module PowerTools
  module Builtins
    module Time
      
      DATE_FORMATS = {
        :time => '%H:%M',
        :date => '%d/%m/%y'
      }
      
      module Utilities
        
        def to(to, with_time=false, format_string="%H:%M %d %b '%y")
          fp = format_string.split ' '
          from_date = with_time ? "#{self.part_format(fp[0,1])} " : ''
          to_date = with_time ? "#{to.part_format(fp[0,1])} " : ''
          
          from_date << self.day.ordinalize
          to_date << to.day.ordinalize
          
          if self.year != to.year
            "#{from_date} #{self.part_format(fp[-2,2])} - #{to_date} #{to.part_format(fp[-2,2])}"
          elsif self.month != to.month || (with_time && self.day != to.day)
            "#{from_date} #{self.part_format(fp[-2,1])} - #{to_date} #{to.part_format(fp[-2,1])} #{to.part_format(fp[-1,1])}"
          elsif self.day != to.day
            "#{from_date} - #{to_date} #{to.part_format(fp[-2,2])}"
          elsif !with_time
            "#{from_date} #{to.part_format(fp[-2,2])}"
          else
            "#{self.part_format(fp[0,1])} - #{to_date} #{to.part_format(fp[-2,2])}"
          end
        end
        
        def part_format(parts)
          strftime(parts.join(' '))
        end
        
      end
      
    end
    
    module Integer

      def of(thing)
        if self == 1
          "1 #{thing}"
        else
          "#{self.to_s} #{thing.pluralize}"
        end
      end
        
    end
  end
end

Integer.class_eval do
  include PowerTools::Builtins::Integer
end

Time.class_eval do
  include PowerTools::Builtins::Time::Utilities
end

ActiveSupport::CoreExtensions::Time::Conversions::DATE_FORMATS.update(PowerTools::Builtins::Time::DATE_FORMATS)