#!/bin/ruby

require 'time'

# a student who submitted for the assignment
class Student
  attr_reader :name, :section
  def initialize(name, section)
    @name    = name
    @section = section
  end
  def to_s
    "#{@name}, sect #{@section}"
  end
end

# a particular submission for a student
class Submission
  attr_reader :student, :assignment, :diffs, :time
  def initialize(stu, assmnt, diffs, time)
    @student    = stu
    @assignment = assmnt
    @diffs      = diffs
    @time       = time
  end
  def to_s
    @student.to_s + ": #{@diffs} diffs, #{@time.ctime}; score #{score}"
  end
  def score
    if diffs > 0 then
      0
    else
      5
    end
  end
end

# all "final" submissions, organized by submissions
#  - this stores only the LAST submission
class Submits
  def initialize
    @results = {}
  end

  # record a Submission, comparing this submission against previous ones
  #   and keeping only the latest
  def add(sub)
    if @results[sub.student.name] == nil ||
       @results[sub.student.name].time < sub.time then
      #puts "[Storing submission #{sub}]"
      @results[sub.student.name] = sub
    else
      #puts "[NOT adding submission #{sub}]"
    end
  end

  # look up student by name
  def lookup(name)
    r = @results[name]
    if r == nil then
      nil
    else
      r.student
    end
  end

  # load submissions from standard input
  def Submits::load
    subs = Submits.new
    while (line = gets) do
      items = line.chop.split(',')
      stu = subs.lookup(items[0])
      if stu == nil then
        stu = Student.new(items[0], items[1])
      end
      t = Time.parse(items[4])
      subs.add(Submission.new(stu, items[2], items[3].to_i, t))
    end
    return subs
  end

  # return array of final submissions, sorted by student name
  def final_results
    sorted = @results.sort
    # now need to strip off names from each entry
    sorted.map { |x| x[1] }
  end
end

if __FILE__ == $0 then

  all = Submits::load
  res = all.final_results
  res.each { |x| puts x }

end