# License: AGPL-3.0-or-later WITH Web-Template-Output-Additional-Permission-3.0-or-later
# For tracking and calculating timespans/time intervals
# Relies on activesupport

Timespan = Struct.new(:interval, :time_unit) do

	Units = ['week', 'day', 'month', 'year']
  TimeUnits = {
    '1_week' => 1.week.ago,
    '2_weeks' => 2.weeks.ago,
    '1_month' => 1.month.ago,
    '3_months' => 3.months.ago,
    '6_months' => 6.months.ago,
    '1_year' => 1.year.ago,
    '2_years' => 2.years.ago
  }

	# Test if end_date is past start_date by timespan
	# eg: later_than_by?(Jun 13th, Jul 14th, 1.month) -> true
	# Special case:
	# later_than_by?(Jan 31st, Feb 28th, 1.month) -> true
	def self.later_than_by?(start_date, end_date, timespan)
		return (start_date + timespan) <= end_date
	end

	# Given an Integer (frequency) and a String (time unit),
	# return the timespan object (ie. number of seconds) constituting the timespan
	# timespan(1, 'minute') -> 60
	# timespan(1, 'month') -> 2592000
	def self.create(interval, time_unit)
		raise(ArgumentError, "time_unit must be one of: #{Units}") unless Units.include?(time_unit)
		return interval.send(time_unit.to_sym)
	end

	def self.in_future?(datetime)
		datetime > Time.current
	end

	def self.date_now_or_in_future?(date)
		date >= Date.today
	end

	def self.in_past?(date)
		date < Time.current
	end

end