}
    return "No grades yet" if events.empty?
    events.map{|set| set[1]}.inject(:+) / events.length
  end

  def add_history(event)
    @history << event
  end

  def local_cohort_name
    local_cohort.city
  end

  def global_cohort_name
    local_cohort.global_cohort_name
  end

  def currently_in_phase
    local_cohort.global_cohort.currently_in_phase
  end
end