module Hizuke::HolidayCalculator

def calculate_christmas_date
  current_year = Date.today.year
  christmas_date = Date.new(current_year, 12, 25)
  # If Christmas has already passed this year, return next year's Christmas
  if Date.today > christmas_date
    Date.new(current_year + 1, 12, 25)
  else
    christmas_date
  end
end

def calculate_holiday_date(date_value)
  case date_value
  when :christmas
    calculate_christmas_date
  when :next_christmas
    calculate_next_christmas_date
  when :last_christmas
    calculate_last_christmas_date
  end
end

def calculate_last_christmas_date
  current_year = Date.today.year
  Date.new(current_year - 1, 12, 25)
end

def calculate_next_christmas_date
  current_year = Date.today.year
  Date.new(current_year + 1, 12, 25)
end