class Date
  FOS_JD_OFFSET_DAYS = Date.parse('1899-12-31').jd
  DATE_FORMATS[:mdy] = "%m/%d/%Y"

  def self.from_fos_days(days)
    self.jd(FOS_JD_OFFSET_DAYS + days)
  end

  def to_fos_days
    jd - FOS_JD_OFFSET_DAYS
  end
end

module TimeFunctions

  def as_minutes
    hour*60 + min
  end

  def in_hundredths
    return 0 if hour + min == 0
    minutes = hour*60 + min
    val = "#{minutes/60}.#{((100*(minutes.modulo(60)))/60).to_s.rjust(2, '0')}"
    BigDecimal.new(val, 2).round(1).to_s
  end

  # xos is rounding XOJET STYLE, which is a funky copy of how ipc did it
  def in_hundredths_rounded_xos
    return 0 if hour + min == 0
    # It was determined that "ODD" increments of .05 (ie .15, .35, .55, .75, .95) of an hour (ie. 9,21,33,45,57 minutes) rounded UP whereas even increments of .05 rounded DOWN - sn
    minutes = as_minutes
    (minutes/60.0 + ([9, 21, 33, 45, 57].include?( min ) ? 0.001 : -0.001)).round(2)
  end

  # xos is rounding XOJET STYLE, which is a funky copy of how ipc did it
  def in_tenths_rounded_xos
    return 0 if hour + min == 0
    # It was determined that "ODD" increments of .05 (ie .15, .35, .55, .75, .95) of an hour (ie. 9,21,33,45,57 minutes) rounded UP whereas even increments of .05 rounded DOWN - sn
    minutes = as_minutes
    (minutes/60.0 + ([9, 21, 33, 45, 57].include?( min ) ? 0.01 : -0.01)).round(1)
  end

  def hm
    to_s(:hm)
  end

end

class Time
  include TimeFunctions

  DATE_FORMATS[:hm] = "%H:%M"

  alias :original_to_s :to_s

  def to_s(args=nil)
    args = :hm unless args
    self.original_to_s(args)
  end

  # using a date of 2000,1,1 is arbitrary
  def self.from_fos_time(minutes)
    minutes = 0 unless minutes
    Time.utc(2000, 1, 1) + minutes.minutes
  end

  class << self
    alias from_minutes from_fos_time 
  end
end

class DateTime
  include TimeFunctions

  # creates utc time from days and minutes
  def self.from_fos_date_time(days, minutes)
    days = 0 unless days
    minutes = 0 unless minutes
    Date.from_fos_days(days).to_datetime.advance(:minutes=>minutes)
  end

  def view
    to_s
  end

  # This is a view that be parsed directly by javascript ie. in javascript 
  # you can say:  Date.parse( "this to long view" )   and you will get a date object
  def long_view
    to_s(:long)
  end
end