appointment_book.rb

require "date"
require "pstore"

class Schedule


  include Enumerable

  def initialize(file="schedule.store")
    @store = PStore.new(file)
  end

  def [](date)
    @store.transaction do
      events_for(date)
    end
  end

  def event(date, text)
    @store.transaction do
      events_for(date) << text
    end
  end
  
  def event_update(date, index, text)
  	@store.transaction do
  		events_for(date)[index].replace(text)
		end
	end
  
  def empty?
  	@store.roots.empty?
	end
  
	#remove entire date  
  def clear_date(date)
  	@store.transaction do
  		@store.delete(to_date(date))
		end
	end

	#remove a single event
	def remove(date, index)
		@store.transaction do
			events_for(date).delete_at(index)
		end
	end

  def each
    @store.transaction do
      @store.roots.sort.each { |date| yield([date, @store[date]]) }
    end
  end

  def to_s
    map do |(date, appointments)|
      date.strftime("%m/%d/%Y") + " (#{appointments.length})"
    end.join("\n")
  end

  private

  def events_for(date)
    @store[to_date(date)] ||= []
  end

  def to_date(str)
    Date.strptime(str, "%m/%d/%Y")
  end

end