class MajorityJudgment

  @values = nil

  include Comparable
  attr_reader :ratings, :count, :n, :majority

  class << self
    attr_accessor :values
  end

  def initialize(arg)
    if arg.is_a?(Array)
      @ratings = arg
      @count = { }
      self.class.values.each do |v|
        @count[v[:id]] = 0
      end
      @n = 0
      ratings.each do |r|
        @count.has_key?(r) ? @count[r] = @count[r] + 1 : @count[r] = 1
        @n = @n + 1
      end
    elsif arg.is_a?(Hash) 
      @count = arg
      @n = 0
      @count.collect { |r, c| @n = @n + c }
    end
    @majority = ( @n.to_f / 2 ).floor + 1
  end

  def mj
    s = 0
    (1..self.class.values.length).to_a.reverse.each do |r|
      s = s + @count[r] if @count[r]
      return r if s >= @majority
    end
    return 0
  end

  def proponents(rating = self.mj)
    p = 0
    (rating+1..self.class.values.length).to_a.reverse.each do |r|
      p = p + @count[r] if @count[r]
    end
    return p
  end

  def opponents(rating = self.mj)
    o = 0
    (1..rating-1).to_a.reverse.each do |r|
      o = o + @count[r] if @count[r]
    end
    return o
  end

  def <=> (other)
    return 1 if self.mj > other.mj
    return -1 if self.mj < other.mj
    return 0 if self.mj == 0
    counta = self.count.dup
    counta[self.mj] = counta[self.mj] - 1
    countb = other.count.dup
    countb[other.mj] = countb[other.mj] - 1
    return MajorityJudgment.new(counta) <=> MajorityJudgment.new(countb)
  end

  def break_tie(other)
    rounds = [ ]
    s = MajorityJudgment.new(self.count.dup)
    o = MajorityJudgment.new(other.count.dup)
    rounds << [s, o]
    while s.mj == o.mj and not s.mj == 0
      new_s_count = s.count.dup
      new_o_count = o.count.dup
      new_s_count[s.mj] = new_s_count[s.mj] - 1
      new_o_count[o.mj] = new_o_count[o.mj] - 1
      s = MajorityJudgment.new(new_s_count)
      o = MajorityJudgment.new(new_o_count)
      rounds << [s, o]
    end
    return rounds
  end

  def to_s
    puts "#{@count}: {M=>#{self.mj}, P=>#{self.proponents}, O=>#{self.opponents}}"
  end

end