RPCFN #10

business_hours.rb

require 'time'

class BusinessHours
  def initialize opening, closing
    @hours = Hash.new( [opening, Time.parse(closing)-Time.parse(opening)] )
  end

  def calculate_deadline interval, drop_off
    target = seconds_before_closing( time = Time.parse(drop_off) )

    target += open_hours( time += 86400 ).last while target < interval

    time_after_opening( time, interval - (target - open_hours(time).last) )
  end

  def closed  *dates
    dates.each { |date| @hours[date] = ["12:00 PM", 0] } 
  end

  def update day, opening, closing
    @hours[day] = [ opening, Time.parse(closing)-Time.parse(opening) ]
  end

  private

  def time_to_day time
    Time::RFC2822_DAY_NAME[string_or_time(time).wday].downcase.to_sym
  end

  def time_to_date time
    string_or_time(time).strftime("%b %d, %Y")
  end

  def string_or_time time
    time.is_a?(String) ? Time.parse(time) : time 
  end
  
  def open_hours time
    @hours.fetch(time_to_date time) { @hours[time_to_day time] }
  end

  def seconds_before_closing time
    open_hours(time).last -  (time - Time.parse(open_hours(time).first, time) )
  end

  def time_after_opening time, interval
    Time.parse(open_hours(time).first, time) + interval
  end
end

business_hours_spec.rb

require 'business_hours'

describe BusinessHours do
  subject { 
    bh = BusinessHours.new "9:00 AM", "3:00 PM" 
    bh.update :fri, "10:00 AM", "5:00 PM" 
    bh.update "Dec 24, 2010", "8:00 AM", "1:00 PM" 
    bh.closed :sun, :wed, "Dec 25, 2010" 
    bh
  }
  
  it { subject.send(:open_hours,"Dec 31, 2010").should == ["10:00 AM", Time.parse("5:00 PM") - Time.parse("10:00 AM")] }
  it { subject.send(:open_hours,"Dec 24, 2010").should == ["8:00 AM", Time.parse("1:00 PM") - Time.parse("8:00 AM")] }
  it { subject.send(:open_hours,"Dec 23, 2010").should == ["9:00 AM", Time.parse("3:00 PM") - Time.parse("9:00 AM")] }

  it { ["Dec 19, 2010","Dec 22, 2010","Dec 25, 2010"].each { |date| subject.send(:open_hours,date).last == 0 } }

  it { subject.send(:seconds_before_closing,Time.parse("Dec 31, 2010 4:00 PM")).should == 60*60 }
  it { subject.send(:seconds_before_closing,Time.parse("Dec 31, 2010 10:00 AM")).should == 7*60*60 }

  it { subject.send(:time_after_opening,Time.parse("Dec 31, 2010"), 3600).should == Time.parse("Dec 31, 2010 11:00 AM") }
  it { subject.send(:time_after_opening,Time.parse("Dec 31, 2010 6:00 PM"), 3600).should == Time.parse("Dec 31, 2010 11:00 AM") }

  it { subject.calculate_deadline(2*60*60, "Jun 7, 2010 9:10 AM").should == Time.parse("Mon Jun 07 11:10:00 2010") }
  it { subject.calculate_deadline(15*60, "Jun 8, 2010 2:48 PM").should == Time.parse("Thu Jun 10 09:03:00 2010") }
  it { subject.calculate_deadline(15*60, "Jun 8, 2010 2:48 PM").should == Time.parse("Thu Jun 10 09:03:00 2010") }
end