ゴミの日を返すDateTime::kind_of_separated_refuse

gistfile1.rb

#!/usr/bin/ruby
# -*- coding: utf-8 -*-
# kind of separated refuse
# written by moyashi
# 2011.03.02

require 'date'

# grabbed from http://rubyist.g.hatena.ne.jp/yamaz/20070125
class Object
  def enum(*list)
    mc = Module === self ? self : self.class
    list.flatten.each_with_index{|e, i| mc.const_set e.to_s.intern, i}
  end
  def bit_enum(*list)
    mc = Module === self ? self : self.class
    list.flatten.each_with_index{|e, i| mc.const_set e.to_s.intern,  2 ** i}
  end
end

class DateTime

  enum %w(SUN MON TUE WED THU FRI SAT)
  # N = NONE
  # K = KANEN
  # F = FUNEN
  # S = SHIGEN
  # P = PET
  enum %w(N K F S P)

  enum %w(SHORT LONG SLONG)

  LABELS = []
  LABELS[N] = ["無", "無し", "回収無し"]
  LABELS[K] = ["可", "可燃", "可燃ごみ"]
  LABELS[F] = ["不", "不燃", "不燃ごみ"]
  LABELS[S] = ["資", "資源", "資源ごみ"]
  LABELS[P] = ["P", "PET", "PETボトル"]
  
  # 各行は書くまでもなく曜日別、曜日の中に各週の分別ゴミの種別を配列として入れる
  # うちの近所では第一第三水曜は不燃、第二第四水曜はペットボトルといった具合なので
  # 「月曜は週を問わず資源ゴミ」という場合は、四つすべて同じく「資源」を入れておく
  SEPARATED_REFUSES = {
    SUN => [N, N, N, N],
    MON => [S, S, S, S],
    TUE => [K, K, K, K],
    WED => [F, P, F, P],
    THU => [N, N, N, N],
    FRI => [K, K, K, K],
    SAT => [N, N, N, N]
  }

  # 月の何週目か
  def mweek
    return self.cweek - (DateTime.new(self.year, self.mon).cweek - 1)
  end

  # 分別ゴミの種別を文字列で返す
  # 翌日朝のゴミの種別を告知する目的で、半日前倒しでゴミの種別を決定
  # 日曜日の正午から月曜日の正午まで月曜の資源ゴミを返し
  # 月曜日の正午以降は火曜日の可燃ゴミを返すといった具合
  def kind_of_separated_refuse(format)
    # 半日後
    halfAfterDay = self + 0.5
    return LABELS[SEPARATED_REFUSES[halfAfterDay.wday][halfAfterDay.mweek - 1]][format]
  end

end

puts DateTime.now.kind_of_separated_refuse(DateTime::LONG)