module Calculations

# File lib/period_dates/core_ext.rb, line 5
def available_periods
  ["monthly","quarterly","biannually","semestral"]
end

# File lib/period_dates/core_ext.rb, line 61
def current_period_dates(period='monthly')
    bound_dates = []

    if period == 'monthly'
      bound_dates[0] = self.at_beginning_of_month
      bound_dates[1] = self.at_end_of_month
    end

    if period == 'quarterly'
      bound_dates[0] = self.at_beginning_of_quarter
      bound_dates[1] = self.at_end_of_quarter
    end

    if period == 'biannually' or period == 'semestral'
      bound_dates[0] = self.at_beginning_of_semester
      bound_dates[1] = self.at_end_of_semester
    end

    if !available_periods.include?(period)
      raise PeriodDatesIncorrectPeriod, "Period must be one of this: #{available_periods.join(', ')}."
    else
      bound_dates
    end
end

# File lib/period_dates/core_ext.rb, line 36
def next_period_dates(period='monthly')
    bound_dates = []

    if period == 'monthly'
      bound_dates[0] = self.next_month.at_beginning_of_month
      bound_dates[1] = self.next_month.at_end_of_month
    end

    if period == 'quarterly'
      bound_dates[0] = self.next_quarter.at_beginning_of_quarter
      bound_dates[1] = self.next_quarter.at_end_of_quarter
    end

    if period == 'biannually' or period == 'semestral'
      bound_dates[0] = self.next_semester.at_beginning_of_semester
      bound_dates[1] = self.next_semester.at_end_of_semester
    end

    if !available_periods.include?(period)
      raise PeriodDatesIncorrectPeriod, "Period must be one of this: #{available_periods.join(', ')}."
    else
      bound_dates
    end
end

# File lib/period_dates/core_ext.rb, line 86
def offset_period_dates(offset=0,period='monthly')
    bound_dates = self.current_period_dates(period)

    if !available_periods.include?(period)
      raise PeriodDatesIncorrectPeriod, "Period must be one of this: #{available_periods.join(', ')}."
    else
      offset.abs.times do |time|
        if offset > 0
          bound_dates = bound_dates[0].next_period_dates(period)
        elsif offset < 0
          bound_dates = bound_dates[0].prev_period_dates(period)
        end
      end

      bound_dates
    end
end

# File lib/period_dates/core_ext.rb, line 9
def prev_period_dates(period='monthly')
    bound_dates = []

    if period == 'monthly'
      bound_dates[0] = self.prev_month.at_beginning_of_month
      bound_dates[1] = self.prev_month.at_end_of_month
    end

    if period == 'quarterly'
      bound_dates[0] = self.prev_quarter.at_beginning_of_quarter
      bound_dates[1] = self.prev_quarter.at_end_of_quarter
    end

    if period == 'biannually' or period == 'semestral'
      bound_dates[0] = self.prev_semester.at_beginning_of_semester
      bound_dates[1] = self.prev_semester.at_end_of_semester
    end

    if !available_periods.include?(period)
      raise PeriodDatesIncorrectPeriod, "Period must be one of this: #{available_periods.join(', ')}."
    else
      bound_dates
    end
end