# frozen_string_literal: true

# :nodoc:
module Zakuro
  # :nodoc:
  module Calculation
    # :nodoc:
    module Range
      # :nodoc:
      module Transfer
        #
        # WesternDateAllocation 西暦日の割り当て
        #
        module WesternDateAllocation
          #
          # 月初日の西暦日を更新する
          #
          # @param [Context] context 暦コンテキスト
          # @param [Array<Year>] years 完全範囲（月初日なし）
          #
          # @return [Array<Year>] 完全範囲（月初日あり）
          #
          def self.get(context:, years:)
            update_first_day(context: context, years: years)

            years
          end

          #
          # 月初日の西暦日を更新する
          #
          # @param [Context] context 暦コンテキスト
          # @param [Array<Year>] years 完全範囲（月初日なし）
          #
          def self.update_first_day(context:, years:)
            years.each_with_index do |year, index|
              new_year_date = year.new_year_date.clone

              months = year.months
              update_first_day_within_all_months(
                context: context,
                new_year_date: new_year_date, months: months
              )

              years[index] = Base::Year.new(
                multi_gengou: year.multi_gengou, new_year_date: new_year_date,
                months: months, total_days: year.total_days
              )
            end
          end

          #
          # 全ての月で月初日の西暦日を更新する
          #
          # @param [Context] context 暦コンテキスト
          # @param [Western::Calendar] new_year_date 元旦
          # @param [Array<Month>] months 月データ
          #
          def self.update_first_day_within_all_months(context:,
                                                      new_year_date:, months:)
            date = new_year_date.clone
            months.each_with_index do |month, index|
              updated_month = Monthly::Month.new(
                context: context,
                month_label: month.month_label,
                first_day: Monthly::FirstDay.new(
                  remainder: month.first_day.remainder,
                  western_date: date
                ),
                solar_terms: month.solar_terms
              )
              months[index] = updated_month

              date = date.clone + updated_month.days
            end
          end
          private_class_method :update_first_day_within_all_months
        end
      end
    end
  end
end